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Sample records for pair cluster trial

  1. Kappa statistic for clustered matched-pair data.

    Science.gov (United States)

    Yang, Zhao; Zhou, Ming

    2014-07-10

    Kappa statistic is widely used to assess the agreement between two procedures in the independent matched-pair data. For matched-pair data collected in clusters, on the basis of the delta method and sampling techniques, we propose a nonparametric variance estimator for the kappa statistic without within-cluster correlation structure or distributional assumptions. The results of an extensive Monte Carlo simulation study demonstrate that the proposed kappa statistic provides consistent estimation and the proposed variance estimator behaves reasonably well for at least a moderately large number of clusters (e.g., K ≥50). Compared with the variance estimator ignoring dependence within a cluster, the proposed variance estimator performs better in maintaining the nominal coverage probability when the intra-cluster correlation is fair (ρ ≥0.3), with more pronounced improvement when ρ is further increased. To illustrate the practical application of the proposed estimator, we analyze two real data examples of clustered matched-pair data. Copyright © 2014 John Wiley & Sons, Ltd.

  2. PErineal Assessment and Repair Longitudinal Study (PEARLS: protocol for a matched pair cluster trial

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    Thomas Peter W

    2010-02-01

    Full Text Available Abstract Background The Perineal Assessment and Repair Longitudinal Study (PEARLS is a national clinical quality improvement initiative designed to improve the assessment and management of perineal trauma. Perineal trauma affects around 85% of women who have a vaginal birth in the UK each year and millions more world-wide. Continuous suturing techniques compared with traditional interrupted methods are more effective in reducing pain and postnatal morbidity, however they are not widely used by clinicians despite recommendations of evidence based national clinical guidelines. Perineal suturing skills and postnatal management of trauma remain highly variable within and between maternity units in the UK as well as worldwide. Implementation of a standardised training package to support effective perineal management practices could reduce perineal pain and other related postnatal morbidity for a substantial number of women. Methods/Design PEARLS is a matched pair cluster trial, which is being conducted in maternity units across the UK. Units within a matched pair will be randomised to implement the study intervention either early or late in the study period. The intervention will include the cascading of a multi-professional training package to enhance midwifery and obstetric skills in the assessment, repair and postnatal management of perineal trauma. Women who have had an episiotomy or second degree perineal tear will be eligible for recruitment. Prior to developing the intervention and deciding on study outcomes, a Delphi survey and a consensus conference were held to identify what women, who previously suffered perineal trauma during childbirth, considered to be important outcomes for them. Findings from this preliminary work (which will be reported elsewhere and other outcomes including women's experiences of perineal pain and pain on activity, breastfeeding uptake and duration and psychological well-being as assessed using the Edinburgh

  3. Singlet-paired coupled cluster theory for open shells

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    Gomez, John A.; Henderson, Thomas M.; Scuseria, Gustavo E.

    2016-06-01

    Restricted single-reference coupled cluster theory truncated to single and double excitations accurately describes weakly correlated systems, but often breaks down in the presence of static or strong correlation. Good coupled cluster energies in the presence of degeneracies can be obtained by using a symmetry-broken reference, such as unrestricted Hartree-Fock, but at the cost of good quantum numbers. A large body of work has shown that modifying the coupled cluster ansatz allows for the treatment of strong correlation within a single-reference, symmetry-adapted framework. The recently introduced singlet-paired coupled cluster doubles (CCD0) method is one such model, which recovers correct behavior for strong correlation without requiring symmetry breaking in the reference. Here, we extend singlet-paired coupled cluster for application to open shells via restricted open-shell singlet-paired coupled cluster singles and doubles (ROCCSD0). The ROCCSD0 approach retains the benefits of standard coupled cluster theory and recovers correct behavior for strongly correlated, open-shell systems using a spin-preserving ROHF reference.

  4. Singlet-paired coupled cluster theory for open shells

    International Nuclear Information System (INIS)

    Gomez, John A.; Henderson, Thomas M.; Scuseria, Gustavo E.

    2016-01-01

    Restricted single-reference coupled cluster theory truncated to single and double excitations accurately describes weakly correlated systems, but often breaks down in the presence of static or strong correlation. Good coupled cluster energies in the presence of degeneracies can be obtained by using a symmetry-broken reference, such as unrestricted Hartree-Fock, but at the cost of good quantum numbers. A large body of work has shown that modifying the coupled cluster ansatz allows for the treatment of strong correlation within a single-reference, symmetry-adapted framework. The recently introduced singlet-paired coupled cluster doubles (CCD0) method is one such model, which recovers correct behavior for strong correlation without requiring symmetry breaking in the reference. Here, we extend singlet-paired coupled cluster for application to open shells via restricted open-shell singlet-paired coupled cluster singles and doubles (ROCCSD0). The ROCCSD0 approach retains the benefits of standard coupled cluster theory and recovers correct behavior for strongly correlated, open-shell systems using a spin-preserving ROHF reference.

  5. Seniority zero pair coupled cluster doubles theory

    International Nuclear Information System (INIS)

    Stein, Tamar; Henderson, Thomas M.; Scuseria, Gustavo E.

    2014-01-01

    Coupled cluster theory with single and double excitations accurately describes weak electron correlation but is known to fail in cases of strong static correlation. Fascinatingly, however, pair coupled cluster doubles (p-CCD), a simplified version of the theory limited to pair excitations that preserve the seniority of the reference determinant (i.e., the number of unpaired electrons), has mean field computational cost and is an excellent approximation to the full configuration interaction (FCI) of the paired space provided that the orbital basis defining the pairing scheme is adequately optimized. In previous work, we have shown that optimization of the pairing scheme in the seniority zero FCI leads to a very accurate description of static correlation. The same conclusion extends to p-CCD if the orbitals are optimized to make the p-CCD energy stationary. We here demonstrate these results with numerous examples. We also explore the contributions of different seniority sectors to the coupled cluster doubles (CCD) correlation energy using different orbital bases. We consider both Hartree-Fock and Brueckner orbitals, and the role of orbital localization. We show how one can pair the orbitals so that the role of the Brueckner orbitals at the CCD level is retained at the p-CCD level. Moreover, we explore ways of extending CCD to accurately describe strongly correlated systems

  6. Quasi-planar elemental clusters in pair interactions approximation

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    Chkhartishvili Levan

    2016-01-01

    Full Text Available The pair-interactions approximation, when applied to describe elemental clusters, only takes into account bonding between neighboring atoms. According to this approach, isomers of wrapped forms of 2D clusters – nanotubular and fullerene-like structures – and truly 3D clusters, are generally expected to be more stable than their quasi-planar counterparts. This is because quasi-planar clusters contain more peripheral atoms with dangling bonds and, correspondingly, fewer atoms with saturated bonds. However, the differences in coordination numbers between central and peripheral atoms lead to the polarization of bonds. The related corrections to the molar binding energy can make small, quasi-planar clusters more stable than their 2D wrapped allotropes and 3D isomers. The present work provides a general theoretical frame for studying the relative stability of small elemental clusters within the pair interactions approximation.

  7. Asteroid clusters similar to asteroid pairs

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    Pravec, P.; Fatka, P.; Vokrouhlický, D.; Scheeres, D. J.; Kušnirák, P.; Hornoch, K.; Galád, A.; Vraštil, J.; Pray, D. P.; Krugly, Yu. N.; Gaftonyuk, N. M.; Inasaridze, R. Ya.; Ayvazian, V. R.; Kvaratskhelia, O. I.; Zhuzhunadze, V. T.; Husárik, M.; Cooney, W. R.; Gross, J.; Terrell, D.; Világi, J.; Kornoš, L.; Gajdoš, Š.; Burkhonov, O.; Ehgamberdiev, Sh. A.; Donchev, Z.; Borisov, G.; Bonev, T.; Rumyantsev, V. V.; Molotov, I. E.

    2018-04-01

    We studied the membership, size ratio and rotational properties of 13 asteroid clusters consisting of between 3 and 19 known members that are on similar heliocentric orbits. By backward integrations of their orbits, we confirmed their cluster membership and estimated times elapsed since separation of the secondaries (the smaller cluster members) from the primary (i.e., cluster age) that are between 105 and a few 106 years. We ran photometric observations for all the cluster primaries and a sample of secondaries and we derived their accurate absolute magnitudes and rotation periods. We found that 11 of the 13 clusters follow the same trend of primary rotation period vs mass ratio as asteroid pairs that was revealed by Pravec et al. (2010). We generalized the model of the post-fission system for asteroid pairs by Pravec et al. (2010) to a system of N components formed by rotational fission and we found excellent agreement between the data for the 11 asteroid clusters and the prediction from the theory of their formation by rotational fission. The two exceptions are the high-mass ratio (q > 0.7) clusters of (18777) Hobson and (22280) Mandragora for which a different formation mechanism is needed. Two candidate mechanisms for formation of more than one secondary by rotational fission were published: the secondary fission process proposed by Jacobson and Scheeres (2011) and a cratering collision event onto a nearly critically rotating primary proposed by Vokrouhlický et al. (2017). It will have to be revealed from future studies which of the clusters were formed by one or the other process. To that point, we found certain further interesting properties and features of the asteroid clusters that place constraints on the theories of their formation, among them the most intriguing being the possibility of a cascade disruption for some of the clusters.

  8. Lattice dynamics of impurity clusters : application to pairs

    International Nuclear Information System (INIS)

    Chandralekha Devi, N.; Behera, S.N.

    1979-01-01

    A general solution is obtained for the lattice dynamics of a cluster of n-impurity atoms using the double-time Green's function formalism. The cluster is characterized by n-mass defect and m-force constant change parameters. It is shown that this general solution for the Green's function for the n-impurity cluster can also be expressed in terms of the Green's function for the (n-1)-impurity cluster. As an application, the cluster impurity modes for a pair are calculated using the Debye model for the host lattice dynamics. The splitting of the high frequency local modes and nearly zero frequency resonant modes due to pairs show an oscillatory behaviour on varying the distance of separation between the two impurity atoms. These oscillations are most prominent for two similar impurities and get damped for two dissimilar impurities or if one of the impurities produces a force constant change. The predictions of the calculation provide qualitative explanation of the data obtained from the infrared measurements of the resonant modes in mixed crystal system of KBrsub(1-c)Clsub(c):Lisup(+) and KBrsub(1-c)Isub(c):Lisup(+). (author)

  9. Changing cluster composition in cluster randomised controlled trials: design and analysis considerations

    Science.gov (United States)

    2014-01-01

    Background There are many methodological challenges in the conduct and analysis of cluster randomised controlled trials, but one that has received little attention is that of post-randomisation changes to cluster composition. To illustrate this, we focus on the issue of cluster merging, considering the impact on the design, analysis and interpretation of trial outcomes. Methods We explored the effects of merging clusters on study power using standard methods of power calculation. We assessed the potential impacts on study findings of both homogeneous cluster merges (involving clusters randomised to the same arm of a trial) and heterogeneous merges (involving clusters randomised to different arms of a trial) by simulation. To determine the impact on bias and precision of treatment effect estimates, we applied standard methods of analysis to different populations under analysis. Results Cluster merging produced a systematic reduction in study power. This effect depended on the number of merges and was most pronounced when variability in cluster size was at its greatest. Simulations demonstrate that the impact on analysis was minimal when cluster merges were homogeneous, with impact on study power being balanced by a change in observed intracluster correlation coefficient (ICC). We found a decrease in study power when cluster merges were heterogeneous, and the estimate of treatment effect was attenuated. Conclusions Examples of cluster merges found in previously published reports of cluster randomised trials were typically homogeneous rather than heterogeneous. Simulations demonstrated that trial findings in such cases would be unbiased. However, simulations also showed that any heterogeneous cluster merges would introduce bias that would be hard to quantify, as well as having negative impacts on the precision of estimates obtained. Further methodological development is warranted to better determine how to analyse such trials appropriately. Interim recommendations

  10. Unequal cluster sizes in stepped-wedge cluster randomised trials: a systematic review.

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    Kristunas, Caroline; Morris, Tom; Gray, Laura

    2017-11-15

    To investigate the extent to which cluster sizes vary in stepped-wedge cluster randomised trials (SW-CRT) and whether any variability is accounted for during the sample size calculation and analysis of these trials. Any, not limited to healthcare settings. Any taking part in an SW-CRT published up to March 2016. The primary outcome is the variability in cluster sizes, measured by the coefficient of variation (CV) in cluster size. Secondary outcomes include the difference between the cluster sizes assumed during the sample size calculation and those observed during the trial, any reported variability in cluster sizes and whether the methods of sample size calculation and methods of analysis accounted for any variability in cluster sizes. Of the 101 included SW-CRTs, 48% mentioned that the included clusters were known to vary in size, yet only 13% of these accounted for this during the calculation of the sample size. However, 69% of the trials did use a method of analysis appropriate for when clusters vary in size. Full trial reports were available for 53 trials. The CV was calculated for 23 of these: the median CV was 0.41 (IQR: 0.22-0.52). Actual cluster sizes could be compared with those assumed during the sample size calculation for 14 (26%) of the trial reports; the cluster sizes were between 29% and 480% of that which had been assumed. Cluster sizes often vary in SW-CRTs. Reporting of SW-CRTs also remains suboptimal. The effect of unequal cluster sizes on the statistical power of SW-CRTs needs further exploration and methods appropriate to studies with unequal cluster sizes need to be employed. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. Analyzing survival curves at a fixed point in time for paired and clustered right-censored data

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    Su, Pei-Fang; Chi, Yunchan; Lee, Chun-Yi; Shyr, Yu; Liao, Yi-De

    2018-01-01

    In clinical trials, information about certain time points may be of interest in making decisions about treatment effectiveness. Rather than comparing entire survival curves, researchers can focus on the comparison at fixed time points that may have a clinical utility for patients. For two independent samples of right-censored data, Klein et al. (2007) compared survival probabilities at a fixed time point by studying a number of tests based on some transformations of the Kaplan-Meier estimators of the survival function. However, to compare the survival probabilities at a fixed time point for paired right-censored data or clustered right-censored data, their approach would need to be modified. In this paper, we extend the statistics to accommodate the possible within-paired correlation and within-clustered correlation, respectively. We use simulation studies to present comparative results. Finally, we illustrate the implementation of these methods using two real data sets. PMID:29456280

  12. Re-estimating sample size in cluster randomized trials with active recruitment within clusters

    NARCIS (Netherlands)

    van Schie, Sander; Moerbeek, Mirjam

    2014-01-01

    Often only a limited number of clusters can be obtained in cluster randomised trials, although many potential participants can be recruited within each cluster. Thus, active recruitment is feasible within the clusters. To obtain an efficient sample size in a cluster randomised trial, the cluster

  13. Ethical implications of excessive cluster sizes in cluster randomised trials.

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    Hemming, Karla; Taljaard, Monica; Forbes, Gordon; Eldridge, Sandra M; Weijer, Charles

    2018-02-20

    The cluster randomised trial (CRT) is commonly used in healthcare research. It is the gold-standard study design for evaluating healthcare policy interventions. A key characteristic of this design is that as more participants are included, in a fixed number of clusters, the increase in achievable power will level off. CRTs with cluster sizes that exceed the point of levelling-off will have excessive numbers of participants, even if they do not achieve nominal levels of power. Excessively large cluster sizes may have ethical implications due to exposing trial participants unnecessarily to the burdens of both participating in the trial and the potential risks of harm associated with the intervention. We explore these issues through the use of two case studies. Where data are routinely collected, available at minimum cost and the intervention poses low risk, the ethical implications of excessively large cluster sizes are likely to be low (case study 1). However, to maximise the social benefit of the study, identification of excessive cluster sizes can allow for prespecified and fully powered secondary analyses. In the second case study, while there is no burden through trial participation (because the outcome data are routinely collected and non-identifiable), the intervention might be considered to pose some indirect risk to patients and risks to the healthcare workers. In this case study it is therefore important that the inclusion of excessively large cluster sizes is justifiable on other grounds (perhaps to show sustainability). In any randomised controlled trial, including evaluations of health policy interventions, it is important to minimise the burdens and risks to participants. Funders, researchers and research ethics committees should be aware of the ethical issues of excessively large cluster sizes in cluster trials. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is

  14. Synergy between pair coupled cluster doubles and pair density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Garza, Alejandro J.; Bulik, Ireneusz W. [Department of Chemistry, Rice University, Houston, Texas 77251-1892 (United States); Henderson, Thomas M. [Department of Chemistry and Department of Physics and Astronomy, Rice University, Houston, Texas 77251-1892 (United States); Scuseria, Gustavo E. [Department of Chemistry and Department of Physics and Astronomy, Rice University, Houston, Texas 77251-1892 (United States); Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

    2015-01-28

    Pair coupled cluster doubles (pCCD) has been recently studied as a method capable of accounting for static correlation with low polynomial cost. We present three combinations of pCCD with Kohn–Sham functionals of the density and on-top pair density (the probability of finding two electrons on top of each other) to add dynamic correlation to pCCD without double counting. With a negligible increase in computational cost, these pCCD+DFT blends greatly improve upon pCCD in the description of typical problems where static and dynamic correlations are both important. We argue that—as a black-box method with low scaling, size-extensivity, size-consistency, and a simple quasidiagonal two-particle density matrix—pCCD is an excellent match for pair density functionals in this type of fusion of multireference wavefunctions with DFT.

  15. Improving elementary school quality through the use of a social-emotional and character development program: a matched-pair, cluster-randomized, controlled trial in Hawai'i.

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    Snyder, Frank J; Vuchinich, Samuel; Acock, Alan; Washburn, Isaac J; Flay, Brian R

    2012-01-01

    School safety and quality affect student learning and success. This study examined the effects of a comprehensive elementary school-wide social-emotional and character education program, Positive Action, on teacher, parent, and student perceptions of school safety and quality utilizing a matched-pair, cluster-randomized, controlled design. The Positive Action Hawai'i trial included 20 racially/ethnically diverse schools and was conducted from 2002-2003 through 2005-2006. School-level archival data, collected by the Hawai'i Department of Education, were used to examine program effects at 1-year post-trial. Teacher, parent, and student data were analyzed to examine indicators of school quality such as student safety and well-being, involvement, and satisfaction, as well as overall school quality. Matched-paired t-tests were used for the primary analysis, and sensitivity analyses included permutation tests and random-intercept growth curve models. Analyses comparing change from baseline to 1-year post-trial revealed that intervention schools demonstrated significantly improved school quality compared to control schools, with 21%, 13%, and 16% better overall school quality scores as reported by teachers, parents, and students, respectively. Teacher, parent, and student reports on individual school-quality indicators showed improvement in student safety and well-being, involvement, satisfaction, quality student support, focused and sustained action, standards-based learning, professionalism and system capacity, and coordinated team work. Teacher reports also showed an improvement in the responsiveness of the system. School quality was substantially improved, providing evidence that a school-wide social-emotional and character education program can enhance school quality and facilitate whole-school change. © 2011, American School Health Association.

  16. Clustering in surgical trials - database of intracluster correlations

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    Cook Jonathan A

    2012-01-01

    Full Text Available Abstract Background Randomised trials evaluation of surgical interventions are often designed and analysed as if the outcome of individual patients is independent of the surgeon providing the intervention. There is reason to expect outcomes for patients treated by the same surgeon tend to be more similar than those under the care of another surgeon due to previous experience, individual practice, training, and infrastructure. Such a phenomenon is referred to as the clustering effect and potentially impacts on the design and analysis adopted and thereby the required sample size. The aim of this work was to inform trial design by quantifying clustering effects (at both centre and surgeon level for various outcomes using a database of surgical trials. Methods Intracluster correlation coefficients (ICCs were calculated for outcomes from a set of 10 multicentre surgical trials for a range of outcomes and different time points for clustering at both the centre and surgeon level. Results ICCs were calculated for 198 outcomes across the 10 trials at both centre and surgeon cluster levels. The number of cases varied from 138 to 1370 across the trials. The median (range average cluster size was 32 (9 to 51 and 6 (3 to 30 for centre and surgeon levels respectively. ICC estimates varied substantially between outcome type though uncertainty around individual ICC estimates was substantial, which was reflected in generally wide confidence intervals. Conclusions This database of surgical trials provides trialists with valuable information on how to design surgical trials. Our data suggests clustering of outcome is more of an issue than has been previously acknowledged. We anticipate that over time the addition of ICCs from further surgical trial datasets to our database will further inform the design of surgical trials.

  17. Group sequential designs for stepped-wedge cluster randomised trials.

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    Grayling, Michael J; Wason, James Ms; Mander, Adrian P

    2017-10-01

    The stepped-wedge cluster randomised trial design has received substantial attention in recent years. Although various extensions to the original design have been proposed, no guidance is available on the design of stepped-wedge cluster randomised trials with interim analyses. In an individually randomised trial setting, group sequential methods can provide notable efficiency gains and ethical benefits. We address this by discussing how established group sequential methodology can be adapted for stepped-wedge designs. Utilising the error spending approach to group sequential trial design, we detail the assumptions required for the determination of stepped-wedge cluster randomised trials with interim analyses. We consider early stopping for efficacy, futility, or efficacy and futility. We describe first how this can be done for any specified linear mixed model for data analysis. We then focus on one particular commonly utilised model and, using a recently completed stepped-wedge cluster randomised trial, compare the performance of several designs with interim analyses to the classical stepped-wedge design. Finally, the performance of a quantile substitution procedure for dealing with the case of unknown variance is explored. We demonstrate that the incorporation of early stopping in stepped-wedge cluster randomised trial designs could reduce the expected sample size under the null and alternative hypotheses by up to 31% and 22%, respectively, with no cost to the trial's type-I and type-II error rates. The use of restricted error maximum likelihood estimation was found to be more important than quantile substitution for controlling the type-I error rate. The addition of interim analyses into stepped-wedge cluster randomised trials could help guard against time-consuming trials conducted on poor performing treatments and also help expedite the implementation of efficacious treatments. In future, trialists should consider incorporating early stopping of some kind into

  18. Childhood asthma clusters and response to therapy in clinical trials.

    Science.gov (United States)

    Chang, Timothy S; Lemanske, Robert F; Mauger, David T; Fitzpatrick, Anne M; Sorkness, Christine A; Szefler, Stanley J; Gangnon, Ronald E; Page, C David; Jackson, Daniel J

    2014-02-01

    Childhood asthma clusters, or subclasses, have been developed by computational methods without evaluation of clinical utility. To replicate and determine whether childhood asthma clusters previously identified computationally in the Severe Asthma Research Program (SARP) are associated with treatment responses in Childhood Asthma Research and Education (CARE) Network clinical trials. A cluster assignment model was determined by using SARP participant data. A total of 611 participants 6 to 18 years old from 3 CARE trials were assigned to SARP pediatric clusters. Primary and secondary outcomes were analyzed by cluster in each trial. CARE participants were assigned to SARP clusters with high accuracy. Baseline characteristics were similar between SARP and CARE children of the same cluster. Treatment response in CARE trials was generally similar across clusters. However, with the caveat of a smaller sample size, children in the early-onset/severe-lung function cluster had best response with fluticasone/salmeterol (64% vs 23% 2.5× fluticasone and 13% fluticasone/montelukast in the Best ADd-on Therapy Giving Effective Responses trial; P = .011) and children in the early-onset/comorbidity cluster had the least clinical efficacy to treatments (eg, -0.076% change in FEV1 in the Characterizing Response to Leukotriene Receptor Antagonist and Inhaled Corticosteroid trial). In this study, we replicated SARP pediatric asthma clusters by using a separate, large clinical trials network. Early-onset/severe-lung function and early-onset/comorbidity clusters were associated with differential and limited response to therapy, respectively. Further prospective study of therapeutic response by cluster could provide new insights into childhood asthma treatment. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  19. Reporting non-adherence in cluster randomised trials: A systematic review.

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    Agbla, Schadrac C; DiazOrdaz, Karla

    2018-06-01

    Treatment non-adherence in randomised trials refers to situations where some participants do not receive their allocated treatment as intended. For cluster randomised trials, where the unit of randomisation is a group of participants, non-adherence may occur at the cluster or individual level. When non-adherence occurs, randomisation no longer guarantees that the relationship between treatment receipt and outcome is unconfounded, and the power to detect the treatment effects in intention-to-treat analysis may be reduced. Thus, recording adherence and estimating the causal treatment effect adequately are of interest for clinical trials. To assess the extent of reporting of non-adherence issues in published cluster trials and to establish which methods are currently being used for addressing non-adherence, if any, and whether clustering is accounted for in these. We systematically reviewed 132 cluster trials published in English in 2011 previously identified through a search in PubMed. One-hundred and twenty three cluster trials were included in this systematic review. Non-adherence was reported in 56 cluster trials. Among these, 19 reported a treatment efficacy estimate: per protocol in 15 and as treated in 4. No study discussed the assumptions made by these methods, their plausibility or the sensitivity of the results to deviations from these assumptions. The year of publication of the cluster trials included in this review (2011) could be considered a limitation of this study; however, no new guidelines regarding the reporting and the handling of non-adherence for cluster trials have been published since. In addition, a single reviewer undertook the data extraction. To mitigate this, a second reviewer conducted a validation of the extraction process on 15 randomly selected reports. Agreement was satisfactory (93%). Despite the recommendations of the Consolidated Standards of Reporting Trials statement extension to cluster randomised trials, treatment adherence is

  20. On the use of big-bang method to generate low-energy structures of atomic clusters modeled with pair potentials of different ranges.

    Science.gov (United States)

    Marques, J M C; Pais, A A C C; Abreu, P E

    2012-02-05

    The efficiency of the so-called big-bang method for the optimization of atomic clusters is analysed in detail for Morse pair potentials with different ranges; here, we have used Morse potentials with four different ranges, from long- ρ = 3) to short-ranged ρ = 14) interactions. Specifically, we study the efficacy of the method in discovering low-energy structures, including the putative global minimum, as a function of the potential range and the cluster size. A new global minimum structure for long-ranged ρ = 3) Morse potential at the cluster size of n= 240 is reported. The present results are useful to assess the maximum cluster size for each type of interaction where the global minimum can be discovered with a limited number of big-bang trials. Copyright © 2011 Wiley Periodicals, Inc.

  1. Morphologies and ages of star cluster pairs and multiplets in the Small Magellanic Cloud

    Science.gov (United States)

    de Oliveira, M. R.; Dutra, C. M.; Bica, E.; Dottori, H.

    2000-10-01

    An isophotal atlas of 75 star cluster pairs and multiplets in the Small Magellanic Cloud is presented, comprising 176 objects. They are concentrated in the SMC main body. The isophotal contours were made from Digitized Sky Survey* images and showed relevant structural features possibly related to interactions in about 25% of the sample. Previous N-body simulations indicate that such shapes could be due to tidal tails, bridges or common envelopes. The diameter ratio between the members of a pair is preferentially in the range 1 - 2, with a peak at 1. The projected separation is in the range ~ 3 - 22 pc with a pronounced peak at ~ 13 pc. For 91 objects it was possible to derive ages from Colour-Magnitude Diagrams using the OGLE-II photometric survey. The cluster multiplets in general occur in OB stellar associations and/or HII region complexes. This indicates a common origin and suggests that multiplets coalesce into pairs or single clusters in a short time scale. Pairs in the SMC appear to be mostly coeval and consequently captures are a rare phenomenon. We find evidence that star cluster pairs and multiplets may have had an important role in the dynamical history of clusters presently seen as large single objects. The images in this study are based on photographic data obtained using the UK Schmidt Telescope, which was operated by the Royal Observatory Edinburgh, with funding from the UK Science and Engineering Research Council, until 1988 June, and thereafter by the Anglo-Australian Observatory. Original plate material is copyright by the Royal Observatory Edinburgh and the Anglo-Australian Observatory. The plates were processed into the present compressed digital form with their permission. The Digitized Sky Survey was produced at the Space Telescope Science Institute under US Government grant NAG W-2166.

  2. Active Play in After-school Programmes: development of an intervention and description of a matched-pair cluster-randomised trial assessing physical activity play in after-school programmes.

    Science.gov (United States)

    Riiser, Kirsti; Helseth, Sølvi; Ellingsen, Hanna; Fallang, Bjørg; Løndal, Knut

    2017-08-04

    Interventions delivered in after-school programmes (ASPs) have the potential to become a means of ensuring adequate physical activity among schoolchildren. This requires a motivational climate, allowing for self-determined play. If trained, ASP staff may represent a valuable resource for supporting such play. Increasing knowledge and supportive skills among ASP staff may also potentially increase their motivation for work. The purpose of this article is to describe the development of the 'Active Play in ASP' intervention, which aims to promote physical activity among first graders attending ASP, and to present a protocol for a matched-pair cluster-randomised trial to evaluate the intervention. Informed by experiences from practice, evidence-based knowledge and theory, the intervention was developed in a stepwise process including focus group meetings and a small-scale pilot test. The intervention contains a course programme for ASP staff to increase their skills in how to support physical activity through play. In a cluster randomised controlled trial, the ASPs will be matched and randomly allocated to receive the 7-month intervention or to a control group. Outcomes will be assessed at baseline, after 7 and 19 months. First graders attending the ASPs included are eligible. The primary outcome will be accelerometer-determined minutes in moderate to vigorous physical activity in the ASP. The study uses a mixed methods approach including observations and interviews to provide rich descriptions of the concept of children's physical activity in ASP. Moreover, the trial will assess whether the ASP staff benefits from participation in the intervention in terms of increased work motivation. Lastly, process evaluations of programme fidelity, satisfaction and suggestions on improvement will be performed. The study is approved by the Data Protection Official for Research (reference no 46008). Results will be presented in conferences and peer-reviewed journals. Clinical Trials

  3. Effectiveness of advance care planning with family carers in dementia nursing homes: A paired cluster randomized controlled trial.

    Science.gov (United States)

    Brazil, Kevin; Carter, Gillian; Cardwell, Chris; Clarke, Mike; Hudson, Peter; Froggatt, Katherine; McLaughlin, Dorry; Passmore, Peter; Kernohan, W George

    2018-03-01

    In dementia care, a large number of treatment decisions are made by family carers on behalf of their family member who lacks decisional capacity; advance care planning can support such carers in the decision-making of care goals. However, given the relative importance of advance care planning in dementia care, the prevalence of advance care planning in dementia care is poor. To evaluate the effectiveness of advance care planning with family carers in dementia care homes. Paired cluster randomized controlled trial. The intervention comprised a trained facilitator, family education, family meetings, documentation of advance care planning decisions and intervention orientation for general practitioners and nursing home staff. A total of 24 nursing homes with a dementia nursing category located in Northern Ireland, United Kingdom. Family carers of nursing home residents classified as having dementia and judged as not having decisional capacity to participate in advance care planning discussions. The primary outcome was family carer uncertainty in decision-making about the care of the resident (Decisional Conflict Scale). There was evidence of a reduction in total Decisional Conflict Scale score in the intervention group compared with the usual care group (-10.5, 95% confidence interval: -16.4 to -4.7; p planning was effective in reducing family carer uncertainty in decision-making concerning the care of their family member and improving perceptions of quality of care in nursing homes. Given the global significance of dementia, the implications for clinicians and policy makers include them recognizing the importance of family carer education and improving communication between family carers and formal care providers.

  4. Impact of a social-emotional and character development program on school-level indicators of academic achievement, absenteeism, and disciplinary outcomes: A matched-pair, cluster randomized, controlled trial.

    Science.gov (United States)

    Snyder, Frank; Flay, Brian; Vuchinich, Samuel; Acock, Alan; Washburn, Isaac; Beets, Michael; Li, Kin-Kit

    2010-01-01

    This paper reports the effects of a comprehensive elementary school-based social-emotional and character education program on school-level achievement, absenteeism, and disciplinary outcomes utilizing a matched-pair, cluster randomized, controlled design. The Positive Action Hawai'i trial included 20 racially/ethnically diverse schools (mean enrollment = 544) and was conducted from the 2002-03 through the 2005-06 academic years. Using school-level archival data, analyses comparing change from baseline (2002) to one-year post trial (2007) revealed that intervention schools scored 9.8% better on the TerraNova (2 nd ed.) test for reading and 8.8% on math; 20.7% better in Hawai'i Content and Performance Standards scores for reading and 51.4% better in math; and that intervention schools reported 15.2% lower absenteeism and fewer suspensions (72.6%) and retentions (72.7%). Overall, effect sizes were moderate to large (range 0.5-1.1) for all of the examined outcomes. Sensitivity analyses using permutation models and random-intercept growth curve models substantiated results. The results provide evidence that a comprehensive school-based program, specifically developed to target student behavior and character, can positively influence school-level achievement, attendance, and disciplinary outcomes concurrently.

  5. A systematic review of the usage of flow diagram in cluster randomized trials

    Directory of Open Access Journals (Sweden)

    Kostić M.

    2014-01-01

    Full Text Available Flow diagram represent an integral part of consolidated standards of reporting trials (CONSORT. Its use in reporting cluster randomization trials is highly recommended. The aim of this article is to present frequency of the use of flow diagram in cluster randomized trials in accordance with standards of reporting. The team has researched Medline database and singled-out 474 studies with cluster randomization for analysis. The studies were reviewed to identify the use of graphic representation, compliance with standards of reporting and the date when study was published. Depending from its duration, studies were divided on completed, and those still ongoing. Usage of CONSORT is recorded in 145 (31% literature units. Frequency of flow diagram was statistically much higher in studies which were in compliance with standards (86,2%, in comparison to those which did not use CONSORT guidelines (71,4%, as well as in completed studies (81,2% in comparison to pilot project studies (54,3%. Number of cluster randomized trials gathered through MEDLINE's search of key words 'cluster randomized trial [ti]' and 'cluster randomised trial [ti]', as well as the use of CONSORT in the reports of cluster randomized trials, are showing linear growth over time (p<0,001. Frequency of flow diagram is higher in the reports of cluster randomized trials that were done in accordance with the standards of reporting.

  6. Unveiling clusters of RNA transcript pairs associated with markers of Alzheimer's disease progression.

    Directory of Open Access Journals (Sweden)

    Ahmed Shamsul Arefin

    Full Text Available BACKGROUND: One primary goal of transcriptomic studies is identifying gene expression patterns correlating with disease progression. This is usually achieved by considering transcripts that independently pass an arbitrary threshold (e.g. p<0.05. In diseases involving severe perturbations of multiple molecular systems, such as Alzheimer's disease (AD, this univariate approach often results in a large list of seemingly unrelated transcripts. We utilised a powerful multivariate clustering approach to identify clusters of RNA biomarkers strongly associated with markers of AD progression. We discuss the value of considering pairs of transcripts which, in contrast to individual transcripts, helps avoid natural human transcriptome variation that can overshadow disease-related changes. METHODOLOGY/PRINCIPAL FINDINGS: We re-analysed a dataset of hippocampal transcript levels in nine controls and 22 patients with varying degrees of AD. A large-scale clustering approach determined groups of transcript probe sets that correlate strongly with measures of AD progression, including both clinical and neuropathological measures and quantifiers of the characteristic transcriptome shift from control to severe AD. This enabled identification of restricted groups of highly correlated probe sets from an initial list of 1,372 previously published by our group. We repeated this analysis on an expanded dataset that included all pair-wise combinations of the 1,372 probe sets. As clustering of this massive dataset is unfeasible using standard computational tools, we adapted and re-implemented a clustering algorithm that uses external memory algorithmic approach. This identified various pairs that strongly correlated with markers of AD progression and highlighted important biological pathways potentially involved in AD pathogenesis. CONCLUSIONS/SIGNIFICANCE: Our analyses demonstrate that, although there exists a relatively large molecular signature of AD progression, only

  7. Relative efficiency and sample size for cluster randomized trials with variable cluster sizes.

    Science.gov (United States)

    You, Zhiying; Williams, O Dale; Aban, Inmaculada; Kabagambe, Edmond Kato; Tiwari, Hemant K; Cutter, Gary

    2011-02-01

    The statistical power of cluster randomized trials depends on two sample size components, the number of clusters per group and the numbers of individuals within clusters (cluster size). Variable cluster sizes are common and this variation alone may have significant impact on study power. Previous approaches have taken this into account by either adjusting total sample size using a designated design effect or adjusting the number of clusters according to an assessment of the relative efficiency of unequal versus equal cluster sizes. This article defines a relative efficiency of unequal versus equal cluster sizes using noncentrality parameters, investigates properties of this measure, and proposes an approach for adjusting the required sample size accordingly. We focus on comparing two groups with normally distributed outcomes using t-test, and use the noncentrality parameter to define the relative efficiency of unequal versus equal cluster sizes and show that statistical power depends only on this parameter for a given number of clusters. We calculate the sample size required for an unequal cluster sizes trial to have the same power as one with equal cluster sizes. Relative efficiency based on the noncentrality parameter is straightforward to calculate and easy to interpret. It connects the required mean cluster size directly to the required sample size with equal cluster sizes. Consequently, our approach first determines the sample size requirements with equal cluster sizes for a pre-specified study power and then calculates the required mean cluster size while keeping the number of clusters unchanged. Our approach allows adjustment in mean cluster size alone or simultaneous adjustment in mean cluster size and number of clusters, and is a flexible alternative to and a useful complement to existing methods. Comparison indicated that we have defined a relative efficiency that is greater than the relative efficiency in the literature under some conditions. Our measure

  8. Person mobility in the design and analysis of cluster-randomized cohort prevention trials.

    Science.gov (United States)

    Vuchinich, Sam; Flay, Brian R; Aber, Lawrence; Bickman, Leonard

    2012-06-01

    Person mobility is an inescapable fact of life for most cluster-randomized (e.g., schools, hospitals, clinic, cities, state) cohort prevention trials. Mobility rates are an important substantive consideration in estimating the effects of an intervention. In cluster-randomized trials, mobility rates are often correlated with ethnicity, poverty and other variables associated with disparity. This raises the possibility that estimated intervention effects may generalize to only the least mobile segments of a population and, thus, create a threat to external validity. Such mobility can also create threats to the internal validity of conclusions from randomized trials. Researchers must decide how to deal with persons who leave study clusters during a trial (dropouts), persons and clusters that do not comply with an assigned intervention, and persons who enter clusters during a trial (late entrants), in addition to the persons who remain for the duration of a trial (stayers). Statistical techniques alone cannot solve the key issues of internal and external validity raised by the phenomenon of person mobility. This commentary presents a systematic, Campbellian-type analysis of person mobility in cluster-randomized cohort prevention trials. It describes four approaches for dealing with dropouts, late entrants and stayers with respect to data collection, analysis and generalizability. The questions at issue are: 1) From whom should data be collected at each wave of data collection? 2) Which cases should be included in the analyses of an intervention effect? and 3) To what populations can trial results be generalized? The conclusions lead to recommendations for the design and analysis of future cluster-randomized cohort prevention trials.

  9. Impact of a cancer clinical trials web site on discussions about trial participation: a cluster randomized trial.

    Science.gov (United States)

    Dear, R F; Barratt, A L; Askie, L M; Butow, P N; McGeechan, K; Crossing, S; Currow, D C; Tattersall, M H N

    2012-07-01

    Cancer patients want access to reliable information about currently recruiting clinical trials. Oncologists and their patients were randomly assigned to access a consumer-friendly cancer clinical trials web site [Australian Cancer Trials (ACT), www.australiancancertrials.gov.au] or to usual care in a cluster randomized controlled trial. The primary outcome, measured from audio recordings of oncologist-patient consultations, was the proportion of patients with whom participation in any clinical trial was discussed. Analysis was by intention-to-treat accounting for clustering and stratification. Thirty medical oncologists and 493 patients were recruited. Overall, 46% of consultations in the intervention group compared with 34% in the control group contained a discussion about clinical trials (P=0.08). The mean consultation length in both groups was 29 min (P=0.69). The proportion consenting to a trial was 10% in both groups (P=0.65). Patients' knowledge about randomized trials was lower in the intervention than the control group (mean score 3.0 versus 3.3, P=0.03) but decisional conflict scores were similar (mean score 42 versus 43, P=0.83). Good communication between patients and physicians is essential. Within this context, a web site such as Australian Cancer Trials may be an important tool to encourage discussion about clinical trial participation.

  10. Effects of cluster-shell competition and BCS-like pairing in 12C

    Science.gov (United States)

    Matsuno, H.; Itagaki, N.

    2017-12-01

    The antisymmetrized quasi-cluster model (AQCM) was proposed to describe α-cluster and jj-coupling shell models on the same footing. In this model, the cluster-shell transition is characterized by two parameters, R representing the distance between α clusters and Λ describing the breaking of α clusters, and the contribution of the spin-orbit interaction, very important in the jj-coupling shell model, can be taken into account starting with the α-cluster model wave function. Not only the closure configurations of the major shells but also the subclosure configurations of the jj-coupling shell model can be described starting with the α-cluster model wave functions; however, the particle-hole excitations of single particles have not been fully established yet. In this study we show that the framework of AQCM can be extended even to the states with the character of single-particle excitations. For ^{12}C, two-particle-two-hole (2p2h) excitations from the subclosure configuration of 0p_{3/2} corresponding to a BCS-like pairing are described, and these shell model states are coupled with the three α-cluster model wave functions. The correlation energy from the optimal configuration can be estimated not only in the cluster part but also in the shell model part. We try to pave the way to establish a generalized description of the nuclear structure.

  11. Missing continuous outcomes under covariate dependent missingness in cluster randomised trials.

    Science.gov (United States)

    Hossain, Anower; Diaz-Ordaz, Karla; Bartlett, Jonathan W

    2017-06-01

    Attrition is a common occurrence in cluster randomised trials which leads to missing outcome data. Two approaches for analysing such trials are cluster-level analysis and individual-level analysis. This paper compares the performance of unadjusted cluster-level analysis, baseline covariate adjusted cluster-level analysis and linear mixed model analysis, under baseline covariate dependent missingness in continuous outcomes, in terms of bias, average estimated standard error and coverage probability. The methods of complete records analysis and multiple imputation are used to handle the missing outcome data. We considered four scenarios, with the missingness mechanism and baseline covariate effect on outcome either the same or different between intervention groups. We show that both unadjusted cluster-level analysis and baseline covariate adjusted cluster-level analysis give unbiased estimates of the intervention effect only if both intervention groups have the same missingness mechanisms and there is no interaction between baseline covariate and intervention group. Linear mixed model and multiple imputation give unbiased estimates under all four considered scenarios, provided that an interaction of intervention and baseline covariate is included in the model when appropriate. Cluster mean imputation has been proposed as a valid approach for handling missing outcomes in cluster randomised trials. We show that cluster mean imputation only gives unbiased estimates when missingness mechanism is the same between the intervention groups and there is no interaction between baseline covariate and intervention group. Multiple imputation shows overcoverage for small number of clusters in each intervention group.

  12. Cluster pair correlation function of simple fluids: energetic connectivity criteria

    OpenAIRE

    Pugnaloni, Luis A.; Zarragoicoechea, Guillermo J.; Vericat, Fernando

    2006-01-01

    We consider the clustering of Lennard-Jones particles by using an energetic connectivity criterion proposed long ago by T.L. Hill [J. Chem. Phys. 32, 617 (1955)] for the bond between pairs of particles. The criterion establishes that two particles are bonded (directly connected) if their relative kinetic energy is less than minus their relative potential energy. Thus, in general, it depends on the direction as well as on the magnitude of the velocities and positions of the particles. An integ...

  13. Changing ionization conditions in SDSS galaxies with active galactic nuclei as a function of environment from pairs to clusters

    International Nuclear Information System (INIS)

    Khabiboulline, Emil T.; Steinhardt, Charles L.; Silverman, John D.; Ellison, Sara L.; Mendel, J. Trevor; Patton, David R.

    2014-01-01

    We study how active galactic nucleus (AGN) activity changes across environments from galaxy pairs to clusters using 143,843 galaxies with z < 0.2 from the Sloan Digital Sky Survey. Using a refined technique, we apply a continuous measure of AGN activity, characteristic of the ionization state of the narrow-line emitting gas. Changes in key emission-line ratios ([N II] λ6548/Hα, [O III] λ5007/Hβ) between different samples allow us to disentangle different environmental effects while removing contamination. We confirm that galaxy interactions enhance AGN activity. However, conditions in the central regions of clusters are inhospitable for AGN activity even if galaxies are in pairs. These results can be explained through models of gas dynamics in which pair interactions stimulate the transfer of gas to the nucleus and clusters suppress gas availability for accretion onto the central black hole.

  14. Changing ionization conditions in SDSS galaxies with active galactic nuclei as a function of environment from pairs to clusters

    Energy Technology Data Exchange (ETDEWEB)

    Khabiboulline, Emil T.; Steinhardt, Charles L. [California Institute of Technology, 1200 East-California Boulevard, Pasadena, CA 91125 (United States); Silverman, John D. [Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa-Shi, Chiba 277-8583 (Japan); Ellison, Sara L. [Department of Physics and Astronomy, University of Victoria, Finnerty Road, Victoria, British Columbia, V8P 1A1 (Canada); Mendel, J. Trevor [Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, D-85748 Garching (Germany); Patton, David R., E-mail: ekhabibo@caltech.edu [Department of Physics and Astronomy, Trent University, 1600 West Bank Drive, Peterborough, Ontario, K9J 7B8 (Canada)

    2014-11-01

    We study how active galactic nucleus (AGN) activity changes across environments from galaxy pairs to clusters using 143,843 galaxies with z < 0.2 from the Sloan Digital Sky Survey. Using a refined technique, we apply a continuous measure of AGN activity, characteristic of the ionization state of the narrow-line emitting gas. Changes in key emission-line ratios ([N II] λ6548/Hα, [O III] λ5007/Hβ) between different samples allow us to disentangle different environmental effects while removing contamination. We confirm that galaxy interactions enhance AGN activity. However, conditions in the central regions of clusters are inhospitable for AGN activity even if galaxies are in pairs. These results can be explained through models of gas dynamics in which pair interactions stimulate the transfer of gas to the nucleus and clusters suppress gas availability for accretion onto the central black hole.

  15. Evaluation of cluster-randomized trials on maternal and child health research in developing countries

    DEFF Research Database (Denmark)

    Handlos, Line Neerup; Chakraborty, Hrishikesh; Sen, Pranab Kumar

    2009-01-01

    To summarize and evaluate all publications including cluster-randomized trials used for maternal and child health research in developing countries during the last 10 years. METHODS: All cluster-randomized trials published between 1998 and 2008 were reviewed, and those that met our criteria...... for inclusion were evaluated further. The criteria for inclusion were that the trial should have been conducted in maternal and child health care in a developing country and that the conclusions should have been made on an individual level. Methods of accounting for clustering in design and analysis were......, and the trials generally improved in quality. CONCLUSIONS: Shortcomings exist in the sample-size calculations and in the analysis of cluster-randomized trials conducted during maternal and child health research in developing countries. Even though there has been improvement over time, further progress in the way...

  16. Remote sensing of a NTC radio source from a Cluster tilted spacecraft pair

    Directory of Open Access Journals (Sweden)

    P. M. E. Décréau

    2013-11-01

    Full Text Available The Cluster mission operated a "tilt campaign" during the month of May 2008. Two of the four identical Cluster spacecraft were placed at a close distance (~50 km from each other and the spin axis of one of the spacecraft pair was tilted by an angle of ~46°. This gave the opportunity, for the first time in space, to measure global characteristics of AC electric field, at the sensitivity available with long boom (88 m antennas, simultaneously from the specific configuration of the tilted pair of satellites and from the available base of three satellites placed at a large characteristic separation (~1 RE. This paper describes how global characteristics of radio waves, in this case the configuration of the electric field polarization ellipse in 3-D-space, are identified from in situ measurements of spin modulation features by the tilted pair, validating a novel experimental concept. In the event selected for analysis, non-thermal continuum (NTC waves in the 15–25 kHz frequency range are observed from the Cluster constellation placed above the polar cap. The observed intensity variations with spin angle are those of plane waves, with an electric field polarization close to circular, at an ellipticity ratio e = 0.87. We derive the source position in 3-D by two different methods. The first one uses ray path orientation (measured by the tilted pair combined with spectral signature of magnetic field magnitude at source. The second one is obtained via triangulation from the three spacecraft baseline, using estimation of directivity angles under assumption of circular polarization. The two results are not compatible, placing sources widely apart. We present a general study of the level of systematic errors due to the assumption of circular polarization, linked to the second approach, and show how this approach can lead to poor triangulation and wrong source positioning. The estimation derived from the first method places the NTC source region in the

  17. Comparing cluster-level dynamic treatment regimens using sequential, multiple assignment, randomized trials: Regression estimation and sample size considerations.

    Science.gov (United States)

    NeCamp, Timothy; Kilbourne, Amy; Almirall, Daniel

    2017-08-01

    Cluster-level dynamic treatment regimens can be used to guide sequential treatment decision-making at the cluster level in order to improve outcomes at the individual or patient-level. In a cluster-level dynamic treatment regimen, the treatment is potentially adapted and re-adapted over time based on changes in the cluster that could be impacted by prior intervention, including aggregate measures of the individuals or patients that compose it. Cluster-randomized sequential multiple assignment randomized trials can be used to answer multiple open questions preventing scientists from developing high-quality cluster-level dynamic treatment regimens. In a cluster-randomized sequential multiple assignment randomized trial, sequential randomizations occur at the cluster level and outcomes are observed at the individual level. This manuscript makes two contributions to the design and analysis of cluster-randomized sequential multiple assignment randomized trials. First, a weighted least squares regression approach is proposed for comparing the mean of a patient-level outcome between the cluster-level dynamic treatment regimens embedded in a sequential multiple assignment randomized trial. The regression approach facilitates the use of baseline covariates which is often critical in the analysis of cluster-level trials. Second, sample size calculators are derived for two common cluster-randomized sequential multiple assignment randomized trial designs for use when the primary aim is a between-dynamic treatment regimen comparison of the mean of a continuous patient-level outcome. The methods are motivated by the Adaptive Implementation of Effective Programs Trial which is, to our knowledge, the first-ever cluster-randomized sequential multiple assignment randomized trial in psychiatry.

  18. Complementary feeding: a Global Network cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Pasha Omrana

    2011-01-01

    Full Text Available Abstract Background Inadequate and inappropriate complementary feeding are major factors contributing to excess morbidity and mortality in young children in low resource settings. Animal source foods in particular are cited as essential to achieve micronutrient requirements. The efficacy of the recommendation for regular meat consumption, however, has not been systematically evaluated. Methods/Design A cluster randomized efficacy trial was designed to test the hypothesis that 12 months of daily intake of beef added as a complementary food would result in greater linear growth velocity than a micronutrient fortified equi-caloric rice-soy cereal supplement. The study is being conducted in 4 sites of the Global Network for Women's and Children's Health Research located in Guatemala, Pakistan, Democratic Republic of the Congo (DRC and Zambia in communities with toddler stunting rates of at least 20%. Five clusters per country were randomized to each of the food arms, with 30 infants in each cluster. The daily meat or cereal supplement was delivered to the home by community coordinators, starting when the infants were 6 months of age and continuing through 18 months. All participating mothers received nutrition education messages to enhance complementary feeding practices delivered by study coordinators and through posters at the local health center. Outcome measures, obtained at 6, 9, 12, and 18 months by a separate assessment team, included anthropometry; dietary variety and diversity scores; biomarkers of iron, zinc and Vitamin B12 status (18 months; neurocognitive development (12 and 18 months; and incidence of infectious morbidity throughout the trial. The trial was supervised by a trial steering committee, and an independent data monitoring committee provided oversight for the safety and conduct of the trial. Discussion Findings from this trial will test the efficacy of daily intake of meat commencing at age 6 months and, if beneficial, will

  19. Effects of patient safety culture interventions on incident reporting in general practice : A cluster randomised trial a cluster randomised trial

    NARCIS (Netherlands)

    Verbakel, Natasha J.; Langelaan, Maaike; Verheij, Theo J M; Wagner, Cordula; Zwart, Dorien L M

    2015-01-01

    Background: A constructive safety culture is essential for the successful implementation of patient safety improvements. Aim: To assess the effect of two patient safety culture interventions on incident reporting as a proxy of safety culture. Design and setting: A three-arm cluster randomised trial

  20. Exploring the transparency mechanism and evaluating the effect of public reporting on prescription: a protocol for a cluster randomized controlled trial.

    Science.gov (United States)

    Du, Xin; Wang, Dan; Wang, Xuan; Yang, Shiru; Zhang, Xinping

    2015-03-21

    The public reporting of health outcomes has become one of the most popular topics and is accepted as a quality improvement method in the healthcare field. However, little research has been conducted on the transparency mechanism, and results are mixed with regard to the evaluation of the effect of public reporting on quality improvement. The objectives of this trial are to investigate the transparency mechanism and to evaluate the effect of public reporting on prescription at the level of individual participants. This study involves a cluster randomized controlled trial conducted in 20 primary-care facilities (clusters). Eligible clusters are those facilities with excellent hospital information systems and that have agreed to participate in the trial. The 20 clusters are matched into 10 pairs according to Technique for Order Preference by Similarity to Ideal Solution score. As the unit of randomization, each pair of facilities is assigned at random to a control or an intervention group through coin flipping. Prescribed ranking information is publicly reported in the intervention group. The public materials include the posters of individuals and of facilities, the ranking lists of general practitioners, and brochures of patients, which are updated monthly. The intervention began on 13th November 2013 and lasted for one year. Specifically, participants are surveyed at five points in time (baseline, quarterly following the intervention) through questionnaires, interviews, and observations. These participants include an average of 600 patients, 300 general practitioners, 15 directors, and 6 health bureau administrators. The primary outcomes are the transparency mechanism model and the changes in medicine-prescribe. Subsequently, the modifications in the transparency mechanism constructs are evaluated. The outcomes are measured at the individual participant level, and the professional who analyzes the data is blind to the randomization status. This study protocol

  1. Sample size adjustments for varying cluster sizes in cluster randomized trials with binary outcomes analyzed with second-order PQL mixed logistic regression.

    Science.gov (United States)

    Candel, Math J J M; Van Breukelen, Gerard J P

    2010-06-30

    Adjustments of sample size formulas are given for varying cluster sizes in cluster randomized trials with a binary outcome when testing the treatment effect with mixed effects logistic regression using second-order penalized quasi-likelihood estimation (PQL). Starting from first-order marginal quasi-likelihood (MQL) estimation of the treatment effect, the asymptotic relative efficiency of unequal versus equal cluster sizes is derived. A Monte Carlo simulation study shows this asymptotic relative efficiency to be rather accurate for realistic sample sizes, when employing second-order PQL. An approximate, simpler formula is presented to estimate the efficiency loss due to varying cluster sizes when planning a trial. In many cases sampling 14 per cent more clusters is sufficient to repair the efficiency loss due to varying cluster sizes. Since current closed-form formulas for sample size calculation are based on first-order MQL, planning a trial also requires a conversion factor to obtain the variance of the second-order PQL estimator. In a second Monte Carlo study, this conversion factor turned out to be 1.25 at most. (c) 2010 John Wiley & Sons, Ltd.

  2. Higgs pair production: choosing benchmarks with cluster analysis

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Alexandra; Dall’Osso, Martino; Dorigo, Tommaso [Dipartimento di Fisica e Astronomia and INFN, Sezione di Padova,Via Marzolo 8, I-35131 Padova (Italy); Goertz, Florian [CERN,1211 Geneva 23 (Switzerland); Gottardo, Carlo A. [Physikalisches Institut, Universität Bonn,Nussallee 12, 53115 Bonn (Germany); Tosi, Mia [CERN,1211 Geneva 23 (Switzerland)

    2016-04-20

    New physics theories often depend on a large number of free parameters. The phenomenology they predict for fundamental physics processes is in some cases drastically affected by the precise value of those free parameters, while in other cases is left basically invariant at the level of detail experimentally accessible. When designing a strategy for the analysis of experimental data in the search for a signal predicted by a new physics model, it appears advantageous to categorize the parameter space describing the model according to the corresponding kinematical features of the final state. A multi-dimensional test statistic can be used to gauge the degree of similarity in the kinematics predicted by different models; a clustering algorithm using that metric may allow the division of the space into homogeneous regions, each of which can be successfully represented by a benchmark point. Searches targeting those benchmarks are then guaranteed to be sensitive to a large area of the parameter space. In this document we show a practical implementation of the above strategy for the study of non-resonant production of Higgs boson pairs in the context of extensions of the standard model with anomalous couplings of the Higgs bosons. A non-standard value of those couplings may significantly enhance the Higgs boson pair-production cross section, such that the process could be detectable with the data that the LHC will collect in Run 2.

  3. A cluster-randomised intervention trial against Schistosoma japonicum in the Peoples' Republic of China: bovine and human transmission.

    Directory of Open Access Journals (Sweden)

    Darren J Gray

    2009-06-01

    Full Text Available Zoonotic schistosomiasis japonica is a major public health problem in China. Bovines, particularly water buffaloes, are thought to play a major role in the transmission of schistosomiasis to humans in China. Preliminary results (1998-2003 of a praziquantel (PZQ-based pilot intervention study we undertook provided proof of principle that water buffaloes are major reservoir hosts for S. japonicum in the Poyang Lake region, Jiangxi Province.Here we present the results of a cluster-randomised intervention trial (2004-2007 undertaken in Hunan and Jiangxi Provinces, with increased power and more general applicability to the lake and marshlands regions of southern China. The trial involved four matched pairs of villages with one village within each pair randomly selected as a control (human PZQ treatment only, leaving the other as the intervention (human and bovine PZQ treatment. A sentinel cohort of people to be monitored for new infections for the duration of the study was selected from each village. Results showed that combined human and bovine chemotherapy with PZQ had a greater effect on human incidence than human PZQ treatment alone.The results from this study, supported by previous experimental evidence, confirms that bovines are the major reservoir host of human schistosomiasis in the lake and marshland regions of southern China, and reinforce the rationale for the development and deployment of a transmission blocking anti-S. japonicum vaccine targeting bovines.Australian New Zealand Clinical Trials Registry ACTRN12609000263291.

  4. Complexes of DNA bases and Watson-Crick base pairs with small neutral gold clusters.

    Science.gov (United States)

    Kryachko, E S; Remacle, F

    2005-12-08

    The nature of the DNA-gold interaction determines and differentiates the affinity of the nucleobases (adenine, thymine, guanine, and cytosine) to gold. Our preliminary computational study [Kryachko, E. S.; Remacle, F. Nano Lett. 2005, 5, 735] demonstrates that two major bonding factors govern this interaction: the anchoring, either of the Au-N or Au-O type, and the nonconventional N-H...Au hydrogen bonding. In this paper, we offer insight into the nature of nucleobase-gold interactions and provide a detailed characterization of their different facets, i.e., geometrical, energetic, and spectroscopic aspects; the gold cluster size and gold coordination effects; proton affinity; and deprotonation energy. We then investigate how the Watson-Crick DNA pairing patterns are modulated by the nucleobase-gold interaction. We do so in terms of the proton affinities and deprotonation energies of those proton acceptors and proton donors which are involved in the interbase hydrogen bondings. A variety of properties of the most stable Watson-Crick [A x T]-Au3 and [G x C]-Au3 hybridized complexes are described and compared with the isolated Watson-Crick A x T and G x C ones. It is shown that enlarging the gold cluster size to Au6 results in a rather short gold-gold bond in the Watson-Crick interbase region of the [G x C]-Au6 complex that bridges the G x C pair and thus leads to a significant strengthening of G x C pairing.

  5. Effect of participatory women's groups and counselling through home visits on children's linear growth in rural eastern India (CARING trial): a cluster-randomised controlled trial.

    Science.gov (United States)

    Nair, Nirmala; Tripathy, Prasanta; Sachdev, H S; Pradhan, Hemanta; Bhattacharyya, Sanghita; Gope, Rajkumar; Gagrai, Sumitra; Rath, Shibanand; Rath, Suchitra; Sinha, Rajesh; Roy, Swati Sarbani; Shewale, Suhas; Singh, Vijay; Srivastava, Aradhana; Costello, Anthony; Copas, Andrew; Skordis-Worrall, Jolene; Haghparast-Bidgoli, Hassan; Saville, Naomi; Prost, Audrey

    2017-10-01

    Around 30% of the world's stunted children live in India. The Government of India has proposed a new cadre of community-based workers to improve nutrition in 200 districts. We aimed to find out the effect of such a worker carrying out home visits and participatory group meetings on children's linear growth. We did a cluster-randomised controlled trial in two adjoining districts of Jharkhand and Odisha, India. 120 clusters (around 1000 people each) were randomly allocated to intervention or control using a lottery. Randomisation took place in July, 2013, and was stratified by district and number of hamlets per cluster (0, 1-2, or ≥3), resulting in six strata. In each intervention cluster, a worker carried out one home visit in the third trimester of pregnancy, monthly visits to children younger than 2 years to support feeding, hygiene, care, and stimulation, as well as monthly women's group meetings to promote individual and community action for nutrition. Participants were pregnant women identified and recruited in the study clusters and their children. We excluded stillbirths and neonatal deaths, infants whose mothers died, those with congenital abnormalities, multiple births, and mother and infant pairs who migrated out of the study area permanently during the trial period. Data collectors visited each woman in pregnancy, within 72 h of her baby's birth, and at 3, 6, 9, 12, and 18 months after birth. The primary outcome was children's length-for-age Z score at 18 months of age. Analyses were by intention to treat. Due to the nature of the intervention, participants and the intervention team were not masked to allocation. Data collectors and the data manager were masked to allocation. The trial is registered as ISCRTN (51505201) and with the Clinical Trials Registry of India (number 2014/06/004664). Between Oct 1, 2013, and Dec 31, 2015, we recruited 5781 pregnant women. 3001 infants were born to pregnant women recruited between Oct 1, 2013, and Feb 10, 2015

  6. Community-led trials: Intervention co-design in a cluster randomised controlled trial.

    Science.gov (United States)

    Andersson, Neil

    2017-05-30

    In conventional randomised controlled trials (RCTs), researchers design the interventions. In the Camino Verde trial, each intervention community designed its own programmes to prevent dengue. Instead of fixed actions or menus of activities to choose from, the trial randomised clusters to a participatory research protocol that began with sharing and discussing evidence from a local survey, going on to local authorship of the action plan for vector control.Adding equitable stakeholder engagement to RCT infrastructure anchors the research culturally, making it more meaningful to stakeholders. Replicability in other conditions is straightforward, since all intervention clusters used the same engagement protocol to discuss and to mobilize for dengue prevention. The ethical codes associated with RCTs play out differently in community-led pragmatic trials, where communities essentially choose what they want to do. Several discussion groups in each intervention community produced multiple plans for prevention, recognising different time lines. Some chose fast turnarounds, like elimination of breeding sites, and some chose longer term actions like garbage disposal and improving water supplies.A big part of the skill set for community-led trials is being able to stand back and simply support communities in what they want to do and how they want to do it, something that does not come naturally to many vector control programs or to RCT researchers. Unexpected negative outcomes can come from the turbulence implicit in participatory research. One example was the gender dynamic in the Mexican arm of the Camino Verde trial. Strong involvement of women in dengue control activities seems to have discouraged men in settings where activity in public spaces or outside of the home would ordinarily be considered a "male competence".Community-led trials address the tension between one-size-fits-all programme interventions and local needs. Whatever the conventional wisdom about how

  7. Community-led trials: Intervention co-design in a cluster randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Neil Andersson

    2017-05-01

    Full Text Available Abstract In conventional randomised controlled trials (RCTs, researchers design the interventions. In the Camino Verde trial, each intervention community designed its own programmes to prevent dengue. Instead of fixed actions or menus of activities to choose from, the trial randomised clusters to a participatory research protocol that began with sharing and discussing evidence from a local survey, going on to local authorship of the action plan for vector control. Adding equitable stakeholder engagement to RCT infrastructure anchors the research culturally, making it more meaningful to stakeholders. Replicability in other conditions is straightforward, since all intervention clusters used the same engagement protocol to discuss and to mobilize for dengue prevention. The ethical codes associated with RCTs play out differently in community-led pragmatic trials, where communities essentially choose what they want to do. Several discussion groups in each intervention community produced multiple plans for prevention, recognising different time lines. Some chose fast turnarounds, like elimination of breeding sites, and some chose longer term actions like garbage disposal and improving water supplies. A big part of the skill set for community-led trials is being able to stand back and simply support communities in what they want to do and how they want to do it, something that does not come naturally to many vector control programs or to RCT researchers. Unexpected negative outcomes can come from the turbulence implicit in participatory research. One example was the gender dynamic in the Mexican arm of the Camino Verde trial. Strong involvement of women in dengue control activities seems to have discouraged men in settings where activity in public spaces or outside of the home would ordinarily be considered a “male competence”. Community-led trials address the tension between one-size-fits-all programme interventions and local needs. Whatever the

  8. Inadequacy of ethical conduct and reporting of stepped wedge cluster randomized trials: Results from a systematic review.

    Science.gov (United States)

    Taljaard, Monica; Hemming, Karla; Shah, Lena; Giraudeau, Bruno; Grimshaw, Jeremy M; Weijer, Charles

    2017-08-01

    Background/aims The use of the stepped wedge cluster randomized design is rapidly increasing. This design is commonly used to evaluate health policy and service delivery interventions. Stepped wedge cluster randomized trials have unique characteristics that complicate their ethical interpretation. The 2012 Ottawa Statement provides comprehensive guidance on the ethical design and conduct of cluster randomized trials, and the 2010 CONSORT extension for cluster randomized trials provides guidelines for reporting. Our aims were to assess the adequacy of the ethical conduct and reporting of stepped wedge trials to date, focusing on research ethics review and informed consent. Methods We conducted a systematic review of stepped wedge cluster randomized trials in health research published up to 2014 in English language journals. We extracted details of study intervention and data collection procedures, as well as reporting of research ethics review and informed consent. Two reviewers independently extracted data from each trial; discrepancies were resolved through discussion. We identified the presence of any research participants at the cluster level and the individual level. We assessed ethical conduct by tabulating reporting of research ethics review and informed consent against the presence of research participants. Results Of 32 identified stepped wedge trials, only 24 (75%) reported review by a research ethics committee, and only 16 (50%) reported informed consent from any research participants-yet, all trials included research participants at some level. In the subgroup of 20 trials with research participants at cluster level, only 4 (20%) reported informed consent from such participants; in 26 trials with individual-level research participants, only 15 (58%) reported their informed consent. Interventions (regardless of whether targeting cluster- or individual-level participants) were delivered at the group level in more than two-thirds of trials; nine trials (28

  9. Ethical and policy issues in cluster randomized trials: rationale and design of a mixed methods research study

    Directory of Open Access Journals (Sweden)

    Chaudhry Shazia H

    2009-07-01

    Full Text Available Abstract Background Cluster randomized trials are an increasingly important methodological tool in health research. In cluster randomized trials, intact social units or groups of individuals, such as medical practices, schools, or entire communities – rather than individual themselves – are randomly allocated to intervention or control conditions, while outcomes are then observed on individual cluster members. The substantial methodological differences between cluster randomized trials and conventional randomized trials pose serious challenges to the current conceptual framework for research ethics. The ethical implications of randomizing groups rather than individuals are not addressed in current research ethics guidelines, nor have they even been thoroughly explored. The main objectives of this research are to: (1 identify ethical issues arising in cluster trials and learn how they are currently being addressed; (2 understand how ethics reviews of cluster trials are carried out in different countries (Canada, the USA and the UK; (3 elicit the views and experiences of trial participants and cluster representatives; (4 develop well-grounded guidelines for the ethical conduct and review of cluster trials by conducting an extensive ethical analysis and organizing a consensus process; (5 disseminate the guidelines to researchers, research ethics boards (REBs, journal editors, and research funders. Methods We will use a mixed-methods (qualitative and quantitative approach incorporating both empirical and conceptual work. Empirical work will include a systematic review of a random sample of published trials, a survey and in-depth interviews with trialists, a survey of REBs, and in-depth interviews and focus group discussions with trial participants and gatekeepers. The empirical work will inform the concurrent ethical analysis which will lead to a guidance document laying out principles, policy options, and rationale for proposed guidelines. An

  10. The use of a versatile o-vanilloyl hydrazone ligand to prepare SMM-like Dy3 molecular cluster pair.

    Science.gov (United States)

    Xue, Shufang; Zhao, Lang; Guo, Yun-Nan; Zhang, Peng; Tang, Jinkui

    2012-09-14

    A novel lanthanide molecular cluster pair (MCP), displaying single molecule magnet behaviour, was assembled using the novel o-vanilloyl hydrazone ligand, versatile in terms of denticity, tautomerism and the rotatable C-C bond.

  11. An imbalance in cluster sizes does not lead to notable loss of power in cross-sectional, stepped-wedge cluster randomised trials with a continuous outcome.

    Science.gov (United States)

    Kristunas, Caroline A; Smith, Karen L; Gray, Laura J

    2017-03-07

    The current methodology for sample size calculations for stepped-wedge cluster randomised trials (SW-CRTs) is based on the assumption of equal cluster sizes. However, as is often the case in cluster randomised trials (CRTs), the clusters in SW-CRTs are likely to vary in size, which in other designs of CRT leads to a reduction in power. The effect of an imbalance in cluster size on the power of SW-CRTs has not previously been reported, nor what an appropriate adjustment to the sample size calculation should be to allow for any imbalance. We aimed to assess the impact of an imbalance in cluster size on the power of a cross-sectional SW-CRT and recommend a method for calculating the sample size of a SW-CRT when there is an imbalance in cluster size. The effect of varying degrees of imbalance in cluster size on the power of SW-CRTs was investigated using simulations. The sample size was calculated using both the standard method and two proposed adjusted design effects (DEs), based on those suggested for CRTs with unequal cluster sizes. The data were analysed using generalised estimating equations with an exchangeable correlation matrix and robust standard errors. An imbalance in cluster size was not found to have a notable effect on the power of SW-CRTs. The two proposed adjusted DEs resulted in trials that were generally considerably over-powered. We recommend that the standard method of sample size calculation for SW-CRTs be used, provided that the assumptions of the method hold. However, it would be beneficial to investigate, through simulation, what effect the maximum likely amount of inequality in cluster sizes would be on the power of the trial and whether any inflation of the sample size would be required.

  12. Role of pn-pairs in nuclear structure

    International Nuclear Information System (INIS)

    Nie, G.K.

    2003-01-01

    An α-cluster model of nuclear structure based on power of proton + neutron (pn)-pairs to bind themselves to α-clusters is proposed. The α-cluster is taken as the perfect condition of coupling of 2 pn- pairs, reminding complete electron shell in atomic physics. Pn-pairs create 2 other types of coupling of considerably less power between pn-pairs of nearby α-clusters ε α c and between pn-pair not bound into α-cluster with pn-pairs of nearby cluster ε pn c . Last two types of coupling are called covalent because of reminding similar electron coupling in chemistry. According the model nucleus is a liquid drop consisting of molecules, which are α-clusters, tied by covalent coupling with those ones which are in close vicinity. Then in case of even-even nuclei spin of the nucleus has to be zero I=0 + as sum of spinless particles. In case of nucleus has some nucleons (i) in intermolecular space, I=Σj i ; with taking into account that there is coupling of p and n in pn-pair. Therefore for 6 Li (1=0)I=2·1/2=1 + . The values ε α c , ε pn c and binding energy of the pn-pair itself ε pn have been estimated from analysis of binding energy of nuclei 6 Li, 10 B and 12 C. With the values the binding energy of the other nuclei with N=Z up to 58 Cu have been described with difference between experimental values and model ones in average less than 0.4 MeV. The structure reveals some regular forms, in which every cluster has reduced amount of covalent coupling, 3 or 4, and free pn-pair has 6 covalent coupling with 3 nearby clusters pn-pairs. Then the magic numbers are supposed to be the matter of geometry, when total amount of covalent couplings is optimal (minimal for the amount of clusters), α- clusters are placed in the same fixed distant from center of mass. It means that protons of the clusters can be considered as belonging to one shell. In the cluster model single particle effects have to be considered as single particle binding in one of the surface α-clusters

  13. Peer Coaches to Improve Diabetes Outcomes in Rural Alabama: A Cluster Randomized Trial.

    Science.gov (United States)

    Safford, Monika M; Andreae, Susan; Cherrington, Andrea L; Martin, Michelle Y; Halanych, Jewell; Lewis, Marquita; Patel, Ashruta; Johnson, Ethel; Clark, Debra; Gamboa, Christopher; Richman, Joshua S

    2015-08-01

    It is unclear whether peer coaching is effective in minority populations living with diabetes in hard-to-reach, under-resourced areas such as the rural South. We examined the effect of an innovative peer-coaching intervention plus brief education vs brief education alone on diabetes outcomes. This was a community-engaged, cluster-randomized, controlled trial with primary care practices and their surrounding communities serving as clusters. The trial enrolled 424 participants, with 360 completing baseline and follow-up data collection (84.9% retention). The primary outcomes were change in glycated hemoglobin (HbA1c), systolic blood pressure (BP), low density lipoprotein cholesterol (LDL-C), body mass index (BMI), and quality of life, with diabetes distress and patient activation as secondary outcomes. Peer coaches were trained for 2 days in community settings; the training emphasized motivational interviewing skills, diabetes basics, and goal setting. All participants received a 1-hour diabetes education class and a personalized diabetes report card at baseline. Intervention arm participants were also paired with peer coaches; the protocol called for telephone interactions weekly for the first 8 weeks, then monthly for a total of 10 months. Due to real-world constraints, follow-up was protracted, and intervention effects varied over time. The analysis that included the 68% of participants followed up by 15 months showed only a significant increase in patient activation in the intervention group. The analysis that included all participants who eventually completed follow-up revealed that intervention arm participants had significant differences in changes in systolic BP (P = .047), BMI (P = .02), quality of life (P = .003), diabetes distress (P = .004), and patient activation (P = .03), but not in HbA1c (P = .14) or LDL-C (P = .97). Telephone-delivered peer coaching holds promise to improve health for individuals with diabetes living in under-resourced areas. © 2015

  14. A systematic review of cluster randomised trials in residential facilities for older people suggests how to improve quality.

