Use of a non-probabilistic online panel as a control group for case-control studies to investigate food and waterborne outbreaks in Lower Saxony, Germany

To perform a meta-analysis of case-control studies that addressed the association between oral contraceptive pills (OC) use and breast cancer (BrCa), PubMED (MEDLINE), Embase, and the Cochrane Library were searched to identify case-control studies of OC and BrCa published between 2009 and 2020. We used the DerSimonian–Laird method to compute pooled odds ratios (ORs) and confidence intervals (CIs), and the Mantel–Haenszel test to assess the association between OC use and cancer. Forty-two studies were identified that met the inclusion criteria and we included a total of 110,580 women (30,778 into the BrCa group and 79,802 into the control group, of which 15,722 and 38,334 were using OC, respectively). The conducted meta-analysis showed that the use of OC was associated with a significantly increased risk of BrCa in general, OR = 1.15, 95% CI: 1.01 to 1.31, p = 0.0358. Regarding other risk factors for BrCa, we found that increased risk was associated significantly with early menarche, nulliparous, non-breastfeeding, older age at first parity, postmenopause, obesity, smoking, and family history of BrCa. Despite our conclusion that birth control pills increase the cancer risk being supported by extensive previous studies and meta-analyzes, further confirmation is required.

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The ‘well control’ artefact in case/control studies of specific psychiatric disorders

Psychological Medicine ◽

10.1017/s0033291700024338 ◽

1989 ◽

Vol 19 (3) ◽

pp. 737-742 ◽

Cited By ~ 23

Author(s):

Sharon Schwartz ◽

Bruce G. Link

Keyword(s):

Risk Factor ◽

Psychiatric Disorders ◽

Group Selection ◽

Case Control ◽

Control Group ◽

Case Control Studies ◽

Suggested Approach ◽

Well Control ◽

Risk Factor Assessment ◽

Intuitive Appeal

SynopsisAn appropriate choice of controls in case/control studies of specific psychiatric disorders is crucial for valid risk-factor assessment. One suggested approach to control-group selection, the use of a well control group, is the focus of this paper. While using well controls has intuitive appeal, this paper shows that such a procedure can lead to ambiguous and biased results.

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Study designs which can demonstrate and test causation

10.1093/med/9780199682898.003.0003 ◽

2017 ◽

Author(s):

Mark Elwood

Keyword(s):

Cohort Studies ◽

Case Control ◽

Control Group ◽

Case Control Studies ◽

Retrospective Case ◽

Community Based ◽

Cross Sectional ◽

Healthcare Interventions ◽

Intervention Trials ◽

Study Designs

This chapter presents study designs which can test and show causation. Cohort and intervention studies compare people exposed to an agent or intervention with those unexposed or less exposed. Case-control studies compare people affected by a disease or outcome with a control group of unaffected people or representing a total population. Surveys select a sample of people, not chosen by exposure or outcome. Cohort studies may be prospective or retrospective; case-control studies are retrospective; surveys are cross-sectional in time, but retrospective or prospective aspects can be added. In part two, strengths, weaknesses and applications of these designs are shown. Intervention trials, ideally randomised, are the prime method of assessing healthcare interventions; special types include crossover trials and community-based trials. Non-randomised trials are noted. The strengths and weaknesses of cohort studies, case-control studies, and surveys are shown.

