Selective serotonin reuptake inhibitors and gastrointestinal bleeding: a case-control study.

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Alfonso Carvajal

Full Text Available BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs have been associated with upper gastrointestinal (GI bleeding. Given their worldwide use, even small risks account for a large number of cases. This study has been conducted with carefully collected information to further investigate the relationship between SSRIs and upper GI bleeding. METHODS: We conducted a case-control study in hospitals in Spain and in Italy. Cases were patients aged ≥18 years with a primary diagnosis of acute upper GI bleeding diagnosed by endoscopy; three controls were matched by sex, age, date of admission (within 3 months and hospital among patients who were admitted for elective surgery for non-painful disorders. Exposures to SSRIs, other antidepressants and other drugs were defined as any use of these drugs in the 7 days before the day on which upper gastrointestinal bleeding started (index day. RESULTS: 581 cases of upper GI bleeding and 1358 controls were considered eligible for the study; no differences in age or sex distribution were observed between cases and controls after matching. Overall, 4.0% of the cases and 3.3% of controls used an SSRI antidepressant in the week before the index day. No significant risk of upper GI bleeding was encountered for SSRI antidepressants (adjusted odds ratio, 1.06, 95% CI, 0.57-1.96 or for whichever other grouping of antidepressants. CONCLUSIONS: The results of this case-control study showed no significant increase in upper GI bleeding with SSRIs and provide good evidence that the magnitude of any increase in risk is not greater than 2.

Field-based random sampling without a sampling frame: control selection for a case-control study in rural Africa.

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Crampin, A C; Mwinuka, V; Malema, S S; Glynn, J R; Fine, P E

2001-01-01

Selection bias, particularly of controls, is common in case-control studies and may materially affect the results. Methods of control selection should be tailored both for the risk factors and disease under investigation and for the population being studied. We present here a control selection method devised for a case-control study of tuberculosis in rural Africa (Karonga, northern Malawi) that selects an age/sex frequency-matched random sample of the population, with a geographical distribution in proportion to the population density. We also present an audit of the selection process, and discuss the potential of this method in other settings.

Outbreak of Salmonella Enteritidis phage type 13a: case-control investigation in Hertsmere, United Kingdom.

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Morgan, O; Milne, L; Kumar, S; Murray, D; Man, W; Georgiou, M; Verlander, N Q; de Pinna, E; McEvoy, M

2007-07-01

Cases of illness were reported to Hertsmere Borough Council among attendees of a children's charity event in June 2006. Initial laboratory investigation identified Salmonella Enteritidis PT13a as a possible cause of the outbreak. We carried out an unmatched case-control investigation. The population at risk included all individuals who attended the event. Self-completion questionnaires were sent to 53 presumptive cases and 212 randomly selected potential controls. Information was available for 49 cases and 128 controls (overall response rate=75%). We calculated odds ratios from single and multivariable analysis and tested for all two-way interactions. Risk factors for diarrhoea were eating egg mayonnaise bagels (OR=34.1, 95%CI 10.5 - 111.3) and drinking apple juice (OR=16.1, 95% CI 3.5 - 74.2). There was weak statistical evidence to suggest that the risk of diarrhoea after eating egg mayonnaise bagels was greater in the afternoon. No food samples were available to confirm which food item might have caused this outbreak. Eggs from Spain were used by the caterer. The ecology of salmonella, experience from previous outbreaks and epidemiological findings from this case-control investigation suggest that the most likely cause of the outbreak was contaminated eggs.

Case-control study of mesothelioma in the shipyard industry

International Nuclear Information System (INIS)

Correa-Villasenor, A.

1987-01-01

A nested case-control study was undertaken to investigate the relationship between occupational exposures to asbestos and low-level gamma radiation and mesothelioma. One hundred nineteen cases and four hundred fifty-two latency-matched controls were selected. Analyses were conducted using the conditional maximum likelihood estimate of the odds ratio and conditional logistic regression for matched sets. The results from the analyses revealed a relationship between asbestos exposure and mesothelioma; the strength of this relationship increased with the intensity and duration of the asbestos exposure. Exposure to low-level gamma radiation was also associated with an increased risk of mesothelioma. There was no interaction between asbestos and radiation. Shipyard employment in non-asbestos jobs and male gender were also found to be associated with mesothelioma

Effect of alpha amylase on early childhood caries: a matched case-control study

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Mojarad, Farzad; Department of Pediatric Dentistry, School of Dentistry, Hamadan University of Medical Sciences, Hamadan; Fazlollahifar, Samira; Department of Pediatric Dentistry, School of Dentistry, Hamadan University of Medical Sciences, Hamadan; Poorolajal, Jalal; Research Center for Health Sciences, Department of Epidemiology & Biostatistics, School of Public Health, Hamadan University of Medical Sciences, Hamadan; Hajilooi, Mehrdad; Department of Pathology, School of Dentistry, Hamadan University of Medical Sciences, Hamadan

2013-01-01

Objectives: There are a few studies addressing the relationship between salivary alpha-amylase and dental caries. This study was implemented in order to investigate the effect of salivary alpha-amylase level on early childhood caries (ECC).Materials and Methods: In this matched case-control study, which was carried out from November 2011 to March 2012 in Hamadan City, the west of Iran, mean levels of salivary alpha-amylase of 84 ECC-active cases were compared to that of 84 ECC-free controls u...

External radiotherapy prior to thyroid cancer: A case-control study

International Nuclear Information System (INIS)

Hallquist, A.; Loefroth, P.O.; Hardell, L.

1993-01-01

The aim of this investigation was to study previous radiotherapy of malignant diseases as a risk factor for thyroid cancer. By using the Swedish Cancer Registry all cases of thyroid cancer with another malignant disease at least one year previously and living within the catchment area of the hospital were traced. During 1959-1989 a total of 1056 cases of thyroid cancer were identified. Of these, 37 had had another previous malignant disease and they constituted the cases in this study. As controls four persons with at least two malignant diseases, thyroid cancer excluded, were selected for each case from the same cancer registry. Ten (27.0%) of the 37 patients with thyroid cancer as a second tumor had earlier been irradiated with the treatment dose including the thyroid gland as compared with 34 (24.5%) of the 139 control patients. Eight of the ten cases with previous irradiation of the thyroid gland had papillary cancer. The median latency was 13 years. The estimated radiation dose in the thyroid varied between 3 and 40 Gy. External radiotherapy gave a crude odds ratio of 1.1 with 95% confidence interval = 0.5-2.8 for thyroid cancer. The weighted odds ratio was calculated to 2.3 with confidence interval = 0.5-8.9. This case-control study gave a nonsignificantly increased odds ratio for thyroid cancer in patients with external radiotherapy including the thyroid gland. 26 refs., 4 tabs

Case Studies in Modelling, Control in Food Processes.

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Glassey, J; Barone, A; Montague, G A; Sabou, V

This chapter discusses the importance of modelling and control in increasing food process efficiency and ensuring product quality. Various approaches to both modelling and control in food processing are set in the context of the specific challenges in this industrial sector and latest developments in each area are discussed. Three industrial case studies are used to demonstrate the benefits of advanced measurement, modelling and control in food processes. The first case study illustrates the use of knowledge elicitation from expert operators in the process for the manufacture of potato chips (French fries) and the consequent improvements in process control to increase the consistency of the resulting product. The second case study highlights the economic benefits of tighter control of an important process parameter, moisture content, in potato crisp (chips) manufacture. The final case study describes the use of NIR spectroscopy in ensuring effective mixing of dry multicomponent mixtures and pastes. Practical implementation tips and infrastructure requirements are also discussed.

Exposure to pistachio pesticides and stillbirth: a case-control study.

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Razi, Saeid; Rezaeian, Mohsen; Dehkordi, Fatemeh Ghani; Manshoori, Azita; Goujani, Reza; Vazirinejad, Reza

2016-01-01

Stillbirth is an undesirable outcome of pregnancy. In light of the increasing use of pesticides and growing concerns about the possible health effects of agricultural pesticides, we investigated the effect of exposure to pistachio pesticides on stillbirth in pregnant mothers. This case-control study was conducted in Rafsanjan, Iran from 2011 to 2012. A total of 125 females who had a recent stillbirth were included as the case group, and 250 controls were selected from females who had a recent live birth. For each case, two controls with the nearest propensity score to the case were selected. Data were collected using a protocol developed by the researcher that involved interviewing respondents and reviewing their medical records. Conditional multivariate and univariate logistic regression analysis were performed and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. The ORs of stillbirth in mothers living in pistachio gardens and those who were exposed to sprayed pesticides, in comparison to the controls, were 14.1 (95% CI, 3.3 to 63.4) and 5.0 (95% CI, 1.2 to 28.6), respectively. No significant differences were found in stillbirth rates according to the distance between the mother's residence and a pistachio garden or involvement in agricultural activities. The results of our study showed that exposure to pistachio pesticides during pregnancy may increase the likelihood of stillbirth in mothers.

Psychosocial and Psychiatric Factors Associated with Adolescent Suicide: A Case-Control Psychological Autopsy Study

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Portzky, Gwendolyn; Audenaert, Kurt; van Heeringen, Kees

2009-01-01

This study aimed at the investigation of psychosocial and psychiatric risk factors of adolescent suicide by means of a case-control psychological autopsy study. Relatives and other informants of 19 suicide victims and 19 matched psychiatric controls were interviewed by means of a semi-structured interview schedule. Psychiatric controls included…

Alcohol and Difficulty Conceiving in the SUN Cohort: A Nested Case-Control Study

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Cristina Lopez-del Burgo; Alfredo Gea; Jokin de Irala; Miguel A. Martínez-González; Jorge E. Chavarro; Estefania Toledo

2015-01-01

The role of alcohol on fertility remains unclear. We aimed to investigate the association between alcohol and specific alcoholic beverages consumption and the risk of difficulty getting pregnant. We used a case-control study nested within the Seguimiento Universidad de Navarra (SUN) cohort, a prospective, dynamic and multipurpose cohort of 21,705 Spanish university graduates, followed biennially with mailed questionnaires. We identified 686 case-control pairs, matched for age and time in the ...

Qat use and esophageal cancer in Ethiopia: A pilot case-control study.

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Maria E Leon

and religion differing between cases and controls. A large case-control study with enrolment of EC cases and carefully matched controls at health facilities from high-risk areas in the countryside, where the majority of cases occur, is needed to further investigate the association between qat use and EC.

Exposure to pistachio pesticides and stillbirth: a case-control study

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Saeid Razi

2016-04-01

Full Text Available OBJECTIVES Stillbirth is an undesirable outcome of pregnancy. In light of the increasing use of pesticides and growing concerns about the possible health effects of agricultural pesticides, we investigated the effect of exposure to pistachio pesticides on stillbirth in pregnant mothers. METHODS This case-control study was conducted in Rafsanjan, Iran from 2011 to 2012. A total of 125 females who had a recent stillbirth were included as the case group, and 250 controls were selected from females who had a recent live birth. For each case, two controls with the nearest propensity score to the case were selected. Data were collected using a protocol developed by the researcher that involved interviewing respondents and reviewing their medical records. Conditional multivariate and univariate logistic regression analysis were performed and odds ratios (ORs and 95% confidence intervals (CIs were calculated. RESULTS The ORs of stillbirth in mothers living in pistachio gardens and those who were exposed to sprayed pesticides, in comparison to the controls, were 14.1 (95% CI, 3.3 to 63.4 and 5.0 (95% CI, 1.2 to 28.6, respectively. No significant differences were found in stillbirth rates according to the distance between the mother’s residence and a pistachio garden or involvement in agricultural activities. CONCLUSIONS The results of our study showed that exposure to pistachio pesticides during pregnancy may increase the likelihood of stillbirth in mothers.

Leptospira Exposure and Gardeners: A Case-Control Seroprevalence Study

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Alvarado-Esquivel, Cosme; Hernandez-Tinoco, Jesus; Sanchez-Anguiano, Luis Francisco; Ramos-Nevarez, Agar; Cerrillo-Soto, Sandra Margarita; Guido-Arreola, Carlos Alberto

2016-01-01

Background Leptospira can be found in soil. However, it is unclear whether occupational exposure to soil may represent a risk for Leptospira infection in humans. Therefore, we sought to determine the association of Leptospira IgG seroprevalence with the occupation of gardener, and to determine the epidemiological characteristics of gardeners associated with Leptospira exposure. Methods We performed a case-control study in 168 gardeners and 168 age- and gender-matched control subjects without gardening occupation in Durango City, Mexico. The seroprevalence of anti-Leptospira IgG antibodies in cases and controls was determined using an enzyme immunoassay. Bivariate and multivariate analyses were used to assess the association of Leptospira exposure and the characteristics of the gardeners. Results Anti-Leptospira IgG antibodies were found in 10 (6%) of 168 gardeners and in 15 (8.9%) of 168 control subjects (odds ratio (OR): 0.64; 95% confidence interval (CI): 0.28 - 1.48; P = 0.40). Multivariate analysis showed that Leptospira seropositivity was positively associated with female gender (OR: 5.82; 95% CI: 1.11 - 30.46; P = 0.03), and negatively associated with eating while working (OR: 0.21; 95% CI: 0.05 - 0.87; P = 0.03). In addition, multivariate analysis showed that high anti-Leptospira levels were associated with consumption of boar meat (OR: 28.00; 95% CI: 1.20 - 648.80; P = 0.03). Conclusions This is the first case-control study of Leptospira exposure in gardeners. Results do not support an association of Leptospira exposure with the occupation of gardener. However, further studies to confirm the lack of this association are needed. The potential role of consumption of boar meat in Leptospira infection deserves further investigation. PMID:26668679

An epidemiological investigation of the early phase of the porcine epidemic diarrhea (PED) outbreak in Canadian swine herds in 2014: A case-control study.

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Perri, Amanda M; Poljak, Zvonimir; Dewey, Cate; Harding, John C S; O'Sullivan, Terri L

2018-02-01

The first case of porcine epidemic diarrhea (PED) in Canada was diagnosed in January 2014 in Ontario, approximately 9 months after PED emerged in the United States. An early investigation of the Canadian outbreak suspected that the probable source of the virus was contaminated feed. The objective of this study was to evaluate the role of feed and other possible factors in the early phase of the PED outbreak in Canadian swine herds. The study period of interest for this case-control study was January 22nd to March 1st, 2014. A case herd was defined as a swine herd with a confirmed positive laboratory diagnostic test (RT-PCR) results for PED virus, along with pigs exhibiting typical clinical signs at the herd level during the study period. A questionnaire was administered to participating producers from the 22 Canadian swine herds enrolled (n = 9 case and n = 13 control herds). Case herd producers were asked to provide information from the initial day of onset of clinical signs and 30 days prior to that day. Control herds were matched to a case herd on the basis of province, herd type and approximate size. The period of interest for a control herd was matched to the initial day of clinical signs of PED for the case herd, along with the 30 days prior to this day. The questionnaire questions focused on herd demographics, biosecurity protocols, live animal movements onto and off sites, deadstock movements, feed and people movements for both the case and control herds. The questionnaire for control herds were based on their matched case's period of interest, and together with case herds formed a matched stratum. Multivariable exact conditional logistic regression and mixed multivariable logistic regression models, with the matched stratum as a random effect, were used to assess the association between various risk factors and the odds of PED introduction into a herd. After adjusting for biosecurity practices, the odds of a PED occurrence was 38.1 (95% CI: 2

Homocyst(e)ine and cardiovascular disease: a systematic review of the evidence with special emphasis on case-control studies and nested case-control studies.

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Ford, Earl S; Smith, S Jay; Stroup, Donna F; Steinberg, Karen K; Mueller, Patricia W; Thacker, Stephen B

2002-02-01

Elevated concentrations of homocyst(e)ine are thought to increase the risk of vascular diseases including coronary heart disease and cerebrovascular disease. We searched MEDLINE (1966-1999), EMBASE (1974-1999), SciSearch (1974- 1999), and Dissertation Abstracts (1999) for articles and theses about homocyst(e)ine concentration and coronary heart disease and cerebrovascular disease. We included 57 publications (3 cohort studies, 12 nested case-control studies, 42 case-control studies) that reported results on 5518 people with coronary heart disease (11,068 control subjects) and 1817 people with cerebrovascular disease (4787 control subjects) in our analysis. For coronary heart disease, the summary odds ratios (OR) for a 5-micromol/l increase in homocyst(e)ine concentration were 1.06 (95% CI : 0.99-1.13) for 2 publications of cohort studies, 1.23 (95% CI : 1.07-1.41) for 10 publications of nested case-control studies, and 1.70 (95% CI : 1.50-1.93) for 26 publications of case-control studies. For cerebrovascular disease, the summary OR for a 5-micromol/l increase in homocyst(e)ine concentration were 1.10 (95% CI : 0.94-1.28) for 2 publications of cohort studies, 1.58 (95% CI : 1.35-1.85) for 5 publications of nested case-control studies, and 2.16 (95% CI : 1.65-2.82) for 17 publications of case-control studies. Prospective studies offer weaker support than case-control studies for an association between homocyst(e)ine concentration and cardiovascular disease. Although other lines of evidence support a role for homocyst(e)ine in the pathogenesis of cardiovascular disease, more information from prospective epidemiological studies or clinical trials is needed to clarify this role.

Association between smoking habits and acne vulgaris. A case-control study

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Alice Mannocci

2012-09-01

Full Text Available

Background: acne vulgaris, is one of the most common skin disorder. Previous studies about the role of smoke in the pathogenesis of acne reported contradictory results. The aim of this study was to conduct a case-control study investigating the relationship between tobacco smoking and acne.

Methods: a case-control study was performed during the period September 2009 - February 2010. A questionnaire was administrated to each participant, to assess the association acne - smoke. Cases were outpatients of the Dermatologic Ambulatory of the “Fiorini” Hospital, Sapienza University of Rome (Italy. Controls were age and gender-matched to the cases. The ratio cases-controls was 1:2. A univariate and a multiple logistic regression analysis were conducted; Odds Ratio (OR and the relative 95% confidence interval (95%CI were assessed. The statistical significance was set at p < 0.05.

Results: crude OR for the association acne - smoke was 7.26 (IC=2.27-23.18; adjusted OR for sex and age was 5.47 (IC=1.67-17.97. Of 93 cases, 6 had a severe grade of acne (6.5%, 19 had an intermediate grade of acne (20.4%, and 68 had a mild grade of acne (73.1%. No one of the smokers had a severe grade of acne, one had an intermediate grade of acne and 11 had mild acne; these differences are not statistically significant.

Conclusions: the association between acne and smoke shows an increased risk (OR=7.26 with a statistically significant CI. Moreover, people ≥ 18 years of age have twice the risk compared to persons < 18 years of age (OR=2.31.

Pesticide Exposure and Head and Neck Cancers: A Case-Control Study in an Agricultural Region

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Maryam Amizadeh

2017-09-01

Full Text Available Introduction: Causes of head and neck cancers (HNCs are multifactorial, and few studies have investigated the association between chemical exposure and HNCs. The objective of this study was to investigate associations between HNCs, agricultural occupations, and pesticide exposure. The potential for the accumulation of pesticides in the adipose tissue of patients was also investigated.   Materials and Methods: A structured questionnaire was used to collect information on demographics, occupation, and exposure to pesticides in a hospital-based case-control study. Pesticide residue in the adipose tissue of the neck in both cases and controls was also monitored via gas chromatography–mass spectroscopy.   Results: Thirty-one HNC cases were included in this study as well as 32 gender-, age-, and smoking-matched controls. An agricultural occupation was associated with HNC (odds ratio [OR], 3.26; 95% confidence interval [CI], 1.13–9.43 after controlling for age, sex, and smoking. Pesticide exposure was associated with total HNC cases (OR, 7.45; 95% CI, 1.78–3.07 and larynx cancer (OR, 9.33; 95% CI, 1.65–52.68. A dose-response pattern was observed for HNC cases (P=0.06 and larynx cancer (P=0.01. In tracing the pesticide residue, five chlorinated pesticides, namely dichlorodiphenyltrichloroethane (DDT, dichlorodipheny-ldichloroethane (DDD, dichlorodiphenyldichloroethylene (DDE, dieldrin, and lindane, were identified in the adipose tissue. Chlorinated pesticide detection was significantly associated with HNC (OR, 3.91; 95% CI 0.9–0.16.9.   Conclusion: HNCs were found to be associated with pesticide exposure after controlling for confounders. A high education level was identified as a modifying factor decreasing the risk of HNCs. Further studies with larger number of subjects are recommended to assess these relationships in greater detail.

A forensic perspective of the AFL investigation into peptides: an antidoping investigation case study.

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Harcourt, Peter Rex; Marclay, Francois; Clothier, Brett

2014-05-01

The World Anti-Doping Agency (WADA) is introducing enhancements to doping investigations in its 2015 Code, which include improved sharing of information between antidoping organisations (including sporting bodies) and enhanced accountability of athlete support staff. These additions will improve the control of links between sports doping and organised crime. In February 2013 the Australian Crime Commission released a report that linked several professional sporting codes, professional athletes with links to organised crime, performance enhancing drugs and illicit substances. Following this report the Australian Football League (AFL) partnered the Australian national antidoping organisation to investigate peptide use in Australian football. This review compared the model proposed by Marclay, a hypothetical model for anti-doping investigations that proposed a forensic intelligence and analysis approach, to use the forensic capabilities of the AFL investigation to test the model's relevance to an actual case. The investigation uncovered the use of peptides used to enhance athlete performance. The AFL investigation found a high risk of doping where athlete support staff existed in teams with weak corporate governance controls. A further finding included the need for the investigation to provide a timely response in professional team sports that were sensitive to the competition timing. In the case of the AFL the team was sanctioned prior to the finals as an interim outcome for allowing the risk of use of performance-enhancing substances. Doping violation charges are still being considered. Antidoping strategies should include the investigation of corporate officers in team doping circumstances, the mandatory recording of all athlete substance use during competition and training phases, the wider sharing of forensic intelligence with non-sporting bodies particularly law enforcement and collaboration between antidoping and sporting organisations in doping investigations

Risk factors for cataract: A case control study

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Ughade Suresh

1998-01-01

Full Text Available The present study was designed as a hospital-based, group-matched, case-control investigation into the risk factors associated with age-related cataract in central India. The study included 262 cases of age-related cataract and an equal number of controls. A total of 21 risk factors were evaluated: namely, low socioeconomic status (SES, illiteracy, marital status, history of diarrhoea, history of diabetes, glaucoma, use of cholinesterase inhibitors, steroids, spironolactone, nifedipine, analgesics, myopia early in life, renal failure, heavy smoking, heavy alcohol consumption, hypertension, low body mass index (BMI, use of cheaper cooking fuel, working in direct sunlight, family history of cataract, and occupational exposure. In univariate analysis, except marital status, low BMI, renal failure, use of steroids, spironolactone, analgesics, and occupational exposure, all 14 other risk factors were found significantly associated with age-related cataract. Unconditional multiple logistic regression analysis confirmed the significance of low SES, illiteracy, history of diarrhoea, diabetes, glaucoma, myopia, smoking, hypertension and cheap cooking fuel. The etiological role of these risk factors in the outcome of cataract is confirmed by the estimates of attributable risk proportion. The estimates of population attributable risk proportion for these factors highlight the impact of elimination of these risk factors on the reduction of cataract in this population.

Health issues in the Arab American community. Male infertility in Lebanon: a case-controlled study.

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Kobeissi, Loulou; Inhorn, Marcia C

2007-01-01

The impact of risk factors, such as consanguinity and familial clustering, reproductive infections, traumas, and diseases, lifestyle factors and occupational and war exposures on male infertility, was investigated in a case-controlled study conducted in Lebanon. One-hundred-twenty males and 100 controls of Lebanese, Syrian or Lebanese-Palestinian descents were selected from two in-vitro fertilization (IVF) clinics located in Beirut, Lebanon. All cases suffered from impaired sperm count and function, according to World Health Organization guidelines for semen analysis. Controls were the fertile husbands of infertile women. Data were collected using a semi-structured interview, laboratory blood testing and the results of the most recent semen analysis. Univariate, bivariate and multivariate logistic regression analyses were used for data analysis, along with checks for effect modification and control of confounders. Consanguinity and the familial clustering of male infertility cases, as well as reproductive illnesses and war exposures were independently significant risk factors for male infertility. The odds of having infertility problems in the immediate family were 2.6 times higher in cases than controls. The odds of reproductive illness were 2 times higher in cases than controls. The odds of war exposures were 1.57 times higher in cases than controls. Occupational exposures, such as smoking and caffeine intake, were not shown to be important risk factors. This case-controlled study highlights the importance of investigating the etiology of male infertility in Middle Eastern communities. It suggests the need to expand research on male reproductive health in the Middle East in order to improve the prevention and management of male infertility and other male reproductive health problems.

Matched case-control studies: a review of reported statistical methodology

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Niven DJ

2012-04-01

Full Text Available Daniel J Niven1, Luc R Berthiaume2, Gordon H Fick1, Kevin B Laupland11Department of Critical Care Medicine, Peter Lougheed Centre, Calgary, 2Department of Community Health Sciences, University of Calgary, Calgary, Alberta, CanadaBackground: Case-control studies are a common and efficient means of studying rare diseases or illnesses with long latency periods. Matching of cases and controls is frequently employed to control the effects of known potential confounding variables. The analysis of matched data requires specific statistical methods.Methods: The objective of this study was to determine the proportion of published, peer reviewed matched case-control studies that used statistical methods appropriate for matched data. Using a comprehensive set of search criteria we identified 37 matched case-control studies for detailed analysis.Results: Among these 37 articles, only 16 studies were analyzed with proper statistical techniques (43%. Studies that were properly analyzed were more likely to have included case patients with cancer and cardiovascular disease compared to those that did not use proper statistics (10/16 or 63%, versus 5/21 or 24%, P = 0.02. They were also more likely to have matched multiple controls for each case (14/16 or 88%, versus 13/21 or 62%, P = 0.08. In addition, studies with properly analyzed data were more likely to have been published in a journal with an impact factor listed in the top 100 according to the Journal Citation Reports index (12/16 or 69%, versus 1/21 or 5%, P ≤ 0.0001.Conclusion: The findings of this study raise concern that the majority of matched case-control studies report results that are derived from improper statistical analyses. This may lead to errors in estimating the relationship between a disease and exposure, as well as the incorrect adaptation of emerging medical literature.Keywords: case-control, matched, dependent data, statistics

Risk factors associated with hantavirosis fatality: a regional analysis from a case-control study in Brazil

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Maria Cristina Antunes Willemann

2014-01-01

Full Text Available Introduction: In Brazil, hantavirus cardiopulmonary syndrome (HCPS has a high lethality rate that varies by region. This study aimed to identify the risk factors associated with fatal hantavirosis. Methods: This study was a case-control study that included all laboratory confirmed cases of hantavirosis. The cases were stratified by the different Brazilian regions using data from the Notifiable Diseases Information System. “Cases” were patients who progressed to death, whereas “controls” were patients who were cured. The odds ratio (OR and the adjusted OR were calculated. Results: Overall, 158 cases and 281 controls were included in this study. In the Midwest region, the cases were 60% less likely to present with flank pain, and the time between the beginning of symptoms and death was shorter than the time between the beginning of symptoms and a cure. In the Southeast region, the cases were 60% less likely to present with thrombocytopenia or reside in rural areas compared to those who progressed to a cure. Additionally, the cases sought medical assistance, notification and investigation more quickly than the controls. In the Southern region, the cases that died were 70% less likely to be male compared to the controls. Conclusions: HCPS manifests with nonspecific symptoms, and there are few published studies related to the condition, so determining a patient's therapeutic strategy is difficult. This study presents findings from different Brazilian regions and highlights the need for further investigations to improve comprehension about regional risk factors associated with hantavirosis and to reduce morbimortality.

Population versus hospital controls for case-control studies on cancers in Chinese hospitals.

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Li, Lin; Zhang, Min; Holman, D'Arcy

2011-12-15

Correct control selection is crucial to the internal validity of case-control studies. Little information exists on differences between population and hospital controls in case-control studies on cancers in Chinese hospital setting. We conducted three parallel case-control studies on leukemia, breast and colorectal cancers in China between 2009 and 2010, using population and hospital controls to separately match 540 incident cases by age, gender and residency at a 1:1 ratio. Demographic and lifestyle factors were measured using a validated questionnaire in face-to-face interview. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained using conditional logistic regression analyses. The two control groups had closely similar exposure distributions of 15 out of 16 factors, with the only exception being that hospital controls were less likely to have a BMI ≥ 25 (OR = 0.71, 95% CI: 0.54, 0.93). For exposure of green tea drinking, the adjusted ORs (95% CIs) comparing green tealeaves intake ≥ 1000 grams annually with non-drinkers were 0.51 (0.31, 0.83) and 0.21 (0.27, 0.74) for three cancers combined, 0.06 (0.01, 0.61) and 0.07 (0.01, 0.47) for breast cancer, 0.52 (0.29, 0.94) and 0.45 (0.25, 0.82) for colorectal cancer, 0.65 (0.08, 5.63) and 0.57 (0.07, 4.79) for leukemia using hospital and population controls respectively. The study found that hospital controls were comparable with population controls for most demographic characteristics and lifestyle factors measured, but there was a slight difference between the two control groups. Hospital outpatients provide a satisfactory control group in hospital-based case-control study in the Chinese hospital setting.

Population versus hospital controls for case-control studies on cancers in Chinese hospitals

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Li Lin

2011-12-01

Full Text Available Abstract Background Correct control selection is crucial to the internal validity of case-control studies. Little information exists on differences between population and hospital controls in case-control studies on cancers in Chinese hospital setting. Methods We conducted three parallel case-control studies on leukemia, breast and colorectal cancers in China between 2009 and 2010, using population and hospital controls to separately match 540 incident cases by age, gender and residency at a 1:1 ratio. Demographic and lifestyle factors were measured using a validated questionnaire in face-to-face interview. Odds ratios (ORs and 95% confidence intervals (CIs were obtained using conditional logistic regression analyses. Results The two control groups had closely similar exposure distributions of 15 out of 16 factors, with the only exception being that hospital controls were less likely to have a BMI ≥ 25 (OR = 0.71, 95% CI: 0.54, 0.93. For exposure of green tea drinking, the adjusted ORs (95% CIs comparing green tealeaves intake ≥ 1000 grams annually with non-drinkers were 0.51 (0.31, 0.83 and 0.21 (0.27, 0.74 for three cancers combined, 0.06 (0.01, 0.61 and 0.07 (0.01, 0.47 for breast cancer, 0.52 (0.29, 0.94 and 0.45 (0.25, 0.82 for colorectal cancer, 0.65 (0.08, 5.63 and 0.57 (0.07, 4.79 for leukemia using hospital and population controls respectively. Conclusions The study found that hospital controls were comparable with population controls for most demographic characteristics and lifestyle factors measured, but there was a slight difference between the two control groups. Hospital outpatients provide a satisfactory control group in hospital-based case-control study in the Chinese hospital setting.

Study Design for a Case Control Investigation of Cellular Telephones and Other Risk Factors for Brain Tumors in Adults

International Nuclear Information System (INIS)

Inskip, P.D.; Hatch, E.E.; Stewart, P.A.; Heineman, E.F.; Ziegler, R.G.; Dosemeci, M.; Parry, D.; Rothman, N.; Boice, J.D. Jr.; Wilcosky, T.C.; Watson, D.J.; Shapiro, W.R.; Selker, R.G.; Fine, H.A.; Black, P. McL.; Loeffler, J.S.; Linet, M.S.

1999-01-01

The aetiology of brain tumours is poorly understood. Due, in part, to public concern about a postulated relationship between the use of cellular telephones or other increasingly prevalent environmental exposures and the incidence of brain cancer in adults, the National Cancer Institute is collaborating with three US hospitals in a comprehensive case control study of malignant and benign brain tumours. Factors under consideration include use of cellular phones and other wireless communication devices, workplace exposures to chemical agents and electromagnetic fields, dietary factors, family history of tumours, genetic determinants of susceptibility, home appliance use, reproductive history and hormonal exposures, viruses, medical and dental exposure to ionising radiation, and other aspects of medical history. Approximately 800 newly diagnosed brain tumour cases and 800 controls were enrolled at hospitals in Boston, Phoenix and Pittsburgh from 1994 to 1998. Cases include all adults (age ≥ 18 y) newly diagnosed with a histologically confirmed intracranial glioma, histologically confirmed intracranial meningioma or acoustic neuroma. Controls are patients admitted to the same hospitals as the cases, and treated for any of a variety of non-malignant conditions. Key features of the study include its large size, the emphasis on rapid ascertainment of incident cases and interview of study subjects rather than surrogate respondents, the use of detailed, job-specific questions developed by industrial hygienists to ascertain occupational exposures, and the storage of blood samples for future evaluation of inherited susceptibility, biomarkers of exposure and gene environment interactions. (author)

Assessment of global phase uncertainty in case-control studies

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van Houwelingen Hans C

2009-09-01

Full Text Available Abstract Background In haplotype-based candidate gene studies a problem is that the genotype data are unphased, which results in haplotype ambiguity. The measure 1 quantifies haplotype predictability from genotype data. It is computed for each individual haplotype, and for a measure of global relative efficiency a minimum value is suggested. Alternatively, we developed methods directly based on the information content of haplotype frequency estimates to obtain global relative efficiency measures: and based on A- and D-optimality, respectively. All three methods are designed for single populations; they can be applied in cases only, controls only or the whole data. Therefore they are not necessarily optimal for haplotype testing in case-control studies. Results A new global relative efficiency measure was derived to maximize power of a simple test statistic that compares haplotype frequencies in cases and controls. Application to real data showed that our proposed method gave a clear and summarizing measure for the case-control study conducted. Additionally this measure might be used for selection of individuals, who have the highest potential for improving power by resolving phase ambiguity. Conclusion Instead of using relative efficiency measure for cases only, controls only or their combined data, we link uncertainty measure to case-control studies directly. Hence, our global efficiency measure might be useful to assess whether data are informative or have enough power for estimation of a specific haplotype risk.

Association Between Zolpidem Use and Glaucoma Risk: A Taiwanese Population-Based Case-Control Study

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Ho, Yi-Hao; Chang, Yue-Cune; Huang, Wei-Cheng; Chen, Hsin-Yi; Lin, Che-Chen; Sung, Fung-Chang

2015-01-01

Background To date, the relationship between zolpidem use and subsequent risk of glaucoma in a Taiwanese population has not been assessed. Methods We used data from the National Health Insurance system to investigate whether zolpidem use was related to glaucoma risk. A 1:4 matched case-control study was conducted. The cases were patients newly diagnosed with glaucoma from 2001 to 2010. The controls were randomly selected non-glaucoma subjects matched by sex and age (?5 years). Zolpidem exposu...

Waterparks are high risk for cryptosporidiosis: A case-control study in Victoria, 2015.

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de Gooyer, Tanyth E; Gregory, Joy; Easton, Marion; Stephens, Nicola; Fearnley, Emily; Kirk, Martyn

2017-06-30

An increase in notifications of cryptosporidiosis was observed in Victoria between March and April 2015. Cases mostly resided in one metropolitan region and hypothesis-generating interviews identified common exposures to aquatic facilities. We conducted a case-control study to determine exposure source(s) and facilitate control measures. Laboratory-confirmed cases of cryptosporidiosis from the region of interest notified between 1 March and 23 April 2015 were included. Controls residing in the same region were recruited from participants in a population health survey and frequency matched (2 per case) by age group. Details of exposure to potential risk factors were collected using a standardised telephone questionnaire for the 14-days prior to illness for cases, and an analogous exposure period for controls. Univariable and multivariable logistic regression were used to determine risk factors associated with illness using STATA SE 13.1. Thirty cases and 66 controls were included in the study. Half the cases were less than 12 years of age and 62% were female. Illness was most strongly associated with recreational water exposure at any waterpark (adjusted odds ratio (aOR)=73.5; 95% confidence interval (CI):6.74-802), and specifically at Victorian waterparks (aOR=45.6; 95% CI:5.20-399). Cases were linked with attendance at either a waterpark in the region or an adjacent region. As a result of this investigation, hyperchlorination was completed at identified facilities and swim hygiene information distributed. This study reinforces the potential for recreational water facilities, particularly waterparks, to act as a transmission source of Cryptosporidium infections. Continued communication to patrons is required to ensure healthy swimming practice in Victorian aquatic facilities.

Risk and protective factors for spasmodic dysphonia: a case-control investigation.

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Tanner, Kristine; Roy, Nelson; Merrill, Ray M; Kimber, Kamille; Sauder, Cara; Houtz, Daniel R; Doman, Darrin; Smith, Marshall E

2011-01-01

Spasmodic dysphonia (SD) is a chronic, incurable, and often disabling voice disorder of unknown pathogenesis. The purpose of this study was to identify possible endogenous and exogenous risk and protective factors uniquely associated with SD. Prospective, exploratory, case-control investigation. One hundred fifty patients with SD and 150 medical controls (MCs) were interviewed regarding their personal and family histories, environmental exposures, illnesses, injuries, voice use patterns, and general health using a previously vetted and validated epidemiologic questionnaire. Odds ratios and multiple logistic regression analyses (α<0.15) identified several factors that significantly increased the likelihood of having SD. These factors included (1) a personal history of mumps, blepharospasm, tremor, intense occupational and avocational voice use, and a family history of voice disorders; (2) an immediate family history of meningitis, tremor, tics, cancer, and compulsive behaviors; and (3) an extended family history of tremor and cancer. SD is likely multifactorial in etiology, involving both genetic and environmental factors. Viral infections/exposures, along with intense voice use, may trigger the onset of SD in genetically predisposed individuals. Future studies should examine the interaction among genetic and environmental factors to determine the pathogenesis of SD. Copyright © 2011 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

A case-control study of Yersinia enterocolitica infections in Auckland.

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Satterthwaite, P; Pritchard, K; Floyd, D; Law, B

1999-10-01

To identify major risk factors for Yersinia enterocolitica (YE) and identify measures to reduce YE infections. A prospective case control study, group age matched, using 186 cases of YE identified by community pathology laboratories and 379 randomly selected controls. Conducted between April 1995 and June 1996 in Auckland, New Zealand. Face-to-face interviews used a standardised questionnaire examining exposures to factors potentially associated with YE infections including untreated water, unreticulated sewerage, consumption of selected foods, selected food handling practices and socio-demographic factors. Multivariate logistic regression was used to calculate adjusted odds ratios for the potential risk factors. Population attributable risk (PAR) was calculated for significant exposures. Having more than two people living in the home was more common among cases than controls (OR = 2.2). Town supply water (OR = 0.2), reticulated sewerage (OR = 0.34) and looking after a young child (OR = 0.51) were significantly less common. Of the meats, only pork (OR = 1.34) had a higher consumption rate, while bacon (OR = 0.75) and smallgoods (OR = 0.73) were consumed less frequently by cases than controls. Eating food from a sandwich bar was more frequent among cases (OR = 1.18). Fruit and vegetable consumption was marginally less (OR = 0.98). The population attributable risk of these factors was 0.89, implying that 89% of YE would be eliminated if adverse exposures were removed. The risk of YE illness is increased by contact with untreated water, unreticulated sewerage and consumption of pork. Investigation of non-town water supply, informal sewerage systems and methods of preparation and consumption of pork are recommended to determine how YE enters the human food chain.

Gingivitis and periodontitis as a risk factor for stroke: A case-control study in the Iranian population.

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Hashemipour, Maryam Alsadat; Afshar, Afsaneh Jahanshahi; Borna, Roya; Seddighi, Behnas; Motamedi, Amin

2013-09-01

Periodontitis and gingivitis are one of the most infectious diseases in human. Several studies have been carried out on dependence of periodontitis and stroke. The aim of this study was to investigate the gingivitis and periodontitis as a risk factor for stroke in Iranian population. A case-control study was conducted on 100 patients suffering from stroke as case group, and 100 hospitalized patients as control group. The case group included 42 males and 58 females, and in control group there were 44 males and 56 females. Using a University of North Carolina-15 manual probe, the clinical attachment level, the distance between the cemento-enamel junction and the probed base of the periodontal pocket, were recorded by gingival and periodontal indexes. The data were analyzed by multiple logistic regressions, Chi-square test, Fisher's test, t-test, Man Whitney, and SPSS11.5 software program. P > 0.05 was considered as significant. The case group included 42 males and 58 females, and in control group 44 males and 56 females were included. In this investigation, the average of gingival index in men and women of case group was 1.22 ± 0.55 and 1.31 ± 0.55, respectively. This study showed that the average of gingival index in case group was more than control group. Periodontal index in both groups in men was more than women. The moderate and severe periodontitis in case group were more than that of control group (P = 0.003, P = 0.001). The result of this study shows that there is a significant relation between stroke and periodontal index; however, there isn't any significant relation between stroke and gingival index.

Case-control study on uveal melanoma (RIFA: rational and design

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Schmidt-Pokrzywniak Andrea

2004-08-01

Full Text Available Abstract Background Although a rare disease, uveal melanoma is the most common primary intraocular malignancy in adults, with an incidence rate of up to 1.0 per 100,000 persons per year in Europe. Only a few consistent risk factors have been identified for this disease. We present the study design of an ongoing incident case-control study on uveal melanoma (acronym: RIFA study that focuses on radiofrequency radiation as transmitted by radio sets and wireless telephones, occupational risk factors, phenotypical characteristics, and UV radiation. Methods/Design We conduct a case-control study to identify the role of different exposures in the development of uveal melanoma. The cases of uveal melanoma were identified at the Division of Ophthalmology, University of Essen, a referral centre for tumours of the eye. We recruit three control groups: population controls, controls sampled from those ophthalmologists who referred cases to the Division of Ophthalmology, University of Duisburg-Essen, and sibling controls. For each case the controls are matched on sex and age (five year groups, except for sibling controls. The data are collected from the study participants by short self-administered questionnaire and by telephone interview. During and at the end of the field phase, the data are quality-checked. To estimate the effect of exposures on uveal melanoma risk, we will use conditional logistic regression that accounts for the matching factors and allows to control for potential confounding.

Struggling doctors in specialist training: a case control study

DEFF Research Database (Denmark)

O'Neill, Lotte; Norberg, Karen; Thomsen, Maria

), or transferred (i.e. had unplanned changes in place of training/ward due to failure to thrive or due to inadequate development of competences), or dropped out (i.e. were dismissed from, had resigned from, or changed their speciality). Controls were a random sample of doctors in the source population, who were......Abstract summary The aim of this cummulative incidence case-control study was to examine: if struggling trainees in medical specialist training (cases) tended to struggle already in medical school or not compared to non-struggling controls, and which performance indicators during medical school...... seemed to predict struggling in postgraduate education if any. The study design is rooted in epidemiological methodology. Struggling doctors in specialist training: a case-control study. It has been reported in the international literature, that around 3-10% of doctors in post-garduate specialist...

Cardiovascular drugs and the risk of suicide: a nested case-control study

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Callréus, Torbjörn; Agerskov Andersen, Ulla; Hallas, Jesper

2007-01-01

OBJECTIVE: During the past 30 years, various cardiovascular drugs have been implicated as causes of depression or suicide. Although the evidence for causal relationships has generally been conflicting, both beta-blockers and angiotensin-converting-enzyme inhibitors (ACE-inhibitors) have been...... related to depression. Lipid-lowering therapies and calcium-channel blockers have also been linked to an increased risk of suicide. In this study, we investigated the possible association between the use of cardiovascular drugs and suicide using population-based register data. METHODS: We performed...... a nested case-control study in the county of Funen, Denmark, that consisted of 743 cases of completed suicide identified in a Death Registry for the period 1991-1998 and 14,860 age- and sex-matched controls. Information on previous drug use was retrieved from prescription data and the association between...

Residential traffic noise exposure and vestibular schwannoma - a Danish case-control study.

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Roswall, Nina; Stangerup, Sven-Eric; Cayé-Thomasen, Per; Schüz, Joachim; Johansen, Christoffer; Jensen, Steen Solvang; Raaschou-Nielsen, Ole; Sørensen, Mette

2017-10-01

Few risk factors for sporadic vestibular schwannoma (VS) are known. Several studies have proposed an increased risk with occupational noise exposure, whereas no studies have investigated residential traffic noise exposure as a risk factor. The present study investigated if residential traffic noise was associated with vestibular schwannoma in a large, population-based Danish case-control study. We identified 1454 VS cases, age above 30 years at diagnosis, between 1990 and 2007. For each case, we selected two random population controls, matched on sex and year of birth. Road and railway traffic noise at the residence was calculated for all present and historical addresses between 1987 and index date. Associations between traffic noise and risk for VS were estimated using conditional logistic regression, adjusted for education, disposable personal income, cohabitation status, railway noise exposure, municipal population density, and municipal income. A two-year time-weighted mean road traffic noise exposure was associated with an adjusted odds ratio of 0.92 (0.82-1.03) for developing VS, per 10 dB increment. There was no clear trend in categorical analyses. Similarly, linear and categorical analyses of residential railway noise did not suggest an association. We found no interaction with demographics, year of diagnosis, individual and municipal socioeconomic variables, and railway noise exposure. The results did not differ by tumor side, spread or size. The present study does not suggest an association between residential traffic noise and VS.

Patterned genital injury in cases of rape - A case-control study

DEFF Research Database (Denmark)

Astrup, Birgitte Schmidt; Ravn, Pernille; Thomsen, Jørgen Lange

2013-01-01

A pattern of genital injury that separates trauma seen in sexual assault cases from trauma seen following consensual sexual intercourse has been a matter of debate. This study aimed at clarifying the question by eliminating as many confounders as possible in a prospective, case-control setup. A t...

Identification and medical utilization of incident cases of alcohol dependence: A population-based case-control study.

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Pan, Chun-Hung; Li, Min-Shan; Yang, Tien-Wey; Huang, Ming-Chyi; Su, Sheng-Shiang; Hung, Yen-Ni; Chen, Chiao-Chicy; Kuo, Chian-Jue

2018-05-05

Patients with alcohol dependence (AD) often seek help from medical professionals due to alcohol-related diseases, but the overall distribution of medical specialties identifying new AD cases is unclear. We investigated how such cases were identified and how medical resources were utilized before the identification of AD in a nationwide cohort. We enrolled a population-based cohort (N = 1,000,000) using the National Health Insurance Research Database of Taiwan; 8181 cases with incident AD were retrieved between January 1, 2000, and December 31, 2010. For this nested case-control study, four controls were matched for age and sex with each case based on risk-set sampling. We measured various dimensions of medical utilization before AD was diagnosed, including department visited, physical comorbidity, and medication used. Conditional logistic regression was used for estimating the variables associated with AD. Patients living in less urbanized areas who were unemployed were more likely to develop AD. The highest proportions (34.2%) of AD cases were identified in the internal medicine department, followed by the emergency (22.3%) and psychiatry (18.7%) departments. AD patients had a higher risk of comorbid chronic hepatic disease (adjusted RR = 2.72, p identification of AD than controls. AD patients also had greater numbers of hospital admissions than controls, including non-psychiatric and psychiatric hospitalizations. Outpatient visit numbers were similar for AD patients and controls. The findings indicate that clinicians providing care in diverse medical settings should be prepared to screen for unhealthy alcohol use and to mitigate its detrimental effects. Copyright © 2018 Elsevier B.V. All rights reserved.

Weight, height, body mass index and risk of breast cancer in postmenopausal women: a case-control study

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Vahdaninia Mariam

2008-09-01

Full Text Available Abstract Background Many women in Iran have a relatively high body mass index. To investigate whether the condition contributes to excess breast cancer cases, a case-control study was conducted to assess the relationships between anthropometric variables and breast cancer risk in Tehran, Iran. Methods All incident cases of breast cancer in the Iranian Centre for Breast Cancer (ICBC were identified through the case records. Eligible cases were all postmenopausal women with histological confirmed diagnosis of breast cancer during 1996 to year 2000. Controls were randomly selected postmenopausal women attending the ICBC for clinical breast examination during the same period. The body mass index (BMI was calculated based on weights and heights as measured by the ICBC nursing staff. Both tests for trend and logistic regression analysis were performed to calculate odds ratios and 95% confidence intervals as measures of relative risk. Results In all, 116 breast cancer cases and 116 controls were studied. There were no significant differences between cases and control with regard to most independent variables studied. However, a significant difference was observed between cases and controls indicating that the mean BMI was higher in cases as compared to controls (P = 0.004. Performing logistic regression analysis while controlling for age, age at menopause, family history of breast cancer and parity, the results showed that women with a BMI in the obese range had a three fold increased risk of breast cancer [odds ratio (OR = 3.21, 95% confidence interval (CI: 1.15–8.47]. Conclusion The results suggest that obesity in postmenopausal women could increase risk of breast cancer and it merits further investigation in populations such as Iran where it seems that many women are short in height, and have a relatively high body mass index.

Sensory impairments and wrist fractures: A case-control study

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Bergthora Baldursdottir

2017-12-01

Full Text Available Objectives: To investigate vestibular function, foot sensation, postural control and functional abilities, and to evaluate whether these variables are associated with fall-related wrist fracture. Methods: A case-control study was conducted with 98 subjects, age range 50–75 years, who had sustained a fall-related wrist fracture. Forty-eight sex-, age- and physical activity-matched individuals, with no previous history of wrist fracture, served as controls. Measurements included: head-shake test (HST, tuning fork, biothesiometer, Semmes-Weinstein monofilaments (MF, Sensory Organization Test (SOT, Five-Times-Sit-to-Stand Test (FTSTS, 10-m walk test (10MWT, Activities-specific Balance Confidence (ABC, and the Dizziness Handicap Inventory (DHI scales. Logistic regression models were used to determine associations of variables with a fall-related wrist fracture. Results: Vestibular asymmetry was apparent in 82% of wrist fracture subjects and 63% of controls (p = 0.012. Plantar pressure sensation (p <0.001, SOT composite scores (p < 0.001, 10MWT (p <0.001, FTSTS (p <0.001, ABC (p <0.001 and DHI (p <0.005 were significantly poorer among cases than controls. A positive HST (odds ratio (OR 5.424; p = 0.008 and monofilament sensation (OR 3.886; p = 0.014 showed the strongest associations with having a fall-related wrist fracture. Conclusion: Asymmetrical vestibular function and reduced plantar pressure sensation are associated with fall-related wrist fractures among the ageing population. These factors are potential targets for future interventions.

Splenectomy Correlates With Increased Risk of Acute Pancreatitis: A Case-Control Study in Taiwan

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Lai, Shih-Wei; Lin, Cheng-Li; Liao, Kuan-Fu

2016-01-01

Objective The objective of the study was to investigate the association between splenectomy and acute pancreatitis. Methods We conducted a case-control study using the database of the Taiwan National Health Insurance Program. We included 7666 subjects aged 20–84 years with first-time acute pancreatitis during the period of 1998–2011 as cases and 30 664 randomly selected subjects without acute pancreatitis as controls. Both cases and controls were matched for sex, age, and index year of acute pancreatitis diagnosis. The association of acute pancreatitis with splenectomy was examined using a multivariable unconditional logistic regression model and reported as an odds ratio and its 95% confidence interval (CI). Results After adjustment for covariables, the adjusted odds ratio of acute pancreatitis was 2.90 for subjects with splenectomy (95% CI, 1.39–6.05) compared with subjects without splenectomy. Conclusions Splenectomy is associated with acute pancreatitis. Further studies are necessary to clarify the underlying mechanism. PMID:27087607

Outbreak of acute renal failure in Panama in 2006: a case-control study.

