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Sample records for large case-control study

  1. Crash involvement of large trucks by configuration: a case-control study.

    PubMed Central

    Stein, H S; Jones, I S

    1988-01-01

    For a two-year period, large truck crashes on the interstate system in Washington State were investigated using a case-control method. For each large truck involved in a crash, three trucks were randomly selected for inspection from the traffic stream at the same time and place as the crash but one week later. The effects of truck and driver characteristics on crashes were assessed by comparing their relative frequency among the crash-involved and comparison sample trucks. Double trailer trucks were consistently overinvolved in crashes by a factor of two to three in both single and multiple vehicle crashes. Single unit trucks pulling trailers also were overinvolved. Doubles also had a higher frequency of jackknifing compared to tractor-trailers. The substantial overinvolvement of doubles in crashes was found regardless of driver age, hours of driving, cargo weight, or type of fleet. Younger drivers, long hours of driving, and operating empty trucks were also associated with higher crash involvement. PMID:3354729

  2. Nasopharyngeal Case-Control Study

    Cancer.gov

    A case-control study conducted in Taiwan between 1991-1994 among approximately 1,000 individuals to examine the role of viral, environmental, and genetic factors associated with the development of nasopharyngeal carcinoma

  3. Lifestyle, family history, and risk of idiopathic Parkinson disease: a large Danish case-control study.

    PubMed

    Kenborg, Line; Lassen, Christina F; Ritz, Beate; Andersen, Klaus K; Christensen, Jane; Schernhammer, Eva S; Hansen, Johnni; Wermuth, Lene; Rod, Naja H; Olsen, Jørgen H

    2015-05-15

    The relationship between Parkinson disease (PD) and smoking has been examined in several studies, but little is known about smoking in conjunction with other behaviors and a family history of PD. Using unconditional logistic regression analysis, we studied individual and joint associations of these factors with idiopathic PD among 1,808 Danish patients who were diagnosed in 1996-2009 and matched to 1,876 randomly selected population controls. Although there was a downward trend in duration of smoking, this was not observed for daily tobacco consumption. A moderate intake of caffeine (3.1-5 cups/day) was associated with a lower odds ratio for PD (0.45, 95% confidence interval: 0.34, 0.62), as was a moderate intake of alcohol (3.1-7 units/week) (odds ratio = 0.60, 95% confidence interval: 0.58, 0.84); a higher daily intake did not reduce the odds further. When these behaviors were studied in combination with smoking, the odds ratios were lower than those for each one alone. Compared with never smokers with no family history of PD, never smokers who did have a family history had an odds ratio of 2.81 (95% confidence interval: 1.91, 4.13); for smokers with a family history, the odds ratio was 1.60 (95% confidence interval: 1.15, 2.23). In conclusion, duration of smoking seems to be more important than intensity in the relationship between smoking and idiopathic PD. The finding of lower risk estimates for smoking in combination with caffeine or alcohol requires further confirmation.

  4. Management of dental extraction in patients undergoing anticoagulant treatment. Results from a large, multicentre, prospective, case-control study.

    PubMed

    Bacci, Christian; Maglione, Michele; Favero, Lorenzo; Perini, Alessandro; Di Lenarda, Roberto; Berengo, Mario; Zanon, Ezio

    2010-11-01

    Following favourable results from a previous study, a large, multicentre, prospective, case-control study was performed to further assess the incidence of bleeding complications after dental extraction in patients taking oral anticoagulant therapy (OAT). Four hundred fifty-one patients being treated with warfarin who required dental extraction were compared with a control group of 449 non-anticoagulated subjects undergoing the same procedure. In the warfarin-treated group, the oral anticoagulant regimen was maintained unchanged, such that the patients had an International Normalised Ratio ranging between 1.8 and 4, and local haemostatic measures (i.e. fibrin sponges, silk sutures and gauzes saturated with tranexamic acid) were adopted. All the procedures were performed in an outpatient setting. Seven bleeding complications occurred in the OAT group and four in the control group; the difference in the number of bleeding events between the two groups was not statistically significant (OR=1.754; 95% CI 0.510 - 6.034; p=0.3727). No post-operative late bleeds requiring hospitalisation and/or blood transfusions were recorded, and the adjunctive local haemostatic measures were adequate to stop the bleeding. The results of our protocol applied in this large, multicenter study show that dental extractions can be performed easily and safely in anticoagulated outpatients without any modification of the ongoing anticoagulant therapy, thus minimising costs and reducing discomfort for patients.

  5. Polymorphic variants in PTGS2 and prostate cancer risk: results from two large nested case-control studies.

    PubMed

    Danforth, Kim N; Hayes, Richard B; Rodriguez, Carmen; Yu, Kai; Sakoda, Lori C; Huang, Wen-Yi; Chen, Bingshu E; Chen, Jinbo; Andriole, Gerald L; Calle, Eugenia E; Jacobs, Eric J; Chu, Lisa W; Figueroa, Jonine D; Yeager, Meredith; Platz, Elizabeth A; Michaud, Dominique S; Chanock, Stephen J; Thun, Michael J; Hsing, Ann W

    2008-03-01

    Chronic inflammation has been hypothesized to increase prostate cancer risk. Prostaglandin-endoperoxide synthase 2 (PTGS2) encodes the proinflammatory cyclooxygenase 2 enzyme believed to be the rate-limiting step in the synthesis of prostaglandins, important mediators of inflammation. We investigated associations between PTGS2 polymorphisms and prostate cancer risk among 2321 prostate cancer cases and 2560 controls in two large case-control studies nested within the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial and the Cancer Prevention Study II Nutrition Cohort. Five single nucleotide polymorphisms (SNPs) (rs5277, rs20432, rs4648276, rs5275 and rs689470) were examined in SNP and haplotype analyses (five SNPs in PLCO and four SNPs in the Nutrition Cohort). In PLCO, the Ex10 +837 T>C marker (rs5275) was initially associated with prostate cancer risk (P-trend = 0.02) but became non-significant after adjustment for multiple comparisons (P = 0.08); this SNP showed no association with prostate cancer risk in the Nutrition Cohort (P-trend = 0.54) or in an analysis pooling the two cohorts (P-trend = 0.20). No other SNP was associated with prostate cancer risk in PLCO or the Nutrition Cohort individually or combined. Haplotype analyses suggested an association between PTGS2 variants in PLCO alone (global P = 0.007), but not in the Nutrition Cohort (global P = 0.78) or pooled analysis (global P = 0.18). In conclusion, despite the potential importance of inflammation in prostate carcinogenesis, results from our large study of five PTGS2 SNPs does not support a strong association between PTGS2 variants and prostate cancer risk in non-Hispanic white men.

  6. Case-control studies: basic concepts.

    PubMed

    Vandenbroucke, Jan P; Pearce, Neil

    2012-10-01

    The purpose of this article is to present in elementary mathematical and statistical terms a simple way to quickly and effectively teach and understand case-control studies, as they are commonly done in dynamic populations-without using the rare disease assumption. Our focus is on case-control studies of disease incidence ('incident case-control studies'); we will not consider the situation of case-control studies of prevalent disease, which are published much less frequently.

  7. Joint and independent effects of alcohol drinking and tobacco smoking on oral cancer: a large case-control study.

    PubMed

    Ferreira Antunes, José Leopoldo; Toporcov, Tatiana Natasha; Biazevic, Maria Gabriela Haye; Boing, Antonio Fernando; Scully, Crispian; Petti, Stefano

    2013-01-01

    Alcohol drinking and tobacco smoking are assumed to have significant independent and joint effects on oral cancer (OC) development. This assumption is based on consistent reports from observational studies, which, however, overestimated the independent effects of smoking and drinking, because they did not account for the interaction effect in multivariable analyses. This case-control study sought to investigate the independent and the joint effects of smoking and drinking on OC in a homogeneous sample of adults. Case patients (N = 1,144) were affected by invasive oral/oropharyngeal squamous cell carcinoma confirmed histologically, diagnosed between 1998 and 2008 in four hospitals of São Paulo (Brazil). Control patients (N = 1,661) were not affected by drinking-, smoking-associated diseases, cancers, upper aero-digestive tract diseases. Cumulative tobacco and alcohol consumptions were assessed anamnestically. Patients were categorized into never/ever users and never/level-1/level-2 users, according to the median consumption level in controls. The effects of smoking and drinking on OC adjusted for age, gender, schooling level were assessed using logistic regression analysis; Model-1 did not account for the smoking-drinking interaction; Model-2 accounted for this interaction and included the resultant interaction terms. The models were compared using the likelihood ratio test. According to Model-1, the adjusted odds ratios (ORs) for smoking, drinking, smoking-drinking were 3.50 (95% confidence interval -95CI, 2.76-4.44), 3.60 (95CI, 2.86-4.53), 12.60 (95CI, 7.89-20.13), respectively. According to Model-2 these figures were 1.41 (95CI, 1.02-1.96), 0.78 (95CI, 0.48-1.27), 8.16 (95CI, 2.09-31.78). Analogous results were obtained using three levels of exposure to smoking and drinking. Model-2 showed statistically significant better goodness-of-fit statistics than Model-1. Drinking was not independently associated with OC, while the independent effect of smoking

  8. Case-Control Study of Writer's Cramp

    ERIC Educational Resources Information Center

    Roze, E.; Soumare, A.; Pironneau, I.; Sangla, S.; de Cock, V. Cochen; Teixeira, A.; Astorquiza, A.; Bonnet, C.; Bleton, J. P.; Vidailhet, M.; Elbaz, A.

    2009-01-01

    Task-specific focal dystonias are thought to be due to a combination of individual vulnerability and environmental factors. There are no case-control studies of risk factors for writer's cramp. We undertook a case-control study of 104 consecutive patients and matched controls to identify risk factors for the condition. We collected detailed data…

  9. Are nested case-control studies biased?

    PubMed Central

    Langholz, Bryan; Richardson, David

    2014-01-01

    It has been recently asserted that the nested case-control study design, in which case-control sets are sampled from cohort risk sets, can introduce bias (“study design bias”) when there are lagged exposures. The bases for this claim include a theoretic and an “empirical evaluation” argument. Both of these arguments are examined and found to be incorrect. Appropriate methods to explore the performance of nested case-control study designs, analysis methods, and compute power and sample size from an existing cohort are described. This empirical evaluation approach relies on simulating case-control outcomes from risk sets in the cohort from which the case-control study is to be performed. Because it is based on the underlying cohort structure, the empirical evaluation can provide an assessment that is tailored to the specific characteristics of the study under consideration. The methods are illustrated using samples from the Colorado Plateau uranium miners cohort. PMID:19289963

  10. Plasma folate, methylenetetrahydrofolate reductase (MTHFR), and colorectal cancer risk in three large nested case-control studies.

    PubMed

    Lee, Jung Eun; Wei, Esther K; Fuchs, Charles S; Hunter, David J; Lee, I-Min; Selhub, Jacob; Stampfer, Meir J; Willett, Walter C; Ma, Jing; Giovannucci, Edward

    2012-04-01

    Few prospective studies have examined the associations between blood levels of folate, in conjunction with methylenetetrahydrofolate reductase (MTHFR) polymorphisms, and colorectal cancer. We evaluated the associations between plasma folate, MTHFR C677T, and A1298C, and colorectal cancer in three large prospective studies: the Nurses' Health Study, the Health Professionals Follow-up Study, and the Physicians' Health Study. A total of 602 incident cases were identified and individually matched to controls who provided blood specimens. We used conditional logistic regression to calculate the relative risk (RR) and 95% confidence interval (95% CI) and then pooled the estimates using a random effects model. We found a lower risk of colorectal cancer among participants with low plasma folate levels: compared with the lowest quartile, RRs (95% CIs) for each successively higher quartile of plasma folate levels were 1.55 (1.14-2.11), 1.37 (1.00-1.88), and 1.47 (1.07-2.01; P for trend = 0.10). For the MTHFR polymorphisms, RRs (95% CIs) were 0.62 (0.44-0.90) for 677TT versus CC/CT and 0.68 (0.31-1.51) for 1298CC versus AC/AA, and these lower-risk genotypes were associated with lower circulating plasma folate levels. When we partitioned the variation in plasma folate levels, variation due to folate intake was not positively associated with colorectal cancer risk. We found that low plasma folate levels were associated with lower risk of colorectal cancer. The reasons underlying a lower risk of colorectal cancer with low plasma folate levels require elucidation because plasma folate levels can reflect dietary intake, genetic influences, and other factors.

  11. Plasma folate, methylenetetrahydrofolate reductase (MTHFR), and colorectal cancer risk in three large nested case-control studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Few prospective studies have examined the associations between blood levels of folate, in conjunction with methylenetetrahydrofolate reductase (MTHFR) polymorphisms, and colorectal cancer. We evaluated the associations between plasma folate, MTHFR C677T, and A1298C, and colorectal cancer in three la...

  12. Association between XRCC3 Thr241Met polymorphism and nasopharyngeal carcinoma risk: evidence from a large-scale case-control study and a meta-analysis.

    PubMed

    Cui, Qian; Zuo, Xiao-Yu; Lian, Yi-Fan; Feng, Qi-Sheng; Xia, Yun-Fei; He, Cai-Yun; Chen, Li-Zhen; Jia, Wei-Hua; Mai, Hai-Qiang; Zeng, Yi-Xin; Bei, Jin-Xin

    2016-11-01

    The X-ray repair cross-complementing group 3 (XRCC3) Thr241Met polymorphism (rs861539, C > T) has drawn wide attentions as its association with cancer risk and its involvement in DNA repair. Several studies have attempted to link rs861539 to nasopharyngeal cancer (NPC) risk; however, the sample sizes of these studies are small and the results are controversial. To investigate the relationship of rs861539 and NPC susceptibility, we conducted a large-scale case-control study involving 4001 NPC cases and 2967 controls of southern Chinese. Logistic regression analysis revealed significant association for rs861539 and NPC risk under the recessive model (TT vs. CT + CC) with adjustment of age and gender (odds ratio, OR = 2.72; 95 % CI 1.10-6.72; P = 0.03). Further, meta-analysis involving 4457 NPC cases and 4132 controls from four studies showed consistent association of TT carriers and NPC risk (OR = 3.12; 95 % CI 1.58-6.13; P = 0.001). Taken together, our findings based on large-scale sample size suggested rs861539 at XRCC3 to be associated with NPC risk through recessive model.

  13. The glu298asp polymorphism in the nitric oxide synthase 3 gene is associated with the risk of ischemic stroke in two large independent case-control studies.

    PubMed

    Berger, Klaus; Stögbauer, Florian; Stoll, Monika; Wellmann, Juergen; Huge, Andreas; Cheng, Suzanne; Kessler, Christof; John, Ulrich; Assmann, Gerd; Ringelstein, E Bernd; Funke, Harald

    2007-04-01

    The search for genes involved in the pathogenesis of stroke has been highlighted as a field of needs. We followed the concept, that stroke represents a complex genetic disorder, and analyzed the contribution of 106 informative single nucleotide polymorphisms (SNPs) from 63 candidate genes for cardiovascular diseases for the risk of stroke. We conducted two independent case-control studies in two different German regions and recruited a total of 1,901 hospitalized stroke cases and 1,747 regional population controls. The smaller of both studies was used as the replication study. Multiplex PCR in combination with allele-specific hybridization was used for genotype determination. Descriptive statistics, permutations and multivariable logistic regression were used in the analyses. After permutation testing 5 SNPs, located in the nitric oxide synthase 3, the alpha 2 integrin, the interleukin 13, the selectin P and the chemokine receptor 2 genes, had a significant allele difference between cases and controls in the larger study. For one of these SNPs, the glu298asp polymorphism in the nitric oxide synthase 3 gene, an association with ischemic stroke was replicated in the second study and also in a combined analysis of both studies. This association was independent of age, gender, hypertension, diabetes and hypercholesterolemia in both studies. Using large sample sizes and a replication study approach, we found evidence for a role of a polymorphism in the nitric oxide synthase 3 gene in stroke onset.

  14. A large-scale, hospital-based case-control study of risk factors of breast cancer according to menopausal status.

    PubMed

    Hirose, K; Tajima, K; Hamajima, N; Inoue, M; Takezaki, T; Kuroishi, T; Yoshida, M; Tokudome, S

    1995-02-01

    We conducted a large-scale, hospital-based case-control study to evaluate differences and similarities in the risk factors of female breast cancer according to menopausal status. This study is based on a questionnaire survey on life style routinely obtained from outpatients who first visited the Aichi Cancer Center Hospital between January 1, 1988 and December 31, 1992. Among 36,944 outpatients, 1,186 women with breast cancer detected by histological examination were taken as the case group (607 premenopausal women and 445 postmenopausal women) and 23,163 women confirmed to be free of cancer were selected as the control group. New findings and reconfirmed factors of breast cancer were as follows. 1) The risk of at least one breast cancer history among subjects' first-degree relatives was relatively high among pre- as well as post-menopausal women. 2) A protective effect of physical activity against breast cancer was observed among both pre- and post-menopausal women. 3) Dietary control decreased the risk of premenopausal breast cancer. 4) Current smoking and drinking elevated the risk of breast cancer in premenopausal women. 5) Decreasing trends of breast cancer risk were associated with intake of bean curd, green-yellow vegetables, potato or sweet potato, chicken and ham or sausage in premenopausal women, while in postmenopausal women a risk reduction was associated with a more frequent intake of boiled, broiled and/or raw fish (sashimi). Further study will be needed to clarify the age group- and/or birth cohort-specific risk factors for breast cancer among the young generation in Japan.

  15. Experience with multiple control groups in a large population-based case-control study on genetic and environmental risk factors.

    PubMed

    Pomp, E R; Van Stralen, K J; Le Cessie, S; Vandenbroucke, J P; Rosendaal, F R; Doggen, C J M

    2010-07-01

    We discuss the analytic and practical considerations in a large case-control study that had two control groups; the first control group consisting of partners of patients and the second obtained by random digit dialling (RDD). As an example of the evaluation of a general lifestyle factor, we present body mass index (BMI). Both control groups had lower BMIs than the patients. The distribution in the partner controls was closer to that of the patients, likely due to similar lifestyles. A statistical approach was used to pool the results of both analyses, wherein partners were analyzed with a matched analysis, while RDDs were analyzed without matching. Even with a matched analysis, the odds ratio with partner controls remained closer to unity than with RDD controls, which is probably due to unmeasured confounders in the comparison with the random controls as well as intermediary factors. However, when studying injuries as a risk factor, the odds ratio remained higher with partner control subjects than with RRD control subjects, even after taking the matching into account. Finally we used factor V Leiden as an example of a genetic risk factor. The frequencies of factor V Leiden were identical in both control groups, indicating that for the analyses of this genetic risk factor the two control groups could be combined in a single unmatched analysis. In conclusion, the effect measures with the two control groups were in the same direction, and of the same order of magnitude. Moreover, it was not always the same control group that produced the higher or lower estimates, and a matched analysis did not remedy the differences. Our experience with the intricacies of dealing with two control groups may be useful to others when thinking about an optimal research design or the best statistical approach.

  16. [Case-control study of moyamoya disease].

    PubMed

    Yamaguchi, T; Matsushima, Y; Takada, Y; Niimi, Y; Umezu, R; Fukuyama, Y; Yamaguchi, M; Inaba, Y

    1989-05-01

    The cause of Moyamoya disease is still unknown. We made a research about the factors closely related to Moyamoya disease through a case-control study. The number of cases studied was 66. Controls were selected from among patients' friends, matched as to sex, age and residential area. Questionnaires were sent to the cases and the respective controls by mail. The questions were about past history, developmental history, school records, habitual factors, dietary habits and pets. The first symptoms and age at onset were also surveyed in the cases. The response rate was 84.8% (56 cases) of the cases and 76.5% (101 cases) out of the 132 controls. There was no significant difference in the prevalence of tonsillitis, conjunctivitis, otitis media, and bronchitis. Odds ratio of fever of unknown origin is 2.793 and X2 is 7.213. Diseases whose odds ratio was over 1 were herpes, appendicitis, bronchitis, asthma, anemia, dental caries, head injury and drug allergy. But all of them were not significantly prevalent. Odds ratios of school records were 4-9 and X2 were 4-17 from elementary to junior high school. Odds ratio of western dishes was 2.709 and X2 was 5.189. There was no significant difference as to pets kept. We could not find overt relationships between Moyamoya disease and diseases of head and neck like tonsillitis.

  17. The Joint Effects of Lifestyle Factors and Comorbidities on the Risk of Colorectal Cancer: A Large Chinese Retrospective Case-Control Study

    PubMed Central

    Hu, Hai; Zhou, Yangyang; Ren, Shujuan; Wu, Jiajin; Zhu, Meiying; Chen, Donghui; Yang, Haiyan; Wang, Liwei

    2015-01-01

    Background Colorectal cancer (CRC) is a major cause of cancer morbidity and mortality. In previous epidemiologic studies, the respective correlation between lifestyle factors and comorbidity and CRC has been extensively studied. However, little is known about their joint effects on CRC. Methods We conducted a retrospective case-control study of 1,144 diagnosed CRC patients and 60,549 community controls. A structured questionnaire was administered to the participants about their socio-demographic factors, anthropometric measures, comorbidity history and lifestyle factors. Logistic regression model was used to calculate the odds ratio (ORs) and 95% confidence intervals (95%CIs) for each factor. According to the results from logistic regression model, we further developed healthy lifestyle index (HLI) and comorbidity history index (CHI) to investigate their independent and joint effects on CRC risk. Results Four lifestyle factors (including physical activities, sleep, red meat and vegetable consumption) and four types of comorbidity (including diabetes, hyperlipidemia, history of inflammatory bowel disease and polyps) were found to be independently associated with the risk of CRC in multivariant logistic regression model. Intriguingly, their combined pattern- HLI and CHI demonstrated significant correlation with CRC risk independently (ORHLI: 3.91, 95%CI: 3.13–4.88; ORCHI: 2.49, 95%CI: 2.11–2.93) and jointly (OR: 10.33, 95%CI: 6.59–16.18). Conclusions There are synergistic effects of lifestyle factors and comorbidity on the risk of colorectal cancer in the Chinese population. PMID:26710070

  18. A case-control study of surgical site infection following operative fixation of fractures of the ankle in a large U.K. trauma unit.

    PubMed

    Korim, M T; Payne, R; Bhatia, M

    2014-05-01

    Most of the literature on surgical site infections following the surgical treatment of fractures of the ankle is based on small series of patients, focusing on diabetics or the elderly. None have described post-operative functional scores in those patients who develop an infection. We performed an age- and gender-matched case-control study to identify patient- and surgery-related risk factors for surgical site infection following open reduction and internal fixation of a fracture of the ankle. Logistic regression analysis was used to identify significant risk factors for infection and to calculate odds ratios (OR). Function was assessed using the Olerud and Molander Ankle Score. The incidence of infection was 4% (29/717) and 1.1% (8/717) were deep infections. The median ankle score was significantly lower in the infection group compared with the control group (60 vs 90, Mann-Whitney test p < 0.0001). Multivariate regression analysis showed that diabetes (OR = 15, p = 0.031), nursing home residence (OR = 12, p = 0.018) and Weber C fractures (OR = 4, p = 0.048) were significant risk factors for infection. A low incidence of infection following open reduction and internal fixation of fractures of the ankle was observed. Both superficial and deep infections result in lower functional scores.