    Science.gov (United States)

    Diaz-Ordaz, Karla; Froud, Robert; Sheehan, Bart; Eldridge, Sandra

    2013-10-22

    Previous reviews of cluster randomised trials have been critical of the quality of the trials reviewed, but none has explored determinants of the quality of these trials in a specific field over an extended period of time. Recent work suggests that correct conduct and reporting of these trials may require more than published guidelines. In this review, our aim was to assess the quality of cluster randomised trials conducted in residential facilities for older people, and to determine whether (1) statistician involvement in the trial and (2) strength of journal endorsement of the Consolidated Standards of Reporting Trials (CONSORT) statement influence quality. We systematically identified trials randomising residential facilities for older people, or parts thereof, without language restrictions, up to the end of 2010, using National Library of Medicine (Medline) via PubMed and hand-searching. We based quality assessment criteria largely on the extended CONSORT statement for cluster randomised trials. We assessed statistician involvement based on statistician co-authorship, and strength of journal endorsement of the CONSORT statement from journal websites. 73 trials met our inclusion criteria. Of these, 20 (27%) reported accounting for clustering in sample size calculations and 54 (74%) in the analyses. In 29 trials (40%), methods used to identify/recruit participants were judged by us to have potentially caused bias or reporting was unclear to reach a conclusion. Some elements of quality improved over time but this appeared not to be related to the publication of the extended CONSORT statement for these trials. Trials with statistician/epidemiologist co-authors were more likely to account for clustering in sample size calculations (unadjusted odds ratio 5.4, 95% confidence interval 1.1 to 26.0) and analyses (unadjusted OR 3.2, 1.2 to 8.5). Journal endorsement of the CONSORT statement was not associated with trial quality. Despite international attempts to improve

  15. Making birthing safe for Pakistan women: a cluster randomized trial

    Directory of Open Access Journals (Sweden)

    Khan Muhammad

    2012-07-01

    Full Text Available Abstract Background Two out of three neonatal deaths occur in just 10 countries and Pakistan stands third among them. Maternal mortality is also high with most deaths occurring during labor, birth, and first few hours after birth. Enhanced access and utilization of skilled delivery and emergency obstetric care is the demonstrated strategy in reducing maternal and neonatal mortality. This trial aims to compare reduction in neonate mortality and utilization of available safe birthing and Emergency Obstetric and Neonatal Care services among pregnant mothers receiving ‘structured birth planning’, and/or ‘transport facilitation’ compared to routine care. Methods A pragmatic cluster randomized trial, with qualitative and economic studies, will be conducted in Jhang, Chiniot and Khanewal districts of Punjab, Pakistan, from February 2011 to May 2013. At least 29,295 pregnancies will be registered in the three arms, seven clusters per arm; 1 structured birth planning and travel facilitation, 2 structured birth planning, and 3 control arm. Trial will be conducted through the Lady Health Worker program. Main outcomes are difference in neonatal mortality and service utilization; maternal mortality being the secondary outcome. Cluster level analysis will be done according to intention-to-treat. Discussion A nationwide network of about 100,000 lady health workers is already involved in antenatal and postnatal care of pregnant women. They also act as “gatekeepers” for the child birthing services. This gate keeping role mainly includes counseling and referral for skill birth attendance and travel arrangements for emergency obstetric care (if required. The review of current arrangements and practices show that the care delivery process needs enhancement to include adequate information provision as well as informed “decision” making and planned “action” by the pregnant women. The proposed three-year research is to develop, through national

  16. Selection bias and subject refusal in a cluster-randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Rochelle Yang

    2017-07-01

    Full Text Available Abstract Background Selection bias and non-participation bias are major methodological concerns which impact external validity. Cluster-randomized controlled trials are especially prone to selection bias as it is impractical to blind clusters to their allocation into intervention or control. This study assessed the impact of selection bias in a large cluster-randomized controlled trial. Methods The Improved Cardiovascular Risk Reduction to Enhance Rural Primary Care (ICARE study examined the impact of a remote pharmacist-led intervention in twelve medical offices. To assess eligibility, a standardized form containing patient demographics and medical information was completed for each screened patient. Eligible patients were approached by the study coordinator for recruitment. Both the study coordinator and the patient were aware of the site’s allocation prior to consent. Patients who consented or declined to participate were compared across control and intervention arms for differing characteristics. Statistical significance was determined using a two-tailed, equal variance t-test and a chi-square test with adjusted Bonferroni p-values. Results were adjusted for random cluster variation. Results There were 2749 completed screening forms returned to research staff with 461 subjects who had either consented or declined participation. Patients with poorly controlled diabetes were found to be significantly more likely to decline participation in intervention sites compared to those in control sites. A higher mean diastolic blood pressure was seen in patients with uncontrolled hypertension who declined in the control sites compared to those who declined in the intervention sites. However, these findings were no longer significant after adjustment for random variation among the sites. After this adjustment, females were now found to be significantly more likely to consent than males (odds ratio = 1.41; 95% confidence interval = 1.03, 1

  17. Molecular [(Fe3)–(Fe3)] and [(Fe4)–(Fe4)] coordination cluster pairs as single or composite arrays.

    Science.gov (United States)

    Sañudo, E Carolina; Uber, Jorge Salinas; Pons Balagué, Alba; Roubeau, Olivier; Aromí, Guillem

    2012-08-06

    The synthesis of molecular cluster pairs is a challenge for coordination chemists due to the potential applications of these species in molecular spintronics or quantum computing. The ligand H(4)L, 1,3-bis-(3-oxo-3-(2-hydroxyphenyl)-propionyl)-2-methoxybenzene, has been successfully used to obtain a series of such complexes using the basic Fe(III) trinuclear carboxylates as starting materials. Synthetic control has allowed the isolation of the two molecular cluster pairs that form the composite [Fe(4)O(2)(PhCO(2))(6)(H(2)L)(pz)](2)[Fe(3)O(PhCO(2))(5)(py)(H(2)L)](2) (1). The dimers of trinuclear units, [Fe(3)O(PhCO(2))(5)(H(2)O)(H(2)L)](2) (2) and [Fe(3)O(o-MePhCO(2))(5)(H(2)L)(py)](2) (3), and the dimers of tetranuclear units, [Fe(4)O(2)(PhCO(2))(6)(H(2)L)(pz)](2) (4) and [Fe(4)O(2)(o-MePhCO(2))(6)(H(2)L)(pz)](2) (5), are presented here. The magnetic properties of the reported aggregates show that they are pairs of semi-independent clusters weakly interacting magnetically as required for two-qubit quantum gates.

  18. Poor uptake of an online intervention in a cluster randomised controlled trial of online diabetes education for rural general practitioners.

    Science.gov (United States)

    Paul, Christine L; Piterman, Leon; Shaw, Jonathan E; Kirby, Catherine; Forshaw, Kristy L; Robinson, Jennifer; Thepwongsa, Isaraporn; Sanson-Fisher, Robert W

    2017-03-23

    In Australia, rural and remote communities have high rates of diabetes-related death and hospitalisation. General practitioners (GPs) play a major role in diabetes detection and management. Education of GPs could optimise diabetes management and improve patient outcomes at a population level. The study aimed to describe the uptake of a continuing medical education intervention for rural GPs and its impact on the viability of a cluster randomised controlled trial of the effects of continuing medical education on whole-town diabetes monitoring and control. Trial design: the cluster randomised controlled trial involved towns as the unit of allocation and analysis with outcomes assessed by de-identified pathology data (not reported here). The intervention programme consisted of an online active learning module, direct electronic access to specialist advice and performance feedback. Multiple rounds of invitation were used to engage GPs with the online intervention content. Evidence-based strategies (e.g. pre-notification, rewards, incentives) were incorporated into the invitations to enrol in the programme. Recruitment to the programme was electronically monitored through the hosting software package during the study intervention period. Eleven matched pairs of towns were included in the study. There were 146 GPs in the 11 intervention towns, of whom 34 (23.3%) enrolled in the programme, and 8 (5.5%) completed the online learning module. No town had more than 10% of the resident GPs complete the learning module. There were no contacts made by GPs regarding requests for specialist advice. Consequently, the trial was discontinued. There is an ongoing need to engage primary care physicians in improving diabetes monitoring and management in rural areas. Online training options, while notionally attractive and accessible, are not likely to have high levels of uptake, even when evidence-based recruitment strategies are implemented. Australian New Zealand Clinical Trials

  19. Improving Language Comprehension in Preschool Children with Language Difficulties: A Cluster Randomized Trial

    Science.gov (United States)

    Hagen, Åste M.; Melby-Lervåg, Monica; Lervåg, Arne

    2017-01-01

    Background: Children with language comprehension difficulties are at risk of educational and social problems, which in turn impede employment prospects in adulthood. However, few randomized trials have examined how such problems can be ameliorated during the preschool years. Methods: We conducted a cluster randomized trial in 148 preschool…

  20. Recombination radius of a Frenkel pair and capture radius of a self-interstitial atom by vacancy clusters in bcc Fe

    International Nuclear Information System (INIS)

    Nakashima, Kenichi; Stoller, Roger E; Xu, Haixuan

    2015-01-01

    The recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in irradiated materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain. Values from 1.0a 0 to 3.3a 0 have been employed as a recombination radius in previous studies using OKMC and RT. The recombination process of a Frenkel pair is investigated at the atomic level using the self-evolved atomistic kinetic Monte Carlo (SEAKMC) method in this paper. SEAKMC calculations reveal that a self-interstitial atom recombines with a vacancy in a spontaneous reaction from several nearby sites following characteristic pathways. The recombination radius of a Frenkel pair is estimated to be 2.26a 0 by taking the average of the recombination distances from 80 simulation cases. In addition, we apply these procedures to the capture radius of a self-interstitial atom by a vacancy cluster. The capture radius is found to gradually increase with the size of the vacancy cluster. The fitting curve for the capture radius is obtained as a function of the number of vacancies in the cluster. (paper)

  1. Aggregator: a machine learning approach to identifying MEDLINE articles that derive from the same underlying clinical trial.

    Science.gov (United States)

    Shao, Weixiang; Adams, Clive E; Cohen, Aaron M; Davis, John M; McDonagh, Marian S; Thakurta, Sujata; Yu, Philip S; Smalheiser, Neil R

    2015-03-01

    It is important to identify separate publications that report outcomes from the same underlying clinical trial, in order to avoid over-counting these as independent pieces of evidence. We created positive and negative training sets (comprised of pairs of articles reporting on the same condition and intervention) that were, or were not, linked to the same clinicaltrials.gov trial registry number. Features were extracted from MEDLINE and PubMed metadata; pairwise similarity scores were modeled using logistic regression. Article pairs from the same trial were identified with high accuracy (F1 score=0.843). We also created a clustering tool, Aggregator, that takes as input a PubMed user query for RCTs on a given topic, and returns article clusters predicted to arise from the same clinical trial. Although painstaking examination of full-text may be needed to be conclusive, metadata are surprisingly accurate in predicting when two articles derive from the same underlying clinical trial. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Disseminating quality improvement: study protocol for a large cluster-randomized trial

    Directory of Open Access Journals (Sweden)

    French Michael T

    2011-04-01

    Full Text Available Abstract Background Dissemination is a critical facet of implementing quality improvement in organizations. As a field, addiction treatment has produced effective interventions but disseminated them slowly and reached only a fraction of people needing treatment. This study investigates four methods of disseminating quality improvement (QI to addiction treatment programs in the U.S. It is, to our knowledge, the largest study of organizational change ever conducted in healthcare. The trial seeks to determine the most cost-effective method of disseminating quality improvement in addiction treatment. Methods The study is evaluating the costs and effectiveness of different QI approaches by randomizing 201 addiction-treatment programs to four interventions. Each intervention used a web-based learning kit plus monthly phone calls, coaching, face-to-face meetings, or the combination of all three. Effectiveness is defined as reducing waiting time (days between first contact and treatment, increasing program admissions, and increasing continuation in treatment. Opportunity costs will be estimated for the resources associated with providing the services. Outcomes The study has three primary outcomes: waiting time, annual program admissions, and continuation in treatment. Secondary outcomes include: voluntary employee turnover, treatment completion, and operating margin. We are also seeking to understand the role of mediators, moderators, and other factors related to an organization's success in making changes. Analysis We are fitting a mixed-effect regression model to each program's average monthly waiting time and continuation rates (based on aggregated client records, including terms to isolate state and intervention effects. Admissions to treatment are aggregated to a yearly level to compensate for seasonality. We will order the interventions by cost to compare them pair-wise to the lowest cost intervention (monthly phone calls. All randomized sites

  3. Comparison of population-averaged and cluster-specific models for the analysis of cluster randomized trials with missing binary outcomes: a simulation study

    Directory of Open Access Journals (Sweden)

    Ma Jinhui

    2013-01-01

    Full Text Available Abstracts Background The objective of this simulation study is to compare the accuracy and efficiency of population-averaged (i.e. generalized estimating equations (GEE and cluster-specific (i.e. random-effects logistic regression (RELR models for analyzing data from cluster randomized trials (CRTs with missing binary responses. Methods In this simulation study, clustered responses were generated from a beta-binomial distribution. The number of clusters per trial arm, the number of subjects per cluster, intra-cluster correlation coefficient, and the percentage of missing data were allowed to vary. Under the assumption of covariate dependent missingness, missing outcomes were handled by complete case analysis, standard multiple imputation (MI and within-cluster MI strategies. Data were analyzed using GEE and RELR. Performance of the methods was assessed using standardized bias, empirical standard error, root mean squared error (RMSE, and coverage probability. Results GEE performs well on all four measures — provided the downward bias of the standard error (when the number of clusters per arm is small is adjusted appropriately — under the following scenarios: complete case analysis for CRTs with a small amount of missing data; standard MI for CRTs with variance inflation factor (VIF 50. RELR performs well only when a small amount of data was missing, and complete case analysis was applied. Conclusion GEE performs well as long as appropriate missing data strategies are adopted based on the design of CRTs and the percentage of missing data. In contrast, RELR does not perform well when either standard or within-cluster MI strategy is applied prior to the analysis.

  4. Handling missing data in cluster randomized trials: A demonstration of multiple imputation with PAN through SAS

    Directory of Open Access Journals (Sweden)

    Jiangxiu Zhou

    2014-09-01

    Full Text Available The purpose of this study is to demonstrate a way of dealing with missing data in clustered randomized trials by doing multiple imputation (MI with the PAN package in R through SAS. The procedure for doing MI with PAN through SAS is demonstrated in detail in order for researchers to be able to use this procedure with their own data. An illustration of the technique with empirical data was also included. In this illustration thePAN results were compared with pairwise deletion and three types of MI: (1 Normal Model (NM-MI ignoring the cluster structure; (2 NM-MI with dummy-coded cluster variables (fixed cluster structure; and (3 a hybrid NM-MI which imputes half the time ignoring the cluster structure, and the other half including the dummy-coded cluster variables. The empirical analysis showed that using PAN and the other strategies produced comparable parameter estimates. However, the dummy-coded MI overestimated the intraclass correlation, whereas MI ignoring the cluster structure and the hybrid MI underestimated the intraclass correlation. When compared with PAN, the p-value and standard error for the treatment effect were higher with dummy-coded MI, and lower with MI ignoring the clusterstructure, the hybrid MI approach, and pairwise deletion. Previous studies have shown that NM-MI is not appropriate for handling missing data in clustered randomized trials. This approach, in addition to the pairwise deletion approach, leads to a biased intraclass correlation and faultystatistical conclusions. Imputation in clustered randomized trials should be performed with PAN. We have demonstrated an easy way for using PAN through SAS.

  5. The Design of Cluster Randomized Trials with Random Cross-Classifications

    Science.gov (United States)

    Moerbeek, Mirjam; Safarkhani, Maryam

    2018-01-01

    Data from cluster randomized trials do not always have a pure hierarchical structure. For instance, students are nested within schools that may be crossed by neighborhoods, and soldiers are nested within army units that may be crossed by mental health-care professionals. It is important that the random cross-classification is taken into account…

  6. Hubbard pair cluster in the external fields. Studies of the magnetic properties

    Science.gov (United States)

    Balcerzak, T.; Szałowski, K.

    2018-06-01

    The magnetic properties of the two-site Hubbard cluster (dimer or pair), embedded in the external electric and magnetic fields and treated as the open system, are studied by means of the exact diagonalization of the Hamiltonian. The formalism of the grand canonical ensemble is adopted. The phase diagrams, on-site magnetizations, spin-spin correlations, mean occupation numbers and hopping energy are investigated and illustrated in figures. An influence of temperature, mean electron concentration, Coulomb U parameter and external fields on the quantities of interest is presented and discussed. In particular, the anomalous behaviour of the magnetization and correlation function vs. temperature near the critical magnetic field is found. Also, the effect of magnetization switching by the external fields is demonstrated.

  7. How large are the consequences of covariate imbalance in cluster randomized trials: a simulation study with a continuous outcome and a binary covariate at the cluster level.

    Science.gov (United States)

    Moerbeek, Mirjam; van Schie, Sander

    2016-07-11

    The number of clusters in a cluster randomized trial is often low. It is therefore likely random assignment of clusters to treatment conditions results in covariate imbalance. There are no studies that quantify the consequences of covariate imbalance in cluster randomized trials on parameter and standard error bias and on power to detect treatment effects. The consequences of covariance imbalance in unadjusted and adjusted linear mixed models are investigated by means of a simulation study. The factors in this study are the degree of imbalance, the covariate effect size, the cluster size and the intraclass correlation coefficient. The covariate is binary and measured at the cluster level; the outcome is continuous and measured at the individual level. The results show covariate imbalance results in negligible parameter bias and small standard error bias in adjusted linear mixed models. Ignoring the possibility of covariate imbalance while calculating the sample size at the cluster level may result in a loss in power of at most 25 % in the adjusted linear mixed model. The results are more severe for the unadjusted linear mixed model: parameter biases up to 100 % and standard error biases up to 200 % may be observed. Power levels based on the unadjusted linear mixed model are often too low. The consequences are most severe for large clusters and/or small intraclass correlation coefficients since then the required number of clusters to achieve a desired power level is smallest. The possibility of covariate imbalance should be taken into account while calculating the sample size of a cluster randomized trial. Otherwise more sophisticated methods to randomize clusters to treatments should be used, such as stratification or balance algorithms. All relevant covariates should be carefully identified, be actually measured and included in the statistical model to avoid severe levels of parameter and standard error bias and insufficient power levels.

  8. Does clinical equipoise apply to cluster randomized trials in health research?

    Science.gov (United States)

    2011-01-01

    This article is part of a series of papers examining ethical issues in cluster randomized trials (CRTs) in health research. In the introductory paper in this series, Weijer and colleagues set out six areas of inquiry that must be addressed if the cluster trial is to be set on a firm ethical foundation. This paper addresses the third of the questions posed, namely, does clinical equipoise apply to CRTs in health research? The ethical principle of beneficence is the moral obligation not to harm needlessly and, when possible, to promote the welfare of research subjects. Two related ethical problems have been discussed in the CRT literature. First, are control groups that receive only usual care unduly disadvantaged? Second, when accumulating data suggests the superiority of one intervention in a trial, is there an ethical obligation to act? In individually randomized trials involving patients, similar questions are addressed by the concept of clinical equipoise, that is, the ethical requirement that, at the start of a trial, there be a state of honest, professional disagreement in the community of expert practitioners as to the preferred treatment. Since CRTs may not involve physician-researchers and patient-subjects, the applicability of clinical equipoise to CRTs is uncertain. Here we argue that clinical equipoise may be usefully grounded in a trust relationship between the state and research subjects, and, as a result, clinical equipoise is applicable to CRTs. Clinical equipoise is used to argue that control groups receiving only usual care are not disadvantaged so long as the evidence supporting the experimental and control interventions is such that experts would disagree as to which is preferred. Further, while data accumulating during the course of a CRT may favor one intervention over another, clinical equipoise supports continuing the trial until the results are likely to be broadly convincing, often coinciding with the planned completion of the trial

  9. Actinide chemistry using singlet-paired coupled cluster and its combinations with density functionals

    Science.gov (United States)

    Garza, Alejandro J.; Sousa Alencar, Ana G.; Scuseria, Gustavo E.

    2015-12-01

    Singlet-paired coupled cluster doubles (CCD0) is a simplification of CCD that relinquishes a fraction of dynamic correlation in order to be able to describe static correlation. Combinations of CCD0 with density functionals that recover specifically the dynamic correlation missing in the former have also been developed recently. Here, we assess the accuracy of CCD0 and CCD0+DFT (and variants of these using Brueckner orbitals) as compared to well-established quantum chemical methods for describing ground-state properties of singlet actinide molecules. The f0 actinyl series (UO22+, NpO23+, PuO24+), the isoelectronic NUN, and thorium (ThO, ThO2+) and nobelium (NoO, NoO2) oxides are studied.

  10. Standardized Effect Size Measures for Mediation Analysis in Cluster-Randomized Trials

    Science.gov (United States)

    Stapleton, Laura M.; Pituch, Keenan A.; Dion, Eric

    2015-01-01

    This article presents 3 standardized effect size measures to use when sharing results of an analysis of mediation of treatment effects for cluster-randomized trials. The authors discuss 3 examples of mediation analysis (upper-level mediation, cross-level mediation, and cross-level mediation with a contextual effect) with demonstration of the…

  11. Analysis of ligand-protein exchange by Clustering of Ligand Diffusion Coefficient Pairs (CoLD-CoP)

    Science.gov (United States)

    Snyder, David A.; Chantova, Mihaela; Chaudhry, Saadia

    2015-06-01

    NMR spectroscopy is a powerful tool in describing protein structures and protein activity for pharmaceutical and biochemical development. This study describes a method to determine weak binding ligands in biological systems by using hierarchic diffusion coefficient clustering of multidimensional data obtained with a 400 MHz Bruker NMR. Comparison of DOSY spectrums of ligands of the chemical library in the presence and absence of target proteins show translational diffusion rates for small molecules upon interaction with macromolecules. For weak binders such as compounds found in fragment libraries, changes in diffusion rates upon macromolecular binding are on the order of the precision of DOSY diffusion measurements, and identifying such subtle shifts in diffusion requires careful statistical analysis. The "CoLD-CoP" (Clustering of Ligand Diffusion Coefficient Pairs) method presented here uses SAHN clustering to identify protein-binders in a chemical library or even a not fully characterized metabolite mixture. We will show how DOSY NMR and the "CoLD-CoP" method complement each other in identifying the most suitable candidates for lysozyme and wheat germ acid phosphatase.

  12. Relative efficiency of unequal versus equal cluster sizes in cluster randomized trials using generalized estimating equation models.

    Science.gov (United States)

    Liu, Jingxia; Colditz, Graham A

    2018-05-01

    There is growing interest in conducting cluster randomized trials (CRTs). For simplicity in sample size calculation, the cluster sizes are assumed to be identical across all clusters. However, equal cluster sizes are not guaranteed in practice. Therefore, the relative efficiency (RE) of unequal versus equal cluster sizes has been investigated when testing the treatment effect. One of the most important approaches to analyze a set of correlated data is the generalized estimating equation (GEE) proposed by Liang and Zeger, in which the "working correlation structure" is introduced and the association pattern depends on a vector of association parameters denoted by ρ. In this paper, we utilize GEE models to test the treatment effect in a two-group comparison for continuous, binary, or count data in CRTs. The variances of the estimator of the treatment effect are derived for the different types of outcome. RE is defined as the ratio of variance of the estimator of the treatment effect for equal to unequal cluster sizes. We discuss a commonly used structure in CRTs-exchangeable, and derive the simpler formula of RE with continuous, binary, and count outcomes. Finally, REs are investigated for several scenarios of cluster size distributions through simulation studies. We propose an adjusted sample size due to efficiency loss. Additionally, we also propose an optimal sample size estimation based on the GEE models under a fixed budget for known and unknown association parameter (ρ) in the working correlation structure within the cluster. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Novel Ordered Stepped-Wedge Cluster Trial Designs for Detecting Ebola Vaccine Efficacy Using a Spatially Structured Mathematical Model.

    Directory of Open Access Journals (Sweden)

    Ibrahim Diakite

    2016-08-01

    Full Text Available During the 2014 Ebola virus disease (EVD outbreak, policy-makers were confronted with difficult decisions on how best to test the efficacy of EVD vaccines. On one hand, many were reluctant to withhold a vaccine that might prevent a fatal disease from study participants randomized to a control arm. On the other, regulatory bodies called for rigorous placebo-controlled trials to permit direct measurement of vaccine efficacy prior to approval of the products. A stepped-wedge cluster study (SWCT was proposed as an alternative to a more traditional randomized controlled vaccine trial to address these concerns. Here, we propose novel "ordered stepped-wedge cluster trial" (OSWCT designs to further mitigate tradeoffs between ethical concerns, logistics, and statistical rigor.We constructed a spatially structured mathematical model of the EVD outbreak in Sierra Leone. We used the output of this model to simulate and compare a series of stepped-wedge cluster vaccine studies. Our model reproduced the observed order of first case occurrence within districts of Sierra Leone. Depending on the infection risk within the trial population and the trial start dates, the statistical power to detect a vaccine efficacy of 90% varied from 14% to 32% for standard SWCT, and from 67% to 91% for OSWCTs for an alpha error of 5%. The model's projection of first case occurrence was robust to changes in disease natural history parameters.Ordering clusters in a step-wedge trial based on the cluster's underlying risk of infection as predicted by a spatial model can increase the statistical power of a SWCT. In the event of another hemorrhagic fever outbreak, implementation of our proposed OSWCT designs could improve statistical power when a step-wedge study is desirable based on either ethical concerns or logistical constraints.

  14. Structure based alignment and clustering of proteins (STRALCP)

    Science.gov (United States)

    Zemla, Adam T.; Zhou, Carol E.; Smith, Jason R.; Lam, Marisa W.

    2013-06-18

    Disclosed are computational methods of clustering a set of protein structures based on local and pair-wise global similarity values. Pair-wise local and global similarity values are generated based on pair-wise structural alignments for each protein in the set of protein structures. Initially, the protein structures are clustered based on pair-wise local similarity values. The protein structures are then clustered based on pair-wise global similarity values. For each given cluster both a representative structure and spans of conserved residues are identified. The representative protein structure is used to assign newly-solved protein structures to a group. The spans are used to characterize conservation and assign a "structural footprint" to the cluster.

  15. Interacting star clusters in the Large Magellanic Cloud. Overmerging problem solved by cluster group formation

    Science.gov (United States)

    Leon, Stéphane; Bergond, Gilles; Vallenari, Antonella

    1999-04-01

    We present the tidal tail distributions of a sample of candidate binary clusters located in the bar of the Large Magellanic Cloud (LMC). One isolated cluster, SL 268, is presented in order to study the effect of the LMC tidal field. All the candidate binary clusters show tidal tails, confirming that the pairs are formed by physically linked objects. The stellar mass in the tails covers a large range, from 1.8x 10(3) to 3x 10(4) \\msun. We derive a total mass estimate for SL 268 and SL 356. At large radii, the projected density profiles of SL 268 and SL 356 fall off as r(-gamma ) , with gamma = 2.27 and gamma =3.44, respectively. Out of 4 pairs or multiple systems, 2 are older than the theoretical survival time of binary clusters (going from a few 10(6) years to 10(8) years). A pair shows too large age difference between the components to be consistent with classical theoretical models of binary cluster formation (Fujimoto & Kumai \\cite{fujimoto97}). We refer to this as the ``overmerging'' problem. A different scenario is proposed: the formation proceeds in large molecular complexes giving birth to groups of clusters over a few 10(7) years. In these groups the expected cluster encounter rate is larger, and tidal capture has higher probability. Cluster pairs are not born together through the splitting of the parent cloud, but formed later by tidal capture. For 3 pairs, we tentatively identify the star cluster group (SCG) memberships. The SCG formation, through the recent cluster starburst triggered by the LMC-SMC encounter, in contrast with the quiescent open cluster formation in the Milky Way can be an explanation to the paucity of binary clusters observed in our Galaxy. Based on observations collected at the European Southern Observatory, La Silla, Chile}

  16. Single-Trial Classification of Bistable Perception by Integrating Empirical Mode Decomposition, Clustering, and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Hualou Liang

    2008-04-01

    Full Text Available We propose an empirical mode decomposition (EMD- based method to extract features from the multichannel recordings of local field potential (LFP, collected from the middle temporal (MT visual cortex in a macaque monkey, for decoding its bistable structure-from-motion (SFM perception. The feature extraction approach consists of three stages. First, we employ EMD to decompose nonstationary single-trial time series into narrowband components called intrinsic mode functions (IMFs with time scales dependent on the data. Second, we adopt unsupervised K-means clustering to group the IMFs and residues into several clusters across all trials and channels. Third, we use the supervised common spatial patterns (CSP approach to design spatial filters for the clustered spatiotemporal signals. We exploit the support vector machine (SVM classifier on the extracted features to decode the reported perception on a single-trial basis. We demonstrate that the CSP feature of the cluster in the gamma frequency band outperforms the features in other frequency bands and leads to the best decoding performance. We also show that the EMD-based feature extraction can be useful for evoked potential estimation. Our proposed feature extraction approach may have potential for many applications involving nonstationary multivariable time series such as brain-computer interfaces (BCI.

  17. Remedial after-school support classes offered in rural Gambia (The SCORE trial): study protocol for a cluster randomized controlled trial.

    Science.gov (United States)

    Boone, Peter; Camara, Alpha; Eble, Alex; Elbourne, Diana; Fernandes, Samory; Frost, Chris; Jayanty, Chitra; Lenin, Maitri; Silva, Ana Filipa

    2015-12-16

    Low education levels are endemic in much of the developing world, particularly in rural areas where traditional government-provided public services often have difficulty reaching beneficiaries. Providing trained para-teachers to teach regular after-school remedial education classes has been shown to improve literacy and numeracy in children of primary school age residing in such areas in India. This trial investigates whether such an intervention can also be effective in a West African setting with similarly low learning levels and difficult geographic access. cluster-randomized controlled trial. Clusters: villages or groups of villages with 15-300 households and at least 15 eligible children in the Lower River and North Bank Regions of The Gambia. children born between 1 September 2007 and 31 August 2009 planning to enter the first grade, for the first time, in the 2015-2016 school year in eligible villages. We anticipate enrolling approximately 150 clusters of villages with approximately 6000 children as participants. a program providing remedial after-school lessons, focusing on literacy and numeracy, 5 to 6 days a week for 3 years to eligible children, based on the intervention evaluated in the Support To Rural India's Public Education System (STRIPES) trial (PLoS ONE 8(7):e65775). both the intervention and control groups will receive small bundles of useful materials during annual data collection as recompense for their time. If the education intervention is shown to be cost-effective at raising learning levels, it is expected that the control group villages will receive the intervention for several years after the trial results are available. the primary outcome of the trial is a composite mathematics and language test score. Secondary outcomes include school attendance, enrollment, performance on nationally administered exams, parents' spending on education, spillover learning to siblings and family members, and school-related time use of parents and

  18. Experimental many-pairs nonlocality

    Science.gov (United States)

    Poh, Hou Shun; Cerè, Alessandro; Bancal, Jean-Daniel; Cai, Yu; Sangouard, Nicolas; Scarani, Valerio; Kurtsiefer, Christian

    2017-08-01

    Collective measurements on large quantum systems together with a majority voting strategy can lead to a violation of the Clauser-Horne-Shimony-Holt Bell inequality. In the presence of many entangled pairs, this violation decreases quickly with the number of pairs and vanishes for some critical pair number that is a function of the noise present in the system. Here we show that a different binning strategy can lead to a more substantial Bell violation when the noise is sufficiently small. Given the relation between the critical pair number and the source noise, we then present an experiment where the critical pair number is used to quantify the quality of a high visibility photon pair source. Our results demonstrate nonlocal correlations using collective measurements operating on clusters of more than 40 photon pairs.

  19. A multifaceted intervention to improve mental health literacy in students of a multicampus university: a cluster randomised trial.

    Science.gov (United States)

    Reavley, Nicola J; McCann, Terence V; Cvetkovski, Stefan; Jorm, Anthony F

    2014-10-01

    The aim of the current study was to assess whether a multifaceted intervention could improve mental health literacy, facilitate help seeking and reduce psychological distress and alcohol misuse in students of a multicampus university in Melbourne, Australia. In this cluster randomized trial, nine university campuses were paired (some pairs included more than one campus), with one of each pair randomly assigned to either the intervention or control condition. The interventions were designed to be whole-of-campus and to run over 2 academic years with their effectiveness assessed through recruitment of a monitoring sample of students from each campus. Interventions included emails, posters, campus events, factsheets/booklets and mental health first aid training courses. Participants had a 20-min telephone interview at baseline and at the end of academic years 1 and 2. This assessed mental health literacy, help seeking, psychological distress and alcohol use. The primary outcomes were depression and anxiety levels and alcohol use and pertained to the individual level. There were no effects on psychological distress and alcohol use. Recall of intervention elements was greater in the intervention group at the end of year 2. Students in the intervention group were more likely to say they would go to a drug and alcohol centre for alcohol problems at the end of 6 months. Although education and awareness may play a role in improving mental health literacy, it is likely that, to achieve changes in psychological distress, interventions would need to be more personalized and intensive.

  20. A new mother-child play activity program to decrease parenting stress and improve child cognitive abilities: a cluster randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Tachibana

    Full Text Available BACKGROUND: We propose a new play activity intervention program for mothers and children. Our interdisciplinary program integrates four fields of child-related sciences: neuroscience, preschool pedagogy, developmental psychology, and child and maternal psychiatry. To determine the effect of this intervention on child and mother psychosocial problems related to parenting stress and on the children's cognitive abilities, we performed a cluster randomized controlled trial. METHODOLOGY/PRINCIPAL FINDINGS: Participants were 238 pairs of mothers and typically developing preschool children (ages 4-6 years old from Wakakusa kindergarten in Japan. The pairs were asked to play at home for about 10 min a day, 5 days a week for 3 months. Participants were randomly assigned to the intervention or control group by class unit. The Parenting Stress Index (PSI (for mothers, the Goodenough Draw-a-Man intelligence test (DAM, and the new S-S intelligence test (NS-SIT (for children were administered prior to and 3 months after the intervention period. Pre-post changes in test scores were compared between the groups using a linear mixed-effects model analysis. The primary outcomes were the Total score on the child domain of the PSI (for child psychosocial problems related to parenting stress, Total score on the parent domain of the PSI (for maternal psychosocial problems related to parenting stress, and the score on the DAM (for child cognitive abilities. The results of the PSI suggested that the program may reduce parenting stress. The results of the cognitive tests suggested that the program may improve the children's fluid intelligence, working memory, and processing speed. CONCLUSIONS/SIGNIFICANCE: Our intervention program may ameliorate the children's psychosocial problems related to parenting stress and increase their cognitive abilities. TRIAL REGISTRATION: UMIN Clinical Trials Registry UMIN000002265.

  1. The Effectiveness of Healthy Start Home Visit Program: Cluster Randomized Controlled Trial

    Science.gov (United States)

    Leung, Cynthia; Tsang, Sandra; Heung, Kitty

    2015-01-01

    Purpose: The study reported the effectiveness of a home visit program for disadvantaged Chinese parents with preschool children, using cluster randomized controlled trial design. Method: Participants included 191 parents and their children from 24 preschools, with 84 dyads (12 preschools) in the intervention group and 107 dyads (12 preschools) in…

  2. Efficacy of community-based physiotherapy networks for patients with Parkinson's disease: a cluster-randomised trial.

    Science.gov (United States)

    Munneke, Marten; Nijkrake, Maarten J; Keus, Samyra Hj; Kwakkel, Gert; Berendse, Henk W; Roos, Raymund Ac; Borm, George F; Adang, Eddy M; Overeem, Sebastiaan; Bloem, Bastiaan R

    2010-01-01

    Many patients with Parkinson's disease are treated with physiotherapy. We have developed a community-based professional network (ParkinsonNet) that involves training of a selected number of expert physiotherapists to work according to evidence-based recommendations, and structured referrals to these trained physiotherapists to increase the numbers of patients they treat. We aimed to assess the efficacy of this approach for improving health-care outcomes. Between February, 2005, and August, 2007, we did a cluster-randomised trial with 16 clusters (defined as community hospitals and their catchment area). Clusters were randomly allocated by use of a variance minimisation algorithm to ParkinsonNet care (n=8) or usual care (n=8). Patients were assessed at baseline and at 8, 16, and 24 weeks of follow-up. The primary outcome was a patient preference disability score, the patient-specific index score, at 16 weeks. Health secondary outcomes were functional mobility, mobility-related quality of life, and total societal costs over 24 weeks. Analysis was by intention to treat. This trial is registered, number NCT00330694. We included 699 patients. Baseline characteristics of the patients were comparable between the ParkinsonNet clusters (n=358) and usual-care clusters (n=341). The primary endpoint was similar for patients within the ParkinsonNet clusters (mean 47.7, SD 21.9) and control clusters (48.3, 22.4). Health secondary endpoints were also similar for patients in both study groups. Total costs over 24 weeks were lower in ParkinsonNet clusters compared with usual-care clusters (difference euro727; 95% CI 56-1399). Implementation of ParkinsonNet networks did not change health outcomes for patients living in ParkinsonNet clusters. However, health-care costs were reduced in ParkinsonNet clusters compared with usual-care clusters. ZonMw; Netherlands Organisation for Scientific Research; Dutch Parkinson's Disease Society; National Parkinson Foundation; Stichting Robuust

  3. Objectively Measured Baseline Physical Activity Patterns in Women in the mPED Trial: Cluster Analysis.

    Science.gov (United States)

    Fukuoka, Yoshimi; Zhou, Mo; Vittinghoff, Eric; Haskell, William; Goldberg, Ken; Aswani, Anil

    2018-02-01

    Determining patterns of physical activity throughout the day could assist in developing more personalized interventions or physical activity guidelines in general and, in particular, for women who are less likely to be physically active than men. The aims of this report are to identify clusters of women based on accelerometer-measured baseline raw metabolic equivalent of task (MET) values and a normalized version of the METs ≥3 data, and to compare sociodemographic and cardiometabolic risks among these identified clusters. A total of 215 women who were enrolled in the Mobile Phone Based Physical Activity Education (mPED) trial and wore an accelerometer for at least 8 hours per day for the 7 days prior to the randomization visit were analyzed. The k-means clustering method and the Lloyd algorithm were used on the data. We used the elbow method to choose the number of clusters, looking at the percentage of variance explained as a function of the number of clusters. The results of the k-means cluster analyses of raw METs revealed three different clusters. The unengaged group (n=102) had the highest depressive symptoms score compared with the afternoon engaged (n=65) and morning engaged (n=48) groups (overall Pcluster groups using a large national dataset. ClinicalTrials.gov NCT01280812; https://clinicaltrials.gov/ct2/show/NCT01280812 (Archived by WebCite at http://www.webcitation.org/6vVyLzwft). ©Yoshimi Fukuoka, Mo Zhou, Eric Vittinghoff, William Haskell, Ken Goldberg, Anil Aswani. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 01.02.2018.

  4. A Cluster-Randomized Trial of Restorative Practices: An Illustration to Spur High-Quality Research and Evaluation

    Science.gov (United States)

    Acosta, Joie D.; Chinman, Matthew; Ebener, Patricia; Phillips, Andrea; Xenakis, Lea; Malone, Patrick S.

    2016-01-01

    Restorative practices in schools lack rigorous evaluation studies. As an example of rigorous school-based research, this article describes the first randomized control trial of restorative practices to date, the Study of Restorative Practices. It is a 5-year, cluster-randomized controlled trial (RCT) of the Restorative Practices Intervention (RPI)…

  5. A comparison of confidence interval methods for the intraclass correlation coefficient in community-based cluster randomization trials with a binary outcome.

    Science.gov (United States)

    Braschel, Melissa C; Svec, Ivana; Darlington, Gerarda A; Donner, Allan

    2016-04-01

    Many investigators rely on previously published point estimates of the intraclass correlation coefficient rather than on their associated confidence intervals to determine the required size of a newly planned cluster randomized trial. Although confidence interval methods for the intraclass correlation coefficient that can be applied to community-based trials have been developed for a continuous outcome variable, fewer methods exist for a binary outcome variable. The aim of this study is to evaluate confidence interval methods for the intraclass correlation coefficient applied to binary outcomes in community intervention trials enrolling a small number of large clusters. Existing methods for confidence interval construction are examined and compared to a new ad hoc approach based on dividing clusters into a large number of smaller sub-clusters and subsequently applying existing methods to the resulting data. Monte Carlo simulation is used to assess the width and coverage of confidence intervals for the intraclass correlation coefficient based on Smith's large sample approximation of the standard error of the one-way analysis of variance estimator, an inverted modified Wald test for the Fleiss-Cuzick estimator, and intervals constructed using a bootstrap-t applied to a variance-stabilizing transformation of the intraclass correlation coefficient estimate. In addition, a new approach is applied in which clusters are randomly divided into a large number of smaller sub-clusters with the same methods applied to these data (with the exception of the bootstrap-t interval, which assumes large cluster sizes). These methods are also applied to a cluster randomized trial on adolescent tobacco use for illustration. When applied to a binary outcome variable in a small number of large clusters, existing confidence interval methods for the intraclass correlation coefficient provide poor coverage. However, confidence intervals constructed using the new approach combined with Smith

  6. Implementation of client versus care-provider strategies to improve external cephalic version rates: a cluster randomized controlled trial

    NARCIS (Netherlands)

    Vlemmix, Floortje; Rosman, Ageeth N.; Rijnders, Marlies E.; Beuckens, Antje; Opmeer, Brent C.; Mol, Ben W. J.; Kok, Marjolein; Fleuren, Margot A. H.

    2015-01-01

    To determine the effectiveness of a client or care-provider strategy to improve the implementation of external cephalic version. Cluster randomized controlled trial. Twenty-five clusters; hospitals and their referring midwifery practices randomly selected in the Netherlands. Singleton breech

  7. Implementation of client versus care-provider strategies to improve external cephalic version rates: a cluster randomized controlled trial

    NARCIS (Netherlands)

    Vlemmix, F.; Rosman, A.N.; Rijnders, M.E.; Beuckens, A.; Opmeer, B.C.; Mol, B.W.J.; Kok, M.; Fleuren, M.A.H.

    2015-01-01

    Onjective: To determine the effectiveness of a client or care-provider strategy to improve the implementation of external cephalic version. Design: Cluster randomized controlled trial.Setting: Twenty-five clusters; hospitals and their referring midwifery practices randomly selected in the

  8. Comparison and combination of "direct" and fragment based local correlation methods: Cluster in molecules and domain based local pair natural orbital perturbation and coupled cluster theories

    Science.gov (United States)

    Guo, Yang; Becker, Ute; Neese, Frank

    2018-03-01

    Local correlation theories have been developed in two main flavors: (1) "direct" local correlation methods apply local approximation to the canonical equations and (2) fragment based methods reconstruct the correlation energy from a series of smaller calculations on subsystems. The present work serves two purposes. First, we investigate the relative efficiencies of the two approaches using the domain-based local pair natural orbital (DLPNO) approach as the "direct" method and the cluster in molecule (CIM) approach as the fragment based approach. Both approaches are applied in conjunction with second-order many-body perturbation theory (MP2) as well as coupled-cluster theory with single-, double- and perturbative triple excitations [CCSD(T)]. Second, we have investigated the possible merits of combining the two approaches by performing CIM calculations with DLPNO methods serving as the method of choice for performing the subsystem calculations. Our cluster-in-molecule approach is closely related to but slightly deviates from approaches in the literature since we have avoided real space cutoffs. Moreover, the neglected distant pair correlations in the previous CIM approach are considered approximately. Six very large molecules (503-2380 atoms) were studied. At both MP2 and CCSD(T) levels of theory, the CIM and DLPNO methods show similar efficiency. However, DLPNO methods are more accurate for 3-dimensional systems. While we have found only little incentive for the combination of CIM with DLPNO-MP2, the situation is different for CIM-DLPNO-CCSD(T). This combination is attractive because (1) the better parallelization opportunities offered by CIM; (2) the methodology is less memory intensive than the genuine DLPNO-CCSD(T) method and, hence, allows for large calculations on more modest hardware; and (3) the methodology is applicable and efficient in the frequently met cases, where the largest subsystem calculation is too large for the canonical CCSD(T) method.

  9. Increasing students' physical activity during school physical education: rationale and protocol for the SELF-FIT cluster randomized controlled trial.

    Science.gov (United States)

    Ha, Amy S; Lonsdale, Chris; Lubans, David R; Ng, Johan Y Y

    2017-07-11

    The Self-determined Exercise and Learning For FITness (SELF-FIT) is a multi-component school-based intervention based on tenets of self-determination theory. SELF-FIT aims to increase students' moderate-to-vigorous physical activity (MVPA) during physical education lessons, and enhance their autonomous motivation towards fitness activities. Using a cluster randomized controlled trial, we aim to examine the effects of the intervention on students' MVPA during school physical education. Secondary 2 students (approximately aged 14 years) from 26 classes in 26 different schools will be recruited. After baseline assessments, students will be randomized into either the experimental group or wait-list control group using a matched-pair randomization. Teachers allocated to the experimental group will attend two half-day workshops and deliver the SELF-FIT intervention for 8 weeks. The main intervention components include training teachers to teach in more need supportive ways, and conducting fitness exercises using a fitness dice with interchangeable faces. Other motivational components, such as playing music during classes, are also included. The primary outcome of the trial is students' MVPA during PE lessons. Secondary outcomes include students' leisure-time MVPA, perceived need support from teachers, need satisfaction, autonomous motivation towards physical education, intention to engage in physical activity, psychological well-being, and health-related fitness (cardiorespiratory and muscular fitness). Quantitative data will be analyzed using multilevel modeling approaches. Focus group interviews will also be conducted to assess students' perceptions of the intervention. The SELF-FIT intervention has been designed to improve students' health and well-being by using high-intensity activities in classes delivered by teachers who have been trained to be autonomy needs supportive. If successful, scalable interventions based on SELF-FIT could be applied in physical

  10. A simple sample size formula for analysis of covariance in cluster randomized trials.

    NARCIS (Netherlands)

    Teerenstra, S.; Eldridge, S.; Graff, M.J.; Hoop, E. de; Borm, G.F.

    2012-01-01

    For cluster randomized trials with a continuous outcome, the sample size is often calculated as if an analysis of the outcomes at the end of the treatment period (follow-up scores) would be performed. However, often a baseline measurement of the outcome is available or feasible to obtain. An

  11. Pair natural orbital and canonical coupled cluster reaction enthalpies involving light to heavy alkali and alkaline earth metals: the importance of sub-valence correlation

    KAUST Repository

    Minenkov, Yury; Bistoni, Giovanni; Riplinger, Christoph; Auer, Alexander A.; Neese, Frank; Cavallo, Luigi

    2017-01-01

    In this work, we tested canonical and domain based pair natural orbital coupled cluster methods (CCSD(T) and DLPNO-CCSD(T), respectively) for a set of 32 ligand exchange and association/dissociation reaction enthalpies involving ionic complexes

  12. Supportive supervision for volunteers to deliver reproductive health education: a cluster randomized trial.

    Science.gov (United States)

    Singh, Debra; Negin, Joel; Orach, Christopher Garimoi; Cumming, Robert

    2016-10-03

    Community Health Volunteers (CHVs) can be effective in improving pregnancy and newborn outcomes through community education. Inadequate supervision of CHVs, whether due to poor planning, irregular visits, or ineffective supervisory methods, is, however, recognized as a weakness in many programs. There has been little research on best practice supervisory or accompaniment models. From March 2014 to February 2015 a proof of concept study was conducted to compare training alone versus training and supportive supervision by paid CHWs (n = 4) on the effectiveness of CHVs (n = 82) to deliver education about pregnancy, newborn care, family planning and hygiene. The pair-matched cluster randomized trial was conducted in eight villages (four intervention and four control) in Budondo sub-county in Jinja, Uganda. Increases in desired behaviors were seen in both the intervention and control arms over the study period. Both arms showed high retention rates of CHVs (95 %). At 1 year follow-up there was a significantly higher prevalence of installed and functioning tippy taps for hand washing (p services. Supportive supervision involves creating a non-threatening, empowering environment in which both the CHV and the supervising CHW learn together and overcome obstacles that might otherwise demotivate the CHV. While the results seem promising for added value with supportive supervision for CHVs undertaking reproductive health activities, further research on a larger scale will be needed to substantiate the effect.

  13. Structure of 2,4-Diaminopyrimidine - Theobromine Alternate Base Pairs

    Science.gov (United States)

    Gengeliczki, Zsolt; Callahan, Michael P.; Kabelac, Martin; Rijs, Anouk M.; deVries, Mattanjah S.

    2011-01-01

    We report the structure of clusters of 2,4-diaminopyrimidine with 3,7-dimethylxanthine (theobromine) in the gas phase determined by IR-UV double resonance spectroscopy in both the near-IR and mid-IR regions in combination with ab initio computations. These clusters represent potential alternate nucleobase pairs, geometrically equivalent to guanine-cytosine. We have found the four lowest energy structures, which include the Watson-Crick base pairing motif. This Watson-Crick structure has not been observed by resonant two-photon ionization (R2PI) in the gas phase for the canonical DNA base pairs.

  14. A cluster randomized control trial to assess the impact of active learning on child activity, attention control, and academic outcomes: The Texas I-CAN trial.

    Science.gov (United States)

    Bartholomew, John B; Jowers, Esbelle M; Errisuriz, Vanessa L; Vaughn, Sharon; Roberts, Gregory

    2017-10-01

    Active learning is designed to pair physical activity with the teaching of academic content. This has been shown to be a successful strategy to increase physical activity and improve academic performance. The existing designs have confounded academic lessons with physical activity. As a result, it is impossible to determine if the subsequent improvement in academic performance is due to: (1) physical activity, (2) the academic content of the active learning, or (3) the combination of academic material taught through physical activity. The Texas I-CAN project is a 3-arm, cluster randomized control trial in which 28 elementary schools were assigned to either control, math intervention, or spelling intervention. As a result, each intervention condition serves as an unrelated content control for the other arm of the trial, allowing the impact of physical activity to be separated from the content. That is, schools that perform only active math lessons provide a content control for the spelling schools on spelling outcomes. This also calculated direct observations of attention and behavior control following periods of active learning. This design is unique in its ability to separate the impact of physical activity, in general, from the combination of physical activity and specific academic content. This, in combination with the ability to examine both proximal and distal outcomes along with measures of time on task will do much to guide the design of future, school-based interventions. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Recruitment to Online Therapies for Depression: Pilot Cluster Randomized Controlled Trial

    OpenAIRE

    Jones, Ray B; Goldsmith, Lesley; Hewson, Paul; Williams, Christopher J

    2013-01-01

    Background Raising awareness of online cognitive behavioral therapy (CBT) could benefit many people with depression, but we do not know how purchasing online advertising compares to placing free links from relevant local websites in increasing uptake. Objective To pilot a cluster randomized controlled trial (RCT) comparing purchase of Google AdWords with placing free website links in raising awareness of online CBT resources for depression in order to better understand research design issues....

  16. Point-of-care cluster randomized trial in stroke secondary prevention using electronic health records

    NARCIS (Netherlands)

    Dregan, Alex; van Staa, Tjeerd P; McDermott, Lisa; McCann, Gerard; Ashworth, Mark; Charlton, Judith; Wolfe, Charles D A; Rudd, Anthony; Yardley, Lucy; Gulliford, Martin C

    BACKGROUND AND PURPOSE: The aim of this study was to evaluate whether the remote introduction of electronic decision support tools into family practices improves risk factor control after first stroke. This study also aimed to develop methods to implement cluster randomized trials in stroke using

  17. Efficacy of iron-supplement bars to reduce anemia in urban Indian women: a cluster-randomized controlled trial.

    Science.gov (United States)

    Mehta, Rajvi; Platt, Alyssa C; Sun, Xizi; Desai, Mukesh; Clements, Dennis; Turner, Elizabeth L

    2017-03-01

    Background: India's high prevalence of iron-deficiency anemia has largely been attributed to the local diet consisting of nonheme iron, which has lower absorption than that of heme iron. Objective: We assessed the efficacy of the consumption of iron-supplement bars in raising hemoglobin concentrations and hematocrit percentages in anemic (hemoglobin concentration Indian women of reproductive age. Design: The Let's be Well Red study was a 90-d, pair-matched, cluster-randomized controlled trial. A total of 361 nonpregnant women (age 18-35 y) were recruited from 10 sites within Mumbai and Navi Mumbai, India. All participants received anemia education and a complete blood count (CBC). Random assignment of anemic participants to intervention and control arms occurred within 5 matched site-pairs. Intervention participants received 1 iron-supplement bar (containing 14 mg Fe)/d for 90 d, whereas control subjects received nothing. CBC tests were given at days 15, 45, and 90. Primary outcomes were 90-d changes from baseline in hemoglobin concentrations and hematocrit percentages. Linear mixed models and generalized estimating equations were used to model continuous and binary outcomes, respectively. Results: Of 179 anemic participants, 136 (76.0%) completed all follow-up assessments (65 intervention and 71 control participants). Baseline characteristics were comparable by arm. Mean hemoglobin and hematocrit increases after 90 d were greater for intervention than for control participants [1.4 g/dL (95% CI: 1.3, 1.6 g/dL) and 2.7% (95% CI: 2.2%, 3.2%), respectively]. The anemia prevalence at 90 d was lower for intervention (29.2%) than for control participants (98.6%) (OR: 0.007; 95% CI: 0.001, 0.04). Conclusions: The daily consumption of an iron-supplement bar leads to increased hemoglobin concentrations and hematocrit percentages and to a lower anemia prevalence in the target population with no reported side effects. This intervention is an attractive option to combat anemia

  18. Cluster-randomized xylitol toothpaste trial for early childhood caries prevention

    Science.gov (United States)

    Chi, Donald L.; Tut, Ohnmar K.; Milgrom, Peter

    2013-01-01

    Purpose We assessed the efficacy of supervised toothbrushing with xylitol toothpaste to prevent early childhood caries (ECC) and to reduce mutans streptococci (MS). Methods In this cluster-randomized efficacy trial, 4 Head Start classrooms in the Marshall Islands were randomly assigned to supervised toothbrushing with 1,400ppm/31% fluoride-xylitol (Epic Dental, Provo, UT) or 1,450ppm fluoride-sorbitol toothpaste (Colgate-Palmolive, New York, NY) (N=196 children, ages 4–5 yrs). We hypothesized no difference in efficacy between the two types of toothpaste. The primary outcome was primary molar d2-3mfs increment after 6 mos. A single examiner was blinded to classroom assignments. Two classrooms were assigned to the fluoride-xylitol group (85 children) and 2 classrooms to the fluoride-sorbitol group (83 children). The child-level analyses accounted for clustering. Results There was no difference between the two groups in baseline or end-of-trial mean d2-3mfs. The mean d2-3mfs increment was greater in the fluoride-xylitol group compared to the fluoride-sorbitol group (2.5 and 1.4 d2-3mfs, respectively), but the difference was not significant (95% CI:−0.17, 2.37;P=0.07). No adverse effects were reported. Conclusion After 6 mos, brushing with a low strength xylitol/fluoride toothpaste is no more efficacious in reducing ECC than a fluoride only toothpaste in a high caries risk child population. PMID:24709430

  19. Cluster-randomized xylitol toothpaste trial for early childhood caries prevention.

    Science.gov (United States)

    Chi, Donald L; Tut, Ohnmar; Milgrom, Peter

    2014-01-01

    The purpose of this study was to assess the efficacy of supervised tooth-brushing with xylitol toothpaste to prevent early childhood caries (ECC) and reduce mutans streptococci. In this cluster-randomized efficacy trial, 196 four- to five-year-old children in four Head Start classrooms in the Marshall Islands were randomly assigned to supervised toothbrushing with 1,400 ppm/31 percent fluoride xylitol or 1,450 ppm fluoride sorbitol toothpaste. We hypothesized that there would be no difference in efficacy between the two types of toothpaste. The primary outcome was the surface-level primary molar caries increment (d(2-3)mfs) after six months. A single examiner was blinded to classroom assignments. Two classrooms were assigned to the fluoride-xylitol group (85 children), and two classrooms were assigned to the fluoride-sorbitol group (83 children). The child-level analyses accounted for clustering. There was no difference between the two groups in baseline or end-of-trial mean d(2-3)mfs. The mean d(2-3)mfs increment was greater in the fluoride-xylitol group compared to the fluoride-sorbitol group (2.5 and 1.4 d(2-3)mfs, respectively), but the difference was not significant (95% confidence interval: -0.17, 2.37; P=.07). No adverse effects were reported. After six months, brushing with a low-strength xylitol/fluoride tooth-paste is no more efficacious in reducing ECC than a fluoride-only toothpaste in a high caries-risk child population.

  20. Role of the HSPA9/HSC20 chaperone pair in promoting directional human iron-sulfur cluster exchange involving monothiol glutaredoxin 5.

    Science.gov (United States)

    Olive, Joshua A; Cowan, J A

    2018-07-01

    Iron‑sulfur clusters are essential cofactors found across all domains of life. Their assembly and transfer are accomplished by highly conserved protein complexes and partners. In eukaryotes a [2Fe-2S] cluster is first assembled in the mitochondria on the iron‑sulfur cluster scaffold protein ISCU in tandem with iron, sulfide, and electron donors. Current models suggest that a chaperone pair interacts with a cluster-bound ISCU to facilitate cluster transfer to a monothiol glutaredoxin. In humans this protein is glutaredoxin 5 (GLRX5) and the cluster can then be exchanged with a variety of target apo proteins. By use of circular dichroism spectroscopy, the kinetics of cluster exchange reactivity has been evaluated for human GLRX5 with a variety of cluster donor and acceptor partners, and the role of chaperones determined for several of these. In contrast to the prokaryotic model, where heat-shock type chaperone proteins HscA and HscB are required for successful and efficient transfer of a [2Fe-2S] cluster from the ISCU scaffold to a monothiol glutaredoxin. However, in the human system the chaperone homologs, HSPA9 and HSC20, are not necessary for human ISCU to promote cluster transfer to GLRX5, and appear to promote the reverse transfer. Cluster exchange with the human iron‑sulfur cluster carrier protein NFU1 and ferredoxins (FDX's), and the role of chaperones, has also been evaluated, demonstrating in certain cases control over the directionality of cluster transfer. In contrast to other prokaryotic and eukaryotic organisms, NFU1 is identified as a more likely physiological donor of [2Fe-2S] cluster to human GLRX5 than ISCU. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Structuring communication relationships for interprofessional teamwork (SCRIPT): a cluster randomized controlled trial

    OpenAIRE

    Zwarenstein, Merrick; Reeves, Scott; Russell, Ann; Kenaszchuk, Chris; Conn, Lesley Gotlib; Miller, Karen-Lee; Lingard, Lorelei; Thorpe, Kevin E

    2007-01-01

    Abstract Background Despite a burgeoning interest in using interprofessional approaches to promote effective collaboration in health care, systematic reviews find scant evidence of benefit. This protocol describes the first cluster randomized controlled trial (RCT) to design and evaluate an intervention intended to improve interprofessional collaborative communication and patient-centred care. Objectives The objective is to evaluate the effects of a four-component, hospital-based staff commun...

  2. A new mother-child play activity program to decrease parenting stress and improve child cognitive abilities: a cluster randomized controlled trial.

    Science.gov (United States)

    Tachibana, Yoshiyuki; Fukushima, Ai; Saito, Hitomi; Yoneyama, Satoshi; Ushida, Kazuo; Yoneyama, Susumu; Kawashima, Ryuta

    2012-01-01

    We propose a new play activity intervention program for mothers and children. Our interdisciplinary program integrates four fields of child-related sciences: neuroscience, preschool pedagogy, developmental psychology, and child and maternal psychiatry. To determine the effect of this intervention on child and mother psychosocial problems related to parenting stress and on the children's cognitive abilities, we performed a cluster randomized controlled trial. Participants were 238 pairs of mothers and typically developing preschool children (ages 4-6 years old) from Wakakusa kindergarten in Japan. The pairs were asked to play at home for about 10 min a day, 5 days a week for 3 months. Participants were randomly assigned to the intervention or control group by class unit. The Parenting Stress Index (PSI) (for mothers), the Goodenough Draw-a-Man intelligence test (DAM), and the new S-S intelligence test (NS-SIT) (for children) were administered prior to and 3 months after the intervention period. Pre-post changes in test scores were compared between the groups using a linear mixed-effects model analysis. The primary outcomes were the Total score on the child domain of the PSI (for child psychosocial problems related to parenting stress), Total score on the parent domain of the PSI (for maternal psychosocial problems related to parenting stress), and the score on the DAM (for child cognitive abilities). The results of the PSI suggested that the program may reduce parenting stress. The results of the cognitive tests suggested that the program may improve the children's fluid intelligence, working memory, and processing speed. Our intervention program may ameliorate the children's psychosocial problems related to parenting stress and increase their cognitive abilities. UMIN Clinical Trials Registry UMIN000002265.

  3. Increasing students’ physical activity during school physical education: rationale and protocol for the SELF-FIT cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Amy S. Ha

    2017-07-01

    Full Text Available Abstract Background The Self-determined Exercise and Learning For FITness (SELF-FIT is a multi-component school-based intervention based on tenets of self-determination theory. SELF-FIT aims to increase students’ moderate-to-vigorous physical activity (MVPA during physical education lessons, and enhance their autonomous motivation towards fitness activities. Using a cluster randomized controlled trial, we aim to examine the effects of the intervention on students’ MVPA during school physical education. Methods Secondary 2 students (approximately aged 14 years from 26 classes in 26 different schools will be recruited. After baseline assessments, students will be randomized into either the experimental group or wait-list control group using a matched-pair randomization. Teachers allocated to the experimental group will attend two half-day workshops and deliver the SELF-FIT intervention for 8 weeks. The main intervention components include training teachers to teach in more need supportive ways, and conducting fitness exercises using a fitness dice with interchangeable faces. Other motivational components, such as playing music during classes, are also included. The primary outcome of the trial is students’ MVPA during PE lessons. Secondary outcomes include students’ leisure-time MVPA, perceived need support from teachers, need satisfaction, autonomous motivation towards physical education, intention to engage in physical activity, psychological well-being, and health-related fitness (cardiorespiratory and muscular fitness. Quantitative data will be analyzed using multilevel modeling approaches. Focus group interviews will also be conducted to assess students’ perceptions of the intervention. Discussion The SELF-FIT intervention has been designed to improve students’ health and well-being by using high-intensity activities in classes delivered by teachers who have been trained to be autonomy needs supportive. If successful, scalable

  4. Assessment of community-level effects of intermittent preventive treatment for malaria in schoolchildren in Jinja, Uganda (START-IPT trial): a cluster-randomised trial.

    Science.gov (United States)

    Staedke, Sarah G; Maiteki-Sebuguzi, Catherine; Rehman, Andrea M; Kigozi, Simon P; Gonahasa, Samuel; Okiring, Jaffer; Lindsay, Steve W; Kamya, Moses R; Chandler, Clare I R; Dorsey, Grant; Drakeley, Chris

    2018-06-01

    Intermittent preventive treatment (IPT) is a well established malaria control intervention. Evidence that delivering IPT to schoolchildren could provide community-level benefits is limited. We did a cluster-randomised controlled trial to assess the effect of IPT of primary schoolchildren with dihydroartemisinin-piperaquine (DP) on indicators of malaria transmission in the community, in Jinja, Uganda. We included 84 clusters, each comprising one primary school and the 100 closest available households. The clusters were randomly assigned 1:1 to receive IPT with DP or standard care (control) by restricted randomisation to ensure balance by geography and school type. Children in intervention schools received IPT monthly for up to six rounds (June to December, 2014). We did cross-sectional community surveys in randomly selected households at baseline and in January to April, 2015, during which we measured participants' temperatures and obtained finger-prick blood smears for measurement of parasite prevalence by microscopy. We also did entomological surveys 1 night per month in households from 20 randomly selected IPT and 20 control clusters. The primary trial outcome was parasite prevalence in the final community survey. The primary entomological survey outcome was the annual entomological inoculation rate (aEIR) from July, 2014, to April, 2015. This trial is registered at ClinicalTrials.gov, number NCT02009215. Among 23 280 students registered in the 42 intervention schools, 10 079 (43%) aged 5-20 years were enrolled and received at least one dose of DP. 9286 (92%) of 10 079 received at least one full course of DP (three doses). Community-level parasite prevalence was lower in the intervention clusters than in the control clusters (19% vs 23%, adjusted risk ratio 0·85, 95% CI 0·73-1·00, p=0·05). The aEIR was lower in the intervention group than in the control group, but not significantly so (10·1 vs 15·2 infective bites per person, adjusted incidence rate

  5. Structuring communication relationships for interprofessional teamwork (SCRIPT: a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Kenaszchuk Chris

    2007-09-01

    Full Text Available Abstract Background Despite a burgeoning interest in using interprofessional approaches to promote effective collaboration in health care, systematic reviews find scant evidence of benefit. This protocol describes the first cluster randomized controlled trial (RCT to design and evaluate an intervention intended to improve interprofessional collaborative communication and patient-centred care. Objectives The objective is to evaluate the effects of a four-component, hospital-based staff communication protocol designed to promote collaborative communication between healthcare professionals and enhance patient-centred care. Methods The study is a multi-centre mixed-methods cluster randomized controlled trial involving twenty clinical teaching teams (CTTs in general internal medicine (GIM divisions of five Toronto tertiary-care hospitals. CTTs will be randomly assigned either to receive an intervention designed to improve interprofessional collaborative communication, or to continue usual communication practices. Non-participant naturalistic observation, shadowing, and semi-structured, qualitative interviews were conducted to explore existing patterns of interprofessional collaboration in the CTTs, and to support intervention development. Interviews and shadowing will continue during intervention delivery in order to document interactions between the intervention settings and adopters, and changes in interprofessional communication. The primary outcome is the rate of unplanned hospital readmission. Secondary outcomes are length of stay (LOS; adherence to evidence-based prescription drug therapy; patients' satisfaction with care; self-report surveys of CTT staff perceptions of interprofessional collaboration; and frequency of calls to paging devices. Outcomes will be compared on an intention-to-treat basis using adjustment methods appropriate for data from a cluster randomized design. Discussion Pre-intervention qualitative analysis revealed that a

  6. A pilot cluster randomized controlled trial of structured goal-setting following stroke.

    Science.gov (United States)

    Taylor, William J; Brown, Melanie; William, Levack; McPherson, Kathryn M; Reed, Kirk; Dean, Sarah G; Weatherall, Mark

    2012-04-01

    To determine the feasibility, the cluster design effect and the variance and minimal clinical importance difference in the primary outcome in a pilot study of a structured approach to goal-setting. A cluster randomized controlled trial. Inpatient rehabilitation facilities. People who were admitted to inpatient rehabilitation following stroke who had sufficient cognition to engage in structured goal-setting and complete the primary outcome measure. Structured goal elicitation using the Canadian Occupational Performance Measure. Quality of life at 12 weeks using the Schedule for Individualised Quality of Life (SEIQOL-DW), Functional Independence Measure, Short Form 36 and Patient Perception of Rehabilitation (measuring satisfaction with rehabilitation). Assessors were blinded to the intervention. Four rehabilitation services and 41 patients were randomized. We found high values of the intraclass correlation for the outcome measures (ranging from 0.03 to 0.40) and high variance of the SEIQOL-DW (SD 19.6) in relation to the minimally importance difference of 2.1, leading to impractically large sample size requirements for a cluster randomized design. A cluster randomized design is not a practical means of avoiding contamination effects in studies of inpatient rehabilitation goal-setting. Other techniques for coping with contamination effects are necessary.

  7. Effect of village-wide use of long-lasting insecticidal nets on visceral Leishmaniasis vectors in India and Nepal: a cluster randomized trial.

    Science.gov (United States)

    Picado, Albert; Das, Murari L; Kumar, Vijay; Kesari, Shreekant; Dinesh, Diwakar S; Roy, Lalita; Rijal, Suman; Das, Pradeep; Rowland, Mark; Sundar, Shyam; Coosemans, Marc; Boelaert, Marleen; Davies, Clive R

    2010-01-26

    Visceral leishmaniasis (VL) control in the Indian subcontinent is currently based on case detection and treatment, and on vector control using indoor residual spraying (IRS). The use of long-lasting insecticidal nets (LN) has been postulated as an alternative or complement to IRS. Here we tested the impact of comprehensive distribution of LN on the density of Phlebotomus argentipes in VL-endemic villages. A cluster-randomized controlled trial with household P. argentipes density as outcome was designed. Twelve clusters from an ongoing LN clinical trial--three intervention and three control clusters in both India and Nepal--were selected on the basis of accessibility and VL incidence. Ten houses per cluster selected on the basis of high pre-intervention P. argentipes density were monitored monthly for 12 months after distribution of LN using CDC light traps (LT) and mouth aspiration methods. Ten cattle sheds per cluster were also monitored by aspiration. A random effect linear regression model showed that the cluster-wide distribution of LNs significantly reduced the P. argentipes density/house by 24.9% (95% CI 1.80%-42.5%) as measured by means of LTs. The ongoing clinical trial, designed to measure the impact of LNs on VL incidence, will confirm whether LNs should be adopted as a control strategy in the regional VL elimination programs. The entomological evidence described here provides some evidence that LNs could be usefully deployed as part of the VL control program. ClinicalTrials.gov CT-2005-015374.

  8. Planck intermediate results: VIII. Filaments between interacting clusters

    DEFF Research Database (Denmark)

    Bartlett, J.G.; Cardoso, J.-F.; Castex, G.

    2013-01-01

    of a fraction of these missing baryons between pairs of galaxy clusters. Methods. Cluster pairs are good candidates for searching for the hotter and denser phase of the intergalactic medium (which is more easily observed through the SZ effect). Using an X-ray catalogue of clusters and the Planck data, we...

  9. A cluster-randomised trial of a multifaceted quality improvement intervention in Brazilian intensive care units (Checklist-ICU trial): statistical analysis plan.