Science.gov (United States)

Rentz, E Danielle; Lewis, Lauren; Mujica, Oscar J; Barr, Dana B; Schier, Joshua G; Weerasekera, Gayanga; Kuklenyik, Peter; McGeehin, Michael; Osterloh, John; Wamsley, Jacob; Lum, Washington; Alleyne, Camilo; Sosa, Nestor; Motta, Jorge; Rubin, Carol

2008-10-01

In September 2006, a Panamanian physician reported an unusual number of patients with unexplained acute renal failure frequently accompanied by severe neurological dysfunction. Twelve (57%) of 21 patients had died of the illness. This paper describes the investigation into the cause of the illness and the source of the outbreak. Case-control and laboratory investigations were implemented. Case patients (with acute renal failure of unknown etiology and serum creatinine > 2 mg/dl) were individually matched to hospitalized controls for age (+/- 5 years), sex and admission date (< 2 days before the case patient). Questionnaire and biological data were collected. The main outcome measure was the odds of ingesting prescription cough syrup in cases and controls. Forty-two case patients and 140 control patients participated. The median age of cases was 68 years (range: 25-91 years); 64% were male. After controlling for pre-existing hypertension and renal disease and the use of angiotensin-converting enzyme inhibitors, a significant association was found between ingestion of prescription cough syrup and illness onset (adjusted odds ratio: 31.0, 95% confidence interval: 6.93-138). Laboratory analyses confirmed the presence of diethylene glycol (DEG) in biological samples from case patients, 8% DEG contamination in cough syrup samples and 22% contamination in the glycerin used to prepare the cough syrup. The source of the outbreak was DEG-contaminated cough syrup. This investigation led to the recall of approximately 60 000 bottles of contaminated cough syrup, widespread screening of potentially exposed consumers and treatment of over 100 affected patients.

Case-control study of amyotrophic lateral sclerosis

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Deapen, D.M.; Henderson, B.E.

1986-05-01

The authors conducted a study of 518 amyotrophic lateral sclerosis patients identified between 1977 and 1979 and 518 controls to investigate putative risk factors for this disease. Occupations at risk of electrical exposure were reported more often by patients (odds ratio (OR) = 3.8, 95% confidence interval (CI) = 1.4-13.0) as were electrical shocks producing unconsciousness (OR = 2.8, 95% CI = 1.0-9.9). Although an overall excess of physical trauma associated with unconsciousness was observed in the amyotrophic lateral sclerosis patients (OR = 1.6, 95% CI = 1.0-2.4), the effect was inversely associated with duration of the unconscious episodes, suggesting an effect of recall bias. Only slight differences were found for surgical traumata to the nervous system. Parkinsonism was reported more often among first degree relatives of cases (OR = 2.7, 95% CI = 1.1-7.6). The frequencies of prior poliomyelitis or other central nervous system diseases were similar for patients and controls. Occupational exposure to selected toxic substances was similar for patients and controls except for the manufacture of plastics (OR = 3.7, 95% CI = 1.0-20.5), although few details of these exposures were provided. No differences in occupations with exposure to animal skins or hides were observed.

Use of oral cholera vaccines in an outbreak in Vietnam: a case control study.

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Dang Duc Anh

Full Text Available BACKGROUND: Killed oral cholera vaccines (OCVs are available but not used routinely for cholera control except in Vietnam, which produces its own vaccine. In 2007-2008, unprecedented cholera outbreaks occurred in the capital, Hanoi, prompting immunization in two districts. In an outbreak investigation, we assessed the effectiveness of killed OCV use after a cholera outbreak began. METHODOLOGY/PRINCIPAL FINDINGS: From 16 to 28 January 2008, vaccination campaigns with the Vietnamese killed OCV were held in two districts of Hanoi. No cholera cases were detected from 5 February to 4 March 2008, after which cases were again identified. Beginning 8 April 2008, residents of four districts of Hanoi admitted to one of five hospitals for acute diarrhea with onset after 5 March 2008 were recruited for a matched, hospital-based, case-control outbreak investigation. Cases were matched by hospital, admission date, district, gender, and age to controls admitted for non-diarrheal conditions. Subjects from the two vaccinated districts were evaluated to determine vaccine effectiveness. 54 case-control pairs from the vaccinated districts were included in the analysis. There were 8 (15% and 16 (30% vaccine recipients among cases and controls, respectively. The vaccine was 76% protective against cholera in this setting (95% CI 5% to 94%, P = 0.042 after adjusting for intake of dog meat or raw vegetables and not drinking boiled or bottled water most of the time. CONCLUSIONS/SIGNIFICANCE: This is the first study to explore the effectiveness of the reactive use of killed OCVs during a cholera outbreak. Our findings suggest that killed OCVs may have a role in controlling cholera outbreaks.

Thyroid cancer in French Polynesia: a population based case control study

International Nuclear Information System (INIS)

Brindel, P.; Doyon, F.; Adjadj, E.; Vathaire, F. de; Drozdovitch, V.; Bouville, A.; Paoaafaite, J.; Teuri, J.

2006-01-01

Full text of publication follows: Because a previous study had shown that registered thyroid cancer incidence is higher among natives of French Polynesia (FP) than in other Maori populations from Hawaii and New-Zealand, a case-control study of thyroid cancer coordinated by Unit 605 of INSERM was conducted in FP. The main objective was to assess the potential role of atmospheric nuclear weapons tests performed by France between 1966 and 1974 on such a high incidence. The study included 600 subjects born and residing in FP: 229 cases of differentiated thyroid carcinoma diagnosed between 1979 and 2004, aged up to 30 years old at start of nuclear weapons testing and 371 control s matched on gender and birth date randomly selected from t he FP registry of births. Face to face interviews were conducted from 2002 to 2004 by specialized investigators native from FP who received a specific formation for this study. Addresses were collected from the territorial medical insurance, which covers all the inhabitants, whatever their professional status. Detailed information about nutrition at time of interview and at the end of adolescence was collected by means of a semi-quantitative method using pictures. Data concerning residence, hormonal and reproductive life, familial and personal background of thyroid pathologies and cancers, and professional and environmental exposure to carcinogens were also collected. For each study subject, radiation thyroid dose was estimated taking into account residential history and dietary habits of the subject and deposition densities of radionuclides reconstructed for each island where the subject resided during the testing period. The iodine intake will be estimated from the dietary questionnaire, as well as from mass-spectrometry measurements of stable iodine in nail clippings, which were collected during the interviews. Among the 229 cases, 89% were females, 54% declared themselves as of pure Maori origin, another 36% of Maori-Asian or Maori

Exposure to antiepileptic drugs and the risk of hip fracture: a case-control study

DEFF Research Database (Denmark)

Tsiropoulos, Ioannis; Andersen, Morten; Nymark, Tine

2008-01-01

PURPOSE: To investigate whether the use of antiepileptic drugs (AEDs) increases the risk of hip fracture. METHODS: We performed a case-control study using data from the Funen County (population 2004: 475,000) hip fracture register. Cases (n = 7,557) were all patients admitted to county hospitals...... with a hip fracture during the period 1996-2004. Controls (n = 27,575) were frequency matched by age and gender. Information on use of AEDs, other drugs, and hospital contacts was available from local registers. Odds ratios (ORs) with 95% confidence intervals (CI) for hip fracture were estimated...

Environment And Genetics in Lung cancer Etiology (EAGLE study: An integrative population-based case-control study of lung cancer

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Colombi Antonio

2008-06-01

Full Text Available Abstract Background Lung cancer is the leading cause of cancer mortality worldwide. Tobacco smoking is its primary cause, and yet the precise molecular alterations induced by smoking in lung tissue that lead to lung cancer and impact survival have remained obscure. A new framework of research is needed to address the challenges offered by this complex disease. Methods/Design We designed a large population-based case-control study that combines a traditional molecular epidemiology design with a more integrative approach to investigate the dynamic process that begins with smoking initiation, proceeds through dependency/smoking persistence, continues with lung cancer development and ends with progression to disseminated disease or response to therapy and survival. The study allows the integration of data from multiple sources in the same subjects (risk factors, germline variation, genomic alterations in tumors, and clinical endpoints to tackle the disease etiology from different angles. Before beginning the study, we conducted a phone survey and pilot investigations to identify the best approach to ensure an acceptable participation in the study from cases and controls. Between 2002 and 2005, we enrolled 2101 incident primary lung cancer cases and 2120 population controls, with 86.6% and 72.4% participation rate, respectively, from a catchment area including 216 municipalities in the Lombardy region of Italy. Lung cancer cases were enrolled in 13 hospitals and population controls were randomly sampled from the area to match the cases by age, gender and residence. Detailed epidemiological information and biospecimens were collected from each participant, and clinical data and tissue specimens from the cases. Collection of follow-up data on treatment and survival is ongoing. Discussion EAGLE is a new population-based case-control study that explores the full spectrum of lung cancer etiology, from smoking addiction to lung cancer outcome, through

A case-control study of risk factors for bovine cysticercosis in Danish cattle herds

DEFF Research Database (Denmark)

Calvo Artavia, Francisco Fernando; Nielsen, Liza Rosenbaum; Dahl, J.

2013-01-01

than in countries with few lightly infected cases per year. The aim of the present case-control study was to quantify associations between potential herd-level risk factors and BC in Danish cattle herds. Risk factors can be used in the design of a risk-based meat inspection system targeted towards...... a questionnaire and register data from the Danish Cattle Database were grouped into meaningful variables and used to investigate the risk factors for BC using a multivariable logistic regression model. Case herds were almost three times more likely than control herds to let all or most animals out grazing. Case...... the animals with the highest risk of BC. Cases (n = 77) included herds that hosted at least one animal diagnosed with BC at meat inspection, from 2006 to 2010. Control herds (n = 231) consisted of randomly selected herds that had not hosted any animals diagnosed with BC between 2004 and 2010. The answers from...

Investigating Science Collaboratively: A Case Study of Group Learning

Science.gov (United States)

Zinicola, Debra A.

2009-01-01

Discussions of one urban middle school group of students who were investigating scientific phenomena were analyzed; this study was conducted to discern if and how peer interaction contributes to learning. Through a social constructivist lens, case study methodology, we examined conceptual change among group members. Data about science talk was…

Potential of public transit as a transportation control measure: Case studies

Energy Technology Data Exchange (ETDEWEB)

Sillings, M.

1998-07-01

This report is the final product of the Clean Air Project of the National Association of Regional Councils/NARC. It documents a nationwide study of transit projects and programs initiated in the wake of the 1990 Clean Air Act Amendments/CAAA and the Intermodal Surface Transportation Efficiency Act of 1991/ISTEA. The study purpose was to assess the experience, limitations, and value of public transit as a potential transportation control measure/TCM, i.e., generates significant air quality benefits by eliminating or reducing emissions from motor vehicles. Four in-depth case studies and six additional projects featured as innovations in transportation are offered as examples investigating the potential of transit as a TCM. These case studies and innovations highlight the efforts of ten metropolitan areas and transit agencies which have succeed in developing and implementing innovative transit strategies.

The Misconception of Case-Control Studies in the Plastic Surgery Literature: A Literature Audit.

Science.gov (United States)

Hatchell, Alexandra C; Farrokhyar, Forough; Choi, Matthew

2017-06-01

Case-control study designs are commonly used. However, many published case-control studies are not true case-controls and are in fact mislabeled. The purpose of this study was to identify all case-control studies published in the top three plastic surgery journals over the past 10 years, assess which were truly case-control studies, clarify the actual design of the articles, and address common misconceptions. MEDLINE, Embase, and Web of Science databases were searched for case-control studies in the three highest-impact factor plastic surgery journals (2005 to 2015). Two independent reviewers screened the resulting titles, abstracts, and methods, if applicable, to identify articles labeled as case-control studies. These articles were appraised and classified as true case-control studies or non-case-control studies. The authors found 28 articles labeled as case-control studies. However, only six of these articles (21 percent) were truly case-control designs. Of the 22 incorrectly labeled studies, one (5 percent) was a randomized controlled trial, three (14 percent) were nonrandomized trials, two (9 percent) were prospective comparative cohort designs, 14 (64 percent) were retrospective comparative cohort designs, and two (9 percent) were cross-sectional designs. The mislabeling was worse in recent years, despite increases in evidence-based medicine awareness. The majority of published case-control studies are not in fact case-control studies. This misunderstanding is worsening with time. Most of these studies are actually comparative cohort designs. However, some studies are truly clinical trials and thus a higher level of evidence than originally proposed.

A case-control study assessing depression in patients with periodontitis

Directory of Open Access Journals (Sweden)

Shiyamali Sundararajan

2017-01-01

Full Text Available Background: Chronic periodontitis is an inflammatory disease of the supporting structures of the tooth. One of the important non-oral risk factors for periodontitis is psychosocial stress and depression. Depression affects oral health by affecting the immune system through its effects on hypothalamic pituitary axis system. Periodontal inflammatory surface area (PISA is a system used to assess inflammatory burden in the periodontal tissue. Aim: The aim of this study is to assess the relationship between PISA and depression. Settings and Design: The design of the study is case-control study. Materials and Methods: The study design is a case-control study with forty patients each in case and control groups. The periodontal inflammatory level was assessed by PISA system and the levels of depression was assessed by using Beck's Depression Inventory (BDI. Statistical Analysis: Student's t-test was used to compare PISA and BDI scores. The BDI score (mean ± standard deviation [SD] for controls was 12.75 ± 6.82 compared to 22.73 ± 4.40 for the cases. The comparison (t = 7.78 was statistically significant at P < 0.0001. The PISA score (mean ± SD for controls was 210.47 ± 76.80 compared to the PISA score of 1069.50 ± 204.21 for cases which was statistically significant (t = 24.90; P < 0.0001. Results: Significantly higher BDI scores were observed in patients with chronic periodontitis than healthy controls. Conclusion: This study clearly reveals a significant association between the severity of depression and inflammatory burden.

Two-stage case-control association study of dopamine-related genes and migraine

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Pardo Julio

2009-09-01

Full Text Available Abstract Background We previously reported risk haplotypes for two genes related with serotonin and dopamine metabolism: MAOA in migraine without aura and DDC in migraine with aura. Herein we investigate the contribution to migraine susceptibility of eight additional genes involved in dopamine neurotransmission. Methods We performed a two-stage case-control association study of 50 tag single nucleotide polymorphisms (SNPs, selected according to genetic coverage parameters. The first analysis consisted of 263 patients and 274 controls and the replication study was composed by 259 cases and 287 controls. All cases were diagnosed according to ICHD-II criteria, were Spanish Caucasian, and were sex-matched with control subjects. Results Single-marker analysis of the first population identified nominal associations of five genes with migraine. After applying a false discovery rate correction of 10%, the differences remained significant only for DRD2 (rs2283265 and TH (rs2070762. Multiple-marker analysis identified a five-marker T-C-G-C-G (rs12363125-rs2283265-rs2242592-rs1554929-rs2234689 risk haplotype in DRD2 and a two-marker A-C (rs6356-rs2070762 risk haplotype in TH that remained significant after correction by permutations. These results, however, were not replicated in the second independent cohort. Conclusion The present study does not support the involvement of the DRD1, DRD2, DRD3, DRD5, DBH, COMT, SLC6A3 and TH genes in the genetic predisposition to migraine in the Spanish population.

Ultrasound biomicroscopy and iris pigment dispersion: a case--control study.

Science.gov (United States)

Mora, P; Sangermani, C; Ghirardini, S; Carta, A; Ungaro, N; Gandolfi, Sa

2010-04-01

The study involved eyes affected by pigment dispersion syndrome (PDS) or pigmentary glaucoma (PG) investigated by ultrasound biomicroscopy (UBM). Different irido-corneal parameters were assessed and compared with those from healthy controls. The aim was to investigate the capacity of the UBM in differentiating the cases and, potentially, in confirming the pathogenic mechanisms. Patients with a first diagnosis of PDS or PG were included. A cohort of healthy volunteers matched for sex, age and refractive errors was recruited. All underwent UBM examination: the following parameters were assessed in relaxed and stimulated accommodative state in one eye: iris-lens contact (ILC), irido-corneal angle (ICA) and iris concavity (IC). A receiver operating characteristic (ROC) analysis assessed the ability of UBM to discriminate between subjects with and without PDS/PG. There were 24 eyes in the case group: four diagnosed as PG and the remaining 20 as PDS. There were 25 eyes in the control group. The two groups were statistically superimposable except for baseline intraocular pressure, which was higher in the case group (p=0.0001). All UBM parameters were statistically different between the two groups. ICA in near vision was the best-performing parameter, reaching a sensitivity (=specificity) of 0.875 with a cut-off at 53.0 degrees . The second most sensitive parameter was IC, still in near vision. All UBM parameters examined were statistically different between the two groups. ROC analysis showed ICA and IC in near vision to be the most discriminatory parameters. This evidence confirms the importance of iris movements in inducing the particular features of PDS/PG.

The Glioma International Case-Control Study

DEFF Research Database (Denmark)

Amirian, E. Susan; Armstrong, Georgina N; Zhou, Renke

2016-01-01

Decades of research have established only a few etiological factors for glioma, which is a rare and highly fatal brain cancer. Common methodological challenges among glioma studies include small sample sizes, heterogeneity of tumor subtypes, and retrospective exposure assessment. Here, we briefly...... describe the Glioma International Case-Control (GICC) Study (recruitment, 2010-2013), a study being conducted by the Genetic Epidemiology of Glioma International Consortium that integrates data from multiple data collection sites, uses a common protocol and questionnaire, and includes biospecimen...

Mild asthma and chronic bronchitis seem to influence functional exercise capacity: a multi-case control study.

Science.gov (United States)

Marcon, Alessandro; Girardi, Paolo; Ferrari, Marcello; Olivieri, Mario; Accordini, Simone; Bombieri, Cristina; Bortolami, Oscar; Braggion, Marco; Cappa, Veronica; Cazzoletti, Lucia; Locatelli, Francesca; Nicolis, Morena; Perbellini, Luigi; Sembeni, Silvia; Verlato, Giuseppe; Zanolin, Maria Elisabetta; de Marco, Roberto

2013-01-01

In the Genes Environment Interaction in Respiratory Diseases population-based multi-case control study, we investigated whether asthma, chronic bronchitis (CB) and rhinitis were associated with a reduced 6-minute walk distance (6MWD), and whether the 6MWD determinants were similar for subjects with/without respiratory diseases. Cases of asthma (n = 360), CB (n = 120), rhinitis (n = 203) and controls (no respiratory diseases: n = 302) were recruited. The variation in the 6MWD across the groups was analyzed by ANCOVA, adjusting for gender, age, height, weight and comorbidity. The 6MWD determinants were studied by linear regression, and heterogeneity across the cases and controls was investigated. The 6MWD differed across cases and controls (p = 0.01). It was shorter for cases of asthma (-17.1, 95% CI -28.3 to -5.8 m) and CB (-20.7, 95% CI: -36.6 to -4.8 m) than for controls (604 ± 68 m on average), but not for cases of rhinitis. The negative association between age and the 6MWD was significant for cases of CB, but not for the other groups (p = 0.001). Even at the level of severity found in the general population, asthma and CB could influence the 6MWD, which seems to reflect the functional exercise level for daily physical activities. The negative association between ageing and the 6MWD was particularly strong in subjects with CB. Our report adds to the mounting evidence that CB is not a trivial condition, especially in the ageing adult population, and it supports the importance of monitoring functional capacity and of physical reconditioning in mild asthma. Copyright © 2013 S. Karger AG, Basel.

Toxocara infection in psychiatric inpatients: a case control seroprevalence study.

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Cosme Alvarado-Esquivel

Full Text Available BACKGROUND: There is poor knowledge about the epidemiology of toxocariasis in psychiatric patients. AIMS: Determine the seroepidemiology of Toxocara infection in psychiatric patients. METHODS: Through a case-control seroprevalence study, 128 psychiatric inpatients and 276 control subjects were compared for the presence of anti-Toxocara IgG antibodies in Durango, Mexico. Socio-demographic, clinical, and behavioral characteristics of inpatients associated with toxocariasis were also investigated. RESULTS: Six of the 128 (4.7% psychiatric inpatients, and 3 (1.1% of the 276 controls were positive for anti-Toxocara IgG antibodies (P = 0.03. Stratification by age showed that Toxocara seroprevalence was significantly (P = 0.02 higher in patients aged ≤50 years old (6/90∶6.7% than controls of the same age (2/163∶1.2%. While Toxocara seroprevalence was similar in patients and controls aged >50 years old. Stratification by gender showed that Toxocara seroprevalence was significantly (P = 0.03 higher in female patients (2/37∶5.4% than in female controls (0/166∶0%. No statistically significant associations between Toxocara seropositivity and clinical characteristics were found. In contrast, Toxocara seropositivity was associated with consumption of goat meat and raw sea snail. CONCLUSIONS: This is the first report of toxocariasis in psychiatric inpatients in Mexico. Further studies with larger sample sizes are needed to elucidate the association of toxocariasis with psychiatric diseases. The role of the consumption of goat meat and raw sea snail in the transmission of Toxocara deserve further investigation.

Colon cancer controls versus population controls in case-control studies of occupational risk factors

DEFF Research Database (Denmark)

Kaerlev, Linda; Lynge, Elsebeth; Sabroe, Svend

2004-01-01

are interchangeable with the experience for population controls. Patient controls may even be preferable from population controls under certain conditions. In this study we examine if colon cancer patients can serve as surrogates for proper population controls in case-control studies of occupational risk factors...... about occupational, medical and life style conditions. RESULTS: No statistical significant difference for educational level, medical history or smoking status was seen between the two control groups. There was evidence of a higher alcohol intake, less frequent work as a farmer and less exposure...... to pesticides among colon cancer controls. CONCLUSIONS: Use of colon cancer controls may provide valid exposure estimates in studies of many occupational risk factors for cancer, but not for studies on exposure related to farming....

A population-based case-control study on statin exposure and risk of acute diverticular disease.

Science.gov (United States)

Sköldberg, Filip; Svensson, Tobias; Olén, Ola; Hjern, Fredrik; Schmidt, Peter T; Ljung, Rickard

2016-01-01

A reduced risk of perforated diverticular disease among individuals with current statin exposure has been reported. The aim of the present study was to investigate whether statins reduce the risk of acute diverticular disease. A nation-wide population-based case-control study was performed, including 13,127 cases hospitalised during 2006-2010 with a first-time diagnosis of colonic diverticular disease, and 128,442 control subjects (matched for sex, age, county of residence and calendar year). Emergency surgery, assumed to be a proxy for complicated diverticulitis, was performed on 906 of the cases during the index admission, with 8818 matched controls. Statin exposure was classified as "current" or "former" if a statin prescription was last dispensed ≤ 125 days or >125 days before index date, respectively. The association between statin exposure and acute diverticular disease was investigated by conditional logistic regression, including models adjusting for country of birth, educational level, marital status, comorbidities, nonsteroidal anti-inflammatory drug/steroid exposure and healthcare utilisation. A total of 1959 cases (14.9%) and 16,456 controls (12.8%) were current statin users (crude OR 1.23 [95% CI 1.17-1.30]; fully adjusted OR 1.00 [0.94-1.06]). One hundred and thirty-two of the cases subjected to surgery (14.6%), and 1441 of the corresponding controls (16.3%) were current statin users (crude OR 0.89 [95% CI 0.73-1.08]; fully adjusted OR 0.70 [0.55-0.89]). The results do not indicate that statins affect the development of symptomatic diverticular disease in general. However, current statin use was associated with a reduced risk of emergency surgery for diverticular disease.

Case-control study of lung cancer among workers at a uranium processing plant

International Nuclear Information System (INIS)

Cookfair, D.L.

1982-01-01

The purpose of this case-control study was to investigate the relationship between exposure to radiation resulting from the inhalation of uranium dust and the dust of uranium-bearing compounds and death due to lung cancer. Cases and controls were chosen from a cohort of white male workers employed at one uranium processing plant during World War II. The 330 cases consisted of all lung cancer deaths occurring in the cohort between 1943 and 1973. Level of exposure to radiation and other potential workplace carcinogens was determined for each worker using process manuals, industrial hygiene reports, air monitoring data and individual work histories. Smoking status and information regarding medical variables was determined from employee medical records. Cumulative radiation lung dose among study population members ranged from 0 to 75 rads. Data were analyzed using Mantel-Haenszel stratified analysis and logistic regression. Relative risk was found to increase with increasing level of lung dose exposure even after controlling for age, smoking status and other workplace exposures, but only for those who were over the age of 44 when first exposed. A statistically significant excess in risk was found for men in this hire age group with a cumulative lung dose of 20 rads or more. The risk associated with the overall work environment was also investigated using a summary measure of total workplace exposure called chemical rank. A similar relationship existed between chemical rank and lung cancer to that found for cumulative lung dose and lung cancer

Sustainability Strategy and Management Control Systems in Family Firms. Evidence from a Case Study

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Fabio Caputo

2017-06-01

Full Text Available The aim of this paper is to investigate how the integration of new forms of sustainable control systems (SCSs and traditional management control systems (MCSs, and the use of these control systems affect the integration of sustainability within organizational strategy. A qualitative case study based on a longitudinal investigation of an Italian family firm operating in an environment-sensitive context, the intermodal transport industry, has been used to trace the company’s pathway to sustainability integration based on the Gond et al. framework. The paper enriches the Gond et al. conceptualization providing evidence of the external and internal factors relevant in affecting the organization’s pathway towards sustainability integration. To the best of the authors’ knowledge, the present study is the first analysis that investigates the integration of sustainability into organizational strategy in the context of family firms, from the point of view of performance management systems (PMSs.

Medical records documentation of constipation preceding Parkinson disease: A case-control study.

Science.gov (United States)

Savica, R; Carlin, J M; Grossardt, B R; Bower, J H; Ahlskog, J E; Maraganore, D M; Bharucha, A E; Rocca, W A

2009-11-24

Parkinson disease (PD) may affect the autonomic nervous system and may cause constipation; however, few studies have explored constipation preceding the motor onset of PD. We investigated constipation preceding PD using a case-control study design in a population-based sample. Using the medical records-linkage system of the Rochester Epidemiology Project, we identified 196 subjects who developed PD in Olmsted County, MN, from 1976 through 1995. Each incident case was matched by age (+/-1 year) and sex to a general population control. We reviewed the complete medical records of cases and controls in the medical records-linkage system to ascertain the occurrence of constipation preceding the onset of PD (or index year). Constipation preceding PD or the index year was more common in cases than in controls (odds ratio [OR] 2.48; 95% confidence interval [CI] 1.49 to 4.11; p = 0.0005). This association remained significant after adjusting for smoking and coffee consumption (ever vs never), and after excluding constipation possibly induced by drugs. In addition, the association remained significant in analyses restricted to constipation documented 20 or more years before the onset of motor symptoms of PD. Although the association was stronger in women than in men and in patients with PD with rest tremor compared with patients with PD without rest tremor, these differences were not significant. Our findings suggest that constipation occurring as early as 20 or more years before the onset of motor symptoms is associated with an increased risk of Parkinson disease.

Occupational Lifting Tasks and Retinal Detachment in Non-Myopics and Myopics: Extended Analysis of a Case-control Study

OpenAIRE

Mattioli, Stefano; Curti, Stefania; De Fazio, Rocco; Cooke, Robin Mt; Zanardi, Francesca; Bonfiglioli, Roberta; Farioli, Andrea; Violante, Francesco S.

2012-01-01

Objectives: Lifting heavy weights involves the Valsalva manoeuvre, which leads to intraocular pressure spikes. We used data from a case-control study to further investigate the hypothesis that occupational lifting is a risk factor for retinal detachment. Methods: The study population included 48 cases (patients operated for retinal detachment) and 84 controls (outpatients attending an eye clinic). The odds ratios (OR) of idiopathic retinal detachment were estimated with a logistic regressi...

Thyrotropin receptor autoantibodies and early miscarriages in patients with Hashimoto thyroiditis: a case-control study.

Science.gov (United States)

Toulis, Konstantinos A; Goulis, Dimitrios G; Tsolakidou, Konstantina; Hilidis, Ilias; Fragkos, Marios; Polyzos, Stergios A; Gerofotis, Antonios; Kita, Marina; Bili, Helen; Vavilis, Dimitrios; Daniilidis, Michail; Tarlatzis, Basil C; Papadimas, Ioannis

2013-08-01

We have previously hypothesized that early miscarriage in women with Hashimoto thyroiditis might be the result of a cross-reactivity process, in which blocking autoantibodies against thyrotropin receptor (TSHr-Ab) antagonize hCG action on its receptor on the corpus luteum. To test this hypothesis from the clinical perspective, we investigated the presence of TSHr-Ab in Hashimoto thyroiditis patients with apparently unexplained, first-trimester recurrent miscarriages compared to that in Hashimoto thyroiditis patients with documented normal fertility. A total of 86 subjects (43 cases and 43 age-matched controls) were finally included in a case-control study. No difference in the prevalence of TSHr-Ab positivity was detected between cases and controls (Fisher's exact test, p value = 1.00). In patients with recurrent miscarriages, TSHr-Ab concentrations did not predict the number of miscarriages (univariate linear regression, p value = 0.08). These results were robust in sensitivity analyses, including only cases with full investigation or those with three or more miscarriages. We conclude that no role could be advocated for TSHr-Ab in the aetiology of recurrent miscarriages in women with Hashimoto thyroiditis.

Risk Factors for Anemia in Pregnancy: A Case Control Study

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Rutuja Pundkar

2017-12-01

Full Text Available Background: Aim of the study was to find the risk factors leading to Anemia in pregnancy. The main objective was to study the various sociodemographic factors leading to anemia. And to assess the knowledge about anemia among study participants. Material and methods: The present Case control study was carried out at Primary Health Centre, to determine the risk factors leading to anemia in pregnancy. A total of 308 pregnant females were registered. Among them two groups were made, group I cases and group II controls. Each group had 50 cases each. Laboratory test were done and females having hemoglobin less than 11mg/dl were considered anemic. Anemic females were considered cases and females having Hb >11mg/dl were considered controls. Data analysis was done using SPSS software. Results: The overall mean haemoglobin (Hb was 11.55g/dL in controls, whereas it was seen that among the cases it was 9.58g/dL.It would seem that diet, family size, education, social class, gravida and parity are associated with anemia in pregnancy. Conclusion: After adjusting for all the possible covariates there seems to be significant association between Hb levels and age group, education level, family size, diet, gravida and parity.

Risk factors associated with sick leave due to work-related injuries in Dutch farmers: an exploratory case-control study

NARCIS (Netherlands)

Hartman, E.; Frankena, K.; Oude Vrielink, H.H.E.; Nielen, M.; Metz, J.H.M.; Huirne, R.B.M.

2004-01-01

Using data from an insurance company, the occurrence of sick leave among Dutch farmers due to work-related injuries, and the epidemiological risk factors were investigated. In this case-control study the cases had filed a sick leave claim for work-related injury from 19982001 and the controls had

Correlation of Serum Zinc Level with Simple Febrile Seizures: A Hospital based Prospective Case Control Study

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Imran Gattoo

2015-04-01

Full Text Available Background: Febrile seizures are one of the most common neurological conditions of childhood. It seems that zinc deficiency is associated with increased risk of febrile seizures.Aim: To estimate the serum Zinc level in children with simple Febrile seizures and to find the correlation between serum zinc level and simple Febrile seizures.Materials and Methods: The proposed study was a hospital based prospective case control study which included infants and children aged between 6 months to 5 years, at Post Graduate Department of Pediatrics, (SMGS Hospital, GMC Jammu, northern India. A total of 200 infants and children fulfilling the inclusion criteria were included. Patients were divided into 100(cases in Group A with simple febrile seizure and 100(controls in Group B of children with acute febrile illness without seizure. All patients were subjected to detailed history and thorough clinical examination followed by relevant investigations.Results: Our study had slight male prepondance of 62% in cases and 58% in controls . Mean serum zinc level in cases was 61.53±15.87 ugm/dl and in controls it was 71.90+18.50 ugm/dl .Serum zinc level was found significantly low in cases of simple febrile seizures as compaired to controls ,with p value of

Investigation of established genetic risk variants for glioma in prediagnostic samples from a population-based nested case-control study.

Science.gov (United States)

Wibom, Carl; Späth, Florentin; Dahlin, Anna M; Langseth, Hilde; Hovig, Eivind; Rajaraman, Preetha; Johannesen, Tom Børge; Andersson, Ulrika; Melin, Beatrice

2015-05-01

Although glioma etiology is poorly understood in general, growing evidence indicates a genetic component. Four large genome-wide association studies (GWAS) have linked common genetic variants with an increased glioma risk. However, to date, these studies are based largely on a case-control design, where cases have been recruited at the time of or after diagnosis. They may therefore suffer from a degree of survival bias, introduced when rapidly fatal cases are not included. To confirm glioma risk variants in a prospective setting, we have analyzed 11 previously identified risk variants in a set of prediagnostic serum samples with 598 cases and 595 matched controls. Serum samples were acquired from The Janus Serum Bank, a Norwegian population-based biobank reserved for cancer research. We confirmed the association with glioma risk for variants within five genomic regions: 8q24.21 (CCDC26), 9p21.3 (CDKN2B-AS1), 11q23.3 (PHLDB1), 17p13.1 (TP53), and 20q13.33 (RTEL1). However, previously identified risk variants within the 7p11.2 (EGFR) region were not confirmed by this study. Our results indicate that the risk variants that were confirmed by this study are truly associated with glioma risk and may, consequently, affect gliomagenesis. Though the lack of positive confirmation of EGFR risk variants may be attributable to relatively limited statistical power, it nevertheless raises the question whether they truly are risk variants or markers for glioma prognosis. Our findings indicate the need for further studies to clarify the role of glioma risk loci with respect to prolonged survival versus etiology. ©2015 American Association for Cancer Research.

A case-control study of visual acuity in onychocryptosis.

LENUS (Irish Health Repository)

Hogan, Aisling M

2012-02-01

BACKGROUND: There are many theories surrounding the etiology of ingrown toenails (IGTN). Few factors have been formally assessed, but it is widely accepted that a poor nail cutting technique has a causative role. AIM: To investigate the hypothesis that decreased visual acuity may lead to inadequate nail cutting and the formation of IGTN. METHODS: A prospective case-control study was performed. Near and distance visual acuity were tested on a population with IGTN (n = 19) and compared with that of an age- and sex-matched control cohort (n = 24) who underwent epidermal cyst excision in the same tertiary referral center. Comparisons of visual acuity were made between groups by Mann-Whitney U-test. Differences were taken to be significant if P < 0.05. Institutional Review Board approval was sought and granted. RESULTS: No significant difference in visual acuity (near or distance) was demonstrated between patients with IGTN and the control group (P = 0.33). CONCLUSION: Visual acuity does not appear to play a significant role in the development of IGTN.

Relationship of Psychosocial Risk Factors, Certain Personality Traits and Myocardial Infarction in Indians: A Case-control Study.

Science.gov (United States)

Gupta, Rajni; Kishore, Jugal; Bansal, Yogesh; Daga, Mk; Jiloha, Rc; Singal, Rajeev; Ingle, Gk

2011-07-01

To investigate the relationship of psychosocial factors (lack of social support, stress and subjective well-being) and personality traits with myocardial infarction (MI). A case-control study involving 100 cases and 100 matched controls was conducted in Lok Nayak Hospital, New Delhi. Stress over 1 year was significantly higher in cases (P introvert (P < 0.001) personalities. Certain personality traits and recent stress may be important risk factors of MI, especially in Indians. The finding may have implications on the preventive strategies planned for MI patients.

A case-control study of the association between ulcerative colitis and hyperthyroidism in an Asian population.

Science.gov (United States)

Tsai, Ming-Chieh; Lin, Herng-Ching; Lee, Cha-Ze

2017-06-01

Ulcerative colitis (UC) is a chronic relapsing inflammatory disease with significant clinical diversity. However, the aetiology, pathogenesis and optimal treatment of UC remain unclear. The purpose of this case-control study was to investigate the association between previously diagnosed hyperthyroidism and UC using a large population-based data set in Taiwan. The data for this population-based case-control study were retrieved from the Taiwan Longitudinal Health Insurance Database 2005. We included 2709 patients with UC as cases and 8127 sex- and age-matched patients without UC as controls. A conditional logistic regression analysis was conducted to compute the odds ratio (OR) and corresponding 95% confidence interval (CI) for the association between UC and prior hyperthyroidism. We found that, in total, 327 of the 10 836 sampled patients (3.02%) had previously been diagnosed with hyperthyroidism. There was a higher proportion of prior hyperthyroidism among cases than controls (4.10% vs 2.66%, Phyperthyroidism was 1.57 (95% CI=1.24-1.98) compared to controls. Similarly, after adjusting for monthly income, geographic location and urbanization level, cases were still more likely to have previously been diagnosed with hyperthyroidism than controls (OR=1.61, 95% CI=1.27-2.05). Furthermore, we analysed the ORs of prior hyperthyroidism between cases and controls according to age group. We found that of the youngest group of sampled patients (18-39 years), cases had the greatest adjusted OR for having previously been diagnosed with hyperthyroidism than controls (OR=1.98, 95% CI=1.04-3.79). This study demonstrated an association between UC and hyperthyroidism. © 2017 John Wiley & Sons Ltd.

Use of a total traffic count metric to investigate the impact of roadways on asthma severity: a case-control study

Directory of Open Access Journals (Sweden)

deVos Annemarie JBM

2011-06-01

Full Text Available Abstract Background This study had two principal objectives: (i to investigate the relationship between asthma severity and proximity to major roadways in Perth, Western Australia; (ii to demonstrate a more accurate method of exposure assessment for traffic pollutants using an innovative GIS-based measure that fully integrates all traffic densities around subject residences. Methods We conducted a spatial case-control study, in which 'cases' were defined as individuals aged under 19 years of age with more severe asthma (defined here as two or more emergency department contacts with asthma in a defined 5-year period versus age- and gender-matched 'controls' with less severe asthma (defined here as one emergency department contact for asthma. Traffic exposures were measured using a GIS-based approach to determine the lengths of the roads falling within a buffer area, and then multiplying them by their respective traffic counts. Results We examined the spatial relationship between emergency department contacts for asthma at three different buffer sizes: 50 metres, 100 metres and 150 metres. No effect was noted for the 50 metre buffer (OR = 1.07; 95% CI: 0.91-1.26, but elevated odds ratios were observed with for crude (unadjusted estimates OR = 1.21 (95% CI: 1.00-1.46 for 100 metre buffers and OR = 1.25 (95% CI: 1.02-1.54 for 150 metre buffers. For adjusted risk estimates, only the 150 metre buffer yielded a statistically significant finding (OR = 1.24; 95% CI:1.00-1.52. Conclusions Our study revealed a significant 24% increase in the risk of experiencing multiple emergency department contacts for asthma for every log-unit of traffic exposure. This study provides support for the hypothesis that traffic related air pollution increases the frequency of health service contacts for asthma. This study used advanced GIS techniques to establish traffic-weighted buffer zones around the geocoded residential location of subjects to provide an accurate

A Case-Control Study of the Role of Human Papillomavirus in Oesophageal Squamous Cell Carcinoma in Australia

Directory of Open Access Journals (Sweden)

Surabhi S. Liyanage

2014-01-01

Full Text Available Objective. We investigate the prevalence of human papillomavirus (HPV in oesophageal squamous cell carcinoma (OSCC tissues compared to oesophageal tissue from healthy controls, in an Australian cohort. Methods. We conducted a hospital-based case-control study of 99 patients with OSCC and 100 healthy controls to examine the presence of HPV DNA. Paraffin tissues were tested using the PapType high-risk HPV detection and genotyping kit and with INNO-LiPA HPV Genotyping Extra. The biopsy samples were tested for HPV using a PCR-ELISA method based on the L1 consensus primer set PGMY09-PGMY11. Results. HPV DNA of the oncogenic genotype 16 was detected in 1/99 case specimens, a rate of 1010 per 100,000 (95% CI: 30–5500. All control specimens were negative for HPV. Significantly higher rates of smoking, other aerodigestive cancers, and mortality were seen among cases than controls. A pooled analysis of this study and the only other Australian case-control study found that 9/321 cases and 0/155 controls were positive for HPV. The pooled odds ratio for HPV being a risk factor for OSCC was 9.35 (95% CI: 0.47–190.33. Conclusion. Our results suggest that in this multifactorial cancer HPV may be an additional risk factor; although a larger, better powered study is needed.

Associated factors with attention deficit hyperactivity disorder (ADHD): a case-control study.

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Malek, Ayyoub; Amiri, Shahrokh; Sadegfard, Majid; Abdi, Salman; Amini, Saeedeh

2012-09-01

The current study attempted to investigate factors associated with attention deficit hyperactivity disorder (ADHD) in children without co-morbidities. In this case-control study, 164 ADHD children who attended the Child and Adolescent Psychiatric Clinics of Tabriz University of Medical Sciences, Iran were compared with 166 normal children selected in a random-cluster method from primary and secondary schools. Clinical interviews based on DSM-IV-TR using K-SADS were used to diagnose ADHD cases and to select the control group. Participants were matched for age. We used chi-square and binary logistic regression for data analysis. Among the associated factors with ADHD were gender and maternal employment. Boys (OR 0.54; 95% confidence interval: 0.34 - 0.86) and those children with working mothers (OR 0.16: 95% confidence interval: 0.06 - 0.86) suffered more from ADHD. The birth season, family size, birth order, and parental kinship were not among risk factors for ADHD. The results of the study show that maternal employment and male gender are among the associated risk factors for ADHD.

Investigation to identify a resource-efficient case-control methodology for determining antibiotics associated with Clostridium difficile infection.

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Chung, Philip; Currie, Brian; Guo, Yi; Talansky, Moshe; Brown, Shakara; Ostrowsky, Belinda

2014-10-01

Antimicrobial exposure remains an important risk factor for developing Clostridium difficile infection (CDI). Efficient method to identify antibiotics associated with CDI is important for formulating strategies to curtail their use. As a prelude to a more extensive Agency for Healthcare Research and Quality-funded project (Evaluation & Research on Antimicrobial Stewardship's Effect on Clostridium difficile), we undertook an exploratory evaluation to determine a resource-efficient method for identifying antibiotic targets for antimicrobial stewardship interventions. The study compared a series of 6 focused case-control studies. Cases consisted of patients with laboratory-confirmed CDI admitted from July-October 2009. Controls were selected from patients without CDI hospitalized during the same period. Five groups of controls were matched to cases (2:1 ratio) using group-specific matching criteria, including admission date, age, type of admission, length of stay (LOS) to discharge, and/or LOS to CDI diagnosis. The final control group was selected from patients who received antibiotics during hospitalization. Data, including demographics and antibiotic usage, were compared between case and control groups. A total of 126 cases were matched to 6 groups of 252 controls. For control groups 1-5, the use of piperacillin and tazobactam, ceftriaxone or cefepime, ciprofloxacin or moxifloxacin, intravenous vancomycin, azithromycin, and antibiotics of last resort were significantly more frequent in case than control patients. For the final control group, the associations between ceftriaxone or cefepime, and ciprofloxacin or moxifloxacin use and CDI no longer persisted. This could in part be explained by differences in comorbidities between case and control patients even with stringent matching criteria. Use of a simple matching strategy to conduct case-control studies is an efficient and feasible compromise strategy, especially in resource-limited settings, to identify high

Determinants of podoconiosis, a case control study | Feleke ...

African Journals Online (AJOL)

The sample size was calculated using Epi-info soft ware: 95% CI, 85% power, control to case ratio of 2:1, expected frequency of barefoot among controls 50%, odds ratio of 1.5 and non-response rate of 10% yielding 1148 study participants. Binary logistic regression was used to identify the determinants of Podoconiosis.

A case-control study of risk factors for epithelial ovarian cancer

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Ghaem Maghami Noori F

2001-09-01

Full Text Available Ovarian cancer is second prevalent cancer among gynecologic malignancies and the most common type of ovarian cancer is epithelial form (85-90 percent. To detect the risk factors for the epithelial ovarian cancer, a case-control study was conducted in Valieasr hospital in 1988. In this study, 118 cases with epithelial ovarian cancer (according histological records and 240 controls without any gynecological cancer in gynecologic clinic had been interviewed. For data analysis, T-test, Chi2 test and logistic regression have been used at a =0.05 as level of significance. The mean age in cases was 50±13 and in controls was 49.9±12 years, without significant different. The mean number of pregnancies and parity in cases was less than controls, significantly (P<0.03. The mean months of breast feeding in cases was less than controls (54.9±71.2 versus 82.4±62.7 (P<0.001. The cases had a lower mean age of menarch than controls (P=0.03. 58 percent of cases and 21.3 percent of controls hadn't used any contraception methods (P=0.00001. The mean years of contraception was significantly less in cases versus controls (P<0.001. The odds ratio for epithelial ovarian cancer was 0.24 (95 percent CI: 0.13-0.48 in OCP users, 0.47 (95 percent CI: 0.005-0.43 in TL method, and was 0.41 (95 percent CI: 0.22-0.76 in other contraception methods, relative to women who hadn't used any contraception methods. This study reveals that epithelial ovarian cancer risk increases significantly with earlier menarch, decreasing number of pregnancy, deliveries duration of breast feeding and use of contraception methods. Use of contraception pill and tubal ligation method decreases risk of epithelial ovarian cancer.

Risk factors for acute Toxoplasma gondii diseases in Taiwan: a population-based case-control study.

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Ting-Yi Chiang

Full Text Available Although human toxoplasmosis is a notifiable disease in Taiwan since 2007, little is known about its risk factors. This study aimed to investigate the risk factors for acute Toxoplasma gondii diseases in Taiwan. We conducted a nationwide population-based case-control study. Cases of acute human toxoplasmosis notified to the Taiwan Centers for Diseases Control (Taipei, Taiwan during 2008-2013 were compared with controls that were randomly selected from healthy T. gondii-seronegative blood donors who participated in a nationwide T. gondii seroepidemiologic study during 2009-2010. Cases and controls were matched according to age, gender and residency at an 1:8 ratio. Structured questionnaires were used to gather information regarding risk factors. A total of 30 laboratory-confirmed acute T. gondii disease cases and 224 controls were enrolled. The most common clinical manifestation of the cases was flu-like symptoms (n = 20, followed by central nervous system disease (n = 4, ocular diseases (n = 3, abortion (n = 2, and congenital infection (n = 1. Multivariate conditional logistic regression showed that raw clam consumption (adjusted odds ratio [OR] = 3.7; 95% confidence interval [CI] = 1.4-9.9 and having a cat in the household (adjusted OR = 2.9; 95% CI = 1.1-7.9 were two independent risk factors for acute T. gondii disease. We conclude that raw shellfish consumption and domestic cat exposure were risk factors for acquiring acute T. gondii diseases in Taiwan. This finding may guide future research and control policies.

Nitrates in municipal drinking water and non-Hodgkin lymphoma: an ecological cancer case-control study in Taiwan.

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Chang, Chih-Ching; Tsai, Shang-Shyue; Wu, Trong-Neng; Yang, Chun-Yuh

2010-01-01

The relationship between nitrate levels in drinking water and increased risk of non-Hodgkin lymphoma (NHL) development has been inconclusive. A matched cancer case-control and a nitrate ecology study was used to investigate the association between mortality attributed to NHL and nitrate exposure from Taiwan's drinking water. All deaths due to NHL in Taiwan residents from 2000 through 2006 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each case. Data on nitrate-nitrogen (NO(3)-N) levels of drinking water throughout Taiwan were collected from the Taiwan Water Supply Corporation (TWSC). The municipality of residence for cancer cases and controls was presumed to be the source of the subject's nitrate exposure via drinking water. The adjusted odds ratios (OR) for NHL death for those with high nitrate levels in their drinking water, as compared to the lowest tertile, were 1.02 (0.87-1.2) and 1.05 (0.89-1.24), respectively. The results of the present study show that there was no statistically significant association between nitrates in drinking water at levels in this investigation and increased risk of death attributed to NHL.

Pituitary tumor risk in relation to mobile phone use: A case-control study.

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Shrestha, Mithila; Raitanen, Jani; Salminen, Tiina; Lahkola, Anna; Auvinen, Anssi

2015-01-01

The number of mobile phone users has grown rapidly, which has generated mounting public concern regarding possible health hazards. This study aims to assess pituitary tumor risk, as it has rarely been investigated. A case-control study was conducted with 80 eligible cases identified from all five university hospitals in Finland and frequency-matched 240 controls from the national population register. Controls were matched to cases by age, sex, region of residence and date of interview. A detailed history of mobile phone use was obtained using a structured interview. Several indicators of mobile phone use were assessed using conditional logistic regression. A reduced odds ratio was seen among regular mobile phone users [OR 0.39, 95% confidence interval (CI) 0.21, 0.72] relative to never/non-regular users, possibly reflecting methodological limitations. Pituitary tumor risk was not increased after 10 or more years since first use (OR 0.69, 95% CI 0.25, 1.89). The risk was not increased in relation to duration, cumulative hours of use, or cumulative number of calls. The results were similar for analog and digital phones. We found no excess risk associated with self-reported short- or medium-term use of mobile phones. This is consistent with most of the published studies. However, uncertainties remained for longer duration of use, as a very small proportion of study participants reported use beyond 10 years.

Reducing selection bias in case-control studies from rare disease registries.

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Cole, J Alexander; Taylor, John S; Hangartner, Thomas N; Weinreb, Neal J; Mistry, Pramod K; Khan, Aneal

2011-09-12

In clinical research of rare diseases, where small patient numbers and disease heterogeneity limit study design options, registries are a valuable resource for demographic and outcome information. However, in contrast to prospective, randomized clinical trials, the observational design of registries is prone to introduce selection bias and negatively impact the validity of data analyses. The objective of the study was to demonstrate the utility of case-control matching and the risk-set method in order to control bias in data from a rare disease registry. Data from the International Collaborative Gaucher Group (ICGG) Gaucher Registry were used as an example. A case-control matching analysis using the risk-set method was conducted to identify two groups of patients with type 1 Gaucher disease in the ICGG Gaucher Registry: patients with avascular osteonecrosis (AVN) and those without AVN. The frequency distributions of gender, decade of birth, treatment status, and splenectomy status were presented for cases and controls before and after matching. Odds ratios (and 95% confidence intervals) were calculated for each variable before and after matching. The application of case-control matching methodology results in cohorts of cases (i.e., patients with AVN) and controls (i.e., patients without AVN) who have comparable distributions for four common parameters used in subject selection: gender, year of birth (age), treatment status, and splenectomy status. Matching resulted in odds ratios of approximately 1.00, indicating no bias. We demonstrated bias in case-control selection in subjects from a prototype rare disease registry and used case-control matching to minimize this bias. Therefore, this approach appears useful to study cohorts of heterogeneous patients in rare disease registries.

A prevalence-based association test for case-control studies.

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Ryckman, Kelli K; Jiang, Lan; Li, Chun; Bartlett, Jacquelaine; Haines, Jonathan L; Williams, Scott M

2008-11-01

Genetic association is often determined in case-control studies by the differential distribution of alleles or genotypes. Recent work has demonstrated that association can also be assessed by deviations from the expected distributions of alleles or genotypes. Specifically, multiple methods motivated by the principles of Hardy-Weinberg equilibrium (HWE) have been developed. However, these methods do not take into account many of the assumptions of HWE. Therefore, we have developed a prevalence-based association test (PRAT) as an alternative method for detecting association in case-control studies. This method, also motivated by the principles of HWE, uses an estimated population allele frequency to generate expected genotype frequencies instead of using the case and control frequencies separately. Our method often has greater power, under a wide variety of genetic models, to detect association than genotypic, allelic or Cochran-Armitage trend association tests. Therefore, we propose PRAT as a powerful alternative method of testing for association.

A case-control study on risk of changing food consumption for colorectal cancer.

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Zhang, Bing; Li, Xiangping; Nakama, Hidenori; Zhang, Xing; Wei, Ning; Zhang, Xiulan; Zhang, Leshan

2002-01-01

To investigate the relative risk factor of food items for colorectal cancer in four time periods through a case-control study in a Chinese rural area. Colorectal cancer patients diagnosed at a county cancer center, Hebei Province, China, and non-cancer outpatients with similar age, sex, and place of residence were selected for cases and controls, respectively. There were 102 (93.6%) colorectal cancer patients and 99 (90.8%) outpatients being the cases and controls, respectively in the present investigation, who agreed to be interviewed about their food intake, during a 20-year period, through a food frequency questionnaire. The risks of intake of different food items and lifestyle for colorectal cancer were compared between cases and controls. During the 20-year period, diets of both cases and controls changed with increase in intake of animal foods and fruits, and alcohol consumption tended to increase. In the food items, milk intake showed a protective effect in both males and females, and the odds ratios were 0.38 (95% CI 0.16-0.90) and 0.28 (95% CI 0.10-0.81) for males and females, respectively. A reduced risk of fruit intake could be seen in males, while a reduced risk of vegetables could be observed in females. Meat intake and saturated fats were the prominent risk factors for colorectal cancer in males and females, respectively. A comparison of life habits, showed that tea drinking had a consistent protective effect in females, and the odds ratios were 0.21 (0.08-0.58), 0.23 (0.08-0.67), 0.25 (0.10-0.64), and 0.11 (0.04-0.30) for periods of 20-, 10-, 5-years ago, and current time, respectively. These findings indicate that change in food consumption is strongly associated with a change in risk of colorectal cancer, and dietary meat has increased the risk of colorectal cancer. Increase in the consumption of milk and fruits may be a significant measure for colorectal cancer prevention in low-incidence areas.