  19. Maté drinking and esophageal squamous cell carcinoma in South America: pooled results from two large multi-center case-control studies

    PubMed Central

    Lubin, Jay H.; De Stefani, Eduardo; Abnet, Christian C.; Acosta, Gisele; Boffetta, Paolo; Victora, Cesar; Graubard, Barry I.; Muñoz, Nubia; Deneo-Pellegrini, Hugo; Franceschi, Silvia; Castellsagué, Xavier; Ronco, Alvaro L; Dawsey, Sanford M.

    2013-01-01

    Background Maté tea is non-alcoholic infusion widely consumed in southern South America, and may increase risk of esophageal squamous cell carcinoma (ESCC) and other cancers due to polycyclic aromatic hydrocarbons and/or thermal injury. Methods We pooled two case-control studies: a 1988–2005 Uruguay study and a 1986–1992 multinational study in Argentina, Brazil, Paraguay and Uruguay, including 1,400 cases and 3,229 controls. We computed odds ratios (OR) and fitted a linear excess odds ratio (EOR) model for cumulative maté consumption in liters/day-year (LPDY). Results The adjusted OR for ESCC with 95% confidence interval (CI) by ever compared with never use of maté was 1.60 (1.2,2.2). ORs increased linearly with LPDY (test of non-linearity, P=0.69). The estimate of slope (EOR/LPDY) was 0.009 (0.005,0.014) and did not vary with daily intake, indicating maté intensity did not influence the strength of association. EOR/LPDY estimates for consumption at warm, hot and very hot beverage temperatures were 0.004 (−0.002,0.013), 0.007 (0.003,0.013) and 0.016 (0.009,0.027), respectively, and differed significantly (P<0.01). EOR/LPDY estimates were increased in younger (<65) individuals and never alcohol drinkers, but these evaluations were post hoc, and were homogeneous by sex. Conclusions ORs for ESCC increased linearly with cumulative maté consumption and were unrelated to intensity, so greater daily consumption for shorter duration or lesser daily consumption for longer duration resulted in comparable ORs. The strength of association increased with higher mate temperatures. Impact Increased understanding of cancer risks with maté consumption enhances the understanding of the public health consequences given its purported health benefits. PMID:24130226

  20. Risk of bleeding and antibiotic use in patients receiving continuous phenprocoumon therapy. A case-control study nested in a large insurance- and population-based German cohort.

    PubMed

    Abbas, Sascha; Ihle, Peter; Harder, Sebastian; Schubert, Ingrid

    2014-05-05

    There is major concern about coumarins interacting with various drug classes and increasing the risk of overanticoagulation. The aim of the study was to assess bleeding risk in patients with concurrent use of antibiotics and phenprocoumon, the most widely prescribed coumarin in many European countries. We conducted a nested-case-control study within a cohort of 513,338 incident and continuous phenprocoumon users ≥ 18 years of age using claims data of the statutory health insurance company AOK, covering 30% of the German population. Bleeding risk associated with current use of antibiotics for systemic use (antibacterials/antimycotics) was calculated using conditional logistic regression in 13,785 cases with a bleeding event and 55,140 risk-set sampling-matched controls. Bleeding risk associated with any antibacterial use in phenprocoumon users was significantly increased [odds ratio (OR) 2.37, 95% confidence interval (CI) 2.20-2.56]. The association was stronger for gastrointestinal than for cerebral bleeding (OR 2.09, 95% CI 1.84-2.38 and OR 1.34, 95% CI 1.03-1.74, respectively) and highest for other/unspecified bleeding (OR 2.92, 95% CI 2.62-3.26). Specific antibiotic classes were strongly associated with bleeding risk, e.g. cotrimoxazole (OR 3.86, 95% CI 3.08-4.84) and fluorquinolones (OR 3.13, 95% CI 2.74-3.59), among those highest for ofloxacin (OR 5.00, 95% CI 3.01-8.32). Combined use of phenprocoumon and antimycotics was not significantly associated with bleeding risk. Risk was not significantly modified by age (pint=0.25) or sex (pint=0.96). The association was stronger the closer the antibiotic exposure was to the bleeding event. Among continuous phenprocoumon users, antibiotics - particularly quinolones and cotrimoxazole - should be prescribed after careful consideration due to an increased bleeding risk. Close monitoring of international normalised ratio levels after prescription is recommended.

  1. Population-based case-control association studies.

    PubMed

    Hancock, Dana B; Scott, William K

    2012-07-01

    This unit provides an overview of the design and analysis of population-based case-control studies of genetic risk factors for complex disease. Considerations specific to genetic studies are emphasized. The unit reviews basic study designs differentiating case-control studies from others, presents different genetic association strategies (candidate gene, genome-wide association, and high-throughput sequencing), introduces basic methods of statistical analysis for case-control data and approaches to combining case-control studies, and discusses measures of association and impact. Admixed populations, controlling for confounding (including population stratification), consideration of multiple loci and environmental risk factors, and complementary analyses of haplotypes, genes, and pathways are briefly discussed. Readers are referred to basic texts on epidemiology for more details on general conduct of case-control studies.

  2. Chronic lymphocytic leukaemia: case control epidemiological study in Yorkshire.

    PubMed Central

    Cartwright, R. A.; Bernard, S. M.; Bird, C. C.; Darwin, C. M.; O'Brien, C.; Richards, I. D.; Roberts, B.; McKinney, P. A.

    1987-01-01

    This is the second report of a large case control study of lymphoma/leukaemia occurring in Yorkshire during 1979-84, and deals with chronic lymphocytic leukaemia presenting either in its haematological (CLL) or more solid lymphomatous (malignant lymphoma-lymphocytic or MLL) forms. In all, 330 cases and 561 controls were interviewed. The results support the concept that CLL/MLL is a condition of multiple aetiologies with evidence for genetic predisposition through an excess of family cases, immune perturbation demonstrated by excessive previous skin diseases and phenylbutazone use, and viral involvement shown by links with infectious diseases and multiple sclerosis. PMID:3304389

  3. Chronic lymphocytic leukaemia: case control epidemiological study in Yorkshire.

    PubMed

    Cartwright, R A; Bernard, S M; Bird, C C; Darwin, C M; O'Brien, C; Richards, I D; Roberts, B; McKinney, P A

    1987-07-01

    This is the second report of a large case control study of lymphoma/leukaemia occurring in Yorkshire during 1979-84, and deals with chronic lymphocytic leukaemia presenting either in its haematological (CLL) or more solid lymphomatous (malignant lymphoma-lymphocytic or MLL) forms. In all, 330 cases and 561 controls were interviewed. The results support the concept that CLL/MLL is a condition of multiple aetiologies with evidence for genetic predisposition through an excess of family cases, immune perturbation demonstrated by excessive previous skin diseases and phenylbutazone use, and viral involvement shown by links with infectious diseases and multiple sclerosis.

  4. The minimal invasive direct anterior approach in combination with large heads in total hip arthroplasty - is dislocation still a major issue? a case control study

    PubMed Central

    2014-01-01

    Background There have been increasing numbers of publications in recent years on minimally invasive surgery (MIS) for total hip arthroplasty (THA), reporting results with the use of different head sizes, tribologic and functional outcomes. This study presents the results and early complication rates after THA using the direct anterior approach (DAA) in combination with head sizes ≥ 36 mm. Methods A total of 113 patients with THA were included in the study. The Harris Hip Score (HHS) was determined, a radiographic evaluation was carried out, and complications were recorded. The minimum follow-up period was 2 years (means 35 ± 7 months). Results The HHS improved from 43.6 (± 12) to 88.2 (± 14; P < 0.01). One early infection occurred, one periprosthetic fracture, and three cases of aseptic stem loosening. No incorrect positioning of the implants was observed, and there were no dislocations. Conclusion THA with the minimally invasive DAA in combination with large heads is associated with good to very good functional results in the majority of cases. The complication rates are not increased. The rate of dislocation mainly as an complication of the first two years can be markedly reduced in particular. PMID:24621189

  5. Temporomandibular disorders. A case-control study

    PubMed Central

    Bagán, Jose V.; Sanchis, Jose M.; Carbonell, Enrique

    2012-01-01

    Objective: To compare the risk factors and clinical manifestations of patients with temporomandibular disorders (TMDs) diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) (axis I) versus an age and gender matched control group. Study Design: A total of 162 patients explored according to the RDC/TMD (mean age 40.6±18.8 years, range 7-90; 11.1% males and 88.9% females) were compared with 119 controls, measuring differences in TMD risk factors (sleep disturbances, stress, psychoactive medication, parafunctions, loss of posterior support, ligament hyperlaxity) and clinical variables (joint sounds, painful muscle and joint palpation, maximum aperture). Results: Myofascial pain (MFP) (single or multiple diagnoses) was the most frequent diagnosis (42%). The most common diagnostic combination was MFP plus arthralgia (16.0%). Statistically significant differences were observed in clenching (OR 2.3; 95%CI: 1.4-3.8) and in maximum active aperture (MAA) on comparing the two groups both globally (TMD vs. controls) (patients 36.7±8.6 mm, controls 43.1±5.8 mm; F=45.41, p = 0.000) and on comparing according to diagnostic categories. MFP explained most of the observed differences in the risk factors: stress perception (OR=1.98;I.C.:1.01-3.89), psychoactive medication (OR=2.21; I.C.:1.12-4.37), parafunctions (OR=2.14;I.C.:1.12-4.11), and ligament laxity (OR=2.6;I.C.:1.01-6.68). Joint sounds were more frequent in patients with MFP (39.7% vs. 24.0%; χ2=4.66; p=0.03), and painful joint palpation was more common in patients with disc displacement with reduction (DDWR)(15.9% vs. 5.0%; χ2 = 5.2; p = 0.02) and osteoarthrosis (20.8% vs. 5.0%; χ2 = 7.0; p = 0.008). Conclusions: There is a high prevalence of signs and symptoms of TMDs in the general population. Significant differences are observed in clenching and MAA between patients and controls considered both globally and for each diagnostic category individually. The analyzed risk

  6. Pooled exposure assessment for matched case-control studies.

    PubMed

    Saha-Chaudhuri, Paramita; Umbach, David M; Weinberg, Clarice R

    2011-09-01

    Exposure assessment using biologic specimens is important for epidemiology but may become impracticable if assays are expensive, specimen volumes are marginally adequate, or analyte levels fall below the limit of detection. Pooled exposure assessment can provide an effective remedy for these problems in unmatched case-control studies. We extend pooled exposure strategies to handle specimens collected in a matched case-control study. We show that if a logistic model applies to individuals, then a logistic model also applies to an analysis using pooled exposures. Consequently, the individual-level odds ratio can be estimated while conserving both cost and specimen. We discuss appropriate pooling strategies for a single exposure, with adjustment for multiple, possibly continuous, covariates (confounders) and assessment of effect modification by a categorical variable. We assess the performance of the approach via simulations and conclude that pooled strategies can markedly improve efficiency for matched as well as unmatched case-control studies.

  7. Improving statistical analysis of matched case-control studies.

    PubMed

    Conway, Aaron; Rolley, John X; Fulbrook, Paul; Page, Karen; Thompson, David R

    2013-06-01

    Matched case-control research designs can be useful because matching can increase power due to reduced variability between subjects. However, inappropriate statistical analysis of matched data could result in a change in the strength of association between the dependent and independent variables or a change in the significance of the findings. We sought to ascertain whether matched case-control studies published in the nursing literature utilized appropriate statistical analyses. Of 41 articles identified that met the inclusion criteria, 31 (76%) used an inappropriate statistical test for comparing data derived from case subjects and their matched controls. In response to this finding, we developed an algorithm to support decision-making regarding statistical tests for matched case-control studies.

  8. Nested case-control studies in cohorts with competing events.

    PubMed

    Wolkewitz, Martin; Cooper, Ben S; Palomar-Martinez, Mercedes; Olaechea-Astigarraga, Pedro; Alvarez-Lerma, Francisco; Schumacher, Martin

    2014-01-01

    In nested case-control studies, incidence density sampling is the time-dependent matching procedure to approximate hazard ratios. The cumulative incidence function can also be estimated if information from the full cohort is used. In the presence of competing events, however, the cumulative incidence function depends on the hazard of the disease of interest and on the competing events hazard. Using hospital-acquired infection as an example (full cohort), we propose a sampling method for nested case-control studies to estimate subdistribution hazard ratios. With further information on the full cohort, the cumulative incidence function for the event of interest can then be estimated as well.

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

    PubMed

    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.

  10. Melanoma and occupation: results of a case-control study.

    PubMed Central

    Fritschi, L; Siemiatycki, J

    1996-01-01

    OBJECTIVES: Associations between occupational exposures and the occurrence of cutaneous melanoma were examined as part of a large population based case-control study of 19 cancer sites. METHODS: Cases were men aged 35 to 70 years old, resident in Montreal, Canada, with a new histologically confirmed cutaneous melanoma (n = 103). There were two control groups, a randomly selected population control group (n = 533), and a cancer control group (n = 533) randomly selected from among subjects with other types of cancer in the large study. Odds ratios for the occurrence of melanoma were calculated for each exposure circumstance for which there were more than four exposed cases (85 substances, 13 occupations, and 20 industries) adjusting for age, ethnicity, and number of years of schooling. RESULTS: Significantly increased risk of melanoma was found for exposure to four substances (fabric dust, plastic dust, trichloroethylene, and a group containing paints used on surfaces other than metal and varnishes used on surfaces other than wood), three occupations (warehouse clerks, salesmen, and miners and quarrymen), and two industries (clothing and non-metallic mineral products). CONCLUSIONS: Most of the occupational circumstances examined were not associated with melanoma, nor is there any strong evidence from previous research that any of those are risk factors. For the few occupational circumstances which were associated in our data with melanoma, the statistical evidence was weak, and there is little or no supporting evidence in the scientific literature. On the whole, there is no persuasive evidence of occupational risk factors for melanoma, but the studies have been too small or have involved too much misclassification of exposure for this conclusion to be definitive. PMID:8704857

  11. Methodology Series Module 2: Case-control Studies.

    PubMed

    Setia, Maninder Singh

    2016-01-01

    Case-Control study design is a type of observational study. In this design, participants are selected for the study based on their outcome status. Thus, some participants have the outcome of interest (referred to as cases), whereas others do not have the outcome of interest (referred to as controls). The investigator then assesses the exposure in both these groups. The investigator should define the cases as specifically as possible. Sometimes, definition of a disease may be based on multiple criteria; thus, all these points should be explicitly stated in case definition. An important aspect of selecting a control is that they should be from the same 'study base' as that of the cases. We can select controls from a variety of groups. Some of them are: General population; relatives or friends; and hospital patients. Matching is often used in case-control control studies to ensure that the cases and controls are similar in certain characteristics, and it is a useful technique to increase the efficiency of the study. Case-Control studies can usually be conducted relatively faster and are inexpensive - particularly when compared with cohort studies (prospective). It is useful to study rare outcomes and outcomes with long latent periods. This design is not very useful to study rare exposures. Furthermore, they may also be prone to certain biases - selection bias and recall bias.

  12. Informed conditioning on clinical covariates increases power in case-control association studies.

    PubMed

    Zaitlen, Noah; Lindström, Sara; Pasaniuc, Bogdan; Cornelis, Marilyn; Genovese, Giulio; Pollack, Samuela; Barton, Anne; Bickeböller, Heike; Bowden, Donald W; Eyre, Steve; Freedman, Barry I; Friedman, David J; Field, John K; Groop, Leif; Haugen, Aage; Heinrich, Joachim; Henderson, Brian E; Hicks, Pamela J; Hocking, Lynne J; Kolonel, Laurence N; Landi, Maria Teresa; Langefeld, Carl D; Le Marchand, Loic; Meister, Michael; Morgan, Ann W; Raji, Olaide Y; Risch, Angela; Rosenberger, Albert; Scherf, David; Steer, Sophia; Walshaw, Martin; Waters, Kevin M; Wilson, Anthony G; Wordsworth, Paul; Zienolddiny, Shanbeh; Tchetgen, Eric Tchetgen; Haiman, Christopher; Hunter, David J; Plenge, Robert M; Worthington, Jane; Christiani, David C; Schaumberg, Debra A; Chasman, Daniel I; Altshuler, David; Voight, Benjamin; Kraft, Peter; Patterson, Nick; Price, Alkes L

    2012-01-01

    Genetic case-control association studies often include data on clinical covariates, such as body mass index (BMI), smoking status, or age, that may modify the underlying genetic risk of case or control samples. For example, in type 2 diabetes, odds ratios for established variants estimated from low-BMI cases are larger than those estimated from high-BMI cases. An unanswered question is how to use this information to maximize statistical power in case-control studies that ascertain individuals on the basis of phenotype (case-control ascertainment) or phenotype and clinical covariates (case-control-covariate ascertainment). While current approaches improve power in studies with random ascertainment, they often lose power under case-control ascertainment and fail to capture available power increases under case-control-covariate ascertainment. We show that an informed conditioning approach, based on the liability threshold model with parameters informed by external epidemiological information, fully accounts for disease prevalence and non-random ascertainment of phenotype as well as covariates and provides a substantial increase in power while maintaining a properly controlled false-positive rate. Our method outperforms standard case-control association tests with or without covariates, tests of gene x covariate interaction, and previously proposed tests for dealing with covariates in ascertained data, with especially large improvements in the case of case-control-covariate ascertainment. We investigate empirical case-control studies of type 2 diabetes, prostate cancer, lung cancer, breast cancer, rheumatoid arthritis, age-related macular degeneration, and end-stage kidney disease over a total of 89,726 samples. In these datasets, informed conditioning outperforms logistic regression for 115 of the 157 known associated variants investigated (P-value = 1 × 10(-9)). The improvement varied across diseases with a 16% median increase in χ(2) test statistics and a

  13. Survey research methods in evaluation and case-control studies.

    PubMed

    Kalton, Graham; Piesse, Andrea

    2007-04-15

    Survey research methods are widely used in two types of analytic studies: evaluation studies that measure the effects of interventions; and population-based case-control studies that investigate the effects of various risk factors on the presence of disease. This paper provides a broad overview of some design and analysis issues related to such studies, illustrated with examples. The lack of random assignment to treatment and control groups in many evaluation studies makes controlling for confounders critically important. Confounder control can be achieved by matching in the design and by various alternative methods in the analysis. One popular analytic method of controlling for confounders is propensity scoring, which bears a close resemblance to survey weighting. The use of population-based controls has become common in case-control studies. For reasons of cost, population-based controls are often identified by telephone surveys using random digit dialling (RDD) sampling methods. However, RDD surveys are now experiencing serious problems with response rates. A recent alternative approach is to select controls from frames such as driver license lists that contain valuable demographic information for use in matching. Methods of analysis developed in the survey sampling literature are applicable, at least to some degree, in the analyses of evaluation and population-based case-control studies. In particular, the effects of complex sample designs can be taken into account using survey sampling variance estimation methods. Several survey analysis software packages are available for carrying out the computations.

  14. Multiple Sclerosis Associated Risk Factors: A Case-Control Study

    PubMed Central

    POOROLAJAL, Jalal; MAZDEH, Mehrdokht; SAATCHI, Mohammad; TALEBI GHANE, Elaheh; BIDERAFSH, Azam; LOTFI, Bahar; FERYADRES, Mohammad; PAJOHI, Khabat

    2015-01-01

    Background: Hamadan Province is one of the high-risk regions in Iran for Multiple sclerosis (MS). A majority of the epidemiological studies conducted in Iran addressing MS are descriptive. This study was conducted to assess MS and its associated risk factors in Hamadan Province, the west of Iran. Methods: This case-control study compared 100 patients with MS (case group) and 100 patients with acute infectious diseases (control group) from September 2013 to March 2014. A checklist was used to assess the demographic, medical, and family history of the patients. The Friedman-Rosenman questionnaire was also used to assess personality type. Statistical analysis was performed using logistic regression model with Stata 11 software program. Results: The adjusted odds ratio (OR) estimate of MS was 4.37 (95% CI: 2.33, 8.20) for females compared to males; 0.15 (95% CI: 0.06, 0.43) for people aged above 50 years compared to aged 14 to 29 years; 0.44 (95% CI: 0.21, 0.91) for overweight or obese people compared to normal weights. Crude OR indicated a significant association between the occurrence of MS and exclusive breast feeding, season of birth, and smoking. However, the association was not statistically significant after adjustment for other covariates. Conclusion: The risk of MS is significantly lower in male gender, obese/overweight, and old people. Furthermore, non-smoking, non-exclusive breast-feeding, and born in autumn may increase the risk of MS but need further investigation. However, long-term large prospective cohort studies are needed to investigate the true effect of the potential risk factors on MS. PMID:26744707

  15. A case-control study of amyotrophic lateral sclerosis.

    PubMed

    Savettieri, G; Salemi, G; Arcara, A; Cassata, M; Castiglione, M G; Fierro, B

    1991-01-01

    A retrospective case-control study was conducted using 46 patients affected by amyotrophic lateral sclerosis and 92 closely matched healthy controls. Cases were ascertained through typical clinical and instrumental findings. Putative risk factors (bone fractures or major trauma, exposure to domestic animals, surgical operations, disease among first degree relatives and others) were investigated anamnestically using a standard questionnaire. Using Mantel-Haenzsel estimates of the odds ratio, no association was found between amyotrophic lateral sclerosis and the investigated variables.

  16. Non-Hodgkin's lymphoma: case control epidemiological study in Yorkshire.

    PubMed

    Cartwright, R A; McKinney, P A; O'Brien, C; Richards, I D; Roberts, B; Lauder, I; Darwin, C M; Bernard, S M; Bird, C C

    1988-01-01

    This paper reports the results of a case control study of non-Hodgkin's lymphoma in the Yorkshire Health Region. In all, 437 cases and 724 controls were interviewed. Risk factors associated with past skin conditions, family history of cancer and infectious mononucleosis, aspects of social life and contact with wood dust and epoxy glues all emerge. A comparison of high and low grade morphological forms of disease reveal contrasting risks and suggest separate aetiologies for these conditions.