    Science.gov (United States)

    Damiani, Lucas P; Cavalcanti, Alexandre B; Moreira, Frederico R; Machado, Flavia; Bozza, Fernando A; Salluh, Jorge I F; Campagnucci, Valquiria P; Normilio-Silva, Karina; Chiattone, Viviane C; Angus, Derek C; Berwanger, Otavio; Chou H Chang, Chung-

    2015-06-01

    The Checklist During Multidisciplinary Visits for Reduction of Mortality in Intensive Care Units (Checklist- ICU) trial is a pragmatic, two-arm, cluster-randomised trial involving 118 intensive care units in Brazil, with the primary objective of determining if a multifaceted qualityimprovement intervention with a daily checklist, definition of daily care goals during multidisciplinary daily rounds and clinician prompts can reduce inhospital mortality. To describe our trial statistical analysis plan (SAP). This is an ongoing trial conducted in two phases. In the preparatory observational phase, we collect three sets of baseline data: ICU characteristics; patient characteristics, processes of care and outcomes; and completed safety attitudes questionnaires (SAQs). In the randomised phase, ICUs are assigned to the experimental or control arms and we collect patient data and repeat the SAQ. Our SAP includes the prespecified model for the primary and secondary outcome analyses, which account for the cluster-randomised design and availability of baseline data. We also detail the multiple mediation models that we will use to assess our secondary hypothesis (that the effect of the intervention on inhospital mortality is mediated not only through care processes targeted by the checklist, but also through changes in safety culture). We describe our approach to sensitivity and subgroup analyses and missing data. We report our SAP before closing our study database and starting analysis. We anticipate that this should prevent analysis bias and enhance the utility of results.

  10. Hospital recruitment for a pragmatic cluster-randomized clinical trial: Lessons learned from the COMPASS study.

    Science.gov (United States)

    Johnson, Anna M; Jones, Sara B; Duncan, Pamela W; Bushnell, Cheryl D; Coleman, Sylvia W; Mettam, Laurie H; Kucharska-Newton, Anna M; Sissine, Mysha E; Rosamond, Wayne D

    2018-01-26

    Pragmatic randomized clinical trials are essential to determine the effectiveness of interventions in "real-world" clinical practice. These trials frequently use a cluster-randomized methodology, with randomization at the site level. Despite policymakers' increased interest in supporting pragmatic randomized clinical trials, no studies to date have reported on the unique recruitment challenges faced by cluster-randomized pragmatic trials. We investigated key challenges and successful strategies for hospital recruitment in the Comprehensive Post-Acute Stroke Services (COMPASS) study. The COMPASS study is designed to compare the effectiveness of the COMPASS model versus usual care in improving functional outcomes, reducing the numbers of hospital readmissions, and reducing caregiver strain for patients discharged home after stroke or transient ischemic attack. This model integrates early supported discharge planning with transitional care management, including nurse-led follow-up phone calls after 2, 30, and 60 days and an in-person clinic visit at 7-14 days involving a functional assessment and neurological examination. We present descriptive statistics of the characteristics of successfully recruited hospitals compared with all eligible hospitals, reasons for non-participation, and effective recruitment strategies. We successfully recruited 41 (43%) of 95 eligible North Carolina hospitals. Leading, non-exclusive reasons for non-participation included: insufficient staff or financial resources (n = 33, 61%), lack of health system support (n = 16, 30%), and lack of support of individual decision-makers (n = 11, 20%). Successful recruitment strategies included: building and nurturing relationships, engaging team members and community partners with a diverse skill mix, identifying gatekeepers, finding mutually beneficial solutions, having a central institutional review board, sharing published pilot data, and integrating contracts and review board

  11. Fit 5 Kids TV reduction program for Latino preschoolers: A cluster randomized controlled trial

    Science.gov (United States)

    Reducing Latino preschoolers' TV viewing is needed to reduce their risk of obesity and other chronic diseases. This study's objective was to evaluate the Fit 5 Kids (F5K) TV reduction program's impact on Latino preschooler's TV viewing. The study design was a cluster randomized controlled trial (RCT...

  12. Process evaluation of a cluster-randomised trial testing a pressure ulcer prevention care bundle: a mixed-methods study.

    Science.gov (United States)

    Roberts, Shelley; McInnes, Elizabeth; Bucknall, Tracey; Wallis, Marianne; Banks, Merrilyn; Chaboyer, Wendy

    2017-02-13

    As pressure ulcers contribute to significant patient burden and increased health care costs, their prevention is a clinical priority. Our team developed and tested a complex intervention, a pressure ulcer prevention care bundle promoting patient participation in care, in a cluster-randomised trial. The UK Medical Research Council recommends process evaluation of complex interventions to provide insight into why they work or fail and how they might be improved. This study aimed to evaluate processes underpinning implementation of the intervention and explore end-users' perceptions of it, in order to give a deeper understanding of its effects. A pre-specified, mixed-methods process evaluation was conducted as an adjunct to the main trial, guided by a framework for process evaluation of cluster-randomised trials. Data was collected across eight Australian hospitals but mainly focused on the four intervention hospitals. Quantitative and qualitative data were collected across the evaluation domains: recruitment, reach, intervention delivery and response to intervention, at both cluster and individual patient level. Quantitative data were analysed using descriptive and inferential statistics. Qualitative data were analysed using thematic analysis. In the context of the main trial, which found a 42% reduction in risk of pressure ulcer with the intervention that was not significant after adjusting for clustering and covariates, this process evaluation provides important insights. Recruitment and reach among clusters and individuals was high, indicating that patients, nurses and hospitals are willing to engage with a pressure ulcer prevention care bundle. Of 799 intervention patients in the trial, 96.7% received the intervention, which took under 10 min to deliver. Patients and nurses accepted the care bundle, recognising benefits to it and describing how it enabled participation in pressure ulcer prevention (PUP) care. This process evaluation found no major failures

  13. Factored Translation with Unsupervised Word Clusters

    DEFF Research Database (Denmark)

    Rishøj, Christian; Søgaard, Anders

    2011-01-01

    Unsupervised word clustering algorithms — which form word clusters based on a measure of distributional similarity — have proven to be useful in providing beneficial features for various natural language processing tasks involving supervised learning. This work explores the utility of such word...... clusters as factors in statistical machine translation. Although some of the language pairs in this work clearly benefit from the factor augmentation, there is no consistent improvement in translation accuracy across the board. For all language pairs, the word clusters clearly improve translation for some...... proportion of the sentences in the test set, but has a weak or even detrimental effect on the rest. It is shown that if one could determine whether or not to use a factor when translating a given sentence, rather substantial improvements in precision could be achieved for all of the language pairs evaluated...

  14. Design and protocol of the weight loss lottery- a cluster randomized trial.

    Science.gov (United States)

    van der Swaluw, Koen; Lambooij, Mattijs S; Mathijssen, Jolanda J P; Schipper, Maarten; Zeelenberg, Marcel; Polder, Johan J; Prast, Henriëtte M

    2016-07-01

    People often intend to exercise but find it difficult to attend their gyms on a regular basis. At times, people seek and accept deadlines with consequences to realize their own goals (i.e. commitment devices). The aim of our cluster randomized controlled trial is to test whether a lottery-based commitment device can promote regular gym attendance. The winners of the lottery always get feedback on the outcome but can only claim their prize if they attended their gyms on a regular basis. In this paper we present the design and baseline characteristics of a three-arm trial which is performed with 163 overweight participants in six in-company fitness centers in the Netherlands. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Can group-based reassuring information alter low back pain behavior? A cluster-randomized controlled trial

    DEFF Research Database (Denmark)

    Frederiksen, Pernille; Indahl, Aage; Andersen, Lars L

    2017-01-01

    -randomized controlled trial. METHODS: Publically employed workers (n = 505) from 11 Danish municipality centers were randomized at center-level (cluster) to either intervention (two 1-hour group-based talks at the workplace) or control. The talks provided reassuring information together with a simple non...

  16. A Novel Clustering Model Based on Set Pair Analysis for the Energy Consumption Forecast in China

    Directory of Open Access Journals (Sweden)

    Mingwu Wang

    2014-01-01

    Full Text Available The energy consumption forecast is important for the decision-making of national economic and energy policies. But it is a complex and uncertainty system problem affected by the outer environment and various uncertainty factors. Herein, a novel clustering model based on set pair analysis (SPA was introduced to analyze and predict energy consumption. The annual dynamic relative indicator (DRI of historical energy consumption was adopted to conduct a cluster analysis with Fisher’s optimal partition method. Combined with indicator weights, group centroids of DRIs for influence factors were transferred into aggregating connection numbers in order to interpret uncertainty by identity-discrepancy-contrary (IDC analysis. Moreover, a forecasting model based on similarity to group centroid was discussed to forecast energy consumption of a certain year on the basis of measured values of influence factors. Finally, a case study predicting China’s future energy consumption as well as comparison with the grey method was conducted to confirm the reliability and validity of the model. The results indicate that the method presented here is more feasible and easier to use and can interpret certainty and uncertainty of development speed of energy consumption and influence factors as a whole.

  17. The Quality Initiative in Rectal Cancer (QIRC trial: study protocol of a cluster randomized controlled trial in surgery

    Directory of Open Access Journals (Sweden)

    Thabane Lehana

    2008-02-01

    Full Text Available Abstract Background Two unfortunate outcomes for patients treated surgically for rectal cancer are placement of a permanent colostomy and local tumor recurrence. Total mesorectal excision is a new technique for rectal cancer surgery that can lead to improved patient outcomes. We describe a cluster randomized controlled trial that is testing if the above patient outcomes can be improved through a knowledge translation strategy called the Quality Initiative in Rectal Cancer (QIRC strategy. The strategy is designed to optimize the use of total mesorectal excision techniques. Methods and Design Hospitals were randomized to the QIRC strategy (experimental group versus normal practice environment (control group. Participating hospitals, and the respective surgeon group operating in them, are from Ontario, Canada and have an annual procedure volume for major rectal cancer resections of 15 or greater. Patients were eligible if they underwent major rectal surgery for a diagnosis of primary rectal cancer. The surgeon-directed QIRC interventions included a workshop, use of opinion leaders, operative demonstrations, a post-operative questionnaire, and, audit and feedback. For an operative demonstration participating surgeons invited a study team surgeon to assist them with a case of rectal cancer surgery. The intent was to demonstrate total mesorectal excision techniques. Control arm surgeons received no intervention. Sample size calculations were two-sided, considered the clustering of data at the hospital level, and were driven by requirements for the outcome local recurrence. To detect an improvement in local recurrence from 20% to 8% with confidence we required 16 hospitals and 672 patients – 8 hospitals and 336 patients in each arm. Outcomes data are collected via chart review for at least 30 months after surgery. Analyses will use an intention-to-treat principle and will consider the clustering of data. Data collection will be complete by the end of

  18. Clustering at high redshifts

    International Nuclear Information System (INIS)

    Shaver, P.A.

    1986-01-01

    Evidence for clustering of and with high-redshift QSOs is discussed. QSOs of different redshifts show no clustering, but QSOs of similar redshifts appear to be clustered on a scale comparable to that of galaxies at the present epoch. In addition, spectroscopic studies of close pairs of QSOs indicate that QSOs are surrounded by a relatively high density of absorbing matter, possibly clusters of galaxies

  19. Text messaging reminders for influenza vaccine in primary care: protocol for a cluster randomised controlled trial (TXT4FLUJAB).

    Science.gov (United States)

    Herrett, Emily; van Staa, Tjeerd; Free, Caroline; Smeeth, Liam

    2014-05-02

    The UK government recommends that at least 75% of people aged under 64 with certain conditions receive an annual influenza vaccination. Primary care practices often fall short of this target and strategies to increase vaccine uptake are required. Text messaging reminders are already used in 30% of practices to remind patients about vaccination, but there has been no trial addressing their effectiveness in increasing influenza vaccine uptake in the UK. The aims of the study are (1) to develop the methodology for conducting cluster randomised trials of text messaging interventions utilising routine electronic health records and (2) to assess the effectiveness of using a text messaging influenza vaccine reminder in achieving an increase in influenza vaccine uptake in patients aged 18-64 with chronic conditions, compared with standard care. This cluster randomised trial will recruit general practices across three settings in English primary care (Clinical Practice Research Datalink, ResearchOne and London iPLATO text messaging software users) and randomise them to either standard care or a text messaging campaign to eligible patients. Flu vaccine uptake will be ascertained using routinely collected, anonymised electronic patient records. This protocol outlines the proposed study design and analysis methods. This study will determine the effectiveness of text messaging vaccine reminders in primary care in increasing influenza vaccine uptake, and will strengthen the methodology for using electronic health records in cluster randomised trials of text messaging interventions. This trial was approved by the Surrey Borders Ethics Committee (13/LO/0872). The trial results will be disseminated at national conferences and published in a peer-reviewed medical journal. The results will also be distributed to the Primary Care Research Network and to all participating general practices. This study is registered at controlled-trials.com ISRCTN48840025, July 2013.

  20. Nurse-coordinated multidisciplinary, family-based cardiovascular disease prevention programme (EUROACTION) for patients with coronary heart disease and asymptomatic individuals at high risk of cardiovascular disease: a paired, cluster-randomised controlled trial.

    Science.gov (United States)

    Wood, D A; Kotseva, K; Connolly, S; Jennings, C; Mead, A; Jones, J; Holden, A; De Bacquer, D; Collier, T; De Backer, G; Faergeman, O

    2008-06-14

    Our aim was to investigate whether a nurse-coordinated multidisciplinary, family-based preventive cardiology programme could improve standards of preventive care in routine clinical practice. In a matched, cluster-randomised, controlled trial in eight European countries, six pairs of hospitals and six pairs of general practices were assigned to an intervention programme (INT) or usual care (UC) for patients with coronary heart disease or those at high risk of developing cardiovascular disease. The primary endpoints-measured at 1 year-were family-based lifestyle change; management of blood pressure, lipids, and blood glucose to target concentrations; and prescription of cardioprotective drugs. Analysis was by intention to treat. The trial is registered as ISRCTN 71715857. 1589 and 1499 patients with coronary heart disease in hospitals and 1189 and 1128 at high risk were assigned to INT and UC, respectively. In patients with coronary heart disease who smoked in the month before the event, 136 (58%) in the INT and 154 (47%) in the UC groups did not smoke 1 year afterwards (difference in change 10.4%, 95% CI -0.3 to 21.2, p=0.06). Reduced consumption of saturated fat (196 [55%] vs 168 [40%]; 17.3%, 6.4 to 28.2, p=0.009), and increased consumption of fruit and vegetables (680 [72%] vs 349 [35%]; 37.3%, 18.1 to 56.5, p=0.004), and oily fish (156 [17%] vs 81 [8%]; 8.9%, 0.3 to 17.5, p=0.04) at 1 year were greatest in the INT group. High-risk individuals and partners showed changes only for fruit and vegetables (p=0.005). Blood-pressure target of less than 140/90 mm Hg was attained by both coronary (615 [65%] vs 547 [55%]; 10.4%, 0.6 to 20.2, p=0.04) and high-risk (586 [58%] vs 407 [41%]; 16.9%, 2.0 to 31.8, p=0.03) patients in the INT groups. Achievement of total cholesterol of less than 5 mmol/L did not differ between groups, but in high-risk patients the difference in change from baseline to 1 year was 12.7% (2.4 to 23.0, p=0.02) in favour of INT. In the hospital group

  1. Sample size calculations for cluster randomised crossover trials in Australian and New Zealand intensive care research.

    Science.gov (United States)

    Arnup, Sarah J; McKenzie, Joanne E; Pilcher, David; Bellomo, Rinaldo; Forbes, Andrew B

    2018-06-01

    The cluster randomised crossover (CRXO) design provides an opportunity to conduct randomised controlled trials to evaluate low risk interventions in the intensive care setting. Our aim is to provide a tutorial on how to perform a sample size calculation for a CRXO trial, focusing on the meaning of the elements required for the calculations, with application to intensive care trials. We use all-cause in-hospital mortality from the Australian and New Zealand Intensive Care Society Adult Patient Database clinical registry to illustrate the sample size calculations. We show sample size calculations for a two-intervention, two 12-month period, cross-sectional CRXO trial. We provide the formulae, and examples of their use, to determine the number of intensive care units required to detect a risk ratio (RR) with a designated level of power between two interventions for trials in which the elements required for sample size calculations remain constant across all ICUs (unstratified design); and in which there are distinct groups (strata) of ICUs that differ importantly in the elements required for sample size calculations (stratified design). The CRXO design markedly reduces the sample size requirement compared with the parallel-group, cluster randomised design for the example cases. The stratified design further reduces the sample size requirement compared with the unstratified design. The CRXO design enables the evaluation of routinely used interventions that can bring about small, but important, improvements in patient care in the intensive care setting.

  2. E-learning or educational leaflet: does it make a difference in oral health promotion? A clustered randomized trial.

    Science.gov (United States)

    Al Bardaweel, Susan; Dashash, Mayssoon

    2018-05-10

    The early recognition of technology together with great ability to use computers and smart systems have promoted researchers to investigate the possibilities of utilizing technology for improving health care in children. The aim of this study was to compare between the traditional educational leaflets and E-applications in improving oral health knowledge, oral hygiene and gingival health in schoolchildren of Damascus city, Syria. A clustered randomized controlled trial at two public primary schools was performed. About 220 schoolchildren aged 10-11 years were included in this study and grouped into two clusters. Children in Leaflet cluster received oral health education through leaflets, while children in E-learning cluster received oral health education through an E-learning program. A questionnaire was designed to register information related to oral health knowledge and to record Plaque and Gingival indices. Questionnaire administration and clinical assessment were undertaken at baseline, 6 and at 12 weeks of oral health education. Data was analysed using one way repeated measures ANOVA, post hoc Bonferroni test and independent samples t-test. Leaflet cluster (107 participants) had statistically significant better oral health knowledge than E-learning cluster (104 participants) at 6 weeks (P E-learning cluster:100 participants). The mean knowledge gain compared to baseline was higher in Leaflet cluster than in E-learning cluster. A significant reduction in the PI means at 6 weeks and 12 weeks was observed in both clusters (P E-learning cluster at 6 weeks (P E-learning cluster at 6 weeks (P < 0.05) and 12 weeks (P < 0.05). Traditional educational leaflets are an effective tool in the improvement of both oral health knowledge as well as clinical indices of oral hygiene and care among Syrian children. Leaflets can be used in school-based oral health education for a positive outcome. Australian New Zealand Clinical Trials Registry ( ACTRN

  3. Paired quasars near NGC 2639: Evidence for quasars in superclusters

    International Nuclear Information System (INIS)

    Ford, H.; Ciardullo, R.; Harms, R.

    1983-01-01

    Arp found 10 quasars near a low-redshift galaxy 27' SSE of NGC 2639. Six of the quasars can be grouped into three redshift pairs which align across the anonymous galaxy. The large number of quasars and pairings could show an association with the low-redshift galaxy, or alternatively, might be due to superclusters seen along the line of sight. We tested the latter hypothesis by using deep, red-sensitive Lick 3 m prime focus plates to search for a supercluster associated with the z = 0.3 quasar pair. The plates show extended nebulosity associated with the quasar U10 (thetaapprox.7'', or 20 kpc at z = 0.3) and a richness class 1, Bautz-Morgan type III cluster 4' NW of U10. A spectrum of one the cluster's brightest galaxies gives z = 0.34, suggesting that the cluster and quasar are unassociated. We obtained spectra of eight of the quasars and find that (i) two of the quasars have very strong absorption shortward of Lyα, and (ii) two of Arp's redshifts (including one which Arp considered uncertain) are incorrect. Our redshifts break two of the redshift pairs, including the pair at z = 0.3. We use the redshift distribution of optically selected quasars to argue that the third pair has no statistical significance, and conclude that there is no basis for associating the quasars with the low-redshift anonymous galaxy. The disappearance of the redshift pairs vitiates the possibility of testing the paired-quasars-in-superclusters hypothesis in the NGC 2639 field

  4. Increasing physical activity in young primary school children-it's child's play: A cluster randomised controlled trial

    NARCIS (Netherlands)

    Engelen, L.; Bundy, A.C.; Naughton, G.; Simpson, J.M.; Bauman, A.; Ragen, J.; Baur, L.; Wyver, S.; Tranter, P.; Niehues, A.; Schiller, W.; Perry, G.; Jessup, G.; van der Ploeg, H.P.

    2013-01-01

    Objective: To explore the effects of an innovative school-based intervention for increasing physical activity. Methods: 226 children (5-7. years old) randomly selected from 12 Australian primary schools were recruited to a cluster randomised trial with schools randomly allocated to intervention or

  5. Mitigating Diseases Transmitted by Aedes Mosquitoes: A Cluster-Randomised Trial of Permethrin-Impregnated School Uniforms.

    Directory of Open Access Journals (Sweden)

    Pattamaporn Kittayapong

    2017-01-01

    Full Text Available Viral diseases transmitted via Aedes mosquitoes are on the rise, such as Zika, dengue, and chikungunya. Novel tools to mitigate Aedes mosquitoes-transmitted diseases are urgently needed. We tested whether commercially insecticide-impregnated school uniforms can reduce dengue incidence in school children.We designed a cluster-randomised controlled trial in Thailand. The primary endpoint was laboratory-confirmed dengue infections. Secondary endpoints were school absenteeism; and impregnated uniforms' 1-hour knock-down and 24 hour mosquito mortality as measured by standardised WHOPES bioassay cone tests at baseline and after repeated washing. Furthermore, entomological assessments inside classrooms and in outside areas of schools were conducted.We enrolled 1,811 pupils aged 6-17 from 5 intervention and 5 control schools. Paired serum samples were obtained from 1,655 pupils. In the control schools, 24/641 (3.7% and in the intervention schools 33/1,014 (3.3% students had evidence of new dengue infections during one school term (5 months. There was no significant difference in proportions of students having incident dengue infections between the intervention and control schools, with adjustment for clustering by school. WHOPES cone tests showed a 100% knock down and mortality of Aedes aegypti mosquitoes exposed to impregnated clothing at baseline and up to 4 washes, but this efficacy rapidly declined to below 20% after 20 washes, corresponding to a weekly reduction in knock-down and mosquito mortality by 4.7% and 4.4% respectively. Results of the entomological assessments showed that the mean number of Aedes aegypti mosquitoes caught inside the classrooms of the intervention schools was significantly reduced in the month following the introduction of the impregnated uniforms, compared to those collected in classrooms of the control schools (p = 0.04.Entomological assessments showed that the intervention had some impact on the number of Aedes

  6. Mitigating Diseases Transmitted by Aedes Mosquitoes: A Cluster-Randomised Trial of Permethrin-Impregnated School Uniforms.

    Science.gov (United States)

    Kittayapong, Pattamaporn; Olanratmanee, Phanthip; Maskhao, Pongsri; Byass, Peter; Logan, James; Tozan, Yesim; Louis, Valérie; Gubler, Duane J; Wilder-Smith, Annelies

    2017-01-01

    Viral diseases transmitted via Aedes mosquitoes are on the rise, such as Zika, dengue, and chikungunya. Novel tools to mitigate Aedes mosquitoes-transmitted diseases are urgently needed. We tested whether commercially insecticide-impregnated school uniforms can reduce dengue incidence in school children. We designed a cluster-randomised controlled trial in Thailand. The primary endpoint was laboratory-confirmed dengue infections. Secondary endpoints were school absenteeism; and impregnated uniforms' 1-hour knock-down and 24 hour mosquito mortality as measured by standardised WHOPES bioassay cone tests at baseline and after repeated washing. Furthermore, entomological assessments inside classrooms and in outside areas of schools were conducted. We enrolled 1,811 pupils aged 6-17 from 5 intervention and 5 control schools. Paired serum samples were obtained from 1,655 pupils. In the control schools, 24/641 (3.7%) and in the intervention schools 33/1,014 (3.3%) students had evidence of new dengue infections during one school term (5 months). There was no significant difference in proportions of students having incident dengue infections between the intervention and control schools, with adjustment for clustering by school. WHOPES cone tests showed a 100% knock down and mortality of Aedes aegypti mosquitoes exposed to impregnated clothing at baseline and up to 4 washes, but this efficacy rapidly declined to below 20% after 20 washes, corresponding to a weekly reduction in knock-down and mosquito mortality by 4.7% and 4.4% respectively. Results of the entomological assessments showed that the mean number of Aedes aegypti mosquitoes caught inside the classrooms of the intervention schools was significantly reduced in the month following the introduction of the impregnated uniforms, compared to those collected in classrooms of the control schools (p = 0.04). Entomological assessments showed that the intervention had some impact on the number of Aedes mosquitoes inside

  7. A community mobilisation intervention to prevent violence against women and reduce HIV/AIDS risk in Kampala, Uganda (the SASA! Study): study protocol for a cluster randomised controlled trial

    Science.gov (United States)

    2012-01-01

    Background Gender based violence, including violence by an intimate partner, is a major global human rights and public health problem, with important connections with HIV risk. Indeed, the elimination of sexual and gender based violence is a core pillar of HIV prevention for UNAIDS. Integrated strategies to address the gender norms, relations and inequities that underlie both violence against women and HIV/AIDS are needed. However there is limited evidence about the potential impact of different intervention models. This protocol describes the SASA! Study: an evaluation of a community mobilisation intervention to prevent violence against women and reduce HIV/AIDS risk in Kampala, Uganda. Methods/Design The SASA! Study is a pair-matched cluster randomised controlled trial being conducted in eight communities in Kampala. It is designed to assess the community-level impact of the SASA! intervention on the following six primary outcomes: attitudes towards the acceptability of violence against women and the acceptability of a woman refusing sex (among male and female community members); past year experience of physical intimate partner violence and sexual intimate partner violence (among females); community responses to women experiencing violence (among women reporting past year physical/sexual partner violence); and past year concurrency of sexual partners (among males). 1583 women and men (aged 18–49 years) were surveyed in intervention and control communities prior to intervention implementation in 2007/8. A follow-up cross-sectional survey of community members will take place in 2012. The primary analysis will be an adjusted cluster-level intention to treat analysis, comparing outcomes in intervention and control communities at follow-up. Complementary monitoring and evaluation and qualitative research will be used to explore and describe the process of intervention implementation and the pathways through which change is achieved. Discussion This is one of few

  8. Cluster Randomised Trials in Cochrane Reviews: Evaluation of Methodological and Reporting Practice.

    Directory of Open Access Journals (Sweden)

    Marty Richardson

    Full Text Available Systematic reviews can include cluster-randomised controlled trials (C-RCTs, which require different analysis compared with standard individual-randomised controlled trials. However, it is not known whether review authors follow the methodological and reporting guidance when including these trials. The aim of this study was to assess the methodological and reporting practice of Cochrane reviews that included C-RCTs against criteria developed from existing guidance.Criteria were developed, based on methodological literature and personal experience supervising review production and quality. Criteria were grouped into four themes: identifying, reporting, assessing risk of bias, and analysing C-RCTs. The Cochrane Database of Systematic Reviews was searched (2nd December 2013, and the 50 most recent reviews that included C-RCTs were retrieved. Each review was then assessed using the criteria.The 50 reviews we identified were published by 26 Cochrane Review Groups between June 2013 and November 2013. For identifying C-RCTs, only 56% identified that C-RCTs were eligible for inclusion in the review in the eligibility criteria. For reporting C-RCTs, only eight (24% of the 33 reviews reported the method of cluster adjustment for their included C-RCTs. For assessing risk of bias, only one review assessed all five C-RCT-specific risk-of-bias criteria. For analysing C-RCTs, of the 27 reviews that presented unadjusted data, only nine (33% provided a warning that confidence intervals may be artificially narrow. Of the 34 reviews that reported data from unadjusted C-RCTs, only 13 (38% excluded the unadjusted results from the meta-analyses.The methodological and reporting practices in Cochrane reviews incorporating C-RCTs could be greatly improved, particularly with regard to analyses. Criteria developed as part of the current study could be used by review authors or editors to identify errors and improve the quality of published systematic reviews incorporating

  9. Special features of health services and register based trials – experiences from a randomized trial of childbirth classes

    Directory of Open Access Journals (Sweden)

    Sevón Tiina

    2008-06-01

    Full Text Available Abstract Background Evaluating complex interventions in health services faces various difficulties, such as making practice changes and costs. Ways to increase research capacity and decrease costs include making research an integral part of health services and using routine data to judge outcomes. The purpose of this article is to report the feasibility of a pilot trial relying solely on routinely collected register data and being based on ordinary health services. Methods The example intervention was education to public health nurses (PHN (childbirth classes to reduce caesarean section rates via pre-delivery considerations of pregnant women. 20 maternity health centers (MHC were paired and of each 10 pairs, one MHC was randomly allocated to an intervention group and the other to a control; 8 pairs with successful intervention were used in the analyses (1601 mothers. The women visiting to the study maternity centers were identified from the Customer Register of Helsinki City. A list of the study women was made using the mother's personal identification number, visit date, the maternity center code, birth date and gestation length. The mode of delivery and health outcomes were retrieved from the Finnish Medical Birth Register (MBR. Process data of the intervention are based on observations, written feedback and questionnaires from PHNs, and project correspondence. Results It took almost two years to establish how to obtain permissions and to actually obtain it for the trial. Obtaining permissions for the customer and outcome data and register linkages was unproblematic and the cluster randomization provided comparable groups. The intervention did not succeed well. Had the main aim of the trial been to cause a change in PHNs behavior, we would have very likely intensified the intervention during the trial. Conclusion Our experiences encourage the use of trials that obtain their outcomes from registers. Changing the behavior of ordinary health

  10. Cluster randomized trial in the general practice research database: 2. Secondary prevention after first stroke (eCRT study: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Dregan Alex

    2012-10-01

    Full Text Available Abstract Background The purpose of this research is to develop and evaluate methods for conducting pragmatic cluster randomized trials in a primary care electronic database. The proposal describes one application, in a less frequent chronic condition of public health importance, secondary prevention of stroke. A related protocol in antibiotic prescribing was reported previously. Methods/Design The study aims to implement a cluster randomized trial (CRT using the electronic patient records of the General Practice Research Database (GPRD as a sampling frame and data source. The specific objective of the trial is to evaluate the effectiveness of a computer-delivered intervention at enhancing the delivery of stroke secondary prevention in primary care. GPRD family practices will be allocated to the intervention or usual care. The intervention promotes the use of electronic prompts to support adherence with the recommendations of the UK Intercollegiate Stroke Working Party and NICE guidelines for the secondary prevention of stroke in primary care. Primary outcome measure will be the difference in systolic blood pressure between intervention and control trial arms at 12-month follow-up. Secondary outcomes will be differences in serum cholesterol, prescribing of antihypertensive drugs, statins, and antiplatelet therapy. The intervention will continue for 12 months. Information on the utilization of the decision-support tools will also be analyzed. Discussion The CRT will investigate the effectiveness of using a computer-delivered intervention to reduce the risk of stroke recurrence following a first stroke event. The study will provide methodological guidance on the implementation of CRTs in electronic databases in primary care. Trial registration Current Controlled Trials ISRCTN35701810

  11. Traveling cluster approximation for uncorrelated amorphous systems

    International Nuclear Information System (INIS)

    Kaplan, T.; Sen, A.K.; Gray, L.J.; Mills, R.

    1985-01-01

    In this paper, the authors apply the TCA concepts to spatially disordered, uncorrelated systems (e.g., fluids or amorphous metals without short-range order). This is the first approximation scheme for amorphous systems that takes cluster effects into account while preserving the Herglotz property for any amount of disorder. They have performed some computer calculations for the pair TCA, for the model case of delta-function potentials on a one-dimensional random chain. These results are compared with exact calculations (which, in principle, taken into account all cluster effects) and with the CPA, which is the single-site TCA. The density of states for the pair TCA clearly shows some improvement over the CPA, and yet, apparently, the pair approximation distorts some of the features of the exact results. They conclude that the effects of large clusters are much more important in an uncorrelated liquid metal than in a substitutional alloy. As a result, the pair TCA, which does quite a nice job for alloys, is not adequate for the liquid. Larger clusters must be treated exactly, and therefore an n-TCA with n > 2 must be used

  12. DISCOVERY OF A PAIR OF CLASSICAL CEPHEIDS IN AN INVISIBLE CLUSTER BEYOND THE GALACTIC BULGE

    Energy Technology Data Exchange (ETDEWEB)

    Dékány, I.; Palma, T. [Millennium Institute of Astrophysics, Santiago (Chile); Minniti, D. [Departamento de Ciencias Físicas, Universidad Andres Bello, República 220, Santiago (Chile); Hajdu, G.; Alonso-García, J.; Hempel, M.; Catelan, M. [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago (Chile); Gieren, W. [Departamento de Astronomía, Universidad de Concepción, Casilla 160 C, Concepción (Chile); Majaess, D. [Department of Astronomy and Physics, Saint Mary’s University, Halifax, NS B3H 3C3 (Canada)

    2015-01-20

    We report the discovery of a pair of extremely reddened classical Cepheid variable stars located in the Galactic plane behind the bulge, using near-infrared (NIR) time-series photometry from the VISTA Variables in the Vía Láctea Survey. This is the first time that such objects have ever been found in the opposite side of the Galactic plane. The Cepheids have almost identical periods, apparent brightnesses, and colors. From the NIR Leavitt law, we determine their distances with ∼1.5% precision and ∼8% accuracy. We find that they have a same total extinction of A(V)≃32 mag, and are located at the same heliocentric distance of 〈d〉=11.4±0.9 kpc, and less than 1 pc from the true Galactic plane. Their similar periods indicate that the Cepheids are also coeval, with an age of ∼48±3 Myr, according to theoretical models. They are separated by an angular distance of only 18.″3, corresponding to a projected separation of ∼1 pc. Their position coincides with the expected location of the Far 3 kpc Arm behind the bulge. Such a tight pair of similar classical Cepheids indicates the presence of an underlying young open cluster that is both hidden behind heavy extinction and disguised by the dense stellar field of the bulge. All our attempts to directly detect this “invisible cluster” have failed, and deeper observations are needed. (letters)

  13. Study of Pair and many-body interactions in rare-gas halide atom clusters using negative ion zero electron kinetic energy (ZEKE) and threshold photodetachment spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yourshaw, Ivan [Univ. of California, Berkeley, CA (United States)

    1998-07-09

    The diatomic halogen atom-rare gas diatomic complexes KrBr-, XeBr-, and KrCl- are studied in this work by zero electron kinetic energy (ZEKE) spectroscopy in order to characterize the weak intermolecular diatomic potentials of these species. Also, the ZEKE and threshold photodetachment spectra of the polyatomic clusters ArnBr- (n = 2-9) and ArnI- (n = 2-19) are studied to obtain information about the non-additive effects on the interactions among the atoms. This work is part of an ongoing effort to characterize the pair and many-body potentials of the complete series of rare gas halide clusters. In these studies we obtain information about both the anionic and neutral clusters.

  14. Analyzing indirect effects in cluster randomized trials. The effect of estimation method, number of groups and group sizes on accuracy and power.

    Directory of Open Access Journals (Sweden)

    Joop eHox

    2014-02-01

    Full Text Available Cluster randomized trials assess the effect of an intervention that is carried out at the group or cluster level. Ajzen’s theory of planned behaviour is often used to model the effect of the intervention as an indirect effect mediated in turn by attitude, norms and behavioural intention. Structural equation modelling (SEM is the technique of choice to estimate indirect effects and their significance. However, this is a large sample technique, and its application in a cluster randomized trial assumes a relatively large number of clusters. In practice, the number of clusters in these studies tends to be relatively small, e.g. much less than fifty. This study uses simulation methods to find the lowest number of clusters needed when multilevel SEM is used to estimate the indirect effect. Maximum likelihood estimation is compared to Bayesian analysis, with the central quality criteria being accuracy of the point estimate and the confidence interval. We also investigate the power of the test for the indirect effect. We conclude that Bayes estimation works well with much smaller cluster level sample sizes such as 20 cases than maximum likelihood estimation; although the bias is larger the coverage is much better. When only 5 to 10 clusters are available per treatment condition even with Bayesian estimation problems occur.

  15. Universal Prevention for Anxiety and Depressive Symptoms in Children: A Meta-analysis of Randomized and Cluster-Randomized Trials.

    Science.gov (United States)

    Ahlen, Johan; Lenhard, Fabian; Ghaderi, Ata

    2015-12-01

    Although under-diagnosed, anxiety and depression are among the most prevalent psychiatric disorders in children and adolescents, leading to severe impairment, increased risk of future psychiatric problems, and a high economic burden to society. Universal prevention may be a potent way to address these widespread problems. There are several benefits to universal relative to targeted interventions because there is limited knowledge as to how to screen for anxiety and depression in the general population. Earlier meta-analyses of the prevention of depression and anxiety symptoms among children suffer from methodological inadequacies such as combining universal, selective, and indicated interventions in the same analyses, and comparing cluster-randomized trials with randomized trials without any correction for clustering effects. The present meta-analysis attempted to determine the effectiveness of universal interventions to prevent anxiety and depressive symptoms after correcting for clustering effects. A systematic search of randomized studies in PsychINFO, Cochrane Library, and Google Scholar resulted in 30 eligible studies meeting inclusion criteria, namely peer-reviewed, randomized or cluster-randomized trials of universal interventions for anxiety and depressive symptoms in school-aged children. Sixty-three percent of the studies reported outcome data regarding anxiety and 87 % reported outcome data regarding depression. Seventy percent of the studies used randomization at the cluster level. There were small but significant effects regarding anxiety (.13) and depressive (.11) symptoms as measured at immediate posttest. At follow-up, which ranged from 3 to 48 months, effects were significantly larger than zero regarding depressive (.07) but not anxiety (.11) symptoms. There was no significant moderation effect of the following pre-selected variables: the primary aim of the intervention (anxiety or depression), deliverer of the intervention, gender distribution

  16. Effectiveness of the 'Healthy School and Drugs' prevention programme on adolescents' substance use: a randomized clustered trial

    NARCIS (Netherlands)

    Malmberg, M.; Kleinjan, M.; Overbeek, G.; Vermulst, A.; Monshouwer, K.; Lammers, J.; Vollebergh, W.A.M.; Engels, R.C.M.E.

    2014-01-01

    Aim: To evaluate the effectiveness of the Healthy School and Drugs programme on alcohol, tobacco and marijuana use among Dutch early adolescents. Design: Randomized clustered trial with two intervention conditions (i.e. e-learning and integral). Setting: General population of 11-15-year-old

  17. Effectiveness of the 'Healthy School and Drugs' prevention programme on adolescents' substance use : A randomized clustered trial

    NARCIS (Netherlands)

    Malmberg, Monique; Kleinjan, Marloes; Overbeek, Geertjan; Vermulst, Ad; Monshouwer, Karin; Lammers, Jeroen; Vollebergh, Wilma A M; Engels, Rutger C M E

    2014-01-01

    Aim: To evaluate the effectiveness of the Healthy School and Drugs programme on alcohol, tobacco and marijuana use among Dutch early adolescents. Design: Randomized clustered trial with two intervention conditions (i.e. e-learning and integral). Setting: General population of 11-15-year-old

  18. Effectiveness of the 'Healthy School and Drugs' prevention programme on adolescents' substance use: a randomized clustered trial

    NARCIS (Netherlands)

    Malmberg, M.; Kleinjan, M.; Overbeek, G.J.; Vermulst, A.A.; Monshouwer, K.; Lammers, J.; Vollebergh, W.A.M.; Engels, R.C.M.E.

    2014-01-01

    Aim To evaluate the effectiveness of the Healthy School and Drugs programme on alcohol, tobacco and marijuana use among Dutch early adolescents. Design Randomized clustered trial with two intervention conditions (i.e. e-learning and integral). Setting General population of 11-15-year-old adolescents

  19. Can cannabis use be prevented by targeting personality risk in schools? Twenty?four?month outcome of the adventure trial on cannabis use: a cluster?randomized controlled trial

    OpenAIRE

    Mahu, Ioan T.; Doucet, Christine; O'Leary?Barrett, Maeve; Conrod, Patricia J.

    2015-01-01

    Aims To examine the effectiveness of a personality?targeted intervention program (Adventure trial) delivered by trained teachers to high?risk (HR) high?school students on reducing marijuana use and frequency of use. Design A cluster?randomized controlled trial. Setting Secondary schools in London, UK. Participants Twenty?one secondary schools were randomized to intervention (n?=?12) or control (n?=?9) conditions, encompassing a total of 1038 HR students in the ninth grade [mean (standard devi...

  20. Information and Choice of A-Level Subjects: A Cluster Randomised Controlled Trial with Linked Administrative Data

    Science.gov (United States)

    Davies, Peter; Davies, Neil M.; Qiu, Tian

    2017-01-01

    We estimated the effects of an intervention which provided information about graduate wages to 5593 students in England, using a blinded cluster randomised controlled trial in 50 schools (registration: AEARCTR-0000468). Our primary outcome was students' choice of A-level subjects at age 16. We also recorded the students' expectations of future…

  1. The optimal design of stepped wedge trials with equal allocation to sequences and a comparison to other trial designs.

    Science.gov (United States)

    Thompson, Jennifer A; Fielding, Katherine; Hargreaves, James; Copas, Andrew

    2017-12-01

    Background/Aims We sought to optimise the design of stepped wedge trials with an equal allocation of clusters to sequences and explored sample size comparisons with alternative trial designs. Methods We developed a new expression for the design effect for a stepped wedge trial, assuming that observations are equally correlated within clusters and an equal number of observations in each period between sequences switching to the intervention. We minimised the design effect with respect to (1) the fraction of observations before the first and after the final sequence switches (the periods with all clusters in the control or intervention condition, respectively) and (2) the number of sequences. We compared the design effect of this optimised stepped wedge trial to the design effects of a parallel cluster-randomised trial, a cluster-randomised trial with baseline observations, and a hybrid trial design (a mixture of cluster-randomised trial and stepped wedge trial) with the same total cluster size for all designs. Results We found that a stepped wedge trial with an equal allocation to sequences is optimised by obtaining all observations after the first sequence switches and before the final sequence switches to the intervention; this means that the first sequence remains in the control condition and the last sequence remains in the intervention condition for the duration of the trial. With this design, the optimal number of sequences is [Formula: see text], where [Formula: see text] is the cluster-mean correlation, [Formula: see text] is the intracluster correlation coefficient, and m is the total cluster size. The optimal number of sequences is small when the intracluster correlation coefficient and cluster size are small and large when the intracluster correlation coefficient or cluster size is large. A cluster-randomised trial remains more efficient than the optimised stepped wedge trial when the intracluster correlation coefficient or cluster size is small. A

  2. Effectiveness of a multifaceted implementation strategy on physicians' referral behavior to an evidence-based psychosocial intervention in dementia: a cluster randomized controlled trial

    NARCIS (Netherlands)

    Dopp, C.M.E.; Graff, M.J.L.; Teerenstra, S.; Nijhuis-Van der Sanden, M.W.; Olde Rikkert, M.G.M.; Vernooij-Dassen, M.J.F.J.

    2013-01-01

    BACKGROUND: To evaluate the effectiveness of a multifaceted implementation strategy on physicians' referral rate to and knowledge on the community occupational therapy in dementia program (COTiD program). METHODS: A cluster randomized controlled trial with 28 experimental and 17 control clusters was

  3. Evaluating a multicomponent social behaviour change communication strategy to reduce intimate partner violence among married couples: study protocol for a cluster randomized trial in Nepal

    Directory of Open Access Journals (Sweden)

    Cari Jo Clark

    2017-01-01

    Full Text Available Abstract Background Intimate partner violence (IPV is a significant public health issue that affects 1 in 3 women globally and a similarly large number of women in Nepal. Over the past decade, important policy and programmatic steps have been taken to address violence against women in Nepal. There remains a dearth of evidence on the effectiveness of primary violence prevention strategies. The Change Starts at Home study begins to fill this gap by utilizing a multi-component social behaviour change communication (SBCC strategy involving a radio drama and community mobilization to shift attitudes, norms and behaviours that underpin IPV perpetration in Nepal. Methods/Design The study uses a concurrent mixed-methods design. The quantitative aspect of the evaluation is a pair-matched, repeated cross-sectional 2-armed, single-blinded cluster trial (RCT: N = 36 clusters, 1440 individuals, comparing a social behaviour change communication (SBCC strategy to radio programming alone for its impact on physical and / or sexual IPV at the end of programming (12 months’ post-baseline and 6-months post the cessation of project activities (18-months post baseline. The qualitative aspects of the design include several longitudinal approaches to understand the impact of the intervention and to examine mechanisms of change including in-depth interviews with participants (N = 18 couples, and focus group discussions with community leaders (N = 3 groups, and family members of participants (N = 12 groups. Treatment effects will be estimated with generalized logistic mixed models specified to compare differences in primary outcome from baseline to 12-month follow-up, and baseline to 18-months follow-up in accordance with intention-to-treat principles. Discussion The study rigorously evaluates the effectiveness of a promising strategy to prevent IPV. The results of the trial will be immediately useful for governmental, nongovernmental, and donor funded

  4. Task shifting of frontline community health workers for cardiovascular risk reduction: design and rationale of a cluster randomised controlled trial (DISHA study) in India.

    Science.gov (United States)

    Jeemon, Panniyammakal; Narayanan, Gitanjali; Kondal, Dimple; Kahol, Kashvi; Bharadwaj, Ashok; Purty, Anil; Negi, Prakash; Ladhani, Sulaiman; Sanghvi, Jyoti; Singh, Kuldeep; Kapoor, Deksha; Sobti, Nidhi; Lall, Dorothy; Manimunda, Sathyaprakash; Dwivedi, Supriya; Toteja, Gurudyal; Prabhakaran, Dorairaj

    2016-03-15

    Effective task-shifting interventions targeted at reducing the global cardiovascular disease (CVD) epidemic in low and middle-income countries (LMICs) are urgently needed. DISHA is a cluster randomised controlled trial conducted across 10 sites (5 in phase 1 and 5 in phase 2) in India in 120 clusters. At each site, 12 clusters were randomly selected from a district. A cluster is defined as a small village with 250-300 households and well defined geographical boundaries. They were then randomly allocated to intervention and control clusters in a 1:1 allocation sequence. If any of the intervention and control clusters were workers (mainly Anganwadi workers and ASHA workers) and a post intervention survey in a representative sample. The study staff had no information on intervention allocation until the completion of the baseline survey. In order to ensure comparability of data across sites, the DISHA study follows a common protocol and manual of operation with standardized measurement techniques. Our study is the largest community based cluster randomised trial in low and middle-income country settings designed to test the effectiveness of 'task shifting' interventions involving frontline health workers for cardiovascular risk reduction. CTRI/2013/10/004049 . Registered 7 October 2013.

  5. Participatory women's groups and counselling through home visits to improve child growth in rural eastern India: protocol for a cluster randomised controlled trial.

    Science.gov (United States)

    Nair, Nirmala; Tripathy, Prasanta; Sachdev, Harshpal S; Bhattacharyya, Sanghita; Gope, Rajkumar; Gagrai, Sumitra; Rath, Shibanand; Rath, Suchitra; Sinha, Rajesh; Roy, Swati Sarbani; Shewale, Suhas; Singh, Vijay; Srivastava, Aradhana; Pradhan, Hemanta; Costello, Anthony; Copas, Andrew; Skordis-Worrall, Jolene; Haghparast-Bidgoli, Hassan; Saville, Naomi; Prost, Audrey

    2015-04-15

    Child stunting (low height-for-age) is a marker of chronic undernutrition and predicts children's subsequent physical and cognitive development. Around one third of the world's stunted children live in India. Our study aims to assess the impact, cost-effectiveness, and scalability of a community intervention with a government-proposed community-based worker to improve growth in children under two in rural India. The study is a cluster randomised controlled trial in two rural districts of Jharkhand and Odisha (eastern India). The intervention tested involves a community-based worker carrying out two activities: (a) one home visit to all pregnant women in the third trimester, followed by subsequent monthly home visits to all infants aged 0-24 months to support appropriate feeding, infection control, and care-giving; (b) a monthly women's group meeting using participatory learning and action to catalyse individual and community action for maternal and child health and nutrition. Both intervention and control clusters also receive an intervention to strengthen Village Health Sanitation and Nutrition Committees. The unit of randomisation is a purposively selected cluster of approximately 1000 population. A total of 120 geographical clusters covering an estimated population of 121,531 were randomised to two trial arms: 60 clusters in the intervention arm receive home visits, group meetings, and support to Village Health Sanitation and Nutrition Committees; 60 clusters in the control arm receive support to Committees only. The study participants are pregnant women identified in the third trimester of pregnancy and their children (n = 2520). Mothers and their children are followed up at seven time points: during pregnancy, within 72 hours of delivery, and at 3, 6, 9, 12 and 18 months after birth. The trial's primary outcome is children's mean length-for-age Z scores at 18 months. Secondary outcomes include wasting and underweight at all time points, birth weight, growth

  6. Complexes of DNA bases and Watson-Crick base pairs interaction with neutral silver Agn (n = 8, 10, 12) clusters: a DFT and TDDFT study.

    Science.gov (United States)

    Srivastava, Ruby

    2018-03-01

    We study the binding of the neutral Ag n (n = 8, 10, 12) to the DNA base-adenine (A), guanine (G) and Watson-Crick -adenine-thymine, guanine-cytosine pairs. Geometries of complexes were optimized at the DFT level using the hybrid B3LYP functional. LANL2DZ effective core potential was used for silver and 6-31 + G ** was used for all other atoms. NBO charges were analyzed using the Natural population analysis. The absorption properties of Ag n -A,G/WC complexes were also studied using time-dependent density functional theory. The absorption spectra for these complexes show wavelength in the visible region. It was revealed that silver clusters interact more strongly with WC pairs than with isolated DNA complexes. Furthermore, it was found that the electronic charge transferred from silver to isolated DNA clusters are less than the electronic charge transferred from silver to the Ag n -WC complexes. The vertical ionization potential, vertical electron affinity, hardness, and electrophilicity index of Ag n -DNA/WC complexes have also been discussed.

  7. A community mobilisation intervention to prevent violence against women and reduce HIV/AIDS risk in Kampala, Uganda (the SASA! Study: study protocol for a cluster randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Abramsky Tanya

    2012-06-01

    Full Text Available Abstract Background Gender based violence, including violence by an intimate partner, is a major global human rights and public health problem, with important connections with HIV risk. Indeed, the elimination of sexual and gender based violence is a core pillar of HIV prevention for UNAIDS. Integrated strategies to address the gender norms, relations and inequities that underlie both violence against women and HIV/AIDS are needed. However there is limited evidence about the potential impact of different intervention models. This protocol describes the SASA! Study: an evaluation of a community mobilisation intervention to prevent violence against women and reduce HIV/AIDS risk in Kampala, Uganda. Methods/Design The SASA! Study is a pair-matched cluster randomised controlled trial being conducted in eight communities in Kampala. It is designed to assess the community-level impact of the SASA! intervention on the following six primary outcomes: attitudes towards the acceptability of violence against women and the acceptability of a woman refusing sex (among male and female community members; past year experience of physical intimate partner violence and sexual intimate partner violence (among females; community responses to women experiencing violence (among women reporting past year physical/sexual partner violence; and past year concurrency of sexual partners (among males. 1583 women and men (aged 18–49 years were surveyed in intervention and control communities prior to intervention implementation in 2007/8. A follow-up cross-sectional survey of community members will take place in 2012. The primary analysis will be an adjusted cluster-level intention to treat analysis, comparing outcomes in intervention and control communities at follow-up. Complementary monitoring and evaluation and qualitative research will be used to explore and describe the process of intervention implementation and the pathways through which change is achieved

  8. Using Cluster Bootstrapping to Analyze Nested Data with a Few Clusters

    Science.gov (United States)

    Huang, Francis L.

    2018-01-01

    Cluster randomized trials involving participants nested within intact treatment and control groups are commonly performed in various educational, psychological, and biomedical studies. However, recruiting and retaining intact groups present various practical, financial, and logistical challenges to evaluators and often, cluster randomized trials…

  9. Determining the impact of a new physiotherapist-led primary care model for back pain: protocol for a pilot cluster randomized controlled trial.

    Science.gov (United States)

    Miller, Jordan; Barber, David; Donnelly, Catherine; French, Simon; Green, Michael; Hill, Jonathan; MacDermid, Joy; Marsh, Jacquelyn; Norman, Kathleen; Richardson, Julie; Taljaard, Monica; Wideman, Timothy; Cooper, Lynn; McPhee, Colleen

    2017-11-09

    Back pain is a leading contributor to disability, healthcare costs, and lost work. Family physicians are the most common first point of contact in the healthcare system for people with back pain, but physiotherapists (PTs) may be able to support the primary care team through evidence-based primary care. A cluster randomized trial is needed to determine the clinical, health system, and societal impact of a primary care model that integrates physiotherapists at the first visit for people with back pain. Prior to conducting a future fully powered cluster randomized trial, we need to demonstrate feasibility of the methods. Therefore, the purpose of this pilot study will be to: 1) Determine feasibility of patient recruitment, assessment procedures, and retention. 2) Determine the feasibility of training and implementation of a new PT-led primary care model for low back pain (LBP) 3) Explore the perspectives of patients and healthcare providers (HCPs) related to their experiences and attitudes towards the new service delivery model, barriers/facilitators to implementation, perceived satisfaction, perceived value, and impact on clinic processes and patient outcomes. This pilot cluster randomized controlled trial will enroll four sites and randomize them to implement a new PT-led primary care model for back pain or a usual physician-led primary care model. All adults booking a primary care visit for back pain will be invited to participate. Feasibility outcomes will include: recruitment and retention rates, completeness of assessment data, PT training participation and confidence after training, and PT treatment fidelity. Secondary outcomes will include the clinical, health system, cost, and process outcomes planned for the future fully powered cluster trial. Results will be analyzed and reported descriptively and qualitatively. To explore perspectives of both HCPs and patients, we will conduct semi-structured qualitative interviews with patients and focus groups with HCPs

  10. Seniority-based coupled cluster theory

    International Nuclear Information System (INIS)

    Henderson, Thomas M.; Scuseria, Gustavo E.; Bulik, Ireneusz W.; Stein, Tamar

    2014-01-01

    Doubly occupied configuration interaction (DOCI) with optimized orbitals often accurately describes strong correlations while working in a Hilbert space much smaller than that needed for full configuration interaction. However, the scaling of such calculations remains combinatorial with system size. Pair coupled cluster doubles (pCCD) is very successful in reproducing DOCI energetically, but can do so with low polynomial scaling (N 3 , disregarding the two-electron integral transformation from atomic to molecular orbitals). We show here several examples illustrating the success of pCCD in reproducing both the DOCI energy and wave function and show how this success frequently comes about. What DOCI and pCCD lack are an effective treatment of dynamic correlations, which we here add by including higher-seniority cluster amplitudes which are excluded from pCCD. This frozen pair coupled cluster approach is comparable in cost to traditional closed-shell coupled cluster methods with results that are competitive for weakly correlated systems and often superior for the description of strongly correlated systems

  11. A community-based cluster randomized controlled trial (cRCT) to evaluate the impact and operational assessment of "safe motherhood and newborn health promotion package": study protocol.

    Science.gov (United States)

    Hoque, Dewan Md Emdadul; Chowdhury, Mohiuddin Ahsanul Kabir; Rahman, Ahmed Ehsanur; Billah, Sk Masum; Bari, Sanwarul; Tahsina, Tazeen; Hasan, Mohammad Mehedi; Islam, Sajia; Islam, Tajul; Mori, Rintaro; Arifeen, Shams El

    2018-05-03

    Despite considerable progress in reduction of both under-five and maternal mortality in recent decades, Bangladesh is still one of the low and middle income countries with high burden of maternal and neonatal mortality. The primary objective of the current study is to measure the impact of a comprehensive package of interventions on maternal and neonatal mortality. In addition, changes in coverage, quality and utilization of maternal and newborn health (MNH) services, social capital, and cost effectiveness of the interventions will be measured. A community-based, cluster randomized controlled trial design will be adopted and implemented in 30 unions of three sub-districts of Chandpur district of Bangladesh. Every union, the lowest administrative unit of the local government with population of around 20,000-30,000, will be considered a cluster. Based on the baseline estimates, 15 clusters will be paired for random assignment as intervention and comparison clusters. The primary outcome measure is neonatal mortality, and secondary outcomes are coverage of key interventions like ANC, PNC, facility and skilled provider delivery. Baseline, midterm and endline household survey will be conducted to assess the key coverage of interventions. Health facility assessment surveys will be conducted periodically to assess facility readiness and utilization of MNH services in the participating health facilities. The current study is expected to provide essential strong evidences on the impact of a comprehensive package of interventions to the Bangladesh government, and other developmental partners. The study results may help in prioritizing, planning, and scaling-up of Safe Motherhood Promotional interventions in other geographical areas of Bangladesh as well as to inform other developing countries of similar settings. NCT03032276 .

  12. A combined community- and facility-based approach to improve pregnancy outcomes in low-resource settings: a Global Network cluster randomized trial.

    Science.gov (United States)

    Pasha, Omrana; McClure, Elizabeth M; Wright, Linda L; Saleem, Sarah; Goudar, Shivaprasad S; Chomba, Elwyn; Patel, Archana; Esamai, Fabian; Garces, Ana; Althabe, Fernando; Kodkany, Bhala; Mabeya, Hillary; Manasyan, Albert; Carlo, Waldemar A; Derman, Richard J; Hibberd, Patricia L; Liechty, Edward K; Krebs, Nancy; Hambidge, K Michael; Buekens, Pierre; Moore, Janet; Jobe, Alan H; Koso-Thomas, Marion; Wallace, Dennis D; Stalls, Suzanne; Goldenberg, Robert L

    2013-10-03

    Fetal and neonatal mortality rates in low-income countries are at least 10-fold greater than in high-income countries. These differences have been related to poor access to and poor quality of obstetric and neonatal care. This trial tested the hypothesis that teams of health care providers, administrators and local residents can address the problem of limited access to quality obstetric and neonatal care and lead to a reduction in perinatal mortality in intervention compared to control locations. In seven geographic areas in five low-income and one middle-income country, most with high perinatal mortality rates and substantial numbers of home deliveries, we performed a cluster randomized non-masked trial of a package of interventions that included community mobilization focusing on birth planning and hospital transport, community birth attendant training in problem recognition, and facility staff training in the management of obstetric and neonatal emergencies. The primary outcome was perinatal mortality at ≥28 weeks gestation or birth weight ≥1000 g. Despite extensive effort in all sites in each of the three intervention areas, no differences emerged in the primary or any secondary outcome between the intervention and control clusters. In both groups, the mean perinatal mortality was 40.1/1,000 births (P = 0.9996). Neither were there differences between the two groups in outcomes in the last six months of the project, in the year following intervention cessation, nor in the clusters that best implemented the intervention. This cluster randomized comprehensive, large-scale, multi-sector intervention did not result in detectable impact on the proposed outcomes. While this does not negate the importance of these interventions, we expect that achieving improvement in pregnancy outcomes in these settings will require substantially more obstetric and neonatal care infrastructure than was available at the sites during this trial, and without them provider training

  13. SPACE for physical activity - a multicomponent intervention study: study design and baseline findings from a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Kristensen Peter L

    2011-10-01

    Full Text Available Abstract Background The aim of the School site, Play Spot, Active transport, Club fitness and Environment (SPACE Study was to develop, document, and assess a comprehensive intervention in local school districts that promote everyday physical activity (PA among 11-15-year-old adolescents. The study is based on a social ecological framework, and is designed to implement organizational and structural changes in the physical environment. Methods/design The SPACE Study used a cluster randomized controlled study design. Twenty-one eligible schools in the Region of Southern Denmark were matched and randomized in seven pairs according to eight matching variables summarized in an audit tool (crow-fly distance from residence to school for 5-6th graders; area household income; area education level; area ethnicity distribution; school district urbanity; condition and characteristics of school outdoor areas; school health policy; and active transport in the local area. Baseline measurements with accelerometers, questionnaires, diaries, and physical fitness tests were obtained in Spring 2010 in 5-6th grade in 7 intervention and 7 control schools, with follow-up measurements to be taken in Spring 2012 in 7-8th grade. The primary outcome measure is objective average daily physical activity and will be supported by analyses of time spent in moderate to vigorous activity and time spent sedentary. Other secondary outcome measures will be obtained, such as, overweight, physical fitness, active commuting to/from school and physical activity in recess periods. Discussion A total of 1348 adolescents in 5-6th grade in the Region of Southern Denmark participated at baseline (n = 14 schools. The response rate was high in all type of measurements (72.6-97.4%. There were no significant differences between intervention and control groups at baseline according to selected background variables and outcome measures: gender (p = .54, age (p = .17, BMI (p = .59, waist

  14. A cluster randomized controlled trial testing the effectiveness of Houvast: A strengths-based intervention for homeless young adults

    NARCIS (Netherlands)

    Krabbenborg, M.A.M.; Boersma, S.N.; Veld, W.M. van der; Hulst, B. van; Vollebergh, W.A.M.; Wolf, J.R.L.M.

    2017-01-01

    Objective: To test the effectiveness of Houvast: a strengths-based intervention for homeless young adults. Method: A cluster randomized controlled trial was conducted with 10 Dutch shelter facilities randomly allocated to an intervention and a control group. Homeless young adults were interviewed

  15. Engineering practice variation through provider agreement: a cluster-randomized feasibility trial.

    Science.gov (United States)

    McCarren, Madeline; Twedt, Elaine L; Mansuri, Faizmohamed M; Nelson, Philip R; Peek, Brian T

    2014-01-01

    Minimal-risk randomized trials that can be embedded in practice could facilitate learning health-care systems. A cluster-randomized design was proposed to compare treatment strategies by assigning clusters (eg, providers) to "favor" a particular drug, with providers retaining autonomy for specific patients. Patient informed consent might be waived, broadening inclusion. However, it is not known if providers will adhere to the assignment or whether institutional review boards will waive consent. We evaluated the feasibility of this trial design. Agreeable providers were randomized to "favor" either hydrochlorothiazide or chlorthalidone when starting patients on thiazide-type therapy for hypertension. The assignment applied when the provider had already decided to start a thiazide, and providers could deviate from the strategy as needed. Prescriptions were aggregated to produce a provider strategy-adherence rate. All four institutional review boards waived documentation of patient consent. Providers (n=18) followed their assigned strategy for most of their new thiazide prescriptions (n=138 patients). In the "favor hydrochlorothiazide" group, there was 99% adherence to that strategy. In the "favor chlorthalidone" group, chlorthalidone comprised 77% of new thiazide starts, up from 1% in the pre-study period. When the assigned strategy was followed, dosing in the recommended range was 48% for hydrochlorothiazide (25-50 mg/day) and 100% for chlorthalidone (12.5-25.0 mg/day). Providers were motivated to participate by a desire to contribute to a comparative effectiveness study. A study promotional mug, provider information letter, and interactions with the site investigator were identified as most helpful in reminding providers of their study drug strategy. Providers prescribed according to an assigned drug-choice strategy most of the time for the purpose of a comparative effectiveness study. This simple design could facilitate research participation and behavior change

  16. Trial baseline characteristics of a cluster randomised controlled trial of a school-located obesity prevention programme; the Healthy Lifestyles Programme (HeLP trial

    Directory of Open Access Journals (Sweden)

    Jenny Lloyd

    2017-04-01

    Full Text Available Abstract Background We have developed a healthy lifestyles programme (HeLP for primary school aged children (9–10 years, currently being evaluated in a definitive cluster randomised controlled trial. This paper descriptively presents the baseline characteristics of trial children (BMI, waist circumference, % body fat, diet and physical activity by gender, cluster level socio-economic status, school size and time of recruitment into the trial. Methods Schools were recruited from across the South West of England and allocated 1:1 to either intervention (HeLP or control (usual practice stratified by the proportion of children eligible for free school meals (FSM, 1 Year 5 class. The primary outcome is change in body mass index standard deviation score (BMI sds at 24 months post-randomisation. Secondary outcomes are BMI sds at 18 months, waist circumference and percentage body fat sds at 18 and 24 months, proportion of children classified as underweight, overweight and obese at 18 and 24 months, physical activity (for a sub-sample and food intake at 18 months. Results At baseline 11.4% and 13.6% of children were categorised as overweight or obese respectively. A higher percentage of girls than boys (25.3% vs 24.8% and children from schools in FSM category 2 (28.2% vs 23.2% were overweight or obese. Children were consuming a mean (range of 4.15 (0–13 energy dense snacks (EDS and 3.23 (0–9 healthy snacks (HS per day with children from schools in FSM category 2 consuming more EDS and negative food markers and less HS and positive food markers. Children spent an average 53.6 min per day (11.9 to 124.8 in MVPA and thirteen hours (779.3 min per day (11 h to 15 h doing less than ‘light’ intensity activity. Less than 5% of children achieved the Departments of Health’s recommendation of 60 min of MVPA every day. Conclusion We have excellent completeness of baseline data for all measures and have achieved compliance to accelerometry not

  17. A community mobilisation intervention to prevent violence against women and reduce HIV/AIDS risk in Kampala, Uganda (the SASA! Study): study protocol for a cluster randomised controlled trial.

    Science.gov (United States)

    Abramsky, Tanya; Devries, Karen; Kiss, Ligia; Francisco, Leilani; Nakuti, Janet; Musuya, Tina; Kyegombe, Nambusi; Starmann, Elizabeth; Kaye, Dan; Michau, Lori; Watts, Charlotte

    2012-06-29

    Gender based violence, including violence by an intimate partner, is a major global human rights and public health problem, with important connections with HIV risk. Indeed, the elimination of sexual and gender based violence is a core pillar of HIV prevention for UNAIDS. Integrated strategies to address the gender norms, relations and inequities that underlie both violence against women and HIV/AIDS are needed. However there is limited evidence about the potential impact of different intervention models. This protocol describes the SASA! an evaluation of a community mobilisation intervention to prevent violence against women and reduce HIV/AIDS risk in Kampala, Uganda. The SASA! STUDY is a pair-matched cluster randomised controlled trial being conducted in eight communities in Kampala. It is designed to assess the community-level impact of the SASA! intervention on the following six primary outcomes: attitudes towards the acceptability of violence against women and the acceptability of a woman refusing sex (among male and female community members); past year experience of physical intimate partner violence and sexual intimate partner violence (among females); community responses to women experiencing violence (among women reporting past year physical/sexual partner violence); and past year concurrency of sexual partners (among males). 1583 women and men (aged 18-49 years) were surveyed in intervention and control communities prior to intervention implementation in 2007/8. A follow-up cross-sectional survey of community members will take place in 2012. The primary analysis will be an adjusted cluster-level intention to treat analysis, comparing outcomes in intervention and control communities at follow-up. Complementary monitoring and evaluation and qualitative research will be used to explore and describe the process of intervention implementation and the pathways through which change is achieved. This is one of few cluster randomised trials globally to assess

  18. Effectiveness of a multifaceted implementation strategy on physicians? referral behavior to an evidence-based psychosocial intervention in dementia: a cluster randomized controlled trial

    OpenAIRE

    D?pp, Carola ME; Graff, Maud JL; Teerenstra, Steven; Nijhuis-van der Sanden, Maria WG; Olde Rikkert, Marcel GM; Vernooij-Dassen, Myrra JFJ

    2013-01-01

    BACKGROUND: To evaluate the effectiveness of a multifaceted implementation strategy on physicians' referral rate to and knowledge on the community occupational therapy in dementia program (COTiD program). METHODS: A cluster randomized controlled trial with 28 experimental and 17 control clusters was conducted. Cluster included a minimum of one physician, one manager, and two occupational therapists. In the control group physicians and managers received no interventions and occupational therap...

  19. Statistical mechanics of semi-supervised clustering in sparse graphs

    International Nuclear Information System (INIS)

    Ver Steeg, Greg; Galstyan, Aram; Allahverdyan, Armen E

    2011-01-01

    We theoretically study semi-supervised clustering in sparse graphs in the presence of pair-wise constraints on the cluster assignments of nodes. We focus on bi-cluster graphs and study the impact of semi-supervision for varying constraint density and overlap between the clusters. Recent results for unsupervised clustering in sparse graphs indicate that there is a critical ratio of within-cluster and between-cluster connectivities below which clusters cannot be recovered with better than random accuracy. The goal of this paper is to examine the impact of pair-wise constraints on the clustering accuracy. Our results suggest that the addition of constraints does not provide automatic improvement over the unsupervised case. When the density of the constraints is sufficiently small, their only impact is to shift the detection threshold while preserving the criticality. Conversely, if the density of (hard) constraints is above the percolation threshold, the criticality is suppressed and the detection threshold disappears

  20. Equilibrium cluster fluids: Pair interactions via inverse design

    OpenAIRE

    Jadrich, Ryan B.; Bollinger, Jonathan A.; Lindquist, Beth A.; Truskett, Thomas M.

    2015-01-01

    Inverse methods of statistical mechanics are becoming productive tools in the design of materials with specific microstructures or properties. While initial studies have focused on solid-state design targets (e.g, assembly of colloidal superlattices), one can alternatively design fluid states with desired morphologies. This work addresses the latter and demonstrates how a simple iterative Boltzmann inversion strategy can be used to determine the isotropic pair potential that reproduces the ra...

  1. A structural multidisciplinary approach to depression management in nursing-home residents: a multicentre, stepped-wedge cluster-randomised trial

    NARCIS (Netherlands)

    Leontjevas, R.; Gerritsen, D.L.; Smalbrugge, M.; Teerenstra, S.; Vernooij-Dassen, M.J.F.J.; Koopmans, R.T.C.M.

    2013-01-01

    BACKGROUND: Depression in nursing-home residents is often under-recognised. We aimed to establish the effectiveness of a structural approach to its management. METHODS: Between May 15, 2009, and April 30, 2011, we undertook a multicentre, stepped-wedge cluster-randomised trial in four provinces of

  2. Point-of-care cluster randomized trial in stroke secondary prevention using electronic health records.

    Science.gov (United States)

    Dregan, Alex; van Staa, Tjeerd P; McDermott, Lisa; McCann, Gerard; Ashworth, Mark; Charlton, Judith; Wolfe, Charles D A; Rudd, Anthony; Yardley, Lucy; Gulliford, Martin C; Trial Steering Committee

    2014-07-01

    The aim of this study was to evaluate whether the remote introduction of electronic decision support tools into family practices improves risk factor control after first stroke. This study also aimed to develop methods to implement cluster randomized trials in stroke using electronic health records. Family practices were recruited from the UK Clinical Practice Research Datalink and allocated to intervention and control trial arms by minimization. Remotely installed, electronic decision support tools promoted intensified secondary prevention for 12 months with last measure of systolic blood pressure as the primary outcome. Outcome data from electronic health records were analyzed using marginal models. There were 106 Clinical Practice Research Datalink family practices allocated (intervention, 53; control, 53), with 11 391 (control, 5516; intervention, 5875) participants with acute stroke ever diagnosed. Participants at trial practices had similar characteristics as 47,887 patients with stroke at nontrial practices. During the intervention period, blood pressure values were recorded in the electronic health records for 90% and cholesterol values for 84% of participants. After intervention, the latest mean systolic blood pressure was 131.7 (SD, 16.8) mm Hg in the control trial arm and 131.4 (16.7) mm Hg in the intervention trial arm, and adjusted mean difference was -0.56 mm Hg (95% confidence interval, -1.38 to 0.26; P=0.183). The financial cost of the trial was approximately US $22 per participant, or US $2400 per family practice allocated. Large pragmatic intervention studies may be implemented at low cost by using electronic health records. The intervention used in this trial was not found to be effective, and further research is needed to develop more effective intervention strategies. http://www.controlled-trials.com. Current Controlled Trials identifier: ISRCTN35701810. © 2014 American Heart Association, Inc.