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Impact of Severity of Illness Bias and Control Group Misclassification Bias in Case-Control Studies of Antimicrobial-Resistant Organisms

Infection Control and Hospital Epidemiology ◽

10.1086/502549 ◽

2005 ◽

Vol 26 (4) ◽

pp. 342-345 ◽

Cited By ~ 35

Author(s):

Anthony D. Harris ◽

Yehuda Carmeli ◽

Matthew H. Samore ◽

Keith S. Kaye ◽

Eli Perencevich

Keyword(s):

Severity Of Illness ◽

Case Control ◽

Severe Illness ◽

Control Group ◽

Case Control Studies ◽

Clinical Culture ◽

Methodologic Problem ◽

Group 2 ◽

And Control ◽

Group 1

AbstractBackground:Case-control studies often analyze risk factors for antibiotic resistance. Recently published articles have illustrated that randomly selected control-patients may be preferable to those with the susceptible phenotype of the organism. A possible methodologic problem with randomly selected control-patients is potential bias due to control group misclassification. This occurs if some control-patients did not have clinical cultures performed and thus might have been unidentified case-patients. If this bias exists, these studies might be expected to report lower odds ratios (ORs) because control-patients would be more like case-patients.Objective:To analyze potential biases that might arise due to control group misclassification and potentially larger selection biases that may be introduced if control-patients are required to have at least one clinical culture.Patients:One hundred twenty case-patients, 770 control-patients in group 1, and 510 control-patients in group 2.Methods:Two case-control studies. Case-patients had clinical cultures positive for imipenem-resistant Pseudomonas aeruginosa. The first group of control-patients were random. The second group of control-patients were identical to those in group 1 except being required to have at least one clinical culture.Results:Univariate analyses showed higher ORs for case-patients versus control-patients in group 1 (imipenem [OR, 12.5], piperacillin-tazobactam [OR, 3.7], and vancomycin [OR, 4.7]) as compared with case-patients versus control-patients in group 2 (imipenem [OR, 8.0], piperacillin-tazobactam [OR, 2.5], and vancomycin [OR, 3.0]).Conclusion:Requiring control-patients to have at least one clinical culture introduces a selection bias likely because it eliminates patients with less severe illness.

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Oral hormone pregnancy tests and the risks of congenital malformations: a systematic review and meta-analysis

F1000Research ◽

10.12688/f1000research.16758.2 ◽

2019 ◽

Vol 7 ◽

pp. 1725 ◽

Cited By ~ 1

Author(s):

Carl Heneghan ◽

Jeffrey K. Aronson ◽

Elizabeth Spencer ◽

Bennett Holman ◽

Kamal R. Mahtani ◽

...

Keyword(s):

Systematic Review ◽

Cohort Studies ◽

Congenital Malformations ◽

Meta Analysis ◽

Case Control ◽

Control Group ◽

Case Control Studies ◽

Renal Anomalies ◽

Congenital Heart Malformations ◽

Increased Risk

Background: Oral hormone pregnancy tests (HPTs), such as Primodos, containing ethinylestradiol and high doses of norethisterone, were given to over a million women from 1958 to 1978, when Primodos was withdrawn from the market because of concerns about possible teratogenicity. We aimed to study the association between maternal exposure to oral HPTs and congenital malformations. Methods: We have performed a systematic review and meta-analysis of case-control and cohort studies that included data from pregnant women and were exposed to oral HPTs within the estimated first three months of pregnancy, if compared with a relevant control group. We used random-effects meta-analysis and assessed the quality of each study using the Newcastle–Ottawa Scale for non-randomized studies. Results: We found 16 case control studies and 10 prospective cohort studies, together including 71 330 women, of whom 4,209 were exposed to HPTs. Exposure to oral HPTs was associated with a 40% increased risk of all congenital malformations: pooled odds ratio (OR) = 1.40 (95% CI 1.18 to 1.66; P<0.0001; I2 = 0%). Exposure to HPTs was associated with an increased risk of congenital heart malformations: pooled OR = 1.89 (95% CI 1.32 to 2.72; P = 0.0006; I2=0%); nervous system malformations OR = 2.98 (95% CI 1.32 to 6.76; P = 0.0109 I2 = 78%); gastrointestinal malformations, OR = 4.50 (95% CI 0.63 to 32.20; P = 0.13; I2 = 54%); musculoskeletal malformations, OR = 2.24 (95% CI 1.23 to 4.08; P= 0.009; I2 = 0%); the VACTERL syndrome (Vertebral defects, Anal atresia, Cardiovascular anomalies, Tracheoesophageal fistula, Esophageal atresia, Renal anomalies, and Limb defects), OR = 7.47 (95% CI 2.92 to 19.07; P < 0.0001; I2 = 0%). Conclusions: This systematic review and meta-analysis shows that use of oral HPTs in pregnancy is associated with increased risks of congenital malformations.