Pesticide exposure and lymphohaematopoietic cancers: a case-control study in an agricultural region (Larissa, Thessaly, Greece).

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Kokouva, Maria; Bitsolas, Nikolaos; Hadjigeorgiou, Georgios M; Rachiotis, George; Papadoulis, Nikolaos; Hadjichristodoulou, Christos

2011-01-04

The causality of lymphohaematopoietic cancers (LHC) is multifactorial and studies investigating the association between chemical exposure and LHC have produced variable results. The aim of this study was to investigate the relationships between exposure to pesticides and LHC in an agricultural region of Greece. A structured questionnaire was employed in a hospital-based case control study to gather information on demographics, occupation, exposure to pesticides, agricultural practices, family and medical history and smoking. To control for confounders, backward conditional and multinomial logistic regression analyses were used. To assess the dose-response relationship between exposure and disease, the chi-square test for trend was used. Three hundred and fifty-four (354) histologically confirmed LHC cases diagnosed from 2004 to 2006 and 455 sex- and age-matched controls were included in the study. Pesticide exposure was associated with total LHC cases (OR 1.46, 95% CI 1.05-2.04), myelodysplastic syndrome (MDS) (OR 1.87, 95% CI 1.00-3.51) and leukaemia (OR 2.14, 95% CI 1.09-4.20). A dose-response pattern was observed for total LHC cases (P = 0.004), MDS (P = 0.024) and leukaemia (P = 0.002). Pesticide exposure was independently associated with total LHC cases (OR 1.41, 95% CI 1.00 - 2.00) and leukaemia (OR 2.05, 95% CI 1.02-4.12) after controlling for age, smoking and family history (cancers, LHC and immunological disorders). Smoking during application of pesticides was strongly associated with total LHC cases (OR 3.29, 95% CI 1.81-5.98), MDS (OR 3.67, 95% CI 1.18-12.11), leukaemia (OR 10.15, 95% CI 2.15-65.69) and lymphoma (OR 2.72, 95% CI 1.02-8.00). This association was even stronger for total LHC cases (OR 18.18, 95% CI 2.38-381.17) when eating simultaneously with pesticide application. Lymphohaematopoietic cancers were associated with pesticide exposure after controlling for confounders. Smoking and eating during pesticide application were identified as

Serum Taurine and Stroke Risk in Women: A Prospective, Nested Case-Control Study

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Wu, Fen; Koenig, Karen L.; Zeleniuch-Jacquotte, Anne; Jonas, Saran; Afanasyeva, Yelena; Wójcik, Oktawia P.; Costa, Max; Chen, Yu

2016-01-01

Background Taurine (2-aminoethanesulfonic acid), a conditionally essential sulfur-containing amino acid, is mainly obtained from diet in humans. Experimental studies have shown that taurine’s main biological actions include bile salt conjugation, blood pressure regulation, anti-oxidation, and anti-inflammation. Methods We conducted a prospective case-control study nested in the New York University Women’s Health Study, a cohort study involving 14,274 women enrolled since 1985. Taurine was measured in pre-diagnostic serum samples of 241 stroke cases and 479 matched controls. Results There was no statistically significant association between serum taurine and stroke risk in the overall study population. The adjusted ORs for stroke were 1.0 (reference), 0.87 (95% CI, 0.59–1.28), and 1.03 (95% CI, 0.69–1.54) in increasing tertiles of taurine (64.3–126.6, 126.7–152.9, and 153.0–308.5 nmol/mL, respectively). A significant inverse association between serum taurine and stroke risk was observed among never smokers, with an adjusted OR of 0.66 (95% CI, 0.37–1.18) and 0.50 (95% CI, 0.26–0.94) for the second and third tertile, respectively (p for trend = 0.01), but not among past or current smokers (p for interaction taurine and stroke risk, although a protective effect was observed in never smokers, which requires further investigation. Taurine, Stroke, Epidemiology, Prospective, Case-control study, NYUWHS. PMID:26866594

The relationship between maternal periodontitis and preterm low birth weight: A case-control study

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Satheesh Mannem

2011-01-01

Full Text Available Background: The relationship between periodontal diseases in pregnancy and children born prematurely or with low birth weight has been increasingly investigated, showing positive and negative results, respectively. Objective: To evaluate the association between Maternal Periodontitis and Preterm delivery or Low Birth Weight. Materials and Methods: In this case-control study, 104 pregnant women without systemic disease or other risk factors for preterm labor were chosen. The control group (n = 52 had term labor (infants ≥37 weeks and the case group (n = 52 had preterm labor (infants <37 weeks. Plaque index, bleeding index, and birth weight were measured. Results: The data of plaque index (cases 1.21±0.56; controls 0.63±0.31, bleeding index (cases, 2.08±0.62; controls, 1.52±0.61, birth weight (cases, 2.01±0.36; controls 2.87±0.32, and Probing Pocket Depth (PPD ≥4mm and Clinical Attachment Level (CAL ≥3mm in at least 4 teeth (odds ratio 137.50, P value < 0.0001 revealed a statistically significant difference between the two groups P< 0.05. Conclusions: A noticeable relationship between periodontal health and duration of pregnancy; periodontal disease could be a risk factor for preterm labor. Oral hygiene maintenance should be a part of prenatal care protocol.

Organizing pneumonia and occupational and environmental risk factors: a case-control study.

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Jobard, Stéphanie; Chaigne, Benjamin; Marchand-Adam, Sylvain; Lasfargues, Gérard; Diot, Elisabeth

2017-11-01

A single-center case-control study was carried out to investigate the relationship between occupational and environmental exposure and organizing pneumonia (OP). Thirty-seven cases of OP, including 25 cases of cryptogenic OP, and 111 controls were included. Occupational exposure was assessed retrospectively by an industrial hygienist and an occupational physician, through semi-quantitative estimates of exposure. An exposure score was calculated for each subject, based on probability, intensity, daily frequency, and duration of exposure for each period of employment. The final cumulative exposure score was obtained by summing exposure scores for all periods of employment. Significant associations with all-cause OP were observed for exposure to tetrachloroethylene (OR 13.33, CI 95% 1.44-123.5) and silica (OR 6.61, CI 95% 1.16-37.71). A significant association with cryptogenic OP was observed only for tetrachloroethylene (OR 31.6, CI 95% 1.64-610.8). No associations were found for environmental exposure. Despite its low statistical power, this work suggests that occupational risk factors could be involved in OP.

Studies of CTNNBL1 and FDFT1 variants and measures of obesity: analyses of quantitative traits and case-control studies in 18,014 Danes

DEFF Research Database (Denmark)

Andreasen, Camilla Helene; Mogensen, Mette Sloth; Borch-Johnsen, Knut

2009-01-01

of obesity-related quantitative traits, and case-control studies in large study samples of Danes. METHODS: The FDFT1 rs7001819, CTNNBL1 rs6013029 and rs6020846 were genotyped, using TaqMan allelic discrimination, in a combined study sample comprising 18,014 participants ascertained from; the population...... and a previous study. FDFT1 rs7001819 showed no association with obesity, neither when analysing quantitative traits nor when performing case-control studies of obesity.......). The most significantly associating variants within CTNNBL1 including rs6013029 and rs6020846 were additionally confirmed to associate with morbid obesity in a French Caucasian case-control sample. The aim of this study was to investigate the impact of these three variants on obesity, through analyses...

Neurocognitive performance in family-based and case-control studies of schizophrenia

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Gur, Ruben C.; Braff, David L.; Calkins, Monica E.; Dobie, Dorcas J.; Freedman, Robert; Green, Michael F.; Greenwood, Tiffany A.; Lazzeroni, Laura C.; Light, Gregory A.; Nuechterlein, Keith H.; Olincy, Ann; Radant, Allen D.; Seidman, Larry J.; Siever, Larry J.; Silverman, Jeremy M.; Sprock, Joyce; Stone, William S.; Sugar, Catherine A.; Swerdlow, Neal R.; Tsuang, Debby W.; Tsuang, Ming T.; Turetsky, Bruce I.; Gur, Raquel E.

2014-01-01

Background Neurocognitive deficits in schizophrenia (SZ) are established and the Consortium on the Genetics of Schizophrenia (COGS) investigated such measures as endophenotypes in family-based (COGS-1) and case-control (COGS-2) studies. By requiring family participation, family-based sampling may result in samples that vary demographically and perform better on neurocognitive measures. Methods The Penn computerized neurocognitive battery (CNB) evaluates accuracy and speed of performance for several domains and was administered across sites in COGS-1 and COGS-2. Most tests were included in both studies. COGS-1 included 328 patients with SZ and 497 healthy comparison subjects (HCS) and COGS-2 included 1195 patients and 1009 HCS. Results Demographically, COGS-1 participants were younger, more educated, with more educated parents and higher estimated IQ compared to COGS-2 participants. After controlling for demographics, the two samples produced very similar performance profiles compared to their respective controls. As expected, performance was better and with smaller effect sizes compared to controls in COGS-1 relative to COGS-2. Better performance was most pronounced for spatial processing while emotion identification had large effect sizes for both accuracy and speed in both samples. Performance was positively correlated with functioning and negatively with negative and positive symptoms in both samples, but correlations were attenuated in COGS-2, especially with positive symptoms. Conclusions Patients ascertained through family-based design have more favorable demographics and better performance on some neurocognitive domains. Thus, studies that use case-control ascertainment may tap into populations with more severe forms of illness that are exposed to less favorable factors compared to those ascertained with family-based designs. PMID:25432636

Neurocognitive performance in family-based and case-control studies of schizophrenia.

Science.gov (United States)

Gur, Ruben C; Braff, David L; Calkins, Monica E; Dobie, Dorcas J; Freedman, Robert; Green, Michael F; Greenwood, Tiffany A; Lazzeroni, Laura C; Light, Gregory A; Nuechterlein, Keith H; Olincy, Ann; Radant, Allen D; Seidman, Larry J; Siever, Larry J; Silverman, Jeremy M; Sprock, Joyce; Stone, William S; Sugar, Catherine A; Swerdlow, Neal R; Tsuang, Debby W; Tsuang, Ming T; Turetsky, Bruce I; Gur, Raquel E

2015-04-01

Neurocognitive deficits in schizophrenia (SZ) are established and the Consortium on the Genetics of Schizophrenia (COGS) investigated such measures as endophenotypes in family-based (COGS-1) and case-control (COGS-2) studies. By requiring family participation, family-based sampling may result in samples that vary demographically and perform better on neurocognitive measures. The Penn computerized neurocognitive battery (CNB) evaluates accuracy and speed of performance for several domains and was administered across sites in COGS-1 and COGS-2. Most tests were included in both studies. COGS-1 included 328 patients with SZ and 497 healthy comparison subjects (HCS) and COGS-2 included 1195 patients and 1009 HCS. Demographically, COGS-1 participants were younger, more educated, with more educated parents and higher estimated IQ compared to COGS-2 participants. After controlling for demographics, the two samples produced very similar performance profiles compared to their respective controls. As expected, performance was better and with smaller effect sizes compared to controls in COGS-1 relative to COGS-2. Better performance was most pronounced for spatial processing while emotion identification had large effect sizes for both accuracy and speed in both samples. Performance was positively correlated with functioning and negatively with negative and positive symptoms in both samples, but correlations were attenuated in COGS-2, especially with positive symptoms. Patients ascertained through family-based design have more favorable demographics and better performance on some neurocognitive domains. Thus, studies that use case-control ascertainment may tap into populations with more severe forms of illness that are exposed to less favorable factors compared to those ascertained with family-based designs.

Haplotype-based case-control study between human apurinic/apyrimidinic endonuclease 1/redox effector factor-1 gene and cerebral infarction.

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Naganuma, Takahiro; Nakayama, Tomohiro; Sato, Naoyuki; Fu, Zhenyan; Yamaguchi, Mai; Soma, Masayoshi; Aoi, Noriko; Usami, Ron; Doba, Nobutaka; Hinohara, Shigeaki

2009-10-01

The aim of this study was to investigate the relationship between cerebral infarction (CI) and the human apurinic/apyrimidinic endonuclease 1/redox effector factor-1 (APE1/REF-1) gene using single-nucleotide polymorphisms (SNPs) and a haplotype-based case-control study. We selected 5 SNPs in the human APE1/REF1 gene (rs1760944, rs3136814, rs17111967, rs3136817 and rs1130409), and performed case-control studies in 177 CI patients and 309 control subjects. rs17111967 was found to have no heterogeneity in Japanese. The overall distribution of the haplotype-based case-control study constructed by rs1760944, rs3136814 and rs1130409 showed a significant difference. The frequency of the G-C-T haplotype was significantly higher in the CI group than in the control group (2.5% vs. 0.0%, p>0.001). Based on the results of the haplotype-based case-control-study, the G-C-T haplotype may be a genetic marker of CI, and the APE1/REF-1 gene may be a CI susceptibility gene.

Intrapartum electrocardiogram alteration in fetuses with congenital heart disease: a case-control study.

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Gay, Estelle; Bornallet, Géraldine; Gaucherand, Pascal; Doret, Muriel

2015-11-01

To assess if the fetal electrocardiogram especially ST segment is modified by congenital heart diseases: modifications in frequencies of the different ST events and modifications in signal quality. A retrospective case-control study, comparing frequencies of the different ST events and the quality of the signal between fetuses with congenital heart diseases and fetuses without congenital heart disease. From 2000 to 2011, fifty-eight fetuses with congenital heart disease had their heart rate recording using a STAN device during labor. Control group was fetuses who were born just before a case and had a STAN as a second line for intrapartum surveillance. Cases and controls were matched on parity, gestational age at birth, presence of growth restriction and umbilical artery pH. Frequencies of the different ST event and quality of the signal were first analyzed for the global labor recording, and then separately for the first and the second phase of labor. No statistically significant difference in ST event frequencies between fetuses with congenital heart disease and the control group was found. Regarding the quality of the signal, 11.49% (±18.82) of recording time is a signal loss for fetus with congenital heart disease whereas only 5.18% (±10.67) for the control group (p=0.028). This is the first study investigating for intrapartum electrocardiogram modification in fetus with congenital heart disease. Congenital heart diseases do not modify frequencies of ST events. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Laryngeal sarcoidosis: a case-control study.

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Duchemann, Boris; Lavolé, Armelle; Naccache, Jean-Marc; Nunes, Hilario; Benzakin, Sylvain; Lefevre, Marine; Kambouchner, Marianne; Périé, Sophie; Valeyre, Dominique; Cadranel, Jacques

2014-10-20

We undertook a study on a series of laryngeal sarcoidosis (LS), a very rare and often threatening localization to better specify laryngeal manifestations, sarcoidosis clinical expression and long-term follow-up. This was a retrospective case-control study. All LS patients from two French centers were included and compared to sarcoidosis patients without laryngeal localization with two controls for one patient. Twelve consecutive LS patients were recruited between 1993 and 2011. LS revealed sarcoidosis in eight cases (67%). The most common symptoms were hoarseness (77%), inspiratory dyspnea (38%) and dysphagia (38%). Epidemiological characterisics were not different. Extrapulmonary localizations were significantly more common in LS patients than in controls (92% vs. 54%, p=0.02), particularly lupus pernio (25% vs. 0%, p=0.03) and nasosinusal involvement (83% vs. 4%, p<0.01) while thoracic involvement was less frequent (58% vs 100%, p < 0.01). Treatment rates were higher in the LS group (92% vs. 58%, p=0.04), and treatment duration was longer (median: 81 vs. 13 months, p=0.04), with frequent long-term treatment (67%, N=8/12). Two patients underwent surgery. One patient needed temporary tracheostomy during the course of the disease; Remission rates were lower in LS patients (9% vs. 58% at 2 years p<0.01). Eventually, there was no death nor definitive tracheotomy. LS is a rare condition that is often associated to other loco-regional localizations. LS are often difficult to manage. Survival is good but may require a medico-surgical approach.

Case-control study of gadodiamide-related nephrogenic systemic fibrosis

DEFF Research Database (Denmark)

Marckmann, Peter; Skov, Lone; Rossen, Kristian

2007-01-01

exposed to gadodiamide develop nephrogenic systemic fibrosis. METHODS: We conducted a case-control study of 19 histologically verified cases and 19 sex- and age-matched controls. All subjects had chronic renal failure when exposed to gadodiamide. Clinical, biochemical and pharmacological data were.......02). CONCLUSIONS: Increasing cumulative gadodiamide exposure, high-dose epoietin-beta treatment, and higher serum concentrations of ionized calcium and phosphate increase the risk of gadodiamide-related nephrogenic systemic fibrosis in renal failure patients. Severe cases seem to develop primarily among patients......BACKGROUND: Nephrogenic systemic fibrosis may be caused by gadolinium (Gd)-containing magnetic resonance imaging contrast agents. Most reported cases were associated with one particular agent, gadodiamide. Yet, unidentified cofactors might explain why only a minority of renal failure patients...

Reducing selection bias in case-control studies from rare disease registries

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Mistry Pramod K

2011-09-01

Full Text Available Abstract Background In clinical research of rare diseases, where small patient numbers and disease heterogeneity limit study design options, registries are a valuable resource for demographic and outcome information. However, in contrast to prospective, randomized clinical trials, the observational design of registries is prone to introduce selection bias and negatively impact the validity of data analyses. The objective of the study was to demonstrate the utility of case-control matching and the risk-set method in order to control bias in data from a rare disease registry. Data from the International Collaborative Gaucher Group (ICGG Gaucher Registry were used as an example. Methods A case-control matching analysis using the risk-set method was conducted to identify two groups of patients with type 1 Gaucher disease in the ICGG Gaucher Registry: patients with avascular osteonecrosis (AVN and those without AVN. The frequency distributions of gender, decade of birth, treatment status, and splenectomy status were presented for cases and controls before and after matching. Odds ratios (and 95% confidence intervals were calculated for each variable before and after matching. Results The application of case-control matching methodology results in cohorts of cases (i.e., patients with AVN and controls (i.e., patients without AVN who have comparable distributions for four common parameters used in subject selection: gender, year of birth (age, treatment status, and splenectomy status. Matching resulted in odds ratios of approximately 1.00, indicating no bias. Conclusions We demonstrated bias in case-control selection in subjects from a prototype rare disease registry and used case-control matching to minimize this bias. Therefore, this approach appears useful to study cohorts of heterogeneous patients in rare disease registries.

Low maternal folate concentrations and maternal MTHFR C677T polymorphism are associated with an increased risk for neural tube defects in offspring: a case-control study among Pakistani case and control mothers.

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Nauman, Nuzhat; Jalali, Samina; Shami, Sajjad; Rafiq, Shireen; Große, Greta; Hilger, Alina C; Zhang, Rhong; Mansoor, Saira; Ludwig, Michael; Reutter, Heiko

2018-01-01

There is considerable evidence that periconceptional maternal folate deficiency and coding variants in maternal genes coding for critical enzymes in the folate pathway are associated with neural tube defects (NTDs) in offspring. In a case-control study we investigated C677T polymorphism in the 5,10- methylenetetrahydrofolate reductase (MTHFR) gene in case and control mothers of Pakistani origin, and compared these with the respective maternal folate concentrations measured at the time of delivery. A case-control study was conducted among 109 case and 100 control mothers identified through the Holy Family Hospital Rawalpindi, Quaid-i-Azam University, Islamabad, Pakistan. Red blood cell (RBC) and serum folate concentrations and MTHFRC677T polymorphism were compared between case and control mothers. Mean RBC folate and serum folate concentrations were significantly lower in cases compared with control mothers (pcases compared with control mothers (CC vs TT pcases compared with control mothers (C vs T pCase mothers with 677CT or 677TT genotypes had significantly lower serum (pstudy provides further evidence that maternal folate deficiency and MTHFRC677T polymorphism might be associated with an increased risk for NTDs in offspring. Our results are limited by the fact that maternal folate concentrations were not obtained during the periconceptional period, but at delivery. Further analyses, including maternal folate levels during the periconceptional period, are warranted.

Suspected survivor bias in case-control studies: stratify on survival time and use a negative control.

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van Rein, Nienke; Cannegieter, Suzanne C; Rosendaal, Frits R; Reitsma, Pieter H; Lijfering, Willem M

2014-02-01

Selection bias in case-control studies occurs when control selection is inappropriate. However, selection bias due to improper case sampling is less well recognized. We describe how to recognize survivor bias (i.e., selection on exposed cases) and illustrate this with an example study. A case-control study was used to analyze the effect of statins on major bleedings during treatment with vitamin K antagonists. A total of 110 patients who experienced such bleedings were included 18-1,018 days after the bleeding complication and matched to 220 controls. A protective association of major bleeding for exposure to statins (odds ratio [OR]: 0.56; 95% confidence interval: 0.29-1.08) was found, which did not become stronger after adjustment for confounding factors. These observations lead us to suspect survivor bias. To identify this bias, results were stratified on time between bleeding event and inclusion, and repeated for a negative control (an exposure not related to survival): blood group non-O. The ORs for exposure to statins increased gradually to 1.37 with shorter time between outcome and inclusion, whereas ORs for the negative control remained constant, confirming our hypothesis. We recommend the presented method to check for overoptimistic results, that is, survivor bias in case-control studies. Copyright © 2014 Elsevier Inc. All rights reserved.

Dietary intake of folate and riboflavin, MTHFR C677T Genotype, and colorectal adenoma risk: a Dutch case-control study

NARCIS (Netherlands)

Donk, van den M.; Buijsse, G.M.; Berg, van den S.W.; Ocké, M.C.; Harryvan, J.L.; Nagengast, F.M.; Kok, F.J.; Kampman, E.

2005-01-01

We investigated the associations between dietary intake of folate and vitamin B2, MTHFR C677T genotype, and colorectal adenomas in a Dutch case-control study. Data of cases with at least one histologically confirmed colorectal adenoma (n = 768) and controls with no history of any type of colorectal

Intrapartum amnioinfusion in meconium-stained liquor: a case-control study.

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Bansal, Neeta; Gupta, Vineeta; Nanda, Anuja; Chaudhary, Priyanka; Tandon, Archna; Behl, Neelima

2013-06-01

The aim of this study was to investigate perinatal outcome and the rate of cesarean section (CS) following intrapartum amnioinfusion in women with meconium-stained amniotic fluid (MSAF). A total of 100 women at term in labor with meconium were randomized to infuse transcervical intrapartum amnioinfusion with saline (50) and routine obstetrical care (50). Perinatal outcome and obstetric outcome were recorded and analyzed in both groups by means of Chi-square test. The CS rate due to fetal distress was 40.0 % in the control group and 20.0 % in the study group. The difference was statistically significant (P Amnioinfusion in cases of meconium-stained liquor significantly improved neonatal outcome and CS rate without increasing any maternal and fetal complications.

Retrospective exposure assessment and quality control in an international multi-centre case-control study

DEFF Research Database (Denmark)

Tinnerberg, H; Heikkilä, P; Huici-Montagud, A

2003-01-01

The paper presents the exposure assessment method and quality control procedure used in an international, multi-centre case-control study within a joint Nordic and Italian cohort. This study was conducted to evaluate whether occupational exposure to carcinogens influenced the predictivity of high...... was higher among the original assessors (the assessor from the same country as the subject) than the average prevalence assessed by the other four in the quality control round. The original assessors classified more job situations as exposed than the others. Several reasons for this are plausible: real...... country-specific differences, differences in information available to the home assessor and the others and misunderstandings or difficulties in translation of information. To ensure the consistency of exposure assessments in international retrospective case-control studies it is important to have a well...

Psychiatric comorbidity may not predict suicide during and after hospitalization. A nested case-control study with blinded raters.

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Walby, Fredrik A; Odegaard, Erik; Mehlum, Lars

2006-06-01

To investigate the differential impact of DSM-IV axis-I and axis-II disorders on completed suicide and to study if psychiatric comorbidity increases the risk of suicide in currently and previously hospitalized psychiatric patients. A nested case-control design based on case notes from 136 suicides and 166 matched controls. All cases and controls were rediagnosed using the SCID-CV for axis-I and the DSM-IV criteria for axis-II disorders and the inter-rater reliability was satisfactory. Raters were blind to the case and control status and the original hospital diagnoses. Depressive disorders and bipolar disorders were associated with an increased risk of suicide. No such effect was found for comorbidity between axis-I disorders and for comorbidity between axis-I and axis-II disorders. Psychiatric diagnoses, although made using a structured and criteria-based approach, was based on information recorded in case notes. Axis-II comorbidity could only be investigated at an aggregated level. Psychiatric comorbidity did not predict suicide in this sample. Mood disorders did, however, increase the risk significantly independent of history of previous suicide attempts. Both findings can inform identification and treatment of patients at high risk for completed suicide.

Risk Factors Profile of Shoulder Dystocia in Oman: A Case Control Study

OpenAIRE

Maha M. Al-Khaduri; Rania Mohammed Abudraz; Sayed G. Rizvi; Yahya M. Al-Farsi

2014-01-01

Objective: This study aimed to assess the risk factor profile of shoulder dystocia and associated neonatal complications in Oman, a developing Arab country. Methods: A retrospective case-control study was conducted among 111 cases with dystocia and 111 controls, identified during 1994-2006 period in a tertiary care hospital in Oman. Controls were randomly selected among women who did not have dystocia, and were matched to cases on the day of delivery. Data related to potential risk factor...

Determinants of impaired growth among hospitalized children: a case-control study

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Marilia de Carvalho Lima

Full Text Available CONTEXT: Protein energy malnutrition constitutes a public health problem, especially in less affluent countries. The identification of amenable predictive risk factors is of major importance for policy makers to plan interventions to reduce infant malnutrition. OBJECTIVE: To identify risk factors for protein energy malnutrition among hospitalized low-income children aged 6 to 24 months. TYPE OF STUDY: Case-control study. SETTING: Two public hospitals in Recife, Brazil. PARTICIPANTS: The cases were 124 infants with length-for-age below the 10th percentile of the National Center for Health Statistics curve and the controls were 241 infants with length-for-age equal to or above the 10th percentile who were recruited in the same infirmary. METHODS: Cases and controls were compared in relation to a variety of sociodemographic, environmental and reproductive factors, and their healthcare, previous feeding practice and morbidity. Logistic regression analysis was used to investigate the net effect of risk factors on infant malnutrition, after adjusting for potential confounding variables. RESULTS: The mother's age, possession of a TV set, type of water supply, family size and location of the home were significantly associated with child malnutrition in the bivariate analysis. However, these associations lost their significance after adjusting for other explanatory variables in the hierarchical logistic regression analysis. This analysis showed that low birth weight contributed the largest risk for impaired growth. Increased risks of infant malnutrition were also significantly associated with households that had no toilet facilities or refrigerator, high parity for the mother, no breastfeeding of the infant, inadequate vaccination coverage and previous hospitalization for diarrhea and pneumonia. DISCUSSION: The literature shows that chronic malnutrition, as assessed by low length-for-age indexes, is often related to low income. However, this was not the

Case-control study of fetal microchimerism and breast cancer.

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Vijayakrishna K Gadi

2008-03-01

Full Text Available Prior pregnancy is known to protect against development of breast cancer. Recent studies have demonstrated that pregnancy has the capacity to establish small numbers of immunologically active fetal-derived cells in the mother, a phenomenon known as fetal microchimerism (FMc. We asked whether presence of FMc, routinely acquired during pregnancy, is a protective factor for breast cancer.DNA extracts from peripheral blood specimens were obtained from a population-based case-control study of risk factors for breast cancer in women 21 to 45 years old. Specimens were tested with quantitative PCR for presence and concentrations of male DNA presumed to derive from prior pregnancies with a male fetus. Odds ratios (OR and 95% confidence intervals (CI were estimated with consideration of multiple established reproductive and environmental risk factors for breast cancer. FMc results were generated on 99 parous women, 54 with primary invasive breast cancer and 45 general population controls. FMc prevalence was 56% (25/45 and 26% (14/54 in controls and cases, respectively. Women harboring FMc were less likely to have had breast cancer (OR = 0.29, 95% CI 0.11-0.83; p = 0.02, adjusting for age, number of children, birth of a son, history of miscarriage, and total DNA tested. In addition, FMc concentrations were higher in controls versus cases (p = 0.01. Median concentrations were 2 (0-78 and 0 (0-374 fetal genomes/10(6 maternal genomes in controls and cases, respectively.Results suggest that the enigma of why some parous women are not afforded protection from breast cancer by pregnancy might in part be explained by differences in FMc. Mechanistic studies of FMc-derived protection against breast cancer are warranted.

Forensic Polygraph in Crime Investigation: A Case Study

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Aabad Ayoub

2016-06-01

Full Text Available A polygraph is an instrument that measures and records physiological changes inside the body. In the absence of a valid physical evidence, polygraphy may be a useful technique to verify truthfulness or detect deception. The present study was conducted to determine the truthfulness of a suspect in a murder case that was referred to PFSA for a polygraph examination. The stomach contents of the examinee and the hyoid bone of the vicvtim were submitted to the department of toxicology and forensic pathology at the PFSA, respectively. In the present study, integrated zone comparison technique (IZCT and forensic assessment interview technique (FAINT designed for specific and multi issue testing were used to examine the suspect. Computerized Academy for Scientific Investigative training (ASIT Algorithm and weighted scoring were applied in IZCT and FAINT scoring, respectively. The suspect of this murder case was brought to PFSA for polygraph examination. During the initial interview, the suspect denied any involvement in the said case. However, after complete polygraph examination, the suspect was proven to have been deceptive and later on confessed to police officials. The polygraph examination of the suspect proved him deceptive which was later confirmed by his confession. His stomach did not contain any toxic/ sedative material.

A case-control study on risk factors of breast cancer in Han Chinese women.

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Liu, Li-Yuan; Wang, Fei; Cui, Shu-De; Tian, Fu-Guo; Fan, Zhi-Min; Geng, Cui-Zhi; Cao, Xu-Chen; Yang, Zhen-Lin; Wang, Xiang; Liang, Hong; Wang, Shu; Jiang, Hong-Chuan; Duan, Xue-Ning; Wang, Hai-Bo; Li, Guo-Lou; Wang, Qi-Tang; Zhang, Jian-Guo; Jin, Feng; Tang, Jin-Hai; Li, Liang; Zhu, Shi-Guang; Zuo, Wen-Shu; Yu, Li-Xiang; Xiang, Yu-Juan; Zhou, Fei; Li, Liang; Zhang, Qiang; Fu, Qin-Ye; Ma, Zhong-Bing; Gao, De-Zong; Li, Yu-Yang; Liu, Lu; Ye, Chun-Miao; Wang, Yong-Jiu; Zhou, Wen-Zhong; Yu, Zhi-Gang

2017-11-14

This study aimed to investigate risk factors associated with breast cancer among Han Chinese women in northern and eastern China. A matched case-control study involving 1489 patients with breast cancer and 1489 controls was conducted across 21 hospitals in 11 provinces in China, from April 2012 to April 2013. We developed a structured questionnaire to record information from face-to-face interviews with participants. Student's t-tests, Pearson's chi-square tests, and univariate and multivariate conditional logistic regression analyses were used to identify variables with significant differences between the case and control groups. Ten variables were identified (P ratio, menopause, family history of breast cancer, present life satisfaction, sleep satisfaction, milk products, behavior prevention scores, and awareness of breast cancer. We identified a comprehensive range of factors related to breast cancer, among which several manageable factors may contribute to breast cancer prevention. Further prospective studies concerning psychological interventions, sleep regulation, health guidance, and physical exercise are required. A screening model for high-risk populations should be put on the agenda.

Association between group A beta-haemolytic streptococci and vulvovaginitis in adult women: a case-control study.

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Bruins, M J; Damoiseaux, R A M J; Ruijs, G J H M

2009-08-01

Guidelines for the management of vaginal discharge mention Candida albicans, Trichomonas vaginalis, bacterial vaginosis, Chlamydia trachomatis and Neisseria gonorrhoeae as causes and do not recommend full microbiological culture. The role of non-group B beta-haemolytic streptococci in vaginal cultures is unclear, except for group A streptococci that are known to cause vulvovaginitis in children. In a case-control study, we investigated the association between non-group B beta-haemolytic streptococci and vulvovaginitis in adult women. Cases were women with recurrent vaginal discharge from whom a sample was cultured. Controls were asymptomatic women who consented to submitting a vaginal swab. Group A streptococci were isolated from 49 (4.9%) of 1,010 cases and not from the 206 controls (P < 0.01). Isolation rates of group C, F and G streptococci were low and did not differ statistically between cases and controls. Group A beta-haemolytic streptococci are associated with vaginal discharge in adult women. The other non-group B streptococci require more study. For the adequate management of vaginal discharge, culturing is necessary if initial treatment fails. Guidelines should be amended according to these results.

Dengue infection and miscarriage: a prospective case control study.

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Peng Chiong Tan

Full Text Available BACKGROUND: Dengue is the most prevalent mosquito borne infection worldwide. Vertical transmissions after maternal dengue infection to the fetus and pregnancy losses in relation to dengue illness have been reported. The relationship of dengue to miscarriage is not known. METHOD: We aimed to establish the relationship of recent dengue infection and miscarriage. Women who presented with miscarriage (up to 22 weeks gestation to our hospital were approached to participate in the study. For each case of miscarriage, we recruited 3 controls with viable pregnancies at a similar gestation. A brief questionnaire on recent febrile illness and prior dengue infection was answered. Blood was drawn from participants, processed and the frozen serum was stored. Stored sera were thawed and then tested in batches with dengue specific IgM capture ELISA, dengue non-structural protein 1 (NS1 antigen and dengue specific IgG ELISA tests. Controls remained in the analysis if their pregnancies continued beyond 22 weeks gestation. Tests were run on 116 case and 341 control sera. One case (a misdiagnosed viable early pregnancy plus 45 controls (39 lost to follow up and six subsequent late miscarriages were excluded from analysis. FINDINGS: Dengue specific IgM or dengue NS1 antigen (indicating recent dengue infection was positive in 6/115 (5·2% cases and 5/296 (1·7% controls RR 3·1 (95% CI 1·0-10 P = 0·047. Maternal age, gestational age, parity and ethnicity were dissimilar between cases and controls. After adjustments for these factors, recent dengue infection remained significantly more frequently detected in cases than controls (AOR 4·2 95% CI 1·2-14 P = 0·023. INTERPRETATION: Recent dengue infections were more frequently detected in women presenting with miscarriage than in controls whose pregnancies were viable. After adjustments for confounders, the positive association remained.

Appendectomy and Risk of Subsequent Diverticular Disease Requiring Hospitalization: A Population-Based Case-Control Study.

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Sköldberg, Filip; Olén, Ola; Ekbom, Anders; Schmidt, Peter T

2018-07-01

Appendicitis and acute diverticulitis share clinical features and are both influenced by genetic and environmental factors. Appendectomy has been positively associated with diverticular disease in hospital-based case-control studies. The aim of the present study was to investigate, in a population-based setting, whether appendectomy, with or without appendicitis, is associated with an altered risk of hospitalization with diverticular disease. This was a population-based case-control study. The study was based on national healthcare and population registers. We studied 41,988 individuals hospitalized between 2000 and 2010 with a first-time diagnosis of colonic diverticular disease and 413,115 matched control subjects. The association between appendectomy with or without appendicitis and diverticular disease was investigated by conditional logistic regression, including a model adjusting for hospital use. A total of 2813 cases (6.7%) and 19,037 controls (4.6%) had a previous record of appendectomy (appendectomy with acute appendicitis: adjusted OR = 1.31 (95% CI, 1.24-1.39); without appendicitis: adjusted OR = 1.30 (95% CI, 1.23-1.38)). Appendectomy was most strongly associated with an increased risk of diverticular disease within 1 year (with appendicitis: adjusted OR = 2.26 (95% CI, 1.61-3.16); without appendicitis: adjusted OR = 3.98 (95% CI, 2.71-5.83)), but the association was still present ≥20 years after appendectomy (with appendicitis: adjusted OR = 1.22 (95% CI, 1.12-1.32); without appendicitis: adjusted OR = 1.19 (95% CI, 1.10-1.28)). Detailed clinical information on the cases was not available. There were unmeasured potential confounders, such as smoking and dietary factors. The findings are consistent with a hypothesis of appendectomy causing an increased risk of diverticular disease, for example, by affecting the mucosal immune system or the gut microbiome. However, several other mechanisms may contribute to, or account for, the positive association

The Relationship between Chronic Constipation and Urinary Tract Infection in Children: A Case-Control Clinical Study

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Gholamreza Sarvari

2017-09-01

Full Text Available Background Urinary tract infection (UTI is one of the most common bacterial infections in children, if not diagnosed leads to serious complications such as hypertension, chronic renal failure and renal scar. Constipation is one of the main risk factors for recurrent UTI. The aim of present study was to investigate the relationship between chronic constipation and urinary tract infection in children. Materials and Methods In this case-control study 105 patients with functional chronic constipation as case group, compared with 104 children without chronic constipation as control. The control group was matched according to gender and age. The prevalence of UTI in children with and without constipation as well as their improvement was compared after treatment. Results The prevalence of UTI in case and control groups was 13.3% and 6.7%, respectively (P=0.17. The prevalence of UTI in case group decreased to 3.8% after treatment of constipation. Escherichia coli (E coli was the most commonly isolated organism in both groups. Conclusion Results of present study showed that despite of no significant urinary tract infection incidence between children with constipation and those without constipation, the constipation should still be considered as a predisposing risk factor for the UTI occurrence.

HPV and cofactors for invasive cervical cancer in Morocco: a multicentre case-control study.

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Berraho, Mohamed; Amarti-Riffi, Afaf; El-Mzibri, Mohammed; Bezad, Rachid; Benjaafar, Noureddine; Benideer, Abdelatif; Matar, Noureddine; Qmichou, Zinab; Abda, Naima; Attaleb, Mohammed; Znati, Kaoutar; El Fatemi, Hind; Bendahhou, Karima; Obtel, Majdouline; Filali Adib, Abdelhai; Mathoulin-Pelissier, Simone; Nejjari, Chakib

2017-06-20

Limited national information is available in Morocco on the prevalence and distribution of HPV-sub-types of cervical cancer and the role of other risk factors. The aim was to determine the frequency of HPV-sub-types of cervical cancer in Morocco and investigate risk factors for this disease. Between November 2009 and April 2012 a multicentre case-control study was carried out. A total of 144 cases of cervical cancer and 288 age-matched controls were included. Odds-ratios and corresponding confidence-intervals were computed by conditional logistic regression models. Current HPV infection was detected in 92.5% of cases and 13.9% of controls. HPV16 was the most common type for both cases and controls. Very strong associations between HPV-sub-types and cervical cancer were observed: total-HPV (OR = 39), HPV16 (OR = 49), HPV18 (OR = 31), and multiple infections (OR = 13). Education, high parity, sexual intercourse during menstruation, history of sexually transmitted infections, and husband's multiple sexual partners were also significantly associated with cervical cancer in the multivariate analysis. Our results could be used to establish a primary prevention program and to prioritize limited screening to women who have specific characteristics that may put them at an increased risk of cervical cancer.

Oestrogen receptor α gene haplotype and postmenopausal breast cancer risk: a case control study

International Nuclear Information System (INIS)

Wedrén, Sara; Stiger, Fredrik; Persson, Ingemar; Baron, John; Weiderpass, Elisabete; Lovmar, Lovisa; Humphreys, Keith; Magnusson, Cecilia; Melhus, Håkan; Syvänen, Ann-Christine; Kindmark, Andreas; Landegren, Ulf; Fermér, Maria Lagerström

2004-01-01

Oestrogen receptor α, which mediates the effect of oestrogen in target tissues, is genetically polymorphic. Because breast cancer development is dependent on oestrogenic influence, we have investigated whether polymorphisms in the oestrogen receptor α gene (ESR1) are associated with breast cancer risk. We genotyped breast cancer cases and age-matched population controls for one microsatellite marker and four single-nucleotide polymorphisms (SNPs) in ESR1. The numbers of genotyped cases and controls for each marker were as follows: TA n , 1514 cases and 1514 controls; c.454-397C → T, 1557 cases and 1512 controls; c.454-351A → G, 1556 cases and 1512 controls; c.729C → T, 1562 cases and 1513 controls; c.975C → G, 1562 cases and 1513 controls. Using logistic regression models, we calculated odds ratios (ORs) and 95% confidence intervals (CIs). Haplotype effects were estimated in an exploratory analysis, using expectation-maximisation algorithms for case-control study data. There were no compelling associations between single polymorphic loci and breast cancer risk. In haplotype analyses, a common haplotype of the c.454-351A → G or c.454-397C → T and c.975C → G SNPs appeared to be associated with an increased risk for ductal breast cancer: one copy of the c.454-351A → G and c.975C → G haplotype entailed an OR of 1.19 (95% CI 1.06–1.33) and two copies with an OR of 1.42 (95% CI 1.15–1.77), compared with no copies, under a model of multiplicative penetrance. The association with the c.454-397C → T and c.975C → G haplotypes was similar. Our data indicated that these haplotypes were more influential in women with a high body mass index. Adjustment for multiple comparisons rendered the associations statistically non-significant. We found suggestions of an association between common haplotypes in ESR1 and the risk for ductal breast cancer that is stronger in heavy women

[Lack of association between MMR vaccination and the incidence of autism in children: a case-control study].

Science.gov (United States)

Mrozek-Budzyn, Dorota; Kiełtyka, Agnieszka; Majewska, Renata

2009-01-01

The matched case-control study has been undertook to investigate whether measles, mumps, and rubella (MMR) vaccine may be casually associated with autism in children. Cases were children to 14-year old with diagnosis of core autism or atypical autism. Controls were matched on age, sex and general practice. The 96 cases and 192 controls were included. The study provides strong evidence against association of autism with both MMR and a single measles individual vaccine. Additionally children vaccinated with MMR, regardless of age of vaccination (to 18th, 24th and 36th month of life), had risk equal half of that of single measles vaccinated (for vaccinated to 18th month OR=0.41 95%PU: 0.20-0.85). Our findings confirm that MMR vaccination is not associated with an increased risk of autism in children.

Leukaemia incidence among workers in the shoe and boot manufacturing industry: a case-control study

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Forand Steven P

2004-08-01

Full Text Available Abstract Background Previous reports have indicated an excess of leukaemia in Broome County, New York, particularly in the Town of Union. Surveillance of cancer incidence data indicates that a large proportion of these cases occurred among males ages 65 and older. Shoe and boot manufacturing has been the largest single industry in this area throughout much of the past century. Occupational studies from Europe suggest a link between leukaemia and employment in the shoe and boot manufacturing industry. However, researchers have not found a positive association between leukaemia and employment in the shoe industry among workers in the United States. Methods A matched case-control study was conducted to investigate the association between leukaemia incidence among males 65 and older and employment in the shoe and boot manufacturing industry. Thirty-six cases of leukaemia occurring between 1981–1990; among males age 65 and older; residing in the town of Union met the study case criteria. Death certificates were obtained for each of the cases. These were matched to death certificates of 144 controls on date of death and date of birth +/- 1 year. Death certificates were then examined to determine the employer and occupation of each study subject. Conditional logistic regression was used to determine the risk of leukaemia among those working in the industry. Results The risk of both leukaemia (OR = 1.47; 95% CI 0.70, 3.09 and acute myeloid leukaemia (OR = 1.19; 95% CI 0.33, 4.28 were elevated among those employed in the shoe and boot manufacturing industry, however neither was statistically significant. Conclusion The results, though suggestive of an association between leukaemia and employment in the shoe and boot manufacturing industry, were not statistically conclusive due mainly to limited study power. Several additional limitations may also have prevented the observance of more conclusive findings. Better exposure assessment, information on

Analgesics use and ESRD in younger age: a case-control study

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Moehner Sabine

2007-12-01

Full Text Available Abstract Background An ad hoc peer-review committee was jointly appointed by Drug Authorities and Industry in Germany, Austria and Switzerland in 1999/2000 to review the evidence for a causal relation between phenacetin-free analgesics and nephropathy. The committee found the evidence as inconclusive and requested a new case-control study of adequate design. Methods We performed a population-based case-control study with incident cases of end-stage renal disease (ESRD under the age of 50 years and four age and sex-matched neighborhood controls in 170 dialysis centers (153 in Germany, and 17 in Austria from January 1, 2001 to December 31, 2004. Data on lifetime medical history, risk factors, treatment, job exposure and intake of analgesics were obtained in a standardized face-to-face interview using memory aids to enhance accuracy. Study design, study performance, analysis plan, and study report were approved by an independent international advisory committee and by the Drug Authorities involved. Unconditional logistic regression analyses were performed. Results The analysis included 907 cases and 3,622 controls who had never used phenacetin-containing analgesics in their lifetime. The use of high cumulative lifetime dose (3rd tertile of analgesics in the period up to five years before dialysis was not associated with later ESRD. Adjusted odds ratios with 95% confidence intervals were 0.8 (0.7 – 1.0 and 1.0 (0.8 – 1.3 for ever- compared with no or low use and high use compared with low use, respectively. The same results were found for all analgesics and for mono-, and combination preparations with and without caffeine. No increased risk was shown in analyses stratifying for dose and duration. Dose-response analyses showed that analgesic use was not associated with an increased risk for ESRD up to 3.5 kg cumulative lifetime dose (98 % of the cases with ESRD. While the large subgroup of users with a lifetime dose up to 0.5 kg (278 cases and

Obstacles to action in arthritis: a community case-control study.

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Hutton, Ingrid; Gamble, Greg; McLean, Grant; Butcher, Hugh; Gow, Peter; Dalbeth, Nicola

2009-07-01

Despite the benefits of physical activity, people with arthritis are less active than the general population. The aim of this study was to determine the motivators and obstacles to physical activity for adults with arthritis. Participants were identified from the Obstacles to Action Study, a community based study of 8163 adults, which explored barriers and motivators to physical activity. A 1:1 case-control study was designed; cases were identified as those participants who reported arthritis (n = 1106). Each case was matched with an age, sex and ethnicity-matched non-arthritis control (n = 1106). Cases were less likely to achieve recommended physical activity targets (58.8% vs. 68.1% P = 0.00001). Furthermore, fewer people with arthritis believed that physical activity would help them lead healthy lives (86.7% vs. 91.3% P = 0.006) or viewed physical activity as a priority (53.8% vs. 59.8% P = 0.005). Cases were less confident in their abilities to try a new activity (37.1% vs. 43.7% P = 0.002) or maintain a healthy weight (65.0% vs. 74.3% P = 0.00001). Cases also reported greater negative impact scores for barriers to activity, particularly arthritis, accessibility, cost and discomfort while exercising. Motivators and environmental barriers to activity were similar for cases and controls. These findings persisted after adjusting for educational level, body mass index and comorbidities. People with arthritis are less active and demonstrate different attitudes toward physical activity. Although people with arthritis identify similar environmental barriers, they have different psychosocial barriers. In order to design effective physical activity programs for people with arthritis, these barriers must be specifically addressed.

Periodontal disease and spontaneous preterm birth: a case control study

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Eley Barry

2006-07-01

Full Text Available Abstract Background Several studies have suggested an association between periodontal disease and prematurity but this finding has not been consistently observed. Methods Case control study. Cases (n = 50 were women who had delivered after spontaneous preterm labor at Results There was no difference in the proportion of sites with significant attachment loss (≥3 mm: Cases-3.2%, Controls-2.2% p = 0.21. The gingival crevicular fluid concentrations of elastase and gingipain were elevated in cases vs. controls 238.8 uU/ul vs. 159.6 uU/ul p = .007 and 2.70 uU/ul vs. 1.56 uU/ul p = .001. On multivariate analysis, the mean log concentration of elastase, but not of gingipain, remained a significant predictor of preterm labor p = .0.015. Conclusion We found no evidence that clinical periodontal disease is associated with spontaneous preterm birth. Elevated gingival crevicular fluid levels of elastase were associated with preterm birth but further research is needed before this can be assumed to be a causal relationship.

Fragrance allergy and quality of life - a case-control study.

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Heisterberg, Maria V; Menné, Torkil; Johansen, Jeanne D

2014-02-01

Fragrance ingredients can cause contact allergy, which may affect quality of life (QoL). However, few studies have investigated this topic. To investigate QoL life among subjects with a fragrance allergy as compared with other eczema patients. A case-control survey was sent to subjects with a positive patch test reaction to a fragrance ingredient/marker (n = 550) and to a control group (n = 1100). It contained questions on eczema and the newly developed fragrance QoL index. Participants had been consecutively patch tested at Gentofte University Hospital (2000-2010). The response rate was 65.7%. Information on patch test data was retrieved from the National Contact Dermatitis Database. An increase in impairment of QoL was observed in women with fragrance allergy as compared with the control group (p = 0.042), which was not found among men. Several factors played a significant role in impairment of QoL in women: (i) number of fragrance allergies, (ii) severity of the patch test reaction, (iii) age combined with recent diagnosis; and (iv) allergy to specific fragrance ingredients/markers. Fragrance-allergic subjects are just as affected in their QoL as other eczema patients. However, women, and in particular recently diagnosed young women, seem to be more impaired in their QoL than other eczema patients. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Selection of population controls for a Salmonella case-control study in the UK using a market research panel and web-survey provides time and resource savings.

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Mook, P; Kanagarajah, S; Maguire, H; Adak, G K; Dabrera, G; Waldram, A; Freeman, R; Charlett, A; Oliver, I

2016-04-01

Timely recruitment of population controls in infectious disease outbreak investigations is challenging. We evaluated the timeliness and cost of using a market research panel as a sampling frame for recruiting controls in a case-control study during an outbreak of Salmonella Mikawasima in the UK in 2013. We deployed a web-survey by email to targeted members of a market research panel (panel controls) in parallel to the outbreak control team interviewing randomly selected public health staff by telephone and completing paper-based questionnaires (staff controls). Recruitment and completion of exposure history web-surveys for panel controls (n = 123) took 14 h compared to 15 days for staff controls (n = 82). The average staff-time cost per questionnaire for staff controls was £13·13 compared to an invoiced cost of £3·60 per panel control. Differences in the distribution of some exposures existed between these control groups but case-control studies using each group found that illness was associated with consumption of chicken outside of the home and chicken from local butchers. Recruiting market research panel controls offers time and resource savings. More rapid investigations would enable more prompt implementation of control measures. We recommend that this method of recruiting controls is considered in future investigations and assessed further to better understand strengths and limitations.

Nutritional risk assessment for Hip fracture, A Case control study

OpenAIRE

Torbergsen, Anne Cathrine

2016-01-01

The study was conducted at Oslo University Hospital, Norway. Patients were included from September 2009 until April 2011. In total 116 patients and 73 healthy non-fractured controls participated. The study has 3 parts. In the first part, we studied micronutrients and the risk of hip fracture in a case control study. In the second part, we conducted a randomized controlled nutrition intervention trial and finally, in the third part, we studied if micronutrients were associated with delirium in...