  3. A pragmatic cluster randomised trial evaluating three implementation interventions

    Directory of Open Access Journals (Sweden)

    Rycroft-Malone Jo

    2012-08-01

    Full Text Available Abstract Background Implementation research is concerned with bridging the gap between evidence and practice through the study of methods to promote the uptake of research into routine practice. Good quality evidence has been summarised into guideline recommendations to show that peri-operative fasting times could be considerably shorter than patients currently experience. The objective of this trial was to evaluate the effectiveness of three strategies for the implementation of recommendations about peri-operative fasting. Methods A pragmatic cluster randomised trial underpinned by the PARIHS framework was conducted during 2006 to 2009 with a national sample of UK hospitals using time series with mixed methods process evaluation and cost analysis. Hospitals were randomised to one of three interventions: standard dissemination (SD of a guideline package, SD plus a web-based resource championed by an opinion leader, and SD plus plan-do-study-act (PDSA. The primary outcome was duration of fluid fast prior to induction of anaesthesia. Secondary outcomes included duration of food fast, patients’ experiences, and stakeholders’ experiences of implementation, including influences. ANOVA was used to test differences over time and interventions. Results Nineteen acute NHS hospitals participated. Across timepoints, 3,505 duration of fasting observations were recorded. No significant effect of the interventions was observed for either fluid or food fasting times. The effect size was 0.33 for the web-based intervention compared to SD alone for the change in fluid fasting and was 0.12 for PDSA compared to SD alone. The process evaluation showed different types of impact, including changes to practices, policies, and attitudes. A rich picture of the implementation challenges emerged, including inter-professional tensions and a lack of clarity for decision-making authority and responsibility. Conclusions This was a large, complex study and one of the first

  4. A cluster-based randomized controlled trial promoting community participation in arsenic mitigation efforts in Bangladesh

    OpenAIRE

    George, Christine Marie; van Geen, Alexander; Slavkovich, Vesna; Singha, Ashit; Levy, Diane; Islam, Tariqul; Ahmed, Kazi Matin; Moon-Howard, Joyce; Tarozzi, Alessandro; Liu, Xinhua; Factor-Litvak, Pam; Graziano, Joseph

    2012-01-01

    Abstract Objective To reduce arsenic (As) exposure, we evaluated the effectiveness of training community members to perform water arsenic (WAs) testing and provide As education compared to sending representatives from outside communities to conduct these tasks. Methods We conducted a cluster based randomized controlled trial of 20 villages in Singair, Bangladesh. Fifty eligible respondents were randomly selected in each village. In 10 villages, a community member provided As education and WAs...

  5. Multiparticle production through isoscalar clusters

    International Nuclear Information System (INIS)

    Armburst, W.T.; Scott, D.M.

    1975-01-01

    The isoscalar cluster model for multiparticle production was extended to include clusters of A 2 meson pairs in addition to previously studied rho-rho and sigma clusters. The production of each type of cluster is given by an energy dependent Poisson distribution. The Poisson parameters determined from the charged particle multiplicity distributions indicate that the inclusion of A 2 -A 2 clusters does not improve the fit to the data. The predictions of the model for n 0 n/sub -/, f/sup 2//sub -,-/, and f/sup 2//sub 0,0/ compare favorably to the experimental values. (U.S.)

  6. Geographic analysis of vaccine uptake in a cluster-randomized controlled trial in Hue, Vietnam.

    Science.gov (United States)

    Ali, Mohammad; Thiem, Vu Dinh; Park, Jin-Kyung; Ochiai, Rion Leon; Canh, Do Gia; Danovaro-Holliday, M Carolina; Kaljee, Linda M; Clemens, John D; Acosta, Camilo J

    2007-09-01

    This paper identifies spatial patterns and predictors of vaccine uptake in a cluster-randomized controlled trial in Hue, Vietnam. Data for this study result from the integration of demographic surveillance, vaccine record, and geographic data of the study area. A multi-level cross-classified (non-hierarchical) model was used for analyzing the non-nested nature of individual's ecological data. Vaccine uptake was unevenly distributed in space and there was spatial variability among predictors of vaccine uptake. Vaccine uptake was higher among students with younger, male, or not literate family heads. Students from households with higher per-capita income were less likely to participate in the trial. Residency south of the river or further from a hospital/polyclinic was associated with higher vaccine uptake. Younger students were more likely to be vaccinated than older students in high- or low-risk areas, but not in the entire study area. The findings are important for the management of vaccine campaigns during a trial and for interpretation of disease patterns during vaccine-efficacy evaluation.

  7. Variational study of the pair hopping model

    International Nuclear Information System (INIS)

    Fazekas, P.

    1990-01-01

    We study the ground state of a Hamiltonian introduced by Kolb and Penson for modelling situations in which small electron pairs are formed. The Hamiltonian consists of a tight binding band term, and a term describing the nearest neighbour hopping of electron pairs. We give a Gutzwiller-type variational treatment, first with a single-parameter Ansatz treated in the single site Gutzwiller approximation, and then with more complicated trial wave functions, and an improved Gutzwiller approximation. The calculation yields a transition from a partially paired normal state, in which the spin susceptibility has a diminished value, into a fully paired state. (author). 16 refs, 2 figs

  8. Reducing Earth Topography Resolution for SMAP Mission Ground Tracks Using K-Means Clustering

    Science.gov (United States)

    Rizvi, Farheen

    2013-01-01

    The K-means clustering algorithm is used to reduce Earth topography resolution for the SMAP mission ground tracks. As SMAP propagates in orbit, knowledge of the radar antenna footprints on Earth is required for the antenna misalignment calibration. Each antenna footprint contains a latitude and longitude location pair on the Earth surface. There are 400 pairs in one data set for the calibration model. It is computationally expensive to calculate corresponding Earth elevation for these data pairs. Thus, the antenna footprint resolution is reduced. Similar topographical data pairs are grouped together with the K-means clustering algorithm. The resolution is reduced to the mean of each topographical cluster called the cluster centroid. The corresponding Earth elevation for each cluster centroid is assigned to the entire group. Results show that 400 data points are reduced to 60 while still maintaining algorithm performance and computational efficiency. In this work, sensitivity analysis is also performed to show a trade-off between algorithm performance versus computational efficiency as the number of cluster centroids and algorithm iterations are increased.

  9. Preventing knee injuries in adolescent female football players – design of a cluster randomized controlled trial [NCT00894595

    Directory of Open Access Journals (Sweden)

    Waldén Markus

    2009-06-01

    Full Text Available Abstract Background Knee injuries in football are common regardless of age, gender or playing level, but adolescent females seem to have the highest risk. The consequences after severe knee injury, for example anterior cruciate ligament (ACL injury, are well-known, but less is known about knee injury prevention. We have designed a cluster randomized controlled trial (RCT to evaluate the effect of a warm-up program aimed at preventing acute knee injury in adolescent female football. Methods In this cluster randomized trial 516 teams (309 clusters in eight regional football districts in Sweden with female players aged 13–17 years were randomized into an intervention group (260 teams or a control group (256 teams. The teams in the intervention group were instructed to do a structured warm-up program at two training sessions per week throughout the 2009 competitive season (April to October and those in the control group were informed to train and play as usual. Sixty-eight sports physical therapists are assigned to the clubs to assist both groups in data collection and to examine the players' acute knee injuries during the study period. Three different forms are used in the trial: (1 baseline player data form collected at the start of the trial, (2 computer-based registration form collected every month, on which one of the coaches/team leaders documents individual player exposure, and (3 injury report form on which the study therapists report acute knee injuries resulting in time loss from training or match play. The primary outcome is the incidence of ACL injury and the secondary outcomes are the incidence of any acute knee injury (except contusion and incidence of severe knee injury (defined as injury resulting in absence of more than 4 weeks. Outcome measures are assessed after the end of the 2009 season. Discussion Prevention of knee injury is beneficial for players, clubs, insurance companies, and society. If the warm-up program is proven to

  10. A matched pair cluster randomized implementation trail to measure the effectiveness of an intervention package aiming to decrease perinatal mortality and increase institution-based obstetric care among indigenous women in Guatemala: study protocol.

    Science.gov (United States)

    Kestler, Edgar; Walker, Dilys; Bonvecchio, Anabelle; de Tejada, Sandra Sáenz; Donner, Allan

    2013-03-21

    Maternal and perinatal mortality continue to be a high priority problem on the health agendas of less developed countries. Despite the progress made in the last decade to quantify the magnitude of maternal mortality, few interventions have been implemented with the intent to measure impact directly on maternal or perinatal deaths. The success of interventions implemented in less developed countries to reduce mortality has been questioned, in terms of the tendency to maintain a clinical perspective with a focus on purely medical care separate from community-based approaches that take cultural and social aspects of maternal and perinatal deaths into account. Our innovative approach utilizes both the clinical and community perspectives; moreover, our study will report the weight that each of these components may have had on reducing perinatal mortality and increasing institution-based deliveries. A matched pair cluster-randomized trial will be conducted in clinics in four rural indigenous districts with the highest maternal mortality ratios in Guatemala. The individual clinic will serve as the unit of randomization, with 15 matched pairs of control and intervention clinics composing the final sample. Three interventions will be implemented in indigenous, rural and poor populations: a simulation training program for emergency obstetric and perinatal care, increased participation of the professional midwife in strengthening the link between traditional birth attendants (TBA) and the formal health care system, and a social marketing campaign to promote institution-based deliveries. No external intervention is planned for control clinics, although enhanced monitoring, surveillance and data collection will occur throughout the study in all clinics throughout the four districts. All obstetric events occurring in any of the participating health facilities and districts during the 18 months implementation period will be included in the analysis, controlling for the cluster

  11. Functionally segregated neural substrates for arbitrary audiovisual paired-association learning.

    Science.gov (United States)

    Tanabe, Hiroki C; Honda, Manabu; Sadato, Norihiro

    2005-07-06

    To clarify the neural substrates and their dynamics during crossmodal association learning, we conducted functional magnetic resonance imaging (MRI) during audiovisual paired-association learning of delayed matching-to-sample tasks. Thirty subjects were involved in the study; 15 performed an audiovisual paired-association learning task, and the remainder completed a control visuo-visual task. Each trial consisted of the successive presentation of a pair of stimuli. Subjects were asked to identify predefined audiovisual or visuo-visual pairs by trial and error. Feedback for each trial was given regardless of whether the response was correct or incorrect. During the delay period, several areas showed an increase in the MRI signal as learning proceeded: crossmodal activity increased in unimodal areas corresponding to visual or auditory areas, and polymodal responses increased in the occipitotemporal junction and parahippocampal gyrus. This pattern was not observed in the visuo-visual intramodal paired-association learning task, suggesting that crossmodal associations might be formed by binding unimodal sensory areas via polymodal regions. In both the audiovisual and visuo-visual tasks, the MRI signal in the superior temporal sulcus (STS) in response to the second stimulus and feedback peaked during the early phase of learning and then decreased, indicating that the STS might be key to the creation of paired associations, regardless of stimulus type. In contrast to the activity changes in the regions discussed above, there was constant activity in the frontoparietal circuit during the delay period in both tasks, implying that the neural substrates for the formation and storage of paired associates are distinct from working memory circuits.

  12. Head Position in Stroke Trial (HeadPoST)--sitting-up vs lying-flat positioning of patients with acute stroke: study protocol for a cluster randomised controlled trial.

    Science.gov (United States)

    Muñoz-Venturelli, Paula; Arima, Hisatomi; Lavados, Pablo; Brunser, Alejandro; Peng, Bin; Cui, Liying; Song, Lily; Billot, Laurent; Boaden, Elizabeth; Hackett, Maree L; Heritier, Stephane; Jan, Stephen; Middleton, Sandy; Olavarría, Verónica V; Lim, Joyce Y; Lindley, Richard I; Heeley, Emma; Robinson, Thompson; Pontes-Neto, Octavio; Natsagdorj, Lkhamtsoo; Lin, Ruey-Tay; Watkins, Caroline; Anderson, Craig S

    2015-06-05

    Positioning a patient lying-flat in the acute phase of ischaemic stroke may improve recovery and reduce disability, but such a possibility has not been formally tested in a randomised trial. We therefore initiated the Head Position in Stroke Trial (HeadPoST) to determine the effects of lying-flat (0°) compared with sitting-up (≥ 30°) head positioning in the first 24 hours of hospital admission for patients with acute stroke. We plan to conduct an international, cluster randomised, crossover, open, blinded outcome-assessed clinical trial involving 140 study hospitals (clusters) with established acute stroke care programs. Each hospital will be randomly assigned to sequential policies of lying-flat (0°) or sitting-up (≥ 30°) head position as a 'business as usual' stroke care policy during the first 24 hours of admittance. Each hospital is required to recruit 60 consecutive patients with acute ischaemic stroke (AIS), and all patients with acute intracerebral haemorrhage (ICH) (an estimated average of 10), in the first randomised head position policy before crossing over to the second head position policy with a similar recruitment target. After collection of in-hospital clinical and management data and 7-day outcomes, central trained blinded assessors will conduct a telephone disability assessment with the modified Rankin Scale at 90 days. The primary outcome for analysis is a shift (defined as improvement) in death or disability on this scale. For a cluster size of 60 patients with AIS per intervention and with various assumptions including an intracluster correlation coefficient of 0.03, a sample size of 16,800 patients at 140 centres will provide 90 % power (α 0.05) to detect at least a 16 % relative improvement (shift) in an ordinal logistic regression analysis of the primary outcome. The treatment effect will also be assessed in all patients with ICH who are recruited during each treatment study period. HeadPoST is a large international clinical trial in

  13. Traveling-cluster approximation for uncorrelated amorphous systems

    International Nuclear Information System (INIS)

    Sen, A.K.; Mills, R.; Kaplan, T.; Gray, L.J.

    1984-01-01

    We have developed a formalism for including cluster effects in the one-electron Green's function for a positionally disordered (liquid or amorphous) system without any correlation among the scattering sites. This method is an extension of the technique known as the traveling-cluster approximation (TCA) originally obtained and applied to a substitutional alloy by Mills and Ratanavararaksa. We have also proved the appropriate fixed-point theorem, which guarantees, for a bounded local potential, that the self-consistent equations always converge upon iteration to a unique, Herglotz solution. To our knowledge, this is the only analytic theory for considering cluster effects. Furthermore, we have performed some computer calculations in the pair TCA, for the model case of delta-function potentials on a one-dimensional random chain. These results have been compared with ''exact calculations'' (which, in principle, take into account all cluster effects) and with the coherent-potential approximation (CPA), which is the single-site TCA. The density of states for the pair TCA clearly shows some improvement over the CPA and yet, apparently, the pair approximation distorts some of the features of the exact results

  14. A new combined strategy to implement a community occupational therapy intervention: designing a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Adang Eddy

    2011-03-01

    Full Text Available Abstract Background Even effective interventions for people with dementia and their caregivers require specific implementation efforts. A pilot study showed that the highly effective community occupational therapy in dementia (COTiD program was not implemented optimally due to various barriers. To decrease these barriers and make implementation of the program more effective a combined implementation (CI strategy was developed. In our study we will compare the effectiveness of this CI strategy with the usual educational (ED strategy. Methods In this cluster randomized, single-blinded, controlled trial, each cluster consists of at least two occupational therapists, a manager, and a physician working at Dutch healthcare organizations that deliver community occupational therapy. Forty-five clusters, stratified by healthcare setting (nursing home, hospital, mental health service, have been allocated randomly to either the intervention group (CI strategy or the control group (ED strategy. The study population consists of the professionals included in each cluster and community-dwelling people with dementia and their caregivers. The primary outcome measures are the use of community OT, the adherence of OTs to the COTiD program, and the cost effectiveness of implementing the COTiD program in outpatient care. Secondary outcome measures are patient and caregiver outcomes and knowledge of managers, physicians and OTs about the COTiD program. Discussion Implementation research is fairly new in the field of occupational therapy, making this a unique study. This study does not only evaluate the effects of the CI-strategy on professionals, but also the effects of professionals' degree of implementation on client and caregiver outcomes. Clinical trials registration NCT01117285

  15. Alpha-transfer reactions and the pairing-vibration model

    International Nuclear Information System (INIS)

    Betts, R.R.

    1977-01-01

    The pairing-vibration model with isospin is extended to include α-transfer reactions. Selection rules and expressions for transition strengths are derived and compared with experimental results for A = 40--66 nuclei. The selection rules are found to be followed quite well in the examples studied. The systematics of ground-state transition strengths are qualitatively quite well reproduced although the quantitative agreement is poor. When the changing nature of the pairing quanta is incorporated using two-particle transfer data the agreement becomes quantitatively good. Evidence is presented for clustering other than that due to pairing in 40 Ca and 44 Ti

  16. Effects of Mindfulness-Based Stress Reduction on the Mental Health of Clinical Clerkship Students: A Cluster-Randomized Controlled Trial

    NARCIS (Netherlands)

    Dijk, I. van; Lucassen, P.L.B.J.; Akkermans, R.P.; Engelen, B.G.M. van; Weel, C. van; Speckens, A.E.M.

    2017-01-01

    PURPOSE: To examine the effect of mindfulness-based stress reduction training (MBSR) on the mental health of medical students during clinical clerkships. METHOD: Between February 2011 and May 2014, the authors conducted a cluster-randomized controlled trial of clerkships as usual (CAU) and

  17. Initiating change locally in bullying and aggression through the school environment (INCLUSIVE) trial: update to cluster randomised controlled trial protocol.

    Science.gov (United States)

    Bonell, Chris; Mathiot, Anne; Allen, Elizabeth; Bevilacqua, Leonardo; Christie, Deborah; Elbourne, Diana; Fletcher, Adam; Grieve, Richard; Legood, Rosa; Scott, Stephen; Warren, Emily; Wiggins, Meg; Viner, Russell M

    2017-05-25

    Systematic reviews suggest that multi-component interventions are effective in reducing bullying victimisation and perpetration. We are undertaking a phase III randomised trial of the INCLUSIVE multi-component intervention. This trial aims to assess the effectiveness and cost-effectiveness of the INCLUSIVE intervention in reducing aggression and bullying victimisation in English secondary schools. This paper updates the original trial protocol published in 2014 (Trials 15:381, 2014) and presents the changes in the process evaluation protocol and the secondary outcome data collection. The methods are summarised as follows. cluster randomised trial. 40 state secondary schools. Outcomes assessed among the cohort of students at the end of year 7 (n = 6667) at baseline. INCLUSIVE is a multi-component school intervention including a social and emotional learning curriculum, changes to school environment (an action group comprising staff and students reviews local data on needs to review rules and policies and determine other local actions) and staff training in restorative practice. The intervention will be delivered by schools supported in the first two years by educational facilitators independent of the research team, with a third intervention year involving no external facilitation but all other elements. Comparator: normal practice. Primary: Two primary outcomes at student level assessed at baseline and at 36 months: 1. Aggressive behaviours in school: Edinburgh Study of Youth Transitions and Crime school misbehaviour subscale (ESYTC) 2. Bullying and victimisation: Gatehouse Bullying Scale (GBS) Secondary outcomes assessed at baseline, 24 and 36 months will include measures relating to the economic evaluation, psychosocial outcomes in students and staff and school-level truancy and exclusion rates. 20 schools per arm will provide 90% power to identify an effect size of 0.25 SD with a 5% significance level. Randomisation: eligible consenting schools were

  18. Does a pre-hospital emergency pathway improve early diagnosis and referral in suspected stroke patients? – Study protocol of a cluster randomised trial [ISRCTN41456865

    Directory of Open Access Journals (Sweden)

    Lori Giuliano

    2005-10-01

    Full Text Available Abstract Background Early interventions proved to be able to improve prognosis in acute stroke patients. Prompt identification of symptoms, organised timely and efficient transportation towards appropriate facilities, become essential part of effective treatment. The implementation of an evidence based pre-hospital stroke care pathway may be a method for achieving the organizational standards required to grant appropriate care. We performed a systematic search for studies evaluating the effect of pre-hospital and emergency interventions for suspected stroke patients and we found that there seems to be only a few studies on the emergency field and none about implementation of clinical pathways. We will test the hypothesis that the adoption of emergency clinical pathway improves early diagnosis and referral in suspected stroke patients. We designed a cluster randomised controlled trial (C-RCT, the most powerful study design to assess the impact of complex interventions. The study was registered in the Current Controlled Trials Register: ISRCTN41456865 – Implementation of pre-hospital emergency pathway for stroke – a cluster randomised trial. Methods/design Two-arm cluster-randomised trial (C-RCT. 16 emergency services and 14 emergency rooms were randomised either to arm 1 (comprising a training module and administration of the guideline, or to arm 2 (no intervention, current practice. Arm 1 participants (152 physicians, 280 nurses, 50 drivers attended an interactive two sessions course with continuous medical education CME credits on the contents of the clinical pathway. We estimated that around 750 patients will be met by the services in the 6 months of observation. This duration allows recruiting a sample of patients sufficient to observe a 30% improvement in the proportion of appropriate diagnoses. Data collection will be performed using current information systems. Process outcomes will be measured at the cluster level six months after the

  19. Citywide cluster randomized trial to restore blighted vacant land and its effects on violence, crime, and fear

    Science.gov (United States)

    Charles C. Branas; Eugenia South; Michelle C. Kondo; Bernadette C. Hohl; Philippe Bourgois; Douglas J. Wiebe; John M. MacDonald

    2018-01-01

    Vacant and blighted urban land is a widespread and potentially risky environmental condition encountered by millions of people on a daily basis. About 15% of the land in US cities is deemed vacant or abandoned, an area roughly the size of Switzerland. In a citywide cluster randomized controlled trial, we investigated the effects of standardized, reproducible...

  20. A Cluster Randomized Controlled Trial Testing the Effectiveness of Houvast: A Strengths-Based Intervention for Homeless Young Adults

    Science.gov (United States)

    Krabbenborg, Manon A. M.; Boersma, Sandra N.; van der Veld, William M.; van Hulst, Bente; Vollebergh, Wilma A. M.; Wolf, Judith R. L. M.

    2017-01-01

    Objective: To test the effectiveness of Houvast: a strengths-based intervention for homeless young adults. Method: A cluster randomized controlled trial was conducted with 10 Dutch shelter facilities randomly allocated to an intervention and a control group. Homeless young adults were interviewed when entering the facility and when care ended.…

  1. Three candidate double clusters in the LMC: truth or dare?

    Science.gov (United States)

    Dalessandro, Emanuele; Zocchi, Alice; Varri, Anna Lisa; Mucciarelli, Alessio; Bellazzini, Michele; Ferraro, Francesco R.; Lanzoni, Barbara; Lapenna, Emilio; Origlia, Livia

    2018-02-01

    The Large Magellanic Cloud (LMC) hosts a large number of candidate stellar cluster pairs. Binary stellar clusters provide important clues about cluster formation processes and the evolutionary history of the host galaxy. However, to properly extract and interpret this information, it is crucial to fully constrain the fraction of real binary systems and their physical properties. Here we present a detailed photometric analysis based on ESO-FORS2 images of three candidate cluster multiplets in the LMC, namely SL349-SL353, SL385-SL387-NGC 1922 and NGC 1836-BRHT4b-NGC 1839. For each cluster, we derived ages, structural parameters and morphological properties. We have also estimated the degree of filling of their Roche lobe, as an approximate tool to measure the strength of the tidal perturbations induced by the LMC. We find that the members of the possible pairs SL349-SL353 and BRHT4b-NGC 1839 have a similar age (t = 1.00 ± 0.12 Gyr and t = 140 ± 15 Myr, respectively), thus possibly hinting at a common origin of their member systems. We also find that all candidate pairs in our sample show evidence of intracluster overdensities that can be a possible indication of real binarity. Particularly interesting is the case of SL349-SL353. In fact, SL353 is relatively close to the condition of critical filling, thus suggesting that these systems might actually constitute an energetically bound pair. It is therefore key to pursue a detailed kinematic screening of such clusters, without which, at present, we do not dare making a conclusive statement about the true nature of this putative pair.

  2. Preventing knee injuries in adolescent female football players - design of a cluster randomized controlled trial [NCT00894595].

    Science.gov (United States)

    Hägglund, Martin; Waldén, Markus; Atroshi, Isam

    2009-06-23

    Knee injuries in football are common regardless of age, gender or playing level, but adolescent females seem to have the highest risk. The consequences after severe knee injury, for example anterior cruciate ligament (ACL) injury, are well-known, but less is known about knee injury prevention. We have designed a cluster randomized controlled trial (RCT) to evaluate the effect of a warm-up program aimed at preventing acute knee injury in adolescent female football. In this cluster randomized trial 516 teams (309 clusters) in eight regional football districts in Sweden with female players aged 13-17 years were randomized into an intervention group (260 teams) or a control group (256 teams). The teams in the intervention group were instructed to do a structured warm-up program at two training sessions per week throughout the 2009 competitive season (April to October) and those in the control group were informed to train and play as usual. Sixty-eight sports physical therapists are assigned to the clubs to assist both groups in data collection and to examine the players' acute knee injuries during the study period. Three different forms are used in the trial: (1) baseline player data form collected at the start of the trial, (2) computer-based registration form collected every month, on which one of the coaches/team leaders documents individual player exposure, and (3) injury report form on which the study therapists report acute knee injuries resulting in time loss from training or match play. The primary outcome is the incidence of ACL injury and the secondary outcomes are the incidence of any acute knee injury (except contusion) and incidence of severe knee injury (defined as injury resulting in absence of more than 4 weeks). Outcome measures are assessed after the end of the 2009 season. Prevention of knee injury is beneficial for players, clubs, insurance companies, and society. If the warm-up program is proven to be effective in reducing the incidence of knee

  3. THE EVOLUTION OF PROTOPLANETARY DISKS IN THE ARCHES CLUSTER

    International Nuclear Information System (INIS)

    Olczak, C.; Kaczmarek, T.; Pfalzner, S.; Harfst, S.; Portegies Zwart, S.

    2012-01-01

    Most stars form in a cluster environment. These stars are initially surrounded by disks from which potentially planetary systems form. Of all cluster environments, starburst clusters are probably the most hostile for planetary systems in our Galaxy. The intense stellar radiation and extreme density favor rapid destruction of circumstellar disks via photoevaporation and stellar encounters. Evolving a virialized model of the Arches cluster in the Galactic tidal field, we investigate the effect of stellar encounters on circumstellar disks in a prototypical starburst cluster. Despite its proximity to the deep gravitational potential of the Galactic center, only a moderate fraction of members escapes to form an extended pair of tidal tails. Our simulations show that encounters destroy one-third of the circumstellar disks in the cluster core within the first 2.5 Myr of evolution, preferentially affecting the least and most massive stars. A small fraction of these events causes rapid ejection and the formation of a weaker second pair of tidal tails that is overpopulated by disk-poor stars. Two predictions arise from our study. (1) If not destroyed by photoevaporation protoplanetary disks of massive late B- and early O-type stars represent the most likely hosts of planet formation in starburst clusters. (2) Multi-epoch K- and L-band photometry of the Arches cluster would provide the kinematically selected membership sample required to detect the additional pair of disk-poor tidal tails.

  4. A flexible algorithm for calculating pair interactions on SIMD architectures

    Science.gov (United States)

    Páll, Szilárd; Hess, Berk

    2013-12-01

    Calculating interactions or correlations between pairs of particles is typically the most time-consuming task in particle simulation or correlation analysis. Straightforward implementations using a double loop over particle pairs have traditionally worked well, especially since compilers usually do a good job of unrolling the inner loop. In order to reach high performance on modern CPU and accelerator architectures, single-instruction multiple-data (SIMD) parallelization has become essential. Avoiding memory bottlenecks is also increasingly important and requires reducing the ratio of memory to arithmetic operations. Moreover, when pairs only interact within a certain cut-off distance, good SIMD utilization can only be achieved by reordering input and output data, which quickly becomes a limiting factor. Here we present an algorithm for SIMD parallelization based on grouping a fixed number of particles, e.g. 2, 4, or 8, into spatial clusters. Calculating all interactions between particles in a pair of such clusters improves data reuse compared to the traditional scheme and results in a more efficient SIMD parallelization. Adjusting the cluster size allows the algorithm to map to SIMD units of various widths. This flexibility not only enables fast and efficient implementation on current CPUs and accelerator architectures like GPUs or Intel MIC, but it also makes the algorithm future-proof. We present the algorithm with an application to molecular dynamics simulations, where we can also make use of the effective buffering the method introduces.

  5. Simulation-based team training for multi-professional obstetric care teams to improve patient outcome : a multicentre, cluster randomised controlled trial

    NARCIS (Netherlands)

    Fransen, A F; van de Ven, J; Schuit, E; van Tetering, Aac; Mol, B W; Oei, S G

    OBJECTIVE: To investigate whether simulation-based obstetric team training in a simulation centre improves patient outcome. DESIGN: Multicentre, open, cluster randomised controlled trial. SETTING: Obstetric units in the Netherlands. POPULATION: Women with a singleton pregnancy beyond 24 weeks of

  6. Determination of subjective similarity for pairs of masses and pairs of clustered microcalcifications on mammograms: Comparison of similarity ranking scores and absolute similarity ratings

    International Nuclear Information System (INIS)

    Muramatsu, Chisako; Li Qiang; Schmidt, Robert A.; Shiraishi, Junji; Suzuki, Kenji; Newstead, Gillian M.; Doi, Kunio

    2007-01-01

    The presentation of images that are similar to that of an unknown lesion seen on a mammogram may be helpful for radiologists to correctly diagnose that lesion. For similar images to be useful, they must be quite similar from the radiologists' point of view. We have been trying to quantify the radiologists' impression of similarity for pairs of lesions and to establish a ''gold standard'' for development and evaluation of a computerized scheme for selecting such similar images. However, it is considered difficult to reliably and accurately determine similarity ratings, because they are subjective. In this study, we compared the subjective similarities obtained by two different methods, an absolute rating method and a 2-alternative forced-choice (2AFC) method, to demonstrate that reliable similarity ratings can be determined by the responses of a group of radiologists. The absolute similarity ratings were previously obtained for pairs of masses and pairs of microcalcifications from five and nine radiologists, respectively. In this study, similarity ranking scores for eight pairs of masses and eight pairs of microcalcifications were determined by use of the 2AFC method. In the first session, the eight pairs of masses and eight pairs of microcalcifications were grouped and compared separately for determining the similarity ranking scores. In the second session, another similarity ranking score was determined by use of mixed pairs, i.e., by comparison of the similarity of a mass pair with that of a calcification pair. Four pairs of masses and four pairs of microcalcifications were grouped together to create two sets of eight pairs. The average absolute similarity ratings and the average similarity ranking scores showed very good correlations in the first study (Pearson's correlation coefficients: 0.94 and 0.98 for masses and microcalcifications, respectively). Moreover, in the second study, the correlations between the absolute ratings and the ranking scores were also

  7. Treating sub-valence correlation effects in domain based pair natural orbital coupled cluster calculations: an out-of-the-box approach

    KAUST Repository

    Bistoni, Giovanni

    2017-06-12

    The validity of the main approximations used in canonical and domain based pair natural orbital coupled cluster methods (CCSD(T) and DLPNO-CCSD(T), respectively) in standard chemical applications is discussed. In particular, we investigate the dependence of the results on the number of electrons included in the correlation treatment in frozen-core (FC) calculations and on the main threshold governing the accuracy of DLPNO all-electron (AE) calculations. Initially, scalar relativistic orbital energies for the ground state of the atoms from Li to Rn in the periodic table are calculated. An energy criterion is applied for determining the orbitals that can be excluded from the correlation treatment in FC coupled cluster calculations without significant loss of accuracy. The heterolytic dissociation energy (HDE) of a series of metal compounds (LiF, NaF, AlF3, CaF2, CuF, GaF3, YF3, AgF, InF3, HfF4 and AuF) is calculated at the canonical CCSD(T) level, and the dependence of the results on the number of correlated electrons is investigated. Although for many of the studied reactions sub-valence correlation effects contribute significantly to the HDE, the use of an energy criterion permits a conservative definition of the size of the core, allowing FC calculations to be performed in a black-box fashion while retaining chemical accuracy. A comparison of the CCSD and the DLPNO-CCSD methods in describing the core-core, core-valence and valence-valence components of the correlation energy is given. It is found that more conservative thresholds must be used for electron pairs containing at least one core electron in order to achieve high accuracy in AE DLPNO-CCSD calculations relative to FC calculations. With the new settings, the DLPNO-CCSD method reproduces canonical CCSD results in both AE and FC calculations with the same accuracy.

  8. Treating sub-valence correlation effects in domain based pair natural orbital coupled cluster calculations: an out-of-the-box approach

    KAUST Repository

    Bistoni, Giovanni; Riplinger, Christoph; Minenkov, Yury; Cavallo, Luigi; Auer, Alexander A.; Neese, Frank

    2017-01-01

    The validity of the main approximations used in canonical and domain based pair natural orbital coupled cluster methods (CCSD(T) and DLPNO-CCSD(T), respectively) in standard chemical applications is discussed. In particular, we investigate the dependence of the results on the number of electrons included in the correlation treatment in frozen-core (FC) calculations and on the main threshold governing the accuracy of DLPNO all-electron (AE) calculations. Initially, scalar relativistic orbital energies for the ground state of the atoms from Li to Rn in the periodic table are calculated. An energy criterion is applied for determining the orbitals that can be excluded from the correlation treatment in FC coupled cluster calculations without significant loss of accuracy. The heterolytic dissociation energy (HDE) of a series of metal compounds (LiF, NaF, AlF3, CaF2, CuF, GaF3, YF3, AgF, InF3, HfF4 and AuF) is calculated at the canonical CCSD(T) level, and the dependence of the results on the number of correlated electrons is investigated. Although for many of the studied reactions sub-valence correlation effects contribute significantly to the HDE, the use of an energy criterion permits a conservative definition of the size of the core, allowing FC calculations to be performed in a black-box fashion while retaining chemical accuracy. A comparison of the CCSD and the DLPNO-CCSD methods in describing the core-core, core-valence and valence-valence components of the correlation energy is given. It is found that more conservative thresholds must be used for electron pairs containing at least one core electron in order to achieve high accuracy in AE DLPNO-CCSD calculations relative to FC calculations. With the new settings, the DLPNO-CCSD method reproduces canonical CCSD results in both AE and FC calculations with the same accuracy.

  9. The effectiveness of xylitol in a school-based cluster-randomized clinical trial.

    Science.gov (United States)

    Lee, Wonik; Spiekerman, Charles; Heima, Masahiro; Eggertsson, Hafsteinn; Ferretti, Gerald; Milgrom, Peter; Nelson, Suchitra

    2015-01-01

    The purpose of this double-blind, cluster-randomized clinical trial was to examine the effects of xylitol gummy bear snacks on dental caries progression in primary and permanent teeth of inner-city school children. A total of 562 children aged 5-6 years were recruited from five elementary schools in East Cleveland, Ohio. Children were randomized by classroom to receive xylitol (7.8 g/day) or placebo (inulin fiber 20 g/day) gummy bears. Gummy bears were given three times per day for the 9-month kindergarten year within a supervised school environment. Children in both groups also received oral health education, toothbrush and fluoridated toothpaste, topical fluoride varnish treatment and dental sealants. The numbers of new decayed, missing, and filled surfaces for primary teeth (dmfs) and permanent teeth (DMFS) from baseline to the middle of 2nd grade (exit exam) were compared between the treatment (xylitol/placebo) groups using an optimally-weighted permutation test for cluster-randomized data. The mean new d(3-6)mfs at the exit exam was 5.0 ± 7.6 and 4.0 ± 6.5 for the xylitol and placebo group, respectively. Similarly, the mean new D(3-6)MFS was 0.38 ± 0.88 and 0.48 ± 1.39 for the xylitol and placebo group, respectively. The adjusted mean difference between the two groups was not statistically significant: new d(3-6)mfs: mean 0.4, 95% CI -0.25, 0.8), and new D(3-6)MFS: mean 0.16, 95% CI -0.16, 0.43. Xylitol consumption did not have additional benefit beyond other preventive measures. Caries progression in the permanent teeth of both groups was minimal, suggesting that other simultaneous prevention modalities may have masked the possible beneficial effects of xylitol in this trial. © 2014 S. Karger AG, Basel.

  10. Clusters of Insomnia Disorder: An Exploratory Cluster Analysis of Objective Sleep Parameters Reveals Differences in Neurocognitive Functioning, Quantitative EEG, and Heart Rate Variability

    Science.gov (United States)

    Miller, Christopher B.; Bartlett, Delwyn J.; Mullins, Anna E.; Dodds, Kirsty L.; Gordon, Christopher J.; Kyle, Simon D.; Kim, Jong Won; D'Rozario, Angela L.; Lee, Rico S.C.; Comas, Maria; Marshall, Nathaniel S.; Yee, Brendon J.; Espie, Colin A.; Grunstein, Ronald R.

    2016-01-01

    Study Objectives: To empirically derive and evaluate potential clusters of Insomnia Disorder through cluster analysis from polysomnography (PSG). We hypothesized that clusters would differ on neurocognitive performance, sleep-onset measures of quantitative (q)-EEG and heart rate variability (HRV). Methods: Research volunteers with Insomnia Disorder (DSM-5) completed a neurocognitive assessment and overnight PSG measures of total sleep time (TST), wake time after sleep onset (WASO), and sleep onset latency (SOL) were used to determine clusters. Results: From 96 volunteers with Insomnia Disorder, cluster analysis derived at least two clusters from objective sleep parameters: Insomnia with normal objective sleep duration (I-NSD: n = 53) and Insomnia with short sleep duration (I-SSD: n = 43). At sleep onset, differences in HRV between I-NSD and I-SSD clusters suggest attenuated parasympathetic activity in I-SSD (P insomnia clusters derived from cluster analysis differ in sleep onset HRV. Preliminary data suggest evidence for three clusters in insomnia with differences for sustained attention and sleep-onset q-EEG. Clinical Trial Registration: Insomnia 100 sleep study: Australia New Zealand Clinical Trials Registry (ANZCTR) identification number 12612000049875. URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=347742. Citation: Miller CB, Bartlett DJ, Mullins AE, Dodds KL, Gordon CJ, Kyle SD, Kim JW, D'Rozario AL, Lee RS, Comas M, Marshall NS, Yee BJ, Espie CA, Grunstein RR. Clusters of Insomnia Disorder: an exploratory cluster analysis of objective sleep parameters reveals differences in neurocognitive functioning, quantitative EEG, and heart rate variability. SLEEP 2016;39(11):1993–2004. PMID:27568796

  11. Sparse maps—A systematic infrastructure for reduced-scaling electronic structure methods. II. Linear scaling domain based pair natural orbital coupled cluster theory

    International Nuclear Information System (INIS)

    Riplinger, Christoph; Pinski, Peter; Becker, Ute; Neese, Frank; Valeev, Edward F.

    2016-01-01

    Domain based local pair natural orbital coupled cluster theory with single-, double-, and perturbative triple excitations (DLPNO-CCSD(T)) is a highly efficient local correlation method. It is known to be accurate and robust and can be used in a black box fashion in order to obtain coupled cluster quality total energies for large molecules with several hundred atoms. While previous implementations showed near linear scaling up to a few hundred atoms, several nonlinear scaling steps limited the applicability of the method for very large systems. In this work, these limitations are overcome and a linear scaling DLPNO-CCSD(T) method for closed shell systems is reported. The new implementation is based on the concept of sparse maps that was introduced in Part I of this series [P. Pinski, C. Riplinger, E. F. Valeev, and F. Neese, J. Chem. Phys. 143, 034108 (2015)]. Using the sparse map infrastructure, all essential computational steps (integral transformation and storage, initial guess, pair natural orbital construction, amplitude iterations, triples correction) are achieved in a linear scaling fashion. In addition, a number of additional algorithmic improvements are reported that lead to significant speedups of the method. The new, linear-scaling DLPNO-CCSD(T) implementation typically is 7 times faster than the previous implementation and consumes 4 times less disk space for large three-dimensional systems. For linear systems, the performance gains and memory savings are substantially larger. Calculations with more than 20 000 basis functions and 1000 atoms are reported in this work. In all cases, the time required for the coupled cluster step is comparable to or lower than for the preceding Hartree-Fock calculation, even if this is carried out with the efficient resolution-of-the-identity and chain-of-spheres approximations. The new implementation even reduces the error in absolute correlation energies by about a factor of two, compared to the already accurate

  12. Dental care resistance prevention and antibiotic prescribing modification-the cluster-randomised controlled DREAM trial.

    Science.gov (United States)

    Löffler, Christin; Böhmer, Femke; Hornung, Anne; Lang, Hermann; Burmeister, Ulrike; Podbielski, Andreas; Wollny, Anja; Kundt, Günther; Altiner, Attila

    2014-02-22

    Bacterial resistance development is one of the most urgent problems in healthcare worldwide. In Europe, dentistry accounts for a comparatively high amount of antibiotic prescriptions. In light of increasing levels of bacterial resistance, this development is alarming. So far, very few interventional studies have been performed, and further research is urgently needed. By means of a complex educational intervention, the DREAM trial aims at optimising antibiotic prescribing behaviour of general dentists in Germany. This is a cluster-randomised controlled trial, where each cluster consists of one dental practice and all of its patients in a defined period. Participants are general dentists practicing in the German region of Mecklenburg-Western Pomerania. Randomisation takes place after baseline data collection (6 months) and will be stratified by the antibiotic prescribing rates of the participating dental practices. Dentists randomised into the intervention group will participate in a complex small group educational seminar that aims at: increasing knowledge on bacterial resistance, pharmacology, and prophylaxis of infectious endocarditis; increasing awareness of dentist-patient communication using video-taped vignettes of dentist-patient communication on antibiotic treatment; improving collaboration between general dentists, general practitioners, and practice-based cardiologists on the necessity of antibiotic prophylaxis; enhancing awareness of the dentists' own prescribing habits by providing antibiotic prescribing feedback; and increasing patient knowledge on antibiotic treatment by providing patient-centred information material on antibiotic prophylaxis of endocarditis. The dentists randomised into the control group will not receive any educational programme and provide care as usual. Primary outcome is the overall antibiotic prescribing rate measured at T1 (period of six months after intervention). In a subgroup of adult patients affected by odontogenic

  13. A cluster-randomized, placebo-controlled, maternal vitamin A or beta-carotene supplementation trial in Bangladesh: design and methods.

    Science.gov (United States)

    Labrique, Alain B; Christian, Parul; Klemm, Rolf D W; Rashid, Mahbubur; Shamim, Abu Ahmed; Massie, Allan; Schulze, Kerry; Hackman, Andre; West, Keith P

    2011-04-21

    We present the design, methods and population characteristics of a large community trial that assessed the efficacy of a weekly supplement containing vitamin A or beta-carotene, at recommended dietary levels, in reducing maternal mortality from early gestation through 12 weeks postpartum. We identify challenges faced and report solutions in implementing an intervention trial under low-resource, rural conditions, including the importance of population choice in promoting generalizability, maintaining rigorous data quality control to reduce inter- and intra- worker variation, and optimizing efficiencies in information and resources flow from and to the field. This trial was a double-masked, cluster-randomized, dual intervention, placebo-controlled trial in a contiguous rural area of ~435 sq km with a population of ~650,000 in Gaibandha and Rangpur Districts of Northwestern Bangladesh. Approximately 120,000 married women of reproductive age underwent 5-weekly home surveillance, of whom ~60,000 were detected as pregnant, enrolled into the trial and gave birth to ~44,000 live-born infants. Upon enrollment, at ~ 9 weeks' gestation, pregnant women received a weekly oral supplement containing vitamin A (7000 ug retinol equivalents (RE)), beta-carotene (42 mg, or ~7000 ug RE) or a placebo through 12 weeks postpartum, according to prior randomized allocation of their cluster of residence. Systems described include enlistment and 5-weekly home surveillance for pregnancy based on menstrual history and urine testing, weekly supervised supplementation, periodic risk factor interviews, maternal and infant vital outcome monitoring, birth defect surveillance and clinical/biochemical substudies. The primary outcome was pregnancy-related mortality assessed for 3 months following parturition. Secondary outcomes included fetal loss due to miscarriage or stillbirth, infant mortality under three months of age, maternal obstetric and infectious morbidity, infant infectious morbidity

  14. A cluster-randomized, placebo-controlled, maternal vitamin a or beta-carotene supplementation trial in bangladesh: design and methods

    Directory of Open Access Journals (Sweden)

    Schulze Kerry

    2011-04-01

    Full Text Available Abstract Background We present the design, methods and population characteristics of a large community trial that assessed the efficacy of a weekly supplement containing vitamin A or beta-carotene, at recommended dietary levels, in reducing maternal mortality from early gestation through 12 weeks postpartum. We identify challenges faced and report solutions in implementing an intervention trial under low-resource, rural conditions, including the importance of population choice in promoting generalizability, maintaining rigorous data quality control to reduce inter- and intra- worker variation, and optimizing efficiencies in information and resources flow from and to the field. Methods This trial was a double-masked, cluster-randomized, dual intervention, placebo-controlled trial in a contiguous rural area of ~435 sq km with a population of ~650,000 in Gaibandha and Rangpur Districts of Northwestern Bangladesh. Approximately 120,000 married women of reproductive age underwent 5-weekly home surveillance, of whom ~60,000 were detected as pregnant, enrolled into the trial and gave birth to ~44,000 live-born infants. Upon enrollment, at ~ 9 weeks' gestation, pregnant women received a weekly oral supplement containing vitamin A (7000 ug retinol equivalents (RE, beta-carotene (42 mg, or ~7000 ug RE or a placebo through 12 weeks postpartum, according to prior randomized allocation of their cluster of residence. Systems described include enlistment and 5-weekly home surveillance for pregnancy based on menstrual history and urine testing, weekly supervised supplementation, periodic risk factor interviews, maternal and infant vital outcome monitoring, birth defect surveillance and clinical/biochemical substudies. Results The primary outcome was pregnancy-related mortality assessed for 3 months following parturition. Secondary outcomes included fetal loss due to miscarriage or stillbirth, infant mortality under three months of age, maternal obstetric and

  15. Clusters of Insomnia Disorder: An Exploratory Cluster Analysis of Objective Sleep Parameters Reveals Differences in Neurocognitive Functioning, Quantitative EEG, and Heart Rate Variability.

    Science.gov (United States)

    Miller, Christopher B; Bartlett, Delwyn J; Mullins, Anna E; Dodds, Kirsty L; Gordon, Christopher J; Kyle, Simon D; Kim, Jong Won; D'Rozario, Angela L; Lee, Rico S C; Comas, Maria; Marshall, Nathaniel S; Yee, Brendon J; Espie, Colin A; Grunstein, Ronald R

    2016-11-01

    To empirically derive and evaluate potential clusters of Insomnia Disorder through cluster analysis from polysomnography (PSG). We hypothesized that clusters would differ on neurocognitive performance, sleep-onset measures of quantitative ( q )-EEG and heart rate variability (HRV). Research volunteers with Insomnia Disorder (DSM-5) completed a neurocognitive assessment and overnight PSG measures of total sleep time (TST), wake time after sleep onset (WASO), and sleep onset latency (SOL) were used to determine clusters. From 96 volunteers with Insomnia Disorder, cluster analysis derived at least two clusters from objective sleep parameters: Insomnia with normal objective sleep duration (I-NSD: n = 53) and Insomnia with short sleep duration (I-SSD: n = 43). At sleep onset, differences in HRV between I-NSD and I-SSD clusters suggest attenuated parasympathetic activity in I-SSD (P insomnia clusters derived from cluster analysis differ in sleep onset HRV. Preliminary data suggest evidence for three clusters in insomnia with differences for sustained attention and sleep-onset q -EEG. Insomnia 100 sleep study: Australia New Zealand Clinical Trials Registry (ANZCTR) identification number 12612000049875. URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=347742. © 2016 Associated Professional Sleep Societies, LLC.

  16. The implementation of the serial trial intervention for pain and challenging behaviour in advanced dementia patients (STA OP!: a clustered randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Francke Anneke L

    2011-03-01

    Full Text Available Abstract Background Pain (physical discomfort and challenging behaviour are highly prevalent in nursing home residents with dementia: at any given time 45-80% of nursing home residents are in pain and up to 80% have challenging behaviour. In the USA Christine Kovach developed the serial trial intervention (STI and established that this protocol leads to less discomfort and fewer behavioural symptoms in moderate to severe dementia patients. The present study will provide insight into the effects of implementation of the Dutch version of the STI-protocol (STA OP! in comparison with a control intervention, not only on behavioural symptoms, but also on pain, depression, and quality of life. This article outlines the study protocol. Methods/Design The study is a cluster randomized controlled trial in 168 older people (aged >65 years with mild or moderate dementia living in nursing homes. The clusters, Dutch nursing homes, are randomly assigned to either the intervention condition (training and implementation of the STA OP!-protocol or the control condition (general training focusing on challenging behaviour and pain, but without the step-wise approach. Measurements take place at baseline, after 3 months (end of the STA OP! training period and after 6 months. Primary outcome measures are symptoms of challenging behaviour (measured with the Cohen-Mansfield Agitation Inventory (CMAI and the Neuropsychiatric Inventory-Nursing Home version (NPI-NH, and pain (measure with the Dutch version of the Pain Assessment Checklist for Seniors (PACSLAC-D and the Minimum Data Set of the Resident Assessment Instrument (MDS-RAI pain scale. Secondary outcome measures include symptoms of depression (Cornell and MDS-RAI depression scale, Quality of Live (Qualidem, changes in prescriptions of analgesics and psychotropic drugs, and the use of non-pharmacological comfort interventions (e.g. snoezelen, reminiscence therapy. Discussion The transfer from the American design to

  17. Protocol for Work place adjusted Intelligent physical exercise reducing Musculoskeletal pain in Shoulder and neck (VIMS: a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Feveile Helene

    2010-08-01

    Full Text Available Abstract Background Neck and shoulder complaints are common among employees in sedentary occupations characterized by intensive computer use. Specific strength training is a promising type of physical exercise for relieving neck and shoulder pain in office workers. However, the optimal combination of frequency and exercise duration, as well as the importance of exercise supervision, is unknown. The VIMS study investigates in a cluster randomized controlled design the effectiveness of different time wise combinations of specific strength training with identical accumulated volume, and the relevance of training supervision for safe and effective training. Methods/design A cluster randomized controlled trial of 20 weeks duration where employed office workers are randomized to 1 × 60 min, 3 × 20 min, 9 × 7 min per week of specific strength training with training supervision, to 3 × 20 min per week of specific strength training with a minimal amount of training supervision, or to a reference group without training. A questionnaire will be sent to 2000 employees in jobs characterized by intensive computer work. Employees with cardiovascular disease, trauma, hypertension, or serious chronic disease will be excluded. The main outcome measure is pain in the neck and shoulders at week 20. Trial Registration The trial is registered at ClinicalTrials.gov, number NCT01027390.

  18. Home-based versus mobile clinic HIV testing and counseling in rural Lesotho: a cluster-randomized trial.

    Science.gov (United States)

    Labhardt, Niklaus Daniel; Motlomelo, Masetsibi; Cerutti, Bernard; Pfeiffer, Karolin; Kamele, Mashaete; Hobbins, Michael A; Ehmer, Jochen

    2014-12-01

    The success of HIV programs relies on widely accessible HIV testing and counseling (HTC) services at health facilities as well as in the community. Home-based HTC (HB-HTC) is a popular community-based approach to reach persons who do not test at health facilities. Data comparing HB-HTC to other community-based HTC approaches are very limited. This trial compares HB-HTC to mobile clinic HTC (MC-HTC). The trial was powered to test the hypothesis of higher HTC uptake in HB-HTC campaigns than in MC-HTC campaigns. Twelve clusters were randomly allocated to HB-HTC or MC-HTC. The six clusters in the HB-HTC group received 30 1-d multi-disease campaigns (five villages per cluster) that delivered services by going door-to-door, whereas the six clusters in MC-HTC group received campaigns involving community gatherings in the 30 villages with subsequent service provision in mobile clinics. Time allocation and human resources were standardized and equal in both groups. All individuals accessing the campaigns with unknown HIV status or whose last HIV test was >12 wk ago and was negative were eligible. All outcomes were assessed at the individual level. Statistical analysis used multivariable logistic regression. Odds ratios and p-values were adjusted for gender, age, and cluster effect. Out of 3,197 participants from the 12 clusters, 2,563 (80.2%) were eligible (HB-HTC: 1,171; MC-HTC: 1,392). The results for the primary outcomes were as follows. Overall HTC uptake was higher in the HB-HTC group than in the MC-HTC group (92.5% versus 86.7%; adjusted odds ratio [aOR]: 2.06; 95% CI: 1.18-3.60; p = 0. 011). Among adolescents and adults ≥ 12 y, HTC uptake did not differ significantly between the two groups; however, in children versus 58.7%; aOR: 4.91; 95% CI: 2.41-10.0; pindividuals in the HB-HTC and in the MC-HTC arms, respectively, linked to HIV care within 1 mo after testing positive. Findings for secondary outcomes were as follows: HB-HTC reached more first-time testers

  19. A cluster randomized controlled trial of a brief tobacco cessation intervention for low-income communities in India: study protocol.

    Science.gov (United States)

    Sarkar, Bidyut K; Shahab, Lion; Arora, Monika; Lorencatto, Fabiana; Reddy, K Srinath; West, Robert

    2014-03-01

    India has 275 million adult tobacco users and tobacco use is estimated to contribute to more than a million deaths in the country each year. There is an urgent need to develop and evaluate affordable, practicable and scalable interventions to promote cessation of tobacco use. Because tobacco use is so harmful, an increase of as little as 1 percentage point in long-term quit success rates can have an important public health impact. This protocol paper describes the rationale and methods of a large randomized controlled trial which aims to evaluate the effectiveness of a brief scalable smoking cessation intervention delivered by trained health professionals as an outreach programme in poor urban communities in India. This is a pragmatic, two-arm, community-based cluster randomized controlled trial focused on tobacco users in low-income communities. The treatment arm is a brief intervention comprising brief advice including training in craving control using simple yogic breathing exercises (BA-YBA) and the control arm is very brief advice (VBA). Of a total of 32 clusters, 16 will be allocated to the intervention arm and 16 to the control arm. Each cluster will have 31 participants, making a total of 992 participants. The primary outcome measure will follow the Russell Standard: self-report of sustained abstinence for at least 6 months following the intervention confirmed at the final follow-up by salivary cotinine. This trial will inform national and international policy on delivery of scalable and affordable brief outreach interventions to promote tobacco use cessation in low resource settings where tobacco users have limited access to physicians and medications. © 2014 Society for the Study of Addiction.

  20. Optimizing polypharmacy among elderly hospital patients with chronic diseases--study protocol of the cluster randomized controlled POLITE-RCT trial.

    Science.gov (United States)

    Löffler, Christin; Drewelow, Eva; Paschka, Susanne D; Frankenstein, Martina; Eger, Julia; Jatsch, Lisa; Reisinger, Emil C; Hallauer, Johannes F; Drewelow, Bernd; Heidorn, Karen; Schröder, Helmut; Wollny, Anja; Kundt, Günther; Schmidt, Christian; Altiner, Attila

    2014-10-06

    Treatment of patients with multimorbidity is challenging. A rational reduction of long-term drugs can lead to decreased mortality, less acute hospital treatment, and a reduction of costs. Simplification of drug treatment schemes is also related to higher levels of patient satisfaction and adherence. The POLITE-RCT trial will test the effectiveness of an intervention aiming at reducing the number of prescribed long-term drugs among multimorbid and chronically ill patients. The intervention focuses on the interface between primary and secondary health care and includes a pharmacist-based, patient-centered medication review prior to the patient's discharge from hospital. The POLITE-RCT trial is a cluster randomized controlled trial. Two major secondary health care providers of Mecklenburg-Western Pomerania, Germany, take part in the study. Clusters are wards of both medical centers. All wards where patients with chronic diseases and multimorbidity are regularly treated will be included. Patients aged 65+ years who take five or more prescribed long-term drugs and who are likely to spend at least 5 days in the participating hospitals will be recruited and included consecutively. Cluster-randomization takes place after a six-month baseline data collection period. Patients of the control group receive care as usual. The independent two main primary outcomes are (1) health-related quality of life (EQ-5D) and (2) the difference in the number of prescribed long-term pharmaceutical agents between intervention and control group. The secondary outcomes are appropriateness of prescribed medication (PRISCUS list, Beers Criteria, MAI), patient satisfaction (TSQM), patient empowerment (PEF-FB-9), patient autonomy (IADL), falls, re-hospitalization, and death. The points of measurement are at admission to (T0) and discharge from hospital (T1) as well as 6 and 12 months after discharge from the hospital (T2 and T3). In 42 wards, 1,626 patients will be recruited. In case of positive

  1. Effects of unconditional and conditional cash transfers on child health and development in Zimbabwe: a cluster-randomised trial.

    Science.gov (United States)

    Robertson, Laura; Mushati, Phyllis; Eaton, Jeffrey W; Dumba, Lovemore; Mavise, Gideon; Makoni, Jeremiah; Schumacher, Christina; Crea, Tom; Monasch, Roeland; Sherr, Lorraine; Garnett, Geoffrey P; Nyamukapa, Constance; Gregson, Simon

    2013-04-13

    Cash-transfer programmes can improve the wellbeing of vulnerable children, but few studies have rigorously assessed their effectiveness in sub-Saharan Africa. We investigated the effects of unconditional cash transfers (UCTs) and conditional cash transfers (CCTs) on birth registration, vaccination uptake, and school attendance in children in Zimbabwe. We did a matched, cluster-randomised controlled trial in ten sites in Manicaland, Zimbabwe. We divided each study site into three clusters. After a baseline survey between July, and September, 2009, clusters in each site were randomly assigned to UCT, CCT, or control, by drawing of lots from a hat. Eligible households contained children younger than 18 years and satisfied at least one other criteria: head of household was younger than 18 years; household cared for at least one orphan younger than 18 years, a disabled person, or an individual who was chronically ill; or household was in poorest wealth quintile. Between January, 2010, and January, 2011, households in UCT clusters collected payments every 2 months. Households in CCT clusters could receive the same amount but were monitored for compliance with several conditions related to child wellbeing. Eligible households in all clusters, including control clusters, had access to parenting skills classes and received maize seed and fertiliser in December, 2009, and August, 2010. Households and individuals delivering the intervention were not masked, but data analysts were. The primary endpoints were proportion of children younger than 5 years with a birth certificate, proportion younger than 5 years with up-to-date vaccinations, and proportion aged 6-12 years attending school at least 80% of the time. This trial is registered with ClinicalTrials.gov, number NCT00966849. 1199 eligible households were allocated to the control group, 1525 to the UCT group, and 1319 to the CCT group. Compared with control clusters, the proportion of children aged 0-4 years with birth

  2. A community-based cluster randomised trial of safe storage to reduce pesticide self-poisoning in rural Sri Lanka

    DEFF Research Database (Denmark)

    Pearson, Melissa; Konradsen, Flemming; Gunnell, David

    2011-01-01

    . One approach to reducing access to pesticides is for households to store pesticides in lockable "safe-storage" containers. However, before this approach can be promoted, evidence is required on its effectiveness and safety. Methods/Design A community-based cluster randomised controlled trial has been...... at the 5% significance level. Secondary outcomes will include the incidence of all pesticide poisoning and total self-harm. Discussion This paper describes a large effectiveness study of a community intervention to reduce the burden of intentional poisoning in rural Sri Lanka. The study builds on a strong...... partnership between provincial health services, local and international researchers, and local communities. We discuss issues in relation to randomisation and contamination, engaging control villages, the intervention, and strategies to improve adherence. Trial Registritation The trial is registered...

  3. Restrictive versus liberal blood transfusion for acute upper gastrointestinal bleeding (TRIGGER): a pragmatic, open-label, cluster randomised feasibility trial.

    Science.gov (United States)

    Jairath, Vipul; Kahan, Brennan C; Gray, Alasdair; Doré, Caroline J; Mora, Ana; James, Martin W; Stanley, Adrian J; Everett, Simon M; Bailey, Adam A; Dallal, Helen; Greenaway, John; Le Jeune, Ivan; Darwent, Melanie; Church, Nicholas; Reckless, Ian; Hodge, Renate; Dyer, Claire; Meredith, Sarah; Llewelyn, Charlotte; Palmer, Kelvin R; Logan, Richard F; Travis, Simon P; Walsh, Timothy S; Murphy, Michael F

    2015-07-11

    Transfusion thresholds for acute upper gastrointestinal bleeding are controversial. So far, only three small, underpowered studies and one single-centre trial have been done. Findings from the single-centre trial showed reduced mortality with restrictive red blood cell (RBC) transfusion. We aimed to assess whether a multicentre, cluster randomised trial is a feasible method to substantiate or refute this finding. In this pragmatic, open-label, cluster randomised feasibility trial, done in six university hospitals in the UK, we enrolled all patients aged 18 years or older with new presentations of acute upper gastrointestinal bleeding, irrespective of comorbidity, except for exsanguinating haemorrhage. We randomly assigned hospitals (1:1) with a computer-generated randomisation sequence (random permuted block size of 6, without stratification or matching) to either a restrictive (transfusion when haemoglobin concentration fell below 80 g/L) or liberal (transfusion when haemoglobin concentration fell below 100 g/L) RBC transfusion policy. Neither patients nor investigators were masked to treatment allocation. Feasibility outcomes were recruitment rate, protocol adherence, haemoglobin concentration, RBC exposure, selection bias, and information to guide design and economic evaluation of the phase 3 trial. Main exploratory clinical outcomes were further bleeding and mortality at day 28. We did analyses on all enrolled patients for whom an outcome was available. This trial is registered, ISRCTN85757829 and NCT02105532. Between Sept 3, 2012, and March 1, 2013, we enrolled 936 patients across six hospitals (403 patients in three hospitals with a restrictive policy and 533 patients in three hospitals with a liberal policy). Recruitment rate was significantly higher for the liberal than for the restrictive policy (62% vs 55%; p=0·04). Despite some baseline imbalances, Rockall and Blatchford risk scores were identical between policies. Protocol adherence was 96% (SD 10) in

  4. Cost and cost-effectiveness of newborn home visits: findings from the Newhints cluster-randomised controlled trial in rural Ghana

    NARCIS (Netherlands)

    Pitt, Catherine; Tawiah, Theresa; Soremekun, Seyi; ten Asbroek, Augustinus H. A.; Manu, Alexander; Tawiah-Agyemang, Charlotte; Hill, Zelee; Owusu-Agyei, Seth; Kirkwood, Betty R.; Hanson, Kara

    2016-01-01

    Every year, 2·9 million newborn babies die worldwide. A meta-analysis of four cluster-randomised controlled trials estimated that home visits by trained community members in programme settings in Ghana and south Asia reduced neonatal mortality by 12% (95% CI 5-18). We aimed to estimate the costs and

  5. Stepped-wedge cluster randomised controlled trials: a generic framework including parallel and multiple-level designs.

    Science.gov (United States)

    Hemming, Karla; Lilford, Richard; Girling, Alan J

    2015-01-30

    Stepped-wedge cluster randomised trials (SW-CRTs) are being used with increasing frequency in health service evaluation. Conventionally, these studies are cross-sectional in design with equally spaced steps, with an equal number of clusters randomised at each step and data collected at each and every step. Here we introduce several variations on this design and consider implications for power. One modification we consider is the incomplete cross-sectional SW-CRT, where the number of clusters varies at each step or where at some steps, for example, implementation or transition periods, data are not collected. We show that the parallel CRT with staggered but balanced randomisation can be considered a special case of the incomplete SW-CRT. As too can the parallel CRT with baseline measures. And we extend these designs to allow for multiple layers of clustering, for example, wards within a hospital. Building on results for complete designs, power and detectable difference are derived using a Wald test and obtaining the variance-covariance matrix of the treatment effect assuming a generalised linear mixed model. These variations are illustrated by several real examples. We recommend that whilst the impact of transition periods on power is likely to be small, where they are a feature of the design they should be incorporated. We also show examples in which the power of a SW-CRT increases as the intra-cluster correlation (ICC) increases and demonstrate that the impact of the ICC is likely to be smaller in a SW-CRT compared with a parallel CRT, especially where there are multiple levels of clustering. Finally, through this unified framework, the efficiency of the SW-CRT and the parallel CRT can be compared. © 2014 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

  6. Community interventions to reduce child mortality in Dhanusha, Nepal: study protocol for a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Costello Anthony

    2011-06-01

    Full Text Available Abstract Background Neonatal mortality remains high in rural Nepal. Previous work suggests that local women's groups can effect significant improvement through community mobilisation. The possibility of identification and management of newborn infections by community-based workers has also arisen. Methods/Design The objective of this trial is to evaluate the effects on newborn health of two community-based interventions involving Female Community Health Volunteers. MIRA Dhanusha community groups: a participatory intervention with women's groups. MIRA Dhanusha sepsis management: training of community volunteers in the recognition and management of neonatal sepsis. The study design is a cluster randomized controlled trial involving 60 village development committee clusters allocated 1:1 to two interventions in a factorial design. MIRA Dhanusha community groups: Female Community Health Volunteers (FCHVs are supported in convening monthly women's groups. Nine groups per cluster (270 in total work through two action research cycles in which they (i identify local issues around maternity, newborn health and nutrition, (ii prioritise key problems, (iii develop strategies to address them, (iv implement the strategies, and (v evaluate their success. Cycle 1 focuses on maternal and newborn health and cycle 2 on nutrition in pregnancy and infancy and associated postpartum care practices. MIRA Dhanusha sepsis management: FCHVs are trained to care for vulnerable newborn infants. They (i identify local births, (ii identify low birth weight infants, (iii identify possible newborn infection, (iv manage the process of treatment with oral antibiotics and referral to a health facility to receive parenteral gentamicin, and (v follow up infants and support families. Primary outcome: neonatal mortality rates. Secondary outcomes: MIRA Dhanusha community group: stillbirth, infant and under-two mortality rates, care practices and health care seeking behaviour, maternal

  7. Return-to-work intervention versus usual care for sick-listed employees : Health-economic investment appraisal alongside a cluster randomised trial

    NARCIS (Netherlands)

    Lokman, S.; Volker, D.; Zijlstra-Vlasveld, M.C.; Brouwers, E.P.M.; Boon, B.; Beekman, A.T.; Smit, F.; van der Feltz-Cornelis, C.M.

    2017-01-01

    To evaluate the health-economic costs and benefits of a guided eHealth intervention (E-health module embedded in Collaborative Occupational healthcare (ECO)) encouraging sick-listed employees to a faster return to work. A two-armed cluster randomised trial with occupational physicians (OPs) (n=62),

  8. Evaluator-blinded trial evaluating nurse-led immunotherapy DEcision Coaching In persons with relapsing-remitting Multiple Sclerosis (DECIMS) and accompanying process evaluation: study protocol for a cluster randomised controlled trial.

    Science.gov (United States)

    Rahn, Anne Christin; Köpke, Sascha; Kasper, Jürgen; Vettorazzi, Eik; Mühlhauser, Ingrid; Heesen, Christoph

    2015-03-21

    Multiple sclerosis is a chronic neurological condition usually starting in early adulthood and regularly leading to severe disability. Immunotherapy options are growing in number and complexity, while costs of treatments are high and adherence rates remain low. Therefore, treatment decision-making has become more complex for patients. Structured decision coaching, based on the principles of evidence-based patient information and shared decision-making, has the potential to facilitate participation of individuals in the decision-making process. This cluster randomised controlled trial follows the assumption that decision coaching by trained nurses, using evidence-based patient information and preference elicitation, will facilitate informed choices and induce higher decision quality, as well as better decisional adherence. The decision coaching programme will be evaluated through an evaluator-blinded superiority cluster randomised controlled trial, including 300 patients with suspected or definite relapsing-remitting multiple sclerosis, facing an immunotherapy decision. The clusters are 12 multiple sclerosis outpatient clinics in Germany. Further, the trial will be accompanied by a mixed-methods process evaluation and a cost-effectiveness study. Nurses in the intervention group will be trained in shared decision-making, coaching, and evidence-based patient information principles. Patients who meet the inclusion criteria will receive decision coaching (intervention group) with up to three face-to-face coaching sessions with a trained nurse (decision coach) or counselling as usual (control group). Patients in both groups will be given access to an evidence-based online information tool. The primary outcome is 'informed choice' after six months, assessed with the multi-dimensional measure of informed choice including the sub-dimensions risk knowledge (questionnaire), attitude concerning immunotherapy (questionnaire), and immunotherapy uptake (telephone survey

  9. Trial for the Prevention of Depression (TriPoD) in final-year secondary students: study protocol for a cluster randomised controlled trial.

    Science.gov (United States)

    Perry, Yael; Calear, Alison L; Mackinnon, Andrew; Batterham, Philip J; Licinio, Julio; King, Catherine; Thomsen, Noel; Scott, Jan; Donker, Tara; Merry, Sally; Fleming, Theresa; Stasiak, Karolina; Werner-Seidler, Aliza; Christensen, Helen

    2015-10-12

    Evidence suggests that current treatments cannot fully alleviate the burden of disease associated with depression but that prevention approaches offer a promising opportunity to further reduce this burden. Adolescence is a critical period in the development of mental illness, and final school examinations are a significant and nearly universal stressor that may act as a trigger for mental health difficulties such as depression. The aim of the present trial is to investigate the impact of SPARX-R, an online, gamified intervention based on cognitive behavioural principles, on the prevention of depression in secondary school students before their final examinations. Government, independent and Catholic secondary schools in New South Wales, Australia, will be recruited to participate in the trial. All students enrolled in their final year of high school (year 12) in participating schools will be invited to participate. To account for possible attrition, the target sample size was set at 1600 participants across 30 schools. Participating schools will be cluster randomised at the school level to receive either SPARX-R or lifeSTYLE, an attention-controlled placebo comparator. The control intervention is an online program aimed at maintaining a healthy lifestyle. The primary outcome will be symptoms of depression, and secondary outcomes will include symptoms of anxiety, suicidal ideation and behaviours, stigma and academic performance. Additional measures of cost-effectiveness, as well as process variables (e.g., adherence, acceptability) and potential predictors of response to treatment, will be collected. Consenting parents will be invited to complete measures regarding their own mental health and expectations for their child. Assessments will be conducted pre- and post-intervention and at 6- and 18-month follow-up. Primary analyses will compare changes in levels of depressive symptomatology for the intervention group relative to the attention control condition using

  10. Community resource centres to improve the health of women and children in Mumbai slums: study protocol for a cluster randomized controlled trial.