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Malignant Versus Benign Tumors of the Sinonasal Cavity: A Case-Control Study on Occupational Etiology

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph15122887 ◽

2018 ◽

Vol 15 (12) ◽

pp. 2887 ◽

Cited By ~ 1

Author(s):

Enzo Emanuelli ◽

Vera Comiati ◽

Diego Cazzador ◽

Gloria Schiavo ◽

Enrico Alexandre ◽

...

Keyword(s):

Logistic Regression ◽

Clinical Setting ◽

Textile Industry ◽

Malignant Tumors ◽

Case Control ◽

Benign Tumors ◽

Control Group ◽

Case Control Studies ◽

Occupational Risk Factors ◽

Increased Risk

Case-control studies on malignant sinonasal tumors and occupational risk factors are generally weakened by non-occupational confounders and the selection of suitable controls. This study aimed to confirm the association between sinonasal malignant tumors and patients’ occupations with consideration for sinonasal inverted papillomas (SNIPs) as a control group. Thirty-two patients affected by adenocarcinoma (ADC) and 21 non-adenocarcinoma epithelial tumors (NAETs) were compared to 65 patients diagnosed with SNIPs. All patients were recruited in the same clinical setting between 2004 and 2016. A questionnaire was used to collect information on non-occupational factors (age, sex, smoking, allergies, and chronic sinusitis) and occupations (wood- and leather-related occupations, textile industry, metal working). Odds ratios (OR) with 95% confidence intervals (CI) associated with selected occupations were obtained by a multinomial and exact logistic regression. Between the three groups of patients, SNIP patients were significantly younger than ADC patients (p = 0.026). The risk of NAET increased in woodworkers (OR = 9.42; CI = 1.94–45.6) and metal workers (OR = 5.65; CI = 1.12–28.6). The risk of ADC increased in wood (OR = 86.3; CI = 15.2–488) and leather workers (OR = 119.4; CI = 11.3–1258). On the exact logistic regression, the OR associated to the textile industry was 9.32 (95%CI = 1.10–Inf) for ADC, and 7.21 (95%CI = 0.55–Inf) for NAET. Comparing sinonasal malignant tumors with controls recruited from the same clinical setting allowed demonstrating an increased risk associated with multiple occupations. Well-matched samples of cases and controls reduced the confounding bias and increased the strength of the association.

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CYP17MspA1 Polymorphism and Age at Menarche: A Meta-Analysis

Disease Markers ◽

10.1155/2008/403982 ◽

2008 ◽

Vol 25 (2) ◽

pp. 87-95 ◽

Cited By ~ 3

Author(s):

Yu-Fang Pei ◽

Lei Zhang ◽

Hong-Wen Deng ◽

Volodymyr Dvornyk

Keyword(s):