Association of HCV with diabetes mellitus: an Egyptian case-control study

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Esmat Gamal G

2011-07-01

Full Text Available Abstract Background The highest Hepatitis C Virus (HCV prevalence in the world occurs in Egypt. Several studies from different parts of the world have found that 13% to 33% of patients with chronic HCV have associated diabetes, mostly type II Diabetes Mellitus (DM. In Egypt the prevalence of DM is 25.4% among HCV patients. Therefore, it is important to identify the magnitude of the problem of diabetes in order to optimize the treatment of chronic hepatitis C. Methods The objective of this case-control study was to evaluate the prevalence of DM and other extrahepatic (EH manifestations among patients with different HCV morbidity stages including asymptomatic, chronic hepatic and cirrhotic patients. In this study, 289 HCV patients older than 18 were selected as cases. Also, 289 healthy controls were included. Laboratory investigations including Liver Function tests (LFT and blood glucose level were done. Also serological assays including cryoglobulin profile, rheumatoid factor, antinuclear antibody, HCV-PCR were performed. Results Out of 289 HCV cases, 40 (13.84% were diabetic. Out of 289 healthy controls, 12 (4.15% were diabetic. It was found that the diabetic HCV group mean age was [48.1 (± 9.2]. Males and urbanians represented 72.5% and 85% respectively. Lower level of education was manifested in 52.5% and 87.5% were married. In the nondiabetic HCV group mean age was [40.7 (± 10.4]. Males and urbanians represented 71.5% and 655% respectively. secondary and higher level of education was attained in 55.4% and 76.7% were married. Comparing between the diabetic HCV group and the non diabetic HCV group, age, residence and alcohol drinking were the only significant factors affecting the incidence of diabetes between the two groups. There was no significant difference regarding sonar findings although cirrhosis was more prevalent among diabetic HCV cases and the fibrosis score was higher in diabetic HCV patients than among the non diabetic HCV cases

Risk Factors For Ectopic Pregnancy : A Case Control Study

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Deshmukh J.S

1999-01-01

Full Text Available Research question: Which are the risk factors for ectopic pregnancy . Objective: To study the strength of association between hypothesised risk factors and ectopic pregnancy. Study design: Unmatched case- control study. Setting: Government Medical College, Hospital, Nagpur. Participants: 133 cases of ectopic pregnancy and equal number of controls (non pregnant women admitted to study hospital. Study variables : Pelvic inflammatory diseases, sexually transmitted diseases, IUD use at conception , past use of IUD, prior ectopic pregnancy, OC pills use at the time of conception, past use of OC pills, induced abortion, spontaneous abortion, infertility and pelvic and abdominal surgery. Statistical analysis: Odds ratios & their 95% CI, Pearson’s chi square test, unconditional logistic regression analysis and population attributable risk proportion. Results : Use of IUD at conception, prior ectopic pregnancy , pelvic inflammatory disease, sexually transmitted diseases, infertility, OC pills use at the time of conception, past use of IUD and induced abortion were found to be significantly associated with ectopic pregnancy. Conclusion: Identification of these risk factors for etopic pregnancy shall help in early detection and appropriate management in an individual case and it may help in devising a comprehensive preventive strategy for ectopic pregnancy

Estimating time-varying exposure-outcome associations using case-control data: logistic and case-cohort analyses.

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Keogh, Ruth H; Mangtani, Punam; Rodrigues, Laura; Nguipdop Djomo, Patrick

2016-01-05

Traditional analyses of standard case-control studies using logistic regression do not allow estimation of time-varying associations between exposures and the outcome. We present two approaches which allow this. The motivation is a study of vaccine efficacy as a function of time since vaccination. Our first approach is to estimate time-varying exposure-outcome associations by fitting a series of logistic regressions within successive time periods, reusing controls across periods. Our second approach treats the case-control sample as a case-cohort study, with the controls forming the subcohort. In the case-cohort analysis, controls contribute information at all times they are at risk. Extensions allow left truncation, frequency matching and, using the case-cohort analysis, time-varying exposures. Simulations are used to investigate the methods. The simulation results show that both methods give correct estimates of time-varying effects of exposures using standard case-control data. Using the logistic approach there are efficiency gains by reusing controls over time and care should be taken over the definition of controls within time periods. However, using the case-cohort analysis there is no ambiguity over the definition of controls. The performance of the two analyses is very similar when controls are used most efficiently under the logistic approach. Using our methods, case-control studies can be used to estimate time-varying exposure-outcome associations where they may not previously have been considered. The case-cohort analysis has several advantages, including that it allows estimation of time-varying associations as a continuous function of time, while the logistic regression approach is restricted to assuming a step function form for the time-varying association.

Attention deficit hyperactivity disorder in children with primary monosymptomatic nocturnal enuresis: A case-control study

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Parsa Yousefichaijan

2016-01-01

Full Text Available Attention deficit hyperactivity disorder (ADHD is one of the most common childhood neurological disorders. The aim of this study was to investigate ADHD in children with primary monosymptomatic nocturnal enuresis (PMNE and compare it with healthy children. A total of 100 five to 16-year-old children with PMNE and 100 healthy children without NE were included in this case-control study as the cases and control groups, respectively. Subjects were selected from children who were referred to the pediatric clinic of the Amir Kabir Hospital of Arak, Iran, based on inclusion and exclusion criteria. ADHD was diagnosed by Conner′s Parent Rating Scale-48 and the Diagnostic and Statistical Manual of Mental Disorders, fourth edition criteria and was confirmed by consultation with a psychiatrist. Data were analyzed by binomial test using SPSS18. ADHD inattentive type was observed in 16 cases (16% with PMNE and five controls (5% (P = 0.01. Despite these significant differences in the case and control groups, 25 (25% and 16 (16% children were affected by ADHD hyperactive-impulsive type (P = 0.08 and 15 (15% and 16 (16% children were affected by ADHD mixed type (P = 0.84, respectively. ADHD inattentive type in children with PMNE was significantly more common than that in healthy children. The observed correlation between ADHD inattentive type and PMNE makes psychological counseling mandatory in children with PMNE.

Response rates in case-control studies of cancer by era of fieldwork and by characteristics of study design.

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Xu, Mengting; Richardson, Lesley; Campbell, Sally; Pintos, Javier; Siemiatycki, Jack

2018-04-09

The purpose of this study was to describe time trends in response rates in case-control studies of cancer and identify study design factors that influence response rate. We reviewed 370 case-control studies of cancer published in 12 journals during indicator years in each of the last four decades. We estimated time trends of response rates and reasons for nonresponse in each of the following types of study subjects: cases, medical source controls, and population controls. We also estimated response rates according to characteristics of study context. Median response rates among cases and population controls were between 75% and 80% in the 1970s. Between 1971 and 2010, study response rates declined by 0.31% per year for cases and 0.78% for population controls. Only a minority of studies reported reasons for nonparticipation; subject refusal was the most common reported reason. Studies conducted in North America had lower median response rates than studies conducted in Europe. In-person and telephone interviews elicited higher response rates than mail questionnaires. Response rates from case-control studies of cancer have declined, and this could threaten the validity of results derived from these studies. Copyright © 2018 Elsevier Inc. All rights reserved.

Violence against Women and Gastroschisis: A Case-Control Study

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Daniel Ruiz

2013-10-01

Full Text Available Background: Gastroschisis, a birth defect characterized by herniated fetal abdominal wall, occurs more commonly in infants born to teenage and young mothers. Ischemia of the vascular vitelline vessels is the likely mechanism of pathogenesis. Given that chronic stress and violence against women are risk factors for cardiovascular disease we explored whether these may represent risk factors for gastroschisis, when they occur during pregnancy. A case-control study was conducted, with 15 incident cases of children born with gastroschisis in the Region of Murcia, Spain, from December 2007 to June 2013. Forty concurrent controls were recruited at gestation weeks 20–24 or post-partum. All mothers of cases and controls completed a comprehensive, in-person, ‘green sheet’ questionnaire on environmental exposures. Results: Mothers of children with gastroschisis were younger, smoked more cigarettes per week relative to controls, were exposed to higher amounts of illegal drugs, and suffered from domestic violence more frequently than the controls. Multivariable logistic regression analysis highlights periconceptional ‘gender-related violence’ (OR: 16.6, 95% CI 2.7 to 101.7 and younger maternal age (OR 1.1, 95% CI 1.0–1.3. Conclusions: Violence against pregnant women is associated with birth defects, and should be studied in more depth as a cause-effect teratogenic. Psychosocial risk factors, including gender-based violence, are important for insuring the health and safety of the pregnant mother and the fetus.

Sample size calculations for case-control studies

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This R package can be used to calculate the required samples size for unconditional multivariate analyses of unmatched case-control studies. The sample sizes are for a scalar exposure effect, such as binary, ordinal or continuous exposures. The sample sizes can also be computed for scalar interaction effects. The analyses account for the effects of potential confounder variables that are also included in the multivariate logistic model.

Drug and alcohol crash risk : a case-control study.

Science.gov (United States)

2016-12-01

This study used a case-control design to estimate the risk of crashes involving drivers using drugs, alcohol or both. Data was collected in Virginia Beach, Virginia, for 20 months. The study obtained biological measures on more than 3,000 crash...

Risk factors for posterior vitreous detachment: a case-control study.

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Chuo, Jean Y; Lee, Tracy Y Y; Hollands, Hussein; Morris, Andrew H; Reyes, Romina C; Rossiter, Jonathan D; Meredith, Sarah P; Maberley, David A L

2006-12-01

To identify possible risk factors for the development of posterior vitreous detachment (PVD). Retrospective case-control study. A total of 138 cases with PVD and 114 age-matched controls were accrued from two different sites. Demographic, medical, ocular, and lifestyle data were obtained through chart review, questionnaires, and clinical examination. A 108-item semiquantitative food frequency questionnaire was also used to estimate macro- and micronutrient intake. Univariate and multivariate regression analyses were employed to identify variables significantly associated with the main outcome measure of PVD. Subgroup analysis of gender-specific variables was performed. Among all patients, multivariate regression analysis demonstrated female gender (odds ratio [OR] = 2.01, P = .016), myopic refraction (OR = 4.32, P < .0005), and higher intake of vitamin B6 (OR = 2.61, P = .001) to be associated with PVD after controlling for age. In the subgroup analysis of women, menopause (OR = 18.2, P < .0005), myopic refraction (OR = 3.42, P = .01), and higher intake of vitamin B6 (OR = 3.92, P = .005) were associated with PVD. Specifically, there was a significant association between vitamin B6 and PVD amongst premenopausal women but not amongst postmenopausal women. An association between PVD and menopause has not been documented previously. We suspect that high estrogen levels seen in premenopausal women may be protective against PVD and that hormonal changes associated with menopause may lead to changes in the vitreous, predisposing to PVD. Higher levels of intake of vitamin B6 were also associated with the development of PVD in premenopausal women possibly through an anti-estrogen effect. These findings should be investigated further with prospective studies.

Sympathetic skin response in multiple sclerosis: a meta-analysis of case-control studies.

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Margaritella, Nicolò; Mendozzi, Laura; Garegnani, Massimo; Gilardi, Elisabetta; Nemni, Raffaello; Pugnetti, Luigi

2018-01-01

The usefulness of sympathetic skin responses (SSR) in multiple sclerosis (MS) has been advocated by several studies in the last 20 years; however, due to a great heterogeneity of findings, a comprehensive meta-analysis of case-control studies is in order to pinpoint consistencies and investigate the causes of discrepancies. We searched MEDLINE, EMBASE and Cochrane databases for case-control studies comparing SSR absence frequency and latency between patients with MS and healthy controls. Thirteen eligible studies including 415 MS patients and 331 healthy controls were identified. The pooled analysis showed that SSR can be always obtained in healthy controls while 34% of patients had absent SSRs in at least one limb (95% CI 22-47%; p studies (I 2  = 90.3%). Patients' age explained 22% of the overall variability and positive correlations were found with Expanded Disability Status Scale and disease duration. The pooled mean difference of SSR latency showed a significant increase in patients on both upper (193 ms; 95% CI 120-270 ms) and lower (350 ms; 95% CI 190-510 ms) extremities. We tested the discriminatory value of SSR latency thresholds defined as the 95% confidence interval (CI) upper bound of the healthy controls, and validated the results on a new dataset. The lower limb threshold of 1.964 s produces the best results in terms of sensitivity 0.86, specificity 0.67, positive predicted value 0.75 and negative predicted value 0.80. Despite a considerable heterogeneity of findings, there is evidence that SSR is a useful tool in MS.

Role of nutrition in pre-eclampsia and eclampsia cases, a case control study

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Punyatoya Bej

2014-12-01

Full Text Available Background: Preeclampsia and eclampsia during pregnancy contribute to maternal and fetal morbidity as well as mortality. The identification of the role of maternal nutrition during pregnancy will help in reducing morbidity and mortality. Aims & Objective: The objective of this study is to find out the role of nutrition, in the form of total calorie, protein, fruits, iron, folic acid and calcium intake in the development of preeclampsia and eclampsia among pregnant women in a tertiary level hospital. Material Methods: After ethical approval and informed consent, 122 women who delivered beyond 22 weeks of gestation and diagnosed as preeclampsia or eclampsia were selected. Simultaneously, 122 controls with no diagnosis of preeclampsia or eclampsia were selected from the post natal ward. Cases and controls were administered the same pre-tested questionnaire containing questions related to food and micronutrient intake by cases and control. Results: Logistic regression was applied in the statistical analysis. The factors that were found to be significant predictors of risk for development of preeclampsia and eclampsia were higher calorie intake (adjusted Odds Ratio (OR 14.12 [6.41-43.23] P < 0.001, less protein intake (adjusted OR 3.87 [1.97-8.01] P < 0.001 during pregnancy. Fruits intake in both cases and controls were similar. 77.9% of cases and 84.4% of controls had taken iron tablets during their antenatal period. 75.4% of cases and 82.8% of controls had taken calcium tablets during their antenatal period. Iron and calcium intake is not significantly associated with development of preeclampsia and eclampsia. Conclusion: Higher calorie intake and less protein intake during pregnancy were associated with development of preeclampsia and eclampsia. Fruits intake, iron and calcium intake were not associated with development of preeclampsia and eclampsia

Risk factors for gallbladder cancer: a case-control study.

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Jain, Kajal; Sreenivas, V; Velpandian, T; Kapil, Umesh; Garg, Pramod Kumar

2013-04-01

Risk factors for gallbladder cancer (GBC) except gallstones are not well known. The objective was to study the risk factors for GBC. In a case-control study, 200 patients with GBC, 200 healthy controls and 200 gallstones patients as diseased controls were included prospectively. The risk factors studied were related to socioeconomic profile, life style, reproduction, diet and bile acids. On comparing GBC patients (mean age 51.7 years; 130 females) with healthy controls, risk factors were chemical exposure [odd ratios (OR): 7.0 (2.7-18.2); p < 0.001)], family history of gallstones [OR: 5.3 (1.5-18.9); p < 0.01)], tobacco [OR: 4.1 (1.8-9.7); p < 0.001)], fried foods [OR: 3.1 (1.7-5.6); p < 0.001], joint family [OR: 3.2 (1.7-6.2); p < 0.001], long interval between meals [OR: 1.4 (1.2-1.6); p < 0.001] and residence in Gangetic belt [OR: 3.3 (1.8-6.2); p < 0.001]. On comparing GBC cases with gallstone controls, risk factors were female gender [OR: 2.4 (1.3-4.3); p = 0.004], residence in Gangetic belt [OR: 2.3 (1.2-4.4); p = 0.012], fried foods [OR: 2.5 (1.4-4.4); p < 0.001], diabetes [OR: 2.7 (1.2-6.4); p = 0.02)], tobacco [OR 3.8 (1.7-8.1); p < 0.001)] and joint family [OR: 2.1 (1.2-3.4); p = 0.004]. The ratio of secondary to primary bile acids was significantly higher in GBC cases than gallstone controls (20.8 vs. 0.44). Fried foods, tobacco, chemical exposure, family history of gallstones, residence in Gangetic belt and secondary bile acids were significant risk factors for GBC. Copyright © 2012 UICC.

A case-control study of risk factors for male infertility in Southern ...

African Journals Online (AJOL)

Aim: The purpose of this study was to evaluate the association between selected potential socio-demographic and behavioural risk factors and infertility in Nigeria males. Methods: The study consisted of cases and controls. The cases were 150 males with proven male infertility, while the controls were 150 fertile males with ...

Investigating sexual problems, psychological distress and quality of life in female patients with Takotsubo cardiomyopathy: A prospective case-control study.

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Saffari, Mohsen; Lin, Chung-Ying; Broström, Anders; Mårtensson, Jan; Malm, Dan; Burri, Andrea; Fridlund, Bengt; Pakpour, Amir H

2017-10-01

Takotsubo cardiomyopathy (TSCM) has detrimental effects on both physical and psychological health of sufferers. However, little is known whether TSCM also affects sexual functioning in female patients. The aim of this study was to investigate psychological distress (depression and anxiety), health-related quality of life, and sexual functioning in women with TSCM and compare them with women with acute myocardial infarction and with healthy controls. A three group prospective case-control design was used. Female patients with TSCM or acute myocardial infarction, as well as healthy controls (94 in each group), were recruited across eight Iranian university hospitals. Data were collected at baseline and after six and 18 months using the Hospital Anxiety and Depression Scale, the Short Form-12, the Female Sexual Function Index and the Female Sexual Distress Scale. Multilevel logistic regression was conducted. The TSCM group showed worst sexual functioning and the highest level of anxiety and depression at baseline ( pquality of life at baseline, which was lower in both groups compared with the healthy controls ( pquality of life showed a significant change over time, especially in the TSCM group, with health-related quality of life decreasing, while anxiety and depression were increasing. Compared with the acute myocardial infarction and healthy control groups, the TSCM group showed a higher prevalence of sexual problems (odds ratios = 3.10 and 2.28, respectively) across time. Moreover, sexual functioning was found to be a mediator between anxiety and health-related quality of life in the TSCM group. Depression, anxiety, health-related quality of life, and sexual dysfunction tend to increase over time in female patients with TSCM; thus, healthcare providers should pay attention to these problems and provide appropriate treatment where necessary.

A case study on the investigation of reasoning skills in geometry ...

African Journals Online (AJOL)

The aim of this study is to evaluate the reasoning skills in geometry-related subjects of six 8th Grade students. The study data were obtained at the end of the 2011-2012 spring period in a public elementary school. The study uses a case study with qualitative research techniques to investigate how students use reasoning ...

Screening detected celiac disease in children with type 1 diabetes mellitus : Effect on the clinical course - (A case control study)

NARCIS (Netherlands)

Rami, B; Sumnik, Z; Schober, E; Waldhor, T; Battelino, T; Bratanic, N; Kurti, K; Lebl, J; Limbert, C; Madacsy, L; Odink, RJH; Paskova, M; Soltesz, G

Objective: To investigate clinical and metabolic characteristics of diabetic children with screening detected celiac disease in a multicenter case-control study. Methods: Cases: 98 diabetic patients were diagnosed as having silent celiac disease by screening with endomysial antibodies and subsequent

Residential radon exposure and lung cancer risk in Misasa, Japan. A case-control study

International Nuclear Information System (INIS)

Sobue, Tomotaka; Lee, Valerie S.; Ye, Weimin; Tanooka, Hiroshi; Mifune, Masaaki; Suyama, Akihiko; Koga, Taeko; Morishima, Hiroshige; Kondo, Sohei

2000-01-01

In order to investigate an association between residential radon exposure and risk of lung cancer, a case-control study was conducted in Misasa Town, Tottori Prefecture, Japan. The case series consisted of 28 people who had died of lung cancer in the years 1976-96 and 36 controls chosen randomly from the residents in 1976, matched by sex and year of birth. Individual residential radon concentrations were measured for 1 year with alpha track detectors. The average radon concentration was 46 Bq/m 3 for cases and 51 Bq/m 3 for controls. Compared to the level of 24 or less Bq/m 3 , the adjusted odds ratios of lung cancer associated with radon levels of 25-49, 50-99 and 100 or more Bq/m 3 , were 1.13 (95% confidence interval; 0.29-4.40), 1.23 (0.16-9.39) and 0.25 (0.03-2.33), respectively. None of the estimates showed statistical significance, due to small sample size. When the subjects were limited to only include residents of more than 30 years, the estimates did not change substantially. This study did not find that the risk pattern of lung cancer, possibly associated with residential radon exposure, in Misasa Town differed from patterns observed in other countries. (author)

Association of Serum Uric Acid with Preeclampsia: A Case Control Study

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Razia Sultana

2013-07-01

Full Text Available Background: Preeclampsia (PE is still one of the important causes of maternal and fetal mortality in Bangladesh. Many researches have been done to identify a unique screening test that would predict the risk of developing PE before the classic symptoms appear. One of the most accessible and easiest screening tests is serum uric acid measurement. Numerous studies have demonstrated a relation between elevated maternal serum uric acid levels and adverse maternal and fetal outcome. Among several pathophysiologic factors the most commonly accepted explanation for hyperuricemia in PE is increased reabsorption and decreased excretion of uric acid.Objective: The aim of the present study was to assess the association of serum uric acid with preeclampsia.Materials and method: A case control study was conducted in the department of Biochemistry, Dhaka Medical College, Dhaka from July 2010 to June 2011. A total number of 100 pregnant women in third trimester of pregnancy attending in Obstetrics and Gynaecology department of Dhaka Medical College Hospital were selected purposively as study subjects. Among them 50 pregnant women with preeclampsia were selected as cases and 50 normal healthy pregnant women as controls.Results: Most of the study subjects were within 21 – 30 years of age group and mean age in case and control was 24.06±3.71 and 24.66±3.22 years respectively, which was not statistically different. Mean gestational age in case and control was 33.50±2.55 weeks and 33.60±2.95 weeks respectively, which was also not statistically different. Among the study subjects majority was primi in both groups (case 76%, contol 58% showing no statistical significance. Majority of the subjects in both groups were irregular in their antenatal checkup (case 52%, contol 40%. Uric acid concentration was measured in all the study subjects. The mean serum uric acid concentration in cases and controls were 7.01±1.90 mg/dl and 4.55±1.63 mg/dl respectively. This

Brain-relevant antibodies in first-episode psychosis: a matched case-control study.

Science.gov (United States)

Gaughran, Fiona; Lally, John; Beck, Katherine; McCormack, Ruaidhri; Gardner-Sood, Poonam; Coutinho, Ester; Jacobson, Leslie; Lang, Bethan; Sainz-Fuertes, Ricardo; Papanastasiou, Evangelos; Di Forti, Marta; Nicholson, Tim; Vincent, Angela; Murray, Robin M

2018-06-01

There has been much recent excitement about the possibility that some cases of psychosis may be wholly due to brain-reactive antibodies, with antibodies to N-methyl-D-aspartate receptor (NMDAR) and the voltage-gated potassium channel (VGKC)-complex reported in a few patients with first-episode psychosis (FEP). Participants were recruited from psychiatric services in South London, UK, from 2009 to 2011 as part of the Genetics and Psychosis study. We conducted a case-control study to examine NMDAR and VGKC-complex antibody levels and rates of antibody positivity in 96 patients presenting with FEP and 98 controls matched for age and sex. Leucine-rich glioma inactiviated-1 (LGI1) and contactin-associated protein (CASPR) antibodies were also measured. Notably, patients with suspicion of organic disease were excluded. VGKC-complex antibodies were found in both cases (n = 3) and controls (n = 2). NMDAR antibody positivity was seen in one case and one control. Either LGI1-Abs or CASPR2-Abs were found in three cases and three controls. Neuronal antibody staining, consistent with the above results or indicating potential novel antigens, was overall positive in four patients but also in six controls. Overall, antibody positivity was at low levels only and not higher in cases than in controls. This case-control study of the prevalence of antibodies in FEP does not provide evidence to support the hypothesis that FEP is associated with an immune-mediated process in a subgroup of patients. Nevertheless, as other bio-clinical factors may influence the effect of such antibodies in a given individual, and patients with organic neurological disease may be misdiagnosed as FEP, the field requires more research to put these findings in context.

Aetiology of handball injuries : a case-control study

NARCIS (Netherlands)

Dirx, M.; Bouter, L. M.; de Geus, G. H.

This article presents the results of a case-control study regarding the background to handball injuries among players of 12 years and older. Data were collected by means of a written questionnaire on the nature, location and direct causes of the injuries as well as information on risk factors.

Postnatal risk factors for testicular cancer: The EPSAM case-control study.

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Moirano, Giovenale; Zugna, Daniela; Grasso, Chiara; Mirabelli, Dario; Lista, Patrizia; Ciuffreda, Libero; Segnan, Nereo; Merletti, Franco; Richiardi, Lorenzo

2017-11-01

Testicular cancer is considered to originate from an impaired differentiation of fetal germ cells, but puberty could represent another time window of susceptibility. Our study aimed at investigating the association between environmental exposures acting during puberty/adolescence (13-19 years of age) and the risk of testicular cancer. We used data of the EPSAM study, a case-control study on germ-cell testicular cancer conducted in the province of Turin, Italy, involving cases diagnosed between 1997 and 2008. Histologically confirmed cases (n = 255) and controls (n = 459) completed a postal questionnaire focusing in particular on the pubertal period (namely age 13 years) with questions on physical activity (competitive sports, gardening), lifestyle (alcohol consumption, smoking), occupational history and medical conditions. All analyses were adjusted for the matching variables, cryptorchidism and educational level. Having done at least one competitive sport during puberty (odds ratio [OR]: 0.72, 95% confidence interval: 0.52-1.00), gardening activities during puberty (OR: 0.62, 0.42-0.94) and having a lower weight than peers during puberty (OR: 0.64, 0.42-0.97) were all inversely associated with the risk of testicular cancer. No evidence of association between smoking or alcohol consumption during puberty and the risk of testicular cancer was observed. Regarding agriculture-related occupations, we found an association with the risk of testicular cancer both for occasional jobs during puberty (OR: 2.40, 95% CI: 1.08-5.29) and ever employment in adolescence (OR: 2.59, 95% CI: 0.83-8.10). Our results suggest that postnatal exposures could play a role in testicular cancer aetiology, at least when acting in puberty or adolescence. © 2017 UICC.

Risk factors associated with non-alcoholic fatty liver disease in subjects from primary care units. A case-control study

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Bernad Jesús

2008-10-01

Full Text Available Abstract Background Non alcoholic fatty liver disease (NAFL consists in the accumulation of fat vacuoles in the cytoplasm of hepatocytes. Many etiologic factors are associated with NAFL, such as, the metabolic syndrome factors, medications, bariatric surgery, nutritional disorders. However, very little information is available on the clinical relevance of this disorder as a health problem in the general population. Methods and design The aim of the study is establish the risk factors most frequently associated with NAFL in a general adult population assigned to the primary care units and to investigate the relationship between each component of the metabolic syndrome and the risk of having a NAFL. A population based case-control, observational and multicenter study will be carried out in 18 primary care units from the "Area de Gestión del Barcelonés Nord y Maresme" (Barcelona attending a population of 360,000 inhabitants and will include 326 cases and 370 controls. Cases are defined as all subjects fulfilling the inclusion criteria and with evidence of fatty liver in an abdominal ultrasonography performed for any reason. One control will be randomly selected for each case from the population, matched for age, gender and primary care center. Controls with fatty liver or other liver diseases will be excluded. All cases and controls will be asked about previous hepatic diseases, consumption of alcohol, smoking and drugs, and a physical examination, biochemical analyses including liver function tests, the different components of the metabolic syndrome and the HAIR score will also be performed. Paired controls will also undergo an abdominal ultrasonography. Discussion This study will attempt to determine the factors most frequently associated with the presence of NAFL investigate the relationship between the metabolic syndrome and the risk of fatty liver and study the influence of the different primary care professionals in avoiding the evolution

Detection of erythrovirus B19 in thyroidectomy specimens from Graves' disease patients: a case-control study.

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Page, Cyril; Hoffmann, Thomas Walter; Benzerdjeb, Nassim; Duverlie, Gilles; Sevestre, Henri; Desailloud, Rachel

2013-08-01

Environmental factors, such as viruses, are thought to contribute to the development of thyroid autoimmunity. Erythrovirus B19 (EVB19) is suspected to be involved in Hashimoto's thyroiditis, but no direct evidence is available concerning the role of EVB19 infection in Graves' disease. The objective of this study was to investigate whether the presence of EVB19 is more frequent in thyroidectomy specimens of patients undergoing thyroidectomy for Graves' disease (cases) than for multinodular thyroid (controls). Serum and thyroidectomy specimens were prospectively collected from 64 patients referred for total thyroidectomy over a 5-year period (2007-2011) and were investigated retrospectively and blindly for circulating EVB19 DNA by q-PCR (Qiagen), and for EVB19 thyrocyte infection by immunochemistry (VP2-Antibody, Dako). EVB19 serology was also determined. General clinical and laboratory data were collected. Twenty patients were referred for Graves' disease and 44 patients were referred for non-autoimmune multinodular thyroid. Patients with thyroid cancer were excluded. Ten percent of Graves' disease patients and 27.7% of control patients had positive staining of thyrocytes for EVB19 antibodies (ns). EVB19-positive and EVB19-negative cases did not differ. EVB19-positive controls were older than EVB19-negative controls (mean age: 57.5 [35-74] vs. 45 [28-80] years, P=0.03) No case of acute EVB19 infection was identified. EVB19-positive serology was more frequent in controls than in Graves' disease patients (88% vs. 45%, PGraves' disease patients than in controls. Further studies are needed to determine the role of EVB19 infection in thyroid diseases. Copyright © 2013 Wiley Periodicals, Inc.

Misclassification of Case-Control Studies in Neurosurgery and Proposed Solutions.

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Esene, Ignatius Ngene; Mbuagbaw, Lawrence; Dechambenoit, Gilbert; Reda, Wael; Kalangu, Kazadi K

2018-04-01

Case-control studies (CCS) and cohort studies (CS) are common research designs in neurosurgery. But the term case-control study is frequently misused in the neurosurgical literature, with many articles reported as CCS, even although their methodology does not respect the basic components of a CCS. We sought to estimate the extent of these discrepancies in neurosurgical literature, explore factors contributing to mislabeling, and shed some light on study design reporting. We identified 31 top-ranking pure neurosurgical journals and searched them for articles reported as CCS, either in the title or in the abstract. The articles were read to determine if they really were CCS according to STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines. Article assessment was conducted in duplicate (agreement [κ statistics] = 99.82%). Two hundred and twenty-four articles met our inclusion criteria, 133 of which (59.38%) correctly labeled the case-control design, whereas 91 (40.62%) misclassified this study design. Cohort studies (CS) were the most common design mislabeled as case-control studies in 76 articles (33.93%), 57 of which (25.45%) were retrospective CS. The mislabeling of CCS impairs the appropriate indexing, classification, and sorting of evidence. Mislabeling CS for CCS leads to a downgrading of evidence as CS represent the highest level of evidence for observational studies. Odds ratios instead of relative risk are reported for these studies, resulting in a distortion of the measurement of the effect size, compounded when these are summarized in systematic reviews and pooled in meta-analyses. Many studies reported as CCS are not true CCS. Reporting guidelines should include items that ensure that studies are labeled correctly. STROBE guidelines should be implemented in assessment of observational studies. Researchers in neurosurgery need better training in research methods and terminology. We also recommend accrued vigilance from

An intronic single-nucleotide polymorphism (rs13217795) in FOXO3 is associated with asthma and allergic rhinitis: a case-case-control study.

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Amarin, Justin Z; Naffa, Randa G; Suradi, Haya H; Alsaket, Yousof M; Obeidat, Nathir M; Mahafza, Tareq M; Zihlif, Malek A

2017-11-15

Asthma and allergic rhinitis are respiratory diseases with a significant global burden. Forkhead box O3 (FOXO3) is a gene involved in the etiology of a number of respiratory diseases. The objective of this study is to assess the association of rs13217795, an intronic FOXO3 single-nucleotide polymorphism, with asthma and allergic rhinitis. In this case-case-control genetic association study, genotyping was conducted using the PCR-RFLP method. Genotype-based associations were investigated under the general, recessive, and dominant models of disease penetrance using binomial logistic regression; and, allele-based associations were tested using Pearson's chi-squared test. The final study population consisted of 94 controls, 124 asthmatics, and 110 allergic rhinitis patients. The general and recessive models of disease penetrance were statistically significant for both case-control comparisons. Under the general model, the odds of the asthma phenotype were 1.46 (0.64 to 3.34) and 3.42 (1.37 to 8.57) times higher in heterozygotes and derived allele homozygotes, respectively, compared to ancestral allele homozygotes. The corresponding odds ratios for the allergic rhinitis phenotype were 1.05 (0.46 to 2.40) and 2.35 (0.96 to 5.73), respectively. The dominant model of disease penetrance was not statistically significant. The minor allele in all study groups was the ancestral allele, with a frequency of 0.49 in controls. There was no deviation from Hardy-Weinberg equilibrium in controls. Both case-control allele-based associations were statistically significant. Herein we present the first report of the association between rs13217795 and allergic rhinitis, and the first independent verification of the association between rs13217795 and asthma. Marker selection in future genetic association studies of asthma and allergic rhinitis should include functional polymorphisms in linkage disequilibrium with rs13217795.

Estimating time-varying exposure-outcome associations using case-control data: logistic and case-cohort analyses

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Ruth H. Keogh

2016-01-01

Full Text Available Abstract Background Traditional analyses of standard case-control studies using logistic regression do not allow estimation of time-varying associations between exposures and the outcome. We present two approaches which allow this. The motivation is a study of vaccine efficacy as a function of time since vaccination. Methods Our first approach is to estimate time-varying exposure-outcome associations by fitting a series of logistic regressions within successive time periods, reusing controls across periods. Our second approach treats the case-control sample as a case-cohort study, with the controls forming the subcohort. In the case-cohort analysis, controls contribute information at all times they are at risk. Extensions allow left truncation, frequency matching and, using the case-cohort analysis, time-varying exposures. Simulations are used to investigate the methods. Results The simulation results show that both methods give correct estimates of time-varying effects of exposures using standard case-control data. Using the logistic approach there are efficiency gains by reusing controls over time and care should be taken over the definition of controls within time periods. However, using the case-cohort analysis there is no ambiguity over the definition of controls. The performance of the two analyses is very similar when controls are used most efficiently under the logistic approach. Conclusions Using our methods, case-control studies can be used to estimate time-varying exposure-outcome associations where they may not previously have been considered. The case-cohort analysis has several advantages, including that it allows estimation of time-varying associations as a continuous function of time, while the logistic regression approach is restricted to assuming a step function form for the time-varying association.

Mobile phone base stations and early childhood cancers: case-control study.

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Elliott, Paul; Toledano, Mireille B; Bennett, J; Beale, L; de Hoogh, K; Best, N; Briggs, D J

2010-06-22

To investigate the risk of early childhood cancers associated with the mother's exposure to radiofrequency from and proximity to macrocell mobile phone base stations (masts) during pregnancy. Case-control study. Cancer registry and national birth register data in Great Britain. 1397 cases of cancer in children aged 0-4 from national cancer registry 1999-2001 and 5588 birth controls from national birth register, individually matched by sex and date of birth (four controls per case). Incidence of cancers of the brain and central nervous system, leukaemia, and non-Hodgkin's lymphomas, and all cancers combined, adjusted for small area measures of education level, socioeconomic deprivation, population density, and population mixing. Mean distance of registered address at birth from a macrocell base station, based on a national database of 76,890 base station antennas in 1996-2001, was similar for cases and controls (1107 (SD 1131) m v 1073 (SD 1130) m, P=0.31), as was total power output of base stations within 700 m of the address (2.89 (SD 5.9) kW v 3.00 (SD 6.0) kW, P=0.54) and modelled power density (-30.3 (SD 21.7) dBm v -29.7 (SD 21.5) dBm, P=0.41). For modelled power density at the address at birth, compared with the lowest exposure category the adjusted odds ratios were 1.01 (95% confidence interval 0.87 to 1.18) in the intermediate and 1.02 (0.88 to 1.20) in the highest exposure category for all cancers (P=0.79 for trend), 0.97 (0.69 to 1.37) and 0.76 (0.51 to 1.12), respectively, for brain and central nervous system cancers (P=0.33 for trend), and 1.16 (0.90 to 1.48) and 1.03 (0.79 to 1.34) for leukaemia and non-Hodgkin's lymphoma (P=0.51 for trend). There is no association between risk of early childhood cancers and estimates of the mother's exposure to mobile phone base stations during pregnancy.

The Association Between Urban Tree Cover and Gun Assault: A Case-Control and Case-Crossover Study.

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Kondo, Michelle C; South, Eugenia C; Branas, Charles C; Richmond, Therese S; Wiebe, Douglas J

2017-08-01

Green space and vegetation may play a protective role against urban violence. We investigated whether being near urban tree cover during outdoor activities was related to being assaulted with a gun. We conducted geographic information systems-assisted interviews with boys and men aged 10-24 years in Philadelphia, Pennsylvania, including 135 patients who had been shot with a firearm and 274 community controls, during 2008-2011. Each subject reported a step-by-step mapped account of where and with whom they traveled over a full day from waking until being assaulted or going to bed. Geocoded path points were overlaid on mapped layers representing tree locations and place-specific characteristics. Conditional logistic regressions were used to compare case subjects versus controls (case-control) and case subjects at the time of injury versus times earlier that day (case-crossover). When comparing cases at the time of assault to controls matched at the same time of day, being under tree cover was inversely associated with gunshot assault (odds ratio (OR) = 0.70, 95% confidence interval (CI): 0.55, 0.88), especially in low-income areas (OR = 0.69, 95% CI: 0.54, 0.87). Case-crossover models confirmed this inverse association overall (OR = 0.55, 95% CI: 0.34, 0.89) and in low-income areas (OR = 0.54, 95% CI: 0.33, 0.88). Urban greening and tree cover may hold promise as proactive strategies to decrease urban violence. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Risk factors for measles among adults in Tianjin, China: Who should be controls in a case-control study?

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Wagner, Abram L; Boulton, Matthew L; Gillespie, Brenda W; Zhang, Ying; Ding, Yaxing; Carlson, Bradley F; Luo, Xiaoyan; Montgomery, JoLynn P; Wang, Xiexiu

2017-01-01

Control groups in previous case-control studies of vaccine-preventable diseases have included people immune to disease. This study examines risk factors for measles acquisition among adults 20 to 49 years of age in Tianjin, China, and compares findings using measles IgG antibody-negative controls to all controls, both IgG-negative and IgG-positive. Measles cases were sampled from a disease registry, and controls were enrolled from community registries in Tianjin, China, 2011-2015. Through a best subsets selection procedure, we compared which variables were selected at different model sizes when using IgG-negative controls or all controls. We entered risk factors for measles in two separate logistic regression models: one with measles IgG-negative controls and the other with all controls. The study included 384 measles cases and 1,596 community controls (194 IgG-negative). Visiting a hospital was an important risk factor. For specialty hospitals, the odds ratio (OR) was 4.53 (95% confidence interval (CI): 1.28, 16.03) using IgG-negative controls, and OR = 5.27 (95% CI: 2.73, 10.18) using all controls. Variables, such as age or length of time in Tianjin, were differentially selected depending on the control group. Individuals living in Tianjin ≤3 years had 2.87 (95% CI: 1.46, 5.66) times greater odds of measles case status compared to all controls, but this relationship was not apparent for IgG-negative controls. We recommend that case-control studies examining risk factors for infectious diseases, particularly in the context of transmission dynamics, consider antibody-negative controls as the gold standard.

[Application of nested case-control study on safe evaluation of post-marketing traditional Chinese medicine injection].

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Xiao, Ying; Zhao, Yubin; Xie, Yanming

2011-10-01

The nested case-control study design (or the case-control in a cohort study) is described here as a new study design used in safe evaluation of post-marketing traditional Chinese medicine injection. In the nested case-control study, cases of a disease that occur in a defined cohort are identified and, for each, a specified number of matched controls is selected from among those in the cohort who have not developed the disease by the time of disease occurrence in the case. For many research questions, the nested case-control design potentially offers impressive reductions in costs and efforts of data collection and analysis compared with the full cohort approach, with relatively minor loss in statistical efficiency. The nested case-control design is particularly advantageous for studies in safe evaluation of post-marketing traditional Chinese medicine injection. Some examples of the application of nested case-control study were given.

Chronic autoimmune disorders are increased in coeliac disease: A case-control study.

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Bibbò, Stefano; Pes, Giovanni Mario; Usai-Satta, Paolo; Salis, Roberta; Soro, Sara; Quarta Colosso, Bianca Maria; Dore, Maria Pina

2017-11-01

Coeliac disease (CD) is an autoimmune disorder of the small bowel associated with increased risk of additional autoimmune diseases (ADs).To investigate the prevalence of ADs in a population of adult coeliac patients.This was a retrospective case-control study. Data from coeliac patients and controls referred to a tertiary center between 2013 and 2016 were collected. The frequency of ADs and the unadjusted and adjusted odds ratios (ORs) for age, gender, disease duration, and body mass index with their 95% confidence intervals (CIs) were evaluated.Two hundred fifty-five patients with CD (median age 37.1 years; 206 women) were matched with 250 controls. ADs were more frequent (35.3%) in coeliac patients than in controls (15.2%). Adjusted ORs for the presence of only 1, at least 1, and more than 1 AD were 3.13 (95% CI 1.81-5.42, P disease. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Case-control study of genus-beta human papillomaviruses in plucked eyebrow hairs and cutaneous squamous cell carcinoma.

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Iannacone, Michelle R; Gheit, Tarik; Pfister, Herbert; Giuliano, Anna R; Messina, Jane L; Fenske, Neil A; Cherpelis, Basil S; Sondak, Vernon K; Roetzheim, Richard G; Silling, Steffi; Pawlita, Michael; Tommasino, Massimo; Rollison, Dana E

2014-05-01

Cutaneous human papillomaviruses (HPV) have been reported in cutaneous squamous cell carcinoma (SCC). We conducted a clinic-based case-control study to investigate the association between genus-beta HPV DNA in eyebrow hairs (EBH) and SCC. EBH from 168 SCC cases and 290 controls were genotyped for genus-beta HPV DNA. SCC tumors from a subset of cases (n = 142) were also genotyped. Viral load was determined in a subset of specimens positive for a single HPV type. Associations with SCC were estimated by odds ratios (OR) and 95% confidence intervals (CI) adjusted for age and sex using logistic regression. Statistical tests were two-sided. EBH DNA prevalence was greater in cases (87%) than controls (73%) (p genus-beta types tested, when accounting for DNA for the same HPV type in the tumor (ORs = 3.44-76.50). Compared to controls, the mean viral DNA load in EBH among the selected cases was greater for HPV5, HPV8 and HPV24, but lower for HPV38. SCC cases were more likely than controls to have HPV DNA+ EBH for single and multiple HPV types, providing additional support for the potential role of genus-beta HPV infections in SCC development. © 2013 UICC.

Baldness and testicular cancer: the EPSAM case-control study.

Science.gov (United States)

Moirano, G; Zugna, D; Grasso, C; Lista, P; Ciuffreda, L; Segnan, N; Merletti, F; Richiardi, L

2016-03-01

The etiology of testicular cancer is largely unexplained. Research has mainly focused on prenatal exposures, especially to sex hormones, while less attention has been paid to exposures that may act also postnatally. As baldness has been previously associated with testicular cancer risk we focused on baldness and body hairiness, which are both associated with androgen activity. We used data of the Postnatal Exposures and Male Health (EPSAM) study, a case-control study on testicular cancer conducted in the Province of Turin, Italy, involving cases diagnosed between 1997 and 2008. Information was collected using mailed questionnaires. Analyses included 255 cases and 459 controls. We calculated ORs and 95% CIs to estimate testicular cancer risk among those who developed baldness and among those with body hairiness. We found an inverse association between testicular cancer and baldness (OR: 0.67, 95% CI: 0.46-0.98) and body hairiness (OR: 0.78, 95% CI: 0.53-1.16), although the latter had wider CIs. The inverse association between baldness and testicular cancer is consistent with the results from previous studies. These results suggest that androgens activity may influence testicular cancer risk. © 2016 American Society of Andrology and European Academy of Andrology.

The lack of selection bias in a snowball sampled case-control study on drug abuse.

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Lopes, C S; Rodrigues, L C; Sichieri, R

1996-12-01

Friend controls in matched case-control studies can be a potential source of bias based on the assumption that friends are more likely to share exposure factors. This study evaluates the role of selection bias in a case-control study that used the snowball sampling method based on friendship for the selection of cases and controls. The cases selected fro the study were drug abusers located in the community. Exposure was defined by the presence of at least one psychiatric diagnosis. Psychiatric and drug abuse/dependence diagnoses were made according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R) criteria. Cases and controls were matched on sex, age and friendship. The measurement of selection bias was made through the comparison of the proportion of exposed controls selected by exposed cases (p1) with the proportion of exposed controls selected by unexposed cases (p2). If p1 = p2 then, selection bias should not occur. The observed distribution of the 185 matched pairs having at least one psychiatric disorder showed a p1 value of 0.52 and a p2 value of 0.51, indicating no selection bias in this study. Our findings support the idea that the use of friend controls can produce a valid basis for a case-control study.

Maternal complication prevention: evidence from a case-control study in southwest Nigeria

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Kayode O. Osungbade

2014-12-01

Full Text Available Background: The importance of strengthening maternal health services as a preventive intervention for morbidities and complications during pregnancy and delivery in developing countries cannot be over-emphasised, since use of prenatal health services improves maternal health outcomes. Aim: This study investigated differences in risk factors for maternal complications in booked and unbooked pregnant women in Nigeria, and provided evidence for their prevention. Setting: The study was carried out in a postnatal ward in a secondary health facility. Methods: This was a case-control study involving booked and unbooked pregnant women who had delivered. Consecutive enrolment of all unbooked pregnant women (cases was done, and one booked pregnant woman (control was enrolled and matched for age with each of these. Both groups were interviewed using a questionnaire, whilst records of delivery were extracted from the hospital files. Findings were subjected to logistical regression at a significance level of p < 0.05. Results: Booked women had a lower median length of labour (10 hours compared to unbooked women (13 hours. More women in the booked control group (139; 35.1% than in the unbooked case group (96; 23.6% reported at least one type of morbidity during the index pregnancy (p = 0.0004. Booking status was associated with a likelihood of spontaneous vaginal delivery. Young maternal age, low education, rural residence and low socio-economic status were associated with less likelihood of using prenatal services. Young maternal age, low education and intervention in the delivery were associated with a likelihood of experiencing a complication of delivery. Conclusion: Strengthening antenatal and secondary healthcare services as short- and mediumterm measures might be cost-effective as a preventive strategy in complications of pregnancy,whilst socio-economic dimensions of health are accorded priority in the long term.

Association between Myocardial Infarction and Periodontitis: a Meta-Analysis of Case-Control Studies

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Quan Shi

2016-11-01

Full Text Available AbstractBackground and Objective: Many clinical researches have been carried out to investigate the relationship between myocardial infarction (MI and periodontitis. Despite most of them indicated that the periodontitis may be associated with an increased risk of MI, the findings and study types of these studies have been inconsistent. The goal of this meta-analysis was to critically assess the strength of the association between MI and periodontitis in case-control studies.Methods: PubMed and the Cochrane Library were searched for eligible case-control studies reporting relevant parameters that compared periodontal status between MI and control subjects. The odds ratios (ORs and 95% confidence intervals (CIs from each study were pooled to estimate the strength of the association between MI and periodontitis. The mean differences and 95% CIs for periodontal-related parameters were calculated to determine their overall effects.Results: Seventeen studies including a total of 3456 MI patients and 3875 non-MI control subjects were included. The pooled OR for the association between MI and periodontitis was 2.531 (95% CI: 1.927-3.324. The mean differences (95% CIs for clinical attachment loss, probing depth, bleeding on probing, plaque index, and the number of missing teeth were 1.000 (0.726-1.247, 1.209 (0.538-1.880, 0.342 (0.129-0.555, 0.383 (0.205-0.560, and 4.122 (2.012-6.232, respectively. Conclusion: With the current evidence, the results support the presence of a significant association between MI and periodontitis. Moreover, MI patients had worse periodontal and oral hygiene status and fewer teeth than did control subjects. More high-quality and well-designed studies focusing on the casual relationship between MI and periodontitis should be conducted in the future.

Risk factors for idiopathic orbital inflammation: a case-control study

NARCIS (Netherlands)

Bijlsma, Ward R.; van Gils, Carla H.; Paridaens, Dion; Mourits, Maarten P.; Kalmann, Rachel

2011-01-01

Objective To identify risk factors involved in the development of idiopathic orbital inflammation (IOI). Methods Case-control study of 69 adults who had had a first episode of IOI and 296 adult controls with rhegmatogenous retinal detachment (RD) selected from three orbital centres in The

Individual socioeconomic status and breast cancer diagnostic stages: a French case-control study.

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Orsini, Mattea; Trétarre, Brigitte; Daurès, Jean-Pierre; Bessaoud, Faiza

2016-06-01

Health inequalities have increased over the last 30 years. Our goal was to investigate the relationship between low individual socioeconomic status and poor breast cancer prognosis. Our hypothesis was: low socioeconomic status patients have a higher risk of being diagnosed with late stage breast cancer than high socioeconomic status ones due to delayed diagnosis. We conducted a matched case-control study on 619 women with breast cancer, living in the Hérault, a French administrative area. Both Cases and Controls were recruited among invasive cases diagnosed in 2011 and 2012 and treated in Hérault care centers. Cases were defined as patients with advanced stages. Controls were composed of early stage patients. Individual socioeconomic status was assessed using a validated individual score adapted to the French population and health care system. We observed that low socioeconomic status patients have a 2-fold risk of having late stage breast cancer regardless of cancer characteristics and detection mode (screening vs. clinical signs). One reason explaining those results could be that low socioeconomic status patients have less regular follow-up which can lead to later and poorer diagnosis. Follow-up is improved for women with a better awareness of breast cancer. Health policy makers could reduce health inequalities by reducing the delay in breast cancer diagnosis for low socioeconomic status women. © The Author 2016. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Autism in children and correlates in Lebanon: a pilot case-control study.

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Hamadé, Aline; Salameh, Pascale; Medlej-Hashim, Myrna; Hajj-Moussa, Elie; Saadallah-Zeidan, Nina; Rizk, Francine

2013-09-17

Autism spectrum disorder (ASD) is a neurological disorder typically appearing before the age of three. The exact cause of autism remains uncertain, and several factors may be involved in its onset: genetic factors and possible environmental factors. The aim of this study was to assess the correlates of autism in the Lebanese population. We investigated the association of autism with several factors in 86 autism cases from specialized schools for children with developmental disabilities and 172 control children from regular public schools in the same regions. Several risk factors for autism were investigated after comparison with a cohort control on parental age, sex, maternal unhappy feeling during pregnancy, consanguineous marriage, and province of residence. The Chi-square test was used to compare nominal variables, and Fisher exact test was used in case expected values within cells were inferior to five. For quantitative variables, we used t-test to compare means between two groups, after checking their distribution normality. For multivariate analysis, we used a forward stepwise likelihood ratio logistic regression. We observed male predominance (79.1%) among autistic infants. There was a significant association between autism and older parents age (OR=1.27), male sex (OR=3.38), unhappy maternal feeling during pregnancy (OR=5.77), living close to industry (OR=6.58), previous childhood infection (OR=8.85), but none concerning maternal age, paternal age and consanguinity. In this pilot epidemiological study of autism in Lebanon, we found several prenatal and perinatal risk factors for autism that could be modified.

Toxoplasma gondii seroprevalence and association with equine protozoal myeloencephalitis: A case-control study of Californian horses.

Science.gov (United States)

James, K E; Smith, W A; Packham, A E; Conrad, P A; Pusterla, N

2017-06-01

While toxoplasmosis is not commonly considered a clinical disease of equines, previous seroprevalence studies have reported differing background rates of Toxoplasma gondii infection in horses globally. The objective of this study was to evaluate possible associations between T. gondii seroprevalence and clinical signs of equine protozoal myeloencephalitis (EPM) in horses. Using a case-control study design, 720 Californian horses with neurologic signs compatible with EPM were compared to healthy, non-neurologic horses for the presence of T. gondii antibodies (using indirect fluorescent antibody tests [IFAT]). Toxoplasma gondii seroprevalence among cases and controls was determined at standard serum cut-offs: 40, 80, 160, 320, and 640. At a T. gondii titre cut-off of 320, horses with clinical signs compatible with EPM had 3.55 times the odds of a seropositive test compared to those without clinical signs (Pequines. Serologic testing of cerebrospinal fluid and isolation of T. gondii in EPM suspect cases should be considered. Future studies investigating the relationship between T. gondii and EPM are warranted. Copyright © 2017 Elsevier Ltd. All rights reserved.

A case-control study: occupational cooking and the risk of uveal melanoma

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Marr Anja

2010-10-01

Full Text Available Abstract Background A European-wide population based case-control study (European rare cancer study undertaken in nine European countries examined risk factors for uveal melanoma. They found a positive association between cooks and the risk of uveal melanoma. In our study we examine whether cooks or people who worked in cook related jobs have an increased uveal melanoma risk. Methods We conducted a case-control study during 2002 and 2005. Overall, 1653 eligible subjects (age range: 20-74 years, living in Germany participated. Interviews were conducted with 459 incident uveal melanoma cases, 827 population controls, 180 ophthalmologist controls and 187 sibling controls. Data on occupational exposure were obtained from a self-administered postal questionnaire and a computer-assisted telephone interview. We used conditional logistic regression to estimate odds ratios adjusting for the matching factors. Results Overall, we did not observe an increased risk of uveal melanoma among people who worked as cooks or who worked in cook related jobs. When we restricted the source population of our study to the population of the Federal State of Northrhine-Westphalia, we observed an increased risk among subjects who were categorized as cooks in the cases-control analysis. Conclusion Our results are in conflict with former results of the European rare cancer study. Considering the rarity of the disease laboratory in vitro studies of human uveal melanoma cell lines should be done to analyze potential exposure risk factors like radiation from microwaves, strong light from incandescent ovens, or infrared radiation.