    Science.gov (United States)

    Shah More, Neena; Das, Sushmita; Bapat, Ujwala; Rajguru, Mahesh; Alcock, Glyn; Joshi, Wasundhara; Pantvaidya, Shanti; Osrin, David

    2013-05-08

    The trial addresses the general question of whether community resource centers run by a non-government organization improve the health of women and children in slums. The resource centers will be run by the Society for Nutrition, Education and Health Action, and the trial will evaluate their effects on a series of public health indicators. Each resource center will be located in a vulnerable Mumbai slum area and will serve as a base for salaried community workers, supervised by officers and coordinators, to organize the collection and dissemination of health information, provision of services, home visits to identify and counsel families at risk, referral of individuals and families to appropriate services and support for their access, meetings of community members and providers, and events and campaigns on health issues. A cluster randomized controlled trial in which 20 urban slum areas with resource centers are compared with 20 control areas. Each cluster will contain approximately 600 households and randomized allocation will be in three blocked phases, of 12, 12 and 16 clusters. Any resident of an intervention cluster will be able to participate in the intervention, but the resource centers will target women and children, particularly women of reproductive age and children under 5.The outcomes will be assessed through a household census after 2 years of resource center operations. The primary outcomes are unmet need for family planning in women aged 15 to 49 years, proportion of children under 5 years of age not fully immunized for their ages, and proportion of children under 5 years of age with weight for height less than 2 standard deviations below the median for age and sex. Secondary outcomes describe adolescent pregnancies, home deliveries, receipt of conditional cash transfers for institutional delivery, other childhood anthropometric indices, use of public sector health and nutrition services, indices of infant and young child feeding, and consultation

  11. Gene cluster statistics with gene families.

    Science.gov (United States)

    Raghupathy, Narayanan; Durand, Dannie

    2009-05-01

    Identifying genomic regions that descended from a common ancestor is important for understanding the function and evolution of genomes. In distantly related genomes, clusters of homologous gene pairs are evidence of candidate homologous regions. Demonstrating the statistical significance of such "gene clusters" is an essential component of comparative genomic analyses. However, currently there are no practical statistical tests for gene clusters that model the influence of the number of homologs in each gene family on cluster significance. In this work, we demonstrate empirically that failure to incorporate gene family size in gene cluster statistics results in overestimation of significance, leading to incorrect conclusions. We further present novel analytical methods for estimating gene cluster significance that take gene family size into account. Our methods do not require complete genome data and are suitable for testing individual clusters found in local regions, such as contigs in an unfinished assembly. We consider pairs of regions drawn from the same genome (paralogous clusters), as well as regions drawn from two different genomes (orthologous clusters). Determining cluster significance under general models of gene family size is computationally intractable. By assuming that all gene families are of equal size, we obtain analytical expressions that allow fast approximation of cluster probabilities. We evaluate the accuracy of this approximation by comparing the resulting gene cluster probabilities with cluster probabilities obtained by simulating a realistic, power-law distributed model of gene family size, with parameters inferred from genomic data. Surprisingly, despite the simplicity of the underlying assumption, our method accurately approximates the true cluster probabilities. It slightly overestimates these probabilities, yielding a conservative test. We present additional simulation results indicating the best choice of parameter values for data

  12. Analytic energy derivatives for the calculation of the first-order molecular properties using the domain-based local pair-natural orbital coupled-cluster theory

    Science.gov (United States)

    Datta, Dipayan; Kossmann, Simone; Neese, Frank

    2016-09-01

    The domain-based local pair-natural orbital coupled-cluster (DLPNO-CC) theory has recently emerged as an efficient and powerful quantum-chemical method for the calculation of energies of molecules comprised of several hundred atoms. It has been demonstrated that the DLPNO-CC approach attains the accuracy of a standard canonical coupled-cluster calculation to about 99.9% of the basis set correlation energy while realizing linear scaling of the computational cost with respect to system size. This is achieved by combining (a) localized occupied orbitals, (b) large virtual orbital correlation domains spanned by the projected atomic orbitals (PAOs), and (c) compaction of the virtual space through a truncated pair natural orbital (PNO) basis. In this paper, we report on the implementation of an analytic scheme for the calculation of the first derivatives of the DLPNO-CC energy for basis set independent perturbations within the singles and doubles approximation (DLPNO-CCSD) for closed-shell molecules. Perturbation-independent one-particle density matrices have been implemented in order to account for the response of the CC wave function to the external perturbation. Orbital-relaxation effects due to external perturbation are not taken into account in the current implementation. We investigate in detail the dependence of the computed first-order electrical properties (e.g., dipole moment) on the three major truncation parameters used in a DLPNO-CC calculation, namely, the natural orbital occupation number cutoff used for the construction of the PNOs, the weak electron-pair cutoff, and the domain size cutoff. No additional truncation parameter has been introduced for property calculation. We present benchmark calculations on dipole moments for a set of 10 molecules consisting of 20-40 atoms. We demonstrate that 98%-99% accuracy relative to the canonical CCSD results can be consistently achieved in these calculations. However, this comes with the price of tightening the

  13. The evaluation of enhanced feedback interventions to reduce unnecessary blood transfusions (AFFINITIE): protocol for two linked cluster randomised factorial controlled trials.

    Science.gov (United States)

    Hartley, Suzanne; Foy, Robbie; Walwyn, Rebecca E A; Cicero, Robert; Farrin, Amanda J; Francis, Jill J; Lorencatto, Fabiana; Gould, Natalie J; Grant-Casey, John; Grimshaw, Jeremy M; Glidewell, Liz; Michie, Susan; Morris, Stephen; Stanworth, Simon J

    2017-07-03

    Blood for transfusion is a frequently used clinical intervention, and is also a costly and limited resource with risks. Many transfusions are given to stable and non-bleeding patients despite no clear evidence of benefit from clinical studies. Audit and feedback (A&F) is widely used to improve the quality of healthcare, including appropriate use of blood. However, its effects are often inconsistent, indicating the need for coordinated research including more head-to-head trials comparing different ways of delivering feedback. A programmatic series of research projects, termed the 'Audit and Feedback INterventions to Increase evidence-based Transfusion practIcE' (AFFINITIE) programme, aims to test different ways of developing and delivering feedback within an existing national audit structure. The evaluation will comprise two linked 2×2 factorial, cross-sectional cluster-randomised controlled trials. Each trial will estimate the effects of two feedback interventions, 'enhanced content' and 'enhanced follow-on support', designed in earlier stages of the AFFINITIE programme, compared to current practice. The interventions will be embedded within two rounds of the UK National Comparative Audit of Blood Transfusion (NCABT) focusing on patient blood management in surgery and use of blood transfusions in patients with haematological malignancies. The unit of randomisation will be National Health Service (NHS) trust or health board. Clusters providing care relevant to the audit topics will be randomised following each baseline audit (separately for each trial), with stratification for size (volume of blood transfusions) and region (Regional Transfusion Committee). The primary outcome for each topic will be the proportion of patients receiving a transfusion coded as unnecessary. For each audit topic a linked, mixed-method fidelity assessment and cost-effectiveness analysis will be conducted in parallel to the trial. AFFINITIE involves a series of studies to explore how A

  14. Enhancing Recruitment Using Teleconference and Commitment Contract (ERUTECC): study protocol for a randomised, stepped-wedge cluster trial within the EFFECTS trial.

    Science.gov (United States)

    Lundström, Erik; Isaksson, Eva; Wester, Per; Laska, Ann-Charlotte; Näsman, Per

    2018-01-08

    Many randomised controlled trials (RCTs) fail to meet their recruitment goals in time. Trialists are advised to include study recruitment strategies within their trials. EFFECTS is a Swedish, academic-led RCT of fluoxetine for stroke recovery. The trial's primary objective is to investigate whether 20 mg fluoxetine daily compared with placebo for 6 months after an acute stroke improves the patient's functional outcome. The first patient was included on 20 October 2014 and, as of 31 August 2017, EFFECTS has included 810 of planned 1500 individuals. EFFECTS currently has 32 active centres. The primary objective of the ERUTECC (Enhancing Recruitment Using Teleconference and Commitment Contract) study is to investigate whether a structured teleconference re-visit with the study personnel at the centres, accompanied by a commitment contract, can enhance recruitment by 20% at 60 days post intervention, compared with 60 days pre-intervention, in an ongoing RCT. ERUTECC is a randomised, stepped-wedge cluster trial embedded in EFFECTS. The plan is to start ERUTECC with a running-in period of September 2017. The first intervention is due in October 2017, and the study will continue for 12 months. We are planning to intervene at all active centres in EFFECTS, except the five top recruiting centres (n = 27). The rationale for not intervening at the top recruiting centres is that we believe they have reached their full potential and the intervention would be too weak for them. The hypothesis of this study is that a structured teleconference re-visit with the study personnel at the centres, accompanied by a commitment contract, can enhance recruitment by 20% 60 days post intervention, compared to 60 days pre-intervention, in an ongoing RCT. EFFECTS is a large, pragmatic RCT of stroke in Sweden. Results from the embedded ERUTECC study could probably be generalised to high-income Western countries, and is relevant to trial management and could improve trial management in the

  15. Can Single-Reference Coupled Cluster Theory Describe Static Correlation?

    Science.gov (United States)

    Bulik, Ireneusz W; Henderson, Thomas M; Scuseria, Gustavo E

    2015-07-14

    While restricted single-reference coupled cluster theory truncated to singles and doubles (CCSD) provides very accurate results for weakly correlated systems, it usually fails in the presence of static or strong correlation. This failure is generally attributed to the qualitative breakdown of the reference, and can accordingly be corrected by using a multideterminant reference, including higher-body cluster operators in the ansatz, or allowing symmetry breaking in the reference. None of these solutions are ideal; multireference coupled cluster is not black box, including higher-body cluster operators is computationally demanding, and allowing symmetry breaking leads to the loss of good quantum numbers. It has long been recognized that quasidegeneracies can instead be treated by modifying the coupled cluster ansatz. The recently introduced pair coupled cluster doubles (pCCD) approach is one such example which avoids catastrophic failures and accurately models strong correlations in a symmetry-adapted framework. Here, we generalize pCCD to a singlet-paired coupled cluster model (CCD0) intermediate between coupled cluster doubles and pCCD, yielding a method that possesses the invariances of the former and much of the stability of the latter. Moreover, CCD0 retains the full structure of coupled cluster theory, including a fermionic wave function, antisymmetric cluster amplitudes, and well-defined response equations and density matrices.

  16. How to detect trap cluster systems?

    International Nuclear Information System (INIS)

    Mandowski, Arkadiusz

    2008-01-01

    Spatially correlated traps and recombination centres (trap-recombination centre pairs and larger clusters) are responsible for many anomalous phenomena that are difficult to explain in the framework of both classical models, i.e. model of localized transitions (LT) and the simple trap model (STM), even with a number of discrete energy levels. However, these 'anomalous' effects may provide a good platform for identifying trap cluster systems. This paper considers selected cluster-type effects, mainly relating to an anomalous dependence of TL on absorbed dose in the system of isolated clusters (ICs). Some consequences for interacting cluster (IAC) systems, involving both localized and delocalized transitions occurring simultaneously, are also discussed

  17. Evaluating a community-based early childhood education and development program in Indonesia: study protocol for a pragmatic cluster randomized controlled trial with supplementary matched control group

    NARCIS (Netherlands)

    Pradhan, M.; Brinkman, S.A.; Beatty, A.; Maika, A.; Satriawan, E.; de Ree, J.; Hasan, A.

    2013-01-01

    Background This paper presents the study protocol for a pragmatic cluster randomized controlled trial (RCT) with a supplementary matched control group. The aim of the trial is to evaluate a community-based early education and development program launched by the Government of Indonesia. The program

  18. Evaluating a community-based early childhood education and development program in Indonesia: study protocol for a pragmatic cluster randomized controlled trial with supplementary matched control group

    NARCIS (Netherlands)

    Pradhan, M.P.; Brinkman, S.A.; Beatty, A.; Maika, A.; Satriawan, E.; de Ree, J.; Hasan, A.

    2013-01-01

    Background: This paper presents the study protocol for a pragmatic cluster randomized controlled trial (RCT) with a supplementary matched control group. The aim of the trial is to evaluate a community-based early education and development program launched by the Government of Indonesia. The program

  19. Effectiveness of single dose rifampicin in preventing leprosy in close contacts of patients with newly diagnosed leprosy: cluster randomised controlled trial

    NARCIS (Netherlands)

    Moet, F. Johannes; Pahan, David; Oskam, Linda; Richardus, Jan H.; van Brakel, Wim H.; Klatser, Paul R.; Saunderson, Paul R.; Smith, W. Cairns S.; Withington, Steve G.; Richardus, Jan Hendrik; Schuring, Ron P.; Faber, Roel; Borsboom, Gerard J. J. M.

    2008-01-01

    OBJECTIVE: To determine the effectiveness of chemoprophylaxis using a single dose of rifampicin to prevent leprosy in close contacts. DESIGN: Single centre, double blind, cluster randomised, placebo controlled trial. SETTING: Leprosy control programme in two districts of northwest Bangladesh with a

  20. Pearson's chi-square test and rank correlation inferences for clustered data.

    Science.gov (United States)

    Shih, Joanna H; Fay, Michael P

    2017-09-01

    Pearson's chi-square test has been widely used in testing for association between two categorical responses. Spearman rank correlation and Kendall's tau are often used for measuring and testing association between two continuous or ordered categorical responses. However, the established statistical properties of these tests are only valid when each pair of responses are independent, where each sampling unit has only one pair of responses. When each sampling unit consists of a cluster of paired responses, the assumption of independent pairs is violated. In this article, we apply the within-cluster resampling technique to U-statistics to form new tests and rank-based correlation estimators for possibly tied clustered data. We develop large sample properties of the new proposed tests and estimators and evaluate their performance by simulations. The proposed methods are applied to a data set collected from a PET/CT imaging study for illustration. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  1. The AWED trial (Applying Wolbachia to Eliminate Dengue) to assess the efficacy of Wolbachia-infected mosquito deployments to reduce dengue incidence in Yogyakarta, Indonesia: study protocol for a cluster randomised controlled trial.

    Science.gov (United States)

    Anders, Katherine L; Indriani, Citra; Ahmad, Riris Andono; Tantowijoyo, Warsito; Arguni, Eggi; Andari, Bekti; Jewell, Nicholas P; Rances, Edwige; O'Neill, Scott L; Simmons, Cameron P; Utarini, Adi

    2018-05-31

    Dengue and other arboviruses transmitted by Aedes aegypti mosquitoes, including Zika and chikungunya, present an increasing public health challenge in tropical regions. Current vector control strategies have failed to curb disease transmission, but continue to be employed despite the absence of robust evidence for their effectiveness or optimal implementation. The World Mosquito Program has developed a novel approach to arbovirus control using Ae. aegypti stably transfected with Wolbachia bacterium, with a significantly reduced ability to transmit dengue, Zika and chikungunya in laboratory experiments. Modelling predicts this will translate to local elimination of dengue in most epidemiological settings. This study protocol describes the first trial to measure the efficacy of Wolbachia in reducing dengue virus transmission in the field. The study is a parallel, two-arm, non-blinded cluster randomised controlled trial conducted in a single site in Yogyakarta, Indonesia. The aim is to determine whether large-scale deployment of Wolbachia-infected Ae. aegypti mosquitoes leads to a measurable reduction in dengue incidence in treated versus untreated areas. The primary endpoint is symptomatic, virologically confirmed dengue virus infection of any severity. The 26 km 2 study area was subdivided into 24 contiguous clusters, allocated randomly 1:1 to receive Wolbachia deployments or no intervention. We use a novel epidemiological study design, the cluster-randomised test-negative design trial, in which dengue cases and arbovirus-negative controls are sampled concurrently from among febrile patients presenting to a network of primary care clinics, with case or control status classified retrospectively based on the results of laboratory diagnostic testing. Efficacy is estimated from the odds ratio of Wolbachia exposure distribution (probability of living in a Wolbachia-treated area) among virologically confirmed dengue cases compared to test-negative controls. A secondary

  2. Effect of a Nutrition Supplement and Physical Activity Program on Pneumonia and Walking Capacity in Chilean Older People: A Factorial Cluster Randomized Trial

    Science.gov (United States)

    Dangour, Alan D.; Albala, Cecilia; Allen, Elizabeth; Grundy, Emily; Walker, Damian G.; Aedo, Cristian; Sanchez, Hugo; Fletcher, Olivia; Elbourne, Diana; Uauy, Ricardo

    2011-01-01

    Background Ageing is associated with increased risk of poor health and functional decline. Uncertainties about the health-related benefits of nutrition and physical activity for older people have precluded their widespread implementation. We investigated the effectiveness and cost-effectiveness of a national nutritional supplementation program and/or a physical activity intervention among older people in Chile. Methods and Findings We conducted a cluster randomized factorial trial among low to middle socioeconomic status adults aged 65–67.9 years living in Santiago, Chile. We randomized 28 clusters (health centers) into the study and recruited 2,799 individuals in 2005 (∼100 per cluster). The interventions were a daily micronutrient-rich nutritional supplement, or two 1-hour physical activity classes per week, or both interventions, or neither, for 24 months. The primary outcomes, assessed blind to allocation, were incidence of pneumonia over 24 months, and physical function assessed by walking capacity 24 months after enrolment. Adherence was good for the nutritional supplement (∼75%), and moderate for the physical activity intervention (∼43%). Over 24 months the incidence rate of pneumonia did not differ between intervention and control clusters (32.5 versus 32.6 per 1,000 person years respectively; risk ratio = 1.00; 95% confidence interval 0.61–1.63; p = 0.99). In intention-to-treat analysis, after 24 months there was a significant difference in walking capacity between the intervention and control clusters (mean difference 33.8 meters; 95% confidence interval 13.9–53.8; p = 0.001). The overall cost of the physical activity intervention over 24 months was US$164/participant; equivalent to US$4.84/extra meter walked. The number of falls and fractures was balanced across physical activity intervention arms and no serious adverse events were reported for either intervention. Conclusions Chile's nutritional supplementation program for older

  3. Improvement of perinatal and newborn care in rural Pakistan through community-based strategies: a cluster-randomised effectiveness trial.

    Science.gov (United States)

    Bhutta, Zulfiqar A; Soofi, Sajid; Cousens, Simon; Mohammad, Shah; Memon, Zahid A; Ali, Imran; Feroze, Asher; Raza, Farrukh; Khan, Amanullah; Wall, Steve; Martines, Jose

    2011-01-29

    Newborn deaths account for 57% of deaths in children younger than 5 years in Pakistan. Although a large programme of trained lady health workers (LHWs) exists, the effectiveness of this training on newborn outcomes has not been studied. We aimed to evaluate the effectiveness of a community-based intervention package, principally delivered through LHWs working with traditional birth attendants and community health committees, for reduction of perinatal and neonatal mortality in a rural district of Pakistan. We undertook a cluster randomised trial between February, 2006, and March, 2008, in Hala and Matiari subdistricts, Pakistan. Catchment areas of primary care facilities and all affiliated LHWs were used to define clusters, which were allocated to intervention and control groups by restricted, stratified randomisation. The intervention package delivered by LHWs through group sessions consisted of promotion of antenatal care and maternal health education, use of clean delivery kits, facility births, immediate newborn care, identification of danger signs, and promotion of careseeking; control clusters received routine care. Independent data collectors undertook quarterly household surveillance to capture data for births, deaths, and household practices related to maternal and newborn care. Data collectors were masked to cluster allocation; those analysing data were not. The primary outcome was perinatal and all-cause neonatal mortality. Analysis was by intention to treat. This trial is registered, ISRCTN16247511. 16 clusters were assigned to intervention (23,353 households, 12,391 total births) and control groups (23,768 households, 11,443 total births). LHWs in the intervention clusters were able to undertake 4428 (63%) of 7084 planned group sessions, but were only able to visit 2943 neonates (24%) of a total 12,028 livebirths in their catchment villages. Stillbirths were reduced in intervention clusters (39·1 stillbirths per 1000 total births) compared with

  4. Effect of Behavior Modification on Outcome in Early- to Moderate-Stage Chronic Kidney Disease: A Cluster-Randomized Trial.

    Science.gov (United States)

    Yamagata, Kunihiro; Makino, Hirofumi; Iseki, Kunitoshi; Ito, Sadayoshi; Kimura, Kenjiro; Kusano, Eiji; Shibata, Takanori; Tomita, Kimio; Narita, Ichiei; Nishino, Tomoya; Fujigaki, Yoshihide; Mitarai, Tetsuya; Watanabe, Tsuyoshi; Wada, Takashi; Nakamura, Teiji; Matsuo, Seiichi

    2016-01-01

    Owing to recent changes in our understanding of the underlying cause of chronic kidney disease (CKD), the importance of lifestyle modification for preventing the progression of kidney dysfunction and complications has become obvious. In addition, effective cooperation between general physicians (GPs) and nephrologists is essential to ensure a better care system for CKD treatment. In this cluster-randomized study, we studied the effect of behavior modification on the outcome of early- to moderate-stage CKD. Stratified open cluster-randomized trial. A total of 489 GPs belonging to 49 local medical associations (clusters) in Japan. A total of 2,379 patients (1,195 in group A (standard intervention) and 1,184 in group B (advanced intervention)) aged between 40 and 74 years, who had CKD and were under consultation with GPs. All patients were managed in accordance with the current CKD guidelines. The group B clusters received three additional interventions: patients received both educational intervention for lifestyle modification and a CKD status letter, attempting to prevent their withdrawal from treatment, and the group B GPs received data sheets to facilitate reducing the gap between target and practice. The primary outcome measures were 1) the non-adherence rate of accepting continuous medical follow-up of the patients, 2) the collaboration rate between GPs and nephrologists, and 3) the progression of CKD. The rate of discontinuous clinical visits was significantly lower in group B (16.2% in group A vs. 11.5% in group B, p = 0.01). Significantly higher referral and co-treatment rates were observed in group B (pbehavior modification of CKD patients, namely, significantly lower discontinuous clinical visits, and behavior modification of both GPs and nephrologists, namely significantly higher referral and co-treatment rates, resulting in the retardation of CKD progression, especially in patients with proteinuric Stage 3 CKD. The University Hospital Medical Information

  5. A Cluster-Randomized Trial of Restorative Practices: An Illustration to Spur High-Quality Research and Evaluation.

    Science.gov (United States)

    Acosta, Joie D; Chinman, Matthew; Ebener, Patricia; Phillips, Andrea; Xenakis, Lea; Malone, Patrick S

    2016-01-01

    Restorative Practices in schools lack rigorous evaluation studies. As an example of rigorous school-based research, this paper describes the first randomized control trial of restorative practices to date, the Study of Restorative Practices. It is a 5-year, cluster-randomized controlled trial (RCT) of the Restorative Practices Intervention (RPI) in 14 middle schools in Maine to assess whether RPI impacts both positive developmental outcomes and problem behaviors and whether the effects persist during the transition from middle to high school. The two-year RPI intervention began in the 2014-2015 school year. The study's rationale and theoretical concerns are discussed along with methodological concerns including teacher professional development. The theoretical rationale and description of the methods from this study may be useful to others conducting rigorous research and evaluation in this area.

  6. A Cluster Randomised Trial Introducing Rapid Diagnostic Tests into Registered Drug Shops in Uganda: Impact on Appropriate Treatment of Malaria

    Science.gov (United States)

    Mbonye, Anthony K.; Magnussen, Pascal; Lal, Sham; Hansen, Kristian S.; Cundill, Bonnie; Chandler, Clare; Clarke, Siân E.

    2015-01-01

    Background Inappropriate treatment of malaria is widely reported particularly in areas where there is poor access to health facilities and self-treatment of fevers with anti-malarial drugs bought in shops is the most common form of care-seeking. The main objective of the study was to examine the impact of introducing rapid diagnostic tests for malaria (mRDTs) in registered drug shops in Uganda, with the aim to increase appropriate treatment of malaria with artemisinin-based combination therapy (ACT) in patients seeking treatment for fever in drug shops. Methods A cluster-randomized trial of introducing mRDTs in registered drug shops was implemented in 20 geographical clusters of drug shops in Mukono district, central Uganda. Ten clusters were randomly allocated to the intervention (diagnostic confirmation of malaria by mRDT followed by ACT) and ten clusters to the control arm (presumptive treatment of fevers with ACT). Treatment decisions by providers were validated by microscopy on a reference blood slide collected at the time of consultation. The primary outcome was the proportion of febrile patients receiving appropriate treatment with ACT defined as: malaria patients with microscopically-confirmed presence of parasites in a peripheral blood smear receiving ACT or rectal artesunate, and patients with no malaria parasites not given ACT. Findings A total of 15,517 eligible patients (8672 intervention and 6845 control) received treatment for fever between January-December 2011. The proportion of febrile patients who received appropriate ACT treatment was 72·9% versus 33·7% in the control arm; a difference of 36·1% (95% CI: 21·3 – 50·9), pshop vendors adhered to the mRDT results, reducing over-treatment of malaria by 72·6% (95% CI: 46·7– 98·4), pshop vendors using presumptive diagnosis (control arm). Conclusion Diagnostic testing with mRDTs compared to presumptive treatment of fevers implemented in registered drug shops substantially improved appropriate

  7. Effect on postpartum hemorrhage of prophylactic oxytocin (10 IU by injection by community health officers in Ghana: a community-based, cluster-randomized trial.

    Directory of Open Access Journals (Sweden)

    Cynthia K Stanton

    2013-10-01

    Full Text Available BACKGROUND: Oxytocin (10 IU is the drug of choice for prevention of postpartum hemorrhage (PPH. Its use has generally been restricted to medically trained staff in health facilities. We assessed the effectiveness, safety, and feasibility of PPH prevention using oxytocin injected by peripheral health care providers without midwifery skills at home births. METHODS AND FINDINGS: This community-based, cluster-randomized trial was conducted in four rural districts in Ghana. We randomly allocated 54 community health officers (stratified on district and catchment area distance to a health facility: ≥10 km versus <10 km to intervention (one injection of oxytocin [10 IU] one minute after birth and control (no provision of prophylactic oxytocin arms. Births attended by a community health officer constituted a cluster. Our primary outcome was PPH, using multiple definitions; (PPH-1 blood loss ≥500 mL; (PPH-2 PPH-1 plus women who received early treatment for PPH; and (PPH-3 PPH-2 plus any other women referred to hospital for postpartum bleeding. Unsafe practice is defined as oxytocin use before delivery of the baby. We enrolled 689 and 897 women, respectively, into oxytocin and control arms of the trial from April 2011 to November 2012. In oxytocin and control arms, respectively, PPH-1 rates were 2.6% versus 5.5% (RR: 0.49; 95% CI: 0.27-0.88; PPH-2 rates were 3.8% versus 10.8% (RR: 0.35; 95% CI: 0.18-0.63, and PPH-3 rates were similar to those of PPH-2. Compared to women in control clusters, those in the intervention clusters lost 45.1 mL (17.7-72.6 less blood. There were no cases of oxytocin use before delivery of the baby and no major adverse events requiring notification of the institutional review boards. Limitations include an unblinded trial and imbalanced numbers of participants, favoring controls. CONCLUSION: Maternal health care planners can consider adapting this model to extend the use of oxytocin into peripheral settings including, in some

  8. The effectiveness of a clinically integrated e-learning course in evidence-based medicine: A cluster randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Arvanitis Theodoros N

    2009-05-01

    Full Text Available Abstract Background To evaluate the educational effects of a clinically integrated e-learning course for teaching basic evidence-based medicine (EBM among postgraduates compared to a traditional lecture-based course of equivalent content. Methods We conducted a cluster randomised controlled trial in the Netherlands and the UK involving postgraduate trainees in six obstetrics and gynaecology departments. Outcomes (knowledge gain and change in attitude towards EBM were compared between the clinically integrated e-learning course (intervention and the traditional lecture based course (control. We measured change from pre- to post-intervention scores using a validated questionnaire assessing knowledge (primary outcome and attitudes (secondary outcome. Results There were six clusters involving teaching of 61 postgraduate trainees (28 in the intervention and 33 in the control group. The intervention group achieved slightly higher scores for knowledge gain compared to the control, but these results were not statistically significant (difference in knowledge gain: 3.5 points, 95% CI -2.7 to 9.8, p = 0.27. The attitudinal changes were similar for both groups. Conclusion A clinically integrated e-learning course was at least as effective as a traditional lecture based course and was well accepted. Being less costly than traditional teaching and allowing for more independent learning through materials that can be easily updated, there is a place for incorporating e-learning into postgraduate EBM curricula that offer on-the-job training for just-in-time learning. Trial registration Trial registration number: ACTRN12609000022268.

  9. The Infant Feeding Activity and Nutrition Trial (INFANT an early intervention to prevent childhood obesity: Cluster-randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Campbell Karen

    2008-03-01

    Full Text Available Abstract Background Multiple factors combine to support a compelling case for interventions that target the development of obesity-promoting behaviours (poor diet, low physical activity and high sedentary behaviour from their inception. These factors include the rapidly increasing prevalence of fatness throughout childhood, the instigation of obesity-promoting behaviours in infancy, and the tracking of these behaviours from childhood through to adolescence and adulthood. The Infant Feeding Activity and Nutrition Trial (INFANT aims to determine the effectiveness of an early childhood obesity prevention intervention delivered to first-time parents. The intervention, conducted with parents over the infant's first 18 months of life, will use existing social networks (first-time parent's groups and an anticipatory guidance framework focusing on parenting skills which support the development of positive diet and physical activity behaviours, and reduced sedentary behaviours in infancy. Methods/Design This cluster-randomised controlled trial, with first-time parent groups as the unit of randomisation, will be conducted with a sample of 600 first-time parents and their newborn children who attend the first-time parents' group at Maternal and Child Health Centres. Using a two-stage sampling process, local government areas in Victoria, Australia will be randomly selected at the first stage. At the second stage, a proportional sample of first-time parent groups within selected local government areas will be randomly selected and invited to participate. Informed consent will be obtained and groups will then be randomly allocated to the intervention or control group. Discussion The early years hold promise as a time in which obesity prevention may be most effective. To our knowledge this will be the first randomised trial internationally to demonstrate whether an early health promotion program delivered to first-time parents in their existing social groups

  10. Effectiveness of a smartphone app on improving immunization of children in rural Sichuan Province, China: a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Li Chen

    2016-08-01

    Full Text Available Abstract Background The aim of this study was to assess the effectiveness of an EPI smartphone application (EPI app on improving vaccination coverage in rural Sichuan Province, China. Methods This matched-pair cluster randomized controlled study included 32 village doctors, matched in 16 pairs, and took place from 2013 to 2015. Village doctors in the intervention group used the EPI app and reminder text messages while village doctors in the control group used their usual procedures and text messages. The primary outcome was full vaccination coverage with all five vaccines (1 dose of BCG, 3 doses of hepatitis B, 3 doses of OPV, 3 doses of DPT and 1 dose of measles vaccine, and the secondary outcome was coverage with each dose of the five individual vaccines. We also conducted qualitative interviews with village doctors to understand perceptions on using the EPI app and how this changed their vaccination work. Results The full vaccination coverage increased statistically significant from baseline to end-line in both the intervention (67 % [95 % CI:58-75 %] to 84 % [95 % CI:76-90 %], P = 0.028 and control group (71 % [95 % CI:62-79 %] to 82 % [95 % CI:74-88 %], P = 0.014. The intervention group had higher increase in full vaccination coverage from baseline to end-line compared to the control group (17 % vs 10 %, but this was not statistically significant (P = 0.164. Village doctors found it more convenient to use the EPI app to manage child vaccination and also reported saving time by looking up information of caregivers and contacting caregivers for overdue vaccinations quicker. However, village doctors found it hard to manage children who migrated out of the counties. Conclusions This study showed that an app and text messages can be used by village doctors to improve full vaccination coverage, though no significant increase in vaccination coverage was found when assessing the effect of the app on its own. Village

  11. COSMOS--improving the quality of life in nursing home patients: protocol for an effectiveness-implementation cluster randomized clinical hybrid trial.

    Science.gov (United States)

    Husebo, Bettina S; Flo, Elisabeth; Aarsland, Dag; Selbaek, Geir; Testad, Ingelin; Gulla, Christine; Aasmul, Irene; Ballard, Clive

    2015-09-15

    Nursing home patients have complex mental and physical health problems, disabilities and social needs, combined with widespread prescription of psychotropic drugs. Preservation of their quality of life is an important goal. This can only be achieved within nursing homes that offer competent clinical conditions of treatment and care. COmmunication, Systematic assessment and treatment of pain, Medication review, Occupational therapy, Safety (COSMOS) is an effectiveness-implementation hybrid trial that combines and implements organization of activities evidence-based interventions to improve staff competence and thereby the patients' quality of life, mental health and safety. The aim of this paper is to describe the development, content and implementation process of the COSMOS trial. COSMOS includes a 2-month pilot study with 128 participants distributed among nine Norwegian nursing homes, and a 4-month multicenter, cluster randomized effectiveness-implementation clinical hybrid trial with follow-up at month 9, including 571 patients from 67 nursing home units (one unit defined as one cluster). Clusters are randomized to COSMOS intervention or current best practice (control group). The intervention group will receive a 2-day education program including written guidelines, repeated theoretical and practical training (credited education of caregivers, physicians and nursing home managers), case discussions and role play. The 1-day midway evaluation, information and interviews of nursing staff and a telephone hotline all support the implementation process. Outcome measures include quality of life in late-stage dementia, neuropsychiatric symptoms, activities of daily living, pain, depression, sleep, medication, cost-utility analysis, hospital admission and mortality. Despite complex medical and psychosocial challenges, nursing home patients are often treated by staff possessing low level skills, lacking education and in facilities with a high staff turnover

  12. Snoezelen, structured reminiscence therapy and 10-minutes activation in long term care residents with dementia (WISDE: study protocol of a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Becker Christiane

    2010-01-01

    Full Text Available Abstract Background People with dementia are often inapproachable due to symptoms of their illness. Therefore nurses should establish relationships with dementia patients via their remaining resources and facilitate communication. In order to achieve this, different targeted non-pharmacological interventions are recommended and practiced. However there is no sufficient evidence about the efficacy of most of these interventions. A number of publications highlight the urgent need for methodological sound studies so that more robust conclusions may be drawn. Methods/Design The trial is designed as a cluster randomized controlled trial with 20 nursing homes in Saxony and Saxony-Anhalt (Germany as the units of randomization. Nursing homes will be randomly allocated into 4 study groups consisting of 5 clusters and 90 residents: snoezelen, structured reminiscence therapy, 10-minutes activation or unstructured verbal communication (control group. The purpose is to determine whether the interventions are effective to reduce apathy in long-term care residents with dementia (N = 360 as the main outcome measure. Assessments will be done at baseline, 3, 6 and 12 months after beginning of the interventions. Discussion This trial will particularly contribute to the evidence on efficacy of non-pharmacological interventions in dementia care. Trial Registration ClinicalTrials.gov NCT00653731

  13. Mapping world cultures: Cluster formation, sources and implications

    OpenAIRE

    Simcha Ronen; Oded Shenkar

    2013-01-01

    This paper extends and builds on Ronen and Shenkar’s synthesized cultural clustering of countries based on similarity and dissimilarity in work-related attitudes. The new map uses an updated dataset, and expands coverage to world areas that were non-accessible at the time. Cluster boundaries are drawn empirically rather than intuitively, and the plot obtained is triple nested, indicating three levels of similarity across given country pairs. Also delineated are cluster adjacency and cluster c...

  14. Spectroscopy of metal "superatom" nanoclusters and high-Tc superconducting pairing

    Science.gov (United States)

    Halder, Avik; Kresin, Vitaly V.

    2015-12-01

    A unique property of metal nanoclusters is the "superatom" shell structure of their delocalized electrons. The electronic shell levels are highly degenerate and therefore represent sharp peaks in the density of states. This can enable exceptionally strong electron pairing in certain clusters composed of tens to hundreds of atoms. In a finite system, such as a free nanocluster or a nucleus, pairing is observed most clearly via its effect on the energy spectrum of the constituent fermions. Accordingly, we performed a photoionization spectroscopy study of size-resolved aluminum nanoclusters and observed a rapid rise in the near-threshold density of states of several clusters (A l37 ,44 ,66 ,68 ) with decreasing temperature. The characteristics of this behavior are consistent with compression of the density of states by a pairing transition into a high-temperature superconducting state with Tc≳100 K. This value exceeds that of bulk aluminum by two orders of magnitude. These results highlight the potential of novel pairing effects in size-quantized systems and the possibility to attain even higher critical temperatures by optimizing the particles' size and composition. As a new class of high-temperature superconductors, such metal nanocluster particles are promising building blocks for high-Tc materials, devices, and networks.

  15. Efficacy of a workplace osteoporosis prevention intervention: a cluster randomized trial

    Directory of Open Access Journals (Sweden)

    Ai May Tan

    2016-08-01

    Full Text Available Abstract Background Osteoporosis is a debilitating disease. Adequate calcium consumption and physical activity are the two major modifiable risk factors. This paper describes the major outcomes and efficacy of a workplace-based targeted behaviour change intervention to improve the dietary and physical activity behaviours of working women in sedentary occupations in Singapore. Methods A cluster-randomized design was used, comparing the efficacy of a tailored intervention to standard care. Workplaces were the units of randomization and intervention. Sixteen workplaces were recruited from a pool of 97, and randomly assigned to intervention and control arms (eight workplaces in each. Women meeting specified inclusion criteria were then recruited to participate. Workplaces in the intervention arm received three participatory workshops and organization-wide educational activities. Workplaces in the control/standard care arm received print resources. Outcome measures were calcium intake (milligrams/day and physical activity level (duration: minutes/week, measured at baseline, 4 weeks and 6 months post intervention. Adjusted cluster-level analyses were conducted comparing changes in intervention versus control groups, following intention-to-treat principles and CONSORT guidelines. Results Workplaces in the intervention group reported a significantly greater increase in calcium intake and duration of load-bearing moderate to vigorous physical activity (MVPA compared with the standard care control group. Four weeks after intervention, the difference in adjusted mean calcium intake was 343.2 mg/day (95 % CI = 337.4 to 349.0, p < .0005 and the difference in adjusted mean load-bearing MVPA was 55.6 min/week (95 % CI = 54.5 to 56.6, p < .0005. Six months post intervention, the mean differences attenuated slightly to 290.5 mg/day (95 % CI = 285.3 to 295.7, p < .0005 and 50.9 min/week (95 % CI =49.3 to 52.6, p < .0005

  16. Long term effectiveness on prescribing of two multifaceted educational interventions: results of two large scale randomized cluster trials.

    Directory of Open Access Journals (Sweden)

    Nicola Magrini

    Full Text Available INTRODUCTION: Information on benefits and risks of drugs is a key element affecting doctors' prescribing decisions. Outreach visits promoting independent information have proved moderately effective in changing prescribing behaviours. OBJECTIVES: Testing the short and long-term effectiveness on general practitioners' prescribing of small groups meetings led by pharmacists. METHODS: Two cluster open randomised controlled trials (RCTs were carried out in a large scale NHS setting. Ad hoc prepared evidence based material were used considering a therapeutic area approach--TEA, with information materials on osteoporosis or prostatic hyperplasia--and a single drug oriented approach--SIDRO, with information materials on me-too drugs of 2 different classes: barnidipine or prulifloxacin. In each study, all 115 Primary Care Groups in a Northern Italy area (2.2 million inhabitants, 1737 general practitioners were randomised to educational small groups meetings, in which available evidence was provided together with drug utilization data and clinical scenarios. Main outcomes were changes in the six-months prescription of targeted drugs. Longer term results (24 and 48 months were also evaluated. RESULTS: In the TEA trial, one of the four primary outcomes showed a reduction (prescription of alfuzosin compared to tamsulosin and terazosin in benign prostatic hyperplasia: prescribing ratio -8.5%, p = 0.03. Another primary outcome (prescription of risedronate showed a reduction at 24 and 48 months (-7.6%, p = 0.02; and -9,8%, p = 0.03, but not at six months (-5.1%, p = 0.36. In the SIDRO trial both primary outcomes showed a statistically significant reduction (prescription of barnidipine -9.8%, p = 0.02; prescription of prulifloxacin -11.1%, p = 0.04, which persisted or increased over time. INTERPRETATION: These two cluster RCTs showed the large scale feasibility of a complex educational program in a NHS setting, and its potentially

  17. Effect of Reassuring Information About Musculoskeletal and Mental Health Complaints at the Workplace: A Cluster Randomized Trial of the atWork Intervention.

    Science.gov (United States)

    Johnsen, Tone Langjordet; Eriksen, Hege Randi; Baste, Valborg; Indahl, Aage; Odeen, Magnus; Tveito, Torill Helene

    2018-05-21

    Purpose The purpose of this study was to investigate the possible difference between the Modified atWork intervention (MAW) and the Original atWork intervention (OAW) on sick leave and other health related outcomes. atWork is a group intervention using the workplace as an arena for distribution of evidence-based knowledge about musculoskeletal and mental health complaints. Methods A cluster randomized controlled trial with 93 kindergartens, comprising a total of 1011 employees, was conducted. Kindergartens were stratified by county and size and randomly allocated to MAW (45 clusters, 324 respondents) or OAW (48 clusters, 313 respondents). The randomization and intervention allocation processes were concealed. There was no blinding to group allocation. Primary outcome was register data on sick leave at cluster level. Secondary outcomes were health complaints, job satisfaction, social support, coping, and beliefs about musculoskeletal and mental health complaints, measured at the individual level. Results The MAW group reduced sick leave by 5.7% during the intervention year, while the OAW group had a 7.5% increase. Overall, the changes were not statistically significant, and no difference was detected between groups, based on 45 and 47 kindergartens. Compared to the OAW group, the MAW group had a smaller reduction for two of the statements concerning faulty beliefs about back pain, but believed less in the hereditary nature of depression. Conclusions The MAW did not have a different effect on sick leave at cluster level compared to the OAW. Trial registration https://Clinicaltrials.gov/ : NCT02396797. Registered March 23th, 2015.

  18. The Potts model and flows. 1. The pair correlation function

    International Nuclear Information System (INIS)

    Essam, J.W.; Tsallis, C.

    1985-01-01

    It is shown that the partition function for the lambda-state Potts model with pair-interactions is related to the expected number of integer mod-lambda flows in a percolation model. The relation is generalised to the pair correlation function. The resulting high temperature expansion coefficients are shown to be the flow polynomials of graph theory. An observation of Tsallis and Levy concerning the equivalent transmissivity of a cluster is also proved. (Author) [pt

  19. Double-partition Quantum Cluster Algebras

    DEFF Research Database (Denmark)

    Jakobsen, Hans Plesner; Zhang, Hechun

    2012-01-01

    A family of quantum cluster algebras is introduced and studied. In general, these algebras are new, but sub-classes have been studied previously by other authors. The algebras are indexed by double parti- tions or double flag varieties. Equivalently, they are indexed by broken lines L. By grouping...... together neighboring mutations into quantum line mutations we can mutate from the cluster algebra of one broken line to another. Compatible pairs can be written down. The algebras are equal to their upper cluster algebras. The variables of the quantum seeds are given by elements of the dual canonical basis....

  20. Multiscale synchrony behaviors of paired financial time series by 3D multi-continuum percolation

    Science.gov (United States)

    Wang, M.; Wang, J.; Wang, B. T.

    2018-02-01

    Multiscale synchrony behaviors and nonlinear dynamics of paired financial time series are investigated, in an attempt to study the cross correlation relationships between two stock markets. A random stock price model is developed by a new system called three-dimensional (3D) multi-continuum percolation system, which is utilized to imitate the formation mechanism of price dynamics and explain the nonlinear behaviors found in financial time series. We assume that the price fluctuations are caused by the spread of investment information. The cluster of 3D multi-continuum percolation represents the cluster of investors who share the same investment attitude. In this paper, we focus on the paired return series, the paired volatility series, and the paired intrinsic mode functions which are decomposed by empirical mode decomposition. A new cross recurrence quantification analysis is put forward, combining with multiscale cross-sample entropy, to investigate the multiscale synchrony of these paired series from the proposed model. The corresponding research is also carried out for two China stock markets as comparison.

  1. Reducing the default dispense quantity for new opioid analgesic prescriptions: study protocol for a cluster randomised controlled trial.

    Science.gov (United States)

    Bachhuber, Marcus A; Nash, Denis; Southern, William N; Heo, Moonseong; Berger, Matthew; Schepis, Mark; Cunningham, Chinazo O

    2018-04-20

    As opioid analgesic consumption has grown, so have opioid use disorder and opioid-related overdoses. Reducing the quantity of opioid analgesics prescribed for acute non-cancer pain can potentially reduce risks to the individual receiving the prescription and to others who might unintentionally or intentionally consume any leftover tablets. Reducing the default dispense quantity for new opioid analgesic prescriptions in the electronic health record (EHR) is a promising intervention to reduce prescribing. This study is a prospective cluster randomised controlled trial with two parallel arms. Primary care sites (n=32) and emergency departments (n=4) will be randomised in matched pairs to either a modification of the EHR so that new opioid analgesic prescriptions default to a dispense quantity of 10 tablets (intervention) or to no EHR change (control). The dispense quantity will remain fully modifiable by providers in both arms. From 6 months preintervention to 18 months postintervention, patient-level data will be analysed (ie, the patient is the unit of inference). Patient eligibility criteria are: (A) received a new opioid analgesic prescription, defined as no other opioid analgesic prescription in the prior 6 months; (B) age ≥18 years; and (C) no cancer diagnosis within 1 year prior to the new opioid analgesic prescription. The primary outcome will be the quantity of opioid analgesics prescribed in the initial prescription. Secondary outcomes will include opioid analgesic reorders and health service utilisation within 30 days after the initial prescription. Outcomes will be compared between study arms using a difference-in-differences analysis. This study has been approved by the Montefiore Medical Center/Albert Einstein College of Medicine Institutional Review Board with a waiver of informed consent (2016-6036) and is registered on ClinicalTrials.gov (NCT03003832, 6 December 2016). Findings will be disseminated through publication, conferences and meetings

  2. Effectiveness of the Spirometry 360 Quality Improvement Program for Improving Asthma Care: A Cluster Randomized Trial.

    Science.gov (United States)

    Mangione-Smith, Rita; Zhou, Chuan; Corwin, Michael J; Taylor, James A; Rice, Fiona; Stout, James W

    To determine the effectiveness of the Spirometry 360 distance learning quality improvement (QI) program for enhancing the processes and outcomes of care for children with asthma. Cluster randomized controlled trial involving 25 matched pairs of pediatric primary care practices. Practices were recruited from 2 practice-based research networks: the Slone Center Office-based Research Network at Boston University, Boston, Mass, and the Puget Sound Pediatric Research Network, Seattle, Wash. Study participants included providers from one of the 50 enrolled pediatric practices and 626 of their patients with asthma. Process measures assessed included spirometry test quality and appropriate prescription of asthma controller medications. Outcome measures included asthma-specific health-related quality of life, and outpatient, emergency department, and inpatient utilization for asthma. At baseline, 25.4% of spirometry tests performed in control practices and 50.4% of tests performed in intervention practices were of high quality. During the 6-month postintervention period, 28.7% of spirometry tests performed in control practices and 49.9% of tests performed in intervention practices were of high quality. The adjusted difference-of-differences analysis revealed no intervention effect on spirometry test quality. Adjusted differences-of-differences analysis also revealed no intervention effect on appropriate use of controller medications or any of the parent- or patient-reported outcomes examined. In this study, the Spirometry 360 distance learning QI program was ineffective in improving spirometry test quality or parent- or patient-reported outcomes. QI programs like the one assessed here may need to focus on practices with lower baseline performance levels or may need to be tailored for those with higher baseline performance. Copyright © 2017 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

  3. Search for and Investigation of Double Open Clusters

    Directory of Open Access Journals (Sweden)

    Yalyalieva L. N.

    2016-12-01

    Full Text Available The physical and kinematical parameters of three pairs of open clusters, NGC 6755 and Czernik 39, NGC 1857 and Czernik 20, Berkeley 70 and SAI 47, are determined using the data from several photometric catalogs in order to confirm or disprove the binarity of these pairs.

  4. Measurement Error Correction Formula for Cluster-Level Group Differences in Cluster Randomized and Observational Studies

    Science.gov (United States)

    Cho, Sun-Joo; Preacher, Kristopher J.

    2016-01-01

    Multilevel modeling (MLM) is frequently used to detect cluster-level group differences in cluster randomized trial and observational studies. Group differences on the outcomes (posttest scores) are detected by controlling for the covariate (pretest scores) as a proxy variable for unobserved factors that predict future attributes. The pretest and…

  5. An innovative telemedicine knowledge translation program to improve quality of care in intensive care units: protocol for a cluster randomized pragmatic trial

    Directory of Open Access Journals (Sweden)

    Pinto Ruxandra

    2009-02-01

    Full Text Available Abstract Background There are challenges to timely adoption of, and ongoing adherence to, evidence-based practices known to improve patient care in the intensive care unit (ICU. Quality improvement initiatives using a collaborative network approach may increase the use of such practices. Our objective is to evaluate the effectiveness of a novel knowledge translation program for increasing the proportion of patients who appropriately receive the following six evidence-based care practices: venous thromboembolism prophylaxis; ventilator-associated pneumonia prevention; spontaneous breathing trials; catheter-related bloodstream infection prevention; decubitus ulcer prevention; and early enteral nutrition. Methods and design We will conduct a pragmatic cluster randomized active control trial in 15 community ICUs and one academic ICU in Ontario, Canada. The intervention is a multifaceted videoconferenced educational and problem-solving forum to organize knowledge translation strategies, including comparative audit and feedback, educational sessions from content experts, and dissemination of algorithms. Fifteen individual ICUs (clusters will be randomized to receive quality improvement interventions targeting one of the best practices during each of six study phases. Each phase lasts four months during the first study year and three months during the second. At the end of each study phase, ICUs are assigned to an intervention for a best practice not yet received according to a random schedule. The primary analysis will use patient-level process-of-care data to measure the intervention's effect on rates of adoption and adherence of each best practice in the targeted ICU clusters versus controls. Discussion This study design evaluates a new system for knowledge translation and quality improvement across six common ICU problems. All participating ICUs receive quality improvement initiatives during every study phase, improving buy-in. This study design

  6. Simulated top-quark pair production in the CLIC_ILD detector

    CERN Multimedia

    CLIC, Compact Linear Collider Project

    2017-01-01

    Simulated production of a top-quark pair with a nominal collision energy of 3 TeV, in the CLIC_ILD detector. The event display show the reconstructed particles used as input for a jet clustering algorithm.

  7. Reducing Tobacco Use among Low Socio-Economic Status Youth in Delhi, India: Outcomes from Project ACTIVITY, a Cluster Randomized Trial

    Science.gov (United States)

    Harrell, Melissa B.; Arora, Monika; Bassi, Shalini; Gupta, Vinay K.; Perry, Cheryl L.; Reddy, K. Srinath

    2016-01-01

    To test the efficacy of an intervention to reduce tobacco use among youth (10-19 years old) in slum communities in Delhi, India. This community-based cluster-randomized trial included 14 slums composed of purposely built resettlement colonies and adjacent inhabitant-built Jhuggi Jhopris. Youth in the intervention received a 2 year…

  8. Cluster-Randomized Controlled Trial Evaluating the Effectiveness of Computer-Assisted Intervention Delivered by Educators for Children with Speech Sound Disorders

    Science.gov (United States)

    McLeod, Sharynne; Baker, Elise; McCormack, Jane; Wren, Yvonne; Roulstone, Sue; Crowe, Kathryn; Masso, Sarah; White, Paul; Howland, Charlotte

    2017-01-01

    Purpose: The aim was to evaluate the effectiveness of computer-assisted input-based intervention for children with speech sound disorders (SSD). Method: The Sound Start Study was a cluster-randomized controlled trial. Seventy-nine early childhood centers were invited to participate, 45 were recruited, and 1,205 parents and educators of 4- and…

  9. Effectiveness of the universal prevention program 'Healthy School and Drugs': Study protocol of a randomized clustered trial

    Directory of Open Access Journals (Sweden)

    Malmberg Monique

    2010-09-01

    Full Text Available Abstract Background Substance use is highly prevalent among Dutch adolescents. The Healthy School and Drugs program is a nationally implemented school-based prevention program aimed at reducing early and excessive substance use among adolescents. Although the program's effectiveness was tested in a quasi-experimental design before, many program changes were made afterwards. The present study, therefore, aims to test the effects of this widely used, renewed universal prevention program. Methods/Design A randomized clustered trial will be conducted among 3,784 adolescents of 23 secondary schools in The Netherlands. The trial has three conditions; two intervention conditions (i.e., e-learning and integral and a control condition. The e-learning condition consists of three digital learning modules (i.e., about alcohol, tobacco, and marijuana that are sequentially offered over the course of three school years (i.e., grade 1, grade 2, and grade 3. The integral condition consists of parental participation in a parental meeting on substance use, regulation of substance use, and monitoring and counseling of students' substance use at school, over and above the three digital modules. The control condition is characterized as business as usual. Participating schools were randomly assigned to either an intervention or control condition. Participants filled out a digital questionnaire at baseline and will fill out the same questionnaire three more times at follow-up measurements (8, 20, and 32 months after baseline. Outcome variables included in the questionnaire are the percentage of binge drinking (more than five drinks per occasion, the average weekly number of drinks, and the percentage of adolescents who ever drunk a glass of alcohol and the percentage of adolescents who ever smoked a cigarette or a joint respectively for tobacco and marijuana. Discussion This study protocol describes the design of a randomized clustered trial that evaluates the

  10. GestationaL Obesity Weight management: Implementation of National Guidelines (GLOWING): a pilot cluster randomised controlled trial of a guideline implementation intervention for the management of maternal obesity by midwives.

    Science.gov (United States)

    Heslehurst, Nicola; Rankin, Judith; McParlin, Catherine; Sniehotta, Falko F; Howel, Denise; Rice, Stephen; McColl, Elaine

    2018-01-01

    Weight management in pregnancy guidelines exist, although dissemination alone is an ineffective means of implementation. Midwives identify the need for support to overcome complex barriers to practice. An evaluation of an intervention to support midwives' guideline implementation would require a large-scale cluster randomised controlled trial. A pilot study is necessary to explore the feasibility of delivery and evaluation prior to a definitive trial. The GestationaL Obesity Weight management: Implementation of National Guidelines (GLOWING) trial aims to test whether it is feasible and acceptable to deliver a behaviour change intervention to support midwives' implementation of weight management guidelines. GLOWING is a multi-centre parallel group pilot cluster randomised controlled trial comparing the delivery of a behaviour change intervention for midwives versus usual practice. Four NHS Trusts (clusters) will be randomised to intervention and control arms, stratified by size of maternity services. The intervention uses social cognitive theory and consists of face-to-face midwifery training plus information resources for routine practice. The main outcomes are whether the intervention and trial procedures are feasible and acceptable to participants and the feasibility of recruitment and data collection for a definitive trial. Target recruitment involves all eligible midwives in the intervention arm recruited to receive the intervention, 30 midwives and pregnant women per arm for baseline and outcome questionnaire data collection and 20 midwives and women to provide qualitative data. All quantitative and qualitative analyses will be descriptive with the purpose of informing the development of the definitive trial. This pilot study has been developed to support community midwives' implementation of guidelines. Community midwives have been selected as they usually carry out the booking appointment which includes measuring and discussing maternal body mass index. A

  11. Preventing Weight Gain in Women in Rural Communities: A Cluster Randomised Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Catherine Lombard

    2016-01-01

    Full Text Available Obesity is reaching epidemic proportions in both developed and developing countries. Even modest weight gain increases the risk for chronic illness, yet evidence-based interventions to prevent weight gain are rare. This trial will determine if a simple low-intensity intervention can prevent weight gain in women compared to general health information.We conducted a 1-yr pragmatic, cluster randomised controlled trial in 41 Australian towns (clusters randomised using a computer-generated randomisation list for intervention (n = 21 or control (n = 20. Women aged 18 to 50 yr were recruited from the general population to receive a 1-yr self-management lifestyle intervention (HeLP-her consisting of one group session, monthly SMS text messages, one phone coaching session, and a program manual, or to a control group receiving one general women's health education session. From October 2012 to April 2014 we studied 649 women, mean age 39.6 yr (+/- SD 6.7 and BMI of 28.8 kg/m(2 (+/- SD 6.9 with the primary outcome weight change between groups at 1 yr. The mean change in the control was +0.44 kg (95% CI -0.09 to 0.97 and in the intervention group -0.48 kg (95% CI -0.99 to 0.03 with an unadjusted between group difference of -0.92 kg (95% CI -1.67 to -0.16 or -0.87 kg (95% CI -1.62 to -0.13 adjusted for baseline values and clustering. Secondary outcomes included improved diet quality and greater self-management behaviours. The intervention appeared to be equally efficacious across all age, BMI, income, and education subgroups. Loss to follow-up included 23.8% in the intervention group and 21.8% in the control group and was within the anticipated range. Limitations include lack of sensitive tools to measure the small changes to energy intake and physical activity. Those who gained weight may have been less inclined to return for 1 yr weight measures.A low intensity lifestyle program can prevent the persistent weight gain observed in women. Key features included

  12. Home-based versus mobile clinic HIV testing and counseling in rural Lesotho: a cluster-randomized trial.

    Directory of Open Access Journals (Sweden)

    Niklaus Daniel Labhardt

    2014-12-01

    Full Text Available The success of HIV programs relies on widely accessible HIV testing and counseling (HTC services at health facilities as well as in the community. Home-based HTC (HB-HTC is a popular community-based approach to reach persons who do not test at health facilities. Data comparing HB-HTC to other community-based HTC approaches are very limited. This trial compares HB-HTC to mobile clinic HTC (MC-HTC.The trial was powered to test the hypothesis of higher HTC uptake in HB-HTC campaigns than in MC-HTC campaigns. Twelve clusters were randomly allocated to HB-HTC or MC-HTC. The six clusters in the HB-HTC group received 30 1-d multi-disease campaigns (five villages per cluster that delivered services by going door-to-door, whereas the six clusters in MC-HTC group received campaigns involving community gatherings in the 30 villages with subsequent service provision in mobile clinics. Time allocation and human resources were standardized and equal in both groups. All individuals accessing the campaigns with unknown HIV status or whose last HIV test was >12 wk ago and was negative were eligible. All outcomes were assessed at the individual level. Statistical analysis used multivariable logistic regression. Odds ratios and p-values were adjusted for gender, age, and cluster effect. Out of 3,197 participants from the 12 clusters, 2,563 (80.2% were eligible (HB-HTC: 1,171; MC-HTC: 1,392. The results for the primary outcomes were as follows. Overall HTC uptake was higher in the HB-HTC group than in the MC-HTC group (92.5% versus 86.7%; adjusted odds ratio [aOR]: 2.06; 95% CI: 1.18-3.60; p = 0. 011. Among adolescents and adults ≥ 12 y, HTC uptake did not differ significantly between the two groups; however, in children <12 y, HTC uptake was higher in the HB-HTC arm (87.5% versus 58.7%; aOR: 4.91; 95% CI: 2.41-10.0; p<0.001. Out of those who took up HTC, 114 (4.9% tested HIV-positive, 39 (3.6% in the HB-HTC arm and 75 (6.2% in the MC-HTC arm (aOR: 0.64; 95% CI

  13. Community-based trial of annual versus biannual single-dose ivermectin plus albendazole against Wuchereria bancrofti infection in human and mosquito populations: study protocol for a cluster randomised controlled trial.

    Science.gov (United States)

    de Souza, Dziedzom K; Ahorlu, Collins S; Adu-Amankwah, Susan; Otchere, Joseph; Mensah, Sedzro K; Larbi, Irene A; Mensah, George E; Biritwum, Nana-Kwadwo; Boakye, Daniel A

    2017-10-02

    The Global Programme for the Elimination of Lymphatic Filariasis (GPELF) has been in operation since the year 2000, with the aim of eliminating the disease by the year 2020, following five to six rounds of effective annual mass drug administration (MDA). The treatment regimen is ivermectin (IVM) in combination with diethylcarbamazine (DEC) or albendazole (ALB). In Ghana, MDA has been undertaken since 2001. While the disease has been eliminated in many areas, transmission has persisted in some implementation units that had experienced 15 or more rounds of MDA. Thus, new intervention strategies could eliminate residual infection in areas of persistent transmission and speed up the lymphatic filariasis (LF)-elimination process. This study, therefore, seeks to test the hypothesis that biannual treatment of LF-endemic communities will accelerate the interruption of LF in areas of persistent transmission. A cluster randomised trial will be implemented in LF-endemic communities in Ghana. The interventions will be yearly or twice-yearly MDA delivered to entire endemic communities. Allocation to study group will be by clusters identified using the prevalence of LF. Clusters will be randomised to one of two groups: receiving either (1) annual treatment with IVM + ALB or (2) annual MDA with IVM + ALB, followed by an additional MDA 6 months later. The primary outcome measure is the prevalence of LF infection, assessed by four cross-sectional surveys. Entomological assessments will also be undertaken to evaluate the transmission intensity of the disease in the study clusters. Costs and cost-effectiveness will be evaluated. Among a random subsample of participants, microfilaria prevalence will be assessed longitudinally. A nested process evaluation, using semi-structured interviews, focus group discussions and a stakeholder analysis, will investigate the community acceptability, feasibility and scale-up of each delivery system. It is expected that this study will add to

  14. An adaptive clustering algorithm for image matching based on corner feature

    Science.gov (United States)

    Wang, Zhe; Dong, Min; Mu, Xiaomin; Wang, Song

    2018-04-01

    The traditional image matching algorithm always can not balance the real-time and accuracy better, to solve the problem, an adaptive clustering algorithm for image matching based on corner feature is proposed in this paper. The method is based on the similarity of the matching pairs of vector pairs, and the adaptive clustering is performed on the matching point pairs. Harris corner detection is carried out first, the feature points of the reference image and the perceived image are extracted, and the feature points of the two images are first matched by Normalized Cross Correlation (NCC) function. Then, using the improved algorithm proposed in this paper, the matching results are clustered to reduce the ineffective operation and improve the matching speed and robustness. Finally, the Random Sample Consensus (RANSAC) algorithm is used to match the matching points after clustering. The experimental results show that the proposed algorithm can effectively eliminate the most wrong matching points while the correct matching points are retained, and improve the accuracy of RANSAC matching, reduce the computation load of whole matching process at the same time.

  15. Social Dancing and Incidence of Falls in Older Adults: A Cluster Randomised Controlled Trial.

    Science.gov (United States)

    Merom, Dafna; Mathieu, Erin; Cerin, Ester; Morton, Rachael L; Simpson, Judy M; Rissel, Chris; Anstey, Kaarin J; Sherrington, Catherine; Lord, Stephen R; Cumming, Robert G

    2016-08-01

    The prevention of falls among older people is a major public health challenge. Exercises that challenge balance are recognized as an efficacious fall prevention strategy. Given that small-scale trials have indicated that diverse dance styles can improve balance and gait of older adults, two of the strongest risk factors for falls in older people, this study aimed to determine whether social dance is effective in i) reducing the number of falls and ii) improving physical and cognitive fall-related risk factors. A parallel two-arm cluster randomized controlled trial was undertaken in 23 self-care retirement villages (clusters) around Sydney, Australia. Eligible villages had to have an appropriate hall for dancing, house at least 60 residents, and not be currently offering dance as a village activity. Retirement villages were randomised using a computer generated randomisation method, constrained using minimisation. Eligible participants had to be a resident of the village, be able to walk at least 50 m, and agree to undergo physical and cognitive testing without cognitive impairment. Residents of intervention villages (12 clusters) were offered twice weekly one-hour social dancing classes (folk or ballroom dancing) over 12 mo (80 h in total). Programs were standardized across villages and were delivered by eight dance teachers. Participants in the control villages (11 clusters) were advised to continue with their regular activities. falls during the 12 mo trial and Trail Making Tests. The Physiological Performance Assessment (i.e., postural sway, proprioception, reaction time, leg strength) and the Short Physical Performance Battery; health-related physical and mental quality of life from the Short-Form 12 (SF-12) Survey. Data on falls were obtained from 522 of 530 (98%) randomised participants (mean age 78 y, 85% women) and 424 (80%) attended the 12-mo reassessment, which was lower among folk dance participants (71%) than ballroom dancing (82%) or control

  16. Social Dancing and Incidence of Falls in Older Adults: A Cluster Randomised Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Dafna Merom

    2016-08-01

    Full Text Available The prevention of falls among older people is a major public health challenge. Exercises that challenge balance are recognized as an efficacious fall prevention strategy. Given that small-scale trials have indicated that diverse dance styles can improve balance and gait of older adults, two of the strongest risk factors for falls in older people, this study aimed to determine whether social dance is effective in i reducing the number of falls and ii improving physical and cognitive fall-related risk factors.A parallel two-arm cluster randomized controlled trial was undertaken in 23 self-care retirement villages (clusters around Sydney, Australia. Eligible villages had to have an appropriate hall for dancing, house at least 60 residents, and not be currently offering dance as a village activity. Retirement villages were randomised using a computer generated randomisation method, constrained using minimisation. Eligible participants had to be a resident of the village, be able to walk at least 50 m, and agree to undergo physical and cognitive testing without cognitive impairment. Residents of intervention villages (12 clusters were offered twice weekly one-hour social dancing classes (folk or ballroom dancing over 12 mo (80 h in total. Programs were standardized across villages and were delivered by eight dance teachers. Participants in the control villages (11 clusters were advised to continue with their regular activities.falls during the 12 mo trial and Trail Making Tests.The Physiological Performance Assessment (i.e., postural sway, proprioception, reaction time, leg strength and the Short Physical Performance Battery; health-related physical and mental quality of life from the Short-Form 12 (SF-12 Survey. Data on falls were obtained from 522 of 530 (98% randomised participants (mean age 78 y, 85% women and 424 (80% attended the 12-mo reassessment, which was lower among folk dance participants (71% than ballroom dancing (82% or control

  17. Improving person-centred care in nursing homes through dementia-care mapping: design of a cluster-randomised controlled trial

    Science.gov (United States)

    2012-01-01

    Background The effectiveness and efficiency of nursing-home dementia care are suboptimal: there are high rates of neuropsychiatric symptoms among the residents and work-related stress among the staff. Dementia-care mapping is a person-centred care method that may alleviate both the resident and the staff problems. The main objective of this study is to evaluate the effectiveness and cost-effectiveness of dementia-care mapping in nursing-home dementia care. Methods/Design The study is a cluster-randomised controlled trial, with nursing homes grouped in clusters. Studywise minimisation is the allocation method. Nursing homes in the intervention group will receive a dementia-care-mapping intervention, while the control group will receive usual care. The primary outcome measure is resident agitation, to be assessed with the Cohen-Mansfield Agitation Inventory. The secondary outcomes are resident neuropsychiatric symptoms, assessed with the Neuropsychiatric Inventory - Nursing Homes and quality of life, assessed with Qualidem and the EQ-5D. The staff outcomes are stress reactions, job satisfaction and job-stress-related absenteeism, and staff turnover rate, assessed with the Questionnaire about Experience and Assessment of Work, the General Health Questionnaire-12, and the Maastricht Job Satisfaction Scale for Health Care, respectively. We will collect the data from the questionnaires and electronic registration systems. We will employ linear mixed-effect models and cost-effectiveness analyses to evaluate the outcomes. We will use structural equation modelling in the secondary analysis to evaluate the plausibility of a theoretical model regarding the effectiveness of the dementia-care mapping intervention. We will set up process analyses, including focus groups with staff, to determine the relevant facilitators of and barriers to implementing dementia-care mapping broadly. Discussion A novelty of dementia-care mapping is that it offers an integral person

  18. Improving person-centred care in nursing homes through dementia-care mapping: design of a cluster-randomised controlled trial

    Directory of Open Access Journals (Sweden)

    van de Ven Geertje

    2012-01-01

    Full Text Available Abstract Background The effectiveness and efficiency of nursing-home dementia care are suboptimal: there are high rates of neuropsychiatric symptoms among the residents and work-related stress among the staff. Dementia-care mapping is a person-centred care method that may alleviate both the resident and the staff problems. The main objective of this study is to evaluate the effectiveness and cost-effectiveness of dementia-care mapping in nursing-home dementia care. Methods/Design The study is a cluster-randomised controlled trial, with nursing homes grouped in clusters. Studywise minimisation is the allocation method. Nursing homes in the intervention group will receive a dementia-care-mapping intervention, while the control group will receive usual care. The primary outcome measure is resident agitation, to be assessed with the Cohen-Mansfield Agitation Inventory. The secondary outcomes are resident neuropsychiatric symptoms, assessed with the Neuropsychiatric Inventory - Nursing Homes and quality of life, assessed with Qualidem and the EQ-5D. The staff outcomes are stress reactions, job satisfaction and job-stress-related absenteeism, and staff turnover rate, assessed with the Questionnaire about Experience and Assessment of Work, the General Health Questionnaire-12, and the Maastricht Job Satisfaction Scale for Health Care, respectively. We will collect the data from the questionnaires and electronic registration systems. We will employ linear mixed-effect models and cost-effectiveness analyses to evaluate the outcomes. We will use structural equation modelling in the secondary analysis to evaluate the plausibility of a theoretical model regarding the effectiveness of the dementia-care mapping intervention. We will set up process analyses, including focus groups with staff, to determine the relevant facilitators of and barriers to implementing dementia-care mapping broadly. Discussion A novelty of dementia-care mapping is that it offers an

  19. Binding energy of large icosahedral and cuboctahedral Lennard-Jones clusters

    International Nuclear Information System (INIS)

    Northby, J.A.; Xie, J.

    1989-01-01

    It is widely believed that the lowest energy configurations for small rare gas clusters have icosahedral symmetry. This contrasts with the bulk crystal structures which have cuboctahedral fcc symmetry. It is of interest to understand the transition between this finite and bulk behavior. To model this transition in rare gas clusters we have undertaken optimization studies within the Lennard-Jones pair potential model. Using a combination of Monte Carlo and Partan Search optimization methods, the lowest energy relaxed structures of Lennard-Jones clusters having icosahedral and cuboctahedral symmetry were found. Studies were performed for complete shell clusters ranging in size from one shell having 13 atoms to 14 shells having 10,179 atoms. It was found that the icosahedral structures are lower in energy than the cuboctahedral structures for cluster sizes having 13 shells or fewer. Additional studies were performed using the more accurate Aziz-Chen [HFD-C] pair potential parameterized for argon. The conclusions appear to be relatively insensitive to the form of the potential. (orig.)

  20. From collisions to clusters

    DEFF Research Database (Denmark)

    Loukonen, Ville; Bork, Nicolai; Vehkamaki, Hanna

    2014-01-01

    -principles molecular dynamics collision simulations of (sulphuric acid)1(water)0, 1 + (dimethylamine) → (sulphuric acid)1(dimethylamine)1(water)0, 1 cluster formation processes. The simulations indicate that the sticking factor in the collisions is unity: the interaction between the molecules is strong enough...... control. As a consequence, the clusters show very dynamic ion pair structure, which differs from both the static structure optimisation calculations and the equilibrium first-principles molecular dynamics simulations. In some of the simulation runs, water mediates the proton transfer by acting as a proton...... to overcome the possible initial non-optimal collision orientations. No post-collisional cluster break up is observed. The reasons for the efficient clustering are (i) the proton transfer reaction which takes place in each of the collision simulations and (ii) the subsequent competition over the proton...

  1. Identifying seizure clusters in patients with psychogenic nonepileptic seizures.

    Science.gov (United States)

    Baird, Grayson L; Harlow, Lisa L; Machan, Jason T; Thomas, Dave; LaFrance, W C

    2017-08-01

    The present study explored how seizure clusters may be defined for those with psychogenic nonepileptic seizures (PNES), a topic for which there is a paucity of literature. The sample was drawn from a multisite randomized clinical trial for PNES; seizure data are from participants' seizure diaries. Three possible cluster definitions were examined: 1) common clinical definition, where ≥3 seizures in a day is considered a cluster, along with two novel statistical definitions, where ≥3 seizures in a day are considered a cluster if the observed number of seizures statistically exceeds what would be expected relative to a patient's: 1) average seizure rate prior to the trial, 2) observed seizure rate for the previous seven days. Prevalence of clusters was 62-68% depending on cluster definition used, and occurrence rate of clusters was 6-19% depending on cluster definition. Based on these data, clusters seem to be common in patients with PNES, and more research is needed to identify if clusters are related to triggers and outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Evaluation of a self-management patient education program for patients with chronic heart failure undergoing inpatient cardiac rehabilitation: study protocol of a cluster randomized controlled trial.

    Science.gov (United States)

    Meng, Karin; Musekamp, Gunda; Seekatz, Bettina; Glatz, Johannes; Karger, Gabriele; Kiwus, Ulrich; Knoglinger, Ernst; Schubmann, Rainer; Westphal, Ronja; Faller, Hermann

    2013-08-23

    Chronic heart failure requires a complex treatment regimen on a life-long basis. Therefore, self-care/self-management is an essential part of successful treatment and comprehensive patient education is warranted. However, specific information on program features and educational strategies enhancing treatment success is lacking. This trial aims to evaluate a patient-oriented and theory-based self-management educational group program as compared to usual care education during inpatient cardiac rehabilitation in Germany. The study is a multicenter cluster randomized controlled trial in four cardiac rehabilitation clinics. Clusters are patient education groups that comprise HF patients recruited within 2 weeks after commencement of inpatient cardiac rehabilitation. Cluster randomization was chosen for pragmatic reasons, i.e. to ensure a sufficient number of eligible patients to build large-enough educational groups and to prevent contamination by interaction of patients from different treatment allocations during rehabilitation. Rehabilitants with chronic systolic heart failure (n = 540) will be consecutively recruited for the study at the beginning of inpatient rehabilitation. Data will be assessed at admission, at discharge and after 6 and 12 months using patient questionnaires. In the intervention condition, patients receive the new patient-oriented self-management educational program, whereas in the control condition, patients receive a short lecture-based educational program (usual care). The primary outcome is patients' self-reported self-management competence. Secondary outcomes include behavioral determinants and self-management health behavior (symptom monitoring, physical activity, medication adherence), health-related quality of life, and treatment satisfaction. Treatment effects will be evaluated separately for each follow-up time point using multilevel regression analysis, and adjusting for baseline values. This study evaluates the effectiveness of a

  3. Evaluation of a self-management patient education program for patients with fibromyalgia syndrome: study protocol of a cluster randomized controlled trial.