Meta Analysis ◽

Population Sample ◽

Control Sample ◽

Case Control ◽

Control Group ◽

Age At Menarche ◽

Wild Type ◽

Case Control Studies ◽

Significant Independent Risk Factor ◽

Standardized Mean Difference

Objective: Literature data on the effects ofCYP17 MspA1 polymorphism on age at menarche (AAM) are inconsistent. To reexamine this controversy, we performed a meta-analysis.Study design: In total 16 studies containing more than 11000 individuals of various ethnicities were selected for the analyses. For 11 case-control studies, odds ratio (OR) was employed to evaluate the risk of late AAM for each study, using homozygote at the wild-type allele as a control group. For the 5 studies with continuous outcomes, the effect size was estimated using the Hedges’ adjusted g, which is calculated based on the standardized mean difference between groups of subjects with early and late AAM.Results: We did not find evidence for association of the MspA1 polymorphism with AAM in the combined case-control sample with mixed ethnic background (OR = 1.03, 95% CI: 0.90–1.18,P= 0.66), in the monoethnic case-control sample of Caucasian females (OR = 1.09, 95% CI: 0.99–1.20,P= 0.08) and in the combined sample with continuous traits (Hedges’ g = 0.33 and −0.041, 95% CI: −0.14–0.80 and −0.18–0.10,Pvalues 0.17 and 0.56 for the pooled population sample and monoethnic sample of Caucasian females, respectively).Conclusion: Our study showed thatCYP17 MspA1 polymorphism was not a significant independent risk factor of AAM. Further studies are needed to clarify the effects of the interaction between this gene and other genetic and/or environment factors on AAM.

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Analyzing the Relationship between Cohort and Case-Control Study Results Based on Model for Multiple Pathogenic Factors

Computational and Mathematical Methods in Medicine ◽

10.1155/2019/7507043 ◽

2019 ◽

Vol 2019 ◽

pp. 1-5

Author(s):

Hui Liu

Keyword(s):

Cohort Study ◽

Cohort Studies ◽

Case Control Study ◽

Case Control ◽

Control Group ◽

Case Control Studies ◽

Definite Relationship ◽

Study Results ◽

The Relationship ◽

Control Study

Objective. Although the relative risk from a prospective cohort study is numerically approximate to the odds ratio from a case-control study for a low-probability event, a definite relationship between case-control and cohort studies cannot be confirmed. In this study, we established a different model to determine the relationship between case-control and cohort studies. Methods. Two analysis models (the cross-sectional model and multiple pathogenic factor model) were established. Incidences in both the exposure group and the nonexposure group in a cohort study were compared with the frequency of the observed factor in each group (diseased and nondiseased) in a case-control study. Results. The relationship between the results of a case-control study and a cohort study is as follows: Pe=Pd∗m/Pc∗1−m+Pd∗m; Pn=m∗1−Pd/1−Pc∗1−m−Pd∗m, where Pe and Pn represent the incidence in the exposed group and nonexposed group, respectively, from the cohort study, while Pd and Pc represent the observed frequencies in the disease group and the control group, respectively, for the case-control study; finally, m represents the incidence in the total population. Conclusions. There is a definite relationship between the results of case-control and cohort studies assessing the same exposure. The outcomes of case-control studies can be translated into cohort study data.

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REM-related obstructive sleep apnea and vertigo: A retrospective case-control study

PLoS ONE ◽

10.1371/journal.pone.0252844 ◽

2021 ◽

Vol 16 (6) ◽

pp. e0252844

Author(s):

Po-Yueh Chen ◽

Tzu-Ying Chen ◽

Pin-Zhir Chao ◽

Wen-Te Liu ◽

Chyi-Huey Bai ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Population Based ◽