Circulating folate levels and colorectal adenoma: a case-control study and a meta-analysis.

Science.gov (United States)

Park, Yeong Mi; Youn, Jiyoung; Cho, Chang Ho; Kim, Sung Hi; Lee, Jung Eun

2017-10-01

The relationship between folate and colorectal neoplasia remains controversial. We examined the association between serum folate concentrations and colorectal adenomas in a case-control study of Korean adults and conducted a meta-analysis. Our case-control study included 113 pairs of case and control who underwent colonoscopy and provided blood samples. We used multivariable conditional logistic regression models to obtain the odds ratios and 95% confidence interval (CIs). For meta-analysis, we identified the relevant studies by searching the PubMed database up to February 2017, included our case-control study and combined the study-specific relative risks (RRs) using a random-effects model. In this case-control study, we included 58 men and 55 women with colorectal adenomas and sex and fasting status matched the controls. We did not find any significant association between the serum folate levels and colorectal adenomas in either men or women. For meta-analysis, a total of eleven studies were included in our analysis and classified into two groups; polyp clearance group (PC) for the studies that included participants who underwent endoscopies and had their polyps removed at baseline; and no polyp clearance group (NPC) for the studies that included participants whose histories of endoscopies were unknown or who underwent their first endoscopies. Four PC (1,311 cases and 1,672 non-cases) and eight NPC studies (3,501 cases and 11,347 non-cases) were included. The combined RRs (95% CIs) comparing the bottom with the top categories of circulating folate levels were 1.07 (0.97-1.18) for the NPC group but 1.45 (1.16-1.74) for the PC group. Low circulating folate levels were associated with new adenoma formation.

Developmental origins of polycystic ovary syndrome (PCOS), a case control study comparing birth weight in women with PCOS and control group.

Science.gov (United States)

Sadrzadeh, Sheda; Painter, Rebecca C; Lambalk, Cornelis B

2016-10-01

Evidence from various epidemiological studies and experimental animal studies has linked adverse intrauterine circumstances with health problems in adult life. This field of investigation is known as Developmental Origins of Health and Disease (DOHaD). Studies investigating the relation between developing polycystic ovary syndrome (PCOS) in adulthood and birth weight have yielded inconsistent results: PCOS is described more often in women with low birth weight and high birth weight, while other studies have failed to establish any relation. In this retrospective case-control study, we evaluated whether women diagnosed with PCOS had lower birth weight compared to women with a regular menstrual cycle (controls). Binary logistic regression models were used to analyze the data and correct for known confounders. About 65 women with PCOS and 96 controls were recruited for this purpose. The average birth weight of PCOS women (3357 g) did not differ from the average birth weight of controls (3409 g). Mean age at menarche differed significantly between groups, 13.7  years and 12.8  years (p = 0.006), respectively, for PCOS women and controls. In conclusion, we could not confirm the effect of adverse intrauterine conditions, reflected in birth weight, on developing PCOS.

Maternal periodontal disease and preterm birth: A case-control study

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Pushpalatha Govindaraju

2015-01-01

Full Text Available Background and Objective: Preterm birth (PTB is an important issue in public health and is a major cause for infant mortality and morbidity. There is a growing consensus that systemic diseases elsewhere in the body may influence PTB. Recent studies have hypothesized that maternal periodontitis could be a high-risk factor for PTB. The aim of the present study was to investigate the relationship between maternal periodontitis on PTB. Materials and Methods: Forty systemically healthy primiparous mothers aged 18–35 years were recruited for the study. Based on inclusion and exclusion criteria, they were categorized into PTB group as cases and full term birth group (FTB as controls. PTB cases (n = 20 defined as spontaneous delivery before/<37 completed weeks of gestation. Controls (FTB were normal births at or after 37 weeks of gestation. Data on periodontal status, pregnancy outcome variables, and information on other factors that may influence adverse pregnancy outcomes were collected within 2 days of labor. Data were subjected to Student's t-test and Pearson's correlation coefficient statistical analysis. Results: Statistically significant difference with respect to the gestational period at the time of delivery and birth weight of the infants in (PTB group (<0.001 compared to (FTB group was observed. Overall, there was statistically significant poor periodontal status in the (PTB group compared to (FTB group. The statistical results also showed a positive correlation between gestational age and clinical parameters. Conclusion: An observable relationship was noticed between periodontitis and gestational age, and a positive correlation was found with respect to PTB and periodontitis. Further studies should be designed to establish periodontal disease as an independent risk factor for PTB/preterm low birth weight.

Campylobacteriosis in New Zealand: results of a case-control study.

OpenAIRE

Eberhart-Phillips, J; Walker, N; Garrett, N; Bell, D; Sinclair, D; Rainger, W; Bates, M

1997-01-01

STUDY OBJECTIVE: To identify and assess the contributions of major risk factors for campylobacteriosis in New Zealand. DESIGN: Case-control study. Home interviews were conducted over nine months using a standardised questionnaire to assess recent food consumption and other exposures. SETTING: Four centres in New Zealand with high notification rates of campylobacter infections--Auckland, Hamilton, Wellington, and Christchurch. PARTICIPANTS: Case patients were 621 people notified between 1 June...

Risk factors for neural tube defects in Riyadh City, Saudi Arabia: Case-control study.

Science.gov (United States)

Salih, Mustafa A M; Murshid, Waleed R; Mohamed, Ashry Gad; Ignacio, Lena C; de Jesus, Julie E; Baabbad, Rubana; El Bushra, Hassan M

2014-01-01

Both genetic and non-genetic environmental factors are involved in the etiology of neural tube defects (NTD) which affect 0.5-2/1000 pregnancies worldwide. This study aimed to explore the risk factors for the development of NTD in Saudi population, and highlight identifiable and preventable causes. Similar studies are scarce in similar populations ofthe Arabian Peninsula and North Africa. This is an unmatched concurrent case-control study including NTD cases born at King Khalid University Hospital, Riyadh during a 4-year period (2002-2006). The case-control study included 25 cases and 125 controls (case: control ratio of 1:5). Years of formal education, employment, household environment (including availability of air conditioning) and rate of parental consanguinity did not differ between mothers of cases and controls. Significantly higher proportion of mothers of cases had history of stillbirth compared to control mothers (16% vs 4.1%, P=0.02). Also family history of hydrocephalus and congenital anomalies were more prevalent in cases than controls (P values=0.0000 and 0.003, respectively). There was significant protective effect of periconceptional folic acid consumption both prior to conception (OR 0.02, 95% CI 0.00-0.07) and during the first 6 weeks of conception (OR 0.13, 95% CI 0.04-0.39). Further research, including a larger cohort, is required to enable ascertainment of gene-nutrient and gene environment interactions associated with NTD in Saudi Arabia.

Potential risk factors for diabetic neuropathy: a case control study

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Nooraei Mahdi

2005-12-01

Full Text Available Abstract Background Diabetes mellitus type II afflicts at least 2 million people in Iran. Neuropathy is one of the most common complications of diabetes and lowers the patient's quality of life. Since neuropathy often leads to ulceration and amputation, we have tried to elucidate the factors that can affect its progression. Methods In this case-control study, 110 diabetic patients were selected from the Shariati Hospital diabetes clinic. Michigan Neuropathic Diabetic Scoring (MNDS was used to differentiate cases from controls. The diagnosis of neuropathy was confirmed by nerve conduction studies (nerve conduction velocity and electromyography. The multiple factors compared between the two groups included consumption of angiotensin converting enzyme inhibitors (ACEI, blood pressure, serum lipid level, sex, smoking, method of diabetes control and its quality. Results Statistically significant relationships were found between neuropathy and age, gender, quality of diabetes control and duration of disease (P values in the order: 0.04, 0.04, Conclusion In this study, hyperglycemia was the only modifiable risk factor for diabetic neuropathy. Glycemic control reduces the incidence of neuropathy, slows its progression and improves the diabetic patient's quality of life. More attention must be paid to elderly male diabetic patients with poor diabetes control with regard to regular foot examinations and more practical education.

Possible environmental, occupational, and other etiologic factors for Parkinson's disease: a case-control study in Germany.

Science.gov (United States)

Seidler, A; Hellenbrand, W; Robra, B P; Vieregge, P; Nischan, P; Joerg, J; Oertel, W H; Ulm, G; Schneider, E

1996-05-01

In a case-control study, we investigated the possible etiologic relevance to Parkinson's disease (PD) of rural factors such as farming activity, pesticide exposures, well-water drinking, and animal contacts; toxicologic exposures such as wood preservatives, heavy metals, and solvents; general anesthesia; head trauma; and differences in the intrauterine environment. We recruited 380 patients in nine German clinics, 379 neighborhood control subjects, and 376 regional control subjects in the largest case-control study investigating such factors and collected data in structured personal interviews using conditional logistic regression to control for educational status and cigarette smoking. The latter was strongly inversely associated with PD. There were significantly elevated odds ratios (OR) for pesticide use, in particular, for organochlorines and alkylated phosphates, but no association was present between PD and other rural factors. A significantly elevated OR was present for exposure to wood preservatives. Subjective assessment by the probands indicated that exposure to some heavy metals, solvents, exhaust fumes, and carbon monoxide was significantly more frequent among patients than control subjects, but this was not confirmed by a parallel assessment of job histories according to a job exposure matrix. Patients had undergone general anesthesia and suffered severe head trauma more often than control subjects, but a dose-response gradient was not present. Patients reported a significantly larger number of amalgam-filled teeth before their illness than control subjects. The frequency of premature births and birth order did not differ between patients and control subjects. Patients reported significantly more relatives affected with PD than control subjects. These results support a role for environmental and genetic factors in the etiology of PD.

What factors play a role in preventing self-immolation?Results from a case-control study in Iran

Directory of Open Access Journals (Sweden)

Hosein Karim

2015-07-01

Full Text Available Abstract: Background: To investigate factors related to prevention of self-immolation in west of Iran. Methods: In a case-control study, 30 consecutive cases of deliberate self-inflicted burns admitted to the regional burn center (Imam Khomeini hospital in Kermanshah province, Iran were compared with controls selected from the community and matched by sex, age,district-county of residence, and rural vs urban living environment. The following characteristics relevant to preventing self immolation were collected from all cases and controls: main domestic fuel used in the household, awareness about complications of burn injuries, and use of counseling services. Results: Descriptive analyses revealed that kerosene was the main domestic fuel in the household for 83% of cases. Not surprisingly, the main means of self-immolation in 93% of the patients was kerosene, with other fuels such as petrol and domestic gas used in remaining cases. The majority of cases and controls were aware of the potential complications of burn injuries. Use of counseling services was more common in controls. Conclusions: All three aspects of preventing self-immolation – having kerosene and other fuels in the home, being aware of the complications of burn injuries, and using counseling services were present in both the cases and controls. This suggests a large portion of residents in rural Iran are potential self-immolation victims. Increasing preventive strategies may reduce risk of suicide by self-immolation.

Comparative study of control selection in a national population-based case-control study: Estimating risk of smoking on cancer deaths in Chinese men.

Science.gov (United States)

Jiang, Jingmei; Liu, Boqi; Nasca, Philip C; Han, Wei; Zou, Xiaonong; Zeng, Xianjia; Tian, Xiaobing; Wu, Yanping; Zhao, Ping; Li, Junyao

2009-10-28

To assess the validation of a novel control selection design by comparing the consistency between the new design and a routine design in a large case-control study that was incorporated into a nationwide mortality survey in China. A nationwide mortality study was conducted during 1989-1991. Surviving spouses or other relatives of all adults who died during 1986-1988 provided detailed information about their own as well as the deceased person's smoking history. In this study, 130,079 males who died of various smoking-related cancers at age 35 or over were taken as cases, while 103,248 male surviving spouses (same age range with cases) of women who died during the same period and 49,331 males who died from causes other than those related to smoking were used as control group 1 and control group 2, respectively. Consistency in the results when comparing cases with each of the control groups was assessed. Consistency in the results was observed in the analyses using different control groups although cancer deaths varied with region and age. Equivalence could be ascertained using a 15% criterion in most cancer deaths which had high death rates in urban areas, but they were uncertain for most cancers in rural areas irrespective of whether the hypothesis testing showed significant differences or not. Sex-matched living spouse control design as an alternative control selection for a case-control study is valid and feasible, and the basic principles of the equivalence study are also supported by epidemiological survey data.

Effect of anterior cervical osteophyte in poststroke dysphagia: a case-control study.

Science.gov (United States)

Kim, Youngkook; Park, Geun-Young; Seo, Yu Jung; Im, Sun

2015-07-01

To investigate whether the concomitant presence of anterior cervical osteophytes can influence the severity and outcome of patients with poststroke dysphagia. Retrospective case-control study. Hospital. A total of 40 participants were identified (N=40). Patients with poststroke dysphagia with anterior cervical osteophytes (n=20) were identified and matched by age, sex, location, and laterality of the stroke lesion to a poststroke dysphagia control group with no anterior cervical osteophytes (n=20). Not applicable. Videofluoroscopic swallowing study, Functional Oral Intake Scale (FOIS), and Penetration-Aspiration Scale results assessed within the first month of stroke were analyzed. The FOIS at 6 months was recorded, and severity of dysphagia was compared between the 2 groups. The case group had larger degrees of postswallow residues in the valleculae and pyriform sinuses (P=.020 and Pdysphagia (OR=15.375; 95% CI, 3.195-infinity). The presence of anterior cervical osteophytes, which may cause mechanical obstruction and interfere with residue clearance at the valleculae and pyriform sinuses and result in more postswallow aspiration, may influence initial severity and outcome of poststroke dysphagia. The presence of anterior cervical osteophytes may be considered an important clinical condition that may affect poststroke dysphagia rehabilitation. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Microbial Characteristics of Peri-Implantitis : A Case-Control Study

NARCIS (Netherlands)

de Waal, Y C M; Eijsbouts, H V L C; Winkel, E G; van Winkelhoff, A J

BACKGROUND: Aim of this case-control study was to compare oral microbiological characteristics of subjects with healthy peri-implant conditions and subjects with peri-implantitis and to explore the influence of various patient-related and implant-related factors on the microbiological

Genetic variation at CYP3A is associated with age at menarche and breast cancer risk: a case-control study

OpenAIRE

Johnson, N. (Nichola); Dudbridge, Frank; Orr, Nick; Gibson, Lorna; Jones, Michael; Schoemaker, Minouk; Folkerd, E.J. (Elizabeth J.); Haynes, B.P. (Ben P.); Hopper, John; Southey, Melissa; Dite, G.S. (Gillian S.); Apicella, C. (Carmel); Schmidt, Marjanka; Broeks, Annegien; Veer, Laura

2014-01-01

textabstractINTRODUCTION: We have previously shown that a tag single nucleotide polymorphism (rs10235235), which maps to the CYP3A locus (7q22.1), was associated with a reduction in premenopausal urinary estrone glucuronide levels and a modest reduction in risk of breast cancer in women age ≤50 years.METHODS: We further investigated the association of rs10235235 with breast cancer risk in a large case control study of 47,346 cases and 47,570 controls from 52 studies participating in the Breas...

Genetic variation at CYP3A is associated with age at menarche and breast cancer risk: A case-control study

OpenAIRE

Johnson, Nichola; Dudbridge, Frank; Orr, Nick; Gibson, Lorna; Jones, Michael; Schoemaker, Minouk; Folkerd, E.J. (Elizabeth J.); Haynes, B.P. (Ben P.); Hopper, John; Southey, Melissa; Dite, Gillian; Apicella, Carmel; Schmidt, Marjanka; Broeks, Annegien; Veer, Laura

2014-01-01

textabstractIntroduction: We have previously shown that a tag single nucleotide polymorphism (rs10235235), which maps to the CYP3A locus (7q22.1), was associated with a reduction in premenopausal urinary estrone glucuronide levels and a modest reduction in risk of breast cancer in women age ≤50 years. Methods: We further investigated the association of rs10235235 with breast cancer risk in a large case control study of 47,346 cases and 47,570 controls from 52 studies participating in the Brea...

Social capital and adverse treatment outcomes of tuberculosis: a case-control study.

Science.gov (United States)

Deshmukh, P R; Mundra, A; Dawale, A

2017-08-01

'Social capital' refers to social norms, relationships, networks and values that affect the functioning and development of society. Social capital influences health positively, but its role in the treatment outcomes of tuberculosis (TB) is not known. To study the role of social capital in determining adverse TB treatment outcomes. Of 516 patients registered under the Revised National Tuberculosis Control Programme in 2014 in Wardha Tuberculosis Unit, Wardha, India, we included 88 patients with adverse treatment outcomes as cases and 187 controls from among those without adverse outcomes. Multiple logistic regression was used to compare standardised Z-scores. A greater proportion of controls than cases belonged to higher quartiles of social capital and its domains than cases, and the mean standardised Z-score was also consistently higher among controls than cases. Respectively 47% and 15% of cases and controls were in the poorest quartile of social capital, whereas respectively 10% and 33% of cases and controls were in the richest quartile. Each unit increase in Z-score of overall social capital reduced the odds of adverse treatment outcomes by 63.1%. Appropriate interventions for building social capital for TB patients and linking them with the programme would improve programme performance.

Hygiene behaviour and hospitalized severe childhood diarrhoea: a case-control study.

OpenAIRE

Baltazar, J. C.; Tiglao, T. V.; Tempongko, S. B.

1993-01-01

The relationship between personal and domestic hygiene behaviour and hospitalized childhood diarrhoea was examined in a case-control study of 356 cases and 357 controls from low-income families in metropolitan Manila. Indices of hygiene behaviour were defined for overall cleanliness, kitchen hygiene, and living conditions. Only the indices for overall cleanliness and kitchen hygiene were significantly associated with diarrhoea. An increasing excess risk of hospitalization with severe diarrhoe...

Detection of Pneumocystis DNA in samples from patients suspected of bacterial pneumonia--a case-control study

DEFF Research Database (Denmark)

Helweg-Larsen, Jannik; Jensen, Jørgen Skov; Dohn, Birthe

2002-01-01

Pneumocystis jiroveci (formerly known as P. carinii f.sp. hominis) is an opportunistic fungus that causes Pneumocystis pneumonia (PCP) in immunocompromised individuals. Pneumocystis jiroveci can be detected by polymerase chain reaction (PCR). To investigate the clinical importance of a positive P...... Pneumocystis-PCR among HIV-uninfected patients suspected of bacterial pneumonia, a retrospective matched case-control study was conducted....

Case-control study of congenital malformations and occupational exposure to low-level ionizing radiation

International Nuclear Information System (INIS)

Sever, L.E.; Gilbert, E.S.; Hessol, N.A.; McIntyre, J.M.

1988-01-01

In a case-control study, the authors investigated the association of parental occupational exposure to low-level external whole-body penetrating ionizing radiation and risk of congenital malformations in their offspring. Cases and controls were ascertained from births in two counties in southeastern Washington State, where the Hanford Site has been a major employer. A unique feature of this study was the linking of quantitative individual measurement of external whole-body penetrating ionizing radiation exposure of employees at the Hanford Site, using personal dosimeters, and the disease outcome, congenital malformations. The study population included 672 malformation cases and 977 matched controls from births occurring from 1957 through 1980. Twelve specific malformation types were analyzed for evidence of association with employment of the parents at Hanford and with occupational exposure to ionizing radiation. Two defects, congenital dislocation of the hip and tracheoesophageal fistula, showed statistically significant associations with employment of the parents at Hanford, but not with parental radiation exposure. Neural tube defects showed a significant association with parental preconception exposure, on the basis of a small number of cases. Eleven other defects, including Down syndrome, for which an association with radiation was considered most likely, showed no evidence of such an association. When all malformations were analyzed as a group, there was no evidence of an association with employment of the parents at Hanford, but the relation of parental exposure to radiation before conception was in the positive direction (one-tailed p value between 0.05 and 0.10). Given the number of statistical tests conducted, some or all of the observed positive correlations are likely to represent false positive findings. 30 references

Candidate gene analysis of spontaneous preterm delivery: New insights from re-analysis of a case-control study using case-parent triads and control-mother dyads

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Myking Solveig

2011-12-01

Full Text Available Abstract Background Spontaneous preterm delivery (PTD has a multifactorial etiology with evidence of a genetic contribution to its pathogenesis. A number of candidate gene case-control studies have been performed on spontaneous PTD, but the results have been inconsistent, and do not fully assess the role of how two genotypes can impact outcome. To elucidate this latter point we re-analyzed data from a previously published case-control candidate gene study, using a case-parent triad design and a hybrid design combining case-parent triads and control-mother dyads. These methods offer a robust approach to genetic association studies for PTD compared to traditional case-control designs. Methods The study participants were obtained from the Norwegian Mother and Child Cohort Study (MoBa. A total of 196 case triads and 211 control dyads were selected for the analysis. A case-parent triad design as well as a hybrid design was used to analyze 1,326 SNPs from 159 candidate genes. We compared our results to those from a previous case-control study on the same samples. Haplotypes were analyzed using a sliding window of three SNPs and a pathway analysis was performed to gain biological insight into the pathophysiology of preterm delivery. Results The most consistent significant fetal gene across all analyses was COL5A2. The functionally similar COL5A1 was significant when combining fetal and maternal genotypes. PON1 was significant with analytical approaches for single locus association of fetal genes alone, but was possibly confounded by maternal effects. Focal adhesion (hsa04510, Cell Communication (hsa01430 and ECM receptor interaction (hsa04512 were the most constant significant pathways. Conclusion This study suggests a fetal association of COL5A2 and a combined fetal-maternal association of COL5A1 with spontaneous PTD. In addition, the pathway analysis implied interactions of genes affecting cell communication and extracellular matrix.

Lumbar lordosis and pars interarticularis fractures: a case-control study

International Nuclear Information System (INIS)

Bugg, William G.; Lewis, Mark; Juette, Arne; Cahir, John G.; Toms, Andoni P.

2012-01-01

The aim of this study is to examine the relationship between lumbar lordosis and pars interarticularis fractures. In this retrospective case-control study we compare the angle of lumbar lordosis and the angle of the S1 vertebral endplate (as a measure of pelvic tilt) in patients with bilateral L5 pars interarticularis fractures with age- and sex-matched control cases with normal MRI examinations of the lumbar spine. Twenty-nine cases of bilateral L5 pars interarticularis fractures with matched control-cases were identified on MRI (16 male, 13 female, age 9-63 years). The angle of lordosis was measured between the inferior L4 and superior S1 vertebral endplates on a standing lateral lumbar spine radiograph for both groups. The mean angle of lordosis about the L5 vertebra was 36.9 (SD = 6.5 ) in the pars interarticularis fracture group, and 30.1 (SD = 6.4 ) in the control group. The difference between the two groups was significant (mean difference 6.8 , Student's t test: P < 0.001). The mean angle of sacral tilt measured was 122.2 (SD = 10.16 ) for controls and 136.4 (SD = 10.86 ) for patients with pars defects. The difference in the means of 14.2 was statistically significantly different (P < 0.0001). Sacral tilt represented by a steeply angled superior endplate of S1 is associated with a significantly increased angle of lordosis, between L4 and S1, and pars fractures at L5. Steep angulation of the first sacral vertebral segment maybe the predisposing biomechanical factor that leads to pincer-like impingement of the pars interarticularis and then spondylolysis. (orig.)

Lumbar lordosis and pars interarticularis fractures: a case-control study

Energy Technology Data Exchange (ETDEWEB)

Bugg, William G; Lewis, Mark; Juette, Arne; Cahir, John G; Toms, Andoni P [Cotman Centre, Norwich Radiology Academy, Norwich, Norfolk (United Kingdom)

2012-07-15

The aim of this study is to examine the relationship between lumbar lordosis and pars interarticularis fractures. In this retrospective case-control study we compare the angle of lumbar lordosis and the angle of the S1 vertebral endplate (as a measure of pelvic tilt) in patients with bilateral L5 pars interarticularis fractures with age- and sex-matched control cases with normal MRI examinations of the lumbar spine. Twenty-nine cases of bilateral L5 pars interarticularis fractures with matched control-cases were identified on MRI (16 male, 13 female, age 9-63 years). The angle of lordosis was measured between the inferior L4 and superior S1 vertebral endplates on a standing lateral lumbar spine radiograph for both groups. The mean angle of lordosis about the L5 vertebra was 36.9 (SD = 6.5 ) in the pars interarticularis fracture group, and 30.1 (SD = 6.4 ) in the control group. The difference between the two groups was significant (mean difference 6.8 , Student's t test: P < 0.001). The mean angle of sacral tilt measured was 122.2 (SD = 10.16 ) for controls and 136.4 (SD = 10.86 ) for patients with pars defects. The difference in the means of 14.2 was statistically significantly different (P < 0.0001). Sacral tilt represented by a steeply angled superior endplate of S1 is associated with a significantly increased angle of lordosis, between L4 and S1, and pars fractures at L5. Steep angulation of the first sacral vertebral segment maybe the predisposing biomechanical factor that leads to pincer-like impingement of the pars interarticularis and then spondylolysis. (orig.)

Lumbar lordosis and pars interarticularis fractures: a case-control study

Energy Technology Data Exchange (ETDEWEB)

Bugg, William G.; Lewis, Mark; Juette, Arne; Cahir, John G.; Toms, Andoni P. [Cotman Centre, Norwich Radiology Academy, Norwich, Norfolk (United Kingdom)

2012-07-15

The aim of this study is to examine the relationship between lumbar lordosis and pars interarticularis fractures. In this retrospective case-control study we compare the angle of lumbar lordosis and the angle of the S1 vertebral endplate (as a measure of pelvic tilt) in patients with bilateral L5 pars interarticularis fractures with age- and sex-matched control cases with normal MRI examinations of the lumbar spine. Twenty-nine cases of bilateral L5 pars interarticularis fractures with matched control-cases were identified on MRI (16 male, 13 female, age 9-63 years). The angle of lordosis was measured between the inferior L4 and superior S1 vertebral endplates on a standing lateral lumbar spine radiograph for both groups. The mean angle of lordosis about the L5 vertebra was 36.9 (SD = 6.5 ) in the pars interarticularis fracture group, and 30.1 (SD = 6.4 ) in the control group. The difference between the two groups was significant (mean difference 6.8 , Student's t test: P < 0.001). The mean angle of sacral tilt measured was 122.2 (SD = 10.16 ) for controls and 136.4 (SD = 10.86 ) for patients with pars defects. The difference in the means of 14.2 was statistically significantly different (P < 0.0001). Sacral tilt represented by a steeply angled superior endplate of S1 is associated with a significantly increased angle of lordosis, between L4 and S1, and pars fractures at L5. Steep angulation of the first sacral vertebral segment maybe the predisposing biomechanical factor that leads to pincer-like impingement of the pars interarticularis and then spondylolysis. (orig.)

Neospora caninum versus Brucella spp. exposure among dairy cattle in Ethiopia: a case control study.

Science.gov (United States)

Asmare, Kassahun

2014-08-01

This case-control study aimed at assessing the relative association of Neospora caninum and Brucella species exposure with reproductive disorders. The study was carried out between October 2011 and June 2012 on 731 dairy cows sampled from 150 dairy farms in selected 17 conurbations of Ethiopia. Two hundred sixty-six of the cows were categorized as cases based on their history of abortion or stillbirth while the remaining 465 were controls. The presence of antibody to N. caninum was screened using indirect ELISA, while Brucella spp. exposure was assayed serially using Rose Bengal Plate Test and Complement Fixation Test. Exposure to N. caninum was more frequently observed among cases (23.8%) than controls (12.7%), while no significant difference (p > 0.05) was noted for Brucella exposure between the two groups. Moreover, the proportion of cows with disorders like retention of fetal membrane, endometritis and increased inter-calving period were significantly higher (p Brucella spp. exposure. However, neither N. caninum nor Brucella spp. could explain the majority (73.2%) of the reported abortions and stillbirths in cattle. Hence, this observation underscores the need for more intensive investigation on the identification of causes of the aforementioned disorders in dairy cattle of Ethiopia.

[Child abuse in Tlaxcala: a case-control study].

Science.gov (United States)

Herrada-Huidobro, A; Nazar-Beutelspacher, A; Cassaball-Núñez, M; Vega-Ramos, R; Nava-Cruz, C B

1992-01-01

A longitudinal, retrospective and descriptive study about child abuse was carried out in the Hospitals of the Tlaxcala Secretariat of Health, Mexico. The information was obtained from hospitalized children's charts between January first and November 30, 1991. The charts included were those belonging to zero to 14 year old children with injuries, poisoning, and II-III degrees of malnutrition. Four child-abuse criteria were established: physical, sexual, non organic malnutrition and mixed (physical and non organic malnutrition). Two control groups were defined. Different patterns were observed between accidental and non accidental injuries, malnutrition and poisoning among the case and the control groups. The study provides useful information for the integral diagnosis of child abuse in hospitalized children.

Tularaemia outbreaks in Sakarya, Turkey: case-control and environmental studies.

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Meric, M; Sayan, M; Dundar, D; Willke, A

2010-08-01

Tularaemia is an important zoonotic disease that leads to outbreaks. This study aimed to compare the epidemiological characteristics of two tularaemia outbreaks that occurred in the Sakarya region of Turkey, analyse the risk factors for the development of outbreaks and identify Francisella (F.) tularensis in the water samples. Two tularaemia outbreaks occurred in the Kocadongel village in 2005 and 2006. A field investigation and a case-control study with 47 cases and 47 healthy households were performed during the second outbreak. Clinical samples from the patients and filtrated water samples were analysed for F. tularensis via real-time polymerase chain reaction. From the two outbreaks, a total of 58 patients were diagnosed with oropharyngeal tularaemia based on their clinical and serological results. Both outbreaks occurred between the months of January and April, and the number of patients peaked in February. Logistic regression analysis revealed that the consumption of natural spring water was the only significant risk factor for tularaemia infection (odds ratio 3.5, confidence interval 1.23-10.07). F. tularensis was detected in eight clinical samples and in the filtrated natural spring water. This study is the first report of tularaemia from this region. The results show that both tularaemia outbreaks were related to the consumption of untreated natural spring water. To prevent waterborne tularaemia, community water supplies should be treated and checked periodically.

Prolonged outbreak of Serratia marcescens in Tartu University Hospital: a case-control study.

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Adamson, Vivika; Mitt, Piret; Pisarev, Heti; Metsvaht, Tuuli; Telling, Kaidi; Naaber, Paul; Maimets, Matti

2012-10-31

The aim of our study was to investigate and control an outbreak and identify risk factors for colonization and infection with Serratia marcescens in two departments in Tartu University Hospital. The retrospective case-control study was conducted from July 2005 to December 2006. Molecular typing by pulsed field gel electrophoresis was used to confirm the relatedness of Serratia marcescens strains. Samples from the environment and from the hands of personnel were cultured. The outbreak involved 210 patients, 61 (29%) developed an infection, among them 16 were invasive infections. Multivariate analysis identified gestational age, arterial catheter use and antibiotic treatment as independent risk factors for colonization and infection with Serratia marcescens. Molecular typing was performed on 83 Serratia marcescens strains, 81 of them were identical and 2 strains were different. Given the occasionally severe consequences of Serratia marcescens in infants, early implementation of aggressive infection control measures involving patients and mothers as well as the personnel is of utmost importance.

An outbreak of vancomycin-resistant Enterococcus faecium in an acute care pediatric hospital: Lessons from environmental screening and a case-control study

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Drews, Steven J; Richardson, Susan E; Wray, Rick; Freeman, Renee; Goldman, Carol; Streitenberger, Laurie; Stevens, Derek; Goia, Cristina; Kovach, Danuta; Brophy, Jason; Matlow, Anne G

2008-01-01

BACKGROUND The present study describes a vancomycin-resistant enterococci (VRE) outbreak investigation and a case-control study to identify risk factors for VRE acquisition in a tertiary care pediatric hospital. OBJECTIVE To report an outbreak investigation and a case-control study to identify risk factors for VRE colonization or infection in hospitalized children. METHODS Screening for VRE cases was performed by culture or polymerase chain reaction. A case-control study of VRE-colonized patients was undertaken. Environmental screening was performed using standard culture and susceptibility methods, with pulsed-field gel electrophoresis to determine relationships between VRE isolates. Statistical analysis was performed using SAS version 9.0 (SAS Institute Inc, USA). RESULTS Thirty-four VRE-positive cases were identified on 10 wards between February 28, 2005, and May 27, 2005. Pulsed-field gel electrophoresis analysis confirmed a single outbreak strain that was also isolated from a video game found on one affected ward. Multivariate analysis identified cephalosporin use as the major risk factor for VRE colonization. CONCLUSIONS In the present study outbreak, VRE colonization was significantly associated with cephalosporin use. Because shared recreational items and environmental surfaces may be colonized by VRE, they warrant particular attention in housekeeping protocols, particularly in pediatric institutions. PMID:19412380

Radiation exposure and central nervous system cancers: A case-control study among workers at two nuclear facilities

International Nuclear Information System (INIS)

Carpenter, A.V.; Flanders, W.D.; Frome, E.L.; Crawford-Brown, D.J.; Fry, S.A.

1987-03-01

A nested case-control study was conducted among workers employed between 1943 and 1977 at two nuclear facilities to investigate the possible association of primary malignant neoplasms of the central nervous system (CNS) with occupational exposure to ionizing radiation from external and internal sources. Eighty-nine white male and female workers, who according to the information on death certificates dies of primary CNS cancers, were identified as cases. Four matched controls were selected for each case. External radiation exposure data were available from film badge readings for individual workers, whereas radiation dose to lung from internally deposited radionuclides, mainly uranium, was estimated from area and personnel monitoring data and was used in analyses in lieu of the dose to the brain. Matched sets were included in the analyses only if information was available for the case and at least one of the corresponding controls. Thus, the analyses of external radiation included 27 cases and 90 matched controls, and 47 cases and 120 matched controls were analyzed for the effects of radiation from internally deposited uranium. No association was observed between deaths fron CNS cancers and occupational exposure to ionizing radiation from external or internal sources. However, due to the small number of monitored subjects and low doses, a weak association could not be ruled out. 43 refs., 1 fig., 15 tabs

Alcohol and Difficulty Conceiving in the SUN Cohort: A Nested Case-Control Study.

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Lopez-del Burgo, Cristina; Gea, Alfredo; de Irala, Jokin; Martínez-González, Miguel A; Chavarro, Jorge E; Toledo, Estefania

2015-07-27

The role of alcohol on fertility remains unclear. We aimed to investigate the association between alcohol and specific alcoholic beverages consumption and the risk of difficulty getting pregnant. We used a case-control study nested within the Seguimiento Universidad de Navarra (SUN) cohort, a prospective, dynamic and multipurpose cohort of 21,705 Spanish university graduates, followed biennially with mailed questionnaires. We identified 686 case-control pairs, matched for age and time in the cohort. Cases were women reporting difficulty getting pregnant. Controls did not consult due to difficulty conceiving and had at least one child during follow-up. After adjustment for potential confounders, we found no association between self-reported difficulty getting pregnant and the number of alcoholic beverages consumed per week, (Odds Ratio [OR] > 5 drinks/week vs. none = 1.04, 95% Confidence Interval [CI] = 0.72-1.51). No association between types of alcoholic beverage and difficulty conceiving (OR > 5 drinks of wine/week vs. none = 1.16, 95% CI = 0.72-1.88; OR > 5 drinks of beer/week vs. none = 1.06, 95% CI = 0.82-1.37; OR > 5 drinks of spirits/week vs. none = 1.24, 95% CI = 0.84-1.64) was observed. In conclusion, we found no association between alcohol intake and risk of consulting a physician due to difficulty conceiving. More studies are needed to clearly elucidate the effects of alcohol intake on women's fertility. In the meantime, recommendations about alcohol intake to couples trying to conceive have to be given cautiously.

Alcohol and Difficulty Conceiving in the SUN Cohort: A Nested Case-Control Study

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Cristina Lopez-del Burgo

2015-07-01

Full Text Available The role of alcohol on fertility remains unclear. We aimed to investigate the association between alcohol and specific alcoholic beverages consumption and the risk of difficulty getting pregnant. We used a case-control study nested within the Seguimiento Universidad de Navarra (SUN cohort, a prospective, dynamic and multipurpose cohort of 21,705 Spanish university graduates, followed biennially with mailed questionnaires. We identified 686 case-control pairs, matched for age and time in the cohort. Cases were women reporting difficulty getting pregnant. Controls did not consult due to difficulty conceiving and had at least one child during follow-up. After adjustment for potential confounders, we found no association between self-reported difficulty getting pregnant and the number of alcoholic beverages consumed per week, (Odds Ratio [OR] > 5 drinks/week vs. none = 1.04, 95% Confidence Interval [CI] = 0.72–1.51. No association between types of alcoholic beverage and difficulty conceiving (OR > 5 drinks of wine/week vs. none = 1.16, 95% CI = 0.72–1.88; OR > 5 drinks of beer/week vs. none = 1.06, 95% CI = 0.82–1.37; OR > 5 drinks of spirits/week vs. none = 1.24, 95% CI = 0.84–1.64 was observed. In conclusion, we found no association between alcohol intake and risk of consulting a physician due to difficulty conceiving. More studies are needed to clearly elucidate the effects of alcohol intake on women’s fertility. In the meantime, recommendations about alcohol intake to couples trying to conceive have to be given cautiously.

Dietary and lifestyle characteristics of colorectal cancer in Jordan: a case-control study.

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Arafa, Mostafa A; Waly, Mostafa I; Jriesat, Sahar; Al Khafajei, Ahmed; Sallam, Sunny

2011-01-01

We evaluated dietary pattern and lifestyle characteristics of patients with colorectal cancer (CRC) in Jordan. The case-control study included 220 recently diagnosed CRC cases and 220 age and gender matched healthy subjects as a control group. The participating CRC cases had lower dietary intake of fibre, folate, vitamin B12, β-carotene, vitamin C and selenium as compared to controls (P<0.05). The frequency of consumption of fruits and vegetables was also lower among CRC cases, while the frequency of consumption of red meat and saturated fat was higher and positively associated with CRC risk. Furthermore, family history for CRC played a positive role and the majority of CRC cases and controls had a low physical activity level. A sedentary lifestyle and a diet low in fruits and vegetables, and high in animal red meat and saturated fat, appeared associated with CRC among the studied Jordanian subjects. This is consistent with the reported CRC studies in developed nations indicating global causal effects for this tumour type.

Exploratory case-control study of brain tumors in adults

International Nuclear Information System (INIS)

Burch, J.D.; Craib, K.J.; Choi, B.C.; Miller, A.B.; Risch, H.A.; Howe, G.R.

1987-01-01

An exploratory study of brain tumors in adults was carried out using 215 cases diagnosed in Southern Ontario between 1979 and 1982, with an individually matched, hospital control series. Significantly elevated risks were observed for reported use of spring water, drinking of wine, and consumption of pickled fish, together with a significant protective effect for the regular consumption of any of several types of fruit. While these factors are consistent with a role for N-nitroso compounds in the etiology of these tumors, for several other factors related to this hypothesis, no association was observed. Occupation in the rubber industry was associated with a significant relative risk of 9.0, though no other occupational associations were seen. Two previously unreported associations were with smoking nonfilter cigarettes with a significant trend and with the use of hair dyes or sprays. The data do not support an association between physical head trauma requiring medical attention and risk of brain tumors and indicate that exposure to ionizing radiation and vinyl chloride monomer does not contribute any appreciable fraction of attributable risk in the population studied. The findings warrant further detailed investigation in future epidemiologic studies

Hygiene behaviour and hospitalized severe childhood diarrhoea: a case-control study.

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Baltazar, J C; Tiglao, T V; Tempongko, S B

1993-01-01

The relationship between personal and domestic hygiene behaviour and hospitalized childhood diarrhoea was examined in a case-control study of 356 cases and 357 controls from low-income families in metropolitan Manila. Indices of hygiene behaviour were defined for overall cleanliness, kitchen hygiene, and living conditions. Only the indices for overall cleanliness and kitchen hygiene were significantly associated with diarrhoea. An increasing excess risk of hospitalization with severe diarrhoea was noted as the ratings for standards of hygiene became lower, and this excess risk persisted even after controlling for confounding variables. The implications of our findings for the control of diarrhoeal disease are discussed.

Blastocystosis in patients with gastrointestinal symptoms: a case-control study.

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Cekin, Ayhan Hilmi; Cekin, Yesim; Adakan, Yesim; Tasdemir, Ezel; Koclar, Fatma Gulsun; Yolcular, Basak Oguz

2012-09-10

Blastocystosis is a frequent bowel disease. We planned to to evaluate the prevalence of Blastocystis spp. in patients who applied to the same internal medicine-gastroenterology clinic with or without gastrointestinal complaints to reveal the association of this parasite with diagnosed IBS and IBD. A total of 2334 patients with gastrointestinal symptoms composed the study group, which included 335 patients with diagnosed inflammatory bowel disease and 877 with irritable bowel syndrome. Patients without any gastrointestinal symptoms or disease (n = 192) composed the control group. Parasite presence was investigated by applying native-Lugol and formol ethyl acetate concentration to stool specimens, and trichrome staining method in suspicious cases. Blastocystis spp. was detected in 134 patients (5.74%) in the study group and 6 (3.12%) in the control group (p = 0.128). In the study group, Blastocystis spp. was detected at frequencies of 8.7% in ulcerative colitis (24/276), 6.78% in Crohn's disease (4/59), 5.82% in irritable bowel syndrome (51/877), and 4.9% in the remaining patients with gastrointestinal symptoms (55/1122). Blastocystis spp. was detected at a statistically significant ratio in the inflammatory bowel disease (odds ratio [OR] = 2.824; 95% confidence interval [CI]: 1.149-6.944; p = 0.019) and ulcerative colitis (OR = 2.952; 95% CI: 1.183-7.367; p = 0.016) patients within this group compared to controls. There were no statistically significant differences between the control group and Crohn's disease or irritable bowel syndrome patients in terms Blastocystis spp. frequency (p = 0.251, p = 0.133). Blastocystosis was more frequent in patients with inflammatory bowel disease, especially those with ulcerative colitis. Although symptomatic irritable bowel syndrome and Crohn's disease patients had higher rates of Blastocystis spp. infection, the differences were not significant when compared to controls.

Pilot case-control investigation of risk factors for hip fractures in the urban Indian population

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Malhotra Nidhi

2010-03-01

Full Text Available Abstract Background Despite the reported high prevalence of osteoporosis in India, there have been no previous studies examining the risk factors for hip fracture in the Indian population. Methods We carried out a case control investigation comprising 100 case subjects (57 women and 43 men admitted with a first hip fracture into one of three hospitals across New Delhi. The 100 controls were age and sex matched subjects who were either healthy visitors not related to the case patients or hospital staff. Information from all subjects was obtained through a questionnaire based interview. Results There was a significant increase in the number of cases of hip fracture with increasing age. There were significantly more women (57% than men (43%. Univariate analysis identified protective effects for increased activity, exercise, calcium and vitamin supplements, almonds, fish, paneer (cottage cheese, curd (plain yogurt, and milk. However, tea and other caffeinated beverages were significant risk factors. In women, hormone/estrogen therapy appeared to have a marginal protective effect. For all cases, decreased agility, visual impairment, long term medications, chronic illnesses increased the risk of hip fracture. The multivariate analysis confirmed a protective effect of increased activity and also showed a decrease in hip fracture risk with increasing body mass index (odds ratio (OR 0.024, 95% confidence interval (CI 0.006-0.10 & OR 0.81, 95% CI 0.68-0.97 respectively. Individuals who take calcium supplements have a decreased risk of hip fracture (OR 0.076; CI 0.017-0.340, as do individuals who eat fish (OR 0.094; CI 0.020-0.431, and those who eat paneer (OR 0.152; 0.031-0.741. Tea drinkers have a higher risk of hip fracture (OR 22.8; 95% CI 3.73-139.43. Difficulty in getting up from a chair also appears to be an important risk factor for hip fractures (OR 14.53; 95% CI 3.86-54.23. Conclusions In the urban Indian population, dietary calcium, vitamin D

Apolipoprotein E in Temporal Lobe Epilepsy: A Case-Control Study

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Kumar, Amit; Tripathi, Manjari; Pandey, Ravindra M.; Ramakrishnan, Lakshmy; Srinivas, M.; Luthra, Kalpana

2006-01-01

Purpose: To investigate the relationship of apolipoprotein E (apoE) genotype, plasma levels of apoE and lipids in temporal lobe epilepsy (TLE) patients in Asian Indians. Status of plasma levels of Apo E in epilepsy patients has not been reported till date. Methods: ApoE gene polymorphism was analyzed in 58 patients with temporal lobe epilepsy (TLE) and 57 age and sex approximated controls using Polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP). Levels of plasma apoE and lipids were measured using ELISA and enzymatic kits respectively. Results: The distribution of ApoE genotype in epilepsy patients and controls was comparable. Higher levels of plasma ApoE were observed in TLE patients as compared to controls (p = 0.0001). Individuals with plasma levels of apoE > 190 mg/L were at 20 times higher odds (95%CI = 2.46–163.34, p = 0.005), while those with levels of apoE between 150–190 mg/L were at 4.9 times higher odds (95% CI = 1.85–13.9, p = 0.001), to develop TLE. Conclusions: We have observed for the first time, high levels of plasma apoE in epilepsy patients. The findings of this case-control study suggest that apolipoprotein E may play an important role in epilepsy. PMID:17264404

Inverse association between yerba mate consumption and idiopathic Parkinson's disease. A case-control study.

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Gatto, Emilia Mabel; Melcon, Carlos; Parisi, Virginia L; Bartoloni, Leonardo; Gonzalez, Claudio D

2015-09-15

Yerba mate tea is a very common beverage in some countries of South America. We conducted a case-control study on an individual basis using hospital records to investigate the association between Parkinson's disease (PD) and yerba mate intake. A case was defined as an age of ≥ 40 years with ≥ 1 year of PD. Each case was individually matched by two controls. Exposure was measured by yerba mate consumption, coffee, tea, and alcohol intake and smoking status. The sample consisted of 223 PD patients (mean age 68 years and mean disease duration 7.3 years) and 406 controls. There was an inverse association between yerba mate "bombilla" consumption and PD (OR 0.64, 95% CI: 0.54-0.76, p=0.00001). A multivariate analysis with a logistic regression adjusted by sex, alcohol intake and smoking provided the following results: yerba mate (OR 0.63, 95% CI: 0.53-0.76), tea (OR 0.60, 95% CI: 0.42-0.86), coffee (OR 0.51, 95% CI: 0.35-0.73). We found an inverse association between yerba mate consumption and PD. These results led us to hypothesize that yerba mate may have a potential protective role in the development of PD. Copyright © 2015 Elsevier B.V. All rights reserved.

Maternal age and Alzheimer's disease: a collaborative re-analysis of case-control studies. EURODEM Risk Factors Research Group

NARCIS (Netherlands)

W.A. Rocca; C.M. van Duijn (Cornelia); D.G. Clayton (David); V. Chandra; L. Fratiglioni (Laura); A.B. Graves; A. Heyman; A.F. Jorm; E. Kokmen (Emre); K. Kondo; J.A. Mortimer; S.L. Shalat; H. Soininen; A. Hofman (Albert)

1991-01-01

textabstractTo investigate the possible association between Alzheimer's disease and late maternal age at index birth, we conducted a collaborative re-analysis of existing case-control data sets. Of the 11 studies participating in the EURODEM project, four were included in the analyses regarding

Increasing levels of free thyroxine as a risk factor for a first venous thrombosis: a case-control study

NARCIS (Netherlands)

van Zaane, Bregje; Squizzato, Alessandro; Huijgen, Roeland; van Zanten, Anton P.; Fliers, Eric; Cannegieter, Suzanne C.; Büller, Harry R.; Gerdes, Victor E. A.; Brandjes, Dees P. M.

2010-01-01

A hypercoagulable state exists in hyperthyroidism, but the association with venous thrombosis (VT) is not fully explored. We aimed to investigate VT risk for different plasma levels of thyroid hormones and thyroid antibodies. We used a case-control study on leg vein thrombosis conducted between

Dietary patterns, goitrogenic food, and thyroid cancer: a case-control study in French Polynesia.

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Cléro, Énora; Doyon, Françoise; Chungue, Vaïana; Rachédi, Frédérique; Boissin, Jean-Louis; Sebbag, Joseph; Shan, Larrys; Rubino, Carole; de Vathaire, Florent

2012-01-01

French Polynesia has one of the world's highest thyroid cancer incidence rates. A case-control study among native residents of French Polynesia included 229 cases of differentiated thyroid cancer diagnosed between 1979 and 2004, and 371 population controls. Dietary patterns and goitrogenic food consumption (cabbage, cassava) were analyzed. We used a factor analysis to identify dietary patterns and a conditional logistic regression analysis to investigate the association between dietary patterns or food items and thyroid cancer risk. Two distinct dietary patterns were identified: traditional Polynesian and Western. A nonsignificant inverse association was observed between the traditional Polynesian dietary pattern and thyroid cancer risk. The Western pattern was not associated with thyroid cancer risk. Cassava consumption was significantly associated with a decreased risk of thyroid cancer. In conclusion, a traditional Polynesian dietary pattern led to a weak reduced risk of thyroid cancer in French Polynesia. The protective effect of cassava on this cancer does not seem to be substantially different from that of cabbage, which was the main goitrogenic food studied to date.

Ethnic variations in severe maternal morbidity in the UK- a case control study.

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Manisha Nair

Full Text Available Previous studies showed a higher risk of maternal morbidity amongst black and other minority ethnic (BME groups, but were unable to investigate whether this excess risk was concentrated within specific BME groups in the UK. Our aim was to analyse the specific risks and to investigate reasons for any disparity.Unmatched case-control analysis using data from the United Kingdom Obstetric Surveillance System (UKOSS, February 2005-January 2013. Cases were 1,753 women who experienced severe morbidity during the peripartum period. Controls were 3,310 women who delivered immediately before the cases in the same hospital. Multivariable logistic regression modelling was used to adjust for known confounders and to understand their effects.Compared with white European women, the odds of severe maternal morbidity were 83% higher among black African women (adjusted odds ratio (aOR = 1.83; 95% Confidence Interval (CI = 1.39-2.40, 80% higher among black Caribbean (aOR = 1.80; 95% CI = 1.14-2.82, 74% higher in Bangladeshi (aOR = 1.74; 95% CI = 1.05-2.88, 56% higher in other non-whites (non-Asian (aOR = 1.56; 95% CI = 1.05-2.33 and 43% higher among Pakistani women (aOR = 1.43; 95% CI = 1.07-1.92. There was no evidence of substantial confounding. Anaemia in current pregnancy, previous pregnancy problems, inadequate utilisation of antenatal care, pre-existing medical conditions, parity>3, and being younger and older were independent risk factors but, the odds of severe maternal morbidity did not differ by socioeconomic status, between smokers and non-smokers or by BMI.This national study demonstrates an increased risk of severe maternal morbidity among women of ethnic minority backgrounds which could not be explained by known risk factors for severe maternal morbidity.

A case-control study of risk factors associated with scrub typhus infection in Beijing, China.

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Yanning Lyu

Full Text Available To investigate the risk factors of scrub typhus infection in Beijing, China, a case-control study was carried out. Cases (n = 56 were defined as persons who were diagnosed by PCR and serological method within three years. Three neighborhood control subjects were selected by matching for age and occupation. Living at the edge of the village, living in the houses near grassland, vegetable field or ditch, house yard without cement floor, piling weeds in the house or yard, all of these were risk factors for scrub typhus infection. Working in vegetable fields and hilly areas, and harvesting in autumn posed the highest risks, with odds ratios (ORs and 95% confidence intervals (CIs of 3.7 (1.1-11.9, 8.2 (1.4-49.5, and 17.2 (5.1-57.9, respectively. These results would be useful for the establishment of a detail control strategy for scrub typhus infection in Beijing, China.