    Science.gov (United States)

    Musekamp, Gunda; Gerlich, Christian; Ehlebracht-König, Inge; Faller, Hermann; Reusch, Andrea

    2016-02-03

    Fibromyalgia syndrome (FMS) is a complex chronic condition that makes high demands on patients' self-management skills. Thus, patient education is considered an important component of multimodal therapy, although evidence regarding its effectiveness is scarce. The main objective of this study is to assess the effectiveness of an advanced self-management patient education program for patients with FMS as compared to usual care in the context of inpatient rehabilitation. We conducted a multicenter cluster randomized controlled trial in 3 rehabilitation clinics. Clusters are groups of patients with FMS consecutively recruited within one week after admission. Patients of the intervention group receive the advanced multidisciplinary self-management patient education program (considering new knowledge on FMS, with a focus on transfer into everyday life), whereas patients in the control group receive standard patient education programs including information on FMS and coping with pain. A total of 566 patients are assessed at admission, at discharge and after 6 and 12 months, using patient reported questionnaires. Primary outcomes are patients' disease- and treatment-specific knowledge at discharge and self-management skills after 6 months. Secondary outcomes include satisfaction, attitudes and coping competences, health-promoting behavior, psychological distress, health impairment and participation. Treatment effects between groups are evaluated using multilevel regression analysis adjusting for baseline values. The study evaluates the effectiveness of a self-management patient education program for patients with FMS in the context of inpatient rehabilitation in a cluster randomized trial. Study results will show whether self-management patient education is beneficial for this group of patients. German Clinical Trials Register, DRKS00008782 , Registered 8 July 2015.

  4. Indirect photometric detection of boron cluster anions electrophoretically separated in methanol.

    Science.gov (United States)

    Vítová, Lada; Fojt, Lukáš; Vespalec, Radim

    2014-04-18

    3,5-Dinitrobenzoate and picrate are light absorbing anions pertinent to indirect photometric detection of boron cluster anions in buffered methanolic background electrolytes (BGEs). Tris(hydroxymethyl)aminomethane and morpholine have been used as buffering bases, which eliminated baseline steps, and minimized the baseline noise. In methanolic BGEs, mobilities of boron cluster anions depend on both ionic constituents of the BGE buffer. This dependence can be explained by ion pair interaction of detected anions with BGE cations, which are not bonded into ion pairs with the BGE anions. The former ion pair interaction decreases sensitivity of the indirect photometric detection. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Effects of ion pairs on the dynamics of erbium doped fiber laser in the inhomogeneous model

    International Nuclear Information System (INIS)

    Keyvaninia, Sh.; Karvar, M.; Bahrampour, A.

    2006-01-01

    In a high concentration erbium doped fiber, the erbium ions are so closed together that the ion pairs and clusters are formed. In such fiber amplifiers, the ion pairs and clusters acting as a saturable absorber are distributed along the fiber laser. The inhomogeneous rate equations for the laser modes in a high-concentration EDFA are written. The governing equations are an uncountable system of partial differential equations. For the first time we introduced an approximation method that the system of partial differential equations is converted to a finite system of ordinary differential equations. The effects of ion pairs concentration on erbium doped fiber are analyzed that is in good agreement whit the experimental result.

  6. Dengue occurrence relations and serology: cross-sectional analysis of results from the Guerrero State, Mexico, baseline for a cluster-randomised controlled trial of community mobilisation for dengue prevention.

    Science.gov (United States)

    Nava-Aguilera, Elizabeth; Morales-Pérez, Arcadio; Balanzar-Martínez, Alejandro; Rodríguez-Ramírez, Ofelia; Jiménez-Alejo, Abel; Flores-Moreno, Miguel; Gasga-Salinas, David; Legorreta-Soberanis, José; Paredes-Solís, Sergio; Morales-Nava, Pedro Antonio; de Lourdes Soto-Ríos, María; Ledogar, Robert J; Coloma, Joséfina; Harris, Eva; Andersson, Neil

    2017-05-30

    The Mexican arm of the Camino Verde trial of community mobilisation for dengue prevention covered three coastal regions of Guerrero state: Acapulco, Costa Grande and Costa Chica. A baseline cross-sectional survey provided data for community mobilisation and for adapting the intervention design to concrete conditions in the intervention areas. Trained field teams constructed community profiles in randomly selected clusters, based on observation and key informant interviews. In each household they carried out an entomological inspection of water containers, collected information on socio-demographic variables and cases of dengue illness among household members in the last year, and gathered paired saliva samples from children aged 3-9 years, which were subjected to ELISA testing to detect recent dengue infection. We examined associations with dengue illness and recent dengue infection in bivariate and then multivariate analysis. In 70/90 clusters, key informants were unable to identify any organized community groups. Some 1.9% (1029/55,723) of the household population reported dengue illness in the past year, with a higher rate in Acapulco region. Among children 3-9 years old, 6.1% (392/6382) had serological evidence of recent dengue infection. In all three regions, household use of anti-mosquito products, household heads working, and households having less than 5 members were associated with self-reported dengue illness. In Acapulco region, people aged less than 25 years, those with a more educated household head and those from urban sites were also more likely to report dengue illness, while in Costa Chica and Costa Grande, females were more likely to report dengue illness. Among children aged 3-9 years, those aged 3-4 years and those living in Acapulco were more likely to have evidence of recent dengue infection. The evidence from the baseline survey provided important support for the design and implementation of the trial intervention. The weakness of

  7. Multifaceted intervention to enhance the screening and care of hospitalised malnourished children: study protocol for the PREDIRE cluster randomized controlled trial

    Science.gov (United States)

    2013-01-01

    Background Hospital malnutrition is an underestimated problem and as many as half of malnourished patients do not receive appropriate treatment. In order to extend the management of malnutrition in health care facilities, multidisciplinary teams focusing on clinical nutrition were established in France. The establishment of such teams within hospital facilities remains nonetheless difficult. We have consequently developed a multifaceted intervention coordinated by a Nutritional Support Team (NST). Our study aims to evaluate the impact of this multifaceted intervention coordinated by a NST, in adherence to recommended practices for the care of malnourished children, among health care workers of a paediatric university hospital. Methods/design We carried out 1) a six-month observational phase focusing on the medical care procedures relative to malnourished children followed by 2) a cluster randomised controlled trial phase to evaluate the impact of a multidisciplinary nutrition team over an 18 month time frame. Based on power analyses and assuming a conservative intracluster correlation coefficient, 1289 children were needed to detect a 25% difference in rates between the two groups of the cluster trial. The implementation of our intervention was coordinated by the NST and had three major components: a) access to a computerised malnutrition screening system associated with an automatic alert system, b) an awareness campaign directed toward the health care workers and c) a leadership based strategy. Main outcomes included the number of daily weighings during hospitalisation, the investigation of malnutrition etiology and the management of malnutrition by a dietician and/or the NST. Due to the clustered nature of the data with children nested in departments, a generalized estimated equations approach will be used to analyse the impact of the multifaceted intervention on primary and secondary outcomes. Discussion Our results will provide an overall response regarding

  8. CAUGHT IN THE ACT: THE ASSEMBLY OF MASSIVE CLUSTER GALAXIES AT z = 1.62

    International Nuclear Information System (INIS)

    Lotz, Jennifer M.; Ferguson, Henry C.; Grogin, Norman; Koekemoer, Anton M.; Papovich, Casey; Tran, Kim-Vy; Faber, S. M.; Guo Yicheng; Kocevski, Dale; Lee, Kyoung-Soo; McIntosh, Daniel; Momcheva, Ivelina; Rudnick, Gregory; Saintonge, Amelie; Van der Wel, Arjen; Willmer, Christopher

    2013-01-01

    We present the recent merger history of massive galaxies in a spectroscopically confirmed proto-cluster at z = 1.62. Using Hubble Space Telescope WFC3 near-infrared imaging from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, we select cluster and z ∼ 1.6 field galaxies with M star ≥ 3 × 10 10 M ☉ , to determine the frequency of double nuclei or close companions within projected separations less than 20 kpc co-moving. We find that four out of five spectroscopically confirmed massive proto-cluster galaxies have double nuclei, and 57 +13 -14 % of all M star ≥ 3 × 10 10 M ☉ cluster candidates are observed in either close pair systems or have double nuclei. In contrast, only 11% ± 3% of the field galaxies are observed in close pair/double nuclei systems. After correcting for the contribution from random projections, the implied merger rate per massive galaxy in the proto-cluster is ∼3-10 times higher than the merger rate of massive field galaxies at z ∼ 1.6. Close pairs in the cluster have minor merger stellar mass ratios (M primary : M satellite ≥ 4), while the field pairs consist of both major and minor mergers. At least half of the cluster mergers are gas-poor, as indicated by their red colors and low 24 μm fluxes. Two of the double-nucleated cluster members have X-ray detected active galactic nuclei with L x > 10 43 erg s –1 , and are strong candidates for dual or offset super-massive black holes. We conclude that the massive z = 1.62 proto-cluster galaxies are undergoing accelerated assembly via minor mergers, and discuss the implications for galaxy evolution in proto-cluster environments

  9. A cluster randomised controlled effectiveness trial evaluating perinatal home visiting among South African mothers/infants.

    Directory of Open Access Journals (Sweden)

    Mary Jane Rotheram-Borus

    Full Text Available Interventions are needed to reduce poor perinatal health. We trained community health workers (CHWs as home visitors to address maternal/infant risks.In a cluster randomised controlled trial in Cape Town townships, neighbourhoods were randomised within matched pairs to 1 the control, healthcare at clinics (n = 12 neighbourhoods; n = 594 women, or 2 a home visiting intervention by CBW trained in cognitive-behavioural strategies to address health risks (by the Philani Maternal, Child Health and Nutrition Programme, in addition to clinic care (n = 12 neighbourhoods; n = 644 women. Participants were assessed during pregnancy (2% refusal and 92% were reassessed at two weeks post-birth, 88% at six months and 84% at 18 months later. We analysed 32 measures of maternal/infant well-being over the 18 month follow-up period using longitudinal random effects regressions. A binomial test for correlated outcomes evaluated overall effectiveness over time. The 18 month post-birth assessment outcomes also were examined alone and as a function of the number of home visits received.Benefits were found on 7 of 32 measures of outcomes, resulting in significant overall benefits for the intervention compared to the control when using the binomial test (p = 0.008; nevertheless, no effects were observed when only the 18 month outcomes were analyzed. Benefits on individual outcomes were related to the number of home visits received. Among women living with HIV, intervention mothers were more likely to implement the PMTCT regimens, use condoms during all sexual episodes (OR = 1.25; p = 0.014, have infants with healthy weight-for-age measurements (OR = 1.42; p = 0.045, height-for-age measurements (OR = 1.13, p<0.001, breastfeed exclusively for six months (OR = 3.59; p<0.001, and breastfeed longer (OR = 3.08; p<0.001. Number of visits was positively associated with infant birth weight ≥2500 grams (OR = 1.07; p = 0

  10. Hierarchical Star Formation in Turbulent Media: Evidence from Young Star Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Grasha, K.; Calzetti, D. [Astronomy Department, University of Massachusetts, Amherst, MA 01003 (United States); Elmegreen, B. G. [IBM Research Division, T.J. Watson Research Center, Yorktown Heights, NY (United States); Adamo, A.; Messa, M. [Department of Astronomy, The Oskar Klein Centre, Stockholm University, Stockholm (Sweden); Aloisi, A.; Bright, S. N.; Lee, J. C.; Ryon, J. E.; Ubeda, L. [Space Telescope Science Institute, Baltimore, MD (United States); Cook, D. O. [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA (United States); Dale, D. A. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY (United States); Fumagalli, M. [Institute for Computational Cosmology and Centre for Extragalactic Astronomy, Department of Physics, Durham University, Durham (United Kingdom); Gallagher III, J. S. [Department of Astronomy, University of Wisconsin–Madison, Madison, WI (United States); Gouliermis, D. A. [Zentrum für Astronomie der Universität Heidelberg, Institut für Theoretische Astrophysik, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Grebel, E. K. [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12-14, D-69120, Heidelberg (Germany); Kahre, L. [Department of Astronomy, New Mexico State University, Las Cruces, NM (United States); Kim, H. [Gemini Observatory, La Serena (Chile); Krumholz, M. R., E-mail: kgrasha@astro.umass.edu [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia)

    2017-06-10

    We present an analysis of the positions and ages of young star clusters in eight local galaxies to investigate the connection between the age difference and separation of cluster pairs. We find that star clusters do not form uniformly but instead are distributed so that the age difference increases with the cluster pair separation to the 0.25–0.6 power, and that the maximum size over which star formation is physically correlated ranges from ∼200 pc to ∼1 kpc. The observed trends between age difference and separation suggest that cluster formation is hierarchical both in space and time: clusters that are close to each other are more similar in age than clusters born further apart. The temporal correlations between stellar aggregates have slopes that are consistent with predictions of turbulence acting as the primary driver of star formation. The velocity associated with the maximum size is proportional to the galaxy’s shear, suggesting that the galactic environment influences the maximum size of the star-forming structures.

  11. The effectiveness of a construction worksite prevention program on work ability, health, and sick leave: Results from a cluster randomized controlled trial

    NARCIS (Netherlands)

    Oude Hengel, K.M.; Blatter, B.M.; Molen, H.F. van der; Bongers, P.M.; Beek, A.J. van der

    2013-01-01

    Objective This study aimed to investigate the effectiveness of a prevention program on work ability, health, and sick leave targeted at construction worksites. Methods A total of 15 departments (N=297 workers) from 6 construction companies participated in this cluster randomized controlled trial and

  12. Laser ionization of molecular clusters

    International Nuclear Information System (INIS)

    Desai, S.; Feigerle, C.S.

    1995-01-01

    Multiphoton ionization coupled with mass spectrometry was used to investigate molecular cluster distributions. Three examples will be discussed in this presentation. First, in studies of neat nitric oxide clusters, (NO) m , an interesting odd-even intensity alternation was observed and will be discussed in terms of electron-pairing considerations. In a separate study, the binary clusters comprising nitric oxide and methane preferentially form a stoichiometric cluster made up of repeating units of (NO) 2 CH 4 . These presumably represent a particularly strongly bound open-quotes van der Waalsclose quotes subunit. Finally, in similar studies of neat carbon disulfide clusters, (CS 2 ) m , additional photon absorption after the two-photon ionization step stimulates a series of intracluster ion-molecular reactions leading to formation of S m + and (CS) m + polymers, as well as intermediate species such as S m + (CS 2 ). This molecular cluster analogue of open-quotes laser snowclose quotes will be described in detail

  13. A Comparison of Two Approaches to Beta-Flexible Clustering.

    Science.gov (United States)

    Belbin, Lee; And Others

    1992-01-01

    A method for hierarchical agglomerative polythetic (multivariate) clustering, based on unweighted pair group using arithmetic averages (UPGMA) is compared with the original beta-flexible technique, a weighted average method. Reasons the flexible UPGMA strategy is recommended are discussed, focusing on the ability to recover cluster structure over…

  14. Calculating the enthalpy of vaporization for ionic liquid clusters.

    Science.gov (United States)

    Kelkar, Manish S; Maginn, Edward J

    2007-08-16

    Classical atomistic simulations are used to compute the enthalpy of vaporization of a series of ionic liquids composed of 1-alkyl-3-methylimidazolium cations paired with the bis(trifluoromethylsulfonyl)imide anion. The calculations show that the enthalpy of vaporization is lowest for neutral ion pairs. The enthalpy of vaporization increases by about 40 kJ/mol with the addition of each ion pair to the vaporizing cluster. Non-neutral clusters have much higher vaporization enthalpies than their neutral counterparts and thus are not expected to make up a significant fraction of volatile species. The enthalpy of vaporization increases slightly as the cation alkyl chain length increases and as temperature decreases. The calculated vaporization enthalpies are consistent with two sets of recent experimental measurements as well as with previous atomistic simulations.

  15. Exergaming and older adult cognition: a cluster randomized clinical trial.

    Science.gov (United States)

    Anderson-Hanley, Cay; Arciero, Paul J; Brickman, Adam M; Nimon, Joseph P; Okuma, Naoko; Westen, Sarah C; Merz, Molly E; Pence, Brandt D; Woods, Jeffrey A; Kramer, Arthur F; Zimmerman, Earl A

    2012-02-01

    Dementia cases may reach 100 million by 2050. Interventions are sought to curb or prevent cognitive decline. Exercise yields cognitive benefits, but few older adults exercise. Virtual reality-enhanced exercise or "exergames" may elicit greater participation. To test the following hypotheses: (1) stationary cycling with virtual reality tours ("cybercycle") will enhance executive function and clinical status more than traditional exercise; (2) exercise effort will explain improvement; and (3) brain-derived neurotrophic growth factor (BDNF) will increase. Multi-site cluster randomized clinical trial (RCT) of the impact of 3 months of cybercycling versus traditional exercise, on cognitive function in older adults. Data were collected in 2008-2010; analyses were conducted in 2010-2011. 102 older adults from eight retirement communities enrolled; 79 were randomized and 63 completed. A recumbent stationary ergometer was utilized; virtual reality tours and competitors were enabled on the cybercycle. Executive function (Color Trails Difference, Stroop C, Digits Backward); clinical status (mild cognitive impairment; MCI); exercise effort/fitness; and plasma BDNF. Intent-to-treat analyses, controlling for age, education, and cluster randomization, revealed a significant group X time interaction for composite executive function (p=0.002). Cybercycling yielded a medium effect over traditional exercise (d=0.50). Cybercyclists had a 23% relative risk reduction in clinical progression to MCI. Exercise effort and fitness were comparable, suggesting another underlying mechanism. A significant group X time interaction for BDNF (p=0.05) indicated enhanced neuroplasticity among cybercyclists. Cybercycling older adults achieved better cognitive function than traditional exercisers, for the same effort, suggesting that simultaneous cognitive and physical exercise has greater potential for preventing cognitive decline. This study is registered at Clinicaltrials.gov NCT01167400. Copyright

  16. NUCORE - A system for nuclear structure calculations with cluster-core models

    International Nuclear Information System (INIS)

    Heras, C.A.; Abecasis, S.M.

    1982-01-01

    Calculation of nuclear energy levels and their electromagnetic properties, modelling the nucleus as a cluster of a few particles and/or holes interacting with a core which in turn is modelled as a quadrupole vibrator (cluster-phonon model). The members of the cluster interact via quadrupole-quadrupole and pairing forces. (orig.)

  17. Cluster consensus in discrete-time networks of multiagents with inter-cluster nonidentical inputs.

    Science.gov (United States)

    Han, Yujuan; Lu, Wenlian; Chen, Tianping

    2013-04-01

    In this paper, cluster consensus of multiagent systems is studied via inter-cluster nonidentical inputs. Here, we consider general graph topologies, which might be time-varying. The cluster consensus is defined by two aspects: intracluster synchronization, the state at which differences between each pair of agents in the same cluster converge to zero, and inter-cluster separation, the state at which agents in different clusters are separated. For intra-cluster synchronization, the concepts and theories of consensus, including the spanning trees, scramblingness, infinite stochastic matrix product, and Hajnal inequality, are extended. As a result, it is proved that if the graph has cluster spanning trees and all vertices self-linked, then the static linear system can realize intra-cluster synchronization. For the time-varying coupling cases, it is proved that if there exists T > 0 such that the union graph across any T-length time interval has cluster spanning trees and all graphs has all vertices self-linked, then the time-varying linear system can also realize intra-cluster synchronization. Under the assumption of common inter-cluster influence, a sort of inter-cluster nonidentical inputs are utilized to realize inter-cluster separation, such that each agent in the same cluster receives the same inputs and agents in different clusters have different inputs. In addition, the boundedness of the infinite sum of the inputs can guarantee the boundedness of the trajectory. As an application, we employ a modified non-Bayesian social learning model to illustrate the effectiveness of our results.

  18. A cluster randomized controlled trial of a clinical pathway for hospital treatment of heart failure: study design and population

    Directory of Open Access Journals (Sweden)

    Gardini Andrea

    2007-11-01

    Full Text Available Abstract Background The hospital treatment of heart failure frequently does not follow published guidelines, potentially contributing to the high morbidity, mortality and economic cost of this disorder. Consequently the development of clinical pathways has the potential to reduce the current variability in care, enhance guideline adherence, and improve outcomes for patients. Despite enthusiasm and diffusion, the widespread acceptance of clinical pathways remain questionable because very little prospective controlled data demonstrated their effectiveness. The Experimental Prospective Study on the Effectiveness and Efficiency of the Implementation of Clinical Pathways was designed in order to conduct a rigorous evaluation of clinical pathways in hospital treatment of acute heart failure. The primary objective of the trial was to evaluate the effectiveness of the implementation of clinical pathways for hospital treatment of heart failure in Italian hospitals. Methods/design Two-arm, cluster-randomized trial. 14 community hospitals were randomized either to arm 1 (clinical pathway: appropriate use of practice guidelines and supplies of drugs and ancillary services, new organization and procedures, patient education, etc. or to arm 2 (no intervention, usual care. 424 patients sample (212 in each group, 80% of power at the 5% significance level (two-sided. The primary outcome measure is in-hospital mortality. We will also analyze the impact of the clinical pathways comparing the length and the appropriateness of the stay, the rate of unscheduled readmissions, the customers' satisfaction and the costs treating the patients with the pathways and with the current practice along all the observation period. The quality of the care will be assessed by monitoring the use of diagnostic and therapeutic procedures during hospital stay and by measuring key quality indicators at discharge. Discussion This paper examines the design of the evaluation of a complex

  19. Cost-effectiveness of a long-term Internet-delivered worksite health promotion programme on physical activity and nutrition: A cluster randomized controlled trial

    NARCIS (Netherlands)

    S.J.W. Robroek (Suzan); S. Polinder (Suzanne); F.J. Bredt (Folef); A. Burdorf (Alex)

    2012-01-01

    textabstractThis study aims to evaluate the cost-effectiveness of a long-term workplace health promotion programme on physical activity (PA) and nutrition. In total, 924 participants enrolled in a 2-year cluster randomized controlled trial, with departments (n = 74) within companies (n = 6) as the

  20. Insights into an original pocket-ligand pair classification: a promising tool for ligand profile prediction.

    Directory of Open Access Journals (Sweden)

    Stéphanie Pérot

    Full Text Available Pockets are today at the cornerstones of modern drug discovery projects and at the crossroad of several research fields, from structural biology to mathematical modeling. Being able to predict if a small molecule could bind to one or more protein targets or if a protein could bind to some given ligands is very useful for drug discovery endeavors, anticipation of binding to off- and anti-targets. To date, several studies explore such questions from chemogenomic approach to reverse docking methods. Most of these studies have been performed either from the viewpoint of ligands or targets. However it seems valuable to use information from both ligands and target binding pockets. Hence, we present a multivariate approach relating ligand properties with protein pocket properties from the analysis of known ligand-protein interactions. We explored and optimized the pocket-ligand pair space by combining pocket and ligand descriptors using Principal Component Analysis and developed a classification engine on this paired space, revealing five main clusters of pocket-ligand pairs sharing specific and similar structural or physico-chemical properties. These pocket-ligand pair clusters highlight correspondences between pocket and ligand topological and physico-chemical properties and capture relevant information with respect to protein-ligand interactions. Based on these pocket-ligand correspondences, a protocol of prediction of clusters sharing similarity in terms of recognition characteristics is developed for a given pocket-ligand complex and gives high performances. It is then extended to cluster prediction for a given pocket in order to acquire knowledge about its expected ligand profile or to cluster prediction for a given ligand in order to acquire knowledge about its expected pocket profile. This prediction approach shows promising results and could contribute to predict some ligand properties critical for binding to a given pocket, and conversely

  1. Insights into an original pocket-ligand pair classification: a promising tool for ligand profile prediction.

    Science.gov (United States)

    Pérot, Stéphanie; Regad, Leslie; Reynès, Christelle; Spérandio, Olivier; Miteva, Maria A; Villoutreix, Bruno O; Camproux, Anne-Claude

    2013-01-01

    Pockets are today at the cornerstones of modern drug discovery projects and at the crossroad of several research fields, from structural biology to mathematical modeling. Being able to predict if a small molecule could bind to one or more protein targets or if a protein could bind to some given ligands is very useful for drug discovery endeavors, anticipation of binding to off- and anti-targets. To date, several studies explore such questions from chemogenomic approach to reverse docking methods. Most of these studies have been performed either from the viewpoint of ligands or targets. However it seems valuable to use information from both ligands and target binding pockets. Hence, we present a multivariate approach relating ligand properties with protein pocket properties from the analysis of known ligand-protein interactions. We explored and optimized the pocket-ligand pair space by combining pocket and ligand descriptors using Principal Component Analysis and developed a classification engine on this paired space, revealing five main clusters of pocket-ligand pairs sharing specific and similar structural or physico-chemical properties. These pocket-ligand pair clusters highlight correspondences between pocket and ligand topological and physico-chemical properties and capture relevant information with respect to protein-ligand interactions. Based on these pocket-ligand correspondences, a protocol of prediction of clusters sharing similarity in terms of recognition characteristics is developed for a given pocket-ligand complex and gives high performances. It is then extended to cluster prediction for a given pocket in order to acquire knowledge about its expected ligand profile or to cluster prediction for a given ligand in order to acquire knowledge about its expected pocket profile. This prediction approach shows promising results and could contribute to predict some ligand properties critical for binding to a given pocket, and conversely, some key pocket

  2. Morphological type correlation between nearest neighbor pairs of galaxies

    Science.gov (United States)

    Yamagata, Tomohiko

    1990-01-01

    Although the morphological type of galaxies is one of the most fundamental properties of galaxies, its origin and evolutionary processes, if any, are not yet fully understood. It has been established that the galaxy morphology strongly depends on the environment in which the galaxy resides (e.g., Dressler 1980). Galaxy pairs correspond to the smallest scales of galaxy clustering and may provide important clues to how the environment influences the formation and evolution of galaxies. Several investigators pointed out that there is a tendency for pair galaxies to have similar morphological types (Karachentsev and Karachentseva 1974, Page 1975, Noerdlinger 1979). Here, researchers analyze morphological type correlation for 18,364 nearest neighbor pairs of galaxies identified in the magnetic tape version of the Center for Astrophysics Redshift Catalogue.

  3. The effectiveness of community action in reducing risky alcohol consumption and harm: a cluster randomised controlled trial.

    Directory of Open Access Journals (Sweden)

    Anthony Shakeshaft

    2014-03-01

    Full Text Available The World Health Organization, governments, and communities agree that community action is likely to reduce risky alcohol consumption and harm. Despite this agreement, there is little rigorous evidence that community action is effective: of the six randomised trials of community action published to date, all were US-based and focused on young people (rather than the whole community, and their outcomes were limited to self-report or alcohol purchase attempts. The objective of this study was to conduct the first non-US randomised controlled trial (RCT of community action to quantify the effectiveness of this approach in reducing risky alcohol consumption and harms measured using both self-report and routinely collected data.We conducted a cluster RCT comprising 20 communities in Australia that had populations of 5,000-20,000, were at least 100 km from an urban centre (population ≥ 100,000, and were not involved in another community alcohol project. Communities were pair-matched, and one member of each pair was randomly allocated to the experimental group. Thirteen interventions were implemented in the experimental communities from 2005 to 2009: community engagement; general practitioner training in alcohol screening and brief intervention (SBI; feedback to key stakeholders; media campaign; workplace policies/practices training; school-based intervention; general practitioner feedback on their prescribing of alcohol medications; community pharmacy-based SBI; web-based SBI; Aboriginal Community Controlled Health Services support for SBI; Good Sports program for sports clubs; identifying and targeting high-risk weekends; and hospital emergency department-based SBI. Primary outcomes based on routinely collected data were alcohol-related crime, traffic crashes, and hospital inpatient admissions. Routinely collected data for the entire study period (2001-2009 were obtained in 2010. Secondary outcomes based on pre- and post-intervention surveys (n

  4. The effectiveness of community action in reducing risky alcohol consumption and harm: a cluster randomised controlled trial.

    Science.gov (United States)

    Shakeshaft, Anthony; Doran, Christopher; Petrie, Dennis; Breen, Courtney; Havard, Alys; Abudeen, Ansari; Harwood, Elissa; Clifford, Anton; D'Este, Catherine; Gilmour, Stuart; Sanson-Fisher, Rob

    2014-03-01

    The World Health Organization, governments, and communities agree that community action is likely to reduce risky alcohol consumption and harm. Despite this agreement, there is little rigorous evidence that community action is effective: of the six randomised trials of community action published to date, all were US-based and focused on young people (rather than the whole community), and their outcomes were limited to self-report or alcohol purchase attempts. The objective of this study was to conduct the first non-US randomised controlled trial (RCT) of community action to quantify the effectiveness of this approach in reducing risky alcohol consumption and harms measured using both self-report and routinely collected data. We conducted a cluster RCT comprising 20 communities in Australia that had populations of 5,000-20,000, were at least 100 km from an urban centre (population ≥ 100,000), and were not involved in another community alcohol project. Communities were pair-matched, and one member of each pair was randomly allocated to the experimental group. Thirteen interventions were implemented in the experimental communities from 2005 to 2009: community engagement; general practitioner training in alcohol screening and brief intervention (SBI); feedback to key stakeholders; media campaign; workplace policies/practices training; school-based intervention; general practitioner feedback on their prescribing of alcohol medications; community pharmacy-based SBI; web-based SBI; Aboriginal Community Controlled Health Services support for SBI; Good Sports program for sports clubs; identifying and targeting high-risk weekends; and hospital emergency department-based SBI. Primary outcomes based on routinely collected data were alcohol-related crime, traffic crashes, and hospital inpatient admissions. Routinely collected data for the entire study period (2001-2009) were obtained in 2010. Secondary outcomes based on pre- and post-intervention surveys (n = 2,977 and 2

  5. Cluster ensembles, quantization and the dilogarithm

    DEFF Research Database (Denmark)

    Fock, Vladimir; Goncharov, Alexander B.

    2009-01-01

    A cluster ensemble is a pair of positive spaces (i.e. varieties equipped with positive atlases), coming with an action of a symmetry group . The space is closely related to the spectrum of a cluster algebra [ 12 ]. The two spaces are related by a morphism . The space is equipped with a closed -form......, possibly degenerate, and the space has a Poisson structure. The map is compatible with these structures. The dilogarithm together with its motivic and quantum avatars plays a central role in the cluster ensemble structure. We define a non-commutative -deformation of the -space. When is a root of unity...

  6. Scattering of electrons in copper by a Frenkel pair defect

    Energy Technology Data Exchange (ETDEWEB)

    Lodder, A.; Rijsdijk, G.A.; Bukman, D.J.; Baratta, A.J.; Molenaar, J.

    1988-06-01

    The Korringa-Kohn-Rostoker (KKR) Green function extended-defect formalism, used to describe the scattering of Bloch electrons in a dilute alloy, is generalised to include an asymmetric defect centred on a lattice site. The revised theory is then used to investigate conduction electron scattering from Frenkel pairs in Cu. Such defects consist of two self-interstitial atoms centred on a vacant lattice site forming a dumb-bell oriented along the <100> axis. The generalised formalism allows one to calculate the cluster t matrix T for the Frenkel pair cluster including the surrounding displaced nearest neighbours. It was found that the interstitials at the vacant lattice site could still be treated within the muffin-tin potential as a central scatterer characterised by a t matrix which is non-diagonal in the angular momentum. Electron scattering rates and Dingle temperatures are calculated and discussed in view of preliminary experimental results.

  7. Scattering of electrons in copper by a Frenkel pair defect

    International Nuclear Information System (INIS)

    Lodder, A.; Rijsdijk, G.A.; Bukman, D.J.; Baratta, A.J.; Molenaar, J.

    1988-01-01

    The Korringa-Kohn-Rostoker (KKR) Green function extended-defect formalism, used to describe the scattering of Bloch electrons in a dilute alloy, is generalised to include an asymmetric defect centred on a lattice site. The revised theory is then used to investigate conduction electron scattering from Frenkel pairs in Cu. Such defects consist of two self-interstitial atoms centred on a vacant lattice site forming a dumb-bell oriented along the axis. The generalised formalism allows one to calculate the cluster t matrix T for the Frenkel pair cluster including the surrounding displaced nearest neighbours. It was found that the interstitials at the vacant lattice site could still be treated within the muffin-tin potential as a central scatterer characterised by a t matrix which is non-diagonal in the angular momentum. Electron scattering rates and Dingle temperatures are calculated and discussed in view of preliminary experimental results. (author)

  8. Effects of a multi-faceted program to increase influenza vaccine uptake among health care workers in nursing homes : A cluster randomised controlled trial

    NARCIS (Netherlands)

    Looijmans-van den Akker, I.; van Delden, J.J.M.; Verheij, T.J.M.; van der Sande, M.A.B.; van Essen, G.A.; Riphagen-Dalhuisen, J.; Hulscher, M.E.; Hak, E.

    2010-01-01

    Despite the recommendation of the Dutch association of nursing home physicians (NVVA) to be immunized against influenza, vaccine uptake among HCWs in nursing homes remains unacceptably low. Therefore we conducted a cluster randomised controlled trial among 33 Dutch nursing homes to assess the

  9. Effectiveness of a selective intervention program targeting personality risk factors for alcohol misuse among young adolescents: results of a cluster randomized controlled trial

    NARCIS (Netherlands)

    Lammers, J.; Goossens, F.; Conrod, P.; Engels, R.C.M.E.; Wiers, R.W.H.J.; Kleinjan, M.

    2015-01-01

    Aim The effectiveness of Preventure was tested on drinking behaviour of young adolescents in secondary education in the Netherlands. Design A cluster randomized controlled trial was carried out, with participants assigned randomly to a two-session coping skills intervention or a control

  10. Behavioural graded activity results in better exercise adherence and more physical activity than usual care in people with osteoarthritis: a cluster-randomised trial

    NARCIS (Netherlands)

    Pisters, M.F.; Veenhof, C.; de Bakker, D.H.; Schellevis, F.G.; Dekker, J.

    2010-01-01

    Question: Does behavioural graded activity result in better exercise adherence and more physical activity than usual care in people with osteoarthritis of the hip or knee? Design: Analysis of secondary outcomes of a cluster-randomised trial with concealed allocation, assessor blinding, and

  11. Involving patients in setting priorities for healthcare improvement: a cluster randomized trial.

    Science.gov (United States)

    Boivin, Antoine; Lehoux, Pascale; Lacombe, Réal; Burgers, Jako; Grol, Richard

    2014-02-20

    Patients are increasingly seen as active partners in healthcare. While patient involvement in individual clinical decisions has been extensively studied, no trial has assessed how patients can effectively be involved in collective healthcare decisions affecting the population. The goal of this study was to test the impact of involving patients in setting healthcare improvement priorities for chronic care at the community level. Cluster randomized controlled trial. Local communities were randomized in intervention (priority setting with patient involvement) and control sites (no patient involvement). Communities in a canadian region were required to set priorities for improving chronic disease management in primary care, from a list of 37 validated quality indicators. Patients were consulted in writing, before participating in face-to-face deliberation with professionals. Professionals established priorities among themselves, without patient involvement. A total of 172 individuals from six communities participated in the study, including 83 chronic disease patients, and 89 health professionals. The primary outcome was the level of agreement between patients' and professionals' priorities. Secondary outcomes included professionals' intention to use the selected quality indicators, and the costs of patient involvement. Priorities established with patients were more aligned with core generic components of the Medical Home and Chronic Care Model, including: access to primary care, self-care support, patient participation in clinical decisions, and partnership with community organizations (p Priorities established by professionals alone placed more emphasis on the technical quality of single disease management. The involvement intervention fostered mutual influence between patients and professionals, which resulted in a 41% increase in agreement on common priorities (95%CI: +12% to +58%, p priorities. Patient involvement can change priorities driving healthcare

  12. A Cluster-Randomised Trial of Staff Education to Improve the Quality of Life of People with Dementia Living in Residential Care: The DIRECT Study

    OpenAIRE

    Beer, Christopher; Horner, Barbara; Flicker, Leon; Scherer, Samuel; Lautenschlager, Nicola T.; Bretland, Nick; Flett, Penelope; Schaper, Frank; Almeida, Osvaldo P.

    2011-01-01

    BACKGROUND: The Dementia In Residential care: EduCation intervention Trial (DIRECT) was conducted to determine if delivery of education designed to meet the perceived need of GPs and care staff improves the quality of life of participants with dementia living in residential care. METHODOLOGY/PRINCIPAL FINDINGS: This cluster-randomised controlled trial was conducted in 39 residential aged care facilities in the metropolitan area of Perth, Western Australia. 351 care facility residents aged 65 ...

  13. Silence is deadly: a cluster-randomised controlled trial of a mental health help-seeking intervention for young men

    Directory of Open Access Journals (Sweden)

    Alison L. Calear

    2017-10-01

    Full Text Available Abstract Background Young men are consistently less likely to seek help for mental health problems than their female peers. This is particularly concerning given the high rates of suicide among male adolescents. The school system has been identified as an ideal setting for the implementation of prevention and early intervention programs for young people. The current trial aims to determine the effectiveness of the Silence is Deadly program in increasing positive help-seeking intentions for mental health problems and suicide among male secondary school students. Methods This study is a two-arm, cluster-randomised, controlled trial that will compare the Silence is Deadly program to a wait-list control condition. Eight Australian high schools will be recruited to the trial, with male students in grades 11 and 12 (16 to 18 years of age targeted for participation. The program is an innovative male-tailored suicide prevention intervention, comprising a presentation that emphasises role-modelling and legitimises help-seeking for personal and emotional problems, and a brief video that features celebrity athletes who counter existing male norms around help-seeking and encourage communication about personal and emotional issues. The program also includes a discussion of how to help a friend in distress and ends with a question and answer session. The primary outcome measure for the current study is help-seeking intentions. Secondary outcomes include help-seeking behaviour, help-seeking attitudes, help-seeking stigma, mental health symptoms, and suicidal ideation. Data will be collected pre-intervention, post-intervention, and at 3-month follow-up. Primary analyses will compare changes in help-seeking intentions for the intervention condition relative to the wait-list control condition using mixed-effects repeated-measures analyses that account for clustering within schools. Discussion If proven to be effective, this targeted help-seeking intervention for

  14. Tiling array-CGH for the assessment of genomic similarities among synchronous unilateral and bilateral invasive breast cancer tumor pairs

    Directory of Open Access Journals (Sweden)

    Ringnér Markus

    2008-07-01

    Full Text Available Abstract Background Today, no objective criteria exist to differentiate between individual primary tumors and intra- or intermammary dissemination respectively, in patients diagnosed with two or more synchronous breast cancers. To elucidate whether these tumors most likely arise through clonal expansion, or whether they represent individual primary tumors is of tumor biological interest and may have clinical implications. In this respect, high resolution genomic profiling may provide a more reliable approach than conventional histopathological and tumor biological factors. Methods 32 K tiling microarray-based comparative genomic hybridization (aCGH was used to explore the genomic similarities among synchronous unilateral and bilateral invasive breast cancer tumor pairs, and was compared with histopathological and tumor biological parameters. Results Based on global copy number profiles and unsupervised hierarchical clustering, five of ten (p = 1.9 × 10-5 unilateral tumor pairs displayed similar genomic profiles within the pair, while only one of eight bilateral tumor pairs (p = 0.29 displayed pair-wise genomic similarities. DNA index, histological type and presence of vessel invasion correlated with the genomic analyses. Conclusion Synchronous unilateral tumor pairs are often genomically similar, while synchronous bilateral tumors most often represent individual primary tumors. However, two independent unilateral primary tumors can develop synchronously and contralateral tumor spread can occur. The presence of an intraductal component is not informative when establishing the independence of two tumors, while vessel invasion, the presence of which was found in clustering tumor pairs but not in tumor pairs that did not cluster together, supports the clustering outcome. Our data suggest that genomically similar unilateral tumor pairs may represent a more aggressive disease that requires the addition of more severe treatment modalities, and

  15. Effect of provision of daily zinc and iron with several micronutrients on growth and morbidity among young children in Pakistan: A cluster-randomised trial

    International Nuclear Information System (INIS)

    Soofi, Sajid

    2014-01-01

    Full text: Background: Powders containing iron and other micronutrients are recommended as a strategy to prevent nutritional anaemia and other micronutrient deficiencies in children. We assessed the effects of provision of two micronutrient powder formulations, with or without zinc, to children in Pakistan. Methods: We did a cluster randomised trial in urban and rural sites in Sindh, Pakistan. A baseline survey identified 256 clusters, which were randomly assigned (within urban and rural strata, by computer-generated random numbers) to one of three groups: non-supplemented control (group A), micronutrient powder without zinc (group B), or micronutrient powder with 10 mg zinc (group C). Children in the clusters aged 6 months were eligible for inclusion in the study. Powders were to be given daily between 6 and 18 months of age; follow-up was to age 2 years. Micronutrient powder sachets for groups B and C were identical except for colour; investigators and field and supervisory staff were masked to composition of the micronutrient powders until trial completion. Parents knew whether their child was receiving supplementation, but did not know whether the powder contained zinc. Primary outcomes were growth, episodes of diarrhoea, acute lower respiratory tract infection, fever, and incidence of admission to hospital. This trial is registered with ClinicalTrials.gov, number NCT00705445. Results: The trial was done between Nov 1, 2008, and Dec 31, 2011. 947 children were enrolled in group A clusters, 910 in group B clusters, and 889 in group C clusters. Micronutrient powder administration was associated with lower risk of iron-deficiency anaemia at 18 months compared with the control group (odds ratio [OR] for micronutrient powder without zinc = 0•20, 95% CI 0•11–0•36; OR for micronutrient powder with zinc = 0•25, 95% CI 0•14–0•44). Compared with the control group, children in the group receiving micronutrient powder without zinc gained an extra 0•31 cm

  16. Calculation of resonance integral for fuel cluster

    International Nuclear Information System (INIS)

    Remsak, S.

    1969-01-01

    The procedure for calculating the shielding correction, formulated in the previous paper [6], was broadened and applied for a cluster of cylindrical rods. The sam analytical method as in the previous paper was applied. A combination of Gauss method with the method of Almgren and Porn used for solving the same type of integral was used to calculate the geometry functions. CLUSTER code was written for ZUSE-Z-23 computer to calculate the shielding corrections for pairs of fuel rods in the cluster. Computing time for one pair of fuel rods depends on the number of closely placed rod, and for two closely placed rods it is about 3 hours. Calculations were done for clusters containing 7 and 19 UO 2 rods. results show that calculated values of resonance integrals are somewhat higher than the values obtained by Helstrand empirical formula. Taking into account the results for two rods from the previous paper it can be noted that the calculated and empirical values for clusters with 2 and 7 rods are in agreement since the deviations do not exceed the limits of experimental error (±2%). In case of larger cluster with 19 rods deviations are higher than the experimental error. Most probably the calculated values exceed the experimental ones result from the fact that in this paper the shielding correction is calculated only in the region up to 1 keV [sr

  17. Description of an α-cluster tail in 8Be and 20Ne: Delocalization of the α cluster by quantum penetration

    Science.gov (United States)

    Kanada-En'yo, Yoshiko

    2014-10-01

    We analyze the α-cluster wave functions in cluster states of ^8Be and ^{20}Ne by comparing the exact relative wave function obtained by the generator coordinate method (GCM) with various types of trial functions. For the trial functions, we adopt the fixed range shifted Gaussian of the Brink-Bloch (BB) wave function, the spherical Gaussian with the adjustable range parameter of the spherical Tohsaki-Horiuchi-Schuck-Röpke (sTHSR), the deformed Gaussian of the deformed THSR (dTHSR), and a function with the Yukawa tail (YT). The quality of the description of the exact wave function with a trial function is judged by the squared overlap between the trial function and the GCM wave function. A better result is obtained with the sTHSR wave function than the BB wave function, and further improvement can be made with the dTHSR wave function because these wave functions can describe the outer tail better. The YT wave function gives almost an equal quality to or even better quality than the dTHSR wave function, indicating that the outer tail of α-cluster states is characterized by the Yukawa-like tail rather than the Gaussian tail. In weakly bound α-cluster states with small α separation energy and the low centrifugal and Coulomb barriers, the outer tail part is the slowly damping function described well by the quantum penetration through the effective barrier. This outer tail characterizes the almost zero-energy free α gas behavior, i.e., the delocalization of the cluster.

  18. Study protocol: cost-effectiveness of multidisciplinary nutritional support for undernutrition in older adults in nursing home and home-care: cluster randomized controlled trial

    DEFF Research Database (Denmark)

    Beck, Anne Marie; Gøgsig Christensen, Annette; Stenbæk Hansen, Birthe

    2014-01-01

    BACKGROUND: Older adults in nursing home and home-care are a particularly high-risk population for weight loss or poor nutrition. One negative consequence of undernutrition is increased health care costs. Several potentially modifiable nutritional risk factors increase the likelihood of weight loss......-effectiveness of nutritional support among undernourished older adults and none of these have used such a multidisciplinary approach. METHODS: An 11 week cluster randomized trial to assess the cost-effectiveness of multidisciplinary nutritional support for undernutrition in older adults in nursing home and home...... older adults in home-care and nursing home and contribute to important research. TRIAL REGISTRATION: ClinicalTrials.gov 2013 NCT01873456....

  19. The Effects of Therapist Competence in Assigning Homework in Cognitive Therapy with Cluster C Personality Disorders: Results from a Randomized Controlled Trial

    Science.gov (United States)

    Ryum, Truls; Stiles, Tore C.; Svartberg, Martin; McCullough, Leigh

    2010-01-01

    Therapist competence in assigning homework was used to predict mid- and posttreatment outcome for patients with Cluster C personality disorders in cognitive therapy (CT). Twenty-five patients that underwent 40 sessions of CT were taken from a randomized controlled trial (Svartberg, Stiles, & Seltzer, 2004). Therapist competence in assigning…

  20. The Diabetes Remission Clinical Trial (DiRECT): protocol for a cluster randomised trial.

    Science.gov (United States)

    Leslie, Wilma S; Ford, Ian; Sattar, Naveed; Hollingsworth, Kieren G; Adamson, Ashley; Sniehotta, Falko F; McCombie, Louise; Brosnahan, Naomi; Ross, Hazel; Mathers, John C; Peters, Carl; Thom, George; Barnes, Alison; Kean, Sharon; McIlvenna, Yvonne; Rodrigues, Angela; Rehackova, Lucia; Zhyzhneuskaya, Sviatlana; Taylor, Roy; Lean, Mike E J

    2016-02-16

    Despite improving evidence-based practice following clinical guidelines to optimise drug therapy, Type 2 diabetes (T2DM) still exerts a devastating toll from vascular complications and premature death. Biochemical remission of T2DM has been demonstrated with weight loss around 15kg following bariatric surgery and in several small studies of non-surgical energy-restriction treatments. The non-surgical Counterweight-Plus programme, running in Primary Care where obesity and T2DM are routinely managed, produces >15 kg weight loss in 33% of all enrolled patients. The Diabetes UK-funded Counterpoint study suggested that this should be sufficient to reverse T2DM by removing ectopic fat in liver and pancreas, restoring first-phase insulin secretion. The Diabetes Remission Clinical Trial (DiRECT) was designed to determine whether a structured, intensive, weight management programme, delivered in a routine Primary Care setting, is a viable treatment for achieving durable normoglycaemia. Other aims are to understand the mechanistic basis of remission and to identify psychological predictors of response. Cluster-randomised design with GP practice as the unit of randomisation: 280 participants from around 30 practices in Scotland and England will be allocated either to continue usual guideline-based care or to add the Counterweight-Plus weight management programme, which includes primary care nurse or dietitian delivery of 12-20weeks low calorie diet replacement, food reintroduction, and long-term weight loss maintenance. Main inclusion criteria: men and women aged 20-65 years, all ethnicities, T2DM 0-6years duration, BMI 27-45 kg/m(2). Tyneside participants will undergo Magnetic Resonance (MR) studies of pancreatic and hepatic fat, and metabolic studies to determine mechanisms underlying T2DM remission. Co-primary endpoints: weight reduction ≥ 15 kg and HbA1c <48 mmol/mol at one year. Further follow-up at 2 years. This study will establish whether a structured weight

  1. Six-monthly vitamin A from 1 to 6 years of age DEVTA: cluster ...

    Indian Academy of Sciences (India)

    Six-monthly vitamin A from 1 to 6 years of age DEVTA: cluster-randomised trial in 1 million children in Northern India · Pre-school rural Northern India · DEVTA: cluster-randomised trial in 8000+ villages (ie, AWCs) in 72 clusters (ie, blocks) · DEVTA vitamin A schedule, 05/1999 - 04/2004 · DEVTA: biomedical monitoring.

  2. Use of malaria rapid diagnostic tests by community health workers in Afghanistan: cluster randomised trial.

    Science.gov (United States)

    Leslie, Toby; Rowland, Mark; Mikhail, Amy; Cundill, Bonnie; Willey, Barbara; Alokozai, Asif; Mayan, Ismail; Hasanzai, Anwar; Baktash, Sayed Habibullah; Mohammed, Nader; Wood, Molly; Rahimi, Habib-U-Rahman; Laurent, Baptiste; Buhler, Cyril; Whitty, Christopher J M

    2017-07-07

    The World Health Organisation (WHO) recommends parasitological diagnosis of malaria before treatment, but use of malaria rapid diagnostic tests (mRDTs) by community health workers (CHWs) has not been fully tested within health services in south and central Asia. mRDTs could allow CHWs to diagnose malaria accurately, improving treatment of febrile illness. A cluster randomised trial in community health services was undertaken in Afghanistan. The primary outcome was the proportion of suspected malaria cases correctly treated for polymerase chain reaction (PCR)-confirmed malaria and PCR negative cases receiving no antimalarial drugs measured at the level of the patient. CHWs from 22 clusters (clinics) received standard training on clinical diagnosis and treatment of malaria; 11 clusters randomised to the intervention arm received additional training and were provided with mRDTs. CHWs enrolled cases of suspected malaria, and the mRDT results and treatments were compared to blind-read PCR diagnosis. In total, 256 CHWs enrolled 2400 patients with 2154 (89.8%) evaluated. In the intervention arm, 75.3% (828/1099) were treated appropriately vs. 17.5% (185/1055) in the control arm (cluster adjusted risk ratio: 3.72, 95% confidence interval 2.40-5.77; p < 0.001). In the control arm, 85.9% (164/191) with confirmed Plasmodium vivax received chloroquine compared to 45.1% (70/155) in the intervention arm (p < 0.001). Overuse of chloroquine in the control arm resulted in 87.6% (813/928) of those with no malaria (PCR negative) being treated vs. 10.0% (95/947) in the intervention arm, p < 0.001. In the intervention arm, 71.4% (30/42) of patients with P. falciparum did not receive artemisinin-based combination therapy, partly because operational sensitivity of the RDTs was low (53.2%, 38.1-67.9). There was high concordance between recorded RDT result and CHW prescription decisions: 826/950 (87.0%) with a negative test were not prescribed an antimalarial. Co

  3. The cost-effectiveness of a patient centred pressure ulcer prevention care bundle: Findings from the INTACT cluster randomised trial.

    OpenAIRE

    Whitty, Jennifer A; McInnes, Elizabeth; Bucknall, Tracey; Webster, Joan; Gillespie, Brigid M; Banks, Merrilyn; Thalib, Lukman; Wallis, Marianne; Cumsille, Jose; Roberts, Shelley; Chaboyer, Wendy

    2017-01-01

    Pressure ulcers are serious, avoidable, costly and common adverse outcomes of healthcare. To evaluate the cost-effectiveness of a patient-centred pressure ulcer prevention care bundle compared to standard care. Cost-effectiveness and cost-benefit analyses of pressure ulcer prevention performed from the health system perspective using data collected alongside a cluster-randomised trial. Eight tertiary hospitals in Australia. Adult patients receiving either a patient-centred pressure ulcer prev...

  4. Effectiveness of a group diabetes education programme in underserved communities in South Africa: pragmatic cluster randomized control trial

    Directory of Open Access Journals (Sweden)

    Mash Bob

    2012-12-01

    Full Text Available Abstract Background Diabetes is an important contributor to the burden of disease in South Africa and prevalence rates as high as 33% have been recorded in Cape Town. Previous studies show that quality of care and health outcomes are poor. The development of an effective education programme should impact on self-care, lifestyle change and adherence to medication; and lead to better control of diabetes, fewer complications and better quality of life. Methods Trial design: Pragmatic cluster randomized controlled trial Participants: Type 2 diabetic patients attending 45 public sector community health centres in Cape Town Interventions: The intervention group will receive 4 sessions of group diabetes education delivered by a health promotion officer in a guiding style. The control group will receive usual care which consists of ad hoc advice during consultations and occasional educational talks in the waiting room. Objective: To evaluate the effectiveness of the group diabetes education programme Outcomes: Primary outcomes: diabetes self-care activities, 5% weight loss, 1% reduction in HbA1c. Secondary outcomes: self-efficacy, locus of control, mean blood pressure, mean weight loss, mean waist circumference, mean HbA1c, mean total cholesterol, quality of life Randomisation: Computer generated random numbers Blinding: Patients, health promoters and research assistants could not be blinded to the health centre’s allocation Numbers randomized: Seventeen health centres (34 in total will be randomly assigned to either control or intervention groups. A sample size of 1360 patients in 34 clusters of 40 patients will give a power of 80% to detect the primary outcomes with 5% precision. Altogether 720 patients were recruited in the intervention arm and 850 in the control arm giving a total of 1570. Discussion The study will inform policy makers and managers of the district health system, particularly in low to middle income countries, if this programme can

  5. A National Quality Improvement Collaborative for the clinical use of outcome measurement in specialised mental healthcare: results from a parallel group design and a nested cluster randomised controlled trial.

    Science.gov (United States)

    Metz, Margot J; Veerbeek, Marjolein A; Franx, Gerdien C; van der Feltz-Cornelis, Christina M; de Beurs, Edwin; Beekman, Aartjan T F

    2017-05-01

    Although the importance and advantages of measurement-based care in mental healthcare are well established, implementation in daily practice is complex and far from optimal. To accelerate the implementation of outcome measurement in routine clinical practice, a government-sponsored National Quality Improvement Collaborative was initiated in Dutch-specialised mental healthcare. To investigate the effects of this initiative, we combined a matched-pair parallel group design (21 teams) with a cluster randomised controlled trial (RCT) (6 teams). At the beginning and end, the primary outcome 'actual use and perceived clinical utility of outcome measurement' was assessed. In both designs, intervention teams demonstrated a significant higher level of implementation of outcome measurement than control teams. Overall effects were large (parallel group d =0.99; RCT d =1.25). The National Collaborative successfully improved the use of outcome measurement in routine clinical practice. None. © The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license.

  6. Patients’ general satisfaction with telephone counseling by pharmacists and effects on satisfaction with information and beliefs about medicines: results from a cluster randomized trial.

    NARCIS (Netherlands)

    Kooy, M.J.; Geffen, E.C.G. van; Heerdink, E.R.; Dijk, L. van; Bouvy, M.L.

    2015-01-01

    Objective: Assess effects of pharmacists’ counseling by telephone on patients’ satisfaction with counseling, satisfaction with information and beliefs about medicines for newly prescribed medicines. Methods: A cluster randomized trial in Dutch community pharmacies. Patients ≥18 years were included

  7. Patients' general satisfaction with telephone counseling by pharmacists and effects on satisfaction with information and beliefs about medicines : Results from a cluster randomized trial

    NARCIS (Netherlands)

    Kooy, Marcel Jan; Van Geffen, Erica C G; Heerdink, Eibert R.; Van Dijk, Liset; Bouvy, Marcel L.

    2015-01-01

    Assess effects of pharmacists' counseling by telephone on patients' satisfaction with counseling, satisfaction with information and beliefs about medicines for newly prescribed medicines. Methods: A cluster randomized trial in Dutch community pharmacies. Patients ≥18 years were included when

  8. Cost-Effectiveness of a Chronic Care Model for Frail Older Adults in Primary Care: Economic Evaluation Alongside a Stepped-Wedge Cluster-Randomized Trial

    NARCIS (Netherlands)

    van Leeuwen, K.M.; Bosmans, J.E.; Jansen, A.P.D.; Hoogendijk, E.O.; Muntinga, M.E.; van Hout, H.P.J.; Nijpels, G.; van der Horst, H.E.; van Tulder, M.W.

    2015-01-01

    Objectives To evaluate the cost-effectiveness of the Geriatric Care Model (GCM), an integrated care model for frail older adults based on the Chronic Care Model, with that of usual care. Design Economic evaluation alongside a 24-month stepped-wedge cluster-randomized controlled trial. Setting

  9. Cost-Effectiveness of a Chronic Care Model for Frail Older Adults in Primary Care : Economic Evaluation Alongside a Stepped-Wedge Cluster-Randomized Trial

    NARCIS (Netherlands)

    van Leeuwen, Karen M; Bosmans, Judith E; Jansen, Aaltje P D; Hoogendijk, Emiel O; Muntinga, Maaike E; van Hout, Hein P J; Nijpels, Giel; van der Horst, Henriette E; van Tulder, Maurits W

    2015-01-01

    OBJECTIVES: To evaluate the cost-effectiveness of the Geriatric Care Model (GCM), an integrated care model for frail older adults based on the Chronic Care Model, with that of usual care. DESIGN: Economic evaluation alongside a 24-month stepped-wedge cluster-randomized controlled trial. SETTING:

  10. Efficacy of a workplace osteoporosis prevention intervention: a cluster randomized trial.

    Science.gov (United States)

    Tan, Ai May; LaMontagne, Anthony D; English, Dallas R; Howard, Peter

    2016-08-24

    Osteoporosis is a debilitating disease. Adequate calcium consumption and physical activity are the two major modifiable risk factors. This paper describes the major outcomes and efficacy of a workplace-based targeted behaviour change intervention to improve the dietary and physical activity behaviours of working women in sedentary occupations in Singapore. A cluster-randomized design was used, comparing the efficacy of a tailored intervention to standard care. Workplaces were the units of randomization and intervention. Sixteen workplaces were recruited from a pool of 97, and randomly assigned to intervention and control arms (eight workplaces in each). Women meeting specified inclusion criteria were then recruited to participate. Workplaces in the intervention arm received three participatory workshops and organization-wide educational activities. Workplaces in the control/standard care arm received print resources. Outcome measures were calcium intake (milligrams/day) and physical activity level (duration: minutes/week), measured at baseline, 4 weeks and 6 months post intervention. Adjusted cluster-level analyses were conducted comparing changes in intervention versus control groups, following intention-to-treat principles and CONSORT guidelines. Workplaces in the intervention group reported a significantly greater increase in calcium intake and duration of load-bearing moderate to vigorous physical activity (MVPA) compared with the standard care control group. Four weeks after intervention, the difference in adjusted mean calcium intake was 343.2 mg/day (95 % CI = 337.4 to 349.0, p workplace-based intervention substantially improved calcium intake and load-bearing moderate to vigorous physical activity 6 months after the intervention began. Australia New Zealand Clinical Trial Registry ACTRN12616000079448 . Registered 25 January 2016 (retrospectively registered).

  11. Walking Away from Type 2 diabetes: a cluster randomized controlled trial.

    Science.gov (United States)

    Yates, T; Edwardson, C L; Henson, J; Gray, L J; Ashra, N B; Troughton, J; Khunti, K; Davies, M J

    2017-05-01

    This study aimed to investigate whether an established behavioural intervention, Walking Away from Type 2 Diabetes, is effective at promoting and sustaining increased walking activity when delivered within primary care. Cluster randomized controlled trial involving 10 general practices recruited from Leicestershire, UK, in 2009-2010. Eight hundred and eight (36% female) individuals with a high risk of Type 2 diabetes mellitus, identified through a validated risk score, were included. Participants in five practices were randomized to Walking Away from Type 2 Diabetes, a pragmatic 3-h group-based structured education programme incorporating pedometer use with annual follow-on refresher sessions. The primary outcome was accelerometer assessed ambulatory activity (steps/day) at 12 months. Longer term maintenance was assessed at 24 and 36 months. Results were analysed using generalized estimating equation models, accounting for clustering. Complete accelerometer data for the primary outcome were available for 571 (71%) participants. Increases in ambulatory activity of 411 steps/day [95% confidence interval (CI): 117, 704] and self-reported vigorous-intensity physical activity of 218 metabolic equivalent min/week (95% CI: 6, 425) at 12 months were observed in the intervention group compared with control; differences between groups were not sustained at 36 months. No differences between groups were observed for markers of cardiometabolic health. Replacing missing data with multiple imputation did not affect the results. A pragmatic low-resource group-based structured education programme with pedometer use resulted in modest increases in ambulatory activity compared with control conditions after 12 months when implemented within a primary care setting to those at high risk of Type 2 diabetes mellitus; however, the results were not maintained over 36 months. © 2016 Diabetes UK.

  12. Improving local clustering based top-L link prediction methods via asymmetric link clustering information

    Science.gov (United States)

    Wu, Zhihao; Lin, Youfang; Zhao, Yiji; Yan, Hongyan

    2018-02-01

    Networks can represent a wide range of complex systems, such as social, biological and technological systems. Link prediction is one of the most important problems in network analysis, and has attracted much research interest recently. Many link prediction methods have been proposed to solve this problem with various techniques. We can note that clustering information plays an important role in solving the link prediction problem. In previous literatures, we find node clustering coefficient appears frequently in many link prediction methods. However, node clustering coefficient is limited to describe the role of a common-neighbor in different local networks, because it cannot distinguish different clustering abilities of a node to different node pairs. In this paper, we shift our focus from nodes to links, and propose the concept of asymmetric link clustering (ALC) coefficient. Further, we improve three node clustering based link prediction methods via the concept of ALC. The experimental results demonstrate that ALC-based methods outperform node clustering based methods, especially achieving remarkable improvements on food web, hamster friendship and Internet networks. Besides, comparing with other methods, the performance of ALC-based methods are very stable in both globalized and personalized top-L link prediction tasks.

  13. Effect of a nutrition supplement and physical activity program on pneumonia and walking capacity in Chilean older people: a factorial cluster randomized trial.

    Directory of Open Access Journals (Sweden)

    Alan D Dangour

    2011-04-01

    Full Text Available Ageing is associated with increased risk of poor health and functional decline. Uncertainties about the health-related benefits of nutrition and physical activity for older people have precluded their widespread implementation. We investigated the effectiveness and cost-effectiveness of a national nutritional supplementation program and/or a physical activity intervention among older people in Chile.We conducted a cluster randomized factorial trial among low to middle socioeconomic status adults aged 65-67.9 years living in Santiago, Chile. We randomized 28 clusters (health centers into the study and recruited 2,799 individuals in 2005 (~100 per cluster. The interventions were a daily micronutrient-rich nutritional supplement, or two 1-hour physical activity classes per week, or both interventions, or neither, for 24 months. The primary outcomes, assessed blind to allocation, were incidence of pneumonia over 24 months, and physical function assessed by walking capacity 24 months after enrollment. Adherence was good for the nutritional supplement (~75%, and moderate for the physical activity intervention (~43%. Over 24 months the incidence rate of pneumonia did not differ between intervention and control clusters (32.5 versus 32.6 per 1,000 person years respectively; risk ratio = 1.00; 95% confidence interval 0.61-1.63; p = 0.99. In intention-to-treat analysis, after 24 months there was a significant difference in walking capacity between the intervention and control clusters (mean difference 33.8 meters; 95% confidence interval 13.9-53.8; p = 0.001. The overall cost of the physical activity intervention over 24 months was US$164/participant; equivalent to US$4.84/extra meter walked. The number of falls and fractures was balanced across physical activity intervention arms and no serious adverse events were reported for either intervention.Chile's nutritional supplementation program for older people is not effective in reducing the

  14. Update to a protocol for a feasibility cluster randomised controlled trial of a peer-led school-based intervention to increase the physical activity of adolescent girls (PLAN-A).

    Science.gov (United States)

    Sebire, Simon J; Edwards, Mark J; Campbell, Rona; Jago, Russell; Kipping, Ruth; Banfield, Kathryn; Kadir, Bryar; Garfield, Kirsty; Lyons, Ronan A; Blair, Peter S; Hollingworth, William

    2016-01-01

    Physical activity levels are low amongst adolescent girls, and this population faces specific barriers to being active. Peer influences on health behaviours are important in adolescence, and peer-led interventions might hold promise to change behaviour. This paper describes the protocol for a feasibility cluster randomised controlled trial of Peer-Led physical Activity iNtervention for Adolescent girls (PLAN-A), a peer-led intervention aimed at increasing adolescent girls' physical activity levels. In addition, this paper describes an update that has been made to the protocol for the PLAN-A feasibility cluster randomised controlled trial. A two-arm cluster randomised feasibility trial will be conducted in six secondary schools (intervention n  = 4; control n  = 2) with year 8 (12-13 years old) girls. The intervention will operate at a year group level and consist of year 8 girls nominating influential peers within their year group to become peer supporters. Approximately 15% of the cohort will receive 3 days of training about physical activity and interpersonal communication skills. Peer supporters will then informally diffuse messages about physical activity amongst their friends for 10 weeks. Data will be collected at baseline (time 0 (T0)), immediately after the intervention (time 1 (T1)) and 12 months after baseline measures (time 2 (T2)). In this feasibility trial, the primary interest is in the recruitment of schools and participants (both year 8 girls and peer supporters), delivery and receipt of the intervention, data provision rates and identifying the cost categories for future economic analysis. Physical activity will be assessed using 7-day accelerometry, with the likely primary outcome in a fully powered trial being daily minutes of moderate-to-vigorous physical activity. Participants will also complete psychosocial questionnaires at each time point: assessing motivation, self-esteem and peer physical activity norms. Data analysis will be

  15. The extended Infant Feeding, Activity and Nutrition Trial (InFANT Extend Program: a cluster-randomized controlled trial of an early intervention to prevent childhood obesity

    Directory of Open Access Journals (Sweden)

    Karen J. Campbell

    2016-02-01

    Full Text Available Abstract Background Understanding how we can prevent childhood obesity in scalable and sustainable ways is imperative. Early RCT interventions focused on the first two years of life have shown promise however, differences in Body Mass Index between intervention and control groups diminish once the interventions cease. Innovative and cost-effective strategies seeking to continue to support parents to engender appropriate energy balance behaviours in young children need to be explored. Methods/Design The Infant Feeding Activity and Nutrition Trial (InFANT Extend Program builds on the early outcomes of the Melbourne InFANT Program. This cluster randomized controlled trial will test the efficacy of an extended (33 versus 15 month and enhanced (use of web-based materials, and Facebook® engagement, version of the original Melbourne InFANT Program intervention in a new cohort. Outcomes at 36 months of age will be compared against the control group. Discussion This trial will provide important information regarding capacity and opportunities to maximize early childhood intervention effectiveness over the first three years of life. This study continues to build the evidence base regarding the design of cost-effective, scalable interventions to promote protective energy balance behaviors in early childhood, and in turn, promote improved child weight and health across the life course. Trial registration ACTRN12611000386932 . Registered 13 April 2011.

  16. The effectiveness of the Austrian disease management programme for type 2 diabetes: a cluster-randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Klima Gert

    2010-11-01

    Full Text Available Abstract Background Disease management programmes (DMPs are costly and impose additional work load on general practitioners (GPs. Data on their effectiveness are inconclusive. We therefore conducted a cluster-randomised controlled trial to evaluate the effectiveness of the Austrian DMP for diabetes mellitus type 2 on HbA1c and quality of care for adult patients in primary care. Methods All GPs of Salzburg-province were invited to participate. After cluster-randomisation by district, all patients with diabetes type 2 were recruited consecutively from 7-11/2007. The DMP, consisting mainly of physician and patient education, standardised documentation and agreement on therapeutic goals, was implemented in the intervention group while the control group received usual care. We aimed to show superiority of the intervention regarding metabolic control and process quality. The primary outcome measure was a change in HbA1c after one year. Secondary outcomes were days in the hospital, blood pressure, lipids, body mass index (BMI, enrolment in patient education and regular guideline-adherent examination. Blinding was not possible. Results 92 physicians recruited 1489 patients (649 intervention, 840 control. After 401 ± 47 days, 590 intervention-patients and 754 controls had complete data. In the intention to treat analysis (ITT of all 1489 patients, HbA1c decreased 0.41% in the intervention group and 0.28% in controls. The difference of -0.13% (95% CI -0.24; -0.02 was significant at p = 0.026. Significance was lost in mixed models adjusted for baseline value and cluster-effects (adjusted mean difference -0.03 (95% CI -0.15; 0.09, p = 0.607. Of the secondary outcome measures, BMI and cholesterol were significantly reduced in the intervention group compared to controls in ITT after adjustments (-0.53 kg/m²; 95% CI -1.03;-0.02; p = 0.014 and -0.10 mmol/l; 95% CI -0.21; -0.003; p = 0.043. Additionally, more patients received patient education (49.5% vs. 20

  17. Effectiveness of the EMPOWER-PAR Intervention in Improving Clinical Outcomes of Type 2 Diabetes Mellitus in Primary Care: A Pragmatic Cluster Randomised Controlled Trial.

    Science.gov (United States)

    Ramli, Anis Safura; Selvarajah, Sharmini; Daud, Maryam Hannah; Haniff, Jamaiyah; Abdul-Razak, Suraya; Tg-Abu-Bakar-Sidik, Tg Mohd Ikhwan; Bujang, Mohamad Adam; Chew, Boon How; Rahman, Thuhairah; Tong, Seng Fah; Shafie, Asrul Akmal; Lee, Verna K M; Ng, Kien Keat; Ariffin, Farnaza; Abdul-Hamid, Hasidah; Mazapuspavina, Md Yasin; Mat-Nasir, Nafiza; Chan, Chun W; Yong-Rafidah, Abdul Rahman; Ismail, Mastura; Lakshmanan, Sharmila; Low, Wilson H H

    2016-11-14

    The chronic care model was proven effective in improving clinical outcomes of diabetes in developed countries. However, evidence in developing countries is scarce. The objective of this study was to evaluate the effectiveness of EMPOWER-PAR intervention (based on the chronic care model) in improving clinical outcomes for type 2 diabetes mellitus using readily available resources in the Malaysian public primary care setting. This was a pragmatic, cluster-randomised, parallel, matched pair, controlled trial using participatory action research approach, conducted in 10 public primary care clinics in Malaysia. Five clinics were randomly selected to provide the EMPOWER-PAR intervention for 1 year and another five clinics continued with usual care. Patients who fulfilled the criteria were recruited over a 2-week period by each clinic. The obligatory intervention components were designed based on four elements of the chronic care model i.e. healthcare organisation, delivery system design, self-management support and decision support. The primary outcome was the change in the proportion of patients achieving HbA1c diabetes mellitus patients were recruited at baseline (intervention: 471 vs. 417). At 1-year, 96.6 and 97.8% of patients in the intervention and control groups completed the study, respectively. The baseline demographic and clinical characteristics of both groups were comparable. The change in the proportion of patients achieving HbA1c target was significantly higher in the intervention compared to the control group (intervention: 3.0% vs. -4.1%, P diabetes in the Malaysian public primary care setting. Registered with: ClinicalTrials.gov.: NCT01545401 . Date of registration: 1st March 2012.