  17. Female sexual dysfunction in androgenetic alopecia: Case-control study

    PubMed Central

    Sancak, Eyup Burak; Oguz, Sevilay; Akbulut, Tugba; Uludag, Aysegul; Akbas, Alpaslan; Kurt, Omer; Akbulut, Mehmet Fatih

    2016-01-01

    Introduction: We sought to evaluate the association of female sexual dysfunction (FSD) with androgenetic alopecia (AGA) and metabolic syndrome (MetS) in premenopausal women. Methods: From December 2013 to June 2015, we performed a case-control, prospective study of 115 patients with AGA and 97 age-matched control patients without AGA from among premenopausal women who visited dermatology clinics of the two reference hospitals. Comprehensive history, anthropometric measurements, and questionnaire administration were performed for each of the total of 212 women. The Female Sexual Function Index (FSFI) was used to assess the key dimensions of female sexual function. AGA was assessed and graded by an experienced dermatologist according to Ludwig’s classification. The MetS assessment was made according to the NCEP-ATP III criteria. Results: In univariate analysis, age, weight, waist circumference, hip circumference, waist-to-hip ratio, body mass index (BMI), AGA, MetS, cardiovascular event, marital status, hypertension, high fasting plasma glucose, high triglyceride, large waist, total testosterone, and free testosterone were associated with presence of FSD. In logistic regression analysis, age (odds ratio [OR] 1.21, 95% confidence interval [CI] 1.13–1.30; p<0.001), AGA (OR 3.42, 95% CI 1.31–8.94; p=0.017), MetS (OR 5.39, 95% CI 1.34–21.62; p=0.012), and free testosterone (OR 0.18, 95% CI 0.09–0.37; p<0.001) were independently associated with FSD. Conclusions: Our study suggests that age, AGA, MetS, and free testosterone may have strong impact on sexual function in premenopausal women. Further studies with population-based and longitudinal design should be conducted to confirm this finding. PMID:28255417

  18. [Case-control studies in psychiatry: causality, design and warnings].

    PubMed

    Silva Ayçaguer, L C

    2004-01-01

    This present paper is mainly methodological and has been written with the aim of helping researchers in psychiatry to produce results with higher quality and help readers to have adequate assessment values of others. Brief reflection is made on the most important conditions that must be fulfilled to prove a causality hypothesis, regardless of the investigation design used. However, the main purpose of the text is to examine and illustrate how these conditions work under a case-control study environment. Besides outlining the basic aspects concerning design and analysis, areas extremely illustrated with examples of case and controls in psychiatry found in the literature, a number of suggestions to avoid pitfalls that can invalidate research efforts developed using case-control methodology is offered.

  19. Nested case-control studies: should one break the matching?

    PubMed

    Borgan, Ørnulf; Keogh, Ruth

    2015-10-01

    In a nested case-control study, controls are selected for each case from the individuals who are at risk at the time at which the case occurs. We say that the controls are matched on study time. To adjust for possible confounding, it is common to match on other variables as well. The standard analysis of nested case-control data is based on a partial likelihood which compares the covariates of each case to those of its matched controls. It has been suggested that one may break the matching of nested case-control data and analyse them as case-cohort data using an inverse probability weighted (IPW) pseudo likelihood. Further, when some covariates are available for all individuals in the cohort, multiple imputation (MI) makes it possible to use all available data in the cohort. In the paper we review the standard method and the IPW and MI approaches, and compare their performance using simulations that cover a range of scenarios, including one and two endpoints.

  20. Metabolic Derangements in Lichen Planus - A Case Control Study

    PubMed Central

    Kar, Bikash Ranjan; Panda, Maitreyee

    2016-01-01

    Introduction An association between psoriasis and metabolic syndrome has been established in previous studies. Lichen Planus (LP) is also a chronic inflammatory disease morphologically related to psoriasis and few studies have shown association of metabolic derangements in LP. Aim To study the association of metabolic derangements in LP. Materials and Methods A prospective case control study was undertaken for a period of one year. Age and sex matched patients of LP and other non-inflammatory diseases were taken as cases and controls respectively. Data on height, weight, lipid profile and fasting blood glucose levels were collected for all the patients. Body Mass Index (BMI) was calculated. Results A total of 80 patients were recruited, 40 cases and 40 controls. The mean values for all the lipid and glucose parameters were high in cases as compared to controls with significant p-values. Conclusion In the present study metabolic derangements were seen in patients with LP. PMID:28050485

  1. Associations of aspirin, nonsteroidal anti-inflammatory drug and paracetamol use with PSA-detected prostate cancer: findings from a large, population-based, case-control study (the ProtecT study).

    PubMed

    Murad, Ali S; Down, Liz; Davey Smith, George; Donovan, Jenny L; Athene Lane, Janet; Hamdy, Freddie C; Neal, David E; Martin, Richard M

    2011-03-15

    Evidence from laboratory studies suggests that chronic inflammation plays an important role in prostate cancer aetiology. This has resulted in speculation that nonsteroidal anti-inflammatory drugs may protect against prostate cancer development. We analysed data from a cross-sectional case-control study (n(cases) = 1,016; n(controls) = 5,043), nested within a UK-wide population-based study that used prostate specific antigen (PSA) testing for identification of asymptomatic prostate cancers, to investigate the relationship of aspirin, nonsteroidal anti-inflammatory drug (NSAID) and paracetamol use with prostate cancer. In conditional logistic regression models accounting for stratum matching on age (5-year age bands) and recruitment centre, use of non-aspirin NSAIDs [odds ratio (OR) = 1.32; 95% confidence interval (CI): 1.04-1.67] or all NSAIDs (OR = 1.25; 95% CI = 1.07-1.47) were positively associated with prostate cancer. There were weaker, not conventionally statistically significant, positive associations of aspirin (OR = 1.13; 95% CI = 0.94-1.36) and paracetamol (OR = 1.20; 95% CI = 0.90-1.60) with prostate cancer. Mutual adjustment for aspirin, non-aspirin NSAIDs or paracetamol made little difference to these results. There was no evidence of confounding by age, family history of prostate cancer, body mass index or self-reported diabetes. Aspirin, NSAID and paracetamol use were associated with reduced serum PSA concentrations amongst controls. Our findings do not support the hypothesis that NSAIDs reduce the risk of PSA-detected prostate cancer. Our conclusions are unlikely to be influenced by PSA detection bias because the inverse associations of aspirin, NSAID and paracetamol use with serum PSA would have attenuated (not generated) the observed positive associations.

  2. Childhood cancer and overhead powerlines: a case-control study.

    PubMed Central

    Myers, A.; Clayden, A. D.; Cartwright, R. A.; Cartwright, S. C.

    1990-01-01

    A case-control study has been carried out to examine the occurrence of childhood cancer in relation to the proximity of overhead power lines to a child's home address at birth and to the calculated magnetic field at the address. The study included 374 cases diagnosed in the Yorkshire Health Region between 1970 and 1979, together with 588 matched controls. Magnetic-field strengths at the birth addresses due to the load currents of overhead power lines were calculated on the basis of line-network maps and load records. The results indicate no association between the occurrence of childhood malignancies and either the proximity or the magnetic fields of overhead lines, although the statistical power of the study was limited by the small numbers of children living close to overhead power lines. PMID:2257204

  3. Case Control Polysomnographic Studies of Sleep Disorders in Parkinson's Disease

    PubMed Central

    Yong, Ming-Hui; Fook-Chong, Stephanie; Pavanni, Ratnagopal; Lim, Li-Ling; Tan, Eng-King

    2011-01-01

    Background The relationship between a number of primary sleep disorders and Parkinson's disease (PD) is still debated. There are limited case control polysomnographic studies in PD and most of these study sample sizes are small. Methodology/Findings We conducted one of the largest case-control studies involving overnight polysomnographic evaluation, with prospective recruitment of unselected Parkinson's disease patients and healthy controls from an Asian population. The cases were recruited from the specialized movement disorder outpatient clinics in a tertiary referral center, and controls from the same geographical locations. All subjects underwent an overnight polysomnographic study and a multiple sleep latency test. A total of 124 subjects including 56 patients and 68 controls frequency-matched for age and sex were included. Multivariate analysis revealed that patients had significantly shorter total sleep time than controls (p = 0.01), lower sleep efficiency (p = 0.001) and increased REM latency (p = 0.007). In patients, multivariate analysis showed that reduced total sleep time was significantly associated with increased age (p = 0.001) and increased levodopa dose (p = 0.032). The mean Insomnia Severity Index was higher in PD patients (9.0±7.1) compared to controls (3.3±3.9, p<0.001). The mean Epworth Sleepiness Scale score was higher in PD patients (9.3±5.9 vs. 5.7±4.8, p<0.001). Nocturnal arousals, obstructive sleep apnea, periodic leg movements and objective abnormal sleepiness were not increased in our patients. Conclusions/Significance Our case-control polysomnographic study, the first-ever performed in an Asian population, revealed altered sleep architecture and reduced sleep in PD patients compared to controls. Reduced total sleep time was associated with increased age and levodopa dose. However, nocturnal arousals, primary sleep disorders and abnormal sleepiness were not increased in our PD patients suggesting that ethnic

  4. A general regression framework for a secondary outcome in case-control studies.

    PubMed

    Tchetgen Tchetgen, Eric J

    2014-01-01

    Modern case-control studies typically involve the collection of data on a large number of outcomes, often at considerable logistical and monetary expense. These data are of potentially great value to subsequent researchers, who, although not necessarily concerned with the disease that defined the case series in the original study, may want to use the available information for a regression analysis involving a secondary outcome. Because cases and controls are selected with unequal probability, regression analysis involving a secondary outcome generally must acknowledge the sampling design. In this paper, the author presents a new framework for the analysis of secondary outcomes in case-control studies. The approach is based on a careful re-parameterization of the conditional model for the secondary outcome given the case-control outcome and regression covariates, in terms of (a) the population regression of interest of the secondary outcome given covariates and (b) the population regression of the case-control outcome on covariates. The error distribution for the secondary outcome given covariates and case-control status is otherwise unrestricted. For a continuous outcome, the approach sometimes reduces to extending model (a) by including a residual of (b) as a covariate. However, the framework is general in the sense that models (a) and (b) can take any functional form, and the methodology allows for an identity, log or logit link function for model (a).

  5. A case-control study of Alzheimer's disease in Australia.

    PubMed

    Broe, G A; Henderson, A S; Creasey, H; McCusker, E; Korten, A E; Jorm, A F; Longley, W; Anthony, J C

    1990-11-01

    We conducted a case-control study of clinically diagnosed Alzheimer's disease (AD) on 170 cases aged 52 to 96 years, and 170 controls matched for age, sex and, where possible, the general practice of origin. Trained lay interviewers naive to the hypotheses and to the clinical status of the elderly person carried out risk-factor interviews with informants. Significant odds ratios were found for 4 variables: a history of either dementia, probable AD, or Down's syndrome in a 1st-degree relative, and underactivity as a behavioral trait in both the recent and more distant past. Previously reported or suggested associations not confirmed by this study include head injury, starvation, thyroid disease, analgesic abuse, antacid use (aluminum exposure), alcohol abuse, smoking, and being left-handed.

  6. Hodgkin's disease: case control epidemiological study in Yorkshire.

    PubMed Central

    Bernard, S. M.; Cartwright, R. A.; Darwin, C. M.; Richards, I. D.; Roberts, B.; O'Brien, C.; Bird, C. C.

    1987-01-01

    This is the first report of a case-control epidemiological study on lymphomas and leukaemias occurring in Yorkshire during 1979-84. This paper deals with the results of the Hodgkin's disease analysis comprising 248 cases and 489 controls. The results indicate support for previous work with respect to small family size and past history of infectious mononucleosis. Positive observations made in a previous pilot study are also confirmed and extended with respect to associations with certain chronic skin lesions, dental anaesthesia and familial factors. Negative associations are described with respect to X-ray exposures and cigarette smoking. It is proposed that these results fit into a general hypothesis that these conditions are the result of interaction between infectious agents and altered immunity in those persons genetically predisposed. PMID:3814482

  7. Hodgkin's disease: case control epidemiological study in Yorkshire.

    PubMed

    Bernard, S M; Cartwright, R A; Darwin, C M; Richards, I D; Roberts, B; O'Brien, C; Bird, C C

    1987-01-01

    This is the first report of a case-control epidemiological study on lymphomas and leukaemias occurring in Yorkshire during 1979-84. This paper deals with the results of the Hodgkin's disease analysis comprising 248 cases and 489 controls. The results indicate support for previous work with respect to small family size and past history of infectious mononucleosis. Positive observations made in a previous pilot study are also confirmed and extended with respect to associations with certain chronic skin lesions, dental anaesthesia and familial factors. Negative associations are described with respect to X-ray exposures and cigarette smoking. It is proposed that these results fit into a general hypothesis that these conditions are the result of interaction between infectious agents and altered immunity in those persons genetically predisposed.

  8. Leptospira Exposure and Gardeners: A Case-Control Seroprevalence Study

    PubMed Central

    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

  9. Case-control study of dementia of the Alzheimer type

    SciTech Connect

    French, L.R.; Schuman, L.M.; Mortimer, J.A.; Hutton, J.T.; Boatman, R.A.; Christians, B.

    1985-03-01

    A case-control study to assess factors of possible etiologic significance to dementia of the Alzheimer type was conducted with 78 male cases diagnosed in 1979-1982 at the Veterans Administration Medical Center in Minneapolis, Minnesota and age-race-sex-matched hospital and neighborhood controls (14 of 16 autopsied cases were histopathologically confirmed). Information was obtained on variables relevant to vital, genetic, and immunologic hypotheses, and on possible occupational and environmental exposures, drug use, psychologic stress, smoking, and alcohol consumption. The only major difference between patients with dementia of the Alzheimer type and controls was a significantly greater occurrence of antecedent head trauma in the patients (odds ratio = 4.50). This finding is consistent with the literature on posttraumatic dementia but its importance is presently unclear.

  10. Informed Conditioning on Clinical Covariates Increases Power in Case-Control Association Studies

    PubMed Central

    Zaitlen, Noah; Lindström, Sara; Pasaniuc, Bogdan; Cornelis, Marilyn; Genovese, Giulio; Pollack, Samuela; Barton, Anne; Bickeböller, Heike; Bowden, Donald W.; Eyre, Steve; Freedman, Barry I.; Friedman, David J.; Field, John K.; Groop, Leif; Haugen, Aage; Heinrich, Joachim; Henderson, Brian E.; Hicks, Pamela J.; Hocking, Lynne J.; Kolonel, Laurence N.; Landi, Maria Teresa; Langefeld, Carl D.; Le Marchand, Loic; Meister, Michael; Morgan, Ann W.; Raji, Olaide Y.; Risch, Angela; Rosenberger, Albert; Scherf, David; Steer, Sophia; Walshaw, Martin; Waters, Kevin M.; Wilson, Anthony G.; Wordsworth, Paul; Zienolddiny, Shanbeh; Tchetgen, Eric Tchetgen; Haiman, Christopher; Hunter, David J.; Plenge, Robert M.; Worthington, Jane; Christiani, David C.; Schaumberg, Debra A.; Chasman, Daniel I.; Altshuler, David; Voight, Benjamin; Kraft, Peter; Patterson, Nick; Price, Alkes L.

    2012-01-01

    Genetic case-control association studies often include data on clinical covariates, such as body mass index (BMI), smoking status, or age, that may modify the underlying genetic risk of case or control samples. For example, in type 2 diabetes, odds ratios for established variants estimated from low–BMI cases are larger than those estimated from high–BMI cases. An unanswered question is how to use this information to maximize statistical power in case-control studies that ascertain individuals on the basis of phenotype (case-control ascertainment) or phenotype and clinical covariates (case-control-covariate ascertainment). While current approaches improve power in studies with random ascertainment, they often lose power under case-control ascertainment and fail to capture available power increases under case-control-covariate ascertainment. We show that an informed conditioning approach, based on the liability threshold model with parameters informed by external epidemiological information, fully accounts for disease prevalence and non-random ascertainment of phenotype as well as covariates and provides a substantial increase in power while maintaining a properly controlled false-positive rate. Our method outperforms standard case-control association tests with or without covariates, tests of gene x covariate interaction, and previously proposed tests for dealing with covariates in ascertained data, with especially large improvements in the case of case-control-covariate ascertainment. We investigate empirical case-control studies of type 2 diabetes, prostate cancer, lung cancer, breast cancer, rheumatoid arthritis, age-related macular degeneration, and end-stage kidney disease over a total of 89,726 samples. In these datasets, informed conditioning outperforms logistic regression for 115 of the 157 known associated variants investigated (P-value = 1×10−9). The improvement varied across diseases with a 16% median increase in χ2 test statistics and a

  11. Consanguinity and Neonatal Death: A Nested Case-Control Study

    PubMed Central

    Chaman, Reza; Gholami Taramsari, Mahshid; Khosravi, Ahmad; Amiri, Mohammad; Holakouie Naieni, Kourosh; Yunesian, Masoud

    2014-01-01

    Objective: Although numerous studies have found higher rates of abortion and still births following consanguinity (familial marriages), the question of whether consanguinity significantly increases the risk of neonatal death has inadequately been addressed.This study aims to evaluate familial marriage effects on neonatal death in rural areas in Iran. Materials and methods: In this nested case-control study, 6900 newbornswho were born in rural areas of Kohgiluyeh and Boyerahmad Province (South-West of Iran)were followed till the end of neonatal period, and neonatal death was the outcome of interest. Subsequently 97 cases and 97 controls were selected in study cohort by using risk set sampling model. Crude and adjusted odds ratios (OR) were estimated by usinga conditional logistic regression model. Results: In the final model, prematurity (OR = 5.57), low birthweight (LBW) (OR = 7.68), consanguinity (first cousins) (OR = 5.23), C-section (OR = 7.27), birth rank more than 3 (OR = 6.95) and birthsinterval less than 24 months (OR = 4.65) showed significant statistical association with neonatal mortality (p < 0.05). Conclusion: According to our findings, after adjusting the effects of other significant risk factors, familial marriageto first cousins is considered asan important risk factor for neonatal death. PMID:25530772

  12. Neurocysticercotic Calcifications and Hippocampal Sclerosis: A Case-Control Study

    PubMed Central

    Yasuda, Clarissa Lin; Coan, Ana Carolina; Secolin, Rodrigo; Luiz Cunha da Costa, Alberto; Cendes, Fernando

    2015-01-01

    Objective The exact role of calcified neurocysticercotic lesions (CNLs) in epilepsy is yet unknown and controversial. Although the relationship between CNLs, epilepsy and mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) has already been addressed, to our knowledge, no study has actually provided strong statistical evidence, nor reported the ODDS ratio for these associations. Therefore, we designed this case-control study to assess the likelihood of having MTLE-HS versus other forms of epilepsy in the presence of CNLs. Methods In this case-control study we included 119 consecutive patients with epilepsy and 106 disease controls (headache) with previous CT scans. We subdivided cases into MTLE-HS and other epilepsies. We used brain CT scans to define presence or absence of CNLs. After exploratory analyses, we used logistic regression to analyze the association between CNLs, epilepsy subgroups and disease controls. Results CNLs were found in 31.09% of cases and in 11.32% of controls (p<0.001). The initial analysis comparing epilepsy versus controls revealed a significant association between CNLs and epilepsy (OR = 5.32; 95%CI = 2.43-11.54; p<0.001). However, when we compared MTLE-HS versus other epilepsies versus controls we confirmed that CNLs were associated with MTLE-HS (OR = 11.27, 95%CI = 4.73-26.85; p<0.001) but other epilepsies were not. We found no difference in the CNLs load and no difference in the location of the CNLs when we compared patients with MTLE-HS, other epilepsies and disease controls. Significance The inclusion of controls allowed us to estimate the likelihood of having epilepsy in the presence of CNLs. We found that patients with CNLs were 11 times more likely to have MTLE-HS; however, the presence of CNLs did not change the odds of having other types of epilepsy. These findings raise the possibility of neurocysticercosis playing a role in the pathophysiology of MTLE-HS and need further confirmation in other series. PMID

  13. The limitations of case-control studies in the detection of environmental carcinogens.

    PubMed Central

    Crombie, I K

    1981-01-01

    The ability of the case-control study to detect human carcinogens has been investigated theoretically for varying fractions of the population exposed to hazards carrying different relative risks. The method is shown to be useful for the investigation of factors to which exposure is widespread (for example, common foods or beverages) but it is of limited use for the study of uncommon types of exposure, such as those associated with occupation. The case-control study is unable to detect very small relative risks (less than 1.5) even where exposure is widespread and large numbers of cases of cancer are occurring in the population. The principal limitation of the method is the maximum number of cases which can be recruited and analysed. It will only be through large-scale collaborative multicentre or international studies that important risk factors will be detected. PMID:7338704

  14. Nonparametric Bayes modeling for case control studies with many predictors.

    PubMed

    Zhou, Jing; Herring, Amy H; Bhattacharya, Anirban; Olshan, Andrew F; Dunson, David B

    2016-03-01

    It is common in biomedical research to run case-control studies involving high-dimensional predictors, with the main goal being detection of the sparse subset of predictors having a significant association with disease. Usual analyses rely on independent screening, considering each predictor one at a time, or in some cases on logistic regression assuming no interactions. We propose a fundamentally different approach based on a nonparametric Bayesian low rank tensor factorization model for the retrospective likelihood. Our model allows a very flexible structure in characterizing the distribution of multivariate variables as unknown and without any linear assumptions as in logistic regression. Predictors are excluded only if they have no impact on disease risk, either directly or through interactions with other predictors. Hence, we obtain an omnibus approach for screening for important predictors. Computation relies on an efficient Gibbs sampler. The methods are shown to have high power and low false discovery rates in simulation studies, and we consider an application to an epidemiology study of birth defects.

  15. Occupation and breast cancer: a Canadian case-control study.

    PubMed

    Brophy, James T; Keith, Margaret M; Gorey, Kevin M; Luginaah, Isaac; Laukkanen, Ethan; Hellyer, Deborah; Reinhartz, Abraham; Watterson, Andrew; Abu-Zahra, Hakam; Maticka-Tyndale, Eleanor; Schneider, Kenneth; Beck, Matthias; Gilbertson, Michael

    2006-09-01

    A local collaborative process was launched in Windsor, Ontario, Canada to explore the role of occupation as a risk factor for cancer. An initial hypothesis-generating study found an increased risk for breast cancer among women aged 55 years or younger who had ever worked in farming. On the basis of this result, a 2-year case-control study was undertaken to evaluate the lifetime occupational histories of women with breast cancer. The results indicate that women with breast cancer were nearly three times more likely to have worked in agriculture when compared to the controls (OR = 2.80 [95% CI, 1.6-4.8]). The risk for those who worked in agriculture and subsequently worked in automotive-related manufacturing was further elevated (OR = 4.0 [95% CI, 1.7-9.9]). The risk for those employed in agriculture and subsequently employed in health care was also elevated (OR = 2.3 [95% CI, 1.1-4.6]). Farming tended to be among the earlier jobs worked, often during adolescence. While this article has limitations including the small sample size and the lack of information regarding specific exposures, it does provide evidence of a possible association between farming and breast cancer. The findings indicate the need for further study to determine which aspects of farming may be of biological importance and to better understand the significance of timing of exposure in terms of cancer risk.