Case Control ◽

Control Group ◽

Case Control Studies ◽

Retrospective Case ◽

Eligibility Criteria ◽

Obstructive Sleep ◽

Hospital Patients

Background In recent population-based case-control studies, sleep apnea was significantly associated with a higher incidence (hazard ratio, 1.71) of vertigo and the risk of tinnitus was found to increase 1.36 times in patients with sleep apnea. The possibility that obstructive sleep apnea (OSA) might affect neurotological consequences was not noticed, until studies using polysomnography (PSG) for these patients. Objectives The purpose of this study was to investigate the relationship between vertigo and OSA. Methods The collected data among patients from May 1st, 2018 to October 31th, 2018 at Shuang Ho Hospital. Eligibility criteria included an age older than 20 years, a diagnosis of obstructive sleep apnea. The diagnosis of OSA was defined as an oxygen desaturation index of at least 5, was established with the use of polysomnographic examination at hospital. Patients were excluded from the study if they had head injury, brain tumour, headache history and hearing loss. Patients who had vertigo were labeled as Vertigo group. In the other hand, patients who had no dizziness were labeled as control group. 58 patients were in the Vertigo group, and 113 were in the control group. Results After PSG examination, 58 patients who had vertigo, were diagnosed OSA (29 males, average age = 57.07 years old, BMI = 26.64, RDI = 24.69, ESS = 8.65), and 24 patients of them (41.3%) were REM-related OSA. Meanwhile, in the control group, 113 patients had OSA (92male, average age = 49.66 years old, BMI = 26.06, RDI = 35.19, ESS = 11.43), and 18 patients of them (15.9%) were REM-related OSA (Table 1). Therefore, patient who had vertigo, would have higher proportion of REM OSA (P<0.001). Conclusions The vertigo patients have a higher rate of REM-related OSA, and the acceptance rate to CPAP use is low. Further research is needed to explore novel therapeutic approaches, or combination of currently available non-CPAP therapies, in patients with REM OSA.

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Urea Cycle Metabolites and Atrial Fibrillation or Heart Failure Risk: Two Case-Control Studies in the PREDIMED Trial

Current Developments in Nutrition ◽

10.1093/cdn/nzab033_018 ◽

2021 ◽

Vol 5 (Supplement_2) ◽

pp. 18-18

Author(s):

Leticia Goni ◽

Cristina Razquin ◽

Estefania Toledo ◽

Marta Guasch-Ferre ◽

Clary B. Clish ◽

...

Keyword(s):

Heart Failure ◽

Atrial Fibrillation ◽

Dietary Intervention ◽

Urea Cycle ◽

Conditional Logistic Regression ◽

Virgin Olive Oil ◽

Case Control ◽

Control Group ◽

Ratio Test ◽

Case Control Studies

Abstract Objectives To prospectively analyze the associations between urea cycle metabolites and incident atrial fibrillation (AF) or heart failure (HF), and to evaluate the effect of a Mediterranean diet (MD) intervention on such associations. Methods We designed two nested case-control studies within the PREDIMED trial, a randomized controlled trial aimed to evaluate the effect of two MD interventions, supplemented with either extra virgin olive oil (EVOO) or nuts, on cardiovascular disease (CVD). Fasting blood samples were collected at baseline and urea cycle metabolites (arginine, citrulline, and ornithine) and methylarginines (asymmetric dimethylarginine/symmetric dimethylarginine ratio (ADMA/SDMA ratio)) were determined using liquid chromatography tandem mass spectrometry. We used conditional logistic regression models, adjusted for potential confounders, to analyze the associations between the metabolites and incident AF or HF. Potential interactions between metabolites and intervention (MD groups vs control group) were tested with the likelihood ratio test. Results The study population comprised a total of 1241 participants (509 cases) for AF case-control and 824 participants (326 cases) for HF case-control. Arginine was inversely associated with incident AF (OR per SD 0.83, 95% CI 0.73; 0.94) and HF (OR per SD 0.82, 95% CI 0.69; 0.97). Whereas ADMA/SDMA ratio was positively associated with AF (OR per SD 1.19, 95% CI 1.02; 1.41) but not with HF risk. A statistically significant interaction (P = 0.044) was found between arginine and intervention on HF risk. The lower risk of HF associated with arginine was only observed in participants of the MD groups (EVOO + nuts). Conclusions The results of the present study suggest that urea cycle metabolites, arginine and ADMA/SDMA ratio specifically, could be involved in AF and HF pathophysiology. Moreover, the dietary intervention may modify the association between arginine and HF. Funding Sources National Institutes of Health (NIH), Spanish Government Official Agency for funding biomedical research-Instituto de Salud Carlos III (ISCIII) and CIBEROBN

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