Birth order and sibship size: evaluation of the role of selection bias in a case-control study of non-Hodgkin's lymphoma.

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Mensah, F K; Willett, E V; Simpson, J; Smith, A G; Roman, E

2007-09-15

Substantial heterogeneity has been observed among case-control studies investigating associations between non-Hodgkin's lymphoma and familial characteristics, such as birth order and sibship size. The potential role of selection bias in explaining such heterogeneity is considered within this study. Selection bias according to familial characteristics and socioeconomic status is investigated within a United Kingdom-based case-control study of non-Hodgkin's lymphoma diagnosed during 1998-2001. Reported distributions of birth order and maternal age are each compared with expected reference distributions derived using national birth statistics from the United Kingdom. A method is detailed in which yearly data are used to derive expected distributions, taking account of variability in birth statistics over time. Census data are used to reweight both the case and control study populations such that they are comparable with the general population with regard to socioeconomic status. The authors found little support for an association between non-Hodgkin's lymphoma and birth order or family size and little evidence for an influence of selection bias. However, the findings suggest that between-study heterogeneity could be explained by selection biases that influence the demographic characteristics of participants.

Distribution of ABO and Rh Blood Groups in Patients With Keratoconus: A Case-Control Study.

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Naderan, Mohammad; Rajabi, Mohammad Taher; Shoar, Saeed; Kamaleddin, Mohammad Amin; Naderan, Morteza; Rezagholizadeh, Farzaneh; Zolfaghari, Masoome; Pahlevani, Rozhin

2015-07-01

Association of keratoconus (KC) with genetic predisposition and environmental factors has been well documented. However, no single study has investigated the possible relationship between ABO and Rh blood groups and KC. A case-control study was designed in a university hospital enrolling 214 patients with KC in the case group and equal number of age- and sex-matched healthy subjects in the control group. Primary characteristics, ABO blood group, and Rh factors were compared between the two groups. Topographic findings of KC eyes and the severity of the diseases were investigated according to the distribution of the blood groups. Blood group O and Rh(+) phenotype were most frequent in both groups. There was no significant difference between the two groups in terms of ABO blood groups or Rh factors. Mean keratometery (K), central corneal thickness, thinnest corneal thickness, flat K, steep K, sphere and cylinder, spherical equivalent, and uncorrected visual acuity were all similar between ABO blood groups and Rh(+) and Rh(-) groups. However, the best spectacle-corrected visual acuity (BCVA) had the highest value in AB blood group (0.35 ± 0.22 logMAR, P=0.005). Moreover, the blood group AB revealed the highest frequency for grade 3 KC, followed by grades 1, 2, and 4 (P=0.003). We observed no significant excess of any particular blood group among KC cases compared with healthy subjects. Except BCVA, none of the keratometric or topographic findings was significantly different between blood groups.

On the Analysis of Case-Control Studies in Cluster-correlated Data Settings.

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Haneuse, Sebastien; Rivera-Rodriguez, Claudia

2018-01-01

In resource-limited settings, long-term evaluation of national antiretroviral treatment (ART) programs often relies on aggregated data, the analysis of which may be subject to ecological bias. As researchers and policy makers consider evaluating individual-level outcomes such as treatment adherence or mortality, the well-known case-control design is appealing in that it provides efficiency gains over random sampling. In the context that motivates this article, valid estimation and inference requires acknowledging any clustering, although, to our knowledge, no statistical methods have been published for the analysis of case-control data for which the underlying population exhibits clustering. Furthermore, in the specific context of an ongoing collaboration in Malawi, rather than performing case-control sampling across all clinics, case-control sampling within clinics has been suggested as a more practical strategy. To our knowledge, although similar outcome-dependent sampling schemes have been described in the literature, a case-control design specific to correlated data settings is new. In this article, we describe this design, discuss balanced versus unbalanced sampling techniques, and provide a general approach to analyzing case-control studies in cluster-correlated settings based on inverse probability-weighted generalized estimating equations. Inference is based on a robust sandwich estimator with correlation parameters estimated to ensure appropriate accounting of the outcome-dependent sampling scheme. We conduct comprehensive simulations, based in part on real data on a sample of N = 78,155 program registrants in Malawi between 2005 and 2007, to evaluate small-sample operating characteristics and potential trade-offs associated with standard case-control sampling or when case-control sampling is performed within clusters.

The Relationship between Maternal Diseases during Pregnancy and Low Birth Weight: a Nested Case-Control Study in Rural Areas of Kurdistan Province (West of Iran

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Ghobad Moradi

2017-08-01

Full Text Available Background: Low birth weight (LBW is considered as one of the important health indicators in evaluating prenatal care as well as determining scale of infants' health in the society. The study aimed to investigate maternal diseases during pregnancy and its impact on LBW in rural areas of Kurdistan province, Iran. Materials and Methods: This study was conducted in nested case-control study method in rural areas of Kurdistan province- Iran in 2015-2016. In this study, 182 infants less than 2,500gr as case and 364 infants weighing 2,500 g and more as control were entered the study. Information about case and control groups was extracted by investigating records of pregnant women care. Data was analyzed using software Stata-12 with point and interval estimation of odds ratio (OR using conditional logistic regression. Results: The results of single-variable analysis of conditional logistic regression showed that there is a statistical relationship between blood pressure during pregnancy, iron deficiency anemia, mother's thyroid problems, oral and dental problems, and history of bleeding during pregnancy in case and control groups (P

Risk Factors Profile of Shoulder Dystocia in Oman: A Case Control Study

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Al-Khaduri, Maha M.; Abudraz, Rania Mohammed; Al-Farsi, Yahya M.

2014-01-01

Objective This study aimed to assess the risk factor profile of shoulder dystocia and associated neonatal complications in Oman, a developing Arab country. Methods A retrospective case-control study was conducted among 111 cases with dystocia and 111 controls, identified during 1994-2006 period in a tertiary care hospital in Oman. Controls were randomly selected among women who did not have dystocia, and were matched to cases on the day of delivery. Data related to potential risk factors, delivery, and obstetric complications were collected. Results Dystocia was significantly associated with older maternal age, higher parity, larger BMI, diabetes, and previous record of dystocia. In addition, dystocia was associated more with vacuum and forceps deliveries. Routine traction (51%) was the most used manoeuvre. Among dystocia cases, 13% were associated with fetal complications of which Erb’s Palsy was the most prevalent (79%). Conclusion Our finding of significant associations with risk factors lays out the ground to develop a predictability index for shoulder dystocia, which would help in making it preventable. Further p rospective studies are required to confirm the obtained results. PMID:25337307

Risk Factors Profile of Shoulder Dystocia in Oman: A Case Control Study

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Maha M. Al-Khaduri

2014-09-01

Full Text Available Objective: This study aimed to assess the risk factor profile of shoulder dystocia and associated neonatal complications in Oman, a developing Arab country. Methods: A retrospective case-control study was conducted among 111 cases with dystocia and 111 controls, identified during 1994-2006 period in a tertiary care hospital in Oman. Controls were randomly selected among women who did not have dystocia, and were matched to cases on the day of delivery. Data related to potential risk factors, delivery, and obstetric complications were collected. Results: Dystocia was significantly associated with older maternal age, higher parity, larger BMI, diabetes, and previous record of dystocia. In addition, dystocia was associated more with vacuum and forceps deliveries. Routine traction (51% was the most used manoeuvre. Among dystocia cases, 13% were associated with fetal complications of which Erb’s Palsy was the most prevalent (79%. Conclusion: Our finding of significant associations with risk factors lays out the ground to develop a predictability index for shoulder dystocia, which would help in making it preventable. Further prospective studies are required to confirm the obtained results.

Hyperthyroidism association with SLE, lessons from real-life data--A case-control study.

Science.gov (United States)

Watad, Abdulla; Cohen, Arnon D; Comaneshter, Doron; Tekes-Manova, Dorit; Amital, Howard

2016-01-01

Despite the frequently encountered association between thyroid disease and systemic lupus erythematosus (SLE) is well known, it is of surprise that only several reports compromised of small population size support this observation. To investigate the association of comorbid SLE and hyperthyroidism. Using the database of the largest health maintenance organization (HMO) in Israel, the Clalit Health Services, we searched for the co-existence of SLE and hyperthyroidism. Patients with SLE were compared with age- and sex-matched controls regarding the prevalence of hyperthyroidism in a case-control study. Chi-square and t-tests were used for univariate analysis and a logistic regression model was used for multivariate analysis. The study included 5018 patients with SLE and 25,090 age- and sex- matched controls. The prevalence of hyperthyroidism in patients with SLE was increased compared with the prevalence in controls (2.59% and 0.91%, respectively, p hyperthyroidism (odds ratio 2.52, 95% confidence interval 2.028-3.137). Patients with SLE have a greater prevalence of hyperthyroidism than matched controls. Therefore, physicians treating patients with SLE should be aware of this possibility of this thyroid dysfunction.

A case-control study of risk of leukaemia in relation to mobile phone use.

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Cooke, R; Laing, S; Swerdlow, A J

2010-11-23

Mobile phone use is now ubiquitous, and scientific reviews have recommended research into its relation to leukaemia risk, but no large studies have been conducted. In a case-control study in South East England to investigate the relation of acute and non-lymphocytic leukaemia risk to mobile phone use, 806 cases with leukaemia incident 2003-2009 at ages 18-59 years (50% of those identified as eligible) and 585 non-blood relatives as controls (provided by 392 cases) were interviewed about mobile phone use and other potentially aetiological variables. No association was found between regular mobile phone use and risk of leukaemia (odds ratio (OR)=1.06, 95% confidence interval (CI)=0.76, 1.46). Analyses of risk in relation to years since first use, lifetime years of use, cumulative number of calls and cumulative hours of use produced no significantly raised risks, and there was no evidence of any trends. A non-significantly raised risk was found in people who first used a phone 15 or more years ago (OR=1.87, 95% CI=0.96, 3.63). Separate analyses of analogue and digital phone use and leukaemia subtype produced similar results to those overall. This study suggests that use of mobile phones does not increase leukaemia risk, although the possibility of an effect after long-term use, while biologically unlikely, remains open.

Analysis of single nucleotide polymorphisms in case-control studies.

Science.gov (United States)

Li, Yonghong; Shiffman, Dov; Oberbauer, Rainer

2011-01-01

Single nucleotide polymorphisms (SNPs) are the most common type of genetic variants in the human genome. SNPs are known to modify susceptibility to complex diseases. We describe and discuss methods used to identify SNPs associated with disease in case-control studies. An outline on study population selection, sample collection and genotyping platforms is presented, complemented by SNP selection, data preprocessing and analysis.

Shrinkage Estimators for Robust and Efficient Inference in Haplotype-Based Case-Control Studies

KAUST Repository

Chen, Yi-Hau; Chatterjee, Nilanjan; Carroll, Raymond J.

2009-01-01

Case-control association studies often aim to investigate the role of genes and gene-environment interactions in terms of the underlying haplotypes (i.e., the combinations of alleles at multiple genetic loci along chromosomal regions). The goal of this article is to develop robust but efficient approaches to the estimation of disease odds-ratio parameters associated with haplotypes and haplotype-environment interactions. We consider "shrinkage" estimation techniques that can adaptively relax the model assumptions of Hardy-Weinberg-Equilibrium and gene-environment independence required by recently proposed efficient "retrospective" methods. Our proposal involves first development of a novel retrospective approach to the analysis of case-control data, one that is robust to the nature of the gene-environment distribution in the underlying population. Next, it involves shrinkage of the robust retrospective estimator toward a more precise, but model-dependent, retrospective estimator using novel empirical Bayes and penalized regression techniques. Methods for variance estimation are proposed based on asymptotic theories. Simulations and two data examples illustrate both the robustness and efficiency of the proposed methods.

Shrinkage Estimators for Robust and Efficient Inference in Haplotype-Based Case-Control Studies

KAUST Repository

Chen, Yi-Hau

2009-03-01

Case-control association studies often aim to investigate the role of genes and gene-environment interactions in terms of the underlying haplotypes (i.e., the combinations of alleles at multiple genetic loci along chromosomal regions). The goal of this article is to develop robust but efficient approaches to the estimation of disease odds-ratio parameters associated with haplotypes and haplotype-environment interactions. We consider "shrinkage" estimation techniques that can adaptively relax the model assumptions of Hardy-Weinberg-Equilibrium and gene-environment independence required by recently proposed efficient "retrospective" methods. Our proposal involves first development of a novel retrospective approach to the analysis of case-control data, one that is robust to the nature of the gene-environment distribution in the underlying population. Next, it involves shrinkage of the robust retrospective estimator toward a more precise, but model-dependent, retrospective estimator using novel empirical Bayes and penalized regression techniques. Methods for variance estimation are proposed based on asymptotic theories. Simulations and two data examples illustrate both the robustness and efficiency of the proposed methods.

Low dose irradiation and risk of leukaemia: A case-control study

International Nuclear Information System (INIS)

Chobanova, N.; Bayrakova, A.

1997-01-01

The effect of low dose irradiation (medical X-ray diagnostic) on the developing of leukaemias in adults is investigated. The influence of non-radiation agents (occupational exposure to chemical carcinogens, past viral infections, family aggregations) to leukaemias are considered also. During this retrospective study 228 patients have been examined with the following diagnosis: acute myeloid leukaemia, chronic myelogenous leukaemias, myelodisplastic syndrome and non-Hodgkin lymphoma (diagnosed between 1991-1993). Each case has been matched with two controls. Statistically significant increase has been found in the risk of developing leukaemias after X-ray diagnostic irradiation (OR = 1.98, 95% CI = 1.14 ./. 3.46). Exposure to chemical agents is also associated with significant increase in the risk (OR = 1.98, 95% CI = 1.25 ./. 2.86). (author)

Body Weight and Breast Cancer: Nested Case-Control Study in Southern Brazil.

Science.gov (United States)

Kops, Natália Luiza; Bessel, Marina; Caleffi, Maira; Ribeiro, Rodrigo Antonini; Wendland, Eliana Marcia

2018-04-28

Current studies have shown that fast weight gain may be more important than body mass index on the incidence of breast cancer. The aim of this study was to evaluate the association between body weight and breast cancer. This was a case-control study nested in a cohort of a breast cancer mammography screening program in Southern Brazil. A trained investigator administered a standardized interview to collect sociodemographic and clinical data, and body weight history (weight at menarche, at marriage, at first and last pregnancy, and at menopause). Current anthropometric measurements were also made. Fifty-seven women with cancer (66.7% postmenopausal) and 159 controls were included. Current age (60.3 ± 10.4 vs. 55.8 ± 8.4 years, P weight at different stages of life. Women with social vulnerability recruited at a mammography screening program in Southern Brazil showed a large weight gain during life, but no significant differences were found in body weight between women with or without breast cancer. Copyright © 2018 Elsevier Inc. All rights reserved.

Prevalence of Periodontitis in Patients with Established Rheumatoid Arthritis: A Swedish Population Based Case-Control Study

Science.gov (United States)

Eriksson, Kaja; Nise, Lena; Kats, Anna; Luttropp, Elin; Catrina, Anca Irinel; Askling, Johan; Jansson, Leif; Alfredsson, Lars; Klareskog, Lars; Lundberg, Karin; Yucel-Lindberg, Tülay

2016-01-01

Introduction The possible hypothesis of a link between periodontitis and rheumatoid arthritis (RA), specifically anti-citrullinated protein antibody (ACPA) positive RA, prompted us to investigate the prevalence of periodontitis in the Swedish Epidemiological Investigation of RA (EIRA), a well-characterised population-based RA case-control cohort. Methods Periodontal status of 2,740 RA cases and 3,942 matched controls was retrieved through linking EIRA with the National Dental Health Registry (DHR), where dental diagnostic- and treatment codes on the adult Swedish population have been registered. Dental records from 100 cases and controls were reviewed to validate the periodontal diagnostic codes in DHR. Results The reviewed dental records confirmed 90% of the periodontitis diagnoses in DHR among RA cases, and 88% among controls. We found the positive predictive value of periodontitis diagnoses in the DHR to be 89% (95% CI 78 to 95%) with a sensitivity of 77% (95% CI: 65 to 86%). In total, 86% of EIRA participants were identified in DHR. The risk for periodontitis increased by age and current smoking status in both cases as well as controls. No significant differences in prevalence of periodontal disease in terms of gingivitis, periodontitis, peri-implantitis or increased risk for periodontitis or peri-implantitis were observed between RA cases and controls. In addition, there was no difference on the basis of seropositivity, ACPA or rheumatoid factor (RF), among patients with RA. Conclusions Our data verify that smoking and ageing are risk factors for periodontitis, both in RA and controls. We found no evidence of an increased prevalence of periodontitis in patients with established RA compared to healthy controls, and no differences based on ACPA or RF status among RA subjects. PMID:27203435

The use of the bootstrap in the analysis of case-control studies with missing data

DEFF Research Database (Denmark)

Siersma, Volkert Dirk; Johansen, Christoffer

2004-01-01

nonparametric bootstrap, bootstrap confidence intervals, missing values, multiple imputation, matched case-control study......nonparametric bootstrap, bootstrap confidence intervals, missing values, multiple imputation, matched case-control study...

Radon and Lung Cancer Case-Control Study in Middle Ural

International Nuclear Information System (INIS)

Kirdin, I.A.; Lezhnin, V.L.; Yarmoshenko, I.V.; Ekidin, A.

2001-01-01

Full text: The pilot phase of radon and lung cancer case-control study has been performed in Karpinsk and Pervouralsk towns of Middle Ural region of Russia. The case group consists of 341 persons with lung cancer and living in that towns at least five previous years. The lung cancer diagnoses were carefully verified by instrumental techniques and 70% of its were morphologically validated. The persons for the control group (448) were chosen from the population living in that towns at least five years taking into account the age and sex. The special epidemiological questionnaire was developed which includes the items by the groups of factors as follow: clinical data, social factors, chronic lung diseases, life habit, tobacco smoking, alcohol drinking, diet preference etc. The epidemiological questionnaires were fulfilled for each member of case and control groups. Radon gas concentration and thoron equilibrium equivalent concentration measurements had been performed using nuclear track detectors and grab sampling accordingly in the dwellings of case and control groups members. By preliminary estimation the odds ratios are 1, 0.91, 1.2, 1.1 in the ranges of radon and thoron equilibrium equivalent concentration 0-6, 3-13, 13-36 and 36-370 Bq/m 3 respectively. The deeper and more rigorous analysis as well as different independent approaches will be discussed in the paper.(author)

High risk human papillomavirus in the periodontium : A case control study.

Science.gov (United States)

Shipilova, Anna; Dayakar, Manjunath Mundoor; Gupta, Dinesh

2017-01-01

Human papilloma viruses (HPVs) are small DNA viruses that have been identified in periodontal pocket as well as gingival sulcus. High risk HPVs are also associated with a subset of head and neck carcinomas. It is thought that the periodontium could be a reservoir for HPV. 1. Detection of Human Papilloma virus (HPV) in periodontal pocket as well as gingival of patients having localized chronic periodontitis and gingival sulcus of periodontally healthy subjects. 2. Quantitative estimation of E6 and E7 mRNA in subjects showing presence of HPV3. To assess whether periodontal pocket is a reservoir for HPV. This case-control study included 30 subjects with localized chronic Periodontitis (cases) and 30 periodontally healthy subjects (controls). Two samples were taken from cases, one from periodontal pocket and one from gingival sulcus and one sample was taken from controls. Samples were collected in the form of pocket scrapings and gingival sulcus scrapings from cases and controls respectively. These samples were sent in storage media for identification and estimation of E6/E7 mRNA of HPV using in situ hybridization and flow cytometry. Statistical analysis was done by using, mean, percentage and Chi Square test. A statistical package SPSS version 13.0 was used to analyze the data. P value oral cancer, periodontitis and HPV. However prospective studies are required to further explore this link.

Characteristics and prognosis of pneumococcal endocarditis: a case-control study.

Science.gov (United States)

Daudin, M; Tattevin, P; Lelong, B; Flecher, E; Lavoué, S; Piau, C; Ingels, A; Chapron, A; Daubert, J-C; Revest, M

2016-06-01

Case series have suggested that pneumococcal endocarditis is a rare disease, mostly reported in patients with co-morbidities but no underlying valve disease, with a rapid progression to heart failure, and high mortality. We performed a case-control study of 28 patients with pneumococcal endocarditis (cases), and 56 patients with non-pneumococcal endocarditis (controls), not matched for sex and age, during the years 1991-2013, in one referral centre. Alcoholism (39.3% versus 10.7%; p endocarditis. Cardiac surgery was required in 64.3% of patients with pneumococcal endocarditis, much earlier than in patients with non-pneumococcal endocarditis (mean time from symptom onset, 14.1 ± 18.2 versus 69.0 ± 61.1 days). In-hospital mortality rates were similar (7.1% versus 12.5%). Streptococcus pneumoniae causes rapidly progressive endocarditis requiring life-saving early cardiac surgery in most cases. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Heat and nuclear radiation as risk factors for male infertility: results of a French case-control study

International Nuclear Information System (INIS)

Thonneau, P.F.; Rachou, E.; Ducot, B.; Multigner, L.; Velez de la Calle, J.P.; Le Martelot, M.T.

1998-01-01

Very few studies have investigated the possible effects of environmental radiation and heat exposure on male reproductive function. We conducted a case control study to evaluate the various infertility risk factors in the military population of the french town of Brest to investigate an apparently high incidence of infertility in couples in which the man may have been exposed to occupational nuclear radiation. These findings suggest that in addition to well known medical factors, 'potential' exposure to heat or nuclear radiation could also be risk factors for infertility. (N.C.)

Putative periodontopathic bacteria and herpesviruses in pregnant women: a case-control study

OpenAIRE

Lu, Haixia; Zhu, Ce; Li, Fei; Xu, Wei; Tao, Danying; Feng, Xiping

2016-01-01

Little is known about herpesvirus and putative periodontopathic bacteria in maternal chronic periodontitis. The present case-control study aimed to explore the potential relationship between putative periodontopathic bacteria and herpesviruses in maternal chronic periodontitis.Saliva samples were collected from 36 pregnant women with chronic periodontitis (cases) and 36 pregnant women with healthy periodontal status (controls). Six putative periodontopathic bacteria (Porphyromonas gingivalis ...

Lung and bladder cancer among Danish urban bus drivers and tramway employees: a nested case-control study.

Science.gov (United States)

Soll-Johanning, Helle; Bach, Elsa; Jensen, Steen S

2003-02-01

The combustion of fossil fuels produces small amounts of mutagenic and carcinogenic compounds. We investigated the association between employment and lung and bladder cancer in Danish bus drivers and tramway employees. We carried out a nested case-control study of 153 lung and 84 bladder cancer cases, and 606 controls sampled in a cohort of 18 174 bus drivers or tramway employees employed in Copenhagen during the period 1900-1994. The cases and controls or their next of kin were interviewed about smoking, along with occupational and residential history. An exposure index based on which bus routes the bus drivers had mainly been driving was established. Relative risks (RRs) were estimated by conditional logistic regression. The analysis showed decreasing risk for lung cancer with increasing years of employment as a bus driver (RR = 0.97 for each added year, 95% confidence interval = 0.96-0.99). The air pollution index based on main bus for the bus drivers showed no positive correlation with risk.

Numerical Investigations of Dynamic Stall Control

Directory of Open Access Journals (Sweden)

Florin FRUNZULICA

2014-04-01

Full Text Available In this paper we investigated numerically the dynamic stall phenomenon and the possibilities to control it, with application to vertical axis wind turbines (for urban users. The Phenomenon appear at low tip speed ratio (TSR<4 and it has a great impact on structural integrity of the wind turbine and power performances. For this reason we performed a computational study of dynamic stall around NACA 0012 airfoil in pitching motion at relative low Reynolds number (105. Also, we performed the same analysis for four flow control methods: two passive (Gurney flap and slot and two active (blowing jet on the rounded trailing edge and synthetic jet periodically activated. The Results are compared to those of an existing experimental case test.

External adjustment of unmeasured confounders in a case-control study of benzodiazepine use and cancer risk

DEFF Research Database (Denmark)

Thygesen, Lau Caspar; Pottegård, Anton; Ersbøll, Annette Kjaer

2017-01-01

AIMS: Previous studies have reported diverging results on the association between benzodiazepine use and cancer risk. METHODS: We investigated this association in a matched case-control study including incident cancer cases during 2002-2009 in the Danish Cancer Registry (n = 94 923) and age......% confidence interval 1.00-1.19) and for smoking-related cancers from 1.20 to 1.10 (95% confidence interval 1.00-1.21). CONCLUSION: We conclude that the increased risk observed in the solely register-based study could partly be attributed to unmeasured confounding....... PSs were used: The error-prone PS using register-based confounders and the calibrated PS based on both register- and survey-based confounders, retrieved from the Health Interview Survey. RESULTS: Register-based data showed that cancer cases had more diagnoses, higher comorbidity score and more co...

Adaptation of Chain Event Graphs for use with Case-Control Studies in Epidemiology.

Science.gov (United States)

Keeble, Claire; Thwaites, Peter Adam; Barber, Stuart; Law, Graham Richard; Baxter, Paul David

2017-09-26

Case-control studies are used in epidemiology to try to uncover the causes of diseases, but are a retrospective study design known to suffer from non-participation and recall bias, which may explain their decreased popularity in recent years. Traditional analyses report usually only the odds ratio for given exposures and the binary disease status. Chain event graphs are a graphical representation of a statistical model derived from event trees which have been developed in artificial intelligence and statistics, and only recently introduced to the epidemiology literature. They are a modern Bayesian technique which enable prior knowledge to be incorporated into the data analysis using the agglomerative hierarchical clustering algorithm, used to form a suitable chain event graph. Additionally, they can account for missing data and be used to explore missingness mechanisms. Here we adapt the chain event graph framework to suit scenarios often encountered in case-control studies, to strengthen this study design which is time and financially efficient. We demonstrate eight adaptations to the graphs, which consist of two suitable for full case-control study analysis, four which can be used in interim analyses to explore biases, and two which aim to improve the ease and accuracy of analyses. The adaptations are illustrated with complete, reproducible, fully-interpreted examples, including the event tree and chain event graph. Chain event graphs are used here for the first time to summarise non-participation, data collection techniques, data reliability, and disease severity in case-control studies. We demonstrate how these features of a case-control study can be incorporated into the analysis to provide further insight, which can help to identify potential biases and lead to more accurate study results.

Association between zolpidem use and glaucoma risk: a Taiwanese population-based case-control study.

Science.gov (United States)

Ho, Yi-Hao; Chang, Yue-Cune; Huang, Wei-Cheng; Chen, Hsin-Yi; Lin, Che-Chen; Sung, Fung-Chang

2015-01-01

To date, the relationship between zolpidem use and subsequent risk of glaucoma in a Taiwanese population has not been assessed. We used data from the National Health Insurance system to investigate whether zolpidem use was related to glaucoma risk. A 1:4 matched case-control study was conducted. The cases were patients newly diagnosed with glaucoma from 2001 to 2010. The controls were randomly selected non-glaucoma subjects matched by sex and age (± 5 years). Zolpidem exposure and/or the average dosage of zolpidem used (mg/year) were evaluated. Medical comorbidities were considered as confounding factors. Multiple logistic regression models were used to evaluate the potential risk of zolpidem exposure on glaucoma with/without adjustment for the effects of confounding variables. The exposure rate of zolpidem use in the glaucoma group was significantly higher than that of the control group (2.8% vs. 2.0%, P zolpidem use vs. those without was 1.19 (95% confidence interval [CI], 1.02-1.38). Compared to non-zolpidem users, zolpidem users with an average dose of more than 200 mg/year had significantly increased risk of glaucoma (OR 1.31, 95% CI 1.03-1.68). This study suggests that the use of zolpidem might increase the risk of subsequent glaucoma. Further confirmatory studies are recommended to clarify this important issue.

Use of methimazole and risk of acute pancreatitis: A case-control study in Taiwan.

Science.gov (United States)

Lai, Shih-Wei; Lin, Cheng-Li; Liao, Kuan-Fu

2016-01-01

Some cases of acute pancreatitis have been reported to be associated with use of methimazole. The aim of this study was to investigate the relationship between use of methimazole and risk of acute pancreatitis on the basis of a systematic analysis. This was a population-based case-control study analyzing the database of the Taiwan National Health Insurance Program. There were 5764 individuals aged 20-84 years with a first attack of acute pancreatitis from 1998 to 2011 as the cases and 23,056 randomly selected sex- and age-matched individuals without acute pancreatitis as the controls. Use of methimazole was categorized as "never use" and "ever use." We estimated the relative risk of acute pancreatitis associated with the use of methimazole by calculating the odds ratio (OR) with 95% confidence interval (CI) using a multivariable logistic regression model. After adjustment for confounding factors, the OR of acute pancreatitis was 0.91 in individuals with ever use of methimazole, when compared with individuals with never use of methimazole (95% CI, 0.60-1.38). Unlike methimazole use, alcohol-related disease, biliary stone, cardiovascular disease, chronic obstructive pulmonary disease, diabetes mellitus, hepatitis B, hepatitis C, and hypertriglyceridemia were factors significantly associated with acute pancreatitis. Our study does not detect a substantial association between the use of methimazole and risk of acute pancreatitis on the basis of systematic analysis. There appears to be a discrepancy between case reports and our systematic analysis about the association between the use of methimazole and risk of acute pancreatitis.

Mental illness, poverty and stigma in India: a case-control study.

Science.gov (United States)

Trani, Jean-Francois; Bakhshi, Parul; Kuhlberg, Jill; Narayanan, Sreelatha S; Venkataraman, Hemalatha; Mishra, Nagendra N; Groce, Nora E; Jadhav, Sushrut; Deshpande, Smita

2015-02-23

To assess the effect of experienced stigma on depth of multidimensional poverty of persons with severe mental illness (PSMI) in Delhi, India, controlling for gender, age and caste. Matching case (hospital)-control (population) study. University Hospital (cases) and National Capital Region (controls), India. A case-control study was conducted from November 2011 to June 2012. 647 cases diagnosed with schizophrenia or affective disorders were recruited and 647 individuals of same age, sex and location of residence were matched as controls at a ratio of 1:2:1. Individuals who refused consent or provided incomplete interview were excluded. Higher risk of poverty due to stigma among PSMI. 38.5% of PSMI compared with 22.2% of controls were found poor on six dimensions or more. The difference in multidimensional poverty index was 69% between groups with employment and income of the main contributors. Multidimensional poverty was strongly associated with stigma (OR 2.60, 95% CI 1.27 to 5.31), scheduled castes/scheduled tribes/other backward castes (2.39, 1.39 to 4.08), mental illness (2.07, 1.25 to 3.41) and female gender (1.87, 1.36 to 2.58). A significant interaction between stigma, mental illness and gender or caste indicates female PSMI or PSMI from 'lower castes' were more likely to be poor due to stigma than male controls (ppoverty linked to SMI are pervasive and intertwined. In particular for low caste and women, it is a strong predictor of poverty. Exclusion from employment linked to negative attitudes and lack of income are the highest contributors to multidimensional poverty, increasing the burden for the family. Mental health professionals need to be aware of and address these issues. 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.

Importance of Internal Audit and Internal Control in an organization - Case Study

OpenAIRE

Bubilek, Olga

2017-01-01

This research is a descriptive case study of a company. It presents concepts of the internal audit and internal control based on an example of a Finnish company. The research examines the role and importance that internal audit and internal controls have in an organization. The main research question is “What is the role and importance of internal audit and internal control in an organization” Additional sub-questions relating to the case company that will allow for better understanding of...

Nutritional variables and work-related accidents: a case-control study.

Science.gov (United States)

de Medeiros, M A T; Zangirolani, Lia Thieme Oikawa; Cordeiro, Ricardo Carlos; da Costa, Proença Rossana Pacheco; Diez-Garcia, Rosa Wanda

2014-01-01

Nutritional aspects are important for the prevention of diseases and disorders, and few studies have focused on the relationship between risk of work injury and nutritional variables. This study aimed to verify whether nutritional variables constitute risk factors for work-related accidents. 1,422 industrial workers (600 cases plus 822 controls). A case-control study was carried out in an industrial city in south-east Brazil. A multiple logistic regression model was adjusted using work-related accidents as the response variable and nutritional variables as predictors. The associations were assessed by Odds Ratio (OR), with a p-value work-related accidents were (a) attending formal education for an above average number of years (OR=0.91, pwork-related accidents. This indicates the need, during the formulation of policies for these kinds of government benefits, to include nutrition aspects in order to minimize work-related accidents risks.

Comparison of two control groups for estimation of oral cholera vaccine effectiveness using a case-control study design.

Science.gov (United States)

Franke, Molly F; Jerome, J Gregory; Matias, Wilfredo R; Ternier, Ralph; Hilaire, Isabelle J; Harris, Jason B; Ivers, Louise C

2017-10-13

Case-control studies to quantify oral cholera vaccine effectiveness (VE) often rely on neighbors without diarrhea as community controls. Test-negative controls can be easily recruited and may minimize bias due to differential health-seeking behavior and recall. We compared VE estimates derived from community and test-negative controls and conducted bias-indicator analyses to assess potential bias with community controls. From October 2012 through November 2016, patients with acute watery diarrhea were recruited from cholera treatment centers in rural Haiti. Cholera cases had a positive stool culture. Non-cholera diarrhea cases (test-negative controls and non-cholera diarrhea cases for bias-indicator analyses) had a negative culture and rapid test. Up to four community controls were matched to diarrhea cases by age group, time, and neighborhood. Primary analyses included 181 cholera cases, 157 non-cholera diarrhea cases, 716 VE community controls and 625 bias-indicator community controls. VE for self-reported vaccination with two doses was consistent across the two control groups, with statistically significant VE estimates ranging from 72 to 74%. Sensitivity analyses revealed similar, though somewhat attenuated estimates for self-reported two dose VE. Bias-indicator estimates were consistently less than one, with VE estimates ranging from 19 to 43%, some of which were statistically significant. OCV estimates from case-control analyses using community and test-negative controls were similar. While bias-indicator analyses suggested possible over-estimation of VE estimates using community controls, test-negative analyses suggested this bias, if present, was minimal. Test-negative controls can be a valid low-cost and time-efficient alternative to community controls for OCV effectiveness estimation and may be especially relevant in emergency situations. Copyright © 2017. Published by Elsevier Ltd.

White rice consumption and risk of esophageal cancer in Xinjiang Uyghur Autonomous Region, northwest China: a case-control study

OpenAIRE

Tang, Li; Xu, Fenglian; Zhang, Taotao; Lei, Jun; Binns, Colin W.; Lee, Andy H.

2015-01-01

This study investigated the association between white rice consumption and the risk of esophageal cancer in remote northwest China, where the cancer incidence is known to be high. A case-control study was conducted during 2008?2009 in Urumqi and Shihezi, Xinjiang Uyghur Autonomous Region of China. Participants were 359 incident esophageal cancer patients and 380 hospital-based controls. Information on habitual white rice consumption was obtained by personal interview using a validated semi-qu...

National outbreak of Salmonella Enteritidis phage type 14b in England, September to December 2009: case-control study.

Science.gov (United States)

Janmohamed, K; Zenner, D; Little, C; Lane, C; Wain, J; Charlett, A; Adak, B; Morgan, D

2011-04-14

We conducted an unmatched retrospective case–control study to investigate an upsurge of non-travel-related sporadic cases of infection with Salmonella enterica subsp. enterica serotype Enteritidis phage type 14b with antimicrobial resistance to nalidixic acid and partial resistance to ciprofloxacin (S. Enteritidis PT 14b NxCp(L)) that was reported in England from 1 September to 31 December 2009. We analysed data from 63 cases and 108 controls to determine whether cases had the same sources of infection as those found through investigation of 16 concurrent local foodborne outbreaks in England and Wales. Multivariable logistic regression analysis adjusting for age and sex identified food consumption at restaurants serving Chinese or Thai cuisine (odds ratio (OR): 4.4; 95% CI: 1.3–14.8; p=0.02), egg consumed away from home (OR: 5.1; 95% CI: 1.3–21.2; p=0.02) and eating vegetarian foods away from home (OR: 14.6; 95% CI: 2.1–99; p=0.006) as significant risk factors for infection with S. Enteritidis PT 14b NxCp(L). These findings concurred with those from the investigation of the16 outbreaks, which identified the same Salmonella strain in eggs from a specified source outside the United Kingdom. The findings led to a prohibition of imports from this source, in order to control the outbreak.

ICOS gene polymorphisms are associated with sporadic breast cancer: a case-control study

International Nuclear Information System (INIS)

Xu, Fengyan; Li, Dalin; Zhang, Qiujin; Fu, Zhenkun; Zhang, Jie; Yuan, Weiguang; Chen, Shuang; Pang, Da; Li, Dianjun

2011-01-01

Inducible costimulator (ICOS), a costimulatory molecular of the CD28 family, provides positive signal to enhance T cell proliferation. Its abnormal expression can disturb the immune response and entail an increased risk of cancer. To investigate whether single nucleotide polymorphisms (SNPs) in the ICOS gene are associated with sporadic breast cancer susceptibility and progression in Chinese women, a case-control study was conducted. In the study cohort, we genotyped five SNPs (rs11889031, rs10932029, rs4675374, rs10183087 and rs10932037) in ICOS gene among 609 breast cancer patients and 665 age-matched healthy controls. Furthermore, the positive results were replicated in an independent validation cohort of 619 patients and 682 age-matched healthy controls. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine the genotypes. In rs10932029, compared with TT genotype and T allele, the CT genotype and C allele showed a significantly increased risk of breast cancer (P = 0.030, OR = 1.467, 95% CI 1.037-2.077; P = 0.017, OR = 1.481, 95% CI 1.070-2.049, respectively), and the associations were also significant in the validation cohort (P = 0.002, OR = 1.693, 95% CI 1.211-2.357; P = 0.003, OR = 1.607, 95% CI 1.171-2.204, respectively). Haplotype analysis showed that CTCAC haplotype containing rs10932029 T allele had a lower frequency in cases than in controls (P = 0.015), whereas haplotype CCCAC containing rs10932029 C allele was more common in cases than in controls (P = 0.013). In the analysis of clinicopathologic features, rs11889031 CT genotype and T allele were associated with progesterone receptor (PR) status and lymph node metastasis, which were further supported by our validation cohort. Moreover, some haplotypes were associated with estrogen receptor (ER) and PR statuses. These results indicate that ICOS gene polymorphisms may affect the risk of breast cancer and show that some SNPs are associated with breast cancer

High risk human papillomavirus in the periodontium : A case control study

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Anna Shipilova

2017-01-01

Full Text Available Background: Human papilloma viruses (HPVs are small DNA viruses that have been identified in periodontal pocket as well as gingival sulcus. High risk HPVs are also associated with a subset of head and neck carcinomas. It is thought that the periodontium could be a reservoir for HPV. Aims: 1. Detection of Human Papilloma virus (HPV in periodontal pocket as well as gingival of patients having localized chronic periodontitis and gingival sulcus of periodontally healthy subjects. 2. Quantitative estimation of E6 and E7 mRNA in subjects showing presence of HPV3. To assess whether periodontal pocket is a reservoir for HPV. Settings and Design: This case-control study included 30 subjects with localized chronic Periodontitis (cases and 30 periodontally healthy subjects (controls. Two samples were taken from cases, one from periodontal pocket and one from gingival sulcus and one sample was taken from controls. Methods and Materials: Samples were collected in the form of pocket scrapings and gingival sulcus scrapings from cases and controls respectively. These samples were sent in storage media for identification and estimation of E6/E7 mRNA of HPV using in situ hybridization and flow cytometry. Statistical analysis: Statistical analysis was done by using, mean, percentage and Chi Square test. A statistical package SPSS version 13.0 was used to analyze the data. P value < 0.05 was considered as statistically significant. Results: pocket samples as well as sulcus samples for both cases and controls were found to contain HPV E6/E7 mRNAInterpretation and Conclusion: Presence of HPV E6/E7 mRNA in periodontium supports the hypothesis that periodontal tissues serve as a reservoir for latent HPV and there may be a synergy between oral cancer, periodontitis and HPV. However prospective studies are required to further explore this link.

Gender-specific suicide risk factors: a case-control study of individuals with major depressive disorder.

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Dalca, Ioana Mioara; McGirr, Alexander; Renaud, Johanne; Turecki, Gustavo

2013-12-01

Available information on risk for suicide completion in females is limited and often extrapolated from studies conducted in males. However, the validity of extending to females risk factors identified among male suicide cases is unclear. In this study, we aimed to investigate clinical and behavioral risk factors for suicide among female depressed patients and compare them to similar factors among male depressed patients. We identified 201 suicide completers (160 male and 41 female) who died during an episode of major depressive disorder (MDD). Cases were compared to 127 living patients with MDD (88 male and 39 female). All subjects were characterized for Axis I and II diagnoses using the Structured Clinical Interview for DSM-IV Axis I Disorders and Structured Clinical Interview for DSM-IV Axis II Personality Disorders according to the DSM-IV, as well as behavioral and temperament dimensions using proxy-based interviews. The primary outcome was measures of impulsive and impulsive-aggressive behaviors. Compared to controls, male, but not female suicide cases had higher levels of impulsive aggression (P suicide cases from controls. However, nonimpulsive aggression and impulsive aggression were correlated constructs in males (r = 0.297; P suicide, such as alcohol and substance dependence, cluster B disorders, and elevated hostility and aggression, were replicated in the pooled-sex analyses, and, though not statistically significant in discriminating between suicide cases and controls by gender, maintained strong group differences. Males and females share many risk factors for suicide in MDD, yet alcohol dependence is much more specific though less sensitive among depressed females. Nonimpulsive aggression is part of a diathesis for suicide in females, which is distinct from the well-characterized impulsive aggression that is consistently reported in a portion of male suicide cases. © Copyright 2013 Physicians Postgraduate Press, Inc.

Psychiatric morbidity in psoriasis: A case-control study

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Sunil Goyal

2017-01-01

Full Text Available Objective: Psoriasis is a chronic, relapsing and disfiguring dermatological disorder with a significant effect on occupational, social, and other areas of functioning. Psychological stress has been known to have a significant role in the onset and exacerbation of this illness. To study the prevalence of psychiatric morbidity in psoriasis and the influence of specified demographic, psychological, social and illness-related variables. Methods: The study was carried out at a tertiary care hospital in a large urban setup. In this case–control study, 100 cases of psoriasis were studied in comparison with healthy controls who were matched for sociodemographic profile. The participants were given a sociodemographic questionnaire, clinical profile sheet, and psoriasis area and severity index (PASI. General Health Questionnaire-12 (GHQ-12 was used to screen for psychological distress, and subsequently, Hospital Anxiety and Depression Scale for screening for depression and anxiety and World Health Organization Quality of Life-BREF scale for assessing the quality of life (QOL were administered. The results obtained were analyzed for evaluating the psychiatric morbidity and its various correlates. Appropriate statistical analysis was done using SPSS 21. Results: Using GHQ-12 cutoff score (≥3 for psychological distress, the overall prevalence of psychological distress was significantly more in cases of in comparison to healthy controls with an odds ratio of 8.54 (95% confidence interval 3.16–23.07, P < 0.0001. Statistical analysis showed a statistically significant correlation of educational status with QOL and severity of skin lesions (PASI with anxiety level. Severe skin lesions, more so on visible body parts were associated more commonly with psychological distress. Conclusions: All patients of psoriasis should be educated about the nature of the illness and screened for psychological distress. Dermatologists and family members should be educated to

Selection of controls in case-control studies on maternal medication use and risk of birth defects

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Bakker, M.K.; de Walle, H.E.; Dequito, A.; van den Berg, P.B.; de Jong-van den Berg, L.T.

BACKGROUND:: In case-control studies on teratogenic risks of maternal drug use during pregnancy, the use of normal or malformed controls may lead to recall-bias or selection bias. This can be avoided by using controls with a genetic disorder. However, researchers are hesitant to use these as

Nitrate in drinking water and risk of death from bladder cancer: an ecological case-control study in Taiwan.

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Chiu, Hui-Fen; Tsai, Shang-Shyue; Yang, Chun-Yuh

2007-06-01

The relationship between nitrate levels in drinking water and bladder cancer development is controversial. A matched cancer case-control with nitrate ecology study was used to investigate the association between bladder cancer mortality occurrence and nitrate exposure from Taiwan drinking water. All bladder cancer deaths of Taiwan residents from 1999 through 2003 were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. Controls were deaths from other causes and were pair-matched to the cases by gender, year of birth,and year of death. Each matched control was selected randomly from the set of possible controls for each cancer case. Data on nitrate-nitrogen (NO3-N) levels in drinking water throughout Taiwan were collected from Taiwan Water Supply Corporation (TWSC). The municipality of residence for cancer cases and controls was assumed to be the source of the subject's nitrate exposure via drinking water. The adjusted odds ratios for bladder cancer death for those with high nitrate levels in their drinking water were 1.76 (1.28-2.42) and 1.96 (1.41-2.72) as compared to the lowest tertile. The results of the present study show that there was a significant positive relationship between the levels of nitrate in drinking water and risk of death from bladder cancer.

Association between phytosterol intake and colorectal cancer risk: a case-control study.

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Huang, Jing; Xu, Ming; Fang, Yu-Jing; Lu, Min-Shan; Pan, Zhi-Zhong; Huang, Wu-Qing; Chen, Yu-Ming; Zhang, Cai-Xia

2017-03-01

A study in rodent models showed that phytosterols protected against colon carcinogenesis, probably by inhibiting dysregulated cell cycle progression and inducing cellular apoptosis. However, epidemiological studies on the relationship between phytosterols and colorectal cancer risk are quite limited. The aim of this study was to investigate dietary phytosterol intake in relation to colorectal cancer risk in the Chinese population. A case-control study was conducted from July 2010 to June 2016, recruiting 1802 eligible colorectal cancer cases plus 1813 age (5-year interval) and sex frequency-matched controls. Dietary information was collected by using a validated FFQ. The OR and 95 % CI of colorectal cancer risk were assessed by multivariable logistic regression models. A higher total intake of phytosterols was found to be associated with a 50 % reduction in colorectal cancer risk. After adjusting for various confounders, the OR of the highest quartile intake compared with the lowest quartile intake was 0·50 (95 % CI 0·41, 0·61, P trendphytosterols. An inverse association was also found between the consumption of β-sitosterol, campesterol, campestanol and colorectal cancer risk. However, stigmasterol intake was related to an increased risk of colorectal cancer. No statistically significant association was found between β-sitostanol and colorectal cancer risk. Stratified analysis by sex showed that the positive association of stigmasterol intake with colorectal cancer risk was found only in women. These data indicated that the consumption of total phytosterols, β-sitosterol, campesterol and campestanol is inversely associated with colorectal cancer risk in a Chinese population.

Dietary inflammation potential and postmenopausal breast cancer risk in a German case-control study.

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Ge, Isabell; Rudolph, Anja; Shivappa, Nitin; Flesch-Janys, Dieter; Hébert, James R; Chang-Claude, Jenny

2015-08-01

Unhealthy dietary habits can increase the risk for serious medical conditions, such as cancer, yet the association between diet and breast cancer remains unclear. We investigated whether individual diets based on their inflammatory potential are associated with postmenopausal breast cancer risk by employing an energy-adjusted dietary inflammation index. In a German population-based case-control study, 2887 postmenopausal breast cancer patients (aged 50-74 years, first diagnosed between 2002 and 2005) and 5512 healthy age-matched controls provided information on dietary habits for the year prior to diagnosis (cases) or recruitment (controls) using a 176-items food frequency questionnaire. Associations between the energy-adjusted dietary inflammation index (E-DII) score (both as continuous variable and in quintiles) and risk for breast cancer were assessed using conditional logistic regression adjusted for potential confounders. No significant associations between the E-DII score and postmenopausal breast cancer risk were observed (adjusted OR Q5 vs Q1: 1.01, 95% CI: 0.86-1.17). Associations did not differ by estrogen receptor/progesterone receptor status (ER + PR+: adjusted OR Q5 vs Q1: 1.06, 95% CI: 0.88-1.27; ER + or PR+: OR Q5 vs Q1: 1,07, 95% CI: 0.79-1.45; ER-PR-: OR Q5 vs Q1: 0.87 95% CI: 0.63-1.20). Our results regarding E-DII are consistent with previous studies reporting a lack of association between C-reactive protein, a marker of systemic inflammation, and postmenopausal breast cancer risk. The findings may reflect a real absence of association between dietary inflammatory potential and postmenopausal cancer risk or an underestimation of association due to recall bias. Further investigation is warranted in cohort studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Investigation of Plasminogen Activator Inhibitor-1 (PAI-1) 4G/5G promoter polymorphism in Indian venous thrombosis patients: A case-control study.

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Prabhudesai, Aniket; Shetty, Shrimati; Ghosh, Kanjaksha; Kulkarni, Bipin

2017-09-01

The role of PAI-1 4G/5G polymorphism in venous thrombosis has been contradictory. PAI-1 4G/4G genotype is associated with elevated levels of PAI-1 resulting in a hypofibrinolytic state and a higher thrombotic risk. In this study, the distribution of genotypes and frequency of alleles of the 4G/5G polymorphism of PAI-1 gene in Indian patients with different types of venous thrombosis was investigated for its role in development of thrombosis. A total of 87 portal vein thrombosis (PVT), 71 Budd-Chiari syndrome (BCS), 156 cerebral vein thrombosis (CVT), and 163 deep vein thrombosis (DVT) patients were studied alongside 251 healthy controls for the PAI-1 4G/5G polymorphism by allele-specific PCR. Frequency of 4G/4G genotype was higher in all groups in comparison with controls. 4G/4G was associated with PVT risk (OR=2.51, 95% CI=1.29-4.96, P=.0075), BCS risk (OR=5.98, 95% CI=2.68-13.42, P<.0001), and DVT risk (OR=1.75, 95% CI=0.98-3.02, P=.0225). This is the first case-control study from India establishing PAI-1 4G/4G as a strong risk factor for abdominal thrombosis (PVT and BCS). Statistically significant association was not found between 4G/4G genotype and CVT risk. PAI-1 4G/4G is a strong risk factor for venous thrombosis in Indian patients and should be included in laboratory testing panel of thrombophilia. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

An Outbreak of Vancomycin-Resistant Enterococcus faecium in an Acute Care Pediatric Hospital: Lessons from Environmental Screening and a Case-Control Study

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Steven J Drews

2008-01-01

Full Text Available BACKGROUND: The present study describes a vancomycin-resistant enterococci (VRE outbreak investigation and a case-control study to identify risk factors for VRE acquisition in a tertiary care pediatric hospital.

Co-Prevalence of Tremor with Spasmodic Dysphonia: A Case-Control Study

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White, Laura; Klein, Adam; Hapner, Edie; Delgaudio, John; Hanfelt, John; Jinnah, H. A.; Johns, Michael

2011-01-01

OBJECTIVES/HYPOTHESIS The aim of this study was to define the co-prevalence of tremor with spasmodic dysphonia (SD). STUDY DESIGN A single institution prospective, case-control study was performed from May 2010 to July 2010. METHODS Consecutive patients with SD (cases) and other voice disorders (controls) were enrolled prospectively. Each participant underwent a voice evaluation and an evaluation for tremor. RESULTS 146 voice disorder controls and 128 patients with SD were enrolled. 26% of patients with SD had vocal tremor, 21% had non-vocal tremor. Patients with SD were 2.8 times more likely to have co-prevalent tremor than the control group (OR = 2.81; 95% CI, 1.55 to 5.08) and only 35% of patients with SD had been seen by a neurologist for the evaluation of dystonia and tremor. CONCLUSIONS Tremor is highly prevalent in patients with SD. It is important for each patient diagnosed with SD to undergo an evaluation for tremor, this is especially important in patients diagnosed with vocal tremor. Level of evidence 3b. PMID:21792965

Human Papillomavirus Antibodies and Future Risk of Anogenital Cancer : A Nested Case-Control Study in the European Prospective Investigation Into Cancer and Nutrition Study

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Kreimer, Aimee R.; Brennan, Paul; Kuhs, Krystle A. Lang; Waterboer, Tim; Clifford, Gary; Franceschi, Silvia; Michel, Angelika; Willhauck-Fleckenstein, Martina; Riboli, Elio; Castellsague, Xavier; Hildesheim, Allan; Fortner, Renee Turzanski; Kaaks, Rudolf; Palli, Domenico; Ljuslinder, Ingrid; Panico, Salvatore; Clavel-Chapelon, Francoise; Boutron-Ruault, Marie-Christine; Mesrine, Sylvie; Trichopoulou, Antonia; Lagiou, Pagona; Trichopoulos, Dimitrios; Peeters, Petra H.; Cross, Amanda J.; Bueno-de-Mesquita, H. Bas; Vineis, Paolo; Larranaga, Nerea; Pala, Valeria; Sanchez, Maria-Jose; Navarro, Carmen; Barricarte, Aurelio; Tumino, Rosario; Khaw, Kay-Tee; Wareham, Nicholas; Boeing, Heiner; Steffen, Annika; Travis, Ruth C.; Ramon Quiros, J.; Weiderpass, Elisabete; Pawlita, Michael; Johansson, Mattias

2015-01-01

Purpose Human papillomavirus (HPV) type 16 (HPV16) causes cancer at several anatomic sites. In the European Prospective Investigation Into Cancer and Nutrition study, HPV16 E6 seropositivity was present more than 10 years before oropharyngeal cancer diagnosis and was nearly absent in controls. The

Modified metabolic syndrome and second cancers in women: A case control study.