  16. Nutrient patterns and asthenozoospermia: a case-control study.

    PubMed

    Eslamian, G; Amirjannati, N; Rashidkhani, B; Sadeghi, M-R; Hekmatdoost, A

    2017-04-01

    The association of dietary nutrient patterns and sperm motility is not yet well elucidated, and previous studies have just focused on the isolated nutrients. This case-control study examined the association of nutrient patterns with asthenozoospermia among Iranian men. In total, 107 incident asthenozoospermic men and 235 age-matched controls were interviewed through the infertility clinics in Tehran, Iran, from January 2012 to November 2013. Semen quality data were analysed according to the fifth edition of WHO guideline. Nutrient patterns were identified using principal component analysis based on semiquantitative 168-item food frequency questionnaires. All nutrient intakes were energy-adjusted by the residual method. In principal component analysis, three dietary patterns emerged. The first pattern, which was high in vitamin E, vitamin D, vitamin C, zinc, folate, total fibre, selenium and polyunsaturated fatty acids, was significantly associated with lower risk of asthenozoospermia. After adjustment for potential confounders, participants in the highest tertile of the first pattern scores had 51% lower risk of asthenozoospermia compared with those in the lowest (p-trend: .004). Our findings suggest that adherence to the pattern comprising mainly of antioxidant nutrients may be inversely associated with asthenozoospermia.

  17. Violence against Women and Gastroschisis: A Case-Control Study

    PubMed Central

    Ortega-García, Juan Antonio; Soldin, Offie P.; Sánchez-Sauco, Miguel Felipe; Cánovas-Conesa, Alicia; Gomaríz-Peñalver, Virtudes; Jaimes-Vega, Diana Carolina; Perales, Joseph E.; Cárceles-Alvarez, Alberto; Martínez-Ros, Maria Teresa; Ruiz, Daniel

    2013-01-01

    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. PMID:24142184

  18. Periodontal disease and spontaneous preterm birth: a case control study

    PubMed Central

    Wood, Stephen; Frydman, Albert; Cox, Stephen; Brant, Rollin; Needoba, Sheilia; Eley, Barry; Sauve, Reg

    2006-01-01

    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 <35 weeks gestation. Two groups of controls (n = 101) were recruited: women who were undelivered but at a preterm gestation and women who delivered at term. A standard, clinical, periodontal examination was performed and gingival crevicular fluid was obtained from standardized locations and tested for neutrophil elastase along with the bacterial enzymes gingipain and dipeptidylpeptidase. Data were analyzed with Fisher's exact tests, ANOVA and multivariate logistic regression. 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. PMID:16848912

  19. Sequential tests for gene-environment interactions in matched case-control studies.

    PubMed

    Tweel, Ingeborg van der; Schipper, Maria

    2004-12-30

    The sample size necessary to detect a significant gene x environment interaction in an observational study can be large. For reasons of cost-effectiveness and efficient use of available biological samples we investigated the properties of sequential designs in matched case-control studies to test for both non-hierarchical and hierarchical interactions. We derived the test statistics Z and V and their characteristics when applied in a two-sided triangular test. Results of simulations show good agreement with theoretical values for V and the type I error. Power values were larger than their theoretical values for very large sample sizes. Median gain in efficiency was about 27 per cent. For a 'rare' phenotype gain in efficiency was larger when the alternative hypothesis was true than under the null hypothesis. Sequential designs lead to substantial efficiency gains in tests for interaction in matched case-control studies.

  20. Association between diabetes and tuberculosis: case-control study

    PubMed Central

    Pereira, Susan Martins; de Araújo, Gleide Santos; Santos, Carlos Antônio de Souza Teles; de Oliveira, Maeli Gomes; Barreto, Maurício Lima

    2016-01-01

    ABSTRACT OBJECTIVE To test the association between diabetes and tuberculosis. METHODS It is a case-control study, matched by age and sex. We included 323 new cases of tuberculosis with positive results for bacilloscopy. The controls were 323 respiratory symptomatic patients with negative bacilloscopy, from the same health services, such as: ambulatory cases from three referral hospitals and six basic health units responsible for the notifications of new cases of tuberculosis in Salvador, Bahia. Data collection occurred between 2008 and 2010. The instruments used were structured interview, including clinical data, capillary blood glucose (during fasting or postprandial), and the CAGE questionnaire for screening of abusive consumption of alcohol. Descriptive, exploratory, and multivariate analysis was performed using conditional logistic regression. RESULTS The average age of the cases was 38.5 (SD = 14.2) years and of the controls, 38.5 (SD = 14.3) years. Among cases and controls, most subjects (61%) were male. In univariate analysis we found association between the occurrence of diabetes and tuberculosis (OR = 2.37; 95%CI 1.04–5.42), which remained statistically significant after adjustment for potential confounders (OR = 3.12; 95%CI 1.12–7.94). CONCLUSIONS The association between diabetes and tuberculosis can hinder the control of tuberculosis, contributing to the maintainance of the disease burden. The situation demands increasing early detection of diabetes among people with tuberculosis, in an attempt to improve disease control strategies. PMID:28099656

  1. A case-control study of gastric cancer in Venezuela.

    PubMed

    Muñoz, N; Plummer, M; Vivas, J; Moreno, V; De Sanjosé, S; Lopez, G; Oliver, W

    2001-08-01

    A case-control study to evaluate risk factors for gastric cancer was carried out among 292 cases of gastric cancer and 485 controls in a high-risk area of Venezuela. Subjects were interviewed using a structured questionnaire, which elicited information on residential history, socio-economic status, family history of gastric diseases, smoking, drinking and dietary habits. Habitual diet was estimated from a meal-structured food frequency questionnaire on 75 food items. There was a strong inverse association with social class, as measured by education and by indicators of poverty. The results of the dietary analysis suggest that a diet high in starch and low in meat, fish and fresh vegetables increases risk of gastric cancer. A protective effect was observed for frequent consumption of allium vegetables. Inverse associations were found with height, which may reflect nutritional status in childhood, and with refrigerator use in the first two decades of life. Alcohol and tobacco consumption was investigated among males only, since the prevalence of alcohol and tobacco use was very low in females. Alcohol drinkers were at higher risk than non-drinkers and there was a small excess risk for current smokers compared with never smokers. There was some evidence of familial aggregation of gastric cancer. These findings will have important implications in planning preventive strategies for gastric cancer in Venezuela.

  2. Smoking, the environment and meningococcal disease: a case control study.

    PubMed Central

    Stanwell-Smith, R. E.; Stuart, J. M.; Hughes, A. O.; Robinson, P.; Griffin, M. B.; Cartwright, K.

    1994-01-01

    This case control study investigated environmental factors in 74 confirmed cases of meningococcal disease (MD). In children aged under 5, passive smoking in the home (30 or more cigarettes daily) was associated with an odds ratio (OR) of 7.5 (95% confidence interval (CI) 1.46-38.66). ORs increased both with the numbers of cigarettes smoked and with the number of smokers in the household, suggesting a dose-response relationship. MD in this age group was also significantly associated with household overcrowding (more than 1.5 persons per room) (OR 6.0, 95% CI 1.10-32.8), with kisses on the mouth with 4 or more contacts in the previous 2 weeks (OR 2.46, 95% CI 1.09-5.56), with exposure to dust from plaster, brick or stone in the previous 2 weeks (OR 2.24, 95% CI 1.07-4.65); and with changes in residence (OR 3.0, 95% CI 1.0-8.99), marital arguments (OR 3.0, 95% CI 1.26-7.17) and legal disputes in the previous 6 months (OR 3.10, 95% CI 1.24-7.78). These associations were independent of social class. Public health measures to lower the prevalence of cigarette smoking by parents of young children may reduce the incidence of MD. The influence of building dust and stressful life events merits further investigation. PMID:8150006

  3. Tumor diagnosis preceding Parkinson's disease: a case-control study.

    PubMed

    D'Amelio, Marco; Ragonese, Paolo; Morgante, Letterio; Epifanio, Antonio; Callari, Graziella; Salemi, Giuseppe; Savettieri, Giovanni

    2004-07-01

    Lower cancer risk in Parkinson's disease (PD) patients compared to the general population has been reported. However, most of the studies were based on death certificates. We designed a case-control study to estimate the association of tumor preceding PD onset and PD. PD patients were matched by age and gender to PD-free individuals, randomly selected from the municipalities of residence of cases. Occurrence of tumors preceding PD onset was assessed through a structured questionnaire. Neoplasms were categorized as benign, malignant, or of uncertain classification, and endocrine-related or not. Odds ratios (OR) were calculated using conditional logistic regression and adjusted for tumor categories and risk factors. We included 222 PD patients. Frequency of cancer was 6.8% for cases, 12.6% for controls. PD patients had a decreased risk for neoplasms (adjusted OR, 0.4; 95% confidence interval [CI], 0.2-0.7). Risk was reduced only for women (adjusted OR, 0.3; 95% CI, 0.1-0.7). PD patients had a decreased risk both for malignant (adjusted OR, 0.6; 95% CI, 0.1-2.5) and nonmalignant neoplasms (adjusted OR, 0.3; 95% CI, 0.1-0.7). Still, risk was decreased for endocrine-related tumors (adjusted OR, 0.3; 95% CI, 0.1-0.9) and non-endocrine-related tumors (adjusted OR, 0.4; 95% CI, 0.1-0.9). Our study confirms the inverse association between PD and neoplasms reported in previous epidemiologic studies.

  4. Surgical site infections in breast surgery: case-control study.

    PubMed

    Vilar-Compte, Diana; Jacquemin, Benedicte; Robles-Vidal, Carlos; Volkow, Patricia

    2004-03-01

    The purpose of this study was to estimate the frequency of surgical site infections (SSIs) and identify associated risk factors for each type of breast surgery at a cancer hospital. We used a nested case-control design. Between February 1, 2000 and July 31, 2000, all breast surgeries performed were recorded on a daily basis. After hospital discharge, we evaluated patients simultaneously with surgeons three times a week for 30 days or longer. The odds ratio (OR) was estimated using logistic regression analysis. The study followed 280 patients (298 wounds). Altogether, 77 SSIs were detected, for an overall SSI rate of 25.8% (77/298). For excisions, conservative surgery, and radical mastectomies the SSI rates were 1.4%, 18.0%, and 38.3%, respectively. Excisions were excluded ( n = 68) for risk factor analysis. After multivariate analysis, risk factors associated with SSIs were obesity [OR 2.5, 95% confidence interval (CI) 1.2-4.3], concomitant chemotherapy and radiation (OR 2.3, 95% CI 1.2-4.3), radical surgery (OR 3.1, 95% CI 1.1-8.6), insertion of a second drain during the late postoperative period (OR 3.7, 95% CI 1.8-7.8), and drainage duration > or = 19 days (OR 2.9, 95% CI 1.5-5.6). The bacteria most frequently isolated were Pseudomonas aeruginosa ( n = 18 ), Serratia sp. ( n = 18), Staphylococcus aureus ( n = 10), and Staphylococcus epidermidis ( n = 10). Poor compliance with infection control practices and wound management was detected throughout the study period. The overall frequency of SSIs for mastectomies was higher than the reported rates, which was principally related to the more radical surgery required for advanced-stage disease, preoperative irradiation, and inadequate wound and drain care.

  5. Occupational Risk Factors for COPD: A Case-Control Study

    PubMed Central

    Drame, Moustapha; Lebargy, Francois; Deschamps, Frédéric

    2016-01-01

    Objectives The aim of this research was to examine the occupational risk factors for Chronic Obstructive Pulmonary Diseases (COPD) in a range of occupations. Methods Eleven occupations involving different types of exposure were observed in this multicenter case-control study. Controls and cases were matched for sex, age and smoking. Multiple logistic regression analyses were used to estimate odds ratios (ORs). Results A total of 1,519 participants were initially recruited between September 2004 and September 2012. After matching, 547 pairs were obtained. The mean age was 56.3 +/- 10.4 years. Smelter workers were the only ones with an increased risk of COPD in this study (OR = 7.6, p < 0.0001, 95% CI [4.5, 12.9]). Physical activity was protective (OR = 0.7), while living in the city was a risk (OR = 1.6). The main used metals were cast iron, aluminum and alloys. Molds and cores were mainly made from sand and synthetic resins. Machine maintenance (65.2%), molding (49.6%), finishing (41.1%) and casting (41.0%) were the most common activities. Almost all workers (95.1%) cleaned the floors and machines with a brush or compressed air. Conclusions This study demonstrates the importance of occupational factors in the genesis of COPD, especially among smelter workers. As with the fight against smoking-related disease, the removal or substitution of recognized hazardous agents is the best way of preventing the onset of COPD. This is why it is essential to continue research on its occupational risk factors. PMID:27487078

  6. Risk factors for psoriasis: A case-control study.

    PubMed

    Jankovic, Slavenka; Raznatovic, Milena; Marinkovic, Jelena; Jankovic, Janko; Maksimovic, Natasa

    2009-06-01

    A case-control study of 110 consecutive psoriatic outpatients and 200 unmatched controls was carried out in order to analyze the association of psoriasis with smoking habits, alcohol consumption, family history of psoriasis and stressful life events. Stressful life events were assessed with Paykel's Interview for Recent Life Events, a semi-structured interview covering 63 life events. According to our results, the risk of psoriasis is higher in urban dwellers (odds ratio [OR] = 3.61; 95% confidence interval [CI] = 0.99-13.18), patients who were divorced (OR = 5.69; 95% CI = 2.26-14.34) and those exposed to environmental tobacco smoke at home (OR = 2.29; 95% CI = 1.12-4.67). Alcohol consumption (OR = 2.55; 95% CI = 1.26-5.17), family history of psoriasis (OR = 33.96; 95% CI = 14.14-81.57) and change in work conditions (OR = 8.34; 95% CI = 1.86-37.43) are also risk factors for psoriasis. Separate analyses for men and women showed that the risk of developing psoriasis was stronger in men with a family history of psoriasis (OR = 30.39; 95% CI = 6.72-137.42) than in women (OR = 16.99; 95% CI = 7.21-40.07). The effect of environmental tobacco smoke at home was found only in women (OR = 2.44; 95% CI = 1.26-4.73). Future well-designed epidemiological studies need to be performed in order to determine whether lifestyle factors and stress could be risk factors triggering or aggravating psoriasis.

  7. Facial dermatosis associated with Demodex: a case-control study.

    PubMed

    Zhao, Ya-e; Peng, Yan; Wang, Xiang-lan; Wu, Li-ping; Wang, Mei; Yan, Hu-ling; Xiao, Sheng-xiang

    2011-12-01

    Demodex has been considered to be related with multiple skin disorders, but controversy persists. In this case-control study, a survey was conducted with 860 dermatosis patients aged 12 to 84 years in Xi'an, China to identify the association between facial dermatosis and Demodex. Amongst the patients, 539 suffered from facial dermatosis and 321 suffered from non-facial dermatosis. Demodex mites were sampled and examined using the skin pressurization method. Multivariate regression analysis was applied to analyze the association between facial dermatosis and Demodex infestation, and to identify the risk factors of Demodex infestation. The results showed that total detection rate of Demodex was 43.0%. Patients aged above 30 years had higher odds of Demodex infestation than those under 30 years. Compared to patients with neutral skin, patients with mixed, oily, or dry skin were more likely to be infested with Demodex (odds ratios (ORs) were 2.5, 2.4, and 1.6, respectively). Moreover, Demodex infestation was found to be statistically associated with rosacea (OR=8.1), steroid-induced dermatitis (OR=2.7), seborrheic dermatitis (OR=2.2), and primary irritation dermatitis (OR=2.1). In particular, ORs calculated from the severe infestation (≥5 mites/cm(2)) rate were significantly higher than those of the total rate. Therefore, we concluded that Demodex is associated with rosacea, steroid-induced dermatitis, seborrheic dermatitis, and primary irritation dermatitis. The rate of severe infestation is found to be more correlated with various dermatosis than the total infestation rate. The risk factors of Demodex infestation, age, and skin types were identified. Our study also suggested that good hygiene practice might reduce the chances of demodicosis and Demodex infestation.

  8. Hyperhomocysteinemia among Omani autistic children: a case-control study.

    PubMed

    Ali, Amanat; Waly, Mostafa I; Al-Farsi, Yahya M; Essa, Musthafa M; Al-Sharbati, Marwan M; Deth, Richard C

    2011-01-01

    High serum homocysteine (Hcy) level is regarded as an indicator for impairment of folate-dependent methionine cycle and is associated with oxidative stress. In a case control study, we evaluated eighty 3-5 years old Omani children (40 diagnosed with Autism Spectrum Disorder and 40 their age and gender matched controls) for their fasting serum homocysteine levels as a biomarker of Autism Spectrum Disorder (ASD). Serum folate and vitamin B(12) status were also evaluated. The serum homocysteine was measured using an enzyme immunoassay (EIA) technique whereas folate and vitamin B(12) were measured using an automated random access immune-assay system. The results indicated that mean serum Hcy levels were significantly (P < 0.05) higher in autistic children (20.1 ± 3.3 µmol/L) as compared to controls (9.64 ± 2.1 µmol/L). Significantly (P < 0.05) lower serum folate (1.8 ± 0.4 µg/L) and vitamin B(12) (191.1 ± 0.9 pg/mL) levels were observed in autistic children as compared to controls (6.1 ± 0.6 µg/L and 288.9 ± 1.3 pg/mL, respectively). The levels of homocysteine in autistic children were also much higher as compared to normal reference values (5-15 µmol/L). The results suggest that high fasting serum homocysteine and low folate and vitamin B(12) levels could be used as clinical biomarkers for an early diagnosis and management of ASD.

  9. Toxocariasis in Waste Pickers: A Case Control Seroprevalence Study

    PubMed Central

    Alvarado-Esquivel, Cosme

    2013-01-01

    Background The epidemiology of Toxocara infection in humans in Mexico has been poorly explored. There is a lack of information about Toxocara infection in waste pickers. Aims Determine the seroepidemiology of Toxocara infection in waste pickers. Methods Through a case control study design, the presence of anti-Toxocara IgG antibodies was determined in 90 waste pickers and 90 age- and gender-matched controls using an enzyme-linked immunoassay. Associations of Toxocara exposure with socio-demographic, work, clinical, and behavioral data of the waste pickers were also evaluated. Results The seroprevalence of anti-Toxocara IgG antibodies was significantly higher in waste pickers (12/90: 13%) than in control subjects (1/90: 1%) (OR  = 14; 95% CI: 2–288). The seroprevalence was not influenced by socio-demographic or work characteristics. In contrast, increased seroprevalence was found in waste pickers suffering from gastritis, and reflex and visual impairments. Multivariate analysis showed that Toxocara exposure was associated with a low frequency of eating out of home (OR  = 26; 95% CI: 2–363) and negatively associated with consumption of chicken meat (OR  = 0.03; 95% CI: 0.003–0.59). Other behavioral characteristics such as animal contacts or exposure to soil were not associated with Toxocara seropositivity. Conclusions 1) Waste pickers are a risk group for Toxocara infection. 2) Toxocara is impacting the health of waste pickers. This is the first report of Toxocara exposure in waste pickers and of associations of gastritis and reflex impairment with Toxocara seropositivity. Results warrant for further research. PMID:23349987

  10. Acromegalic axial arthropathy: a clinical case-control study.

    PubMed

    Scarpa, Raffaele; De Brasi, Davide; Pivonello, Rosario; Marzullo, Paolo; Manguso, Francesco; Sodano, Antonio; Oriente, Pasquale; Lombardi, Gaetano; Colao, Annamaria

    2004-02-01

    Arthropathy is the major cause of morbidity in acromegaly. To feature the spinal involvement, 54 patients with active acromegaly (27 men, 27 women; age range, 21-69 yr) and 54 sex-, age-, and body mass index-matched healthy controls were enrolled in this observational analytical prospective case-control study. A questionnaire to describe onset, duration, and severity of articular symptoms; rheumatological examination, including vertebral and chest mobility, Schober test, thorax expansion, and axial radiological study; and IGF-I, GH, insulin, and glucose level measurement (baseline and after an oral glucose tolerance test) was used to investigate the prevalence of arthropathy and correlate these findings with hormonal parameters. Axial arthropathy was found in 28 patients (52%) and 12 controls (22%; chi(2) = 8.9; P = 0.003). In detail, spinal mobility was reduced in 30 patients (56%) and 10 controls (18%; chi(2) = 14.3; P < 0.0001), thoracic cage was involved in six patients (11%), alterations of spinal profile were observed in 37 patients (68%) and 15 controls (28%; chi(2) = 16.3; P < 0.0001), and increased L2 vertebra diameters were observed in 34 patients (63%) and none of the controls (chi(2) = 46.7; P < 0.0001). Narrowing and widening of L2-L3 disk space were found in 20 (37%) and seven (13%) patients, respectively. Features of diffuse idiopathic skeletal hyperostosis (DISH) were found in 11 patients (20%) and none of the controls (chi(2) = 10.1; P < 0.001). Disease duration was correlated with vertebral body height (P = 0.001) or intervertebral space height (P = 0.02), and lumbar mobility with thorax expansion (P = 0.004); DISH severity was correlated with basal (P = 0.04) and peak (P = 0.01) glucose levels after glucose load. In conclusion, chronic GH and IGF-I excess typically affects the axial skeleton with development of severe alterations of spine morphology and function until features of DISH occur. An early diagnosis of acromegaly is mandatory to reduce

  11. Spatial Analysis of Childhood Cancer: A Case/Control Study

    PubMed Central

    Ramis, Rebeca; Gómez-Barroso, Diana; Tamayo, Ibon; García-Pérez, Javier; Morales, Antonio; Pardo Romaguera, Elena; López-Abente, Gonzalo

    2015-01-01

    Background Childhood cancer was the leading cause of death among children aged 1-14 years for 2012 in Spain. Leukemia has the highest incidence, followed by tumors of the central nervous system (CNS) and lymphomas (Hodgkin lymphoma, HL, and Non-Hodgkin’s lymphoma, NHL). Spatial distribution of childhood cancer cases has been under concern with the aim of identifying potential risk factors. Objective The two objectives are to study overall spatial clustering and cluster detection of cases of the three main childhood cancer causes, looking to increase etiological knowledge. Methods We ran a case-control study. The cases were children aged 0 to 14 diagnosed with leukemia, lymphomas (HL and NHL) or CNS neoplasm in five Spanish regions for the period 1996-2011. As a control group, we used a sample from the Birth Registry matching every case by year of birth, autonomous region of residence and sex with six controls. We geocoded and validated the address of the cases and controls. For our two objectives we used two different methodologies. For the first, for overall spatial clustering detection, we used the differences of K functions from the spatial point patterns perspective proposed by Diggle and Chetwynd and the second, for cluster detection, we used the spatial scan statistic proposed by Kulldorff with a level for statistical significance of 0.05. Results We had 1062 cases of leukemia, 714 cases of CNS, 92 of HL and 246 of NHL. Accordingly we had 6 times the number of controls, 6372 controls for leukemia, 4284 controls for CNS, 552 controls for HL and 1476 controls for NHL. We found variations in the estimated empirical D(s) for the different regions and cancers, including some overall spatial clustering for specific regions and distances. We did not find statistically significant clusters. Conclusions The variations in the estimated empirical D(s) for the different regions and cancers could be partially explained by the differences in the spatial distribution of

  12. Haematopoietic cancer and medical history: a multicentre case control study

    PubMed Central

    Vineis, P.; Crosignani, P.; Sacerdote, C.; Fontana, A.; Masala, G.; Miligi, L.; Nanni, O.; Ramazzotti, V.; Rodella, S.; Stagnaro, E.; Tumino, R.; Vigano, C.; Vindigni, C.; Costantini, A. S.