  18. Accounting for multiple births in randomised trials: a systematic review.

    Science.gov (United States)

    Yelland, Lisa Nicole; Sullivan, Thomas Richard; Makrides, Maria

    2015-03-01

    Multiple births are an important subgroup to consider in trials aimed at reducing preterm birth or its consequences. Including multiples results in a unique mixture of independent and clustered data, which has implications for the design, analysis and reporting of the trial. We aimed to determine how multiple births were taken into account in the design and analysis of recent trials involving preterm infants, and whether key information relevant to multiple births was reported. We conducted a systematic review of multicentre randomised trials involving preterm infants published between 2008 and 2013. Information relevant to multiple births was extracted. Of the 56 trials included in the review, 6 (11%) excluded multiples and 24 (43%) failed to indicate whether multiples were included. Among the 26 trials that reported multiples were included, only one (4%) accounted for clustering in the sample size calculations and eight (31%) took the clustering into account in the analysis of the primary outcome. Of the 20 trials that randomised infants, 12 (60%) failed to report how infants from the same birth were randomised. Information on multiple births is often poorly reported in trials involving preterm infants, and clustering due to multiple births is rarely taken into account. Since ignoring clustering could result in inappropriate recommendations for clinical practice, clustering should be taken into account in the design and analysis of future neonatal and perinatal trials including infants from a multiple birth. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  19. Clusters of Galaxies

    Science.gov (United States)

    Huchtmeier, W. K.; Richter, O. G.; Materne, J.

    1981-09-01

    The large-scale structure of the universe is dominated by clustering. Most galaxies seem to be members of pairs, groups, clusters, and superclusters. To that degree we are able to recognize a hierarchical structure of the universe. Our local group of galaxies (LG) is centred on two large spiral galaxies: the Andromeda nebula and our own galaxy. Three sr:naller galaxies - like M 33 - and at least 23 dwarf galaxies (KraanKorteweg and Tammann, 1979, Astronomische Nachrichten, 300, 181) can be found in the evironment of these two large galaxies. Neighbouring groups have comparable sizes (about 1 Mpc in extent) and comparable numbers of bright members. Small dwarf galaxies cannot at present be observed at great distances.

  20. Proactive palliative care for patients with COPD (PROLONG: a pragmatic cluster controlled trial

    Directory of Open Access Journals (Sweden)

    Duenk RG

    2017-09-01

    Full Text Available RG Duenk,1 C Verhagen,1 EM Bronkhorst,2 PJWB van Mierlo,3,4 MEAC Broeders,5 SM Collard,6 PNR Dekhuijzen,7 KCP Vissers,1 Y Heijdra,7,* Y Engels1,* 1Department of Anesthesiology, Pain and Palliative Medicine, 2Department of Health Evidence, Radboud University Medical Center, Nijmegen, 3Department of Supportive and Palliative Medicine, 4Department of Geriatric Medicine, Rijnstate Hospital, Arnhem, 5Department of Pulmonary Diseases, Jeroen Bosch Hospital, ‘s-Hertogenbosch, 6Department of Pulmonary Diseases, Meander Medical Center, Amersfoort, 7Department of Pulmonary Diseases, Radboud University Medical Center, Nijmegen, the Netherlands *These authors contributed equally to this work Background and aim: Patients with advanced chronic obstructive pulmonary disease (COPD have poor quality of life. The aim of this study was to assess the effects of proactive palliative care on the well-being of these patients.Trial registration: This trial is registered with the Netherlands Trial Register, NTR4037.Patients and methods: A pragmatic cluster controlled trial (quasi-experimental design was performed with hospitals as cluster (three intervention and three control and a pretrial assessment was performed. Hospitals were selected for the intervention group based on the presence of a specialized palliative care team (SPCT. To control for confounders, a pretrial assessment was performed in which hospitals were compared on baseline characteristics. Patients with COPD with poor prognosis were recruited during hospitalization for acute exacerbation. All patients received usual care while patients in the intervention group received additional proactive palliative care in monthly meetings with an SPCT. Our primary outcome was change in quality of life score after 3 months, which was measured using the St George Respiratory Questionnaire (SGRQ. Secondary outcomes were, among others, quality of life at 6, 9 and 12 months; readmissions: survival; and having made

  1. Effect of a mass radio campaign on family behaviours and child survival in Burkina Faso: a repeated cross-sectional, cluster-randomised trial

    Directory of Open Access Journals (Sweden)

    Sophie Sarrassat, PhD

    2018-03-01

    Full Text Available Summary: Background: Media campaigns can potentially reach a large audience at relatively low cost but, to our knowledge, no randomised controlled trials have assessed their effect on a health outcome in a low-income country. We aimed to assess the effect of a radio campaign addressing family behaviours on all-cause post-neonatal under-5 child mortality in rural Burkina Faso. Methods: In this repeated cross-sectional, cluster randomised trial, clusters (distinct geographical areas in rural Burkina Faso with at least 40 000 inhabitants were selected by Development Media International based on their high radio listenership (>60% of women listening to the radio in the past week and minimum distances between radio stations to exclude population-level contamination. Clusters were randomly allocated to receive the intervention (a comprehensive radio campaign or control group (no radio media campaign. Household surveys were performed at baseline (from December, 2011, to February, 2012, midline (in November, 2013, and after 20 months of campaigning, and endline (from November, 2014, to March, 2015, after 32 months of campaigning. Primary analyses were done on an intention-to-treat basis, based on cluster-level summaries and adjusted for imbalances between groups at baseline. The primary outcome was all-cause post-neonatal under-5 child mortality. The trial was designed to detect a 20% reduction in the primary outcome with a power of 80%. Routine data from health facilities were also analysed for evidence of changes in use and these data had high statistical power. The indicators measured were new antenatal care attendances, facility deliveries, and under-5 consultations. This trial is registered with ClinicalTrial.gov, number NCT01517230. Findings: The intervention ran from March, 2012, to January, 2015. 14 clusters were selected and randomly assigned to the intervention group (n=7 or the control group (n=7. The average number of villages included per

  2. Generic care pathway for elderly patients in need of home care services after discharge from hospital: a cluster randomised controlled trial.

    Science.gov (United States)

    Røsstad, Tove; Salvesen, Øyvind; Steinsbekk, Aslak; Grimsmo, Anders; Sletvold, Olav; Garåsen, Helge

    2017-04-17

    Improved discharge arrangements and targeted post-discharge follow-up can reduce the risk of adverse events after hospital discharge for elderly patients. Although more care is to shift from specialist to primary care, there are few studies on post-discharge interventions run by primary care. A generic care pathway, Patient Trajectory for Home-dwelling elders (PaTH) including discharge arrangements and follow-up by primary care, was developed and introduced in Central Norway Region in 2009, applying checklists at defined stages in the patient trajectory. In a previous paper, we found that PaTH had potential of improving follow-up in primary care. The aim of this study was to establish the effect of PaTH-compared to usual care-for elderly in need of home care services after discharge from hospital. We did an unblinded, cluster randomised controlled trial with 12 home care clusters. Outcomes were measured at the patient level during a 12-month follow-up period for the individual patient and analysed applying linear and logistic mixed models. Primary outcomes were readmissions within 30 days and functional level assessed by Nottingham extended ADL scale. Secondary outcomes were number and length of inpatient hospital care and nursing home care, days at home, consultations with the general practitioners (GPs), mortality and health related quality of life (SF-36). One-hundred and sixty-three patients were included in the PaTH group (six clusters), and 141 patients received care as usual (six clusters). We found no statistically significant differences between the groups for primary and secondary outcomes except for more consultations with the GPs in PaTH group (p = 0.04). Adherence to the intervention was insufficient as only 36% of the patients in the intervention group were assessed by at least three of the four main checklists in PaTH, but this improved over time. Lack of adherence to PaTH rendered the study inconclusive regarding the elderly's functional level

  3. Real-time observation of formation and relaxation dynamics of NH4 in (CH3OH)m(NH3)n clusters.

    Science.gov (United States)

    Yamada, Yuji; Nishino, Yoko; Fujihara, Akimasa; Ishikawa, Haruki; Fuke, Kiyokazu

    2009-03-26

    The formation and relaxation dynamics of NH4(CH3OH)m(NH3)n clusters produced by photolysis of ammonia-methanol mixed clusters has been observed by a time-resolved pump-probe method with femtosecond pulse lasers. From the detailed analysis of the time evolutions of the protonated cluster ions, NH4(+)(CH3OH)m(NH3)n, the kinetic model has been constructed, which consists of sequential three-step reaction: ultrafast hydrogen-atom transfer producing the radical pair (NH4-NH2)*, the relaxation process of radical-pair clusters, and dissociation of the solvated NH4 clusters. The initial hydrogen transfer hardly occurs between ammonia and methanol, implying the unfavorable formation of radical pair, (CH3OH2-NH2)*. The remarkable dependence of the time constants in each step on the number and composition of solvents has been explained by the following factors: hydrogen delocalization within the clusters, the internal conversion of the excited-state radical pair, and the stabilization of NH4 by solvation. The dependence of the time profiles on the probe wavelength is attributed to the different ionization efficiency of the NH4(CH3OH)m(NH3)n clusters.

  4. Protocol for a feasibility cluster randomised controlled trial of a peer-led school-based intervention to increase the physical activity of adolescent girls (PLAN-A).

    Science.gov (United States)

    Sebire, Simon J; Edwards, Mark J; Campbell, Rona; Jago, Russell; Kipping, Ruth; Banfield, Kathryn; Tomkinson, Keeley; Garfield, Kirsty; Lyons, Ronan A; Simon, Joanne; Blair, Peter S; Hollingworth, William

    2016-01-01

    Physical activity levels are low amongst adolescent girls, and this population faces specific barriers to being active. Peer influences on health behaviours are important in adolescence and peer-led interventions might hold promise to change behaviour. This paper describes the protocol for a feasibility cluster randomised controlled trial of Peer-Led physical Activity iNtervention for Adolescent girls (PLAN-A), a peer-led intervention aimed at increasing adolescent girls' physical activity levels. A two-arm cluster randomised feasibility trial will be conducted in six secondary schools (intervention n  = 4; control n  = 2) with year 8 (12-13 years old) girls. The intervention will operate at a year group level and consist of year 8 girls nominating influential peers within their year group to become peer-supporters. Approximately 15 % of the cohort will receive 3 days of training about physical activity and interpersonal communication skills. Peer-supporters will then informally diffuse messages about physical activity amongst their friends for 10 weeks. Data will be collected at baseline (time 0 (T0)), immediately after the intervention (time 1 (T1)) and 12 months after baseline measures (time 2 (T2)). In this feasibility trial, the primary interest is in the recruitment of schools and participants (both year 8 girls and peer-supporters), delivery and receipt of the intervention, data provision rates and identifying the cost categories for future economic analysis. Physical activity will be assessed using 7-day accelerometry, with the likely primary outcome in a fully-powered trial being daily minutes of moderate-to-vigorous physical activity. Participants will also complete psychosocial questionnaires at each time point: assessing motivation, self-esteem and peer physical activity norms. Data analysis will be largely descriptive and focus on recruitment, attendance and data provision rates. The findings will inform the sample size required for a

  5. 6-PACK programme to decrease fall injuries in acute hospitals: cluster randomised controlled trial.

    Science.gov (United States)

    Barker, Anna L; Morello, Renata T; Wolfe, Rory; Brand, Caroline A; Haines, Terry P; Hill, Keith D; Brauer, Sandra G; Botti, Mari; Cumming, Robert G; Livingston, Patricia M; Sherrington, Catherine; Zavarsek, Silva; Lindley, Richard I; Kamar, Jeannette

    2016-01-26

    To evaluate the effect of the 6-PACK programme on falls and fall injuries in acute wards. Cluster randomised controlled trial. Six Australian hospitals. All patients admitted to 24 acute wards during the trial period. Participating wards were randomly assigned to receive either the nurse led 6-PACK programme or usual care over 12 months. The 6-PACK programme included a fall risk tool and individualised use of one or more of six interventions: "falls alert" sign, supervision of patients in the bathroom, ensuring patients' walking aids are within reach, a toileting regimen, use of a low-low bed, and use of a bed/chair alarm. The co-primary outcomes were falls and fall injuries per 1000 occupied bed days. During the trial, 46 245 admissions to 16 medical and eight surgical wards occurred. As many people were admitted more than once, this represented 31 411 individual patients. Patients' characteristics and length of stay were similar for intervention and control wards. Use of 6-PACK programme components was higher on intervention wards than on control wards (incidence rate ratio 3.05, 95% confidence interval 2.14 to 4.34; Pcontrol wards. Positive changes in falls prevention practice occurred following the introduction of the 6-PACK programme. However, no difference was seen in falls or fall injuries between groups. High quality evidence showing the effectiveness of falls prevention interventions in acute wards remains absent. Novel solutions to the problem of in-hospital falls are urgently needed. Australian New Zealand Clinical Trials Registry ACTRN12611000332921. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  6. Pilot cluster randomised controlled trial of flooring to reduce injuries from falls in elderly care units: study protocol.

    Science.gov (United States)

    Drahota, Amy; Gal, Diane; Windsor, Julie; Dixon, Simon; Udell, Julie; Ward, Derek; Soilemezi, Dia; Dean, Taraneh; Severs, Martin

    2011-12-01

    Falls are an issue disproportionately affecting older people who are at increased risk of falls and injury. This protocol describes a pilot study investigating shock-absorbing flooring for fall-related injuries in wards for older people. To inform future research by evaluating fall-related injuries on the intervention and existing flooring, assessing the sustainability of the flooring in ward environments, estimating the cost-effectiveness of the floor and assessing how the floor affects patients and other users. This study uses mixed methods a pilot cluster randomised controlled trial, observation via mechanical testing and interviews. Eight participating wards (clusters) are randomised using a computer-generated list. No blinding is incorporated into the study. Each site has a baseline period of approximately 6 months. Then, four sites receive the intervention floor, while four continue using standard floors. Sites are then followed up for approximately 1 year. Any person admitted to a bed in the 'study area' of a participating ward can be entered into the trial. Orientated patients, visitors and any hospital staff who use the floor in a study area are eligible for inclusion in an interview. An 8.3 mm thick vinyl floor covering with polyvinyl chloride foam backing (Tarkett Omnisports EXCEL). The primary outcome is fall-related injuries. Severity of injuries, falls, cost-effectiveness, user views and mechanical performance (shock absorbency and slip resistance) are also being assessed.

  7. Probability of coincidental similarity among the orbits of small bodies - I. Pairing

    Science.gov (United States)

    Jopek, Tadeusz Jan; Bronikowska, Małgorzata

    2017-09-01

    Probability of coincidental clustering among orbits of comets, asteroids and meteoroids depends on many factors like: the size of the orbital sample searched for clusters or the size of the identified group, it is different for groups of 2,3,4,… members. Probability of coincidental clustering is assessed by the numerical simulation, therefore, it depends also on the method used for the synthetic orbits generation. We have tested the impact of some of these factors. For a given size of the orbital sample we have assessed probability of random pairing among several orbital populations of different sizes. We have found how these probabilities vary with the size of the orbital samples. Finally, keeping fixed size of the orbital sample we have shown that the probability of random pairing can be significantly different for the orbital samples obtained by different observation techniques. Also for the user convenience we have obtained several formulae which, for given size of the orbital sample can be used to calculate the similarity threshold corresponding to the small value of the probability of coincidental similarity among two orbits.

  8. The initial stages of NaCl dissolution: Ion or ion pair solvation?

    Science.gov (United States)

    Klimes, Jiri; Michaelides, Angelos

    2009-03-01

    The interaction of water with rock salt (NaCl) is important in a wide variety of natural processes and human activities. A lot is known about NaCl dissolution at the macroscopic level but we do not yet have a detailed atomic scale picture of how salt crystals dissolve. Here we report an extensive series of density functional theory, forcefield and molecular dynamics studies of water clusters at flat and defective NaCl surfaces and NaCl clusters. The focus is on answering seemingly elementary questions such as how many water molecules are needed before it becomes favorable to extract an ion or a pair of ions from the crystal or the cluster. It turns out, however, that the answers to these questions are not so straightforward: below a certain number of water molecules (˜ 12) solvation of individual ions is less costly and above this number solvation of ion pairs is favored. These results reveal a hitherto unknown complexity in the NaCl dissolution process born out of a subtle interplay between water-water and water-ion interactions.

  9. The Cluster-Randomized BRIGHT Trial: Proactive Case Finding for Community-Dwelling Older Adults

    Science.gov (United States)

    Kerse, Ngaire; McLean, Chris; Moyes, Simon A.; Peri, Kathy; Ng, Terence; Wilkinson-Meyers, Laura; Brown, Paul; Latham, Nancy; Connolly, Martin

    2014-01-01

    PURPOSE People are now living longer, but disability may affect the quality of those additional years of life. We undertook a trial to assess whether case finding reduces disability among older primary care patients. METHODS We conducted a cluster-randomized trial of the Brief Risk Identification Geriatric Health Tool (BRIGHT) among 60 primary care practices in New Zealand, assigning them to an intervention or control group. Intervention practices sent a BRIGHT screening tool to older adults every birthday; those with a score of 3 or higher were referred to regional geriatric services for assessment and, if needed, service provision. Control practices provided usual care. Main outcomes, assessed in blinded fashion, were residential care placement and hospitalization, and secondary outcomes were disability, assessed with Nottingham Extended Activities of Daily Living Scale (NEADL), and quality of life, assessed with the World Health Organization Quality of Life scale, abbreviated version (WHOQOL-BREF). RESULTS All 8,308 community-dwelling patients aged 75 years and older were approached; 3,893 (47%) participated, of whom 3,010 (77%) completed the trial. Their mean age was 80.3 (SD 4.5) years, and 55% were women. Overall, 88% of the intervention group returned a BRIGHT tool; 549 patients were referred. After 36 months, patients in the intervention group were more likely than those in the control group to have been placed in residential care: 8.4% vs 6.2% (hazard ratio = 1.32; 95% CI, 1.04–1.68; P = .02). Intervention patients had smaller declines in mean scores for physical health-related quality of life (1.6 vs 2.9 points, P = .007) and psychological health-related quality of life (1.1 vs 2.4 points, P = .005). Hospitalization, disability, and use of services did not differ between groups, however. CONCLUSIONS Our case-finding strategy was effective in increasing identification of older adults with disability, but there was little evidence of improved outcomes

  10. Evidence-based care of older people with suspected cognitive impairment in general practice: protocol for the IRIS cluster randomised trial.

    Science.gov (United States)

    McKenzie, Joanne E; French, Simon D; O'Connor, Denise A; Mortimer, Duncan S; Browning, Colette J; Russell, Grant M; Grimshaw, Jeremy M; Eccles, Martin P; Francis, Jill J; Michie, Susan; Murphy, Kerry; Kossenas, Fiona; Green, Sally E

    2013-08-19

    Dementia is a common and complex condition. Evidence-based guidelines for the management of people with dementia in general practice exist; however, detection, diagnosis and disclosure of dementia have been identified as potential evidence-practice gaps. Interventions to implement guidelines into practice have had varying success. The use of theory in designing implementation interventions has been limited, but is advocated because of its potential to yield more effective interventions and aid understanding of factors modifying the magnitude of intervention effects across trials. This protocol describes methods of a randomised trial that tests a theory-informed implementation intervention that, if effective, may provide benefits for patients with dementia and their carers. This trial aims to estimate the effectiveness of a theory-informed intervention to increase GPs' (in Victoria, Australia) adherence to a clinical guideline for the detection, diagnosis, and management of dementia in general practice, compared with providing GPs with a printed copy of the guideline. Primary objectives include testing if the intervention is effective in increasing the percentage of patients with suspected cognitive impairment who receive care consistent with two key guideline recommendations: receipt of a i) formal cognitive assessment, and ii) depression assessment using a validated scale (primary outcomes for the trial). The design is a parallel cluster randomised trial, with clusters being general practices. We aim to recruit 60 practices per group. Practices will be randomised to the intervention and control groups using restricted randomisation. Patients meeting the inclusion criteria, and GPs' detection and diagnosis behaviours directed toward these patients, will be identified and measured via an electronic search of the medical records nine months after the start of the intervention. Practitioners in the control group will receive a printed copy of the guideline. In

  11. PRALIMAP: study protocol for a high school-based, factorial cluster randomised interventional trial of three overweight and obesity prevention strategies

    Directory of Open Access Journals (Sweden)

    Agrinier Nelly

    2010-12-01

    Full Text Available Abstract Background Given the increase in overweight and obesity prevalence in adolescents in the last decade, effective prevention strategies for these conditions in adolescents are urgently needed. The PRALIMAP (Promotion de l'ALImentation et de l'Activité Physique trial aims to evaluate the effectiveness for these conditions of 3 health promotion strategies -- educational, screening and environmental -- applied singly or in combination in high schools over a 2-year intervention period. Methods PRALIMAP is a stratified 2 × 2 × 2 factorial cluster randomised controlled trial including 24 state high schools in Lorraine, northeastern France, in 2 waves: 8 schools in 2006 (wave 1 and 16 in 2007 (wave 2. Students entering the selected high schools in the 4 academic years from 2006 to 2009 are eligible for data collection. Interventional strategies are organized over 2 academic years. The follow-up consists of 3 visits: at the entry of grade 10 (T0, grade 11 (T1 and grade 12 (T2. At T0, 5,458 (85.7% adolescents participated. The educational strategy consists of nutritional lessons, working groups and a final party. The screening strategy consists in detecting overweight/obesity and eating disorders in adolescents and proposing, if necessary, an adapted care management program of 7 group educational sessions. The environmental strategy consists in improving dietary and physical activity offerings in high schools and facilities, especially catering. The main outcomes are body size evolution over time, nutritional behaviour and knowledge, health and quality of life. An evaluation process documents how each intervention strategy is implemented in the schools and estimates the dose of the intervention, allowing for a per protocol analysis after the main intention-to-treat analysis. Discussion PRALIMAP aims at improving the prevention and management of overweight and obesity in adolescents by translating current evidence into public health practice

  12. Effects of quality improvement in health facilities and community mobilization through women's groups on maternal, neonatal and perinatal mortality in three districts of Malawi: MaiKhanda, a cluster randomized controlled effectiveness trial.

    Science.gov (United States)

    Colbourn, Tim; Nambiar, Bejoy; Bondo, Austin; Makwenda, Charles; Tsetekani, Eric; Makonda-Ridley, Agnes; Msukwa, Martin; Barker, Pierre; Kotagal, Uma; Williams, Cassie; Davies, Ros; Webb, Dale; Flatman, Dorothy; Lewycka, Sonia; Rosato, Mikey; Kachale, Fannie; Mwansambo, Charles; Costello, Anthony

    2013-09-01

    Maternal, perinatal and neonatal mortality remains high in low-income countries. We evaluated community and facility-based interventions to reduce deaths in three districts of Malawi. We evaluated a rural participatory women's group community intervention (CI) and a quality improvement intervention at health centres (FI) via a two-by-two factorial cluster randomized controlled trial. Consenting pregnant women were followed-up to 2 months after birth using key informants. Primary outcomes were maternal, perinatal and neonatal mortality. Clusters were health centre catchment areas assigned using stratified computer-generated randomization. Following exclusions, including non-birthing facilities, 61 clusters were analysed: control (17 clusters, 4912 births), FI (15, 5335), CI (15, 5080) and FI + CI (14, 5249). This trial was registered as International Standard Randomised Controlled Trial [ISRCTN18073903]. Outcomes for 14,576 and 20,576 births were recorded during baseline (June 2007-September 2008) and intervention (October 2008-December 2010) periods. For control, FI, CI and FI + CI clusters neonatal mortality rates were 34.0, 28.3, 29.9 and 27.0 neonatal deaths per 1000 live births and perinatal mortality rates were 56.2, 55.1, 48.0 and 48.4 per 1000 births, during the intervention period. Adjusting for clustering and stratification, the neonatal mortality rate was 22% lower in FI + CI than control clusters (OR = 0.78, 95% CI 0.60-1.01), and the perinatal mortality rate was 16% lower in CI clusters (OR = 0.84, 95% CI 0.72-0.97). We did not observe any intervention effects on maternal mortality. Despite implementation problems, a combined community and facility approach using participatory women's groups and quality improvement at health centres reduced newborn mortality in rural Malawi.

  13. Non-standard base pairing and stacked structures in methyl xanthine clusters

    Czech Academy of Sciences Publication Activity Database

    Callahan, M. P.; Gengeliczki, Z.; Svadlenak, N.; Valdes, Haydee; Hobza, Pavel; de Vries, M. S.

    2008-01-01

    Roč. 10, č. 19 (2008), s. 2819-2826 ISSN 1463-9076 R&D Projects: GA MŠk LC512 Grant - others:NSF(US) CHE-0615401 Institutional research plan: CEZ:AV0Z40550506 Keywords : non-standard base pairing * stacked structures * in methyl xanthine Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.064, year: 2008

  14. REFOCUS Trial: protocol for a cluster randomised controlled trial of a pro-recovery intervention within community based mental health teams

    Directory of Open Access Journals (Sweden)

    Slade Mike

    2011-11-01

    Full Text Available Abstract Background There is a consensus about the importance of 'recovery' in mental health services, but the evidence base is limited. Methods/Design A two centre, cluster randomised controlled trial. Participants are community-based mental health teams, and service users aged 18-65 years with a primary clinical diagnosis of psychosis. In relation to the REFOCUS Manual researchintorecovery.com/refocus, which describes a 12-month, pro-recovery intervention based on the REFOCUS Model, the objectives are: (1 To establish the effectiveness of the intervention described in the REFOCUS Manual; (2 To validate the REFOCUS Model; (3 To establish and optimise trial parameters for the REFOCUS Manual; and (4 To understand the relationship between clinical outcomes and recovery outcomes. The hypothesis for the main study is that service users in the intervention arm will experience significantly greater increases in measures of personal recovery (as measured by the QPR compared to service users receiving care from control teams. The hypothesis for the secondary study is that black service users in the intervention arm will experience significantly greater increases in measures of personal recovery (as measured by the QPR and client satisfaction (as measured by the CSQ compared to Black service users receiving care from control teams. The intervention comprises treatment as usual plus two components: recovery-promoting relationships and working practices. The control condition is treatment as usual. The primary outcme is the Process of Recovery Questionnaire (QPR. Secondary outcomes are satisfaction, Goal setting - Personal Primary Outcome, hope, well-being, empowerment, and quality of life. Primary outcomes for the secondary study will be QPR and satisfaction. Cost data will be estimated, and clinical outcomes will also be reported (symptomatology, need, social disability, functioning. 29 teams (15 intervention and 14 control will be randomised. Within

  15. Randomised trial on episodic cluster headache with an angiotensin II receptor blocker

    DEFF Research Database (Denmark)

    Tronvik, Erling; Wienecke, Troels; Monstad, Inge

    2013-01-01

    OBJECTIVES: The aim of this study was to evaluate the angiotensin II receptor antagonist candesartan as prophylactic medication in patients with episodic cluster headache. METHODS: This study comprised a prospective, placebo-controlled, double-blind, parallel-designed trial performed in seven cen...... the candesartan and placebo group was not significant with the pre-planned non-parametric ranking test, but a post-hoc exact Poisson test, which takes into account the temporal properties of the data, revealed a significant result ( P  ...... (primary efficacy variable) during the three-week treatment period was reduced from 14.3 ± 9.2 attacks in week 1 to 5.6 ± 7.0 attacks in week 3 (-61%) in the candesartan group and from 16.8 ± 14.1 attacks in week 1 to 10.5 ± 11.3 attacks in week 3 (-38%) in the placebo group. The difference between...

  16. Fission of Polyanionic Metal Clusters

    Science.gov (United States)

    König, S.; Jankowski, A.; Marx, G.; Schweikhard, L.; Wolfram, M.

    2018-04-01

    Size-selected dianionic lead clusters Pbn2 -, n =34 - 56 , are stored in a Penning trap and studied with respect to their decay products upon photoexcitation. Contrary to the decay of other dianionic metal clusters, these lead clusters show a variety of decay channels. The mass spectra of the fragments are compared to the corresponding spectra of the monoanionic precursors. This comparison leads to the conclusion that, in the cluster size region below about n =48 , the fission reaction Pbn2 -→Pbn-10 -+Pb10- is the major decay process. Its disappearance at larger cluster sizes may be an indication of a nonmetal to metal transition. Recently, the pair of Pb10- and Pbn-10 - were observed as pronounced fragments in electron-attachment studies [S. König et al., Int. J. Mass Spectrom. 421, 129 (2017), 10.1016/j.ijms.2017.06.009]. The present findings suggest that this combination is the fingerprint of the decay of doubly charged lead clusters. With this assumption, the dianion clusters have been traced down to Pb212 -, whereas the smallest size for the direct observation was as high as n =28 .

  17. Growing Right Onto Wellness (GROW): a family-centered, community-based obesity prevention randomized controlled trial for preschool child-parent pairs.

    Science.gov (United States)

    Po'e, Eli K; Heerman, William J; Mistry, Rishi S; Barkin, Shari L

    2013-11-01

    Growing Right Onto Wellness (GROW) is a randomized controlled trial that tests the efficacy of a family-centered, community-based, behavioral intervention to prevent childhood obesity among preschool-aged children. Focusing on parent-child pairs, GROW utilizes a multi-level framework, which accounts for macro (i.e., built-environment) and micro (i.e., genetics) level systems that contribute to the childhood obesity epidemic. Six hundred parent-child pairs will be randomized to a 3-year healthy lifestyle intervention or a 3-year school readiness program. Eligible children are enrolled between ages 3 and 5, are from minority communities, and are not obese. The principal site for the GROW intervention is local community recreation centers and libraries. The primary outcome is childhood body mass index (BMI) trajectory at the end of the three-year study period. In addition to other anthropometric measurements, mediators and moderators of growth are considered, including genetics, accelerometry, and diet recall. GROW is a staged intensity intervention, consisting of intensive, maintenance, and sustainability phases. Throughout the study, parents build skills in nutrition, physical activity, and parenting, concurrently forming new social networks. Participants are taught goal-setting, self-monitoring, and problem solving techniques to facilitate sustainable behavior change. The GROW curriculum uses low health literacy communication and social media to communicate key health messages. The control arm is administered to both control and intervention participants. By conducting this trial in public community centers, and by implementing a family-centered approach to sustainable healthy childhood growth, we aim to develop an exportable community-based intervention to address the expanding public health crisis of pediatric obesity. © 2013.

  18. Centromeres cluster de novo at the beginning of meiosis in Brachypodium distachyon.

    Directory of Open Access Journals (Sweden)

    Ruoyu Wen

    Full Text Available In most eukaryotes that have been studied, the telomeres cluster into a bouquet early in meiosis, and in wheat and its relatives and in Arabidopsis the centromeres pair at the same time. In Arabidopsis, the telomeres do not cluster as a typical telomere bouquet on the nuclear membrane but are associated with the nucleolus both somatically and at the onset of meiosis. We therefore assessed whether Brachypodium distachyon, a monocot species related to cereals and whose genome is approximately twice the size of Arabidopsis thaliana, also exhibited an atypical telomere bouquet and centromere pairing. In order to investigate the occurrence of a bouquet and centromere pairing in B distachyon, we first had to establish protocols for studying meiosis in this species. This enabled us to visualize chromosome behaviour in meiocytes derived from young B distachyon spikelets in three-dimensions by fluorescent in situ hybridization (FISH, and accurately to stage meiosis based on chromatin morphology in relation to spikelet size and the timing of sample collection. Surprisingly, this study revealed that the centromeres clustered as a single site at the same time as the telomeres also formed a bouquet or single cluster.

  19. Implementing a complex intervention to support personal recovery: a qualitative study nested within a cluster randomised controlled trial.

    Directory of Open Access Journals (Sweden)

    Mary Leamy

    Full Text Available OBJECTIVE: To investigate staff and trainer perspectives on the barriers and facilitators to implementing a complex intervention to help staff support the recovery of service users with a primary diagnosis of psychosis in community mental health teams. DESIGN: Process evaluation nested within a cluster randomised controlled trial (RCT. PARTICIPANTS: 28 interviews with mental health care staff, 3 interviews with trainers, 4 focus groups with intervention teams and 28 written trainer reports. SETTING: 14 community-based mental health teams in two UK sites (one urban, one semi-rural who received the intervention. RESULTS: The factors influencing the implementation of the intervention can be organised under two over-arching themes: Organisational readiness for change and Training effectiveness. Organisational readiness for change comprised three sub-themes: NHS Trust readiness; Team readiness; and Practitioner readiness. Training effectiveness comprised three sub-themes: Engagement strategies; Delivery style and Modelling recovery principles. CONCLUSIONS: Three findings can inform future implementation and evaluation of complex interventions. First, the underlying intervention model predicted that three areas would be important for changing practice: staff skill development; intention to implement; and actual implementation behaviour. This study highlighted the importance of targeting the transition from practitioners' intent to implement to actual implementation behaviour, using experiential learning and target setting. Second, practitioners make inferences about organisational commitment by observing the allocation of resources, Knowledge Performance Indicators and service evaluation outcome measures. These need to be aligned with recovery values, principles and practice. Finally, we recommend the use of organisational readiness tools as an inclusion criteria for selecting both organisations and teams in cluster RCTs. We believe this would

  20. Electronically driven short-range lattice instability: Possible role in superconductive pairing

    International Nuclear Information System (INIS)

    Szasz, A.

    1991-01-01

    A superconducting pairing mechanism is suggested, mediating by collective and coherent cluster fluctuations in the materials. The model, based on a geometrical frustration, proposes a dynamic effect driven by a special short-range electronic instability. Experimental support for this model is discussed

  1. Cost-Effectiveness of a Long-Term Internet-Delivered Worksite Health Promotion Programme on Physical Activity and Nutrition: A Cluster Randomized Controlled Trial

    Science.gov (United States)

    Robroek, Suzan J. W.; Polinder, Suzanne; Bredt, Folef J.; Burdorf, Alex

    2012-01-01

    This study aims to evaluate the cost-effectiveness of a long-term workplace health promotion programme on physical activity (PA) and nutrition. In total, 924 participants enrolled in a 2-year cluster randomized controlled trial, with departments (n = 74) within companies (n = 6) as the unit of randomization. The intervention was compared with a…

  2. Adding a post-training FIFA 11+ exercise program to the pre-training FIFA 11+ injury prevention program reduces injury rates among male amateur soccer players: a cluster-randomised trial

    Directory of Open Access Journals (Sweden)

    Wesam Saleh A Al Attar

    2017-10-01

    Trial registration: ACTRN12615001206516. [Al Attar WSA, Soomro N, Pappas E, Sinclair PJ, Sanders RH (2017 Adding a post-training FIFA 11+ exercise program to the pre-training FIFA 11+ injury prevention program reduces injury rates among male amateur soccer players: a cluster-randomised trial. Journal of Physiotherapy 63: 235–242

  3. Effect of Financial Incentives on Breastfeeding: A Cluster Randomized Clinical Trial.

    Science.gov (United States)

    Relton, Clare; Strong, Mark; Thomas, Kate J; Whelan, Barbara; Walters, Stephen J; Burrows, Julia; Scott, Elaine; Viksveen, Petter; Johnson, Maxine; Baston, Helen; Fox-Rushby, Julia; Anokye, Nana; Umney, Darren; Renfrew, Mary J

    2018-02-05

    Although breastfeeding has a positive effect on an infant's health and development, the prevalence is low in many communities. The effect of financial incentives to improve breastfeeding prevalence is unknown. To assess the effect of an area-level financial incentive for breastfeeding on breastfeeding prevalence at 6 to 8 weeks post partum. The Nourishing Start for Health (NOSH) trial, a cluster randomized trial with 6 to 8 weeks follow-up, was conducted between April 1, 2015, and March 31, 2016, in 92 electoral ward areas in England with baseline breastfeeding prevalence at 6 to 8 weeks post partum less than 40%. A total of 10 010 mother-infant dyads resident in the 92 study electoral ward areas where the infant's estimated or actual birth date fell between February 18, 2015, and February 17, 2016, were included. Areas were randomized to the incentive plus usual care (n = 46) (5398 mother-infant dyads) or to usual care alone (n = 46) (4612 mother-infant dyads). Usual care was delivered by clinicians (mainly midwives, health visitors) in a variety of maternity, neonatal, and infant feeding services, all of which were implementing the UNICEF UK Baby Friendly Initiative standards. Shopping vouchers worth £40 (US$50) were offered to mothers 5 times based on infant age (2 days, 10 days, 6-8 weeks, 3 months, 6 months), conditional on the infant receiving any breast milk. The primary outcome was electoral ward area-level 6- to 8-week breastfeeding period prevalence, as assessed by clinicians at the routine 6- to 8-week postnatal check visit. Secondary outcomes were area-level period prevalence for breastfeeding initiation and for exclusive breastfeeding at 6 to 8 weeks. In the intervention (5398 mother-infant dyads) and control (4612 mother-infant dyads) group, the median (interquartile range) percentage of women aged 16 to 44 years was 36.2% (3.0%) and 37.4% (3.6%) years, respectively. After adjusting for baseline breastfeeding prevalence and local government

  4. Three-atom clusters

    International Nuclear Information System (INIS)

    Pen'kov, F.M.

    1998-01-01

    The Born-Oppenheimer approximation is used to obtain an equation for the effective interaction in three atoms bound by a single electron. For low binding energies in an 'electron + atom' pair, long-range forces arise between the atoms, leading to bound states when the size of the three-atom cluster is a few tens of angstrom. A system made of alkali-metal atoms is considered as an example

  5. Cost-effectiveness of nurse-led multifactorial care to prevent or postpone new disabilities in community-living older people : Results of a cluster randomized trial

    NARCIS (Netherlands)

    Suijker, Jacqueline J.; MacNeil-Vroomen, Janet L.; van Rijn, Marjon; Buurman, Bianca M.; de Rooij, Sophia E.; van Charente, Eric P. Moll; Bosmans, Judith E.

    2017-01-01

    Objective To evaluate the cost-effectiveness of nurse-led multifactorial care to prevent or postpone new disabilities in community-living older people in comparison with usual care. Methods We conducted cost-effectiveness and cost-utility analyses alongside a cluster randomized trial with one-year

  6. Cost-effectiveness of nurse-led multifactorial care to prevent or postpone new disabilities in community-living older people: Results of a cluster randomized trial

    NARCIS (Netherlands)

    Suijker, Jacqueline J.; MacNeil-Vroomen, Janet L.; van Rijn, Marjon; Buurman, Bianca M.; de Rooij, Sophia E.; Moll van Charante, Eric P.; Bosmans, Judith E.

    2017-01-01

    Objective To evaluate the cost-effectiveness of nurse-led multifactorial care to prevent or postpone new disabilities in community-living older people in comparison with usual care. Methods We conducted cost-effectiveness and cost-utility analyses alongside a cluster randomized trial with one-year

  7. Cost-effectiveness of nurse-led multifactorial care to prevent or postpone new disabilities in community-living older people : Results of a cluster randomized trial

    NARCIS (Netherlands)

    Suijker, Jacqueline J; MacNeil-Vroomen, Janet L; van Rijn, Marjon; Buurman, Bianca M; de Rooij, Sophia E; Moll van Charante, Eric P; Bosmans, Judith E

    2017-01-01

    OBJECTIVE: To evaluate the cost-effectiveness of nurse-led multifactorial care to prevent or postpone new disabilities in community-living older people in comparison with usual care. METHODS: We conducted cost-effectiveness and cost-utility analyses alongside a cluster randomized trial with one-year

  8. The Happy Life Club™ study protocol: A cluster randomised controlled trial of a type 2 diabetes health coach intervention

    Directory of Open Access Journals (Sweden)

    Yang Hui

    2011-02-01

    Full Text Available Abstract Background The Happy Life Club™ is an intervention that utilises health coaches trained in behavioural change and motivational interviewing techniques to assist with the management of type 2 diabetes mellitus (T2DM in primary care settings in China. Health coaches will support participants to improve modifiable risk factors and adhere to effective self-management treatments associated with T2DM. Methods/Design A cluster randomised controlled trial involving 22 Community Health Centres (CHCs in Fengtai District of Beijing, China. CHCs will be randomised into a control or intervention group, facilitating recruitment of at least 1320 individual participants with T2DM into the study. Participants in the intervention group will receive a combination of both telephone and face-to-face health coaching over 18 months, in addition to usual care received by the control group. Health coaching will be performed by CHC doctors and nurses certified in coach-assisted chronic disease management. Outcomes will be assessed at baseline and again at 6, 12 and 18 months by means of a clinical health check and self-administered questionnaire. The primary outcome measure is HbA1c level. Secondary outcomes include metabolic, physiological and psychological variables. Discussion This cluster RCT has been developed to suit the Chinese health care system and will contribute to the evidence base for the management of patients with T2DM. With a strong focus on self-management and health coach support, the study has the potential to be adapted to other chronic diseases, as well as other regions of China. Trial Registration Current Controlled Trials ISRCTN01010526

  9. Higgs Pair Production: Choosing Benchmarks With Cluster Analysis

    CERN Document Server

    Carvalho, Alexandra; Dorigo, Tommaso; Goertz, Florian; Gottardo, Carlo A.; Tosi, Mia

    2016-01-01

    New physics theories often depend on a large number of free parameters. The precise values of those parameters in some cases drastically affect the resulting phenomenology of fundamental physics processes, while in others finite variations can leave it basically invariant at the level of detail experimentally accessible. When designing a strategy for the analysis of experimental data in the search for a signal predicted by a new physics model, it appears advantageous to categorize the parameter space describing the model according to the corresponding kinematical features of the final state. A multi-dimensional test statistic can be used to gauge the degree of similarity in the kinematics of different models; a clustering algorithm using that metric may then allow the division of the space into homogeneous regions, each of which can be successfully represented by a benchmark point. Searches targeting those benchmark points are then guaranteed to be sensitive to a large area of the parameter space. In this doc...

  10. Effect of workplace- versus home-based physical exercise on pain in healthcare workers: study protocol for a single blinded cluster randomized controlled trial

    Science.gov (United States)

    2014-01-01

    Background The prevalence and consequences of musculoskeletal pain is considerable among healthcare workers, allegedly due to high physical work demands of healthcare work. Previous investigations have shown promising results of physical exercise for relieving pain among different occupational groups, but the question remains whether such physical exercise should be performed at the workplace or conducted as home-based exercise. Performing physical exercise at the workplace together with colleagues may be more motivating for some employees and thus increase adherence. On the other hand, physical exercise performed during working hours at the workplace may be costly for the employers in terms of time spend. Thus, it seems relevant to compare the efficacy of workplace- versus home-based training on musculoskeletal pain. This study is intended to investigate the effect of workplace-based versus home-based physical exercise on musculoskeletal pain among healthcare workers. Methods/Design This study was designed as a cluster randomized controlled trial performed at 3 hospitals in Copenhagen, Denmark. Clusters are hospital departments and hospital units. Cluster randomization was chosen to increase adherence and avoid contamination between interventions. Two hundred healthcare workers from 18 departments located at three different hospitals is allocated to 10 weeks of 1) workplace based physical exercise performed during working hours (using kettlebells, elastic bands and exercise balls) for 5 × 10 minutes per week and up to 5 group-based coaching sessions, or 2) home based physical exercise performed during leisure time (using elastic bands and body weight exercises) for 5 × 10 minutes per week. Both intervention groups will also receive ergonomic instructions on patient handling and use of lifting aides etc. Inclusion criteria are female healthcare workers working at a hospital. Average pain intensity (VAS scale 0-10) of the back, neck and shoulder

  11. Relative effectiveness of insulin pump treatment over multiple daily injections and structured education during flexible intensive insulin treatment for type 1 diabetes: cluster randomised trial (REPOSE).

    Science.gov (United States)

    2017-03-30

    Objective  To compare the effectiveness of insulin pumps with multiple daily injections for adults with type 1 diabetes, with both groups receiving equivalent training in flexible insulin treatment. Design  Pragmatic, multicentre, open label, parallel group, cluster randomised controlled trial (Relative Effectiveness of Pumps Over MDI and Structured Education (REPOSE) trial). Setting  Eight secondary care centres in England and Scotland. Participants  Adults with type 1 diabetes who were willing to undertake intensive insulin treatment, with no preference for pumps or multiple daily injections. Participants were allocated a place on established group training courses that taught flexible intensive insulin treatment ("dose adjustment for normal eating," DAFNE). The course groups (the clusters) were then randomly allocated in pairs to either pump or multiple daily injections. Interventions  Participants attended training in flexible insulin treatment (using insulin analogues) structured around the use of pump or injections, followed for two years. Main outcome measures  The primary outcomes were a change in glycated haemoglobin (HbA1c) values (%) at two years in participants with baseline HbA1c value of ≥7.5% (58 mmol/mol), and the proportion of participants achieving an HbA1c value of intention to treat analysis, of which 235 (119 pump and 116 injection) had baseline HbA1c values of ≥7.5%. Glycaemic control and rates of severe hypoglycaemia improved in both groups. The mean change in HbA1c at two years was -0.85% with pump treatment and -0.42% with multiple daily injections. Adjusting for course, centre, age, sex, and accounting for missing values, the difference was -0.24% (-2.7 mmol/mol) in favour of pump users (95% confidence interval -0.53 to 0.05, P=0.10). Most psychosocial measures showed no difference, but pump users showed greater improvement in treatment satisfaction and some quality of life domains (dietary freedom and daily hassle) at 12 and 24

  12. Outcomes of a pilot hand hygiene randomized cluster trial to reduce communicable infections among US office-based employees.

    Science.gov (United States)

    Stedman-Smith, Maggie; DuBois, Cathy L Z; Grey, Scott F; Kingsbury, Diana M; Shakya, Sunita; Scofield, Jennifer; Slenkovich, Ken

    2015-04-01

    To determine the effectiveness of an office-based multimodal hand hygiene improvement intervention in reducing self-reported communicable infections and work-related absence. A randomized cluster trial including an electronic training video, hand sanitizer, and educational posters (n = 131, intervention; n = 193, control). Primary outcomes include (1) self-reported acute respiratory infections (ARIs)/influenza-like illness (ILI) and/or gastrointestinal (GI) infections during the prior 30 days; and (2) related lost work days. Incidence rate ratios calculated using generalized linear mixed models with a Poisson distribution, adjusted for confounders and random cluster effects. A 31% relative reduction in self-reported combined ARI-ILI/GI infections (incidence rate ratio: 0.69; 95% confidence interval, 0.49 to 0.98). A 21% nonsignificant relative reduction in lost work days. An office-based multimodal hand hygiene improvement intervention demonstrated a substantive reduction in self-reported combined ARI-ILI/GI infections.

  13. Role of pn-pairs interaction in nuclear structure

    International Nuclear Information System (INIS)

    Nie, G.K.

    2004-01-01

    Full text: The nuclear structure approach is based on theory of interaction of pn-pairs with suggestion that proton and neutron of one pair have the same nuclear potential. In frame of this model nuclei with N=Z were analyzed in [1,2]. In [1] radii of position of last proton were estimated on difference of proton and neutron separation energies. In [2] a phenomenological formula for calculation of binding energy of alpha- cluster nuclei was found. Present work is devoted to developing the nuclear structure model. Coulomb energy of nuclei with N=Z has been found from sum of differences of separation energies of protons and neutrons belonging to one pairs. From analysis of nuclei 12 C and 16 O the value of energy of Coulomb repulsion between 2 α -clusters has been estimated equal to ε C α =1.925 MeV [3], which means that value of nuclear (meson) interaction between 2 α -clusters is expected to be ε m αα = ε cov αα + ε C α =4.350 MeV. From suggestion that energy of long range Coulomb repulsion is compensated by surface tension energy an equation has been found to calculate radius of position of last proton on value of Z. Charge radii of nuclei from 58 Ni to 208 Bi and further have been calculated with difference from experimental ones in several hundredths of fm. In the approach binding energy of excess neutrons stays beyond the consideration. Therefore, in calculation of binding energies of nuclei the experimental values of separation energies of excess neutrons are used. There is a good agreement between calculated values of binding energies of some isotopes of all known elements as well as separation energies of alpha particle and deuteron and experimental data. The difference from experimental binding energy in most of the cases is about 0.5% and less

  14. The Long-Term Effectiveness of a Selective, Personality-Targeted Prevention Program in Reducing Alcohol Use and Related Harms: A Cluster Randomized Controlled Trial

    Science.gov (United States)

    Newton, Nicola C.; Conrod, Patricia J.; Slade, Tim; Carragher, Natacha; Champion, Katrina E.; Barrett, Emma L.; Kelly, Erin V.; Nair, Natasha K.; Stapinski, Lexine; Teesson, Maree

    2016-01-01

    Background: This study investigated the long-term effectiveness of Preventure, a selective personality-targeted prevention program, in reducing the uptake of alcohol, harmful use of alcohol, and alcohol-related harms over a 3-year period. Methods: A cluster randomized controlled trial was conducted to assess the effectiveness of Preventure.…

  15. Effects of quality improvement in health facilities and community mobilization through women’s groups on maternal, neonatal and perinatal mortality in three districts of Malawi: MaiKhanda, a cluster randomized controlled effectiveness trial

    Science.gov (United States)

    Colbourn, Tim; Nambiar, Bejoy; Bondo, Austin; Makwenda, Charles; Tsetekani, Eric; Makonda-Ridley, Agnes; Msukwa, Martin; Barker, Pierre; Kotagal, Uma; Williams, Cassie; Davies, Ros; Webb, Dale; Flatman, Dorothy; Lewycka, Sonia; Rosato, Mikey; Kachale, Fannie; Mwansambo, Charles; Costello, Anthony

    2016-01-01

    Background Maternal, perinatal and neonatal mortality remains high in low-income countries. We evaluated community and facility-based interventions to reduce deaths in three districts of Malawi. Methods We evaluated a rural participatory women’s group community intervention (CI) and a quality improvement intervention at health centres (FI) via a two-by-two factorial cluster randomized controlled trial. Consenting pregnant women were followed-up to 2 months after birth using key informants. Primary outcomes were maternal, perinatal and neonatal mortality. Clusters were health centre catchment areas assigned using stratified computer-generated randomization. Following exclusions, including non-birthing facilities, 61 clusters were analysed: control (17 clusters, 4912 births), FI (15, 5335), CI (15, 5080) and FI + CI (14, 5249). This trial was registered as International Standard Randomised Controlled Trial [ISRCTN18073903]. Outcomes for 14 576 and 20 576 births were recorded during baseline (June 2007–September 2008) and intervention (October 2008–December 2010) periods. Results For control, FI, CI and FI + CI clusters neonatal mortality rates were 34.0, 28.3, 29.9 and 27.0 neonatal deaths per 1000 live births and perinatal mortality rates were 56.2, 55.1, 48.0 and 48.4 per 1000 births, during the intervention period. Adjusting for clustering and stratification, the neonatal mortality rate was 22% lower in FI + CI than control clusters (OR = 0.78, 95% CI 0.60–1.01), and the perinatal mortality rate was 16% lower in CI clusters (OR = 0.84, 95% CI 0.72–0.97). We did not observe any intervention effects on maternal mortality. Conclusions Despite implementation problems, a combined community and facility approach using participatory women’s groups and quality improvement at health centres reduced newborn mortality in rural Malawi. PMID:24030269

  16. Potential and limits to cluster-state quantum computing using probabilistic gates

    International Nuclear Information System (INIS)

    Gross, D.; Kieling, K.; Eisert, J.

    2006-01-01

    We establish bounds to the necessary resource consumption when building up cluster states for one-way computing using probabilistic gates. Emphasis is put on state preparation with linear optical gates, as the probabilistic character is unavoidable here. We identify rigorous general bounds to the necessary consumption of initially available maximally entangled pairs when building up one-dimensional cluster states with individually acting linear optical quantum gates, entangled pairs, and vacuum modes. As the known linear optics gates have a limited maximum success probability, as we show, this amounts to finding the optimal classical strategy of fusing pieces of linear cluster states. A formal notion of classical configurations and strategies is introduced for probabilistic nonfaulty gates. We study the asymptotic performance of strategies that can be simply described, and prove ultimate bounds to the performance of the globally optimal strategy. The arguments employ methods of random walks and convex optimization. This optimal strategy is also the one that requires the shortest storage time, and necessitates the fewest invocations of probabilistic gates. For two-dimensional cluster states, we find, for any elementary success probability, an essentially deterministic preparation of a cluster state with quadratic, hence optimal, asymptotic scaling in the use of entangled pairs. We also identify a percolation effect in state preparation, in that from a threshold probability on, almost all preparations will be either successful or fail. We outline the implications on linear optical architectures and fault-tolerant computations

  17. Variability in research ethics review of cluster randomized trials: a scenario-based survey in three countries

    Science.gov (United States)

    2014-01-01

    Background Cluster randomized trials (CRTs) present unique ethical challenges. In the absence of a uniform standard for their ethical design and conduct, problems such as variability in procedures and requirements by different research ethics committees will persist. We aimed to assess the need for ethics guidelines for CRTs among research ethics chairs internationally, investigate variability in procedures for research ethics review of CRTs within and among countries, and elicit research ethics chairs’ perspectives on specific ethical issues in CRTs, including the identification of research subjects. The proper identification of research subjects is a necessary requirement in the research ethics review process, to help ensure, on the one hand, that subjects are protected from harm and exploitation, and on the other, that reviews of CRTs are completed efficiently. Methods A web-based survey with closed- and open-ended questions was administered to research ethics chairs in Canada, the United States, and the United Kingdom. The survey presented three scenarios of CRTs involving cluster-level, professional-level, and individual-level interventions. For each scenario, a series of questions was posed with respect to the type of review required (full, expedited, or no review) and the identification of research subjects at cluster and individual levels. Results A total of 189 (35%) of 542 chairs responded. Overall, 144 (84%, 95% CI 79 to 90%) agreed or strongly agreed that there is a need for ethics guidelines for CRTs and 158 (92%, 95% CI 88 to 96%) agreed or strongly agreed that research ethics committees could be better informed about distinct ethical issues surrounding CRTs. There was considerable variability among research ethics chairs with respect to the type of review required, as well as the identification of research subjects. The cluster-cluster and professional-cluster scenarios produced the most disagreement. Conclusions Research ethics committees

  18. Efficacy and effectiveness of an rVSV-vectored vaccine expressing Ebola surface glycoprotein: interim results from the Guinea ring vaccination cluster-randomised trial.

    Science.gov (United States)

    Henao-Restrepo, Ana Maria; Longini, Ira M; Egger, Matthias; Dean, Natalie E; Edmunds, W John; Camacho, Anton; Carroll, Miles W; Doumbia, Moussa; Draguez, Bertrand; Duraffour, Sophie; Enwere, Godwin; Grais, Rebecca; Gunther, Stephan; Hossmann, Stefanie; Kondé, Mandy Kader; Kone, Souleymane; Kuisma, Eeva; Levine, Myron M; Mandal, Sema; Norheim, Gunnstein; Riveros, Ximena; Soumah, Aboubacar; Trelle, Sven; Vicari, Andrea S; Watson, Conall H; Kéïta, Sakoba; Kieny, Marie Paule; Røttingen, John-Arne

    2015-08-29

    A recombinant, replication-competent vesicular stomatitis virus-based vaccine expressing a surface glycoprotein of Zaire Ebolavirus (rVSV-ZEBOV) is a promising Ebola vaccine candidate. We report the results of an interim analysis of a trial of rVSV-ZEBOV in Guinea, west Africa. For this open-label, cluster-randomised ring vaccination trial, suspected cases of Ebola virus disease in Basse-Guinée (Guinea, west Africa) were independently ascertained by Ebola response teams as part of a national surveillance system. After laboratory confirmation of a new case, clusters of all contacts and contacts of contacts were defined and randomly allocated 1:1 to immediate vaccination or delayed (21 days later) vaccination with rVSV-ZEBOV (one dose of 2 × 10(7) plaque-forming units, administered intramuscularly in the deltoid muscle). Adults (age ≥18 years) who were not pregnant or breastfeeding were eligible for vaccination. Block randomisation was used, with randomly varying blocks, stratified by location (urban vs rural) and size of rings (≤20 vs >20 individuals). The study is open label and masking of participants and field teams to the time of vaccination is not possible, but Ebola response teams and laboratory workers were unaware of allocation to immediate or delayed vaccination. Taking into account the incubation period of the virus of about 10 days, the prespecified primary outcome was laboratory-confirmed Ebola virus disease with onset of symptoms at least 10 days after randomisation. The primary analysis was per protocol and compared the incidence of Ebola virus disease in eligible and vaccinated individuals in immediate vaccination clusters with the incidence in eligible individuals in delayed vaccination clusters. This trial is registered with the Pan African Clinical Trials Registry, number PACTR201503001057193. Between April 1, 2015, and July 20, 2015, 90 clusters, with a total population of 7651 people were included in the planned interim analysis. 48 of

  19. Mobile phone intervention reduces perinatal mortality in zanzibar: secondary outcomes of a cluster randomized controlled trial.

    Science.gov (United States)

    Lund, Stine; Rasch, Vibeke; Hemed, Maryam; Boas, Ida Marie; Said, Azzah; Said, Khadija; Makundu, Mkoko Hassan; Nielsen, Birgitte Bruun

    2014-03-26

    Mobile phones are increasingly used in health systems in developing countries and innovative technical solutions have great potential to overcome barriers of access to reproductive and child health care. However, despite widespread support for the use of mobile health technologies, evidence for its role in health care is sparse. We aimed to evaluate the association between a mobile phone intervention and perinatal mortality in a resource-limited setting. This study was a pragmatic, cluster-randomized, controlled trial with primary health care facilities in Zanzibar as the unit of randomization. At their first antenatal care visit, 2550 pregnant women (1311 interventions and 1239 controls) who attended antenatal care at selected primary health care facilities were included in this study and followed until 42 days after delivery. Twenty-four primary health care facilities in six districts were randomized to either mobile phone intervention or standard care. The intervention consisted of a mobile phone text message and voucher component. Secondary outcome measures included stillbirth, perinatal mortality, and death of a child within 42 days after birth as a proxy of neonatal mortality. Within the first 42 days of life, 2482 children were born alive, 54 were stillborn, and 36 died. The overall perinatal mortality rate in the study was 27 per 1000 total births. The rate was lower in the intervention clusters, 19 per 1000 births, than in the control clusters, 36 per 1000 births. The intervention was associated with a significant reduction in perinatal mortality with an odds ratio (OR) of 0.50 (95% CI 0.27-0.93). Other secondary outcomes showed an insignificant reduction in stillbirth (OR 0.65, 95% CI 0.34-1.24) and an insignificant reduction in death within the first 42 days of life (OR 0.79, 95% CI 0.36-1.74). Mobile phone applications may contribute to improved health of the newborn and should be considered by policy makers in resource-limited settings. ClinicalTrials

  20. Mental health first aid training for high school teachers: a cluster randomized trial

    Directory of Open Access Journals (Sweden)

    Jorm Anthony F

    2010-06-01

    Full Text Available Abstract Background Mental disorders often have their first onset during adolescence. For this reason, high school teachers are in a good position to provide initial assistance to students who are developing mental health problems. To improve the skills of teachers in this area, a Mental Health First Aid training course was modified to be suitable for high school teachers and evaluated in a cluster randomized trial. Methods The trial was carried out with teachers in South Australian high schools. Teachers at 7 schools received training and those at another 7 were wait-listed for future training. The effects of the training on teachers were evaluated using questionnaires pre- and post-training and at 6 months follow-up. The questionnaires assessed mental health knowledge, stigmatizing attitudes, confidence in providing help to others, help actually provided, school policy and procedures, and teacher mental health. The indirect effects on students were evaluated using questionnaires at pre-training and at follow-up which assessed any mental health help and information received from school staff, and also the mental health of the student. Results The training increased teachers' knowledge, changed beliefs about treatment to be more like those of mental health professionals, reduced some aspects of stigma, and increased confidence in providing help to students and colleagues. There was an indirect effect on students, who reported receiving more mental health information from school staff. Most of the changes found were sustained 6 months after training. However, no effects were found on teachers' individual support towards students with mental health problems or on student mental health. Conclusions Mental Health First Aid training has positive effects on teachers' mental health knowledge, attitudes, confidence and some aspects of their behaviour. Trial registration ACTRN12608000561381

  1. THE ASSEMBLY OF GALAXY CLUSTERS

    International Nuclear Information System (INIS)

    Berrier, Joel C.; Stewart, Kyle R.; Bullock, James S.; Purcell, Chris W.; Barton, Elizabeth J.; Wechsler, Risa H.

    2009-01-01

    We study the formation of 53 galaxy cluster-size dark matter halos (M = 10 14.0-14.76 M sun ) formed within a pair of cosmological Λ cold dark matter N-body simulations, and track the accretion histories of cluster subhalos with masses large enough to host ∼0.3 L * galaxies. By associating subhalos with cluster galaxies, we find the majority of galaxies in clusters experience no 'preprocessing' in the group environment prior to their accretion into the cluster. On average, 70% of cluster galaxies fall into the cluster potential directly from the field, with no luminous companions in their host halos at the time of accretion; less than 12% are accreted as members of groups with five or more galaxies. Moreover, we find that cluster galaxies are significantly less likely to have experienced a merger in the recent past (∼<6 Gyr) than a field halo of the same mass. These results suggest that local cluster processes such as ram pressure stripping, galaxy harassment, or strangulation play the dominant role in explaining the difference between cluster and field populations at a fixed stellar mass, and that pre-evolution or past merging in the group environment is of secondary importance for setting cluster galaxy properties for most clusters. The accretion times for z = 0 cluster members are quite extended, with ∼20% incorporated into the cluster halo more than 7 Gyr ago and ∼20% within the last 2 Gyr. By comparing the observed morphological fractions in cluster and field populations, we estimate an approximate timescale for late-type to early-type transformation within the cluster environment to be ∼6 Gyr.

  2. Structured patient handoff on an internal medicine ward: A cluster randomized control trial.

    Science.gov (United States)

    Tam, Penny; Nijjar, Aman P; Fok, Mark; Little, Chris; Shingina, Alexandra; Bittman, Jesse; Raghavan, Rashmi; Khan, Nadia A

    2018-01-01

    The effect of a multi-faceted handoff strategy in a high volume internal medicine inpatient setting on process and patient outcomes has not been clearly established. We set out to determine if a multi-faceted handoff intervention consisting of education, standardized handoff procedures, including fixed time and location for face-to-face handoff would result in improved rates of handoff compared with usual practice. We also evaluated resident satisfaction, health resource utilization and clinical outcomes. This was a cluster randomized controlled trial in a large academic tertiary care center with 18 inpatient internal medicine ward teams from January-April 2013. We randomized nine inpatient teams to an intervention where they received an education session standardizing who and how to handoff patients, with practice and feedback from facilitators. The control group of 9 teams continued usual non-standardized handoffs. The primary process outcome was the rate of patients handed over per 1000 patient nights. Other process outcomes included perceptions of inadequate handoff by overnight physicians, resource utilization overnight and hospital length of stay. Clinical outcomes included medical errors, frequency of patients requiring higher level of care overnight, and in-hospital mortality. The intervention group demonstrated a significant increase in the rate of patients handed over to the overnight physician (62.90/1000 person-nights vs. 46.86/1000 person-nights, p = 0.002). There was no significant difference in other process outcomes except resource utilization was increased in the intervention group (26.35/1000 person-days vs. 17.57/1000 person-days, p-value = 0.01). There was no significant difference between groups in medical errors (4.8% vs. 4.1%), need for higher level of care or in hospital mortality. Limitations include a dependence of accurate record keeping by the overnight physician, the possibility of cross-contamination in the handoff process, analysis at

  3. EHLS at School: school-age follow-up of the Early Home Learning Study cluster randomized controlled trial.

    Science.gov (United States)

    Westrupp, Elizabeth M; Bennett, Clair; Cullinane, Meabh; Hackworth, Naomi J; Berthelsen, Donna; Reilly, Sheena; Mensah, Fiona K; Gold, Lisa; Bennetts, Shannon K; Levickis, Penny; Nicholson, Jan M

    2018-05-02

    Targeted interventions during early childhood can assist families in providing strong foundations that promote children's health and wellbeing across the life course. There is growing recognition that longer follow-up times are necessary to assess intervention outcomes, as effects may change as children develop. The Early Home Learning Study, or 'EHLS', comprised two cluster randomized controlled superiority trials of a brief parenting intervention, smalltalk, aimed at supporting parents to strengthen the early childhood home learning environment of infants (6-12 months) or toddlers (12-36 months). Results showed sustained improvements in parent-child interactions and the home environment at the 32 week follow-up for the toddler but not the infant trial. The current study will therefore follow up the EHLS toddler cohort to primary school age, with the aim of addressing a gap in literature concerning long-term effects of early childhood interventions focused on improving school readiness and later developmental outcomes. 'EHLS at School' is a school-aged follow-up study of the toddler cluster randomized controlled trial (n = 1226). Data will be collected by parent-, child- and teacher-report questionnaires, recorded observations of parent-child interactions, and direct child assessment when children are aged 7.5 years old. Data linkage will provide additional data on child health and academic functioning at ages 5, 8 and 10 years. Child outcomes will be compared for families allocated to standard/usual care (control) versus those allocated to the smalltalk program (group program only or group program with additional home coaching). Findings from The Early Home Learning Study provided evidence of the benefits of the smalltalk intervention delivered via facilitated playgroups for parents of toddlers. The EHLS at School Study aims to examine the long-term outcomes of this initiative to determine whether improvements in the quality of the parent

  4. Protocol for a Cluster Randomised Controlled Trial to Compare the “Taste & See” Programme—A Church-Based Programme to Develop a Healthy Relationship with Food—With a Wait-List Control

    Directory of Open Access Journals (Sweden)

    Deborah Lycett

    2018-03-01

    Full Text Available (1 Background: Obesity is strongly associated with poor mental-health. Spiritual and religious wellbeing is associated with improved mental well-being and reduced emotional eating. “Taste & See”, a church based programme to help develop a healthy relationship with food has been successfully tested for feasibility in the UK but an adequately powered randomised controlled trial is needed to test efficacy. This paper reports on the protocol for such a trial; (2 Method: A cluster, randomised controlled trial where Christian churches (any denomination are the unit of randomisation. 150 overweight adults will be recruited from approximately 15 churches (clusters in the UK, each church (cluster will recruit approximately 10 participants. Churches will be randomised 2:1 to either begin the “Taste & See” programme immediately or in 10 weeks’ time. Data on eating habits, mental and spiritual health will be collected online before and after the intervention and control period and follow-up will continue until 2 years; (3 Implication of Results: Should the programme prove effective it will provide strong clinical evidence of the role of churches in improving the health and well-being of those struggling with food and weight issues.

  5. Effectiveness and implementation of an obesity prevention intervention: the HeLP-her Rural cluster randomised controlled trial.

    Science.gov (United States)

    Lombard, Catherine B; Harrison, Cheryce L; Kozica, Samantha L; Zoungas, Sophia; Keating, Catherine; Teede, Helena J

    2014-06-16

    To impact on the obesity epidemic, interventions that prevent weight gain across populations are urgently needed. However, even the most efficacious interventions will have little impact on obesity prevention unless they are successfully implemented in diverse populations and settings. Implementation research takes isolated efficacy studies into practice and policy and is particularly important in obesity prevention where there is an urgent need to accelerate the evidence to practice cycle. Despite the recognised need, few obesity prevention interventions have been implemented in real life settings and to our knowledge rarely target rural communities. Here we describe the rationale, design and implementation of a Healthy Lifestyle Program for women living in small rural communities (HeLP-her Rural). The primary goal of HeLP-her Rural is to prevent weight gain using a low intensity, self-management intervention. Six hundred women from 42 small rural communities in Australia will be randomised as clusters (n-21 control towns and n = 21 intervention towns). A pragmatic randomised controlled trial methodology will test efficacy and a comprehensive mixed methods community evaluation and cost analysis will inform effectiveness and implementation of this novel prevention program. Implementing population interventions to prevent obesity is complex, costly and challenging. To address these barriers, evidence based interventions need to move beyond isolated efficacy trials and report outcomes related to effectiveness and implementation. Large pragmatic trials provide an opportunity to inform both effectiveness and implementation leading to potential for greater impact at the population level. Pragmatic trials should incorporate both effectiveness and implementation outcomes and a multidimensional methodology to inform scale-up to population level. The learnings from this trial will impact on the design and implementation of population obesity prevention strategies

  6. Recruiting faith- and non-faith-based schools, adolescents and parents to a cluster randomised sexual-health trial: experiences, challenges and lessons from the mixed-methods Jack Feasibility Trial.

    Science.gov (United States)

    Aventin, Áine; Lohan, Maria; Maguire, Lisa; Clarke, Mike

    2016-07-29

    The move toward evidence-based education has led to increasing numbers of randomised trials in schools. However, the literature on recruitment to non-clinical trials is relatively underdeveloped, when compared to that of clinical trials. Recruitment to school-based randomised trials is, however, challenging, even more so when the focus of the study is a sensitive issue such as sexual health. This article reflects on the challenges of recruiting post-primary schools, adolescent pupils and parents to a cluster randomised feasibility trial of a sexual-health intervention, and the strategies employed to address them. The Jack Trial was funded by the UK National Institute for Health Research. It comprised a feasibility study of an interactive film-based sexual-health intervention entitled If I Were Jack, recruiting over 800 adolescents from eight socio-demographically diverse post-primary schools in Northern Ireland. It aimed to determine the facilitators and barriers to recruitment and retention to a school-based sexual-health trial and identify optimal multi-level strategies for an effectiveness study. As part of an embedded process evaluation, we conducted semi-structured interviews and focus groups with principals, vice-principals, teachers, pupils and parents recruited to the study as well as classroom observations and a parents' survey. With reference to social learning theory, we identified a number of individual-, behavioural- and environmental-level factors that influenced recruitment. Commonly identified facilitators included perceptions of the relevance and potential benefit of the intervention to adolescents, the credibility of the organisation and individuals running the study, support offered by trial staff, and financial incentives. Key barriers were prior commitment to other research, lack of time and resources, and perceptions that the intervention was incompatible with pupil or parent needs or the school ethos. Reflecting on the methodological

  7. Chromosomal clustering of a human transcriptome reveals regulatory background

    Directory of Open Access Journals (Sweden)

    Purmann Antje

    2005-09-01

    Full Text Available Abstract Background There has been much evidence recently for a link between transcriptional regulation and chromosomal gene order, but the relationship between genomic organization, regulation and gene function in higher eukaryotes remains to be precisely defined. Results Here, we present evidence for organization of a large proportion of a human transcriptome into gene clusters throughout the genome, which are partly regulated by the same transcription factors, share biological functions and are characterized by non-housekeeping genes. This analysis was based on the cardiac transcriptome identified by our genome-wide array analysis of 55 human heart samples. We found 37% of these genes to be arranged mainly in adjacent pairs or triplets. A significant number of pairs of adjacent genes are putatively regulated by common transcription factors (p = 0.02. Furthermore, these gene pairs share a significant number of GO functional classification terms. We show that the human cardiac transcriptome is organized into many small clusters across the whole genome, rather than being concentrated in a few larger clusters. Conclusion Our findings suggest that genes expressed in concert are organized in a linear arrangement for coordinated regulation. Determining the relationship between gene arrangement, regulation and nuclear organization as well as gene function will have broad biological implications.

  8. Electron-induced chemistry in microhydrated sulfuric acid clusters

    Science.gov (United States)

    Lengyel, Jozef; Pysanenko, Andriy; Fárník, Michal

    2017-11-01

    We investigate the mixed sulfuric acid-water clusters in a molecular beam experiment with electron attachment and negative ion mass spectrometry and complement the experiment by density functional theory (DFT) calculations. The microhydration of (H2SO4)m(H2O)n clusters is controlled by the expansion conditions, and the electron attachment yields the main cluster ion series (H2SO4)m(H2O)nHSO4- and (H2O)nH2SO4-. The mass spectra provide an experimental evidence for the onset of the ionic dissociation of sulfuric acid and ion-pair (HSO4- ṡ ṡ ṡ H3O+) formation in the neutral H2SO4(H2O)n clusters with n ≥ 5 water molecules, in excellent agreement with the theoretical predictions. In the clusters with two sulfuric acid molecules (H2SO4)2(H2O)n this process starts as early as n ≥ 2 water molecules. The (H2SO4)m(H2O)nHSO4- clusters are formed after the dissociative electron attachment to the clusters containing the (HSO4- ṡ ṡ ṡ H3O+) ion-pair structure, which leads to the electron recombination with the H3O+ moiety generating H2O molecule and the H-atom dissociation from the cluster. The (H2O)nH2SO4- cluster ions point to an efficient caging of the H atom by the surrounding water molecules. The electron-energy dependencies exhibit an efficient electron attachment at low electron energies below 3 eV, and no resonances above this energy, for all the measured mass peaks. This shows that in the atmospheric chemistry only the low-energy electrons can be efficiently captured by the sulfuric acid-water clusters and converted into the negative ions. Possible atmospheric consequences of the acidic dissociation in the clusters and the electron attachment to the sulfuric acid-water aerosols are discussed.