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Ortiz-Mendoza, Carlos-Manuel; Pérez-Chávez, Ernesto; Fuente-Vera, Tania-Angélica De-la

2016-01-01

According to some studies, the metabolic syndrome causes diverse primary cancers; however, there is no evidence about metabolic syndrome impact on second cancers development in women. To find out the implication of the modified metabolic syndrome in women with second cancers. This was a case-control study, at a general hospital in Mexico City, in women with second cancers (cases) and age-matched women with only one neoplasm (controls). The analysis comprised: Tumor (s), anthropometric features, and body mass index (BMI); moreover, presence of diabetes mellitus, hypertension, and fasting serum levels of total cholesterol, triglycerides and glucose. The sample was of nine cases and 27 controls. In cases, the metabolic syndrome (diabetes mellitus or glucose > 99 mg/dL + hypertension or blood pressure ≥ 135/85 mm Hg + triglycerides > 149 mg/dL or BMI ≥ 30 kg/m 2 ) was more frequent (odds ratio 20.8, 95% confidence interval: 1.9-227.1). Our results suggest that in women, the modified metabolic syndrome may be a risk factor for second cancers.

Modified metabolic syndrome and second cancers in women: A case control study

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Carlos-Manuel Ortiz-Mendoza

2016-01-01

Full Text Available Background: According to some studies, the metabolic syndrome causes diverse primary cancers; however, there is no evidence about metabolic syndrome impact on second cancers development in women. Aim: To find out the implication of the modified metabolic syndrome in women with second cancers. Materials and Methods: This was a case-control study, at a general hospital in Mexico City, in women with second cancers (cases and age-matched women with only one neoplasm (controls. The analysis comprised: Tumor (s, anthropometric features, and body mass index (BMI; moreover, presence of diabetes mellitus, hypertension, and fasting serum levels of total cholesterol, triglycerides and glucose. Results: The sample was of nine cases and 27 controls. In cases, the metabolic syndrome (diabetes mellitus or glucose > 99 mg/dL + hypertension or blood pressure ≥ 135/85 mm Hg + triglycerides > 149 mg/dL or BMI ≥ 30 kg/m 2 was more frequent (odds ratio 20.8, 95% confidence interval: 1.9-227.1. Conclusion: Our results suggest that in women, the modified metabolic syndrome may be a risk factor for second cancers.

Determinants of the incidence of childhood asthma: a two-stage case-control study.

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Martel, Marie-Josée; Rey, Evelyne; Malo, Jean-Luc; Perreault, Sylvie; Beauchesne, Marie-France; Forget, Amélie; Blais, Lucie

2009-01-15

Extensive literature exists on potential risk factors for childhood asthma. To the authors' knowledge, no investigators have yet attempted to disentangle the effects of those determinants within a single study setting. The authors aimed to evaluate the independent effects of 47 potential determinants (from the prenatal, perinatal, and childhood periods) of asthma development in children within the first 10 years of life. From a Canadian birth cohort of 26,265 children (1990-2002), a 2-stage case-control study was conducted. In the first stage, 20 controls per case were selected from 3 administrative databases. In the second stage, selected mothers were mailed questionnaires for assessment of additional determinants. Increased risks of childhood asthma were found for > or =1 previous diagnosis of bronchopulmonary disease and atopic dermatitis in the child, oxygen administration after birth, prescription of antibiotics within the first 6 months of life, male gender, asthma during pregnancy, use of antibiotics during pregnancy, maternal receipt of social aid, paternal asthma, and asthma in siblings. Protective effects included use of intranasal corticosteroids during pregnancy, having a wood-burning fireplace, having pets in the home prior to the index date, breastfeeding, and day-care attendance. This study allowed the authors to identify, within a single setting, the most influential determinants of childhood asthma among 47 predictors assessed for the prenatal, perinatal, and childhood periods.

Adipokines as Possible New Predictors of Cardiovascular Diseases: A Case Control Study

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Laura Pala

2012-01-01

Full Text Available Background and Aims. The secretion of several adipocytokines, such as adiponectin, retinol-binding protein 4 (RBP4, adipocyte fatty acid binding protein (aFABP, and visfatin, is altered in subjects with abdominal adiposity; these endocrine alterations could contribute to increased cardiovascular risk. The aim of the study was to assess the relationship among adiponectin, RBP4, aFABP, and visfatin, and incident cardiovascular disease. Methods and Results. A case-control study, nested within a prospective cohort, on 2945 subjects enrolled for a diabetes screening program was performed. We studied 18 patients with incident fatal or nonfatal IHD (Ischemic Heart Disease or CVD (Cerebrovascular Disease, compared with 18 matched control subjects. Circulating adiponectin levels were significantly lower in cases of IHD with respect to controls. Circulating RBP4 levels were significantly increased in CVD and decreased in IHD with respect to controls. Circulating aFABP4 levels were significantly increased in CVD, while no difference was associated with IHD. Circulating visfatin levels were significantly lower in cases of both CVD and IHD with respect to controls, while no difference was associated with CVD. Conclusions. The present study confirms that low adiponectin is associated with increased incidents of IHD, but not CVD, and suggests, for the first time, a major effect of visfatin, aFABP, and RBP4 in the development of cardiovascular disease.

Identifying risk factors for blindness from primary open-angle glaucoma by race: a case-control study.

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Williams, Andrew M; Huang, Wei; Muir, Kelly W; Stinnett, Sandra S; Stone, Jordan S; Rosdahl, Jullia A

2018-01-01

To examine the factors associated with blindness from primary open-angle glaucoma (POAG) among black and white patients at our institution. For this retrospective, case-control study, patients legally blind from POAG ("cases") were matched on age, race, and gender with non-blind POAG patients ("controls"). Thirty-seven black case-control pairs and 19 white case-control pairs were included in this study. Clinical variables were compared at initial presentation and over the course of follow-up. Black case-control pairs and white case-control pairs had similar characteristics at presentation, including cup-to-disc ratio and number of glaucoma medications. However, over the course of follow-up, black cases underwent significantly more glaucoma surgeries than matched controls (2.4 versus 1.2, p =0.001), whereas white cases and controls had no significant difference in glaucoma operations (0.9 versus 0.6, p =0.139). Our analysis found that glaucoma surgery is associated with blindness in black patients (odds ratio [OR] 1.6, 95% CI 1.1-2.2) but not in white patients (OR 1.5, 95% CI 0.7-3.2). Black and white case-control pairs with POAG shared similar risk factors for blindness at presentation. However, over the follow-up period, black cases required significantly more glaucoma surgeries compared to black controls, whereas there was no significant difference in surgery between white cases and controls. There was no difference in medication changes in either case-control set.

An Epidemiological Study of Accidents in a Construction Industry: A Case-Control Study

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Malakouti J.

2013-01-01

Full Text Available Background and Objectives: Despite science and technology development and their application in various industries, accidents continue to occur in many workplaces. This study was designed and carried out with the aim of epidemiological survey of accident among workers of a tunneling industry.Methods: This study was conducted on 144 out of a total of 440 employees of a tunneling project who were at risk of occupational accidents. 48 workers with a history of occupational accident over the past two years were selected as case group and 96 workers of the same project were selected as control group. The data were collected through a designed checklist and analyzed using logistic regression, chi-square and independent t tests.Results: A significant association was observed between accident rate and different age groups (p<0.05. There was a significant relationship (p=0.016 in the case of sport activities between case and control groups, and significant relationships were observed between two groups regarding education (p=0.057 and smoking (p=0.06, but there was no significant relationships between accident occurrence with marital status, residence in workplace, job related education, job experience, chronic diseases and obesity.Conclusion: The results of this study clarify the necessity of the use of epidemiological data in preventive and control measures in workplaces. Therefore, Developing programs for determination of physical and mental capacity of workers are essential to employ them in jobs commensurate with their abilities, especially in older workers.

Externalizing behavior and impulsivity in the children of alcoholics: A case-control study

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Ayyanar Sugaparaneetharan

2016-01-01

Full Text Available Context: Reduced behavioural inhibition, characterized by impulsivity and disruptive behaviour disorders, has been identified as a developmental precursor of alcoholism with a considerable genetic component. Aims: The present study aimed to assess whether children of fathers with alcohol dependence have high impulsivity and externalizing behaviours. Setting and Design: Observational case-control study, done in a tertiary care teaching hospital of Southern India. Materials and Methods: The present case-control study recruited 50 children aged 7 to 14 years of fathers with alcohol dependence and 50 age- and gender-matched children of fathers without alcohol dependence. The two groups were compared using the DSM-IV-TR criteria for ADHD, the Barratt Impulsivity Scale (BIS and the Child Behaviour Checklist (CBCL. Statistical Analysis Used: Descriptive statistics used to summarise the study findings. Cases and controls were compared on BIS and CBCL scores using a general linear model (GLM. All analyses were two tailed and test P value <0.05 was considered significant. Results: The children of fathers with alcohol dependence were more likely to meet criteria for ADHD (30% versus 10%, χ2 = 6.250, P = 0.012. After controlling for age and gender, impulsivity scores on the BIS tended to be higher in the cases (F = 2.410, P = 0.055 than controls, mainly in the non-planning domains (F = 3.650, P = 0.008. Similarly, externalizing behaviours on CBCL were more common in the cases than controls (F = 2.817, P = 0.029. Conclusions: Children of fathers with alcohol dependence had greater impulsivity and externalizing behaviours. This may represent a behavioural phenotype as well as a potential target for early intervention.

A case-control study of airways obstruction among construction workers.

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Dement, John; Welch, Laura; Ringen, Knut; Quinn, Patricia; Chen, Anna; Haas, Scott

2015-10-01

While smoking is the major cause of chronic obstructive pulmonary disease (COPD), occupational exposures to vapors, gases, dusts, and fumes (VGDF) increase COPD risk. This case-control study estimated the risk of COPD attributable to occupational exposures among construction workers. The study population included 834 cases and 1243 controls participating in a national medical screening program for older construction workers between 1997 and 2013. Qualitative exposure indices were developed based on lifetime work and exposure histories. Approximately 18% (95% CI = 2-24%) of COPD risk can be attributed to construction-related exposures, which are additive to the risk contributed by smoking. A measure of all VGDF exposures combined was a strong predictor of COPD risk. Construction workers are at increased risk of COPD as a result of broad and complex effects of many exposures acting independently or interactively. Control methods should be implemented to prevent worker exposures, and smoking cessation should be promoted. © 2015 The Authors. American Journal of Industrial Medicine Published by Wiley Periodicals, Inc.

Clinical implications of antiretroviral drug interactions with warfarin: a case-control study.

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Esterly, John S; Darin, Kristin M; Gerzenshtein, Lana; Othman, Fidah; Postelnick, Michael J; Scarsi, Kimberly K

2013-06-01

Warfarin, a frequently prescribed anticoagulant with a narrow therapeutic index, is susceptible to drug-drug interactions with antiretroviral therapy (ART). This study compared the warfarin maintenance dose (WMD) between patients receiving and not receiving ART and evaluated predictors of warfarin dosage among those on ART. This was a case-control (1:2) study. Cases were HIV-infected patients receiving warfarin and protease inhibitor (PI)- and/or non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART. Controls were randomly selected HIV-uninfected patients receiving warfarin. The WMD was compared between cases and controls and between cases on varying ART regimens. Bivariate comparisons were performed and a linear regression model was developed to identify predictors of WMD. We identified 18 case and 36 control patients eligible for inclusion. Cases were younger than controls (mean age: 45.8 versus 63.1 years, P African American (50.0% versus 22.2%, P=0.04). ART was classified as PI-based (n=9), NNRTI-based (n=7) and PI + NNRTI-based (n=2). The WMD (mean ± SD) differed between cases and controls (8.6  ±  3.4 mg versus 5.1 ± 1.5 mg, P ART regimens (PI: 8.8  ±  4.5 mg; NNRTI: 8.6   ± 1.8 mg; PI + NNRTI: 7.3  ±  3.3 mg; P = 0.86). Race and ritonavir dose were independent predictors of WMD, predicting an increase of 3.9 mg (95% CI: 0.88-6.98, P = 0.02) if a patient was African American or 3.7 mg (95% CI: 0.53-6.89, P = 0.03) if the total daily ritonavir dose was 200 mg. The required WMD was significantly higher in patients receiving ART. Prompt dose titration to achieve a higher WMD with vigilant monitoring may be required due to these drug-drug interactions.

On estimation of time-dependent attributable fraction from population-based case-control studies.

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Zhao, Wei; Chen, Ying Qing; Hsu, Li

2017-09-01

Population attributable fraction (PAF) is widely used to quantify the disease burden associated with a modifiable exposure in a population. It has been extended to a time-varying measure that provides additional information on when and how the exposure's impact varies over time for cohort studies. However, there is no estimation procedure for PAF using data that are collected from population-based case-control studies, which, because of time and cost efficiency, are commonly used for studying genetic and environmental risk factors of disease incidences. In this article, we show that time-varying PAF is identifiable from a case-control study and develop a novel estimator of PAF. Our estimator combines odds ratio estimates from logistic regression models and density estimates of the risk factor distribution conditional on failure times in cases from a kernel smoother. The proposed estimator is shown to be consistent and asymptotically normal with asymptotic variance that can be estimated empirically from the data. Simulation studies demonstrate that the proposed estimator performs well in finite sample sizes. Finally, the method is illustrated by a population-based case-control study of colorectal cancer. © 2017, The International Biometric Society.

Sexual Dysfunction in Breast Cancer: A Case-Control Study

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Mandana Ebrahimi

2015-02-01

Full Text Available Background: Sexual dysfunction in breast cancer patients is considered as a common and distressing problem. Considering the increasing number of breast cancer survivors living for longer periods of time with the disease and the importance of their quality of life, we conducted the present study to compare the sexual functioning in breast cancer patients with their healthy counterparts.Methods: In this case-control study, breast cancer patients who completed their treatment protocol and were followed up for at least six months were included. The controls were healthy women with normal clinical breast examinations. All subjects filled-in the Persian version of Female Sexual Function Index questionnaire.Results: A total of 165 subjects including 71 breast cancer patients and 94 healthy women were studied. The frequency of sexual dysfunction in cases and controls was 52.6% and 47.4%, respectively (P = 0.09. There were no significant differences between the two groups regarding domain scores, except for vaginal lubrication (P = 0.045. Logistic regression analysis indicated that significant determinants of sexual dysfunction in breast cancer group was patients' age (OR = 4.0, 95%CI: 1.3 – 11.5, P = 0.01 and age of the spouse (OR= 9.8, 95% CI: 1.8-51.9, P= 0.007, while in controls, only emotional relationship with the husband was the significant predictive factor (OR = 6.3, 95%CI: 1.9 – 20.5, P = 0.002.Conclusions: Our findings indicated that sexual dysfunction is prevalent in Iranian women regardless of their physical health status. The frequency of vaginal dryness in breast cancer patients was significantly higher than controls. Age of the patient and the spouse (>40 were the only significant predictors of sexual dysfunction among women with breast cancer. Preventive strategies, sexual education and access to effective treatment should be planned in supportive care of breast cancer patients.

Salivary and microbiological parameters of chronic periodontitis subjects with and without type 2 diabetes mellitus: a case-control study

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José Roberto CORTELLI

Full Text Available Background: Several studies have investigated the differences in salivary parameters and microbial composition between diabetic and non-diabetic patients, however, specific differences are still not clear mainly due to the effects of confounder. Aim: The aim of this case-control study was to evaluate the salivary and microbial parameters of chronic periodontitis subjects with and without type 2 diabetes mellitus. Material and method: This case-control study included 60 chronic periodontitis subjects, 30 diabetics (case group and 30 non-diabetics (control group, paired according to periodontitis severity, gender and age. Stimulated whole saliva was collected from all volunteers to measure the salivary pH and the salivary flow rate. Bacterial samples were collected with paper points from periodontal sites showing the deepest periodontal pocket depth associated with the highest clinical attachment loss. The frequency of A. actinomycetemcomitans, P. intermedia, P. gingivalis, T. forsythia and C. rectus was evaluated by PCR. Data was statistically analyzed by Student's t, Mann-Whitney and Chi-square (p<0.05. Result: Diabetic subjects showed higher salivary glucose levels and lower stimulated flow rates in comparison to non-diabetic controls. P. gingivalis and T. forsythia were the most frequent pathogens (p<0.05. Bacterial frequency did not differ between case and control groups. Conclusion: Diabetes status influenced salivary glucose levels and flow rate. Within the same severity of chronic periodontitis, diabetic subjects did not show higher frequency of periodontal pathogens in comparison to their paired controls.

Entamoeba histolytica Infection in Female Sex Workers: A Matched Case-Control Study in Durango, Mexico.

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Alvarado-Esquivel, Cosme; Sanchez-Anguiano, Luis Francisco; Hernandez-Tinoco, Jesus; Estrada-Martinez, Sergio; Perez-Alamos, Alma Rosa; Ramos-Nevarez, Agar; Cerrillo-Soto, Sandra Margarita; Guido-Arreola, Carlos Alberto

2017-07-01

Infection with Entamoeba histolytica ( E. histolytica ) can be potentially transmitted by sexual contact. The seroepidemiology of E. histolytica in female sex workers has not been studied. The aim of the study was to determine whether E. histolytica is associated with the occupation of female sex work. In addition, the correlates of E. histolytica seroprevalence in female sex workers were also investigated. We performed an age- and gender-matched case-control study of 187 female sex workers and 374 women without sex work. Cases and controls were tested for the presence of E. histolytica IgG antibodies using a commercially available enzyme-linked immunoassay. Seroprevalence association with the characteristics of female sex workers was determined by bivariate analysis. Anti- E. histolytica IgG antibodies were found in five (2.7%) of 187 female sex workers and in 16 (4.3%) of 374 controls (odds ratios (OR) = 0.61; 95% confidence intervals (CI): 0.22 - 1.70; P = 0.34). Mean optical density of the immunoassay in seropositive cases and controls was 1.35 ± 0.93 and 0.73 ± 0.45, respectively (P = 0.05). Seroprevalence of E. histolytica infection did not vary significantly with age, education, socioeconomic level, or health status of sex workers. Seropositivity to E. histolytica did not correlate with work characteristics such as duration in the occupation, condom use, type of sex, or a history of sexually transmitted diseases, or with behavioral variables such as washing hands before eating, or consumption of untreated water. Results indicate that female sex workers do not have an increased risk for E. histolytica infection in Durango City, Mexico. Further studies to determine the risk of infection with E. histolytica by sexual contact should be conducted.

Naevi as a risk factor for basal cell carcinoma in Caucasians: a Danish case-control study

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Lock-Andersen, J; Drzewiecki, K T; Wulf, H C

1999-01-01

The number of melanocytic naevi in Caucasians is related to previous exposure to the sun and is a well-documented major risk factor for cutaneous malignant melanoma. Basal cell carcinoma, which is the most common form of skin cancer, has also been shown to be related to exposure to the sun....... To investigate whether the number of common naevi is a risk factor for basal cell carcinoma in Caucasians we performed whole-body counting of naevi > or =2 mm in a Danish case-control study with 145 cases of primary basal cell carcinoma and 119 controls matched on age, gender and place of residence. Naevi were...... recorded according to size and body region and the skin phototype was assessed. There was no correlation between self-reported skin type and the number of naevi. Females with basal cell carcinoma had more naevi than did female controls (median number of naevi: 65 and 32, respectively) while males...

A case-control study of wicket spikes using video-EEG monitoring.

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Vallabhaneni, Maya; Baldassari, Laura E; Scribner, James T; Cho, Yong Won; Motamedi, Gholam K

2013-01-01

To investigate clinical characteristics associated with wicket spikes in patients undergoing long-term video-EEG monitoring. A case-control study was performed in 479 patients undergoing video-EEG monitoring, with 3 age- (±3 years) and gender-matched controls per patient with wicket spikes. Logistic regression was utilized to investigate the association between wicket spikes and other factors, including conditions that have been previously associated with wicket spikes. Wicket spikes were recorded in 48 patients. There was a significantly higher prevalence of dizziness/vertigo (p=0.002), headaches (p=0.005), migraine (p=0.015), and seizures (p=0.016) in patients with wickets. The majority of patients with wicket spikes did not exhibit epileptiform activity on EEG; however, patients with history of seizures were more likely to have wickets (p=0.017). There was no significant difference in the prevalence of psychogenic non-epileptic seizures between the groups. Wickets were more common on the left, during sleep, and more likely to be first recorded on day 1-2 of monitoring. Patients with wicket spikes are more likely to have dizziness/vertigo, headaches, migraine, and seizures. Patients with history of seizures are more likely to have wickets. The prevalence of psychogenic non-epileptic seizures is not significantly higher in patients with wickets. Copyright © 2012 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

The environment as an unrecognized reservoir for community-associated methicillin resistant Staphylococcus aureus USA300: a case-control study.

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Anne-Catrin Uhlemann

Full Text Available BACKGROUND: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA infections are spreading, but the source of infections in non-epidemic settings remains poorly defined. METHODS: We carried out a community-based, case-control study investigating socio-demographic risk factors and infectious reservoirs associated with MRSA infections. Case patients presented with CA-MRSA infections to a New York hospital. Age-matched controls without infections were randomly selected from the hospital's Dental Clinic patient population. During a home visit, case and control subjects completed a questionnaire, nasal swabs were collected from index respondents and household members and standardized environmental surfaces were swabbed. Genotyping was performed on S. aureus isolates. RESULTS: We enrolled 95 case and 95 control subjects. Cases more frequently reported diabetes mellitus and a higher number of skin infections among household members. Among case households, 53 (56% were environmentally contaminated with S. aureus, compared to 36 (38% control households (p = .02. MRSA was detected on fomites in 30 (32% case households and 5 (5%; p<.001 control households. More case patients, 20 (21% were nasally colonized with MRSA than were control indexes, 2 (2%; p<.001. In a subgroup analysis, the clinical isolate (predominantly USA300, was more commonly detected on environmental surfaces in case households with recurrent MRSA infections (16/36, 44% than those without (14/58, 24%, p = .04. CONCLUSIONS: The higher frequency of environmental contamination of case households with S. aureus in general and MRSA in particular implicates this as a potential reservoir for recolonization and increased risk of infection. Environmental colonization may contribute to the community spread of epidemic strains such as USA300.

Risk of tinnitus in patients with sleep apnea: A nationwide, population-based, case-control study.

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Koo, Malcolm; Hwang, Juen-Haur

2017-09-01

To investigate the risk of tinnitus in patients with sleep disturbance or sleep apnea. Case control study. We identified 21,798 middle-aged and elderly patients with otolaryngologist-diagnosed tinnitus between January 1, 2000, and December 31, 2012, from the Longitudinal Health Insurance Database 2000 of the Taiwan National Health Insurance Research Database. A total of 108,990 controls were also identified from the same database based on frequency-matching on 10-year age interval, sex, and year of index date of the cases. Diagnoses of sleep disturbance (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] codes 780.50, 780.52, 307.4) and sleep apnea (ICD-9-CM codes 780.51, 780.53, 780.57) in the cases and controls prior to the index date were assessed. The risks of tinnitus in patients with sleep disturbance and sleep apnea were separately evaluated with multivariate logistic regression analyses. The mean age of the total 130,788 patients was 59.8 years, and 47% of them were males. The risk of tinnitus was higher in patients with sleep disturbance compared to those without the condition (adjusted odds ratio [OR] = 1.13, 95% confidence interval [CI] [95% CI] = 1.11-1.17), and the risk of tinnitus was higher in patients with sleep apnea compared to those without the condition (adjusted OR = 1.36, 95% CI = 1.16-1.60). In this population-based, case-control study, the risk of tinnitus was found to be significantly higher among middle-aged and elderly Taiwanese patients with sleep disturbances, especially with sleep apnea. 3b. Laryngoscope, 127:2171-2175, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Lifestyle Factors and Gender-Specific Risk of Stroke in Adults with Diabetes Mellitus: A Case-Control Study.

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Guo, Jian; Guan, Tianjia; Shen, Ying; Chao, Baohua; Li, Mei; Wang, Longde; Liu, Yuanli

2018-07-01

The lifestyle interventions are effective preventive measures for stroke in general population, and the stroke risk with lifestyle factors may be modified by gender, health conditions, etc. Therefore, we conducted a case-control study to investigate the gender-specific association between stroke risk and lifestyle factors in adults with diabetes based on the China National Stroke Screening Survey. Structured questionnaires were used to collect demographic data and information regarding lifestyle factors, history of chronic medical conditions, and family history of stroke and the status of treatment. The case group comprised individuals diagnosed with first-ever stroke in 2013-2014 screening period. Their corresponding controls (frequency-matched for age group and urban/rural ratio) were randomly selected from individuals with diabetes without stroke. There were 170 total stroke cases (500 controls) and 152 ischemic stroke cases (456 controls) among men with diabetes, and 183 total stroke cases (549 controls) and 168 ischemic stroke cases (504 controls) among women with diabetes. We found that physical inactivity was significantly associated with increased risk of total stroke (odds ratio [OR] = 1.50, 95% confidence interval [CI] 1.02-2.21) and of ischemic stroke (OR = 1.57, 95% CI 1.04-2.36) in women with diabetes. We found no significant association of smoking, overweight/obesity, or physical inactivity with risk of total or ischemic stroke in men with diabetes. Among the lifestyle factors of smoking, overweight/obesity, and physical inactivity, physical inactivity might increase the risk of total and ischemic stroke in women with diabetes. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Environmental and occupational risk factors for progressive supranuclear palsy: Case-control study.

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Litvan, Irene; Lees, Peter S J; Cunningham, Christopher R; Rai, Shesh N; Cambon, Alexander C; Standaert, David G; Marras, Connie; Juncos, Jorge; Riley, David; Reich, Stephen; Hall, Deborah; Kluger, Benzi; Bordelon, Yvette; Shprecher, David R

2016-05-01

The cause of progressive supranuclear palsy (PSP) is largely unknown. Based on evidence for impaired mitochondrial activity in PSP, we hypothesized that the disease may be related to exposure to environmental toxins, some of which are mitochondrial inhibitors. This multicenter case-control study included 284 incident PSP cases of 350 cases and 284 age-, sex-, and race-matched controls primarily from the same geographical areas. All subjects were administered standardized interviews to obtain data on demographics, residential history, and lifetime occupational history. An industrial hygienist and a toxicologist unaware of case status assessed occupational histories to estimate past exposure to metals, pesticides, organic solvents, and other chemicals. Cases and controls were similar on demographic factors. In unadjusted analyses, PSP was associated with lower education, lower income, more smoking pack-years, more years of drinking well water, more years living on a farm, more years living 1 mile from an agricultural region, more transportation jobs, and more jobs with exposure to metals in general. However, in adjusted models, only more years of drinking well water was significantly associated with PSP. There was an inverse association with having a college degree. We did not find evidence for a specific causative chemical exposure; higher number of years of drinking well water is a risk factor for PSP. This result remained significant after adjusting for income, smoking, education and occupational exposures. This is the first case-control study to demonstrate PSP is associated with environmental factors. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

Individual Correlates of Podoconiosis in Areas of Varying Endemicity: A Case-Control Study

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Molla, Yordanos B.; Le Blond, Jennifer S.; Wardrop, Nicola; Baxter, Peter; Atkinson, Peter M.; Newport, Melanie J.; Davey, Gail

2013-01-01

Background Podoconiosis is a non-filarial form of elephantiasis resulting in lymphedema of the lower legs. Previous studies have suggested that podoconiosis arises from the interplay of individual and environmental factors. Here, our aim was to understand the individual-level correlates of podoconiosis by comparing 460 podoconiosis-affected individuals and 707 unaffected controls. Methods/principal findings This was a case-control study carried out in six kebeles (the lowest governmental administrative unit) in northern Ethiopia. Each kebele was classified into one of three endemicity levels: ‘low’ (prevalence 5%). A total of 142 (30.7%) households had two or more cases of podoconiosis. Compared to controls, the majority of the cases, especially women, were less educated (OR = 1.7, 95% CI = 1.3 to 2.2), were unmarried (OR = 3.4, 95% CI = 2.6–4.6) and had lower income (t = −4.4, p<0.0001). On average, cases started wearing shoes ten years later than controls. Among cases, age of first wearing shoes was positively correlated with age of onset of podoconiosis (r = 0.6, t = 12.5, p<0.0001). Among all study participants average duration of shoe wearing was less than 30 years. Between both cases and controls, people in ‘high’ and ‘medium’ endemicity kebeles were less likely than people in ‘low’ endemicity areas to ‘ever’ have owned shoes (OR = 0.5, 95% CI = 0.4–0.7). Conclusions Late use of shoes, usually after the onset of podoconiosis, and inequalities in education, income and marriage were found among cases, particularly among females. There were clustering of cases within households, thus interventions against podoconiosis will benefit from household-targeted case tracing. Most importantly, we identified a secular increase in shoe-wearing over recent years, which may give opportunities to promote shoe-wearing without increasing stigma among those at high risk of podoconiosis. PMID:24340109

Individual correlates of podoconiosis in areas of varying endemicity: a case-control study.

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Yordanos B Molla

Full Text Available Podoconiosis is a non-filarial form of elephantiasis resulting in lymphedema of the lower legs. Previous studies have suggested that podoconiosis arises from the interplay of individual and environmental factors. Here, our aim was to understand the individual-level correlates of podoconiosis by comparing 460 podoconiosis-affected individuals and 707 unaffected controls.This was a case-control study carried out in six kebeles (the lowest governmental administrative unit in northern Ethiopia. Each kebele was classified into one of three endemicity levels: 'low' (prevalence 5%. A total of 142 (30.7% households had two or more cases of podoconiosis. Compared to controls, the majority of the cases, especially women, were less educated (OR = 1.7, 95% CI = 1.3 to 2.2, were unmarried (OR = 3.4, 95% CI = 2.6-4.6 and had lower income (t = -4.4, p<0.0001. On average, cases started wearing shoes ten years later than controls. Among cases, age of first wearing shoes was positively correlated with age of onset of podoconiosis (r = 0.6, t = 12.5, p<0.0001. Among all study participants average duration of shoe wearing was less than 30 years. Between both cases and controls, people in 'high' and 'medium' endemicity kebeles were less likely than people in 'low' endemicity areas to 'ever' have owned shoes (OR = 0.5, 95% CI = 0.4-0.7.Late use of shoes, usually after the onset of podoconiosis, and inequalities in education, income and marriage were found among cases, particularly among females. There were clustering of cases within households, thus interventions against podoconiosis will benefit from household-targeted case tracing. Most importantly, we identified a secular increase in shoe-wearing over recent years, which may give opportunities to promote shoe-wearing without increasing stigma among those at high risk of podoconiosis.

Higher dietary diversity score is associated with obesity: a case-control study.

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Karimbeiki, R; Pourmasoumi, M; Feizi, A; Abbasi, B; Hadi, A; Rafie, N; Safavi, S M

2018-04-01

The present study was carried out to compare dietary diversity score (DDS) among overweight, obese, and normal-weight adults. This case-control study was conducted with a total of 200 cases (100 participants with obesity and 100 participants with overweight) and 300 controls (normal weight) matched by socio-economic status (SES), older than 18 years. Dietary intakes were assessed using a self-administered Food Frequency Questionnaire. Data regarding physical activity and sociodemographic variables were gathered. DDS was computed based on the scoring of the five food groups emphasized in the United States Department of Agriculture Food Guide Pyramid. Anthropometric measurements were measured, and the body mass index and waist-to-hip ratio were calculated. The mean ± standard deviation of DDS was higher in participants with obesity (5.65 ± 1.32) than that in overweight participants (5.23 ± 1.23), while the lowest score was reported among normal-weight individuals (4.97 ± 1.42) (P obesity increased with each unit increase in DDS (odds ratio [OR]: 1.46; 95% confidence interval [CI]: 1.22, 1.74). However, the association became slightly weaker after adjusting for potential confounding factors (OR: 1.34; 95% CI: 1.07, 1.68). It was concluded that there was a significant positive association between DDS and obesity. However, additional investigations are warranted. Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Human papillomavirus (HPV) infection in a case-control study of oral squamous cell carcinoma and its increasing trend in northeastern Thailand.

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Phusingha, Pensiri; Ekalaksananan, Tipaya; Vatanasapt, Patravoot; Loyha, Kulchaya; Promthet, Supannee; Kongyingyoes, Bunkerd; Patarapadungkit, Natcha; Chuerduangphui, Jureeporn; Pientong, Chamsai

2017-06-01

Human papillomavirus (HPV) is an independent risk factor for development of oral squamous cell carcinoma (OSCC). This study aimed to investigate the role of HPV infection and the trend in percentage of HPV-associated OSCC over a 5-year period in northeastern Thailand. In this case-control study, 91 exfoliated oral cell samples and 80 lesion cell samples from OSCC cases and exfoliated oral cells from 100 age/gender-matched controls were collected. HPV infection was investigated by PCR using GP5+/GP6+ primers followed by HPV genotyping using reverse line blot hybridization. Quantitative RT-PCR was used to evaluate HPV oncogene transcription. Temporal trends of HPV infection were evaluated in archived formalin-fixed paraffin-embedded (FFPE) OSCC tissues using in situ hybridization. HPV DNA was found in 17.5% (14/80) of lesion samples from OSCC cases and 29.7% (27/91) of exfoliated oral cell samples from the same cases. These values were significantly higher than in exfoliated oral cell samples from controls (13%, 13/100). HPV-16 was the genotype most frequently found in OSCC cases (92.8%, 13/14 infected cases). Interestingly, HPV oncogene mRNA expression was detected and correlated with OSCC cases (P cases were positive for HPV E6/E7 mRNA expression. There was a trend of increasing percentage of HPV-associated OSCC from 2005 to 2010. This was especially so for females with well-differentiated tumors in specific tongue sub-sites. We suggest that HPV infection plays an important role in oral carcinogenesis in northeastern Thailand. © 2016 Wiley Periodicals, Inc.

Association between bullous pemphigoid and neurologic diseases: a case-control study.

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Casas-de-la-Asunción, E; Ruano-Ruiz, J; Rodríguez-Martín, A M; Vélez García-Nieto, A; Moreno-Giménez, J C

2014-11-01

In the past 10 years, bullous pemphigoid has been associated with other comorbidities and neurologic and psychiatric conditions in particular. Case series, small case-control studies, and large population-based studies in different Asian populations, mainland Europe, and the United Kingdom have confirmed this association. However, no data are available for the Spanish population. This was an observational, retrospective, case-control study with 1:2 matching. Fifty-four patients with bullous pemphigoid were selected. We compared the percentage of patients in each group with concurrent neurologic conditions, ischemic heart disease, diabetes, chronic obstructive pulmonary disease, and solid tumors using univariate logistic regression. An association model was constructed with conditional multiple logistic regression. The case group had a significantly higher percentage of patients with cerebrovascular accident and/or transient ischemic attack (odds ratio [OR], 3.06; 95% CI, 1.19-7.87], dementia (OR, 5.52; 95% CI, 2.19-13.93), and Parkinson disease (OR, 5; 95% CI, 1.57-15.94). A significantly higher percentage of cases had neurologic conditions (OR, 6.34; 95% CI, 2.89-13.91). Dementia and Parkinson disease were independently associated with bullous pemphigoid in the multivariate analysis. Patients with bullous pemphigoid have a higher frequency of neurologic conditions. Copyright © 2013 Elsevier España, S.L.U. and AEDV. All rights reserved.

The association between Anoplocephala perfoliata and colic in Swedish horses--a case control study.

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Back, H; Nyman, A; Osterman Lind, E

2013-11-08

A case-control study was performed to investigate the association between colic of all types in Swedish horses and infection with the equine tapeworm Anoplocephala perfoliata. Colic cases were defined by clinical signs consistent with the presence of abdominal pain, and the control horses had no signs of colic within the last year but attended a clinic for other reasons. Blood and fecal samples were collected by veterinarian from 67 horses with signs of colic and 67 control horses. The sera were analyzed using serodiagnostic assay anti-12/13 kDa IgG(T) ELISA. The fecal samples, 30 g from each horse, were analyzed with a modified sugar salt flotation method with a density of 1.280. A significant association was found between the presence of A. perfoliata eggs in feces and colic with a 16 times higher risk of colic if eggs had been observed in fecal samples. However, there was no significant association between colic and the median OD-values in the serological diagnosis, nor when recommended cut-offs were used. The study concludes that A. perfoliata is a risk factor for colic in Swedish horses and it suggests that the modified flotation method can be used as a diagnostic tool for identifying horses at risk. Copyright © 2013. Published by Elsevier B.V.

Risk factors for unintentional poisoning in children aged 1-3 years in NSW Australia: a case-control study.

Science.gov (United States)

Schmertmann, Marcia; Williamson, Ann; Black, Deborah; Wilson, Leigh

2013-05-24

Unintentional poisoning in young children is an important public health issue. Age pattern studies have demonstrated that children aged 1-3 years have the highest levels of poisoning risk among children aged 0-4 years, yet little research has been conducted regarding risk factors specific to this three-year age group and the methodologies employed varied greatly. The purpose of the current study is to investigate a broad range of potential risk factors for unintentional poisoning in children aged 1-3 years using appropriate methodologies. Four groups of children, one case group (children who had experienced a poisoning event) and three control groups (children who had been 'injured', 'sick' or who were 'healthy'), and their mothers (mother-child dyads) were enrolled into a case-control study. All mother-child dyads participated in a 1.5-hour child developmental screening and observation, with mothers responding to a series of questionnaires at home. Data were analysed as three case-control pairs with multivariate analyses used to control for age and sex differences between child cases and controls. Five risk factors were included in the final multivariate models for one or more case-control pairs. All three models found that children whose mothers used more positive control in their interactions during a structured task had higher odds of poisoning. Two models showed that maternal psychiatric distress increased poisoning risk (poisoning-injury and poisoning-healthy). Individual models identified the following variables as risk factors: less proximal maternal supervision during risk taking activities (poisoning-injury), medicinal substances stored in more accessible locations in bathrooms (poisoning-sick) and lower total parenting stress (poisoning-healthy). The findings of this study indicate that the nature of the caregiver-child relationship and caregiver attributes play an important role in influencing poisoning risk. Further research is warranted to explore the

Relationship of psychosocial risk factors, certain personality traits and myocardial infarction in Indians: A case-control study

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Rajni Gupta

2011-01-01

Full Text Available Objective: To investigate the relationship of psychosocial factors (lack of social support, stress and subjective well-being and personality traits with myocardial infarction (MI. Materials and Methods: A case-control study involving 100 cases and 100 matched controls was conducted in Lok Nayak Hospital, New Delhi. Results: Stress over 1 year was significantly higher in cases (P < 0.001. However, difference was not significant when scores of social support (P = 0.2, Presumptive Stressful Life Event (PSLE over lifetime (P = 0.058 and subjective well-being (P = 0.987 were compared. MI was significantly associated with hyperactive (P < 0.001, dominant (P = 0.03, egoistic (P < 0.001 and introvert (P < 0.001 personalities. Conclusion: Certain personality traits and recent stress may be important risk factors of MI, especially in Indians. The finding may have implications on the preventive strategies planned for MI patients.

The impact of glaucoma on quality of life in Ethiopia: a case-control study.

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Ayele, Fisseha A; Zeraye, Banchamelak; Assefa, Yared; Legesse, Kbrom; Azale, Telake; Burton, Matthew J

2017-12-13

Glaucoma is a chronic disease characterized by irreversible optic nerve damage and visual field loss that leads to visual impairment and blindness; ultimately limiting personal independence and compromising overall quality of life of affected individuals. There is paucity of information on how glaucoma affects the quality of life of patients in low and middle-income countries where resources for both diagnosis and treatment of such conditions are limited. In this study we investigate the impact of glaucoma on quality of life in Ethiopian patients. The quality of life of 307 glaucoma patients and 76 normal controls that were frequency matched to the age and sex profiles of the cases was assessed using Amharic version of Glaucoma Quality of Life -15 questionnaire. Linear regression models and the t-test were employed to compare significant differences in GQL-15 scores and to generate mean and mean differences between cases and controls respectively. The mean GQL-15 score in the glaucoma cases was substantially higher (indicating poorer quality of life) than the controls [cases 46.3 (95% CI, 28.8-63.8) and controls 18.6 (95% CI, 15.2-22.0), p glaucoma had significantly higher scores than the controls. Poorer quality of life was associated with age ≥ 71 years old 51.1 (95%CI, 26.2-75.9), rural residence 55.7 (95%CI, 49.9-61.5), monthly income of glaucoma (50.9; 95%CI, 43.6-58.3). These glaucoma patients, including those with normal visual acuity and early disease, had poorer quality of life compared to normal controls. Older age, rural residence, low income and more advanced disease were significantly associated with poorer quality of life. There is a need to increase awareness of the impact of glaucoma among clinicians, patients and their families, for a better understanding of the impact this disease has on a person's life.

A retrospective likelihood approach for efficient integration of multiple omics factors in case-control association studies.

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Balliu, Brunilda; Tsonaka, Roula; Boehringer, Stefan; Houwing-Duistermaat, Jeanine

2015-03-01

Integrative omics, the joint analysis of outcome and multiple types of omics data, such as genomics, epigenomics, and transcriptomics data, constitute a promising approach for powerful and biologically relevant association studies. These studies often employ a case-control design, and often include nonomics covariates, such as age and gender, that may modify the underlying omics risk factors. An open question is how to best integrate multiple omics and nonomics information to maximize statistical power in case-control studies that ascertain individuals based on the phenotype. Recent work on integrative omics have used prospective approaches, modeling case-control status conditional on omics, and nonomics risk factors. Compared to univariate approaches, jointly analyzing multiple risk factors with a prospective approach increases power in nonascertained cohorts. However, these prospective approaches often lose power in case-control studies. In this article, we propose a novel statistical method for integrating multiple omics and nonomics factors in case-control association studies. Our method is based on a retrospective likelihood function that models the joint distribution of omics and nonomics factors conditional on case-control status. The new method provides accurate control of Type I error rate and has increased efficiency over prospective approaches in both simulated and real data. © 2015 Wiley Periodicals, Inc.

Diagnostic radiography exposure increases the risk for thyroid microcarcinoma: a population-based case-control study.

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Zhang, Yawei; Chen, Yingtai; Huang, Huang; Sandler, Jason; Dai, Min; Ma, Shuangge; Udelsman, Robert

2015-09-01

Thyroid cancer incidence and diagnostic radiography exposures, particularly computed tomography (CT) scanning and nuclear medicine examinations, have increased substantially in the USA. However, very few epidemiologic studies have directly investigated their associations. A population-based case-control study was conducted in Connecticut in 2010-2011, including 462 histologically confirmed incident thyroid cancer cases and 498 population-based controls. Multivariate unconditional logistic regression models were used to estimate the associations between diagnostic radiography and the risk of thyroid cancer, controlling for potential confounding factors. Exposure to any form of diagnostic radiography was associated with an increased risk of well-differentiated thyroid microcarcinoma [tumor size≤10 mm, odds ratio (OR)=2.76, 95% confidence interval (CI): 1.31-5.81]. The highest risk increase occurred with nuclear medicine examinations (excluding cardiology tests and thyroid uptake studies; OR=5.47, 95% CI: 2.10-14.23), followed by chest CT scanning (OR=4.30, 95% CI: 1.66-11.14), head and neck CT scanning (OR=3.88, 95% CI: 1.75-8.63), upper gastrointestinal series (OR=3.56, 95% CI: 1.54-8.21), lower gastrointestinal series (OR=3.29, 95% CI: 1.41-7.66), kidney radiography involving dye injection into a vein or artery (OR=3.21, 95% CI: 1.20-8.54), mammography (OR=2.95, 95% CI: 1.14-7.61), chest radiography (OR=2.93, 95% CI: 1.37-6.29), and abdomen CT scanning (OR=2.54, 95% CI: 1.02-6.30). No significant associations were found between these imaging modalities and thyroid tumors larger than 10 mm. This study provides the first direct evidence that CT scanning and nuclear medicine examinations are associated with an increased risk of thyroid cancer. The novel finding that an array of diagnostic radiography procedures are associated with thyroid microcarcinomas warrants further investigation.

Food intake and colorectal adenomas: a case-control study in Malaysia.

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Ramadas, Amutha; Kandiah, Mirnalini

2009-01-01

It is well established that almost all colorectal cancers arise from benign, neoplastic adenomatous polyps. In previous studies, intake of fruits, vegetables and legumes were found to decrease the risk for colorectal adenomas (CRA) and colorectal cancer. This case-control study aimed to evaluate the roles of a variety of foods in contributing to the risk of CRA in Malaysian subjects. One hundred and eighteen subjects were recruited into case (n=59) and control (n=59) groups at Hospital Kuala Lumpur (HKL). A pre-tested quantitative food frequency questionnaire (FFQ) was used to record the types of food items and frequency consumed. Logistic regression was used to determine the crude and adjusted odds ratios of the independent variables. Soy bean and soy products were associated with a reduced risk for CRA (OR = 0.38, 95% CI = 0.15-0.98), while tubers were associated with increase in risk four-fold (OR = 4.14, 95% CI = 1.60-10.70) and red meat intake was found to increase the risk two and a half-fold (OR = 2.51, 95% CI = 1.02-6.28). Higher servings of fruits and vegetables were found to significantly decrease the risk (OR fruits = 0.47, 95% CI = 0.30-0.74; OR vegetables = 0.49, 95% = 0.29-0.80). In conclusion, our data support protective roles for soy, fruits and vegetables in the aetiology of colorectal adenomas and increase in risk in those with high intakes of red meat and tubers. Food intake of an individual may have an influence on one's risk for developing CRA. This finding warrants further investigation before the protective effect of these food items is to be accepted. New studies should explore the possibility of these associations among individuals in the general population especially with regard to different ethnic or other groups in Malaysia with low fruit and vegetable consumption.

National Case-Control Study of Homicide Offending and Methamphetamine Use

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Stretesky, Paul B.

2009-01-01

The purpose of this study is to examine the relationship between methamphetamine use and homicide. To carry out this study, data from the National Household Survey on Drug Abuse and Survey of Inmates in State and Federal Correctional Facilities were combined to create a case-control design. The main exposure measure is methamphetamine use and the…

Genetic susceptibility loci, environmental exposures, and Parkinson's disease: a case-control study of gene-environment interactions.

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Chung, Sun Ju; Armasu, Sebastian M; Anderson, Kari J; Biernacka, Joanna M; Lesnick, Timothy G; Rider, David N; Cunningham, Julie M; Ahlskog, J Eric; Frigerio, Roberta; Maraganore, Demetrius M

2013-06-01

Prior studies causally linked mutations in SNCA, MAPT, and LRRK2 genes with familial Parkinsonism. Genome-wide association studies have demonstrated association of single nucleotide polymorphisms (SNPs) in those three genes with sporadic Parkinson's disease (PD) susceptibility worldwide. Here we investigated the interactions between SNPs in those three susceptibility genes and environmental exposures (pesticides application, tobacco smoking, coffee drinking, and alcohol drinking) also associated with PD susceptibility. Pairwise interactions between environmental exposures and 18 variants (16 SNPs and two variable number tandem repeats, or "VNTRs") in SNCA, MAPT and LRRK2, were investigated using data from 1098 PD cases from the upper Midwest, USA and 1098 matched controls. Environmental exposures were assessed using a validated telephone interview script. Five pairwise interactions had uncorrected P-values coffee drinking × MAPT H1/H2 haplotype or MAPT rs16940806, and alcohol drinking × MAPT rs2435211. None of these interactions remained significant after Bonferroni correction. Secondary analyses in strata defined by type of control (sibling or unrelated), sex, or age at onset of the case also did not identify significant interactions after Bonferroni correction. This study documented limited pairwise interactions between established genetic and environmental risk factors for PD; however, the associations were not significant after correction for multiple testing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Inverse association between atopy and melanoma: A case-control study

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Marasigan, V. (Vivien); M.-A. Morren (Marie-Anne); J. Lambert; Medaer, K. (Karen); Fieuws, S. (Steffen); T.E.C. Nijsten (Tamar); Garmyn, M. (Marjan)

2017-01-01

textabstractHeightened cutaneous immune surveillance in atopic patients may inhibit development of melanoma. The aim of this study was to analyse the association between atopy and melanoma (development and outcome). A total of 188 cases of melanoma and 596 healthy controls were interviewed by

Knee movement patterns of injured and uninjured adolescent basketball players when landing from a jump: a case-control study.

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Louw, Quinette; Grimmer, Karen; Vaughan, Christopher

2006-03-07

A common knee injury mechanism sustained during basketball is landing badly from a jump. Landing is a complex task and requires good coordination, dynamic muscle control and flexibility. For adolescents whose coordination and motor control has not fully matured, landing badly from a jump can present a significant risk for injury. There is currently limited biomechanical information regarding the lower limb kinetics of adolescents when jumping, specifically regarding jump kinematics comparing injured with uninjured adolescents. This study reports on an investigation of biomechanical differences in landing patterns of uninjured and injured adolescent basketball players. A matched case-control study design was employed. Twenty-two basketball players aged 14-16 years participated in the study: eleven previously knee-injured and eleven uninjured players matched with cases for age, gender, weight, height and years of play, and playing for the same club. Six high-speed, three-dimensional Vicon 370 cameras (120 Hz), Vicon biomechanical software and SAS Version 8 software were employed to analyse landing patterns when subjects performed a "jump shot". Linear correlations determined functional relationships between the biomechanical performance of lower limb joints, and paired t-tests determined differences between the normalised peak biomechanical parameters. The average peak vertical ground reaction forces between the cases and controls were similar. The average peak ground reaction forces between the cases and controls were moderately correlated (r = -0.47). The control (uninjured) players had significantly greater hip and knee flexion angles and significantly greater eccentric activity on landing than the uninjured cases (p jump, at different ages and physical developmental stages, would assist clinicians and coaches to identify players with inappropriate knee performance comparable to their age or developmental stage.

Modelling and Control of HIV/AIDS Propagation - A Case Study of ...

African Journals Online (AJOL)

Modelling and Control of HIV/AIDS Propagation - A Case Study of the Ashanti Region of Ghana. ... Open Access DOWNLOAD FULL TEXT ... in the Ashanti Region of Ghana for the period 1982 to 2001 with a view to assessing the level and impact of the pandemic as well as the effectiveness of the existing control measures.

Neonatal encephalopathy and socioeconomic status: population-based case-control study.