    2000-01-01

    BACKGROUND—Viruses (such as Epstein-Barr virus) and pathological conditions (mainly involving immunosuppression) have been shown to increase the risk of haematolymphopoietic malignancies. Other associations (diabetes, tonsillectomy, autoimmune diseases) have been inconsistently reported.
METHODS—The association between different haematolymphopoietic malignancies (lymphomas, myelomas and leukaemias) and the previous medical history has been studied in a population-based case-control investigation conducted in Italy, based on face to face interviews to 2669 cases and 1718 population controls (refusal rates 10% and 19%, respectively). Controls were a random sample of the general population.
RESULTS—Previous findings were confirmed concerning the association between non-Hodgkin's lymphoma (NHL) and lupus erythematosus (odds ratio, OR=8.4; 95% CI 1.6, 45), tuberculosis (OR=1.6; 1.05, 2.5) and hepatitis (1.8; 1.4, 2.3). An association was found also between NHL and maternal (OR=2.8; 1.1, 6.9) or paternal tuberculosis (OR=1.7; 0.7, 3.9). Odds ratios of 4.0 (1.4, 11.8) and 4.4 (1.1, 6.6) were detected for the association between NHL and Hodgkin's disease, respectively, and previous infectious mononucleosis, but recall bias cannot be ruled out. No association was found with diabetes, tonsillectomy and adenoidectomy. An association with malaria at young age and "low grade" lymphatic malignancies is suggested. One interesting finding was the observation of four cases of poliomyelitis among NHL patients, one among Hodgkin's disease and one among myeloid leukaemia patients, compared with none among the controls (Fisher's exact test for NHL and Hodgkin's disease, p= 0.03, one tail).
CONCLUSIONS—Some of these findings are confirmatory of previous evidence. Other observations, such as the putative role of the polio virus and of malaria are new. A unifying theory on the mechanisms by which previous medical history may increase the risk of

  13. Biomass Fuel Smoke and Tuberculosis: A Case-Control Study.

    PubMed

    Haque, M A; Barman, N; Islam, M T; Mannan, M; Khan, M H; Karim, M R; Rob, M A; Hossain, M A

    2016-01-01

    This case control study was done to ascertain the association between exposures to biomass cooking fuel smoke and pulmonary tuberculosis. Cases were all newly diagnosed pulmonary tuberculosis patients, randomly collected from the Hospital (DOTS centers) Registry from January 2012 to June 2012 from two Upazillas of Sirajganj district, Bangladesh. A home visitation program was done subsequently. Healthy controls were recruited from the neighbourhood of each case through a predefined procedure. Total 276 new pulmonary tuberculosis cases and 276 neighbourhood controls were enrolled. A semi-structured questionnaire containing demographic information, smoking habits, cooking place, kitchen condition, use of biomass fuel for cooking was used for interview. Crude (unadjusted) odd ratios and their corresponding 95% confidence limits for independent variables were determined by binary logistic regression. All significant variables were entered into a multivariate conditional logistic regression model and a final fitted model was determined by backward elimination methods. In univariate analysis, member of a nuclear family {Unadjusted odd ratio (Unadj. OR) 1.570, 95% CI 1.008-2.44)}, having non-formal education (Unadj. OR 2.739, 95% CI 1.219, 6.153) or primary (Unadj. OR 3.407, 95% CI 1.492, 7.782) to secondary level (Unadj. OR 2.392, 95% CI 1.032, 5.544) education, using cow dung (Unadj. OR 3.961, 95% CI 1.267, 12.376) and biomass fuel i.e. plant origin (Unadj. OR 3.382, 95% CI 1.087, 10.518) for cooking, past smoker (Unadj. OR 2.504, 95% CI 1.061, 5.910), using open oven (Unadj. OR 3.109, 95% CI 0.995, 9.716), having small kitchen area (Unadj. OR 0.99, 95% CI 0.989, 0.999) all were significantly associated with tuberculosis. When all significant variables were entered into a multivariate conditional logistic regression model nuclear family {Adjusted odd ratio (Adj OR) 1.808, 95% CI 1.127, 2.9)}, primary level education (Adj OR 2.86, 95% CI 1.23, 6.647) and non formal

  14. Using cumulative sums of martingale residuals for model checking in nested case-control studies.

    PubMed

    Borgan, Ørnulf; Zhang, Ying

    2015-09-01

    Standard use of Cox regression requires collection of covariate information for all individuals in a cohort even when only a small fraction of them experiences the event of interest (fail). This may be very expensive for large cohorts. Further in biomarker studies, it will imply a waste of valuable biological material that one may want to save for future studies. A nested case-control study offers a useful alternative. For this design, covariate information is only needed for the failing individuals (cases) and a sample of controls selected from the cases' at-risk sets. Methods based on martingale residuals are useful for checking the fit of Cox's regression model for cohort data. But similar methods have so far not been developed for nested case-control data. In this article, it is described how one may define martingale residuals for nested case-control data, and it is shown how plots and tests based on cumulative sums of martingale residuals may be used to check model fit. The plots and tests may be obtained using available software.

  15. Case-control study of respiratory cancer and employment

    SciTech Connect

    Glazer, E.R.; Chiang, M.L.

    1984-04-01

    A multiple logistic risk-analysis procedure was used to compare data from 346 case/control pairs to determine occupational/industrial risk factors for respiratory cancer. The duration of employment was considered in blue-collar production occupations. Five industrial categories were included: shipyard, petrochemical, metal-related, construction and a grouping of other occupations under a single heading. The bulk of this grouped category was made up of blue collar employees in the industries of transportation, food production, wholesale and retail trade, professional services, and public administration. Specific attention was given to asbestos exposure, cigarette smoking, educational level attained, and dietary factors such as consumption of vegetables, fruits, and alcohol. A moderately elevated risk for respiratory cancer existed among employees in the metal industry and grouped categories when employment was over 30 years duration. In the metal industry this increase was almost entirely due to a larger than expected number of cases of larynx cancer.

  16. Valid statistical inference methods for a case-control study with missing data.

    PubMed

    Tian, Guo-Liang; Zhang, Chi; Jiang, Xuejun

    2016-05-19

    The main objective of this paper is to derive the valid sampling distribution of the observed counts in a case-control study with missing data under the assumption of missing at random by employing the conditional sampling method and the mechanism augmentation method. The proposed sampling distribution, called the case-control sampling distribution, can be used to calculate the standard errors of the maximum likelihood estimates of parameters via the Fisher information matrix and to generate independent samples for constructing small-sample bootstrap confidence intervals. Theoretical comparisons of the new case-control sampling distribution with two existing sampling distributions exhibit a large difference. Simulations are conducted to investigate the influence of the three different sampling distributions on statistical inferences. One finding is that the conclusion by the Wald test for testing independency under the two existing sampling distributions could be completely different (even contradictory) from the Wald test for testing the equality of the success probabilities in control/case groups under the proposed distribution. A real cervical cancer data set is used to illustrate the proposed statistical methods.

  17. Lung cancer risk among bricklayers in a pooled analysis of case-control studies.

    PubMed

    Consonni, Dario; De Matteis, Sara; Pesatori, Angela C; Bertazzi, Pier Alberto; Olsson, Ann C; Kromhout, Hans; Peters, Susan; Vermeulen, Roel C H; Pesch, Beate; Brüning, Thomas; Kendzia, Benjamin; Behrens, Thomas; Stücker, Isabelle; Guida, Florence; Wichmann, Heinz-Erich; Brüske, Irene; Landi, Maria Teresa; Caporaso, Neil E; Gustavsson, Per; Plato, Nils; Tse, Lap Ah; Yu, Ignatius Tak-Sun; Jöckel, Karl-Heinz; Ahrens, Wolfgang; Pohlabeln, Hermann; Merletti, Franco; Richiardi, Lorenzo; Simonato, Lorenzo; Forastiere, Francesco; Siemiatycki, Jack; Parent, Marie-Élise; Tardón, Adonina; Boffetta, Paolo; Zaridze, David; Chen, Ying; Field, John K; 't Mannetje, Andrea; Pearce, Neil; McLaughlin, John; Demers, Paul; Lissowska, Jolanta; Szeszenia-Dabrowska, Neonila; Bencko, Vladimir; Foretova, Lenka; Janout, Vladimir; Rudnai, Peter; Fabiánová, Eleonóra; Stanescu Dumitru, Rodica; Bueno-de-Mesquita, H Bas; Schüz, Joachim; Straif, Kurt

    2015-01-15

    Bricklayers may be exposed to several lung carcinogens, including crystalline silica and asbestos. Previous studies that analyzed lung cancer risk among these workers had several study design limitations. We examined lung cancer risk among bricklayers within SYNERGY, a large international pooled analysis of case-control studies on lung cancer and the joint effects of occupational carcinogens. For men ever employed as bricklayers we estimated odds ratios (OR) and 95% confidence intervals (CI) adjusted for study center, age, lifetime smoking history and employment in occupations with exposures to known or suspected lung carcinogens. Among 15,608 cases and 18,531 controls, there were 695 cases and 469 controls who had ever worked as bricklayers (OR: 1.47; 95% CI: 1.28-1.68). In studies using population controls the OR was 1.55 (95% CI: 1.32-1.81, 540/349 cases/controls), while it was 1.24 (95% CI: 0.93-1.64, 155/120 cases/controls) in hospital-based studies. There was a clear positive trend with length of employment (p < 0.001). The relative risk was higher for squamous (OR: 1.68, 95% CI: 1.42-1.98, 309 cases) and small cell carcinomas (OR: 1.78, 95% CI: 1.44-2.20, 140 cases), than for adenocarcinoma (OR: 1.17, 95% CI: 0.95-1.43, 150 cases) (p-homogeneity: 0.0007). ORs were still elevated after additional adjustment for education and in analyses using blue collar workers as referents. This study provided robust evidence of increased lung cancer risk in bricklayers. Although non-causal explanations cannot be completely ruled out, the association is plausible in view of the potential for exposure to several carcinogens, notably crystalline silica and to a lesser extent asbestos.

  18. Multiple myeloma--a case-control study.

    PubMed Central

    Cuzick, J.; De Stavola, B.

    1988-01-01

    A total of 399 patients with multiple myeloma and an equal number of match controls were interviewed about factors possibly related to the causes of their disease. Factors studied included occupation, chemical exposure, radiation exposure, prior diseases, immunizations, chronic infections and markers for defects in immune regulation. A strong risk associated with agriculture/food processing was observed (RR = 1.8, P = 0.002). The risk could not be restricted to those exposed to animals or meat products, or those exposed to pesticides. Significant excesses were also noted for reported exposures to chemicals and gases/fumes, but no specific agent or group of agents could be identified. Cases had fewer tonsillectomies above the age of 10 (P = 0.01). A large excess of shingles (herpes zoster) was observed in cases (P less than 0.001), but most of the excess cases occurred within 10 years of diagnosis, suggesting this was a preclinical manifestation of disease rather than a cause of it. PMID:3395559

  19. Parental smoking and childhood asthma: longitudinal and case-control studies

    PubMed Central

    Strachan, D.; Cook, D.

    1998-01-01

    BACKGROUND—The relation of parental smoking to wheezing and asthma occurring after the first year of life was assessed by a systematic quantitative review of case-control and longitudinal studies, complementing earlier reviews of cross sectional surveys and wheezing in early childhood.
METHODS—Fifty one relevant publications were identified after consideration of 1593 abstracts selected by electronic search of the Embase and Medline databases using keywords relevant to passive smoking in children. The search was completed in April 1997 and identified six studies of asthma incidence, seven of prognosis, 22 case-control studies, and 10 case series addressing disease severity.
RESULTS—Maternal smoking was associated with an increased incidence of wheezing illness up to age 6 (pooled odds ratio 1.31, 95% CI 1.22 to 1.41), but less strongly thereafter (1.13, 95% CI 1.04to 1.22). The long term prognosis of early wheezing illness was better if the mother smoked. The pooled odds ratio for asthma prevalence from 14 case-control studies was 1.37 (95% CI 1.15to 1.64) if either parent smoked. Four studies suggest that parental smoking is more strongly associated with wheezing among non-atopic children. Indicators of disease severity including symptom scores, attack frequency, medication use, hospital attendance, and life threatening bronchospasm were in general positively related to household smoke exposure.
CONCLUSIONS—The excess incidence of wheezing in smoking households appears to be largely non-atopic "wheezy bronchitis" with a relatively benign prognosis, but among children with established asthma, parental smoking is associated with more severe disease. This apparent paradox may be reconciled if environmental tobacco smoke is considered a co-factor provoking wheezing attacks, rather than a cause of the underlying asthmatic tendency.

 PMID:9659358

  20. Bayesian sample size determination for case-control studies when exposure may be misclassified.

    PubMed

    Joseph, Lawrence; Bélisle, Patrick

    2013-12-01

    Odds ratios are frequently used for estimating the effect of an exposure on the probability of disease in case-control studies. In planning such studies, methods for sample size determination are required to ensure sufficient accuracy in estimating odds ratios once the data are collected. Often, the exposure used in epidemiologic studies is not perfectly ascertained. This can arise from recall bias, the use of a proxy exposure measurement, uncertain work exposure history, and laboratory or other errors. The resulting misclassification can have large impacts on the accuracy and precision of estimators, and specialized estimation techniques have been developed to adjust for these biases. However, much less work has been done to account for the anticipated decrease in the precision of estimators at the design stage. Here, we develop methods for sample size determination for odds ratios in the presence of exposure misclassification by using several interval-based Bayesian criteria. By using a series of prototypical examples, we compare sample size requirements after adjustment for misclassification with those required when this problem is ignored. We illustrate the methods by planning a case-control study of the effect of late introduction of peanut to the diet of children to the subsequent development of peanut allergy.

  1. A low-level asbestos exposure case-control epidemiology study

    SciTech Connect

    Ocasio-Alvarex, A.

    1988-01-01

    The potential for low levels of airborne asbestos exposure in public schools and in public and commercial buildings in the United States has generated concern due to the large population at risk and the definite human carcinogenicity of asbestos at high levels. To assist in the clarification of the risk associated with low level asbestos exposure and in the decision-making in asbestos management in schools and in other buildings, a case-control study was conducted to estimate the risk relationship between low levels of asbestos exposure and pulmonary cancer among Indiana public school teachers. A total of 236 lung cancer cases and 154 controls to be used in this case-control study were identified from a previous proportionate mortality rate study which had examined over 8,000 teachers' death certificates. The controls were selected from teachers who died of chronic bronchitis, emphysema or a chronic obstructive pulmonary disease. The teachers' work history and their potential for asbestos exposure, as well as the reliability of the information obtained on the presence or absence of asbestos, was determined to calculate the odds ratio.

  2. Tularemia Outbreak Investigation in Kosovo: Case Control and Environmental Studies

    PubMed Central

    Dedushaj, Isuf; Gjini, Ardiana; Jorgensen, Tine Rikke; Cotter, Benvon; Lieftucht, Alfons; D’Ancona, Fortunato; Dennis, David T.; Kosoy, Michael A.; Mulliqi-Osmani, Gjyle; Grunow, Roland; Kalaveshi, Ariana; Gashi, Luljeta; Humolli, Isme

    2002-01-01

    A large outbreak of tularemia occurred in Kosovo in the early postwar period, 1999-2000. Epidemiologic and environmental investigations were conducted to identify sources of infection, modes of transmission, and household risk factors. Case and control status was verified by enzyme-linked immunosorbent assay, Western blot, and microagglutination assay. A total of 327 serologically confirmed cases of tularemia pharyngitis and cervical lymphadenitis were identified in 21 of 29 Kosovo municipalities. Matched analysis of 46 case households and 76 control households suggested that infection was transmitted through contaminated food or water and that the source of infection was rodents. Environmental circumstances in war-torn Kosovo led to epizootic rodent tularemia and its spread to resettled rural populations living under circumstances of substandard housing, hygiene, and sanitation. PMID:11749751

  3. A case-control study of Nocardia mastitis in Nova Scotia dairy herds

    PubMed Central

    Ferns, Lyn; Dohoo, Ian; Donald, Alan

    1991-01-01

    A case-control study was conducted to identify herd production, housing, and hygienic and therapeutic factors associated with a diagnosis of Nocardia mastitis in dairy herds in Nova Scotia. The data were collected by on-farm interviews with owners of 54 case and 54 control herds. Logistic regression was used to study risk factors. The use of dry cow products containing neomycin, including two specific dry cow products, was strongly associated with a diagnosis of Nocardia mastitis in a herd. Other factors which increased the risk of Nocardia mastitis were higher levels of production, larger herd size, and a large percentage of cows treated with dry cow products. These results are compared to results from a similar study carried out in Ontario. PMID:17423896

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

    PubMed

    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.

  5. Nonoliguric hyperkalemia in neonates: a case-controlled study.

    PubMed

    Yaseen, Hakam

    2009-03-01

    The objective of this study was to determine the incidence, risk factors, and morbidities associated with nonoliguric hyperkalemia (NOHK) in neonates. Infants were eligible for the study if they were born at Al Qassimi Hospital and fulfilled the diagnostic criteria of NOHK (serum potassium [SK] > or = 7 mmol/L during the first 72 hours of life with urinary output > or = 1 mL/kg/h). The next admitted infant with gestational age +/- 1 week and normal SK acted as control. Exclusion criteria were severe congenital malformation, renal failure, failure of adequate urinary collection, and early blood transfusion within the first 72 hours of life. Fluid intake and urinary output were monitored. Infants who developed hyperkalemia (SK > or = 6.5 mmol/L in two nonhemolysed venous or arterial blood samples) had serum potassium measured every 4 hours until it reached below 6 mmol/L. Hyperkalemia was identified between 6 and 36 hours of age in 45 infants (peak SK 7 to 9.3 mmol/L). During the time of the study, the prevalence of NOHK was 24% among extremely-low-birth-weight infants (with birth weight < 1000 g) who comprised 83% of those identified. Of infants with NOHK, 13% developed tachycardiac arrhythmia and 17% died. NOHK was significantly associated with fetal distress, early metabolic acidosis, early hyperglycemia, and absence of antenatal steroid administration. Hyperkalemic infants had significantly lower serum calcium and higher serum phosphorous, urea, and creatinine. Early polyuric episodes and high urinary output were also more common in hyperkalemic infants. NOHK affects mainly preterm infants. Electrolyte disturbance and increased serum urea and creatinine were associated with hyperkalemia. Infants with NOHK also had high incidence of cardiac arrhythmias and mortality.

  6. Vertebral hyperostosis and diabetes mellitus: a case-control study.

    PubMed Central

    Daragon, A; Mejjad, O; Czernichow, P; Louvel, J P; Vittecoq, O; Durr, A; Le Loët, X

    1995-01-01

    OBJECTIVE--To compare glucose metabolism in patients with vertebral hyperostosis (VH), with that in control patients. METHODS--We studied 50 patients aged 60 years or more who had VH according to Resnick's criteria, and 50 control patients without VH, matched for sex, age, weight and height. Plasma glucose was evaluated before and 120 minutes after ingestion of 75 g glucose. World Health Organisation criteria for diabetes mellitus (DM) were used. Radiographs of the pelvis and thoracic and lumbar spine were performed and read blind by two physicians. RESULTS--Statistical analysis showed no difference between cases and control patients for prevalence of DM, and plasma glucose at 0 and 120 minutes. CONCLUSION--These data suggest that glucoregulation in patients with VH does not differ from that in matched controls. PMID:7794043

  7. Study design in evidence-based surgery: What is the role of case-control studies?

    PubMed Central

    Cao, Amy M; Cox, Michael R; Eslick, Guy D

    2016-01-01

    Randomized controlled trials (RCTs) are the gold standard in terms of study design, however, in the surgical setting conducting RCTs can often be unethical or logistically impossible. Case-control studies should become the major study design used in surgical research when RCTs are unable to be conducted and definitely replacing case series which offer little insight into surgical outcomes and disease processes. PMID:27019801

  8. Trachoma and Relative Poverty: A Case-Control Study

    PubMed Central

    Habtamu, Esmael; Wondie, Tariku; Aweke, Sintayehu; Tadesse, Zerihun; Zerihun, Mulat; Zewdie, Zebideru; Callahan, Kelly; Emerson, Paul M.; Kuper, Hannah; Bailey, Robin L.; Mabey, David C. W.; Rajak, Saul N.; Polack, Sarah; Weiss, Helen A.; Burton, Matthew J.

    2015-01-01

    Background Trachoma is widely considered a disease of poverty. Although there are many epidemiological studies linking trachoma to factors normally associated with poverty, formal quantitative data linking trachoma to household economic poverty within endemic communities is very limited. Methodology/Principal Findings Two hundred people with trachomatous trichiasis were recruited through community-based screening in Amhara Region, Ethiopia. These were individually matched by age and gender to 200 controls without trichiasis, selected randomly from the same sub-village as the case. Household economic poverty was measured through (a) A broad set of asset-based wealth indicators and relative household economic poverty determined by principal component analysis (PCA, (b) Self-rated wealth, and (c) Peer-rated wealth. Activity participation data were collected using a modified ‘Stylised Activity List’ developed for the World Bank’s Living Standards Measurement Survey. Trichiasis cases were more likely to belong to poorer households by all measures: asset-based analysis (OR = 2.79; 95%CI: 2.06–3.78; p<0.0001), self-rated wealth (OR, 4.41, 95%CI, 2.75–7.07; p<0.0001) and peer-rated wealth (OR, 8.22, 95% CI, 4.59–14.72; p<0.0001). Cases had less access to latrines (57% v 76.5%, p = <0.0001) and higher person-to-room density (4.0 v 3.31; P = 0.0204) than the controls. Compared to controls, cases were significantly less likely to participate in economically productive activities regardless of visual impairment and other health problems, more likely to report difficulty in performing activities and more likely to receive assistance in performing productive activities. Conclusions/Significance This study demonstrated a strong association between trachomatous trichiasis and relative poverty, suggesting a bidirectional causative relationship possibly may exist between poverty and trachoma. Implementation of the full SAFE strategy in the context of general improvements

  9. Case-control study of amyotrophic lateral sclerosis

    SciTech Connect

    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.