  9. A redox-switchable Au8-cluster sensor.

    Science.gov (United States)

    Wu, Te-Haw; Hsu, Yu-Yen; Lin, Shu-Yi

    2012-07-09

    The proof of concept of a simple sensing platform based on the fluorescence of a gold cluster consisting of eight atoms, which is easily manipulated by reduction and oxidation of a specific molecule in the absence of chemical linkers, is demonstrated. Without using any coupling reagents to arrange the distance of the donor-acceptor pair, the fluorescence of the Au(8) -cluster is immediately switched off in the presence of 2-pyridinethiol (2-PyT) quencher. Through an upward-curving Stern-Volmer plot, the system shows complex fluorescence quenching with a combination of static and dynamic quenching processes. To analyze the static quenching constant (V) by a "sphere of action" model, the collisional encounter between the Au(8) -cluster and 2-PyT presents a quenching radius (r) ≈5.8 nm, which is larger than the sum of the radii of the Au(8) -cluster and 2-PyT. This implies that fluorescence quenching can occur even though the Au(8) -cluster and 2-PyT are not very close to each other. The quenching pathway may be derived from a photoinduced electron-transfer process of the encounter pair between the Au(8) -cluster (as an electron donor) and 2-PyT (as an electron acceptor) to allow efficient fluorescence quenching in the absence of coupling reagents. Interestingly, the fluorescence is restored by oxidation of 2-PyT to form the corresponding disulfide compound and then quenched again after the reduction of the disulfide. This redox-switchable fluorescent Au(8) -cluster platform is a novel discovery, and its utility as a promising sensor for detecting H(2) O(2) -generating enzymatic transformations is demonstrated. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Effect on the process of care of an active strategy to implement clinical guidelines on physiotherapy for low back pain: a cluster randomised controlled trial

    NARCIS (Netherlands)

    Bekkering, G.E.; Hendriks, H.J.M.; Tulder, van M.; Knol, D.L.; Hoeijenbos, M.; Oostendorp, R.A.B.; Bouter, L.M.

    2005-01-01

    OBJECTIVES: To evaluate the effect on the process of care of an active strategy to implement clinical guidelines on physiotherapy for low back pain. DESIGN: A cluster randomised controlled trial comparing an active strategy with standard dissemination. SETTING: Primary care physiotherapy practices.

  11. Menstruation and the Cycle of Poverty: A Cluster Quasi-Randomised Control Trial of Sanitary Pad and Puberty Education Provision in Uganda

    Science.gov (United States)

    Montgomery, Paul; Hennegan, Julie; Dolan, Catherine; Wu, Maryalice; Steinfield, Laurel; Scott, Linda

    2016-01-01

    Background Poor menstrual knowledge and access to sanitary products have been proposed as barriers to menstrual health and school attendance. In response, interventions targeting these needs have seen increasing implementation in public and private sectors. However, there has been limited assessment of their effectiveness. Objectives Assess the impact of providing reusable sanitary pads and puberty education on girls’ school attendance and psychosocial wellbeing outcomes. Methods A cluster quasi-randomised controlled trial was conducted across 8 schools, including 1124 girls, in rural Uganda. Schools were allocated to one of four conditions: the provision of puberty education alone; reusable sanitary pads alone; puberty education and reusable sanitary pads; and a control (no intervention). The primary outcome was school attendance. Secondary outcomes reflected psychosocial wellbeing. Results At follow-up, school attendance had worsened for girls across all conditions. Per-protocol analysis revealed that this decline was significantly greater for those in the control condition d = 0.52 (95%CI 0.26–0.77), with those in control schools having a 17.1% (95%CI: 8.7–25.5) greater drop in attendance than those in any intervention school. There were no differences between the intervention conditions. High rates of school drop-out and transfer meant the trial suffered from substantial participant drop-out. Intention-to-treat analyses using two different imputation strategies were consistent with the main results, with mean differences of 5.2% attendance in best-case and 24.5% in worst-case imputations. Results were robust to adjustments for clustering. There was no impact of the interventions on girls’ self-reported shame or insecurity during menstruation. Conclusion Results of the trial support the hypothesised positive impact of providing sanitary pads or puberty education for girls’ school attendance in a developing country context. Findings must be interpreted

  12. A cluster randomized trial of strategies to increase uptake amongst young women invited for their first cervical screen: The STRATEGIC trial.

    Science.gov (United States)

    Kitchener, H; Gittins, M; Cruickshank, M; Moseley, C; Fletcher, S; Albrow, R; Gray, A; Brabin, L; Torgerson, D; Crosbie, E J; Sargent, A; Roberts, C

    2018-06-01

    Objectives To measure the feasibility and effectiveness of interventions to increase cervical screening uptake amongst young women. Methods A two-phase cluster randomized trial conducted in general practices in the NHS Cervical Screening Programme. In Phase 1, women in practices randomized to intervention due for their first invitation to cervical screening received a pre-invitation leaflet and, separately, access to online booking. In Phase 2, non-attenders at six months were randomized to one of: vaginal self-sample kits sent unrequested or offered; timed appointments; nurse navigator; or the choice between nurse navigator or self-sample kits. Primary outcome was uplift in intervention vs. control practices, at 3 and 12 months post invitation. Results Phase 1 randomized 20,879 women. Neither pre-invitation leaflet nor online booking increased screening uptake by three months (18.8% pre-invitation leaflet vs. 19.2% control and 17.8% online booking vs. 17.2% control). Uptake was higher amongst human papillomavirus vaccinees at three months (OR 2.07, 95% CI 1.69-2.53, p < 0.001). Phase 2 randomized 10,126 non-attenders, with 32-34 clusters for each intervention and 100 clusters as controls. Sending self-sample kits increased uptake at 12 months (OR 1.51, 95% CI 1.20-1.91, p = 0.001), as did timed appointments (OR 1.41, 95% CI 1.14-1.74, p = 0.001). The offer of a nurse navigator, a self-sample kits on request, and choice between timed appointments and nurse navigator were ineffective. Conclusions Amongst non-attenders, self-sample kits sent and timed appointments achieved an uplift in screening over the short term; longer term impact is less certain. Prior human papillomavirus vaccination was associated with increased screening uptake.

  13. Parenting for Lifelong Health: a pragmatic cluster randomised controlled trial of a non-commercialised parenting programme for adolescents and their families in South Africa

    Science.gov (United States)

    Cluver, Lucie D; Meinck, Franziska; Steinert, Janina I; Shenderovich, Yulia; Doubt, Jenny; Herrero Romero, Rocio; Lombard, Carl J; Redfern, Alice; Ward, Catherine L; Tsoanyane, Sibongile; Nzima, Divane; Sibanda, Nkosiyapha; Wittesaele, Camille; De Stone, Sachin; Boyes, Mark E; Catanho, Ricardo; Lachman, Jamie McLaren; Salah, Nasteha; Nocuza, Mzuvukile; Gardner, Frances

    2018-01-01

    Objective To assess the impact of ‘Parenting for Lifelong Health: Sinovuyo Teen’, a parenting programme for adolescents in low-income and middle-income countries, on abuse and parenting practices. Design Pragmatic cluster randomised controlled trial. Setting 40 villages/urban sites (clusters) in the Eastern Cape province, South Africa. Participants 552 families reporting conflict with their adolescents (aged 10–18). Intervention Intervention clusters (n=20) received a 14-session parent and adolescent programme delivered by trained community members. Control clusters (n=20) received a hygiene and hand-washing promotion programme. Main outcome measures Primary outcomes: abuse and parenting practices at 1 and 5–9 months postintervention. Secondary outcomes: caregiver and adolescent mental health and substance use, adolescent behavioural problems, social support, exposure to community violence and family financial well-being at 5–9 months postintervention. Blinding was not possible. Results At 5–9 months postintervention, the intervention was associated with lower abuse (caregiver report incidence rate ratio (IRR) 0.55 (95% CI 0.40 to 0.75, Pcorporal punishment (caregiver report IRR=0.55 (95% CI 0.37 to 0.83, P=0.004)); improved positive parenting (caregiver report d=0.25 (95% CI 0.03 to 0.47, P=0.024)), involved parenting (caregiver report d=0.86 (95% CI 0.64 to 1.08, Pcorporal punishment IRR=1.05 (95% CI 0.70 to 1.57, P=0.819). Secondary outcomes showed reductions in caregiver corporal punishment endorsement, mental health problems, parenting stress, substance use and increased social support (all caregiver report). Intervention adolescents reported no differences in mental health, behaviour or community violence, but had lower substance use (all adolescent report). Intervention families had improved economic welfare, financial management and more violence avoidance planning (in caregiver and adolescent report). No adverse effects were detected

  14. Silence is deadly: a cluster-randomised controlled trial of a mental health help-seeking intervention for young men.

    Science.gov (United States)

    Calear, Alison L; Banfield, Michelle; Batterham, Philip J; Morse, Alyssa R; Forbes, Owen; Carron-Arthur, Bradley; Fisk, Martin

    2017-10-23

    Young men are consistently less likely to seek help for mental health problems than their female peers. This is particularly concerning given the high rates of suicide among male adolescents. The school system has been identified as an ideal setting for the implementation of prevention and early intervention programs for young people. The current trial aims to determine the effectiveness of the Silence is Deadly program in increasing positive help-seeking intentions for mental health problems and suicide among male secondary school students. This study is a two-arm, cluster-randomised, controlled trial that will compare the Silence is Deadly program to a wait-list control condition. Eight Australian high schools will be recruited to the trial, with male students in grades 11 and 12 (16 to 18 years of age) targeted for participation. The program is an innovative male-tailored suicide prevention intervention, comprising a presentation that emphasises role-modelling and legitimises help-seeking for personal and emotional problems, and a brief video that features celebrity athletes who counter existing male norms around help-seeking and encourage communication about personal and emotional issues. The program also includes a discussion of how to help a friend in distress and ends with a question and answer session. The primary outcome measure for the current study is help-seeking intentions. Secondary outcomes include help-seeking behaviour, help-seeking attitudes, help-seeking stigma, mental health symptoms, and suicidal ideation. Data will be collected pre-intervention, post-intervention, and at 3-month follow-up. Primary analyses will compare changes in help-seeking intentions for the intervention condition relative to the wait-list control condition using mixed-effects repeated-measures analyses that account for clustering within schools. If proven to be effective, this targeted help-seeking intervention for adolescent males, which is currently only delivered in

  15. Does training family physicians in shared decision making promote optimal use of antibiotics for acute respiratory infections? Study protocol of a pilot clustered randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Côté Luc

    2007-11-01

    Full Text Available Abstract Background In North America, although it varies according to the specific type of acute respiratory infections (ARI, use of antibiotics is estimated to be well above the expected prevalence of bacterial infections. The objective of this pilot clustered randomized controlled trial (RCT is to assess the feasibility of a larger clustered RCT aiming at evaluating the impact of DECISION+, a continuing professional development (CPD program in shared decision making, on the optimal use of antibiotics in the context of ARI. Methods/design This pilot study is a cluster RCT conducted with family physicians from Family Medicine Groups (FMG in the Quebec City area, Canada. Participating FMG are randomised to an immediate DECISION+ group, a CPD program in shared decision making, (experimental group, or a delayed DECISION+ group (control group. Data collection involves recruiting five patients consulting for ARI per physician from both study groups before (Phase 1 and after (Phase 2 exposure of the experimental group to the DECISION+ program, and after exposure of the control group to the DECISION+ program (Phase 3. The primary outcome measures to assess the feasibility of a larger RCT include: 1 proportion of contacted FMG that agree to participate; 2 proportion of recruited physicians who participate in the DECISION+ program; 3 level of satisfaction of physicians regarding DECISION+; and 4 proportion of missing data in each data collection phase. Levels of agreement of the patient-physician dyad on the Decisional Conflict Scale and physicians' prescription profile for ARI are performed as secondary outcome measures. Discussion This study protocol is informative for researchers and clinicians interested in designing and/or conducting clustered RCT with FMG regarding training of physicians in shared decision making. Trial Registration ClinicalTrials.gov Identifier: NCT00354315

  16. Effectiveness of school dental screening on dental visits and untreated caries among primary schoolchildren: study protocol for a cluster randomised controlled trial.

    Science.gov (United States)

    Alayadi, Haya; Sabbah, Wael; Bernabé, Eduardo

    2018-04-13

    Dental caries is one of the most common diseases affecting children in Saudi Arabia despite the availability of free dental services. School-based dental screening could be a potential intervention that impacts uptake of dental services, and subsequently, dental caries' levels. The purpose of this study is to evaluate the effectiveness of two alternative approaches for school-based dental screening in promoting dental attendance and reducing untreated dental caries among primary schoolchildren. This is a cluster randomised controlled trial comparing referral of screened-positive children to a specific treatment facility (King Saud University Dental College) against conventional referral (information letter advising parents to take their child to a dentist). A thousand and ten children in 16 schools in Riyadh, Saudi Arabia, will be recruited for the trial. Schools (clusters) will be randomly selected and allocated to either group. Clinical assessment for dental caries will be conducted at baseline and after 12 months by dentists using the World Health Organisation (WHO) criteria. Data on sociodemographic, behavioural factors and children's dental visits will be collected through structured questionnaires at baseline and follow-up. The primary outcome is the change in number of teeth with untreated dental caries 12 months after referral. Secondary outcomes are the changes in the proportions of children having untreated caries and of those who visited the dentist over the trial period. This project should provide high level of evidence on the clinical benefits of school dental screening. The findings should potentially inform policies related to the continuation/implementation of school-based dental screening in Saudi Arabia. ClinicalTrials.gov , ID: NCT03345680 . Registered on 17 November 2017.

  17. Change in cardiovascular risk factors following early diagnosis of type 2 diabetes: a cohort analysis of a cluster-randomised trial

    OpenAIRE

    Black, James A; Sharp, Stephen J; Wareham, Nicholas J; Sandbæk, Annelli; Rutten, Guy EHM; Lauritzen, Torsten; Khunti, Kamlesh; Davies, Melanie J; Borch-Johnsen, Knut; Griffin, Simon J; Simmons, Rebecca K

    2014-01-01

    Background There is little evidence to inform the targeted treatment of individuals found early in the diabetes disease trajectory. Aim To describe cardiovascular disease (CVD) risk profiles and treatment of individual CVD risk factors by modelled CVD risk at diagnosis; changes in treatment, modelled CVD risk, and CVD risk factors in the 5 years following diagnosis; and how these are patterned by socioeconomic status. Design and setting Cohort analysis of a cluster-randomised trial (ADDITION-...

  18. A participatory parent-focused intervention promoting physical activity in preschools: design of a cluster-randomized trial

    Directory of Open Access Journals (Sweden)

    Hoffmann Kristina

    2010-01-01

    Full Text Available Abstract Background With rates of childhood obesity increasing, physical activity (PA promotion especially in young children has assumed greater importance. Given the limited effectiveness of most interventions to date, new approaches are needed. The General Systems theory suggests that involving parents as intervention targets may be effective in fostering healthier life styles in children. We describe the development of a parent-focused participatory intervention and the procedures used to evaluate its effectiveness in increasing daily PA in preschoolers. Methods/Design Thirty-seven South German preschools were identified for this study and agreed to participate. Using a two-armed, controlled cluster-randomized trial design we test a participatory intervention with parents as the primary target group and potential agents of behavioural change. Specifically, the intervention is designed to engage parents in the development, refinement and selection of project ideas to promote PA and in incorporating these ideas into daily routines within the preschool community, consisting of children, teachers and parents. Our study is embedded within an existing state-sponsored programme providing structured gym lessons to preschool children. Thus, child-based PA outcomes from the study arm with the parent-focused intervention and the state-sponsored programme are compared with those from the study arm with the state-sponsored programme alone. The evaluation entails baseline measurements of study outcomes as well as follow-up measurements at 6 and 12 months. Accelerometry measures PA intensity over a period of six days, with the mean over six days used as the primary outcome measure. Secondary outcomes include childrens' BMI, a sum of averaged skin fold thickness measurements across multiple sites, and PA behaviour. Longitudinal multilevel models are used to assess within-subject change and between-group differences in study outcomes, adjusted for covariates

  19. Impact of preoperative patient education on the prevention of postoperative complications after major visceral surgery: the cluster randomized controlled PEDUCAT trial.

    Science.gov (United States)

    Klaiber, Ulla; Stephan-Paulsen, Lisa M; Bruckner, Thomas; Müller, Gisela; Auer, Silke; Farrenkopf, Ingrid; Fink, Christine; Dörr-Harim, Colette; Diener, Markus K; Büchler, Markus W; Knebel, Phillip

    2018-05-24

    The prevention of postoperative complications is of prime importance after complex elective abdominal operations. Preoperative patient education may prevent postoperative complications and improve patients' wellbeing, but evidence for its efficacy is poor. The aims of the PEDUCAT trial were (a) to assess the impact of preoperative patient education on postoperative complications and patient-reported outcomes in patients scheduled for elective complex visceral surgery and (b) to evaluate the feasibility of cluster randomization in this setting. Adult patients (age ≥ 18 years) scheduled for elective major visceral surgery were randomly assigned in clusters to attend a preoperative education seminar or to the control group receiving the department's standard care. Outcome measures were the postoperative complications pneumonia, deep vein thrombosis (DVT), pulmonary embolism, burst abdomen, and in-hospital fall, together with patient-reported outcomes (postoperative pain, anxiety and depression, patient satisfaction, quality of life), length of hospital stay (LOS), and postoperative mortality within 30 days after the index operation. Statistical analysis was primarily by intention to treat. In total 244 patients (60 clusters) were finally included (intervention group 138 patients; control group 106 patients). Allocation of hospital wards instead of individual patients facilitated study conduct and reduced confusion about group assignment. In the intervention and control groups respectively, pneumonia occurred in 7.4% versus 8.3% (p = 0.807), pulmonary embolism in 1.6% versus 1.0% (p = 0.707), burst abdomen in 4.2% versus 1.0% (p = 0.165), and in-hospital falls in 0.0% versus 4.2% of patients (p = 0.024). DVT did not occur in any of the patients. Mortality rates (1.4% versus 1.9%, p = 0.790) and LOS (14.2 (+/- 12.0) days versus 16.1 (+/- 15.0) days, p = 0.285) were also similar in the intervention and control groups. Cluster

  20. Testing a workplace physical activity intervention: a cluster randomized controlled trial.

    Science.gov (United States)

    McEachan, Rosemary R C; Lawton, Rebecca J; Jackson, Cath; Conner, Mark; Meads, David M; West, Robert M

    2011-04-11

    Increased physical activity levels benefit both an individuals' health and productivity at work. The purpose of the current study was to explore the impact and cost-effectiveness of a workplace physical activity intervention designed to increase physical activity levels. A total of 1260 participants from 44 UK worksites (based within 5 organizations) were recruited to a cluster randomized controlled trial with worksites randomly allocated to an intervention or control condition. Measurement of physical activity and other variables occurred at baseline, and at 0 months, 3 months and 9 months post-intervention. Health outcomes were measured during a 30 minute health check conducted in worksites at baseline and 9 months post intervention. The intervention consisted of a 3 month tool-kit of activities targeting components of the Theory of Planned Behavior, delivered in-house by nominated facilitators. Self-reported physical activity (measured using the IPAQ short-form) and health outcomes were assessed. Multilevel modelling found no significant effect of the intervention on MET minutes of activity (from the IPAQ) at any of the follow-up time points controlling for baseline activity. However, the intervention did significantly reduce systolic blood pressure (B=-1.79 mm/Hg) and resting heart rate (B=-2.08 beats) and significantly increased body mass index (B=.18 units) compared to control. The intervention was found not to be cost-effective, however the substantial variability round this estimate suggested that further research is warranted. The current study found mixed support for this worksite physical activity intervention. The paper discusses some of the tensions involved in conducting rigorous evaluations of large-scale randomized controlled trials in real-world settings. © 2011 McEachan et al; licensee BioMed Central Ltd.

  1. Study protocol for a multi-component kindergarten-based intervention to promote healthy diets in toddlers: a cluster randomized trial

    Directory of Open Access Journals (Sweden)

    Sissel H. Helland

    2016-03-01

    Full Text Available Abstract Background There is concern about the lack of diversity in children’s diets, particularly low intakes of fruit and vegetables and high intakes of unhealthy processed food. This may be a factor in the rising prevalence of obesity. A reason for the lack of diversity in children’s diets may be food neophobia. This study aimed to promote a healthy and varied diet among toddlers in kindergarten. The primary objectives were to reduce food neophobia in toddlers, and promote healthy feeding practices among kindergarten staff and parents. Secondary objectives were to increase food variety in toddlers’ diets and reduce future overweight and obesity in these children. Methods This is an ongoing, cluster randomized trial. The intervention finished in 2014, but follow-up data collection is not yet complete. Eighteen randomly selected kindergartens located in two counties in Norway with enrolled children born in 2012 participated in the intervention. The kindergartens were matched into pairs based on background information, and randomly assigned to the intervention or control groups. A 9-week multi-component intervention was implemented, with four main elements: 1 kindergarten staff implemented a pedagogical tool (Sapere method in daily sessions to promote willingness to try new food; 2 kindergarten staff prepared and served the toddlers a cooked lunch from a menu corresponding to the pedagogical sessions; 3 kindergarten staff were encouraged to follow 10 meal principles on modeling, responsive feeding, repeated exposure, and enjoyable meals; and 4 parents were encouraged to read information and apply relevant feeding practices at home. The control group continued their usual practices. Preference taste tests were conducted to evaluate behavioral food neophobia, and children’s height and weight were measured. Parents and staff completed questionnaires before and after the intervention. Data have not yet been analyzed. Discussion This study

  2. Cluster randomised controlled trial of a financial incentive for mothers to improve breast feeding in areas with low breastfeeding rates: the NOSH study protocol.

    Science.gov (United States)

    Relton, Clare; Strong, Mark; Renfrew, Mary J; Thomas, Kate; Burrows, Julia; Whelan, Barbara; Whitford, Heather M; Scott, Elaine; Fox-Rushby, Julia; Anoyke, Nana; Sanghera, Sabina; Johnson, Maxine; Easton, Sue; Walters, Stephen

    2016-04-11

    Breast feeding can promote positive long-term and short-term health outcomes in infant and mother. The UK has one of the lowest breastfeeding rates (duration and exclusivity) in the world, resulting in preventable morbidities and associated healthcare costs. Breastfeeding rates are also socially patterned, thereby potentially contributing to health inequalities. Financial incentives have been shown to have a positive effect on health behaviours in previously published studies. Based on data from earlier development and feasibility stages, a cluster (electoral ward) randomised trial with mixed-method process and content evaluation was designed. The 'Nourishing Start for Health' (NOSH) intervention comprises a financial incentive programme of up to 6 months duration, delivered by front-line healthcare professionals, in addition to existing breastfeeding support. The intervention aims to increase the prevalence and duration of breast feeding in wards with low breastfeeding rates. The comparator is usual care (no offer of NOSH intervention). Routine data on breastfeeding rates at 6-8 weeks will be collected for 92 clusters (electoral wards) on an estimated 10,833 births. This sample is calculated to provide 80% power in determining a 4% point difference in breastfeeding rates between groups. Content and process evaluation will include interviews with mothers, healthcare providers, funders and commissioners of infant feeding services. The economic analyses, using a healthcare provider's perspective, will be twofold, including a within-trial cost-effectiveness analysis and beyond-trial modelling of longer term expectations for cost-effectiveness. Results of economic analyses will be expressed as cost per percentage point change in cluster level in breastfeeding rates between trial arms. In addition, we will present difference in resource use impacts for a range of acute conditions in babies aged 0-6 months. Participating organisations Research and Governance

  3. From Globular Clusters to Tidal Dwarfs: Structure Formation in the Tidal Tails of Merging Pairs

    Science.gov (United States)

    Knierman, K. A.; Gallagher, S. C.; Charlton, J. C.; Hunsberger, S. D.; Whitmore, B. C.; Kundu, A.; Hibbard, J. E.; Zaritsky, D. F.

    2001-05-01

    Using V and I images obtained with the Wide Field Planetary Camera 2 (WFPC2) of the Hubble Space Telescope, we investigate compact stellar structures within tidal tails. Six regions of tidal debris in the four classic ``Toomre Sequence'' mergers: NGC 4038/9 (``Antennae''), NGC 3256, NGC 3921, and NGC 7252 (``Atoms for Peace'') have been studied in order to explore how the star formation depends upon the local and global physical conditions. These mergers sample a range of stages in the evolutionary sequence, and include HI--rich and HI--poor environments. The six tails are found to contain a variety of stellar structures, with sizes ranging from those of globular clusters up to those of dwarf galaxies. From V and I WFPC2 images, we measure the luminosities and colors of the star clusters. NGC 3256 is found to have a large population of young clusters lying along both tails, similar to those found in the inner region of the merger. In contrast, NGC 4038/9 has no clusters in the observed region of the tail, only less luminous point sources likely to be individual stars. NGC 3921 and NGC 7252 have small populations of clusters that are concentrated in certain regions of the tail, and particularly in the prominent tidal dwarfs in the eastern and western tails of NGC 7252. The two cluster--rich tails of NGC 3256 are not distinguished from the others by their ages or by their total HI masses. We acknowledge support from NASA through STScI, and from NSF for an REU supplement for Karen Knierman.

  4. Electronic and atomic structure of the AlnHn+2 clusters

    DEFF Research Database (Denmark)

    Martinez, Jose Ignacio; Alonso, J.A.

    2008-01-01

    The electronic and atomic structure of the family of hydrogenated Al clusters AlnHn+2 with n=4-11 has been studied using the density functional theory with the generalized gradient approximation (GGA) for exchange and correlation. All these clusters have substantial gaps between the highest...... a polyhedron of n vertices and n H atoms form strong H-Al terminal bonds; one pair of electrons is involved in each of those bonds. The remaining n+1 electron pairs form a delocalized cloud over the surface of the Al cage. The clusters fulfilling the Wade-Mingos rule have wider HOMO-LUMO gaps...... and are chemically more stable. The trends in the gap have some reflections in the form of the photoabsorption spectra, calculated in the framework of time-dependent density functional theory using the GGA single-particle energies and orbitals and a local density approximation exchange-correlation kernel....

  5. Group hypnosis vs. relaxation for smoking cessation in adults: a cluster-randomised controlled trial

    Science.gov (United States)

    2013-01-01

    Background Despite the popularity of hypnotherapy for smoking cessation, the efficacy of this method is unclear. We aimed to investigate the efficacy of a single-session of group hypnotherapy for smoking cessation compared to relaxation in Swiss adult smokers. Methods This was a cluster-randomised, parallel-group, controlled trial. A single session of hypnosis or relaxation for smoking cessation was delivered to groups of smokers (median size = 11). Participants were 223 smokers consuming ≥ 5 cigarettes per day, willing to quit and not using cessation aids (47.1% females, M = 37.5 years [SD = 11.8], 86.1% Swiss). Nicotine withdrawal, smoking abstinence self-efficacy, and adverse reactions were assessed at a 2-week follow-up. The main outcome, self-reported 30-day point prevalence of smoking abstinence, was assessed at a 6-month follow up. Abstinence was validated through salivary analysis. Secondary outcomes included number of cigarettes smoked per day, smoking abstinence self-efficacy, and nicotine withdrawal. Results At the 6-month follow up, 14.7% in the hypnosis group and 17.8% in the relaxation group were abstinent. The intervention had no effect on smoking status (p = .73) or on the number of cigarettes smoked per day (p = .56). Smoking abstinence self-efficacy did not differ between the interventions (p = .14) at the 2-week follow-up, but non-smokers in the hypnosis group experienced reduced withdrawal (p = .02). Both interventions produced few adverse reactions (p = .81). Conclusions A single session of group hypnotherapy does not appear to be more effective for smoking cessation than a group relaxation session. Trial registration Current Controlled Trials ISRCTN72839675. PMID:24365274

  6. Community engagement and integrated health and polio immunisation campaigns in conflict-affected areas of Pakistan: a cluster randomised controlled trial.

    Science.gov (United States)

    Habib, Muhammad Atif; Soofi, Sajid; Cousens, Simon; Anwar, Saeed; Haque, Najib Ul; Ahmed, Imran; Ali, Noshad; Tahir, Rehman; Bhutta, Zulfiqar A

    2017-06-01

    Pakistan faces huge challenges in eradicating polio due to widespread poliovirus transmission and security challenges. Innovative interventions are urgently needed to strengthen community buy-in, to increase the coverage of oral polio vaccine (OPV) and other routine immunisations, and to enhance immunity through the introduction of inactivated polio vaccine (IPV) in combination with OPV. We aimed to evaluate the acceptability and effect on immunisation coverage of an integrated strategy for community engagement and maternal and child health immunisation campaigns in insecure and conflict-affected polio-endemic districts of Pakistan. We did a community-based three-arm cluster randomised trial in healthy children aged 1 month to 5 years that resided within the study sites in three districts of Pakistan at high risk of polio. Clusters were randomly assigned by a computer algorithm using restricted randomisation in blocks of 20 by an external statistician (1:1:1) to receive routine polio programme activities (control, arm A), additional interventions with community outreach and mobilisation using an enhanced communication package and provision of short-term preventive maternal and child health services and routine immunisation (health camps), including OPV (arm B), or all interventions of arm B with additional provision of IPV delivered at the maternal and child health camps (arm C). An independent team conducted surveys at baseline, endline, and after each round of supplementary immunisation activity for acceptability and effect. The primary outcome measures for the study were coverage of OPV, IPV, and routine extended programme on immunisation vaccines and changes in the proportion of unvaccinated and fully vaccinated children. This trial is registered with ClinicalTrials.gov, number NCT01908114. Between June 4, 2013, and May 31, 2014, 387 clusters were randomised (131 to arm A, 127 to arm B, and 129 to arm C). At baseline, 28 760 children younger than 5 years were

  7. Effects of improved sanitation on diarrheal reduction for children under five in Idiofa, DR Congo: a cluster randomized trial.

    Science.gov (United States)

    Cha, Seungman; Lee, JaeEun; Seo, DongSik; Park, Byoung Mann; Mansiangi, Paul; Bernard, Kabore; Mulakub-Yazho, Guy Jerome Nkay; Famasulu, Honore Minka

    2017-09-19

    The lack of safe water and sanitation contributes to the rampancy of diarrhea in many developing countries. This study describes the design of a cluster-randomized trial in Idiofa, the Democratic Republic of the Congo, seeking evidence of the impact of improved sanitation on diarrhea for children under four. Of the 276 quartiers, 18 quartiers were randomly allocated to the intervention or control arm. Seven hundred and-twenty households were sampled and the youngest under-four child in each household was registered for this study. The primary endpoint of the study is diarrheal incidence, prevalence and duration in children under five. Material subsidies will be provided only to the households who complete pit digging plus superstructure and roof construction, regardless of their income level. This study employs a Sanitation Calendar so that the mother of each household can record the diarrheal episodes of her under-four child on a daily basis. The diary enables examination of the effect of the sanitation intervention on diarrhea duration and also resolves the limitation of the small number of clusters in the trial. In addition, the project will be monitored through the 'Sanitation Map', on which all households in the study area, including both the control and intervention arms, are registered. To avoid information bias or courtesy bias, photos will be taken of the latrine during the household visit, and a supervisor will determine well-equipped latrine uptake based on the photos. This reduces the possibility of recall bias and under- or over-estimation of diarrhea, which was the main limitation of previous studies. The study was approved by the Institutional Review Board of the School of Public Health, Kinshasa University (ESP/CE/040/15; April 13, 2015) and registered as an International Standard Randomized Controlled Trial (ISRCTN: 10,419,317) on March 13, 2015.

  8. Calcitonin gene-related peptide antagonism and cluster headache

    DEFF Research Database (Denmark)

    Ashina, Håkan; Newman, Lawrence; Ashina, Sait

    2017-01-01

    Calcitonin gene-related peptide (CGRP) is a key signaling molecule involved in migraine pathophysiology. Efficacy of CGRP monoclonal antibodies and antagonists in migraine treatment has fueled an increasing interest in the prospect of treating cluster headache (CH) with CGRP antagonism. The exact...... role of CGRP and its mechanism of action in CH have not been fully clarified. A search for original studies and randomized controlled trials (RCTs) published in English was performed in PubMed and in ClinicalTrials.gov . The search term used was "cluster headache and calcitonin gene related peptide......" and "primary headaches and calcitonin gene related peptide." Reference lists of identified articles were also searched for additional relevant papers. Human experimental studies have reported elevated plasma CGRP levels during both spontaneous and glyceryl trinitrate-induced cluster attacks. CGRP may play...

  9. A mixed methods pilot study with a cluster randomized control trial to evaluate the impact of a leadership intervention on guideline implementation in home care nursing

    Directory of Open Access Journals (Sweden)

    Tourangeau Ann

    2008-12-01

    Full Text Available Abstract Background Foot ulcers are a significant problem for people with diabetes. Comprehensive assessments of risk factors associated with diabetic foot ulcer are recommended in clinical guidelines to decrease complications such as prolonged healing, gangrene and amputations, and to promote effective management. However, the translation of clinical guidelines into nursing practice remains fragmented and inconsistent, and a recent homecare chart audit showed less than half the recommended risk factors for diabetic foot ulcers were assessed, and peripheral neuropathy (the most significant predictor of complications was not assessed at all. Strong leadership is consistently described as significant to successfully transfer guidelines into practice. Limited research exists however regarding which leadership behaviours facilitate and support implementation in nursing. The purpose of this pilot study is to evaluate the impact of a leadership intervention in community nursing on implementing recommendations from a clinical guideline on the nursing assessment and management of diabetic foot ulcers. Methods Two phase mixed methods design is proposed (ISRCTN 12345678. Phase I: Descriptive qualitative to understand barriers to implementing the guideline recommendations, and to inform the intervention. Phase II: Matched pair cluster randomized controlled trial (n = 4 centers will evaluate differences in outcomes between two implementation strategies. Primary outcome: Nursing assessments of client risk factors, a composite score of 8 items based on Diabetes/Foot Ulcer guideline recommendations. Intervention: In addition to the organization's 'usual' implementation strategy, a 12 week leadership strategy will be offered to managerial and clinical leaders consisting of: a printed materials, b one day interactive workshop to develop a leadership action plan tailored to barriers to support implementation; c three post-workshop teleconferences. Discussion This

  10. Enhancing a sustainable healthy working life: design of a clustered randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Koolhaas Wendy

    2010-08-01

    Full Text Available Abstract Background To improve a sustainable healthy working life, we have developed the intervention 'Staying healthy at work', which endeavours to enhance work participation of employees aged 45 years and older by increasing their problem-solving capacity and stimulating their awareness of their role and responsibility towards a healthy working life. This research study aims to evaluate the process and the effectiveness of the intervention compared with care as usual. Methods/design The study is a cluster-randomized controlled trial design (randomized at the supervisor level, with a 1-year follow-up. Workers aged 45 years and older have been enrolled in the study. Workers in the intervention group are receiving the intervention 'Staying healthy at work'. The main focus of the intervention is to promote a healthy working life of ageing workers by: (1 changing workers awareness and behaviour, by emphasizing their own decisive role in attaining goals; (2 improving the supervisors' ability to support workers in taking the necessary action, by means of enhancing knowledge and competence; and (3 enhancing the use of the human resource professionals and the occupational health tools available within the organization. The supervisors in the intervention group have been trained how to present themselves as a source of support for the worker. Workers in the control group are receiving care as usual; supervisors in the control group have not participated in the training. Measurements have been taken at baseline and will be followed up at 3, 6 and 12 months. The primary outcome measures are vitality, work ability and productivity. The secondary outcomes measures include fatigue, job strain, work attitude, self-efficacy and work engagement. A process evaluation will be conducted at both the supervisor and the worker levels, and satisfaction with the content of the intervention will be assessed. Discussion The intervention 'Staying healthy at work' has the

  11. A cluster randomised feasibility trial evaluating six-month nutritional interventions in the treatment of malnutrition in care home-dwelling adults: recruitment, data collection and protocol.

    Science.gov (United States)

    Stow, Ruth; Rushton, Alison; Ives, Natalie; Smith, Christina; Rick, Caroline

    2015-01-01

    Protein energy malnutrition predisposes individuals to disease, delays recovery from illness and reduces quality of life. Care home residents are especially vulnerable, with an estimated 30%-42% at risk. There is no internationally agreed protocol for the nutritional treatment of malnutrition in the care home setting. Widely used techniques include food-based intervention and/or the use of prescribed oral nutritional supplements, but a trial comparing the efficacy of interventions is necessary. In order to define outcomes and optimise the design for an adequately powered, low risk of bias cluster randomised controlled trial, a feasibility trial with 6-month intervention is being run, to assess protocol procedures, recruitment and retention rates, consent processes and resident and staff acceptability. Trial recruitment began in September 2013 and concluded in December 2013. Six privately run care homes in Solihull, England, were selected to establish feasibility within different care home types. Residents with or at risk of malnutrition with no existing dietetic intervention in place were considered for receipt of the allocated intervention. Randomisation took place at the care home level, using a computer-generated random number list to allocate each home to either a dietetic intervention arm (food-based or prescribed supplements) or the standard care arm, continued for 6 months. Dietetic intervention aimed to increase daily calorie intake by 600 kcal and protein by 20-25 g. The primary outcomes will be trial feasibility and acceptability of trial design and allocated interventions. A range of outcome assessments and data collection tools will be evaluated for feasibility, including change in nutrient intake, anthropometric parameters and patient-centric measures, such as quality of life and self-perceived appetite. The complexities inherent in care home research has resulted in the under representation of this population in research trials. The results of this

  12. Ion pairing in ionic liquids

    International Nuclear Information System (INIS)

    Kirchner, Barbara; Malberg, Friedrich; Firaha, Dzmitry S; Hollóczki, Oldamur

    2015-01-01

    In the present article we briefly review the extensive discussion in literature about the presence or absence of ion pair-like aggregates in ionic liquids. While some experimental studies point towards the presence of neutral subunits in ionic liquids, many other experiments cannot confirm or even contradict their existence. Ion pairs can be detected directly in the gas phase, but no direct method is available to observe such association behavior in the liquid, and the corresponding indirect experimental proofs are based on such assumptions as unity charges at the ions. However, we have shown by calculating ionic liquid clusters of different sizes that assuming unity charges for ILs is erroneous, because a substantial charge transfer is taking place between the ionic liquid ions that reduce their total charge. Considering these effects might establish a bridge between the contradicting experimental results on this matter. Beside these results, according to molecular dynamics simulations the lifetimes of ion–ion contacts and their joint motions are far too short to verify the existence of neutral units in these materials. (topical review)

  13. Noninvasive neuromodulation in migraine and cluster headache.

    Science.gov (United States)

    Starling, Amaal

    2018-06-01

    The purpose of this narrative review is to provide an overview of the currently available noninvasive neuromodulation devices for the treatment of migraine and cluster headache. Over the last decade, several noninvasive devices have undergone development and clinical trials to evaluate efficacy and safety. Based on this body of work, single-pulse transcranial magnetic stimulation, transcutaneous supraorbital neurostimulation, and noninvasive vagal nerve stimulation devices have been cleared by the United States Food and Drug Administration and are available for clinical use for the treatment of primary headache disorders. Overall, these novel noninvasive devices appear to be safe, well tolerated, and have demonstrated promising results in clinical trials in both migraine and cluster headache. This narrative review will provide a summary and update of the proposed mechanisms of action, evidence, safety, and future directions of various currently available modalities of noninvasive neuromodulation for the treatment of migraine and cluster headache.

  14. Enhancing Executive Functions Among Dutch Elementary School Children Using the Train Your Mind Program: Protocol for a Cluster Randomized Trial.

    Science.gov (United States)

    Bervoets, Joachim; Jonkman, Lisa M; Mulkens, Sandra; de Vries, Hein; Kok, Gerjo

    2018-06-07

    Executive functions are higher cognitive control functions, which are essential to physical and psychological well-being, academic performance, and healthy social relationships. Executive functions can be trained, albeit without broad transfer, to this date. Broad transfer entails the translation of improved cognitive functions to daily life (behaviors). The intervention Train your Mind was designed to train executive functions among elementary school children aged 9 to 11 years, and obtain broad transfer in terms of enhanced physical activity, healthy eating, and socioemotional regulation. This paper aims to describe the cluster randomized trial to test the effectiveness of the Train your Mind intervention. Train your Mind was integrated into the existing school curriculum for 8 months (25 weeks excluding holidays). The effectiveness of the intervention was tested in a cluster randomized trial comprising 13 schools, 34 groups (school classes), and 800 children, using a battery of 6 computer tasks at pre- and postmeasurement. Each of the 3 core executive functions was measured by 2 tasks (Flanker and Go/No-Go; N-Back and Running Span; Attention Switching Task and Dots/Triangles). Moreover, we administered questionnaires that measure emotion-regulation, cognitive errors, physical activity, dietary habits, and the psycho-social determinants of diet and physical activity. Body mass index was also measured. Multilevel analyses will account for clustering at the school and group levels, and randomization took place at the school level. Results are currently being analyzed. The main purpose of this study is to test Train your Mind's effectiveness in enhancing executive functions. Second, we investigate whether increased executive functions lead to improved physical activity and healthy eating. If found effective, executive function training could easily be integrated into school curricula everywhere, and as such, boost health, academic performance, and emotion

  15. Effect of workplace- versus home-based physical exercise on pain in healthcare workers: study protocol for a single blinded cluster randomized controlled trial.

    Science.gov (United States)

    Jakobsen, Markus D; Sundstrup, Emil; Brandt, Mikkel; Kristensen, Anne Zoëga; Jay, Kenneth; Stelter, Reinhard; Lavendt, Ebbe; Aagaard, Per; Andersen, Lars L

    2014-04-07

    The prevalence and consequences of musculoskeletal pain is considerable among healthcare workers, allegedly due to high physical work demands of healthcare work. Previous investigations have shown promising results of physical exercise for relieving pain among different occupational groups, but the question remains whether such physical exercise should be performed at the workplace or conducted as home-based exercise. Performing physical exercise at the workplace together with colleagues may be more motivating for some employees and thus increase adherence. On the other hand, physical exercise performed during working hours at the workplace may be costly for the employers in terms of time spend. Thus, it seems relevant to compare the efficacy of workplace- versus home-based training on musculoskeletal pain. This study is intended to investigate the effect of workplace-based versus home-based physical exercise on musculoskeletal pain among healthcare workers. This study was designed as a cluster randomized controlled trial performed at 3 hospitals in Copenhagen, Denmark. Clusters are hospital departments and hospital units. Cluster randomization was chosen to increase adherence and avoid contamination between interventions. Two hundred healthcare workers from 18 departments located at three different hospitals is allocated to 10 weeks of 1) workplace based physical exercise performed during working hours (using kettlebells, elastic bands and exercise balls) for 5 × 10 minutes per week and up to 5 group-based coaching sessions, or 2) home based physical exercise performed during leisure time (using elastic bands and body weight exercises) for 5 × 10 minutes per week. Both intervention groups will also receive ergonomic instructions on patient handling and use of lifting aides etc. Inclusion criteria are female healthcare workers working at a hospital. Average pain intensity (VAS scale 0-10) of the back, neck and shoulder (primary outcome) and physical

  16. A cluster randomised controlled trial of a nutrition education intervention in the community.

    Science.gov (United States)

    Madigan, S M; Fleming, P; Wright, M E; Stevenson, M; Macauley, D

    2014-04-01

    Patients with enteral feeding tubes are increasingly managed in their home environment and these patients require support from a range of healthcare professionals. A cluster randomised trial of an educational intervention was undertaken among General Practitioners and nurses both in the community and in nursing home caring for patients recently discharged to primary care. This was a short, duration (nutrition education programme delivered in the work place soon after the patient was discharged from hospital. The primary outcome was an improvement in knowledge immediately after the intervention and the secondary outcome was knowledge at 6 months. Those in the intervention group had improved knowledge, which was significantly greater than those in the control group (P work-based targeted nutrition education programme is effective for improving knowledge among general practitioners and nurses both in the community and in nursing homes. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

  17. Recruitment to online therapies for depression: pilot cluster randomized controlled trial.

    Science.gov (United States)

    Jones, Ray B; Goldsmith, Lesley; Hewson, Paul; Williams, Christopher J

    2013-03-05

    Raising awareness of online cognitive behavioral therapy (CBT) could benefit many people with depression, but we do not know how purchasing online advertising compares to placing free links from relevant local websites in increasing uptake. To pilot a cluster randomized controlled trial (RCT) comparing purchase of Google AdWords with placing free website links in raising awareness of online CBT resources for depression in order to better understand research design issues. We compared two online interventions with a control without intervention. The pilot RCT had 4 arms, each with 4 British postcode areas: (A) geographically targeted AdWords, (B) adverts placed on local websites by contacting website owners and requesting links be added, (C) both interventions, (D) control. Participants were directed to our research project website linking to two freely available online CBT resource sites (Moodgym and Living Life To The Full (LLTTF)) and two other depression support sites. We used data from (1) AdWords, (2) Google Analytics for our project website and for LLTTF, and (3) research project website. We compared two outcomes: (1) numbers with depression accessing the research project website, and then chose an onward link to one of the two CBT websites, and (2) numbers registering with LLTTF. We documented costs, and explored intervention and assessment methods to make general recommendations to inform researchers aiming to use similar methodologies in future studies. Trying to place local website links appeared much less cost effective than AdWords and although may prove useful for service delivery, was not worth pursuing in the context of the current study design. Our AdWords intervention was effective in recruiting people to the project website but our location targeting "leaked" and was not as geographically specific as claimed. The impact on online CBT was also diluted by offering participants other choices of destinations. Measuring the impact on LLTTF use was

  18. Effectiveness of a Peer Support Programme versus Usual Care in Disease Management of Diabetes Mellitus Type 2 regarding Improvement of Metabolic Control: A Cluster-Randomised Controlled Trial.

    Science.gov (United States)

    Johansson, Tim; Keller, Sophie; Winkler, Henrike; Ostermann, Thomas; Weitgasser, Raimund; Sönnichsen, Andreas C

    2016-01-01

    Testing the effectiveness of peer support additionally to a disease management programme (DMP) for type 2 diabetes patients. Unblinded cluster-randomised controlled trial (RCT) involving 49 general practices, province of Salzburg, Austria. All patients enrolled in the DMP were eligible, n = 337 participated (intervention: 148 in 19 clusters; control: 189 in 20 clusters). The peer support intervention ran over 24 months and consisted of peer supporter recruitment and training, and group meetings weekly for physical exercise and monthly for discussion of diabetes related topics. At two-year follow-up, adjusted analysis revealed a nonsignificant difference in HbA1c change of 0.14% (21.97 mmol/mol) in favour of the intervention (95% CI -0.08 to 0.36%, p = 0.22). Baseline values were 7.02 ± 1.25% in the intervention and 7.08 ± 1.25 in the control group. None of the secondary outcome measures showed significant differences except for improved quality of life (EQ-5D-VAS) in controls (4.3 points on a scale of 100; 95% CI 0.08 to 8.53, p = 0.046) compared to the intervention group. Our peer support intervention as an additional DMP component showed no significant effect on HbA1c and secondary outcome measures. Further RTCs with a longer follow-up are needed to reveal whether peer support will have clinically relevant effects. This trial has been registered with Current Controlled Trials Ltd. (ISRCTN10291077).

  19. Stick–slip behavior identified in helium cluster growth in the subsurface of tungsten: effects of cluster depth

    International Nuclear Information System (INIS)

    Wang, Jinlong; Niu, Liang-Liang; Shu, Xiaolin; Zhang, Ying

    2015-01-01

    We have performed a molecular dynamics study on the growth of helium (He) clusters in the subsurface of tungsten (W) (1 0 0) at 300 K, focusing on the role of cluster depth. Irregular ‘stick–slip’ behavior exhibited during the evolution of the He cluster growth is identified, which is due to the combined effects of the continuous cluster growth and the loop punching induced pressure relief. We demonstrate that the He cluster grows via trap-mutation and loop punching mechanisms. Initially, the self-interstitial atom SIA clusters are almost always attached to the He cluster; while they are instantly emitted to the surface once a critical cluster pressure is reached. The repetition of this process results in the He cluster approaching the surface via a ‘stop-and-go’ manner and the formation of surface adatom islands (surface roughening), ultimately leading to cluster bursting and He escape. We reveal that, for the Nth loop punching event, the critical size of the He cluster to trigger loop punching and the size of the emitted SIA clusters are correspondingly increased with the increasing initial cluster depth. We tentatively attribute the observed depth effects to the lower formation energies of Frenkel pairs and the greatly reduced barriers for loop punching in the stress field of the W subsurface. In addition, some intriguing features emerge, such as the morphological transformation of the He cluster from ‘platelet-like’ to spherical, to ellipsoidal with a ‘bullet-like’ tip, and finally to a ‘bottle-like’ shape after cluster rupture. (paper)

  20. Implementation of client versus care-provider strategies to improve external cephalic version rates: a cluster randomized controlled trial.

    Science.gov (United States)

    Vlemmix, Floortje; Rosman, Ageeth N; Rijnders, Marlies E; Beuckens, Antje; Opmeer, Brent C; Mol, Ben W J; Kok, Marjolein; Fleuren, Margot A H

    2015-05-01

    To determine the effectiveness of a client or care-provider strategy to improve the implementation of external cephalic version. Cluster randomized controlled trial. Twenty-five clusters; hospitals and their referring midwifery practices randomly selected in the Netherlands. Singleton breech presentation from 32 weeks of gestation onwards. We randomized clusters to a client strategy (written information leaflets and decision aid), a care-provider strategy (1-day counseling course focused on knowledge and counseling skills), a combined client and care-provider strategy and care-as-usual strategy. We performed an intention-to-treat analysis. Rate of external cephalic version in various strategies. Secondary outcomes were the percentage of women counseled and opting for a version attempt. The overall implementation rate of external cephalic version was 72% (1169 of 1613 eligible clients) with a range between clusters of 8-95%. Neither the client strategy (OR 0.8, 95% CI 0.4-1.5) nor the care-provider strategy (OR 1.2, 95% CI 0.6-2.3) showed significant improvements. Results were comparable when we limited the analysis to those women who were actually offered intervention (OR 0.6, 95% CI 0.3-1.4 and OR 2.0, 95% CI 0.7-4.5). Neither a client nor a care-provider strategy improved the external cephalic version implementation rate for breech presentation, neither with regard to the number of version attempts offered nor the number of women accepting the procedure. © 2015 Nordic Federation of Societies of Obstetrics and Gynecology.

  1. Image Registration Algorithm Based on Parallax Constraint and Clustering Analysis

    Science.gov (United States)

    Wang, Zhe; Dong, Min; Mu, Xiaomin; Wang, Song

    2018-01-01

    To resolve the problem of slow computation speed and low matching accuracy in image registration, a new image registration algorithm based on parallax constraint and clustering analysis is proposed. Firstly, Harris corner detection algorithm is used to extract the feature points of two images. Secondly, use Normalized Cross Correlation (NCC) function to perform the approximate matching of feature points, and the initial feature pair is obtained. Then, according to the parallax constraint condition, the initial feature pair is preprocessed by K-means clustering algorithm, which is used to remove the feature point pairs with obvious errors in the approximate matching process. Finally, adopt Random Sample Consensus (RANSAC) algorithm to optimize the feature points to obtain the final feature point matching result, and the fast and accurate image registration is realized. The experimental results show that the image registration algorithm proposed in this paper can improve the accuracy of the image matching while ensuring the real-time performance of the algorithm.

  2. Culturally adaptive storytelling method to improve hypertension control in Vietnam - "We talk about our hypertension": study protocol for a feasibility cluster-randomized controlled trial.

    Science.gov (United States)

    Allison, Jeroan J; Nguyen, Hoa L; Ha, Duc A; Chiriboga, Germán; Ly, Ha N; Tran, Hanh T; Phan, Ngoc T; Vu, Nguyen C; Kim, Minjin; Goldberg, Robert J

    2016-01-14

    Vietnam is experiencing an epidemiologic transition with an increased prevalence of non-communicable diseases. At present, the major risk factors for cardiovascular disease (CVD) are either on the rise or at alarming levels in Vietnam; inasmuch, the burden of CVD will continue to increase in this country unless effective prevention and control measures are put in place. A national survey in 2008 found that the prevalence of hypertension (HTN) was approximately 25 % among Vietnamese adults and it increased with advancing age. Therefore, novel, large-scale, and sustainable interventions for public health education to promote engagement in the process of detecting and treating HTN in Vietnam are urgently needed. A feasibility randomized trial will be conducted in Hung Yen province, Vietnam to evaluate the feasibility and acceptability of a novel community-based intervention using the "storytelling" method to enhance the control of HTN in adults residing in four rural communities. The intervention will center on stories about living with HTN, with patients speaking in their own words. The stories will be obtained from particularly eloquent patients, or "video stars," identified during Story Development Groups. The study will involve two phases: (i) developing a HTN intervention using the storytelling method, which is designed to empower patients to facilitate changes in their lifestyle practices, and (ii) conducting a feasibility cluster-randomized trial to investigate the feasibility, acceptability, and potential efficacy of the intervention compared with usual care in HTN control among rural residents. The trial will be conducted at four communes, and within each commune, 25 individuals 50 years or older with HTN will be enrolled in the trial resulting in a total sample size of 100 patients. This feasibility trial will provide the necessary groundwork for a subsequent large-scale, fully powered, cluster-randomized controlled trial to test the efficacy of our novel

  3. Clustering for data mining a data recovery approach

    CERN Document Server

    Mirkin, Boris

    2005-01-01

    Often considered more as an art than a science, the field of clustering has been dominated by learning through examples and by techniques chosen almost through trial-and-error. Even the most popular clustering methods--K-Means for partitioning the data set and Ward's method for hierarchical clustering--have lacked the theoretical attention that would establish a firm relationship between the two methods and relevant interpretation aids.Rather than the traditional set of ad hoc techniques, Clustering for Data Mining: A Data Recovery Approach presents a theory that not only closes gaps in K-Mean

  4. Assessing the feasibility of interrupting the transmission of soil-transmitted helminths through mass drug administration: The DeWorm3 cluster randomized trial protocol.

    Science.gov (United States)

    Ásbjörnsdóttir, Kristjana Hrönn; Ajjampur, Sitara S Rao; Anderson, Roy M; Bailey, Robin; Gardiner, Iain; Halliday, Katherine E; Ibikounle, Moudachirou; Kalua, Khumbo; Kang, Gagandeep; Littlewood, D Timothy J; Luty, Adrian J F; Means, Arianna Rubin; Oswald, William; Pullan, Rachel L; Sarkar, Rajiv; Schär, Fabian; Szpiro, Adam; Truscott, James E; Werkman, Marleen; Yard, Elodie; Walson, Judd L

    2018-01-01

    Current control strategies for soil-transmitted helminths (STH) emphasize morbidity control through mass drug administration (MDA) targeting preschool- and school-age children, women of childbearing age and adults in certain high-risk occupations such as agricultural laborers or miners. This strategy is effective at reducing morbidity in those treated but, without massive economic development, it is unlikely it will interrupt transmission. MDA will therefore need to continue indefinitely to maintain benefit. Mathematical models suggest that transmission interruption may be achievable through MDA alone, provided that all age groups are targeted with high coverage. The DeWorm3 Project will test the feasibility of interrupting STH transmission using biannual MDA targeting all age groups. Study sites (population ≥80,000) have been identified in Benin, Malawi and India. Each site will be divided into 40 clusters, to be randomized 1:1 to three years of twice-annual community-wide MDA or standard-of-care MDA, typically annual school-based deworming. Community-wide MDA will be delivered door-to-door, while standard-of-care MDA will be delivered according to national guidelines. The primary outcome is transmission interruption of the STH species present at each site, defined as weighted cluster-level prevalence ≤2% by quantitative polymerase chain reaction (qPCR), 24 months after the final round of MDA. Secondary outcomes include the endline prevalence of STH, overall and by species, and the endline prevalence of STH among children under five as an indicator of incident infections. Secondary analyses will identify cluster-level factors associated with transmission interruption. Prevalence will be assessed using qPCR of stool samples collected from a random sample of cluster residents at baseline, six months after the final round of MDA and 24 months post-MDA. A smaller number of individuals in each cluster will be followed with annual sampling to monitor trends in

  5. Strategies to enhance venous thromboprophylaxis in hospitalized medical patients (SENTRY: a pilot cluster randomized trial

    Directory of Open Access Journals (Sweden)

    Pai Menaka

    2013-01-01

    Full Text Available Abstract Background Venous thromboembolism (VTE is a common preventable cause of mortality in hospitalized medical patients. Despite rigorous randomized trials generating strong recommendations for anticoagulant use to prevent VTE, nearly 40% of medical patients receive inappropriate thromboprophylaxis. Knowledge-translation strategies are needed to bridge this gap. Methods We conducted a 16-week pilot cluster randomized controlled trial (RCT to determine the proportion of medical patients that were appropriately managed for thromboprophylaxis (according to the American College of Chest Physician guidelines within 24 hours of admission, through the use of a multicomponent knowledge-translation intervention. Our primary goal was to determine the feasibility of conducting this study on a larger scale. The intervention comprised clinician education, a paper-based VTE risk assessment algorithm, printed physicians’ orders, and audit and feedback sessions. Medical wards at six hospitals (representing clusters in Ontario, Canada were included; three were randomized to the multicomponent intervention and three to usual care (i.e., no active strategies for thromboprophylaxis in place. Blinding was not used. Results A total of 2,611 patients (1,154 in the intervention and 1,457 in the control group were eligible and included in the analysis. This multicomponent intervention did not lead to a significant difference in appropriate VTE prophylaxis rates between intervention and control hospitals (appropriate management rate odds ratio = 0.80; 95% confidence interval: 0.50, 1.28; p = 0.36; intra-class correlation coefficient: 0.022, and thus was not considered feasible. Major barriers to effective knowledge translation were poor attendance by clinical staff at education and feedback sessions, difficulty locating preprinted orders, and lack of involvement by clinical and administrative leaders. We identified several factors that may increase uptake of a VTE

  6. The CLIMATE schools combined study: a cluster randomised controlled trial of a universal Internet-based prevention program for youth substance misuse, depression and anxiety

    Science.gov (United States)

    2014-01-01

    Background Anxiety, depressive and substance use disorders account for three quarters of the disability attributed to mental disorders and frequently co-occur. While programs for the prevention and reduction of symptoms associated with (i) substance use and (ii) mental health disorders exist, research is yet to determine if a combined approach is more effective. This paper describes the study protocol of a cluster randomised controlled trial to evaluate the effectiveness of the CLIMATE Schools Combined intervention, a universal approach to preventing substance use and mental health problems among adolescents. Methods/design Participants will consist of approximately 8400 students aged 13 to 14-years-old from 84 secondary schools in New South Wales, Western Australia and Queensland, Australia. The schools will be cluster randomised to one of four groups; (i) CLIMATE Schools Combined intervention; (ii) CLIMATE Schools - Substance Use; (iii) CLIMATE Schools - Mental Health, or (iv) Control (Health and Physical Education as usual). The primary outcomes of the trial will be the uptake and harmful use of alcohol and other drugs, mental health symptomatology and anxiety, depression and substance use knowledge. Secondary outcomes include substance use related harms, self-efficacy to resist peer pressure, general disability, and truancy. The link between personality and substance use will also be examined. Discussion Compared to students who receive the universal CLIMATE Schools - Substance Use, or CLIMATE Schools - Mental Health or the Control condition (who received usual Health and Physical Education), we expect students who receive the CLIMATE Schools Combined intervention to show greater delays to the initiation of substance use, reductions in substance use and mental health symptoms, and increased substance use and mental health knowledge. Trial registration This trial is registered with the Australian and New Zealand Clinical Trials registry, ACTRN12613000723785

  7. Factors associated with non-participation and dropout among cancer patients in a cluster-randomised controlled trial.

    Science.gov (United States)

    Roick, J; Danker, H; Kersting, A; Briest, S; Dietrich, A; Dietz, A; Einenkel, J; Papsdorf, K; Lordick, F; Meixensberger, J; Mössner, J; Niederwieser, D; Prietzel, T; Schiefke, F; Stolzenburg, J-U; Wirtz, H; Singer, S

    2018-01-01

    We investigated the impact of demographic and disease related factors on non-participation and dropout in a cluster-randomised behavioural trial in cancer patients with measurements taken between hospitalisation and 6 months thereafter. The percentages of non-participation and dropout were documented at each time point. Factors considered to be potentially related with non-participation and dropout were as follows: age, sex, marital status, education, income, employment status, tumour site and stage of disease. Of 1,338 eligible patients, 24% declined participation at baseline. Non-participation was higher in older patients (Odds Ratio [OR] 2.1, CI: 0.6-0.9) and those with advanced disease (OR 2.0, CI: 0.1-1.3). Dropout by 6 months was 25%. Dropout was more frequent with increased age (OR 2.8, CI: 0.8-1.2), advanced disease (OR 3.0, CI: 1.0-1.2), being married (OR 2.4, CI 0.7-1.1) and less frequent with university education (OR 0.4, CI -1.3 to -0.8) and middle income (OR 0.4, CI -0.9 to -0.7). When planning clinical trials, it is important to be aware of patient groups at high risk of non-participation or dropout, for example older patients or those with advanced disease. Trial designs should consider their special needs to increase their rate of participation. © 2017 John Wiley & Sons Ltd.

  8. Relay entanglement and clusters of correlated spins

    Science.gov (United States)

    Doronin, S. I.; Zenchuk, A. I.

    2018-06-01

    Considering a spin-1/2 chain, we suppose that the entanglement passes from a given pair of particles to another one, thus establishing the relay transfer of entanglement along the chain. Therefore, we introduce the relay entanglement as a sum of all pairwise entanglements in a spin chain. For more detailed studying the effects of remote pairwise entanglements, we use the partial sums collecting entanglements between the spins separated by up to a certain number of nodes. The problem of entangled cluster formation is considered, and the geometric mean entanglement is introduced as a characteristic of quantum correlations in a cluster. Generally, the lifetime of a cluster decreases with an increase in its size.

  9. Electron-induced chemistry in microhydrated sulfuric acid clusters

    Directory of Open Access Journals (Sweden)

    J. Lengyel

    2017-11-01

    Full Text Available We investigate the mixed sulfuric acid–water clusters in a molecular beam experiment with electron attachment and negative ion mass spectrometry and complement the experiment by density functional theory (DFT calculations. The microhydration of (H2SO4m(H2On clusters is controlled by the expansion conditions, and the electron attachment yields the main cluster ion series (H2SO4m(H2OnHSO4− and (H2OnH2SO4−. The mass spectra provide an experimental evidence for the onset of the ionic dissociation of sulfuric acid and ion-pair (HSO4−  ⋅  ⋅  ⋅  H3O+ formation in the neutral H2SO4(H2On clusters with n ≥ 5 water molecules, in excellent agreement with the theoretical predictions. In the clusters with two sulfuric acid molecules (H2SO42(H2On this process starts as early as n ≥ 2 water molecules. The (H2SO4m(H2OnHSO4− clusters are formed after the dissociative electron attachment to the clusters containing the (HSO4−  ⋅  ⋅  ⋅  H3O+ ion-pair structure, which leads to the electron recombination with the H3O+ moiety generating H2O molecule and the H-atom dissociation from the cluster. The (H2OnH2SO4− cluster ions point to an efficient caging of the H atom by the surrounding water molecules. The electron-energy dependencies exhibit an efficient electron attachment at low electron energies below 3 eV, and no resonances above this energy, for all the measured mass peaks. This shows that in the atmospheric chemistry only the low-energy electrons can be efficiently captured by the sulfuric acid–water clusters and converted into the negative ions. Possible atmospheric consequences of the acidic dissociation in the clusters and the electron attachment to the sulfuric acid–water aerosols are discussed.

  10. Nonpharmacologic Pain Management Interventions in German Nursing Homes: A Cluster Randomized Trial.

    Science.gov (United States)

    Kalinowski, Sonja; Budnick, Andrea; Kuhnert, Ronny; Könner, Franziska; Kissel-Kröll, Angela; Kreutz, Reinhold; Dräger, Dagmar

    2015-08-01

    The reported prevalence of pain among nursing home residents (NHRs) is high. Insufficient use of analgesics, the conventional pain management strategy, is often reported. Whether and to what extent nonpharmacologic therapies (NPTs) are used to manage the pain of NHRs in Germany is largely unknown. The aim of this cluster-randomized trial was to assess the NPTs provided and to enhance the application and prescription of NPTs in NHRs on an individual level. There were six nursing homes in the intervention group and six in the control group. There were 239 NHRs, aged ≥65 years, with an average Mini-Mental State Examination score of at least 18 at baseline. Pain management interventions (cluster level) included an online course for physicians and 1-day seminar for nurses. Data on NPT applied by nurses and therapeutic NPT prescribed by physicians were obtained from residents' nursing documentation. Face-to-face interviews with NHRs assessed the NPT received. At baseline, 82.6% of NHR (mean age 83 years) were affected by pain, but less than 1 in 10 received NPT. The intervention did not result in a significant increase in the NPT applied by nurses, but did significantly increase the therapeutic NPT prescribed by physicians. Residents were active in using NPT to self-manage their pain. Given the prevalence of pain in NHRs, there is a clear need to improve pain management in this population. Extended use of NPT offers a promising approach. We recommend that nurses provide residents with education on pain-management techniques to support them in taking a proactive role in managing their pain. Copyright © 2015 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

  11. Early intervention for adolescents with Patellofemoral Pain Syndrome - a pragmatic cluster randomised controlled trial

    Science.gov (United States)

    2012-01-01

    Background Self-reported knee pain is highly prevalent among adolescents. As much as 50% of the non-specific knee pain may be attributed to Patellofemoral Pain Syndrome (PFPS). In the short term, exercise therapy appears to have a better effect than patient education consisting of written information and general advice on exercise or compared with placebo treatment. But the long-term effect of exercise therapy compared with patient education is conflicting. The purpose of this study is to examine the short- and long-term effectiveness of patient education compared with patient education and multimodal physiotherapy applied at a very early stage of the condition among adolescents. Methods/Design This study is a single blind pragmatic cluster randomised controlled trial. Four upper secondary schools have been invited to participate in the study (approximately 2500 students, aged 15-19 years). Students are asked to answer an online questionnaire regarding musculoskeletal pain. The students who report knee pain are contacted by telephone and offered a clinical examination by a rheumatologist. Subjects who fit the inclusion criteria and are diagnosed with PFPS are invited to participate in the study. A minimum of 102 students with PFPS are then cluster-randomised into two intervention groups based on which school they attend. Both intervention groups receive written information and education. In addition to patient education, one group receives multimodal physiotherapy consisting primarily of neuromuscular training of the muscles around the foot, knee and hip and home exercises. The students with PFPS fill out self-reported questionnaires at baseline, 3, 6, 12 and 24 months after inclusion in the study. The primary outcome measure is perception of recovery measured on a 7-point Likert scale ranging from "completely recovered" to "worse than ever" at 12 months. Discussion This study is designed to investigate the effectiveness of patient education compared with patient

  12. Knowledge Translation Interventions to Improve the Timing of Dialysis Initiation: Protocol for a Cluster Randomized Trial.

    Science.gov (United States)

    Chau, Elaine M T; Manns, Braden J; Garg, Amit X; Sood, Manish M; Kim, S Joseph; Naimark, David; Nesrallah, Gihad E; Soroka, Steven D; Beaulieu, Monica; Dixon, Stephanie; Alam, Ahsan; Tangri, Navdeep

    2016-01-01

    Early initiation of chronic dialysis (starting dialysis with higher vs lower kidney function) has risen rapidly in the past 2 decades in Canada and internationally, despite absence of established health benefits and higher costs. In 2014, a Canadian guideline on the timing of dialysis initiation, recommending an intent-to-defer approach, was published. The objective of this study is to evaluate the efficacy and safety of a knowledge translation intervention to promote the intent-to-defer approach in clinical practice. This study is a multicenter, 2-arm parallel, cluster randomized trial. The study involves 55 advanced chronic kidney disease clinics across Canada. Patients older than 18 years who are managed by nephrologists for more than 3 months, and initiate dialysis in the follow-up period are included in the study. Outcomes will be measured at the patient-level and enumerated within a cluster. Data on characteristics of each dialysis start will be determined by linkages with the Canadian Organ Replacement Register. Primary outcomes include the proportion of patients who start dialysis early with an estimated glomerular filtration rate greater than 10.5 mL/min/1.73 m 2 and start dialysis in hospital as inpatients or in an emergency room setting. Secondary outcomes include the rate of change in early dialysis starts; rates of hospitalizations, deaths, and cost of predialysis care (wherever available); quarterly proportion of new starts; and acceptability of the knowledge translation materials. We randomized 55 multidisciplinary chronic disease clinics (clusters) in Canada to receive either an active knowledge translation intervention or no intervention for the uptake of the guideline on the timing of dialysis initiation. The active knowledge translation intervention consists of audit and feedback as well as patient- and provider-directed educational tools delivered at a comprehensive in-person medical detailing visit. Control clinics are only exposed to guideline

  13. Hot HB Stars in Globular Clusters: Physical Parameters and Consequences for Theory. VI; The Second Parameter Pair M 3 and M 13

    Science.gov (United States)

    Moehler, S.; Landsman, W. B.; Sweigart, A. V.; Grundahl, F.

    2003-01-01

    We present the results of spectroscopic analyses of hot horizontal branch (HB) stars in M 13 and M 3, which form a famous "second parameter" pair. F rom the spectra and Stromgren photometry we derived - for the first time in M 13 - atmospheric parameters (effective temperature and surface gravity). For stars with Stromgren temperatures between 10,000 and 12,000 K we found excellent agreement between the atmospheric parameters derived from Stromgren photometry and those derived from Balmer line profile fits. However, for cooler stars there is a disagreement in the parameters derived by the two methods, for which we have no satisfactory explanation. Stars hotter than 12,000 K show evidence for helium depletion and iron enrichment, both in M 3 and M 13. Accounting for the iron enrichment substantially improves the agreement with canonical evolutionary models, although the derived gravities and masses are still somewhat too low. This remaining discrepancy may be an indication that scaled-solar metal-rich model atmospheres do not adequately represent the highly non-solar abundance ratios found in blue HB stars affected by diffusion. We discuss the effects of an enhancement in the envelope helium abundance on the atmospheric parameters of the blue HB stars, as might be caused by deep mixing on the red giant branch or primordial pollution from an earlier generation of intermediate mass asymptotic giant branch stars. Key words. Stars: atmospheres - Stars: evolution - Stars: horizontal branch - Globular clusters: individual: M 3 - Globular clusters: individual: M 13

  14. A pair natural orbital implementation of the coupled cluster model CC2 for excitation energies.

    Science.gov (United States)

    Helmich, Benjamin; Hättig, Christof

    2013-08-28

    We demonstrate how to extend the pair natural orbital (PNO) methodology for excited states, presented in a previous work for the perturbative doubles correction to configuration interaction singles (CIS(D)), to iterative coupled cluster methods such as the approximate singles and doubles model CC2. The original O(N(5)) scaling of the PNO construction is reduced by using orbital-specific virtuals (OSVs) as an intermediate step without spoiling the initial accuracy of the PNO method. Furthermore, a slower error convergence for charge-transfer states is analyzed and resolved by a numerical Laplace transformation during the PNO construction, so that an equally accurate treatment of local and charge-transfer excitations is achieved. With state-specific truncated PNO expansions, the eigenvalue problem is solved by combining the Davidson algorithm with deflation to project out roots that have already been determined and an automated refresh with a gener