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Blume, Heidi K; Loch, Christian M; Li, Christopher I

2007-07-01

To investigate the association between maternal socioeconomic status and the risk of encephalopathy in full-term newborns. Population-based case-control study. Washington State births from 1994 through 2002 recorded in the linked Washington State Birth Registry and Comprehensive Hospital Abstract Reporting System. Cases (n = 1060) were singleton full-term newborns with Comprehensive Hospital Abstract Reporting System International Classification of Diseases, Ninth Revision diagnoses of seizures, birth asphyxia, central nervous system dysfunction, or cerebral irritability. Control cases (n = 5330) were singleton full-term newborns selected from the same database. Main Exposures Socioeconomic status was defined by median income of the census tract of the mother's residence, number of years of maternal educational achievement, or maternal insurance status. Odds ratios estimating the risk of encephalopathy associated with disadvantaged socioeconomic status were calculated in 3 separate analyses using multivariate adjusted logistic regression. Newborns of mothers living in neighborhoods in which residents have a low median income were at increased risk of encephalopathy compared with newborns in neighborhoods in which residents have a median income more than 3 times the poverty level (adjusted odds ratio, 1.9; 95% confidence interval, 1.5-2.3). There was also a trend for increasing risk of encephalopathy associated with decreasing neighborhood income (PNewborns of mothers with less than 12 years of educational achievement had a higher risk of encephalopathy compared with newborns of mothers with more than 16 years of educational achievement (adjusted odds ratio, 1.7; 95% confidence interval, 1.3-2.3). Newborns of mothers receiving public insurance also had a higher risk of encephalopathy compared with newborns of mothers who have commercial insurance (adjusted odds ratio, 1.4; 95% confidence interval, 1.2-1.7). Disadvantaged socioeconomic status was independently

A case-control study on the association of hepatitis B virus infection and hepatocellular carcinoma in Northeast Brazil

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Cotrim Helma

1992-01-01

Full Text Available Hepatitis B virus (HBV serological markers were investigated in 40 incident cases of hepatocellular carcinoma (HCC and in two age and sex matched control groups, comprising 40 patients with other cancers and 80 healthy individuals, resident in Bahia, Brazil. Serologic tests were done by radioimmunoassay. The study observed high proportion of seropositivity to HBsAg (42.5% and of those presenting HBsAg or antiHBc (65.0% among HCC cases, higher in men than women and in those aged 17 to 30 years old. HBsAg seropositivity among HCC patients was greater than in the control group with other cancers (7.5% and in healthy controls (2.5%, corresponding to odds ratio estimates of 15.0 (95% CI 3.29, 68.30 and 33.0 (95% CI 9.13, 119.28, both statistically significant. HBeAg was not observed and antiHBe was present in 41.2% of cases, suggesting the absence of viral replication, possibly with viral DNA intergration into the hepatocyte genome. The presence of cirrhosis was associated with HBsAg seropositivity among HCC cases. A history of chronic alcoholism is shown to be more frequently related to those cases with cirrhosis. This study highlights the relevant association between HCC and HBV in Northeast Brazil, particularly for young individuals, and the high risk of development of HCC for HBsAg carriers.

OPTIMIZED REAL-TIME CONTROL OF COMBINED SEWERAGE SYSTEMS: TWO CASE STUDIES

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The paper presents results of two case studies of Real-Time Control (RTC) alternatives evaluations that were conducted on portions of sewerage systems near Paris, France and in Quebec City, Canada, respectively. The studies were performed at real-scale demonstration sites. RTC ...

Association between renal cysts and abdominal aortic aneurysm: A case-control study

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Hélio Miguel de Azevêdo Bião Veiga

Full Text Available Summary Objective: To investigate the positive association between the presence of simple renal cysts (SRCs and abdominal aortic aneurysm (AAA. Method: In a retrospective case-control study including subjects aged > 50 years, we evaluated the incidence of SRCs on computed tomography (CT scan. We compared 91 consecutive patients with AAA referred from the Division of Vascular Surgery and 396 patients without AAA, randomly selected after being matched by age and gender from 3,186 consecutive patients who underwent abdominal CT. SRC was defined as a round or oval low-attenuation lesion with a thin wall and size > 4 mm on CT without obvious evidence of radiographic enhancement or septations. Patients were considered as having AAA if the size of aorta was greater than 3.0 cm. Results: Patients with AAA and without AAA were similar in terms of age (67.9± 8.41 vs. 68.5±9.13 years (p=0.889 and gender (71.4 vs. 71.2% of male subjects, respectively (p=0.999. There was no difference in the prevalence of SRC between case and controls. Among individuals with AAA, 38 (41.8%; [95CI 32.5-52.6] had renal cysts compared to 148 (37.4%; [95CI 32.7-42.2] in the control group (p=0.473, with a prevalence ratio (PR of 1.16 (95CI 0.80-1.68. Conclusion: We found no significant differences in the prevalence of SRCs among patients with AAA and controls. Our findings suggest that the presence of SRCs is not a risk factor or a marker for AAA.

Leadership change: A case study analysis of strategy and control systems development

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Alaudin Ahmadasri

2017-01-01

Full Text Available This paper reports on how a change of leadership at the CEO-level influences strategic practices and control systems development. The case study describes how the new chief executive developed and communicated his vision and strategy through control systems and structural change. The findings indicate that senior employees’ involvement in strategic plan development (through SLT mechanism in this case brought clarity and assurance to them. Meetings are important control mechanisms to structure the sharing of information and to enhance employee commitment and help decision making. It is argued leadership manifests through the interactions of leader with employees in many control practices. The findings have implications for family-owned businesses that are facing imminent change in leadership. They benefit founders/top managers that are about to change leadership of entrepreneurial firm to the next level by highlighting the importance of preparing leader’s capacity for an effective leadership role. The study also highlights some important factors which are seldom discussed in control theories.

DHAT SYNDROME AND ITS ASSOCIATION WITH SEXUAL BEHAVIOR AND PYSCHIATRIC COMORBIDITIES IN MALES: A CASE CONTROL STUDY

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Sahu RN, Sharma VK, Ashutosh Kumar, Chintan Bavishi, Balaji More

2015-01-01

Full Text Available Background: Dhat syndrome is often taken as culture bound syndrome (CBS of Indian subcontinent. There are many misconceptions which form base of symptoms and co morbidities. Aim: Dhat syndrome is reported on basis of self diagnosis. The study aims to study associated symptoms, sexual behavior and co morbidities in Indian population. Material and Methods: This cross-sectional and case-control study was carried with help of trained local interviewers at Department of Psychiatry and Medicine, Gandhi Medical College (GMC, Associated Hamidia Hospital, Bhopal, India. Cases were compared to healthy matched controls. The study was conducted using clinical interview, physical examination and other necessary investigations like urine analysis and microscopy. Results: Of the 50 cases and control, each, age group was 21 to 25 years (48% and education upto12th class (60%. 20% cases reported history of Masturbation. Extramarital or premarital sexual contact was found to have little significance on the syndrome. 76% of the patients met DSM-IV Diagnostic Criteria for Anxiety and 56% patients met for Depression. 23 patients (46.3% were having a co-morbid somatic complains like body ache, weakness and fatigue. Erectile dysfunction by 34% & premature ejaculation by 8% was reported. In Urine routine analysis and microscope no oxalates or phosphates were noted. Conclusions: Dhat syndrome is more common among low educated young population. Laboratory evidence of any pathological cause was not found. Contrary to popular belief, it had no direct correlation with masturbation and pre and extra marital sexual contact.

The Power of Natural Selection: A Guided Investigation of Three Case Studies

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Beachly, William

2010-01-01

I describe a quantitative approach to three case studies in evolution that can be used to challenge college freshmen to explore the power of natural selection and ask questions that foster a deeper understanding of its operation and relevance. Hemochromatosis, the peppered moth, and hominid cranial capacity are investigated with a common algebraic…

Neuropsychiatric manifestation of celiac disease: A case-control study in North India

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Mahendra Nimel

2016-01-01

Full Text Available Background: Celiac disease (CD is an immune-mediated disease dependent on gluten. Prevalence of CD is about 1% and beside gastrointestinal complaints, neuropsychiatric symptoms may represent an atypical feature of CD. Some studies suggest that a gluten-free diet is effective in treating them. Settings and Design: This case-control study of 49 cases was done during the period of January to March 2013. Aim: To know the spectrum of psychiatric manifestations and cognitive functions in children with CD. Materials and Methods: We took 49 diagnosed cases of CD (based on the demonstration of IgA tissue transglutaminase antibodies and duodenal biopsy and compared with demographically matched control group (n = 50 on Seguin Form Board Test for cognitive functions and Behavioral Summarized Evaluation-Revised scale for assessment of psychiatric and behavior disturbances. All possible psychiatric diagnosis was made on the basis of International Statistical Classification of Disease and Related Health Problems-Tenth Revision criteria. Statistical Analysis: Statistical analyses were done by using Chi-square test and two-tailed P-values. Results: Neuropsychiatric manifestations were seen in 29% of cases as against 4% of controls which was statistically significant (P=0.001. Only four cases and 1 control fount to be mild mental retardation (P = 0.16. Autism, dyslexia, developmental delay, disruptive behavior disorder, and tic disorder present in cases were not found. Conclusion: Clinical manifestations of CD vary from typical malabsorption syndrome to neuropsychiatric manifestations. Those psychiatric patients who are not responding to standard pharmacological modalities, a diagnosis of CD should be taken into consideration. Only behavioral problem can be the sole clinical manifestation of CD.

Selection bias in population-based cancer case-control studies due to incomplete sampling frame coverage.

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Walsh, Matthew C; Trentham-Dietz, Amy; Gangnon, Ronald E; Nieto, F Javier; Newcomb, Polly A; Palta, Mari

2012-06-01

Increasing numbers of individuals are choosing to opt out of population-based sampling frames due to privacy concerns. This is especially a problem in the selection of controls for case-control studies, as the cases often arise from relatively complete population-based registries, whereas control selection requires a sampling frame. If opt out is also related to risk factors, bias can arise. We linked breast cancer cases who reported having a valid driver's license from the 2004-2008 Wisconsin women's health study (N = 2,988) with a master list of licensed drivers from the Wisconsin Department of Transportation (WDOT). This master list excludes Wisconsin drivers that requested their information not be sold by the state. Multivariate-adjusted selection probability ratios (SPR) were calculated to estimate potential bias when using this driver's license sampling frame to select controls. A total of 962 cases (32%) had opted out of the WDOT sampling frame. Cases age <40 (SPR = 0.90), income either unreported (SPR = 0.89) or greater than $50,000 (SPR = 0.94), lower parity (SPR = 0.96 per one-child decrease), and hormone use (SPR = 0.93) were significantly less likely to be covered by the WDOT sampling frame (α = 0.05 level). Our results indicate the potential for selection bias due to differential opt out between various demographic and behavioral subgroups of controls. As selection bias may differ by exposure and study base, the assessment of potential bias needs to be ongoing. SPRs can be used to predict the direction of bias when cases and controls stem from different sampling frames in population-based case-control studies.

IL13 genetic polymorphisms, smoking, and eczema in women: a case-control study in Japan

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Arakawa Masashi; Tanaka Keiko; Miyake Yoshihiro

2011-01-01

Abstract Background Several genetic association studies have examined the relationships between single nucleotide polymorphisms (SNPs) in the IL13 gene and eczema, and have provided contradictory results. We investigated the relationship between the IL13 SNPs rs1800925 and rs20541 and the risk of eczema in Japanese young adult women. Methods Included were 188 cases who met the criteria of the International Study of Asthma and Allergies in Childhood (ISAAC) for eczema. Control subjects were 1,...

Periodontal disease as a risk factor for adverse pregnancy outcomes: a systematic review and meta-analysis of case-control studies.

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Corbella, Stefano; Taschieri, Silvio; Francetti, Luca; De Siena, Francesca; Del Fabbro, Massimo

2012-07-01

Periodontal disease is a highly prevalent group of illnesses of microbial etiology, whose consequence is a severe breakdown of tooth-supporting structures. A link between periodontal infection and several systemic conditions, among which adverse pregnancy outcomes, has been suggested in the recent years. The aim of this review based on case-control studies was to evaluate if periodontal disease could be considered as a risk factor for preterm birth, low birth-weight and preterm low birth-weight. An electronic search (via Pubmed) was performed for case-control studies investigating the relationship between periodontal disease and adverse pregnancy outcomes. From the initially retrieved 417 articles, 17 case-control studies, accounting for a total of 10,148 patients, were included in the review and in the meta-analysis. The estimated odds ratio was 1.78 (CI 95%: 1.58, 2.01) for preterm birth, 1.82 (CI 95%: 1.51, 1.20) for low birth-weight and 3.00 (CI 95%: 1.93, 4.68) for preterm low birth-weight. Despite the results of the analysis of pooled data suggested a link between periodontal diseases and adverse pregnancy outcomes, the presence of important confounders, whose effect could not be addressed, prevents a validation of the meta-analysis outcomes. Further more accurate investigations based on individual data analysis could give a better insight into the topic of the present review.

Modifiable lifestyle factors associated with osteoporosis in Korean men: a case-control study.

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Park, Kye-Yeung; Hwang, Hwan-Sik; Park, Hoon-Ki

2017-12-01

The prevention, education, and treatment of osteoporosis are all recognized as important components in men as well as women. This study revealed that the lifestyle factors associated with male osteoporosis included being underweight and being a current smoker. Being overweight or obese and having a regular exercise habit were negatively associated with male osteoporosis. Osteoporosis is a significant health problem in Korea and worldwide. Although osteoporosis is less prevalent in males than in females, the fracture-related mortality rate is higher in males than in females. The aim of this study was to investigate the relationship of modifiable lifestyle factors in males with osteoporosis. A case-control study was performed in men who visited a single university hospital for a medical check-up between August 2003 and July 2016. Patients were classified in the case group according to the World Health Organization (WHO) Osteoporosis Criteria. The control group was created by matching patients according to age and check-up date. Lifestyle factors were evaluated by a self-assessment questionnaire. Multivariate conditional logistic regression was used to examine the association between lifestyle factors and male osteoporosis with age stratification at 50 years. A total of 1304 subjects were included in this analysis, 326 of whom were in the case group and 978 of whom were in the control group. Within their age group, subjects with osteoporosis were more often underweight (odds ratio [OR] = 2.35, 95% confidence interval [CI], 1.11-4.98) or more often current smokers (2.22, 1.50-3.28) than control subjects. The subjects who were overweight (0.45, 0.32-0.64), obese (0.19, 0.13-0.27), had an irregular exercise habit (0.64, 0.43-0.94), or had a regular exercise habit (0.40, 0.28-0.57) were more likely to have normal bone status. Alcohol drinking habit had no significant association with male osteoporosis. Several modifiable lifestyle factors were associated with male

Case Control Study of Impulsivity, Aggression, Pesticide Exposure and Suicide Attempts Using Pesticides among Farmers.

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Lyu, Chun Ping; Pei, Jian Ru; Beseler, L Cheryl; Li, Yu Ling; Li, Jian Hui; Ren, Ming; Stallones, Lorann; Ren, Shu Ping

2018-03-01

A case-control study was conducted to investigate associations between organophosphate pesticide (OP) exposure, aggression, impulsivity, and attempted suicide. Questionnaires were used to collect information; impulsivity and aggression were measured by the Barratt Impulsivity Scale (BIS) and the Aggression Inventory (AI). A greater number of OP symptoms was associated with an increased odds of a suicide attempt after adjusting for marital status and income (OR = 1.45; CI 1.14-1.86). Attempted suicide was significantly associated with high impulsivity scores (means: 72.4 vs. 60.6, P controls and scored higher on scales of impulsivity and aggression. Copyright © 2018 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Study of environmental and genetic factors in children with craniosynostosis: A case-control study

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Barik, Mayadhar; Bajpai, Minu; Das, Rashmi Ranjan; Panda, Shasanka Shekhar

2013-01-01

Background: Craniosynostosis is a congenital defect that causes one or more sutures on an infant's skull to close earlier than normal. Though both genetic and environmental factors play a role in its pathogenesis, there is no published Indian data to verify this. Materials and Methods: In this case-control study, we investigated the association of craniosynostosis with parental age in 50 children with craniosynostosis attending the surgical outpatient department of a tertiary care institution in North India. Results: There was a significant association of craniosynostosis with advanced parental [OR 2.17 (95% CI 1.08 to 4.36)] but not maternal age. Education status of parents also revealed that those having a higher education had an increased risk of having a child with craniosynostosis [maternal education, OR 2.32 (95% CI 1.2 to 4.76); paternal education, OR 2.51 (95% CI 1.21 to 5.0)]. Molecular analysis by sequencing confirmed following amino-acid substitution in different Exons of the FGFR2 gene. Besides these, we found other novel identical mutations in FGFR2 gene in both syndromic and non-syndromic craniosynostoses. Conclusion: This is the first epidemiological study in India that provides evidence that, advanced paternal age and higher parental education level might be associated with an increased risk of craniosynostosis. New mutations were identified in cases of both syndromic and non-syndromic craniosynostosis. PMID:24082921

Childhood risk factors in Korean women with anorexia nervosa: two sets of case-control studies with retrospective comparisons.

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Kim, Youl-Ri; Heo, Si Young; Kang, Heechan; Song, Ki Jun; Treasure, Janet

2010-11-01

The aim of this study was to investigate the characteristics of the risk factors for anorexia nervosa (AN) in Korean women. Two sets of case-control comparisons were conducted, in which 52 women with lifetime AN from Seoul, S. Korea, were compared with 108 Korean healthy controls and also with 42 women with lifetime AN from the UK in terms of their childhood risk factors. A questionnaire designed to conduct a retrospective assessment of the childhood risk factors was administered to all participants. The Korean AN women were more likely to report premorbid anxiety, perfectionism, and emotional undereating and were less likely to report having supportive figures in their childhood than the Korean healthy controls. There were no overall differences in the childhood risk factors between the Korean and British women with AN. Premorbid anxiety, perfectionism, less social support, and emotional undereating merit attention as risk factors in Korean AN. The current results are informative, but an epidemiologically robust prospective case-control study would be needed to validate these findings. © 2009 by Wiley Periodicals, Inc.

Statistical process control using optimized neural networks: a case study.

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Addeh, Jalil; Ebrahimzadeh, Ata; Azarbad, Milad; Ranaee, Vahid

2014-09-01

The most common statistical process control (SPC) tools employed for monitoring process changes are control charts. A control chart demonstrates that the process has altered by generating an out-of-control signal. This study investigates the design of an accurate system for the control chart patterns (CCPs) recognition in two aspects. First, an efficient system is introduced that includes two main modules: feature extraction module and classifier module. In the feature extraction module, a proper set of shape features and statistical feature are proposed as the efficient characteristics of the patterns. In the classifier module, several neural networks, such as multilayer perceptron, probabilistic neural network and radial basis function are investigated. Based on an experimental study, the best classifier is chosen in order to recognize the CCPs. Second, a hybrid heuristic recognition system is introduced based on cuckoo optimization algorithm (COA) algorithm to improve the generalization performance of the classifier. The simulation results show that the proposed algorithm has high recognition accuracy. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Consanguineous marriage and increased risk of idiopathic congenital talipes equinovarus: a case-control study in a rural area.

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Sahin, Orcun; Yildirim, Cengiz; Akgun, Rahmi C; Haberal, Bahtiyar; Yazici, Ayse C; Tuncay, Ismail C

2013-01-01

The purpose of this study is to evaluate if there is any relationship between consanguineous marriages and idiopathic congenital talipes equinovarus (CTEV). A case-control study on CTEV screening was conducted in a rural eastern city of Turkey between 2009 and 2011 and a total of 28 cases (infants with idiopathic CTEV) and 575 controls (healthy infants) were recruited. Sociodemographic status of the infants, including gestational age and birth weights, maternal characteristics and, if any, the degree of consanguinity, were recorded. As an inclusion criterion, only singleton, full-term, live births were accepted. A backward stepwise logistic regression model was used to evaluate the relationship between idiopathic CTEV and parental consanguinity. Unadjusted and adjusted odds ratios (OR) with 95% confidence interval (CI) were calculated. Among maternal and infant characteristics, significant risk factors for idiopathic CTEV in the regression analysis were work status (employed), consanguineous marriage, sex (male), and gestational age (>42 wk). Babies born to first-cousin parents had >4 times the risk of idiopathic CTEV [OR, 4.138, (95% CI, 1.484, 11.538)] and the risk for those born to distant relatives was 2.9 times higher [OR, 2.941, (95% CI, 1.070, 8.087)] than for children of unrelated parents. Consanguineous marriage was significantly associated with an increased risk of idiopathic CTEV. This association remained significant even after adjusting for potential confounding variables. To obtain more accurate results, a population-based screening study with an increased number of cases and controls should be performed in future studies. Case-control study investigating the effect of a patient characteristic on the outcome of disease (level-III).

Determinants of Internet Addiction among Adolescents: A Case-Control Study

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Artemis Tsitsika

2011-01-01

Full Text Available Internet Addiction (IA is associated with adverse psychosocial development and mental disorders. The study aims were to evaluate the psychosocial profiles and psychiatric comorbidities associated with IA among adolescents. A case-control study was conducted among 129 adolescents in the outpatient setting of the Adolescent Health Unit of the Second University Department of Pediatrics in Athens, Greece. The case group consisted of 86 adolescents with IA as evaluated following psychiatric interview with two independent examiners. The control group consisted of 43 adolescents without IA, frequency matched for age and gender with case group participants. The study findings indicated that adolescents with IA were significantly more likely to have divorced parents (p = 0.012 and/or dysfunctional familial relationships (p < 0.0001. The proportion of adolescents with poor academic performance (p < 0.0001 and unexcused school absences (p = 0.004 was greater among those with IA. Moreover, approximately two-thirds of the adolescents with IA were engaged in high-risk behaviors (p < 0.0001. Finally, adolescents with IA were 3.89 times more likely to present with comorbid psychiatric conditions (CI 95%: 1.19–12.70, including depression (10.5 vs. 0%; p = 0.022. Adolescent IA is associated with deterred familial functions, poor academic performance, engagement in high-risk behaviors, and an augmented likelihood for depression.

Perinatal mortality and associated risk factors: a case control study ...

African Journals Online (AJOL)

BACKGROUND: Perinatal mortality is reported to be five times higher in developing than in developed nations. Little is known about the commonly associated risk factors for perinatal mortality in Southern Nations National Regional State of Ethiopia. METHODS: A case control study for perinatal mortality was conducted in ...

Internet-based control recruitment for a case-control study of major risk factors for stroke in Korea: lessons from the experience.

Science.gov (United States)

Park, Jong-Moo; Cho, Yong-Jin; Lee, Kyung Bok; Park, Tai Hwan; Lee, Soo Joo; Han, Moon-Ku; Ko, Youngchai; Lee, Jun; Cha, Jae-Kwan; Lee, Byung-Chul; Yu, Kyung-Ho; Oh, Mi-Sun; Lee, Ji Sung; Lee, Juneyoung; Bae, Hee-Joon

2014-01-01

This study aimed to estimate the population-attributable risks (PARs) of 9 major risk factors for stroke in Korea through a case-control study and to test the feasibility and validity of internet-based control recruitment. From April 2008 to September 2009, controls were enrolled via internet after providing consent for participation through a web-based survey. The cases included patients who were admitted to the participating centers due to acute stroke or transient ischemic attack within 7 days of onset during the study period. Each control was age- and sex-matched with 2 cases. Adjusted odd ratios, age-standardized prevalence, and PARs were estimated for the 9 major risk factors using the prevalence of risk factors in the control group and the age and sex characteristics from Korea's national census data. In total, 1041 controls were matched to 2082 stroke cases. Because of a shortage of elderly controls in the internet-based recruitment, 248 controls were recruited off-line. The PARs were 23.44%, 10.95%, 51.32%, and 6.35% for hypertension, diabetes, smoking, and stroke history, respectively. Hypercholesterolemia, atrial fibrillation, obesity, coronary heart disease, and a family history of stroke were not associated with stroke. Comparison with education and religion of the control group with that mentioned in the national census data showed a notable difference. The study results imply that internet-based control recruitment for a case-control study requires careful selection of risk factors with high self-awareness and effective strategies to facilitate the recruitment of elderly participants. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Residents in difficulty—just slower learners? A case-control study

DEFF Research Database (Denmark)

O'Neill, Lotte; Norberg, Karen; Thomsen, Maria

2014-01-01

were matched for graduation year. Medical school exam failures, grades, completion time, and academic dispensations as predictors of case status were examined with conditional logistic regression. RESULTS In total 89 cases and 343 controls were identified. The total number of medical school re......-examinations and the time it took to complete medical school were significant individual predictors of subsequent difficulties (deceleration, transferral or dropout) in residency whereas average medical school grades were not. CONCLUSIONS Residents in difficulty eventually reached similar competence levels as controls...... during medical school; however, they needed more exam attempts and longer time to complete their studies, and so seemed to be slower learners. A change from “fixed-length variable-outcome programmes” to “fixed-outcome variable-length programmes” has been proposed as a way of dealing with the fact...

Case studies in control putting theory to work

CERN Document Server

Juričić, Đani

2013-01-01

Case Studies in Control presents a framework to facilitate the use of advanced control concepts in real systems based on two decades of research and over 150 successful applications for industrial end-users from various backgrounds. In successive parts the text approaches the problem of putting the theory to work from both ends, theoretical and practical. The first part begins with a stress on solid control theory and the shaping of that theory to solve particular instances of practical problems. It emphasizes the need to establish by experiment whether a model-derived solution will perform properly in reality. The second part focuses on real industrial applications based on the needs and requirements of end-users. Here, the engineering approach is dominant but with theoretical input of varying degree depending on the particular process involved. Following the illustrations of the progress that can be made from either extreme of the well-known theory–practice divide, the text proceeds to a third part relate...

The Relationship between Food Intake and Bladder Cancer: A Case Control Study

Directory of Open Access Journals (Sweden)

2015-01-01

Full Text Available Background & aim: Bladder cancer is the second most common cancer of the urinary tract worldwide and the third most common cancer among Iranian males. Despite the relative high incidence of bladder cancer in Iran, no study has examined the relationship between dietary factors and bladder cancer. The aim of the present study was to investigate this relationship. Methods: The present case-control study was carried out on fifty-five patients with bladder cancer and including 110 cancer-free patients as controls. Dietary intake was evaluated using a food frequency questionnaire. To investigate the relationship between food items and bladder cancer, the subjects were classified according to the tertile of food items. The odds ratio was calculated for each tertile and the first tertile was considered as the reference group. Results: Our findings revealed that among food groups, animal fat (OR=19.76, fat (OR=12.92, junk foods (OR=8.1, organ meat (OR=5.47, processed meat (OR=5.34 and sweets (OR=3.62 were involved in the development of bladder cancer. In bladder carcinogenesis, an inverse association was recorded between consumption of low fat dairy products (OR=0.31, yoghurt (OR =0.14, fish (OR = 0.13, specific fruits (OR=0.13 and the development of bladder cancer. Conclusion: Animal products and sources of saturated fat are associated with an increased in risk of bladder cancer. The protective effect of olive oil, specific fruits, vegetables, low-fat dairy fermented was observed to reduce the risk of bladder cancer.

Case-control study on infant mortality in Southern Brazil

Directory of Open Access Journals (Sweden)

Mendes Karina Giane

2006-01-01

Full Text Available OBJECTIVE: To identify risk factors associated with infant mortality and, more specifically, with neonatal mortality. METHODS: A case-control study was carried out in the municipality of Caxias do Sul, Southern Brazil. Characteristics of prenatal care and causes of mortality were assessed for all live births in the 2001-2002 period with a completed live-birth certificate and whose mothers lived in the municipality. Cases were defined as all deaths within the first year of life. As controls, there were selected the two children born immediately after each case in the same hospital, who were of the same sex, and did not die within their first year of life. Multivariate analysis was performed using conditional logistic regression. RESULTS: There was a reduction in infant mortality, the greatest reduction was observed in the post-neonatal period. The variables gestational age (<36 weeks, birth weight (<2,500 g, and 5-minute Apgar (<6 remained in the final model of the multivariate analysis, after adjustment. CONCLUSIONS: Perinatal conditions comprise almost the totality of neonatal deaths, and the majority of deaths occur at delivery. The challenge for reducing infant mortality rate in the city is to reduce the mortality by perinatal conditions in the neonatal period.

Organohalogen body burdens in a breast cancer case-control study

Energy Technology Data Exchange (ETDEWEB)

Petreas, M.; She, J.; Visita, P.; Winkler, J. [Hazardous Materials Lab., California Dept. of Toxic Substances Control, Berkeley, CA (United States); Hurley, S.; Smith, D.; Reynolds, P. [Environmental Health Investigations Branch, California Dept. of Health Services, Oakland, CA (United States); Jeffrey, S.; Mahoney, E. [Dept. of Surgery, Stanford Univ. School of Medicine, Stanford, CA (United States)

2004-09-15

Due to their lipophilic properties, dioxins (PCDD/PCDFs) and other organohalogen compounds bioaccumulate in the food chain, with diet accounting for over 90% of non-occupational exposures. To date, few epidemiologic studies have examined the relationship between dioxins and breast cancer in human populations. Most have examined risks in occupational cohorts or in populations exposed to dioxins from the Seveso accident6-8. Results from these studies have been conflicting and have largely been limited by a lack of individual-level measures of exposure, small numbers of cases, and inability to account for established breast cancer risk factors. Very little is known about the potential health effects of low-level environmental dioxin contamination. We present data on PCDD/PCDFs, organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in adipose tissues of women participating in a breast cancer case-control study centered in the San Francisco Bay Area. In addition, we examine distributions of these chemicals in breast and abdominal adipose of women undergoing mastectomies with concurrent breast reconstruction. If concentrations were equivalent, use of abdominal adipose would greatly enhance the pool for controls for future epidemiological studies.

Intrahousehold resource allocation and child growth in Mozambique: an ethnographic case-control study.

Science.gov (United States)

Pfeiffer, J; Gloyd, S; Ramirez Li, L

2001-07-01

This study examines the effect of intrahousehold cash income control and decision-making patterns on child growth in the rural town of Sussundenga in Manica Province, Mozambique. A case-control study design was used to examine the influence of men's and women's disaggregated cash incomes on child growth. The research tested whether greater maternal share of household cash income was associated with (1) increased maternal decision-making and bargaining power in the household, and (2) better child growth. Fifty case households, with children 1-4 years old exhibiting poor growth, were matched with 50 control households of similar socioeconomic status in which all children under five demonstrated healthy growth. Data were gathered on gender-specific income generation and expenditure, specific intrahousehold allocation processes, diet, and sociodemographic variables using a formal survey. Key informant interviews, focus groups, and observation over one year provided ethnographic context for the case-control findings. Case-control differences were analyzed using McNemar's test, paired t-test, and conditional logistic regression. In spite of matching households for socioeconomic status, control household incomes were still slightly greater than cases. Male spouse income was also higher among controls while maternal income, and maternal proportion of household income, were not significantly different. Household meat, fish and poultry consumption, and maternal education were significantly greater among control households than cases. Greater maternal share of household income was not associated with greater maternal decision-making around cash. However, mothers must spend what little cash they earn on daily food supplies and usually request additional cash from spouses to cover these costs. There is evidence that if mothers earn enough to cover these socially prescribed costs, they can spend cash for other needs. Above this threshold, women's earnings may confer more

Helicobacter pylori infection, chronic corpus atrophic gastritis and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort: A nested case-control study.

Science.gov (United States)

Huang, Jiaqi; Zagai, Ulrika; Hallmans, Göran; Nyrén, Olof; Engstrand, Lars; Stolzenberg-Solomon, Rachael; Duell, Eric J; Overvad, Kim; Katzke, Verena A; Kaaks, Rudolf; Jenab, Mazda; Park, Jin Young; Murillo, Raul; Trichopoulou, Antonia; Lagiou, Pagona; Bamia, Christina; Bradbury, Kathryn E; Riboli, Elio; Aune, Dagfinn; Tsilidis, Konstantinos K; Capellá, Gabriel; Agudo, Antonio; Krogh, Vittorio; Palli, Domenico; Panico, Salvatore; Weiderpass, Elisabete; Tjønneland, Anne; Olsen, Anja; Martínez, Begoña; Redondo-Sanchez, Daniel; Chirlaque, Maria-Dolores; Hm Peeters, Petra; Regnér, Sara; Lindkvist, Björn; Naccarati, Alessio; Ardanaz, Eva; Larrañaga, Nerea; Boutron-Ruault, Marie-Christine; Rebours, Vinciane; Barré, Amélie; Bueno-de-Mesquita, H B As; Ye, Weimin

2017-04-15

The association between H. pylori infection and pancreatic cancer risk remains controversial. We conducted a nested case-control study with 448 pancreatic cancer cases and their individually matched control subjects, based on the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, to determine whether there was an altered pancreatic cancer risk associated with H. pylori infection and chronic corpus atrophic gastritis. Conditional logistic regression models were applied to calculate odds ratios (ORs) and corresponding 95% confidence intervals (CIs), adjusted for matching factors and other potential confounders. Our results showed that pancreatic cancer risk was neither associated with H. pylori seropositivity (OR = 0.96; 95% CI: 0.70, 1.31) nor CagA seropositivity (OR = 1.07; 95% CI: 0.77, 1.48). We also did not find any excess risk among individuals seropositive for H. pylori but seronegative for CagA, compared with the group seronegative for both antibodies (OR = 0.94; 95% CI: 0.63, 1.38). However, we found that chronic corpus atrophic gastritis was non-significantly associated with an increased pancreatic cancer risk (OR = 1.35; 95% CI: 0.77, 2.37), and although based on small numbers, the excess risk was particularly marked among individuals seronegative for both H. pylori and CagA (OR = 5.66; 95% CI: 1.59, 20.19, p value for interaction cancer risk in western European populations. However, the suggested association between chronic corpus atrophic gastritis and pancreatic cancer risk warrants independent verification in future studies, and, if confirmed, further studies on the underlying mechanisms. © 2016 UICC.

Experience gained with a case control study of risk factors in bronchial carcinoma - would the approach be suitable for assessment of the radon problem?

International Nuclear Information System (INIS)

Wichmann, H.E.

1988-01-01

In the USA and in Sweden, case control studies are being done for investigating the incidence of lung cancer and a possible association with indoor exposure to radon daughters. In the F.R.G., methods and results of a case control study of other risk factors in bronchial carcinoma are available, and the question currently discussed is whether the data obtained by this study, together with additional measurements, could be used to assess the radon problem, or whether an individual radon study should be done, and what its requirements would be. (orig.) [de

Risk factors for syphilis in women: case-control study

Directory of Open Access Journals (Sweden)

Vilma Costa de Macêdo

2017-08-01

Full Text Available ABSTRACT OBJECTIVE To determine the sociodemographic, behavioral, and health care factors related to the occurrence of syphilis in women treated at public maternity hospitals. METHODS This is a case-control study (239 cases and 322 controls with women admitted to seven maternity hospitals in the municipality of Recife, Brazil, from July 2013 to July 2014. Eligible women were recruited after the result of the VDRL (Venereal Disease Research Laboratory under any titration. The selection of cases and controls was based on the result of the serology for syphilis using ELISA (enzyme-linked immunosorbent assay. The independent variables were grouped into: sociodemographic, behavioral, clinical and obstetric history, and health care in prenatal care and maternity hospital. Information was obtained by interview, during hospitalization, with the application of a questionnaire. Odds ratios and 95% confidence intervals were estimated using logistic regression to identify the predicting factors of the variable to be explained. RESULTS The logistic regression analysis identified as determinant factors for gestational syphilis: education level of incomplete basic education or illiterate (OR = 2.02, lack of access to telephone (OR = 2.4, catholic religion (OR = 1.70 , four or more pregnancies (OR = 2.2, three or more sexual partners in the last year (OR = 3.1, use of illicit drugs before the age of 18 (OR = 3.0, and use of illicit drugs by the current partner (OR = 1.7. Only one to three prenatal appointments (OR = 3.5 and a previous history of sexually transmitted infection (OR = 9.7 were also identified as determinant factors. CONCLUSIONS Sociodemographic, behavioral, and health care factors are associated with the occurrence of syphilis in women and should be taken into account in the elaboration of universal strategies aimed at the prevention and control of syphilis, but with a focus on situations of greater vulnerability.

Risk factors for syphilis in women: case-control study

Science.gov (United States)

de Macêdo, Vilma Costa; de Lira, Pedro Israel Cabral; de Frias, Paulo Germano; Romaguera, Luciana Maria Delgado; Caires, Silvana de Fátima Ferreira; Ximenes, Ricardo Arraes de Alencar

2017-01-01

ABSTRACT OBJECTIVE To determine the sociodemographic, behavioral, and health care factors related to the occurrence of syphilis in women treated at public maternity hospitals. METHODS This is a case-control study (239 cases and 322 controls) with women admitted to seven maternity hospitals in the municipality of Recife, Brazil, from July 2013 to July 2014. Eligible women were recruited after the result of the VDRL (Venereal Disease Research Laboratory) under any titration. The selection of cases and controls was based on the result of the serology for syphilis using ELISA (enzyme-linked immunosorbent assay). The independent variables were grouped into: sociodemographic, behavioral, clinical and obstetric history, and health care in prenatal care and maternity hospital. Information was obtained by interview, during hospitalization, with the application of a questionnaire. Odds ratios and 95% confidence intervals were estimated using logistic regression to identify the predicting factors of the variable to be explained. RESULTS The logistic regression analysis identified as determinant factors for gestational syphilis: education level of incomplete basic education or illiterate (OR = 2.02), lack of access to telephone (OR = 2.4), catholic religion (OR = 1.70 ), four or more pregnancies (OR = 2.2), three or more sexual partners in the last year (OR = 3.1), use of illicit drugs before the age of 18 (OR = 3.0), and use of illicit drugs by the current partner (OR = 1.7). Only one to three prenatal appointments (OR = 3.5) and a previous history of sexually transmitted infection (OR = 9.7) were also identified as determinant factors. CONCLUSIONS Sociodemographic, behavioral, and health care factors are associated with the occurrence of syphilis in women and should be taken into account in the elaboration of universal strategies aimed at the prevention and control of syphilis, but with a focus on situations of greater vulnerability. PMID:28832758

Control selection and confounding factors: A lesson from a Japanese case-control study to examine acellular pertussis vaccine effectiveness.

Science.gov (United States)

Ohfuji, Satoko; Okada, Kenji; Nakano, Takashi; Ito, Hiroaki; Hara, Megumi; Kuroki, Haruo; Hirota, Yoshio

2017-08-24

When using a case-control study design to examine vaccine effectiveness, both the selection of control subjects and the consideration of potential confounders must be the important issues to ensure accurate results. In this report, we described our experience from a case-control study conducted to evaluate the effectiveness of acellular pertussis vaccine combined with diphtheria-tetanus toxoids (DTaP vaccine). Newly diagnosed pertussis cases and age- and sex-matched friend-controls were enrolled, and the history of DTaP vaccination was compared between groups. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of vaccination for development of pertussis. After adjustment for potential confounders, four doses of DTaP vaccination showed a lower OR for pediatrician-diagnosed pertussis (OR=0.11, 95% CI, 0.01-0.99). In addition, the decreasing OR of four doses vaccination was more pronounced for laboratory-confirmed pertussis (OR=0.07, 95%CI, 0.01-0.82). Besides, positive association with pertussis was observed in subjects with a history of steroid treatment (OR=5.67) and those with a recent contact with a lasting cough (OR=4.12). When using a case-control study to evaluate the effectiveness of vaccines, particularly those for uncommon infectious diseases such as pertussis, the use of friend-controls may be optimal due to the fact that they shared a similar experience for exposure to the pathogen as the cases. In addition, to assess vaccine effectiveness as accurately as possible, the effects of confounding should be adequately controlled with a matching or analysis technique. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Risk of intracerebral hemorrhage associated with phenprocoumon exposure: a nested case-control study in a large population-based German database.

Science.gov (United States)

Behr, Sigrid; Andersohn, Frank; Garbe, Edeltraut

2010-07-01

Intracerebral hemorrhage (ICH) is the most serious complication of oral anticoagulation. This study investigated the risk of ICH for phenprocoumon which is the most widely used oral anticoagulant in Germany. We conducted a nested case-control study in a cohort of 13.4 million insurants of 4 German statutory health insurances (SHIs) who were continuously enrolled for 6 months prior to cohort entry. Cases were patients hospitalized for ICH. Ten controls were matched to each case by SHI, birth year, and sex using incidence density sampling. Rate ratios (RR) of ICH for current phenprocoumon use as compared to non-use were estimated from odds ratios calculated by conditional logistic regression analyses considering multiple risk factors. Analysis of the full cohort revealed a strong increase in incidence of ICH with increasing age. In the nested case-control study including 8138 cases of ICH and 81,373 matched controls, we observed an increased risk of ICH for current phenprocoumon exposure that varied with age. The phenprocoumon-associated risk of ICH was lower in older age groups with RRs from 4.20 (95% confidence interval (CI) 2.44-7.21) for phenprocoumon users less than 55 years of age to 2.43 (95%CI, 1.81-3.27) for those older than 85 years. Our study confirmed known risk factors of ICH. Phenprocoumon exposure was associated with an increased risk of ICH. The interaction of risk for phenprocoumon with age was unexpected and needs further study. (c) 2010 John Wiley & Sons, Ltd.

Birth outcomes of cases with isolated atrial septal defect type II--a population-based case-control study.

Science.gov (United States)

Vereczkey, Attila; Kósa, Zsolt; Csáky-Szunyogh, Melinda; Urbán, Róbert; Czeizel, Andrew E

2013-07-01

In general, epidemiological studies have evaluated cases with congenital cardiovascular abnormalities together. The aim of this study is to describe the birth outcomes of cases with isolated/single atrial septal defect type II (ASD-II, i.e. only a fossa ovalis defect) after surgical correction or lethal outcome in the light of maternal sociodemographic data. Comparison of birth outcomes and maternal characteristics of cases with ASD-II and controls without defect. The population-based Hungarian Case-Control Surveillance of Congenital Abnormalities. Hungarian newborn infants with or without ASD-II. Medically recorded birth outcomes, maternal age and birth order were evaluated. Marital and employment status was based on maternal information. The lifestyle factors were analyzed in a subsample of mothers visited at home based on a personal interview with mothers and their close relatives, and the family consensus was accepted. Mean gestational age at delivery and birthweight, rate of preterm birth and low birthweight, maternal age, birth order, marital and employment status. The evaluation of 471 cases with ASD-II and 38,151 controls without any defects showed a female excess in cases with ASD-II, having shorter gestational age and lower mean birthweight, and thus a higher rate of preterm births and low birthweight. Intrauterine growth restriction and shorter gestational age were found in cases with ASD-II, particularly in female children. These factors may have a general developmental process in which there was not closure of the foramen ovale, thus echocardiographic screening of these babies might be of value. © 2012 The Authors Acta Obstetricia et Gynecologica Scandinavica © 2012 Nordic Federation of Societies of Obstetrics and Gynecology.

Effectiveness of inactivated quadrivalent influenza vaccine in the 2015/2016 season as assessed in both a test-negative case-control study design and a traditional case-control study design.

Science.gov (United States)

Kimiya, Takahisa; Shinjoh, Masayoshi; Anzo, Makoto; Takahashi, Hiroki; Sekiguchi, Shinichiro; Sugaya, Norio; Takahashi, Takao

2018-04-21

Both traditional case-control studies (TCCSs) and test-negative case-control studies (TNCCSs) are commonly used to assess influenza vaccine effectiveness (VE). To compensate for the fact that observational studies are susceptible to bias, we combined both methods to assess VE in one geographical area during the 2015/2016 season, when influenza A (H1N1)pdm was dominant. Our TNCCS covered 331 children aged 6 months to 15 years who visited our hospital with fever, including 182 with influenza, and our TCCS covered 812 pediatric outpatients aged 6 months to 15 years, including 214 with influenza. Influenza infection and vaccination history were reviewed, and VE was calculated as (1 - odds ratio) × 100. In the TNCCS, VE against influenza A was 68% (95% CI 47-81) overall, and 70% (48-83) for those given two doses; against influenza B, VE was 37% (- 12-64) overall and 49% (2-74) for two doses. In the TCCS, VE against influenza A was 44% (15-63) overall and 44% (13-64) for two doses, and VE against influenza B was 24% (- 19-52) overall and 41% (3-64) for two doses. Both studies confirmed significant VE against influenza A, significant two-dose VE against influenza B, and better two-dose VE than one-dose VE. What is Known: • Influenza vaccine effectiveness (VE) varies from year to year. • Observational studies are conventionally used for VE assessment. However, they are inherently susceptible to bias and confounding. What is New: • This is the first report of influenza VE assessment using more than one observational study and performed in a specific area during the same season. • VE estimates obtained in our traditional case-control study were lower than those in our test-negative case-control study, but both studies found significant VE against influenza.

Risk of Psoriasis Following Terbinafine or Itraconazole Treatment for Onychomycosis: A Population-Based Case-Control Comparative Study.

Science.gov (United States)

Chiu, Hsien-Yi; Chang, Wei-Lun; Tsai, Tsen-Fang; Tsai, Yi-Wen; Shiu, Ming-Neng

2018-03-01

Several case studies have reported an association between antifungal drug use and psoriasis risk. The objective of this study was to investigate the association between terbinafine/itraconazole exposure and psoriasis incidence. Among patients with onychomycosis in the Taiwan National Health Insurance Research Database, 3831 incident psoriasis cases were identified during 2004-2010 and compared with 3831 age- and sex-matched controls with the same look-back period. Multivariate conditional logistic regression was used for the analysis. The psoriasis cases were significantly more likely than matched controls to have used terbinafine or itraconazole (59.85 vs. 42.70%, respectively; p terbinafine/itraconazole use was associated with an increased psoriasis risk (adjusted odds ratio 1.33, 95% confidence interval 1.15-1.54). The association was stronger for more recent drug exposure (adjusted odds ratio 2.96, 95% confidence interval 2.25-3.90 for ≤ 90 days before the sampling date; adjusted odds ratio 1.04, 95% confidence interval 0.89-1.22 for > 360 days). In a comparison of patients receiving terbinafine or itraconazole only, psoriasis risk was higher for itraconazole (adjusted odds ratio 1.21, 95% confidence interval 1.05-1.40). This large population-based case-control analysis showed that exposure to terbinafine or itraconazole is associated with an increased risk of incident psoriasis. The finding of an increased psoriasis risk for antifungal drug users, particularly for itraconazole, deserves attention in clinical practice although further prospective studies are necessary to confirm our findings and clarify the biological mechanisms that underlie these associations.

Risk factors for Creutzfeldt-Jakob disease: a reanalysis of case-control studies.

NARCIS (Netherlands)

D.P.W.M. Wientjens (Dorothee); Z. Davanipour; K. Kondo; W.B. Matthews; R.G. Will (Robert); C.M. van Duijn (Cornelia); A. Hofman (Albert)

1996-01-01

textabstractTo review the evidence for risk factors of Creutzfeldt-Jakob disease (CJD), we pooled and reanalyzed the raw data of three case-control studies. The pooled data set comprised 178 patients and 333 control subjects. The strength of association between CJD and putative risk factors was

Smoking, alcohol, and coffee consumption preceding Parkinson's disease: a case-control study.

Science.gov (United States)

Benedetti, M D; Bower, J H; Maraganore, D M; McDonnell, S K; Peterson, B J; Ahlskog, J E; Schaid, D J; Rocca, W A

2000-11-14

To study the association of PD with preceding smoking, alcohol, and coffee consumption using a case-control design. The authors used the medical records linkage system of the Rochester Epidemiology Project to identify 196 subjects who developed PD in Olmsted County, MN, during the years 1976 to 1995. Each incident case was matched by age (+/-1 year) and sex to a general population control subject. The authors reviewed the complete medical records of cases and control subjects to abstract exposure information. For coffee consumption, the authors found an OR of 0.35 (95% CI = 0.16 to 0.78, p = 0.01), a dose-effect trend (p = 0.003), and a later age at PD onset in cases who drank coffee compared with those who never did (median 72 versus 64 years; p = 0.0002). The inverse association with coffee remained significant after adjustment for education, smoking, and alcohol drinking and was restricted to PD cases with onset at age coffee drinking and PD; however, this association does not imply that coffee has a direct protective effect against PD. Alternative explanations for the association should be considered.

Vitamin D and Fracture Risk in Early Childhood: A Case-Control Study

Science.gov (United States)

Anderson, Laura N.; Heong, Sze Wing; Chen, Yang; Thorpe, Kevin E.; Adeli, Khosrow; Howard, Andrew; Sochett, Etienne; Birken, Catherine S.; Parkin, Patricia C.; Maguire, Jonathon L.; Abdullah, Kawsari; Anderson, Laura N.; Birken, Catherine S.; Borkhoff, Cornelia M.; Carsley, Sarah; Chen, Yang; Katz-Lavigne, Mikael; Kavikondala, Kanthi; Kowal, Christine; Maguire, Jonathon L.; Mason, Dalah; Omand, Jessica; Parkin, Patricia C.; Persaud, Navindra; van den Heuvel, Meta; Baker, Jillian; Barozzino, Tony; Bonifacio, Joey; Campbell, Douglas; Cheema, Sohail; Chisamore, Brian; Danayan, Karoon; Das, Paul; Derocher, Mary Beth; Do, Anh; Dorey, Michael; Freeman, Sloane; Fung, Keewai; Guiang, Charlie; Handford, Curtis; Hatch, Hailey; Jacobson, Sheila; Kiran, Tara; Knowles, Holly; Kwok, Bruce; Lakhoo, Sheila; Lam-Antoniades, Margarita; Lau, Eddy; Leung, Fok-Han; Loo, Jennifer; Mahmoud, Sarah; Moodie, Rosemary; Morinis, Julia; Naymark, Sharon; Neelands, Patricia; Owen, James; Peer, Michael; Perlmutar, Marty; Persaud, Navindra; Pinto, Andrew; Porepa, Michelle; Ramji, Nasreen; Ramji, Noor; Rosenthal, Alana; Saunderson, Janet; Saxena, Rahul; Sgro, Michael; Shepherd, Susan; Smiltnieks, Barbara; Taylor, Carolyn; Weisdors, Thea; Wijayasinghe, Sheila; Wong, Peter; Ying, Ethel; Young, Elizabeth

2017-01-01

Abstract The objective of this study was to evaluate the association of vitamin D intake and serum levels with fracture risk in children under 6 years of age. A case-control study was conducted in Toronto, Ontario, Canada. Cases were recruited from the fracture clinic at the Hospital for Sick Children, and matched controls were obtained from the TARGet Kids! primary-care research network. Controls were matched to cases on age, sex, height, and season. Fracture risk was estimated from conditional logistic regression, with adjustment for skin type, fracture history, waist circumference, outdoor free play, neighborhood income, soda consumption, and child's birth weight. A total of 206 cases were recruited during May 2009–April 2013 and matched to 343 controls. Serum 25-hydroxyvitamin D concentration (per 10-nmol/L increment: adjusted odds ratio (aOR) = 0.95, 95% confidence interval (CI): 0.88, 1.03) and intake of cow's milk (2 cups/day vs. 2 cups/day: aOR = 1.39 (95% CI: 0.85, 2.23)) were not significantly associated with reduced odds of fracture. A statistically significant association was observed between child use of vitamin D supplements and decreased odds of fracture (yes vs. no: aOR = 0.42, 95% CI: 0.25, 0.69). Vitamin D supplementation, but not serum 25-hydroxyvitamin D level or milk intake, was associated with reduced fracture risk among these healthy young children. PMID:28459987

Investigation on the use digital controls instead of PID analog controls in the level control of steam generators of nuclear power PWR

International Nuclear Information System (INIS)

Alvarenga, Marco Antonio Bayout

2012-01-01

The aim of this study is to identify current alternatives for the implementation of digital controllers in the level control of steam generators of nuclear power PWR (Pressurized Water Reaetor). It is intended to identify the types of digital controls that are available from the theoretical and conceptual viewpoints for this purpose. We investigate the advantages and disadvantages of each controller model. From this assessment are pointed the most suitable models in hierarchical scale. This evaluation also serves to suggest possible types of control installation as a whole, where the level control of the steam generators becomes just one of many controls that are part of the plant. In this case, the use of digital controls allows the non-linear and multivariable treatment which is characteristic of complex systems, such as the nuclear power generation. The treatment of nonlinearities and multivariable aspects allows a more detailed study of the stability of these plants when they are subject to transients or several accidents, such as the case of losing external power of transients. In the specific case of steam generators, the instabilities result from the emergence of the shrink and swell phenomenas, depending on the load variations of thermonuclear plant. The application of several types and digital controllers, considering these inherent characteristics of the level control of steam generators, allows to infer which types of controllers are more appropriate to treat instabilities of this type and to make conjectures in its use for the cases of more complex instabilities, considering the integration of all nucleus-plant controls.