  10. Dropped head syndrome after cervical laminoplasty: A case control study.

    PubMed

    Koda, Masao; Furuya, Takeo; Kinoshita, Tomoaki; Miyashita, Tomohiro; Ota, Mitsutoshi; Maki, Satoshi; Ijima, Yasushi; Saito, Junya; Takahashi, Kazuhisa; Yamazaki, Masashi; Aramomi, Masaaki; Mannoji, Chikato

    2016-10-01

    Dropped head syndrome (DHS) is characterized by apparent neck extensor muscle weakness and difficulty extending the neck to raise the head against gravity. The aim of the present study was to elucidate possible risk factors for DHS after cervical laminoplasty. Five patients who developed DHS after cervical laminoplasty (DHS group) and twenty age-matched patients who underwent laminoplasty without DHS after surgery (control group) were compared. The surgical procedure was single-door laminoplasty with strut grafting using resected spinous processes or hydroxyapatite spacers from C3 to C6 or C7. Analyses of preoperative images including the C2-C7 angle, C7-T1 kyphosis, T1 tilt, center of gravity line from the head-C7 sagittal vertical axis (CGH-C7 SVA) were performed on lateral plain cervical spine radiographs. Preoperative T2-weighted MRI at the C5 vertebral level was used to measure the cross-sectional area of the deep extensor muscles. Widths of the lateral gutters were assessed postoperatively using CT scans of the C5 vertebral body. The average preoperative C2-C7 angle was significantly smaller in the DHS group compared with the control group. The average preoperative C7-T1 angle was significantly larger in the DHS group compared with the control group. The average preoperative CGH-C7 SVA was significantly larger in the DHS group compared with the control group. In conclusion, patients with more pronounced preoperative C2-C7 kyphosis, C7-T1 kyphosis, and CGH-C7 SVA are more likely to develop DHS following laminoplasty.

  11. Risk factors in highway traffic accidents: a case control study.

    PubMed

    Hijar, M; Carrillo, C; Flores, M; Anaya, R; Lopez, V

    2000-09-01

    The objective of this study was to identify risk factors related to the driver, the vehicle and the environment, that are associated with motor vehicles accidents on highways. A case and control design was used where the case was: the driver of a motor vehicle who was involved in an accident while traveling on the Mexico-Cuernavaca highway; and the control was: the driver or a motor vehicle who, traveling on the highway, completed the trip without being involved in a traffic accident. Risk factors associated with the occurrence of a traffic accident (P > 0.05) were: age under 25 years, frequent travel, traveling to work, alcohol consumption, driving during the daylight, on a week-day, under adverse weather conditions and in the Mexico Cuernavaca direction of road. Risks adjusted by logistic regression were: age under 25 years odds ratio (OR) 3.01, confidence interval (CI) (95%) 1.46-6.18; work as a travel reason OR 1.74, CI 1.06 2.86; alcohol intake OR 4.70, Cl 1.62 13.6; driving under adverse weather conditions OR 5.70, CI 3.66-8.85; traveling on a week-day OR 1.84, CI 1.14-2.94; during daylight hours OR 4.23, CI 2.36-7.58 and in the Mexico Cuernavaca direction of road OR 2.69, CI 1.67 4.32. The identification of factors associated with the risk of being involved in a highway traffic accident allows us to propose primary prevention measures for this important public health problem.

  12. Primary biliary cirrhosis and osteoporosis: a case-control study.

    PubMed

    Mounach, Aziza; Ouzzif, Zhor; Wariaghli, Ghizlane; Achemlal, Lahsen; Benbaghdadi, Imane; Aouragh, Aziz; Bezza, Ahmed; El Maghraoui, Abdellah

    2008-01-01

    Osteoporosis is a common complication of chronic liver disease, from cholestatic disorders to autoimmune, alcoholic, and posthepatitic cirrhosis. Osteoporosis appears more striking in patients with primary biliary cirrhosis (PBC) because the disease usually affects elderly women, who are naturally prone to osteoporosis. Our aims were (1) to compare the prevalence of osteoporosis (T-score <-2.5 SD) between PBC patients and a group of age-and sex-matched controls consisting of healthy subjects from the general population; and (2) to identify the main risk factors for the development of bone loss. Thirty-three women with PBC (mean age, 47.3 +/- 10.4 years) and 66 healthy subjects were enrolled in the study. Bone mineral density (BMD) was assessed at the lumbar spine by dual-photon X-ray absorptiometry. Bone metabolism was evaluated by measuring serum calcium corrected for serum albumin, 25-hydroxyvitamin D (25-OH vit D), parathyroid hormone, and osteocalcin. Vertebral fractures were analyzed using vertebral fracture assessment (VFA). The mean T-score was lower in the PBC group compared to healthy controls, with a significant statistical difference (-2.39 +/- 0.93 and -1.47 +/- 0.99 in lumbar spine and total hip, respectively, in the PBC group versus -0.99 +/- 0.51 and -0.56 +/- 1.14 in healthy controls (P < 0.001). The prevalence of osteoporosis was 51.5% in the PBC group versus 22.7% in healthy controls with a statistically significant difference (P = 0.004). BMD of the PBC group was significantly correlated positively with body mass index (BMI) and 25-OH vit D, and negatively with menopausal status, duration of disease, and parathyroid hormone (PTH) levels. Vertebral fractures were present in 9% of the patients. We found that osteoporosis is more prevalent in women with PBC than in the general population. BMI, menopausal status, duration of the disease, and vitamin D deficiency are the main risk factors for osteoporosis in this liver disease.

  13. Congenital anosmia and emotion recognition: A case-control study.

    PubMed

    Lemogne, Cédric; Smadja, Julien; Zerdazi, El-Hadi; Soudry, Yaël; Robin, Marion; Berthoz, Sylvie; Limosin, Frédéric; Consoli, Silla M; Bonfils, Pierre

    2015-06-01

    Patients with anosmia are not able to detect volatile chemicals signaling the presence of infectious and non-infectious environmental hazards, which typically elicit disgust and fear, respectively. Social animals may compensate a loss of olfaction by taking advantage of signals of threat that are produced by their conspecifics. Among humans and other primates, body postures and facial expressions are powerful cues conveying emotional information, including fear and disgust. The aim of the present study was to examine whether humans with agenesis of the olfactory bulb, a rare disorder characterized by congenital anosmia, would be more accurate in recognizing facial expressions of fear and disgust. A total of 90 participants with no history of mental disorder or traumatic brain injury were recruited, including 17 patients with congenital anosmia (10 men, mean age ± standard deviation: 36.5 ± 14.8 years), 34 patients with acquired anosmia (18 men, mean age ± standard deviation: 57.2 ± 11.8 years) and 39 healthy subjects (22 men, mean age ± standard deviation: 36.7 ± 13.2 years). For each patient with congenital anosmia, the agenesis of the olfactory bulb was ascertained through magnetic resonance imaging. Emotion recognition abilities were examined with a dynamic paradigm in which a morphing technique allowed displaying emotional facial expressions increasing in intensity over time. Adjusting for age, education, depression and anxiety, patients with congenital anosmia required similar levels of intensity to correctly recognize fear and disgust than healthy subjects while they displayed decreased error rates for both fear (mean difference [95% confidence interval] = -28.3% [-46.3%, -10.2%], P = 0.003) and disgust (mean difference [95% confidence interval] = -15.8% [-31.5%, -0.2%], P = 0.048). Furthermore, among patients with acquired anosmia, there was a negative correlation between duration of anosmia and the rate of errors for fearful (Spearman's ρ = -0.531, P

  14. 77 FR 12598 - Notice Correction; A Multi-Center International Hospital-Based Case-Control Study of Lymphoma in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-01

    ...-Based Case-Control Study of Lymphoma in Asia (AsiaLymph) (NCI) The Federal Register notice published on... international hospital-based case-control study of lymphoma in Asia (AsiaLymph) (NCI)'' was submitted with...

  15. Risk factors in lateral epicondylitis (tennis elbow): a case-control study.

    PubMed

    Titchener, A G; Fakis, A; Tambe, A A; Smith, C; Hubbard, R B; Clark, D I

    2013-02-01

    Lateral epicondylitis is a common condition, but relatively little is known about its aetiology and associated risk factors. We have undertaken a large case-control study using The Health Improvement Network database to assess and quantify the relative contributions of some constitutional and environmental risk factors for lateral epicondylitis in the community. Our dataset included 4998 patients with lateral epicondylitis who were individually matched with a single control by age, sex, and general practice. The median age at diagnosis was 49 (interquartile range 42-56) years . Multivariate analysis showed that the risk factors associated with lateral epicondylitis were rotator cuff pathology (OR 4.95), De Quervain's disease (OR 2.48), carpal tunnel syndrome (OR 1.50), oral corticosteroid therapy (OR 1.68), and previous smoking history (OR 1.20). Diabetes mellitus, current smoking, trigger finger, rheumatoid arthritis, alcohol intake, and obesity were not found to be associated with lateral epicondylitis.

  16. Two-stage replication of previous genome-wide association studies of AS3MT-CNNM2-NT5C2 gene cluster region in a large schizophrenia case-control sample from Han Chinese population.

    PubMed

    Guan, Fanglin; Zhang, Tianxiao; Li, Lu; Fu, Dongke; Lin, Huali; Chen, Gang; Chen, Teng

    2016-10-01

    Schizophrenia is a devastating psychiatric condition with high heritability. Replicating the specific genetic variants that increase susceptibility to schizophrenia in different populations is critical to better understand schizophrenia. CNNM2 and NT5C2 are genes recently identified as susceptibility genes for schizophrenia in Europeans, but the exact mechanism by which these genes confer risk for schizophrenia remains unknown. In this study, we examined the potential for genetic susceptibility to schizophrenia of a three-gene cluster region, AS3MT-CNNM2-NT5C2. We implemented a two-stage strategy to conduct association analyses of the targeted regions with schizophrenia. A total of 8218 individuals were recruited, and 45 pre-selected single nucleotide polymorphisms (SNPs) were genotyped. Both single-marker and haplotype-based analyses were conducted in addition to imputation analysis to increase the coverage of our genetic markers. Two SNPs, rs11191419 (OR=1.24, P=7.28×10(-5)) and rs11191514 (OR=1.24, P=0.0003), with significant independent effects were identified. These results were supported by the data from both the discovery and validation stages. Further haplotype and imputation analyses also validated these results, and bioinformatics analyses indicated that CALHM1, which is located approximately 630kb away from CNNM2, might be a susceptible gene for schizophrenia. Our results provide further support that AS3MT, CNNM2 and CALHM1 are involved with the etiology and pathogenesis of schizophrenia, suggesting these genes are potential targets of interest for the improvement of disease management and the development of novel pharmacological strategies.

  17. Coffee consumption and risk of colorectal cancer: a meta-analysis of case-control studies.

    PubMed

    Galeone, Carlotta; Turati, Federica; La Vecchia, Carlo; Tavani, Alessandra

    2010-11-01

    A meta-analysis of case-control studies on coffee consumption and colorectal cancer risk was conducted. Twenty-four eligible studies published before May 2010 were identified, including a total of 14,846 cases of colorectal, colon or rectal cancer. Compared to non/occasional drinkers, the odds ratios (OR) for drinkers were 0.83 (95% CI 0.73-0.95) for colorectal, 0.93 (95% CI 0.81-1.07) for colon and 0.98 (95% CI 0.85-1.13) for rectal cancer, with significant heterogeneity among studies; the corresponding ORs for the increment of 1 cup/day were 0.94 (95% CI 0.91-0.98), 0.95 (95% CI 0.92-0.98), and 0.97 (95% CI 0.95-0.99). For the highest coffee drinkers, the ORs were 0.70 (95% CI 0.60-0.81) for colorectal cancer, 0.75 (95% CI 0.64-0.88) for colon cancer and 0.87 (95% CI 0.75-1.00) for rectal cancer, when compared to non/low drinkers. The results of this meta-analysis of case-control studies suggest a moderate favorable effect of coffee consumption on colorectal cancer risk. The reduced risk was consistent across study design (hospital vs. population based), geographic area, and various confounding factors considered. It may reflect a real protection but also partly or largely be due to reverse causation, i.e. decreased coffee consumption among cases following the onset of bowel symptoms.

  18. Selective Serotonin Reuptake Inhibitors and Gastrointestinal Bleeding: A Case-Control Study

    PubMed Central

    Carvajal, Alfonso; Ortega, Sara; Del Olmo, Lourdes; Vidal, Xavier; Aguirre, Carmelo; Ruiz, Borja; Conforti, Anita; Leone, Roberto; López-Vázquez, Paula; Figueiras, Adolfo; Ibáñez, Luisa

    2011-01-01

    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. PMID:21625637

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

    PubMed Central

    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

  20. General practitioner notes as a source of information for case-control studies in young women. UK National Case-Control Study Group.

    PubMed Central

    Chilvers, C E; Pike, M C; Taylor, C N; Hermon, C; Crossley, B; Smith, S J

    1994-01-01

    STUDY OBJECTIVE--The UK National Case-Control Study was carried out to investigate the relationship between oral contraceptive use and breast cancer risk. This study investigates whether general practitioner notes could be used as the sole data source for epidemiological studies of young women and what the effect would be on non-response and recall bias. DESIGN--Case-control study with data on gynaecological, obstetric, and contraceptive history collected at interview and from general practitioners' notes. Information from these two sources was compared. SETTING--This was a population-based study. PARTICIPANTS--Altogether 755 women with breast cancer aged under 36 years at diagnosis, each with an age-matched control, participated in the study. Response rates at interview were 72% and 89% for cases and controls but GP data were available for 90% of the 1049 case and first-selected control pairs. MAIN RESULTS--There was generally good agreement between the two data sources with respect to obstetric history and gynaecological procedures (hysterectomy, oophorectomy, and tubal ligation). The use of intra-uterine devices, or diaphragm, and partner's vasectomy were not reliably recorded in the GP's notes. The overall results of the UK study would have been qualitatively the same with respect to the relationship between oral contraceptive use and breast cancer risk if GP notes only had been used, in spite of the fact that only about half of all oral contraceptive usage was recorded in the notes. Response rates would have been higher, recall bias eliminated, and the cost of the study halved. CONCLUSIONS--When planning case-control studies in young women, the possibility of using GP notes as the primary data source should be considered. Lack of data on potential confounding factors is a possible drawback to such use. The practice of destroying GP's notes shortly after the death of patients seriously restricts the possibility of using these notes when studying rapidly fatal

  1. A concordance index for matched case-control studies with applications in cancer risk.

    PubMed

    Brentnall, Adam R; Cuzick, Jack; Field, John; Duffy, Stephen W

    2015-02-10

    In unmatched case-control studies, the area under the receiver operating characteristic (ROC) curve (AUC) may be used to measure how well a variable discriminates between cases and controls. The AUC is sometimes used in matched case-control studies by ignoring matching, but it lacks interpretation because it is not based on an estimate of the ROC for the population of interest. We introduce an alternative measure of discrimination that is the concordance of risk factors conditional on the matching factors. Parametric and non-parametric estimators are given for different matching scenarios, and applied to real data from breast and lung cancer case-control studies. Diagnostic plots to verify the constancy of discrimination over matching factors are demonstrated. The proposed simple measure is easy to use, interpret, more efficient than unmatched AUC statistics and may be applied to compare the conditional discrimination performance of risk factors.

  2. Helicobacter pylori infection and early onset myocardial infarction: case-control and sibling pairs study

    PubMed Central

    Danesh, John; Youngman, Linda; Clark, Sarah; Parish, Sarah; Peto, Richard; Collins, Rory

    1999-01-01

    Objectives To examine the association between coronary heart disease and chronic Helicobacter pylori infection. Design Case-control study of myocardial infarction at young ages and study of sibling pairs with one member affected and the other not. Setting United Kingdom. Participants 1122 survivors of suspected acute myocardial infarction at ages 30-49 (mean age 44 years) and 1122 age and sex matched controls with no history of coronary heart disease; 510 age and sex matched pairs of siblings (mean age 59 years) in which one sibling had survived myocardial infarction and one had no history of coronary heart disease. Main outcome measures Serological evidence of chronic infection with H pylori. Results 472 (42%) of the 1122 cases with early onset myocardial infarction were seropositive for H pylori antibodies compared with 272 (24%) of the 1122 age and sex matched controls, giving an odds ratio of 2.28 (99% confidence interval 1.80 to 2.90). This odds ratio fell to 1.87 (1.42 to 2.47; P<0.0001) after smoking and indicators of socioeconomic status were adjusted for and to 1.75 (1.29 to 2.36) after additional adjustment for blood lipid concentrations and obesity. Only 158 of the 510 pairs of siblings were discordant for H pylori status; among these, 91 cases and 67 controls were seropositive (odds ratio 1.33 (0.86 to 2.05)). No strong correlations were observed between H pylori seropositivity and measurements of other risk factors for coronary heart disease (plasma lipids, fibrinogen, C reactive protein, albumin, etc). Conclusion In the context of results from other relevant studies, these two studies suggest a moderate association between coronary heart disease and H pylori seropositivity that cannot be fully accounted for by other risk factors. But even if this association is causal and largely reversible by eradication of chronic infection, very large randomised trials would be needed to show this. Key messagesMost previous studies of associations between chronic H

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

    ERIC Educational Resources Information Center

    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…

  4. National Case-Control Study of Homicide Offending and Methamphetamine Use

    ERIC Educational Resources Information Center

    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…

  5. Behavioural Comorbidity in Tanzanian Children with Epilepsy: A Community-Based Case-Control Study

    ERIC Educational Resources Information Center

    Burton, Kathryn; Rogathe, Jane; Hunter, Ewan; Burton, Matthew; Swai, Mark; Todd, Jim; Neville, Brian; Walker, Richard; Newton, Charles

    2011-01-01

    Aim: The aim of this study was to define the prevalence of and risk factors for behavioural disorders in children with epilepsy from a rural district of Tanzania by conducting a community-based case-control study. Method: One hundred and twelve children aged 6 to 14 years (55 males, 57 females; median age 12y) with active epilepsy (at least two…

  6. Case-Control Genome-Wide Association Study of Attention-Deficit/Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Neale, Benjamin M.; Medland, Sarah; Ripke, Stephan; Anney, Richard J. L.; Asherson, Philip; Buitelaar, Jan; Franke, Barbara; Gill, Michael; Kent, Lindsey; Holmans, Peter; Middleton, Frank; Thapar, Anita; Lesch, Klaus-Peter; Faraone, Stephen V.; Daly, Mark; Nguyen, Thuy Trang; Schafer, Helmut; Steinhausen, Hans-Christoph; Reif, Andreas; Renner, Tobias J.; Romanos, Marcel; Romanos, Jasmin; Warnke, Andreas; Walitza, Susanne; Freitag, Christine; Meyer, Jobst; Palmason, Haukur; Rothenberger, Aribert; Hawi, Ziarih; Sergeant, Joseph; Roeyers, Herbert; Mick, Eric; Biederman, Joseph

    2010-01-01

    Objective: Although twin and family studies have shown attention-deficit/hyperactivity disorder (ADHD) to be highly heritable, genetic variants influencing the trait at a genome-wide significant level have yet to be identified. Thus additional genome-wide association studies (GWAS) are needed. Method: We used case-control analyses of 896 cases…

  7. Alcohol consumption and psoriatic risk: a meta-analysis of case-control studies.

    PubMed

    Zhu, Kun-Ju; Zhu, Cheng-Yao; Fan, Yi-Ming

    2012-09-01

    Psoriasis is one of the most common dermatological disorders. The association between alcohol consumption and psoriasis has been inconsistent among studies. To examine the magnitude of the risk of developing psoriasis for drinking populations compared to those with non-drinking, and to determine causes of the variation in odds ratios (OR) between various case-control studies, we performed a comprehensive published work search and a meta-analysis of case-control studies considering prevalence. We did electronic searches on Medline, and searched reports to identify case-control studies of prevalent of psoriasis. We did meta-analyses of study-specific incremental estimates to determine the risk of psoriasis associated with drinking. The magnitude of the OR was analyzed by combining 15 case-control studies that matched defined criteria. The variance in OR between studies was explored. The overall OR of psoriasis for drinking persons compared to those with non-drinking was 1.531 (95% confidence interval [CI] = 1.164-2.014, P = 0.002) and the association remains statistically significant across a number of stratified analyses in European descent subgroup (OR = 1.432, 95% CI = 1.085-1.889, P = 0.011) and also persists in sensitivity analyses performed to assess the potential effect of varying psoriasis outcome definitions. Alcohol consumption is associated with increased risk of psoriasis. These epidemiological observations should inform the exploration of biological mechanisms that link alcohol consumption with psoriasis.

  8. Using full-cohort data in nested case-control and case-cohort studies by multiple imputation.

    PubMed

    Keogh, Ruth H; White, Ian R

    2013-10-15

    In many large prospective cohorts, expensive exposure measurements cannot be obtained for all individuals. Exposure-disease association studies are therefore often based on nested case-control or case-cohort studies in which complete information is obtained only for sampled individuals. However, in the full cohort, there may be a large amount of information on cheaply available covariates and possibly a surrogate of the main exposure(s), which typically goes unused. We view the nested case-control or case-cohort study plus the remainder of the cohort as a full-cohort study with missing data. Hence, we propose using multiple imputation (MI) to utilise information in the full cohort when data from the sub-studies are analysed. We use the fully observed data to fit the imputation models. We consider using approximate imputation models and also using rejection sampling to draw imputed values from the true distribution of the missing values given the observed data. Simulation studies show that using MI to utilise full-cohort information in the analysis of nested case-control and case-cohort studies can result in important gains in efficiency, particularly when a surrogate of the main exposure is available in the full cohort. In simulations, this method outperforms counter-matching in nested case-control studies and a weighted analysis for case-cohort studies, both of which use some full-cohort information. Approximate imputation models perform well except when there are interactions or non-linear terms in the outcome model, where imputation using rejection sampling works well.

  9. Analysis of secondary outcomes in nested case-control study designs.

    PubMed

    Kim, Ryung S; Kaplan, Robert C

    2014-10-30

    One of the main perceived advantages of using a case-cohort design compared with a nested case-control design in an epidemiologic study is the ability to evaluate with the same subcohort outcomes other than the primary outcome of interest. In this paper, we show that valid inferences about secondary outcomes can also be achieved in nested case-control studies by using the inclusion probability weighting method in combination with an approximate jackknife standard error that can be computed using existing software. Simulation studies demonstrate that when the sample size is sufficient, this approach yields valid type 1 error and coverage rates for the analysis of secondary outcomes in nested case-control designs. Interestingly, the statistical power of the nested case-control design was comparable with that of the case-cohort design when the primary and secondary outcomes were positively correlated. The proposed method is illustrated with the data from a cohort in Cardiovascular Health Study to study the association of C-reactive protein levels and the incidence of congestive heart failure.

  10. The role of the CHRNA4 gene in Internet addiction: a case-control study.

    PubMed

    Montag, Christian; Kirsch, Peter; Sauer, Carina; Markett, Sebastian; Reuter, Martin

    2012-09-01

    Recent studies from Asia provided first evidence for a molecular genetic link between serotonergic and dopaminergic neurotransmission and Internet addiction. The present report offers data on a new candidate gene in the investigation of Internet addiction-the gene coding for the nicotinic acetylcholine receptor subunit alpha 4 (CHRNA4). A case-control study was carried out. The participants were recruited from a large gene data bank, including people from the general population and from a university setting. A total of 132 participants with problematic Internet use and 132 age- and sex-matched controls participated in the study. Participants provided DNA samples and filled in the Internet Addiction Test Questionnaire. The T- variant (CC genotype) of the rs1044396 polymorphism on the CHRNA4 gene occurred significantly more frequently in the case group. Further analyses revealed that this effect was driven by females. Combined with the findings from other studies, the present data point in the direction that rs1044396 exerts pleiotropic effects on a vast range of behaviors, including cognition, emotion, and addiction.

  11. Nutritional Status of Children with Autism Spectrum Disorders (ASDs): A Case-Control Study

    ERIC Educational Resources Information Center

    Marí-Bauset, Salvador; Llopis-González, Agustín; Zazpe-García, Itziar; Marí-Sanchis, Amelia; Morales-Suárez-Varela, María

    2015-01-01

    Children with autism spectrum disorder (ASD) have problems of food selectivity, implying risks of nutritional deficiencies. The aim was to compare intakes of macro and micronutrients and body mass index in ASD and typically developing (TD) children. In a case--control study, 3-day food diaries and anthropometric measurements were completed for ASD…

  12. Toxoplasmosis gondii and schizophrenia: a case control study in a low Toxoplasma gondii seroprevalence Mexican population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are conflicting reports concerning the association of T. gondii infection and schizophrenia. Therefore, we determined such association in a Mexican population of Mestizo ethnicity. Through a case-control study design, 50 schizophrenic patients and 150 control subjects matched by gender, age, r...

  13. COMPARISON OF GEOCODING METHODS USED IN CASE-CONTROL STUDY OF AIR QUALITY AND BIRTH DEFECTS

    EPA Science Inventory

    Introduction: Accurate geocoding of maternal residence is critical to the success of an ongoing case-control study of exposure to five criteria air pollutants and the risk of selected birth defects in seven Texas counties between 1997 and 2000. The geocoded maternal residence a...

  14. A Case Control Study of Suicide and Attempted Suicide in Older Adults.

    ERIC Educational Resources Information Center

    Beautrais, Annette L.

    2002-01-01

    Risk factors for serious suicidal behavior among older adults were examined in a case control study of adults aged 55 and older who died by suicide or made suicide attempts and who were compared with randomly selected comparison subjects. Multivariate analyses suggested that mood disorders were the most significant risk factor for suicidal…

  15. Uncovering selection bias in case-control studies using Bayesian post-stratification.

    PubMed

    Geneletti, S; Best, N; Toledano, M B; Elliott, P; Richardson, S

    2013-07-10

    Case-control studies are particularly prone to selection bias, which can affect odds ratio estimation. Approaches to discovering and adjusting for selection bias have been proposed in the literature using graphical and heuristic tools as well as more complex statistical methods. The approach we propose is based on a survey-weighting method termed Bayesian post-stratification and follows from the conditional independences that characterise selection bias. We use our approach to perform a selection bias sensitivity analysis by using ancillary data sources that describe the target case-control population to re-weight the odds ratio estimates obtained from the study. The method is applied to two case-control studies, the first investigating the association between exposure to electromagnetic fields and acute lymphoblastic leukaemia in children and the second investigating the association between maternal occupational exposure to hairspray and a congenital anomaly in male babies called hypospadias. In both case-control studies, our method showed that the odds ratios were only moderately sensitive to selection bias.

  16. Study designs may influence results: the problems with questionnaire-based case-control studies on the epidemiology of glioma.

    PubMed

    Johansen, Christoffer; Schüz, Joachim; Andreasen, Anne-Marie Serena; Dalton, Susanne Oksbjerg

    2017-03-28

    Glioma is a rare brain tumour with a very poor prognosis and the search for modifiable factors is intense. We reviewed the literature concerning risk factors for glioma obtained in case-control designed epidemiological studies in order to discuss the influence of this methodology on the observed results. When reviewing the association between three exposures, medical radiation, exogenous hormone use and allergy, we critically appraised the evidence from both case-control and cohort studies. For medical radiation and hormone replacement therapy (HRT), questionnaire-based case-control studies appeared to show an inverse association, whereas nested case-control and cohort studies showed no association. For allergies, the inverse association was observed irrespective of study design. We recommend that the questionnaire-based case-control design be placed lower in the hierarchy of studies for establishing cause-and-effect for diseases such as glioma. We suggest that a state-of-the-art case-control study should, as a minimum, be accompanied by extensive validation of the exposure assessment methods and the representativeness of the study sample with regard to the exposures of interest. Otherwise, such studies cannot be regarded as 'hypothesis testing' but only 'hypothesis generating'. We consider that this holds true for all questionnaire-based case-control studies on cancer and other chronic diseases, although perhaps not to the same extent for each exposure-outcome combination.

  17. Excess relative risk as an effect measure in case-control studies of rare diseases.

    PubMed

    Lee, Wen-Chung

    2014-01-01

    Epidemiologists often use ratio-type indices (rate ratio, risk ratio and odds ratio) to quantify the association between exposure and disease. By comparison, less attention has been paid to effect measures on a difference scale (excess rate or excess risk). The excess relative risk (ERR) used primarily by radiation epidemiologists is of peculiar interest here, in that it involves both difference and ratio operations. The ERR index (but not the difference-type indices) is estimable in case-control studies. Using the theory of sufficient component cause model, the author shows that when there is no mechanistic interaction (no synergism in the sufficient cause sense) between the exposure under study and the stratifying variable, the ERR index (but not the ratio-type indices) in a rare-disease case-control setting should remain constant across strata and can therefore be regarded as a common effect parameter. By exploiting this homogeneity property, the related attributable fraction indices can also be estimated with greater precision. The author demonstrates the methodology (SAS codes provided) using a case-control dataset, and shows that ERR preserves the logical properties of the ratio-type indices. In light of the many desirable properties of the ERR index, the author advocates its use as an effect measure in case-control studies of rare diseases.

  18. Genetic Structure, Self-Identified Race/Ethnicity, and Confounding in Case-Control Association Studies

    PubMed Central

    Tang, Hua; Quertermous, Tom; Rodriguez, Beatriz; Kardia, Sharon L. R.; Zhu, Xiaofeng; Brown, Andrew; Pankow, James S.; Province, Michael A.; Hunt, Steven C.; Boerwinkle, Eric; Schork, Nicholas J.; Risch, Neil J.

    2005-01-01

    We have analyzed genetic data for 326 microsatellite markers that were typed uniformly in a large multiethnic population-based sample of individuals as part of a study of the genetics of hypertension (Family Blood Pressure Program). Subjects identified themselves as belonging to one of four major racial/ethnic groups (white, African American, East Asian, and Hispanic) and were recruited from 15 different geographic locales within the United States and Taiwan. Genetic cluster analysis of the microsatellite markers produced four major clusters, which showed near-perfect correspondence with the four self-reported race/ethnicity categories. Of 3,636 subjects of varying race/ethnicity, only 5 (0.14%) showed genetic cluster membership different from their self-identified race/ethnicity. On the other hand, we detected only modest genetic differentiation between different current geographic locales within each race/ethnicity group. Thus, ancient geographic ancestry, which is highly correlated with self-identified race/ethnicity—as opposed to current residence—is the major determinant of genetic structure in the U.S. population. Implications of this genetic structure for case-control association studies are discussed. PMID:15625622

  19. Blessed be the Children: A Case-Control Study of Sexual Abusers in the Catholic Church.

    PubMed

    Calkins, Cynthia; Fargo, Jamison; Jeglic, Elizabeth; Terry, Karen

    2015-08-01

    Individuals working in churches and other youth-serving institutions have a unique level of access to children, yet the problem of sexual abuse in institutional settings has received scant research attention. To address this gap, we analyzed data from a large sample of clergy (N = 1,121) and applied a social-ecological model of offending to identify risk factors for sexual abuse perpetration. Using a case-control study design that compared clergy sexual abusers with three control groups of clergy, this study focuses specifically on individual-, relationship-, and community-level factors associated with a higher risk of abuse in professional populations. Findings revealed that clergy sexual abusers tended to have more truncated pre-seminary dating histories, and that their dating and sexual partners were more likely to have been male than female. Self-reported sexual abuse history was associated with a greater likelihood of sexual abuse perpetration among clergy. Clergy abusers tended to be more involved with youth and adolescents in their ministries; however, they were observed to relate less well to youth and adolescents than their clergy counterparts. Given widespread changes in our cultural understanding of abuse as well as more specific changes in the organizational approach to seminary education, these differences underscore the role that youth-serving institutions and society can have in the primary prevention of child sexual abuse.

  20. Occupational exposure to electromagnetic fields and acute leukaemia: analysis of a case-control study

    PubMed Central

    Willett, E; McKinney, P; Fear, N; Cartwright, R; Roman, E

    2003-01-01

    Aims: To investigate whether the risk of acute leukaemia among adults is associated with occupational exposure to electromagnetic fields. Methods: Probable occupational exposure to electromagnetic fields at higher than typical residential levels was investigated among 764 patients diagnosed with acute leukaemia during 1991–96 and 1510 sex and age matched controls. A job exposure matrix was applied to the self reported employment histories to determine whether or not a subject was exposed to electromagnetic fields. Risks were assessed using conditional logistic regression for a matched analysis. Results: Study subjects considered probably ever exposed to electromagnetic fields at work were not at increased risk of acute leukaemia compared to those considered never exposed. Generally, no associations were observed on stratification by sex, leukaemia subtype, number of years since exposure stopped, or occupation; there was no evidence of a dose-response effect using increasing number of years exposed. However, relative to women considered never exposed, a significant excess of acute lymphoblastic leukaemia was observed among women probably exposed to electromagnetic fields at work that remained increased irrespective of time prior to diagnosis or job ever held. Conclusion: This large population based case-control study found little evidence to support an association between occupational exposure to electromagnetic fields and acute leukaemia. While an excess of acute lymphoblastic leukaemia among women was observed, it is unlikely that occupational exposure to electromagnetic fields was responsible, given that increased risks remained during periods when exposure above background levels was improbable. PMID:12883018

  1. A review of case-control studies on the risk factors for the development of autoimmune blistering diseases.

    PubMed

    Oh, D D; Zhao, C Y; Murrell, D F

    2016-04-01

    Autoimmune blistering diseases (AIBD) are a group of rare but potentially fatal diseases characterized by the production of autoantibodies directed against the structural proteins of the skin. Much has been published on the clinical manifestation and interventional options for AIBD, especially on the more common subtypes such as bullous pemphigoid, pemphigus vulgaris (PV) and pemphigus foliaceus (PF). However, the aetiology of AIBD remains unknown. We aim to provide an overview of published case-control studies focussing on the non-genetic aetiological factors of bullous pemphigoid, PV and/or PF. The relevant studies were appraised for their validity and results. Our results showed that a large proportion of the studies had inconclusive results due to compromised study methodologies. Moreover, there were no identified case-control studies that investigated the possible associations between bullous pemphigoid and patient environment, or the potential links between pemphigus and drugs. Hence, a case-control study with a higher quality design addressing these shortcomings would contribute greatly to our knowledge of AIBD.

  2. Ecological versus case-control studies for testing a linear-no threshold dose-response relationship.

    PubMed

    Cohen, B L

    1990-09-01

    The two basic problems with ecological studies are (A) individuals studied are not necessarily the individuals who are at risk, and (B) they are very vulnerable to confounding factors. It is shown that where the study is designed to test a linear-no threshold dose-response theory, (A) does not apply. Where the ecological study deals with the average dose and response in a large number of US counties, the available data and computer capability for reducing effects of confounders are so powerful that (B) may be no more important for the ecological than for a case-control study. The migration problem is treated and found to be relatively unimportant.

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

    PubMed

    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.

  4. Lung Cancer and Occupation in a Population-based Case-Control Study

    PubMed Central

    Consonni, Dario; De Matteis, Sara; Lubin, Jay H.; Wacholder, Sholom; Tucker, Margaret; Pesatori, Angela Cecilia; Caporaso, Neil E.; Bertazzi, Pier Alberto; Landi, Maria Teresa

    2010-01-01

    The authors examined the relation between occupation and lung cancer in the large, population-based Environment And Genetics in Lung cancer Etiology (EAGLE) case-control study. In 2002–2005 in the Lombardy region of northern Italy, 2,100 incident lung cancer cases and 2,120 randomly selected population controls were enrolled. Lifetime occupational histories (industry and job title) were coded by using standard international classifications and were translated into occupations known (list A) or suspected (list B) to be associated with lung cancer. Smoking-adjusted odds ratios and 95% confidence intervals were calculated with logistic regression. For men, an increased risk was found for list A (177 exposed cases and 100 controls; odds ratio = 1.74, 95% confidence interval: 1.27, 2.38) and most occupations therein. No overall excess was found for list B with the exception of filling station attendants and bus and truck drivers (men) and launderers and dry cleaners (women). The authors estimated that 4.9% (95% confidence interval: 2.0, 7.8) of lung cancers in men were attributable to occupation. Among those in other occupations, risk excesses were found for metal workers, barbers and hairdressers, and other motor vehicle drivers. These results indicate that past exposure to occupational carcinogens remains an important determinant of lung cancer occurrence. PMID:20047975

  5. Outlining a Population "at Risk" of Parkinson's Disease: Evidence from a Case-Control Study.

    PubMed

    Schirinzi, Tommaso; Martella, Giuseppina; D'Elia, Alessio; Di Lazzaro, Giulia; Imbriani, Paola; Madeo, Graziella; Monaco, Leonardo; Maltese, Marta; Pisani, Antonio

    2016-01-01

    The multifactorial pathogenesis of Parkinson's Disease (PD) requires a careful identification of populations "at risk" of developing the disease. In this case-control study we analyzed a large Italian population, in an attempt to outline general criteria to define a population "at risk" of PD. We enrolled 300 PD patients and 300 controls, gender and age matched, from the same urban geographical area. All subjects were interviewed on demographics, family history of PD, occupational and environmental toxicants exposure, smoking status, and alcohol consumption. A sample of 65 patients and 65 controls also underwent serum dosing of iron, copper, mercury, and manganese by means of Inductively Coupled-Plasma-Mass-Spectrometry (ICP-MS). Positive family history, toxicants exposure, non-current-smoker, and alcohol nonconsumer status occurred as significant risk factors in our population. The number of concurring risk factors overlapping in the same subject impressively increased the overall risk. No significant differences were measured in the metal serum levels. Our findings indicate that combination of three to four concurrent PD-risk factors defines a condition "at risk" of PD. A simple stratification, based on these questionnaires, might be of help in identifying subjects suitable for neuroprotective strategies.

  6. Occupations and lung cancer: a population-based case-control study in British Columbia.

    PubMed

    Yenugadhati, Nagarajkumar; Birkett, Nicholas J; Momoli, Franco; Krewski, Daniel

    2009-01-01

    An investigation based on a large population-based case-control study in British Columbia, Canada, was conducted to identify high-risk occupations for lung cancer by histological subtypes. Subjects were 14,755 male incident cancer cases for whom lifetime occupational histories and information on smoking and relevant covariates were collected. Occupational associations for 2998 lung cancer cases, including histological subtypes, were assessed by logistic regression using other cancer cases, excluding smoking-related cancers, as controls. An excess risk of lung cancer was found among workers in metal processing, bakers, and ship deck crew for all histological subtypes, and construction workers, chefs and cooks, and medical workers for specific histological subtypes. Occupational associations that are unique to histological subtypes of lung cancer were identified. Owing to a scarcity of literature in this area, future research needs to focus on confirming these histological associations, and identifying the risk from key exposures found within these occupations (e.g., medical radiation, electromagnetic fields, and cooking fumes).

  7. Lung cancer and occupation in a population-based case-control study.

    PubMed

    Consonni, Dario; De Matteis, Sara; Lubin, Jay H; Wacholder, Sholom; Tucker, Margaret; Pesatori, Angela Cecilia; Caporaso, Neil E; Bertazzi, Pier Alberto; Landi, Maria Teresa

    2010-02-01

    The authors examined the relation between occupation and lung cancer in the large, population-based Environment And Genetics in Lung cancer Etiology (EAGLE) case-control study. In 2002-2005 in the Lombardy region of northern Italy, 2,100 incident lung cancer cases and 2,120 randomly selected population controls were enrolled. Lifetime occupational histories (industry and job title) were coded by using standard international classifications and were translated into occupations known (list A) or suspected (list B) to be associated with lung cancer. Smoking-adjusted odds ratios and 95% confidence intervals were calculated with logistic regression. For men, an increased risk was found for list A (177 exposed cases and 100 controls; odds ratio = 1.74, 95% confidence interval: 1.27, 2.38) and most occupations therein. No overall excess was found for list B with the exception of filling station attendants and bus and truck drivers (men) and launderers and dry cleaners (women). The authors estimated that 4.9% (95% confidence interval: 2.0, 7.8) of lung cancers in men were attributable to occupation. Among those in other occupations, risk excesses were found for metal workers, barbers and hairdressers, and other motor vehicle drivers. These results indicate that past exposure to occupational carcinogens remains an important determinant of lung cancer occurrence.

  8. Case-control study of cumulative cigarette tar exposure and lung and upper aerodigestive tract cancers.

    PubMed

    Meyers, Travis J; Chang, Shen-Chih; Chang, Po-Yin; Morgenstern, Hal; Tashkin, Donald P; Rao, Jian-Yu; Cozen, Wendy; Mack, Thomas M; Zhang, Zuo-Feng

    2017-05-01

    The development of comprehensive measures for tobacco exposure is crucial to specify effects on disease and inform public health policy. In this population-based case-control study, we evaluated the associations between cumulative lifetime cigarette tar exposure and cancers of the lung and upper aerodigestive tract (UADT). The study included 611 incident cases of lung cancer; 601 cases of UADT cancers (oropharyngeal, laryngeal and esophageal cancers); and 1,040 cancer-free controls. We estimated lifetime exposure to cigarette tar based on tar concentrations abstracted from government cigarette records and self-reported smoking histories derived from a standardized questionnaire. We analyzed the associations for cumulative tar exposure with lung and UADT cancer, overall and according to histological subtype. Cumulative tar exposure was highly correlated with pack-years among ever smoking controls (Pearson coefficient = 0.90). The adjusted odds ratio (95% confidence limits) for the estimated effect of about 1 kg increase in tar exposure (approximately the interquartile range in all controls) was 1.61 (1.50, 1.73) for lung cancer and 1.21 (1.13, 1.29) for UADT cancers. In general, tar exposure was more highly associated with small, squamous and large cell lung cancer than adenocarcinoma. With additional adjustment for pack-years, positive associations between tar and lung cancer were evident, particularly for small cell and large cell subtypes. Therefore, incorporating the composition of tobacco carcinogens in lifetime smoking exposure may improve lung cancer risk estimation. This study does not support the claim of a null or inverse association between "low exposure" to tobacco smoke and risk of these cancer types.

  9. Case Control Study of Type II Decompression Sickness Associated with Patent Foramen Ovale in Experimental No-Decompression Dives

    DTIC Science & Technology

    2010-05-01

    Navy Experimental Diving Unit 321 Bullfinch Rd. Panama City, FL 32407-7015 TA 07-08 NEDU TR 10-07 May 2010 CASE CONTROL STUDY OF TYPE II...08 NO. 11. TITLE (Include Security Classification) (U) Case Control Study of Type II Decompression Sickness Associated with Patent Foramen Ovale in...Unit, NEDU 19. ABSTRACT (Continue on reverse if necessary and identify by block number) This is a retrospective case control study comparing

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

    PubMed Central

    Niven, Daniel J; Berthiaume, Luc R; Fick, Gordon H; Laupland, Kevin B

    2012-01-01

    Background 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. PMID:22570570

  11. Habitual physical activity and menopausal symptoms: a case-control study.

    PubMed

    Sternfeld, B; Quesenberry, C P; Husson, G

    1999-01-01

    A case-control study design was used to examine whether habitual physical activity prior to the final menstrual period (FMP) was associated with reduced risk of vasomotor and other symptoms during the perimenopausal period. Both cases and controls were identified through a screening interview with randomly selected women members, ages 48-52, of a large health maintenance organization. Cases (n = 82) were defined as women 3-12 months past their FMP who reported regularly having hot flashes or night sweats at least once a day or night during the 3 months following their FMP. Controls (n = 89) were of the same biologic age with respect to the FMP but reported vasomotor symptoms less than once a week during the reference time period. Neither cases nor controls had a history of hormone replacement therapy (HRT), hysterectomy, or bilateral oophorectomy. Case-control status, habitual physical activity (including recreational, housework, child care, and occupational activity), and psychological and somatic symptoms were assessed by self-report. Participation in vigorous recreational activity during the year prior to the FMP was not associated with reduced risk of frequent vasomotor symptoms after the FMP (odds ratio [OR] = 1.03 for a 50-unit increase in activity score, 95% confidence interval [CI] = 0.97-1.1). This lack of relationship was observed in all domains of activity. Factors that were associated with decreased risk included higher body mass index (BMI) (weight in kg/(height in meters)2) (OR = 0.95 per 1 unit increase in BMI, 95% CI = 0.90-1.00) and higher education (having a college degree relative to less education) (OR = 0.56, 95% CI = 0.40-0.80). Physical activity was also unassociated with reduced risk of psychologic distress, depressive feelings, or somatic symptoms, but, relative to controls, having vasomotor symptoms (being a case) was strongly associated with increased risk of experiencing those symptoms (OR ranging from 1.83 for psychologic distress to 2

  12. Polychlorinated Biphenyls, Organochlorines & PD Risk: A Case Control Study in Alaskan Natives

    DTIC Science & Technology

    2011-05-01

    1-0490 TITLE: Polychlorinated Biphenyls, Organochlorines & PD Risk: A Case Control Study in Alaskan Natives PRINCIPAL INVESTIGATOR...Polychlorinated Biphenyls, Organochlorines & PD Risk: A Case 5a. CONTRACT NUMBER W81XWH-04-1-0490 Control Study in Alaskan Natives 5b. GRANT NUMBER...to pol ychlorinated biphenyl (PCBs) residues, organochlorine pesticides and methylmercury with PD. The hy pothesis is that increased exposure to t

  13. Polychlorinated Biphenyls, Organochlorines & PD Risk: A Case Control Study in Alaska

    DTIC Science & Technology

    2010-05-01

    TITLE: Polychlorinated Biphenyls, Organochlorines & PD Risk: A Case Control Study in Alaska PRINCIPAL INVESTIGATOR: Caroline M. Tanner, M.D...2010 4. TITLE AND SUBTITLE Polychlorinated Biphenyls, Organochlorines & PD Risk: A Case 5a. CONTRACT NUMBER W81XWH-04-1-0490 Control Study in...now in progress in Anchorage. 15. SUBJECT TERMS Parkinson’s disease, Polychlorinated biphenyl, Organochlorine pesticides, Methylmercury, Alaska

  14. Accurate liability estimation improves power in ascertained case-control studies.

    PubMed

    Weissbrod, Omer; Lippert, Christoph; Geiger, Dan; Heckerman, David

    2015-04-01

    Linear mixed models (LMMs) have emerged as the method of choice for confounded genome-wide association studies. However, the performance of LMMs in nonrandomly ascertained case-control studies deteriorates with increasing sample size. We propose a framework called LEAP (liability estimator as a phenotype; https://github.com/omerwe/LEAP) that tests for association with estimated latent values corresponding to severity of phenotype, and we demonstrate that this can lead to a substantial power increase.

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

    PubMed

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

    2017-01-18

    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.

  16. Using genetic epidemiology to study Rett syndrome: the design of a case-control study.

    PubMed

    Leonard, H; Fyfe, S; Dye, D; Leonard, S

    2000-01-01

    Rett syndrome is a neurological disorder that is seen almost exclusively in females. Although generally considered to have a genetic basis, the underlying mechanism remains obscure. One favoured hypothesis is that the syndrome is an X-linked dominant disorder, lethal or non-expressed in males. Genealogical research has also suggested that the mode of transmission in Rett syndrome may involve a premutation which over several generations is converted to a full mutation. Geographical clustering has been reported, and it has also been proposed that Rett syndrome is a clinically variable condition and that other neurological disorders may be occurring more commonly in families with Rett syndrome. Other studies have found an apparent increase in intellectual disability and seizures in the extended families of girls with Rett syndrome. The science of genetic epidemiology can be used to identify familial aggregation, which is the clustering of a disorder within a family. We have used a case-control study design to investigate both fetal wastage and familial aggregation of other disorders in families of girls with Rett syndrome. The Australian Rett Syndrome Database provided the source of cases, and control probands were girls of a similar age with normal development. This paper describes the methodology for a case-control study of this rare condition using pedigree data and discusses issues in the collection and evaluation of such data. The use of a control population is an important feature. Both the strengths and the shortcomings of our design are identified, and recommendations are made for future research.

  17. Case-control studies of sporadic enteric infections: a review and discussion of studies conducted internationally from 1990 to 2009.

    PubMed

    Fullerton, Kathleen E; Scallan, Elaine; Kirk, Martyn D; Mahon, Barbara E; Angulo, Frederick J; de Valk, Henriette; van Pelt, Wilfrid; Gauci, Charmaine; Hauri, Anja M; Majowicz, Shannon; O'Brien, Sarah J

    2012-04-01

    Epidemiologists have used case-control studies to investigate enteric disease outbreaks for many decades. Increasingly, case-control studies are also used to investigate risk factors for sporadic (not outbreak-associated) disease. While the same basic approach is used, there are important differences between outbreak and sporadic disease settings that need to be considered in the design and implementation of the case-control study for sporadic disease. Through the International Collaboration on Enteric Disease "Burden of Illness" Studies (the International Collaboration), we reviewed 79 case-control studies of sporadic enteric infections caused by nine pathogens that were conducted in 22 countries and published from 1990 through to 2009. We highlight important methodological and study design issues (including case definition, control selection, and exposure assessment) and discuss how approaches to the study of sporadic enteric disease have changed over the last 20 years (e.g., making use of more sensitive case definitions, databases of controls, and computer-assisted interviewing). As our understanding of sporadic enteric infections grows, methods and topics for case-control studies are expected to continue to evolve; for example, advances in understanding of the role of immunity can be used to improve control selection, the apparent protective effects of certain foods can be further explored, and case-control studies can be used to provide population-based measures of the burden of disease.

  18. Sleep and Parkinson's disease: a review of case-control polysomnography studies.

    PubMed

    Peeraully, Tasneem; Yong, Ming-Hui; Chokroverty, Sudhansu; Tan, Eng-King

    2012-12-01

    The link between Parkinson's disease (PD) and certain primary sleep disorders has yet to be clarified. We performed a systematic review of case-control polysomnography studies to evaluate the relationship between PD and sleep disorders. A PubMed literature search and bibliography review yielded 15 case-control polysomnography studies in patients with PD. Studies differed by recruitment methods, duration of polysomnography monitoring, and sleep parameters measured. Subjective sleepiness was greater in patients than controls (50%-66% vs 2.9%-12%) despite lack of objective increase in daytime sleepiness by mean sleep latency testing. The 4 case-control polysomnography studies investigating rapid eye movement behavior disorder support a higher prevalence in PD (0%-47% vs 0%-1.8% in controls), although differences in diagnostic criteria hamper interpretation. The preponderance of evidence did not support an increased incidence of obstructive sleep apnea (27%-60% vs 13%-65%) or periodic leg movements of sleep in patients compared to controls. Adequately powered, prospective studies with uniform methodology and healthy controls are needed to further address the association and pathophysiological significance between PD and sleep problems.

  19. Polychlorinated Biphenyls, Organochlorines & PD Risk: A Case Control Study in Alaska

    DTIC Science & Technology

    2009-05-01

    Organochlorines & PD Risk: A Case Control Study in Alaska 5b. GRANT NUMBER W81XWH-04-1-0490 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...biphenyl (PCBs) residues, organochlorine pesticides and methylmercury with PD. The hypothesis is that increased exposure to these compounds will be...Parkinson’s disease, polychlorinated biphenyl, organochlorine pesticides, methylmercury, Alaska natives, neurodegeneration 16. SECURITY

  20. Acute myeloid leukemia in adults: a case-control study in Yorkshire.

    PubMed

    Cartwright, R A; Darwin, C; McKinney, P A; Roberts, B; Richards, I D; Bird, C C

    1988-10-01

    This paper reports the results of a case-control analysis of 161 cases of acute myeloid leukemia and 310 matched hospital controls. The patients were interviewed between 1982 and 1986. The study shows a weak association for cases with previous malignant disease. Furnace workers show excess risks. Urticaria and vertigo are in excess, as well as some aspects of family medical histories, including multiple sclerosis and cases of leukemia/lymphoma in blood relations.

  1. Impact of waning acquired immunity and asymptomatic infections on case-control studies for enteric pathogens.

    PubMed

    Havelaar, Arie H; Swart, Arno

    2016-12-01

    Case-control studies of outbreaks and of sporadic cases of infectious diseases may provide a biased estimate of the infection rate ratio, due to selecting controls that are not at risk of disease. We use a dynamic mathematical model to explore biases introduced in results drawn from case-control studies of enteric pathogens by waning and boosting of immunity, and by asymptomatic infections, using Campylobacter jejuni as an example. Individuals in the population are either susceptible (at risk of infection and disease), fully protected (not at risk of either) or partially protected (at risk of infection but not of disease). The force of infection is a function of the exposure frequency and the exposure dose. We show that the observed disease odds ratios are indeed strongly biased towards the null, i.e. much lower than the infection rate ratio, and furthermore even not proportional to it. The bias could theoretically be controlled by sampling controls only from the reservoir of susceptible individuals. The population at risk is in a dynamic equilibrium, and cannot be identified as those who are not and have never experienced disease. Individual-level samples to measure protective immunity would be required, complicating the design, cost and execution of case-control studies.

  2. Multivariate multidistance tests for high-dimensional low sample size case-control studies.

    PubMed

    Marozzi, Marco

    2015-04-30

    A class of multivariate tests for case-control studies with high-dimensional low sample size data and with complex dependence structure, which are common in medical imaging and molecular biology, is proposed. The tests can be applied when the number of variables is much larger than the number of subjects and when the underlying population distributions are heavy-tailed or skewed. As a motivating application, we consider a case-control study where phase-contrast cinematic cardiovascular magnetic resonance imaging has been used to compare many cardiovascular characteristics of young healthy smokers and young healthy non-smokers. The tests are based on the combination of tests on interpoint distances. It is theoretically proved that the tests are exact, unbiased and consistent. It is shown that the tests are very powerful under normal, heavy-tailed and skewed distributions. The tests can also be applied to case-control studies with high-dimensional low sample size data from other medical imaging techniques (like computed tomography or X-ray radiography), chemometrics and microarray data (proteomics and transcriptomics).

  3. Leptospira Exposure and Waste Pickers: A Case-Control Seroprevalence Study in Durango, Mexico

    PubMed Central

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

    2015-01-01

    Background Infection with Leptospira may occur by contact with Leptospira-infected animals. Waste pickers are in contact with rodents and dogs while picking in the garbage. Whether waste pickers are at risk for Leptospira infection is largely unknown. This study was aimed to determine the association of Leptospira IgG seroprevalence with the occupation of waste picking, and to determine the epidemiological characteristics of the waste pickers with Leptospira exposure. Methods Through a case-control study, we determined the seroprevalence of anti-Leptospira IgG antibodies in 90 waste pickers and 90 age- and gender-matched control subjects in Durango City, Mexico using an enzyme immunoassay. Data were analyzed by bivariate and multivariate analyses. Results The prevalence of anti-Leptospira IgG antibodies was similar in waste pickers (4/90: 4.4%) to that in control subjects (5/90: 5.6%) (P = 1.00). Bivariate analysis showed that Leptospira exposure in waste pickers was associated with increasing age (P = 0.009), no education (P = 0.008), and consumption of rat meat (P = 0.04). However, these associations were no longer found by multivariate analysis. Leptospira exposure in waste pickers was not associated with health status, duration in the activity, wearing hand gloves and facemasks, history of injuries with sharp material of the garbage, or contact with animals or soil. Conclusions This is the first study about Leptospira exposure in waste pickers. Results suggest that waste pickers are not at increasing risk for Leptospira exposure in Durango City, Mexico. Further research with a larger sample size to elucidate the association of Leptospira exposure with waste picking activity is needed. PMID:26124911

  4. Association between obesity and the risk of malignant lymphoma in Japanese: a case-control study.

    PubMed

    Kanda, Junya; Matsuo, Keitaro; Suzuki, Takeshi; Hosono, Satoyo; Ito, Hidemi; Ichinohe, Tatsuo; Seto, Masao; Morishima, Yasuo; Tajima, Kazuo; Tanaka, Hideo

    2010-05-15

    Although marked differences in anthropometric characteristics and malignant lymphoma (ML) incidence suggest that the association between obesity and ML risk in Asian and non-Asian populations may differ, few studies have investigated this association in Asian populations. Here, we conducted a sex- and age-matched case-control study in a Japanese population using 782 cases and 3,910 noncancer controls in the hospital-based Epidemiological Research Program at Aichi Cancer Center Hospital. Odds ratios (ORs) and 95% confidence intervals (CIs) for anthropometric characteristics were estimated using a conditional logistic regression model that incorporated smoking and alcohol intake. Recent body weight and body mass index (BMI) showed marginally significant association with ML risk (ORs [95% CIs] per 5-unit increase in recent weight and BMI; 1.04 [0.99-1.09] and 1.11 [0.98-1.27], respectively). On the other hand, weight and BMI in early adulthood exhibited a strong association with ML risk (ORs [95% CIs] per 5-unit increase in early adulthood weight and BMI; 1.11 [1.05-1.18] and 1.33 [1.13-1.55], respectively). Further, in women, a BMI of 25.0-29.9 kg/m(2), defined as obesity in Asian populations, during early adulthood was significantly associated with ML risk compared to the normal range of 18.5-22.9 kg/m(2). By histological ML subtype, the point estimates of ORs for obesity relative to normal weight in early adulthood were over unity for non-Hodgkin lymphoma (NHL) as a whole and significant for diffuse large B-cell lymphoma (DLBCL). In conclusion, our study in Japanese subjects suggested that early adulthood obesity is associated with the risk of NHL, particularly DLBCL.

  5. A double robust approach to causal effects in case-control studies.

    PubMed

    Rose, Sherri; van der Laan, Mark

    2014-03-15

    In a recent issue of the Journal, VanderWeele and Vansteelandt (Am J Epidemiol. 2011;174(10):1197-1203) discussed an inverse probability weighting method for case-control studies that could be used to estimate an additive interaction effect, referred to as the "relative excess risk due to interaction." In this article, we reinforce the well-known disadvantages of inverse probability weighting and comment on the desirability of the described parameter. Further, we review an existing double robust estimator not considered by VanderWeele and Vansteelandt, the case-control-weighted targeted maximum likelihood estimator, which has improved properties in comparison with a previously described inverse-probability-weighted estimator. This targeted maximum likelihood estimator can be used to target various parameters of interest, and its implementation has been described previously for the risk difference, relative risk, and odds ratio.

  6. Tests for gene-environment interaction from case-control data: a novel study of type I error, power and designs.

    PubMed

    Mukherjee, Bhramar; Ahn, Jaeil; Gruber, Stephen B; Rennert, Gad; Moreno, Victor; Chatterjee, Nilanjan

    2008-11-01

    To evaluate the risk of a disease associated with the joint effects of genetic susceptibility and environmental exposures, epidemiologic researchers often test for non-multiplicative gene-environment effects from case-control studies. In this article, we present a comparative study of four alternative tests for interactions: (i) the standard case-control method; (ii) the case-only method, which requires an assumption of gene-environment independence for the underlying population; (iii) a two-step method that decides between the case-only and case-control estimators depending on a statistical test for the gene-environment independence assumption and (iv) a novel empirical-Bayes (EB) method that combines the case-control and case-only estimators depending on the sample size and strength of the gene-environment association in the data. We evaluate the methods in terms of integrated Type I error and power, averaged with respect to varying scenarios for gene-environment association that are likely to appear in practice. These unique studies suggest that the novel EB procedure overall is a promising approach for detection of gene-environment interactions from case-control studies. In particular, the EB procedure, unlike the case-only or two-step methods, can closely maintain a desired Type I error under realistic scenarios of gene-environment dependence and yet can be substantially more powerful than the traditional case-control analysis when the gene-environment independence assumption is satisfied, exactly or approximately. Our studies also reveal potential utility of some non-traditional case-control designs that samples controls at a smaller rate than the cases. Apart from the simulation studies, we also illustrate the different methods by analyzing interactions of two commonly studied genes, N-acetyl transferase type 2 and glutathione s-transferase M1, with smoking and dietary exposures, in a large case-control study of colorectal cancer.

  7. Linezolid-resistant staphylococcal bacteraemia: A multicentre case-case-control study in Italy.

    PubMed

    Russo, Alessandro; Campanile, Floriana; Falcone, Marco; Tascini, Carlo; Bassetti, Matteo; Goldoni, Paola; Trancassini, Maria; Della Siega, Paola; Menichetti, Francesco; Stefani, Stefania; Venditti, Mario

    2015-03-01

    The aim of this multicentre study was to analyse the characteristics of patients with bloodstream infections due to staphylococcal strains resistant to linezolid. This was a retrospective case-case-control study of patients hospitalised in three large teaching hospitals in Italy. A linezolid-resistant (LIN-R) Staphylococcus spp. group and a linezolid-susceptible (LIN-S) Staphylococcus spp. group were compared with control patients to determine the clinical features and factors associated with isolation of LIN-R strains. All LIN-R Staphylococcus spp. strains underwent molecular typing. Compared with the LIN-S group, central venous catheters were the main source of infection in the LIN-R group. The LIN-R and LIN-S groups showed a similar incidence of severe sepsis or septic shock, and both showed a higher incidence of these compared with the control group. Overall, patients in the LIN-R group had a higher 30-day mortality rate. Multivariate analysis found previous linezolid therapy, linezolid therapy >14 days, antibiotic therapy in the previous 30 days, antibiotic therapy >14 days, previous use of at least two antibiotics and hospitalisation in the previous 90 days as independent risk factors associated with isolation of a LIN-R strain. The G2576T mutation in domain V of 23S rRNA was the principal mechanism of resistance; only one strain of Staphylococcus epidermidis carried the cfr methylase gene (A2503), together with L4 insertion (71GGR72) and L3 substitution (H146Q). LIN-R strains are associated with severe impairment of clinical conditions and unfavourable patient outcomes. Reinforcement of infection control measures may have an important role in preventing these infections.

  8. Background radiation and childhood leukemia: A nationwide register-based case-control study.

    PubMed

    Nikkilä, Atte; Erme, Sini; Arvela, Hannu; Holmgren, Olli; Raitanen, Jani; Lohi, Olli; Auvinen, Anssi

    2016-11-01

    High doses of ionizing radiation are an established cause of childhood leukemia. However, substantial uncertainty remains about the effect of low doses of radiation, including background radiation and potential differences between genetic subgroups of leukemia have rarely been explored. We investigated the effect of the background gamma radiation on childhood leukemia using a nationwide register-based case-control study. For each of the 1,093 cases, three age- and gender matched controls were selected (N = 3,279). Conditional logistic regression analyses were adjusted for confounding by Down syndrome, birth weight (large for gestational age), and maternal smoking. Complete residential histories and previously collected survey data of the background gamma radiation in Finland were used to assess the exposure of the study subjects to indoor and outdoor gamma radiation. Overall, background gamma radiation showed a non-significant association with the OR of childhood leukemia (OR 1.01, 95% CI 0.97, 1.05 for 10 nSv/h increase in average equivalent dose rate to red bone marrow). In subgroup analyses, age group 2-<7 years displayed a larger effect (OR 1.27, 95% CI 1.01, 1.60 for 1 mSv increase in equivalent cumulative dose to red bone marrow). Suggestive difference in OR by genetic subtype was found. Our results provide further support to the notion that low doses of ionizing radiation increase the risk for childhood leukemia, particularly at age 2-<7 years. Our findings suggest a larger effect of radiation on leukemia with high hyperpdiploidy than other subgroups, but this result requires further confirmation.

  9. Epistatic Module Detection for Case-Control Studies: A Bayesian Model with a Gibbs Sampling Strategy

    PubMed Central

    Tang, Wanwan; Wu, Xuebing; Jiang, Rui; Li, Yanda

    2009-01-01

    The detection of epistatic interactive effects of multiple genetic variants on the susceptibility of human complex diseases is a great challenge in genome-wide association studies (GWAS). Although methods have been proposed to identify such interactions, the lack of an explicit definition of epistatic effects, together with computational difficulties, makes the development of new methods indispensable. In this paper, we introduce epistatic modules to describe epistatic interactive effects of multiple loci on diseases. On the basis of this notion, we put forward a Bayesian marker partition model to explain observed case-control data, and we develop a Gibbs sampling strategy to facilitate the detection of epistatic modules. Comparisons of the proposed approach with three existing methods on seven simulated disease models demonstrate the superior performance of our approach. When applied to a genome-wide case-control data set for Age-related Macular Degeneration (AMD), the proposed approach successfully identifies two known susceptible loci and suggests that a combination of two other loci—one in the gene SGCD and the other in SCAPER—is associated with the disease. Further functional analysis supports the speculation that the interaction of these two genetic variants may be responsible for the susceptibility of AMD. When applied to a genome-wide case-control data set for Parkinson's disease, the proposed method identifies seven suspicious loci that may contribute independently to the disease. PMID:19412524

  10. Risk factors for acanthamoeba keratitis in contact lens users: a case-control study.

    PubMed Central

    Radford, C. F.; Bacon, A. S.; Dart, J. K.; Minassian, D. C.

    1995-01-01

    OBJECTIVE--To investigate reasons for an increase in cases of Acanthamoeba keratitis related to contact lenses. DESIGN--Case-control study. Cases were contact lens related acanthamoeba keratitis patients treated between 1 September 1989 and 31 August 1992. Controls were lens users without lens related disease who presented as new patients to the casualty department from 1 March 1992 to 31 August 1992. All subjects completed a questionnaire detailing lens use and hygiene practices. SETTING--Eye hospital. SUBJECTS--35 cases with acanthamoeba keratitis and 378 controls. MAIN OUTCOME MEASURES--Relative risks comparing different contact lens types, socioeconomic classification, age, sex, lens use, lens wearing experience, hygiene compliance, and hygiene systems. RESULTS--The crude relative risk for developing acanthamoeba keratitis with the use of daily wear disposable lenses was 49.45 (95% confidence interval 6.53 to 2227; P < 0.001) compared with conventional soft lenses (the referent). Multivariable analysis showed that this increased risk could be largely attributed to lack of disinfection (relative risk 55.86 (10 to 302); P < 0.001) and use of chlorine based disinfection (14.63 (2.8 to 76); P = 0.001) compared with other chemical systems (the referent). None of the other outcome measures showed a significant association. CONCLUSIONS--Both failure to disinfect daily wear soft contact lenses and the use of chlorine release lens disinfection systems, which have little protective effect against the organism, are major risk factors for acanthamoeba keratitis. These risks have been particularly common in disposable lens use. Over 80% of acanthamoeba keratitis could be avoided by the use of lens disinfection systems that are effective against the organism. PMID:7787645

  11. Occupation and lung cancer in Shanghai: a case-control study.

    PubMed Central

    Levin, L I; Zheng, W; Blot, W J; Gao, Y T; Fraumeni, J F

    1988-01-01

    Occupation was evaluated as a potential risk factor for lung cancer as part of a large population based case-control study conducted in the ten urban districts of Shanghai. A total of 733 newly diagnosed cases of male lung cancer and 760 controls selected from the general population was interviewed to obtain lifetime occupational histories and information on smoking and other factors. Of the approximately 25 major industrial titles examined, significantly raised risks, adjusted for smoking, were found for employment in agricultural production (odds ratio (OR) = 1.6, 95% confidence interval (CI) = 1.0-2.6). A concomitant increase was detected for farmers (OR = 1.6, 95% CI = 1.0-2.5) when 35 major occupational titles were examined. There was a 70% excess among workers in the chemical industry (OR = 1.7, 95% CI = 0.9-3.1) and a significant decrease among textile industry workers (OR = 0.7, 95% CI = 0.5-1.0). Raised risks of 30% to 80% were associated with reported job exposures to wood and coal dusts, smoke from burning fuels, and chemical fumes. Employment categories were also examined for 672 cases and 735 controls among women, but small numbers in many of the industrial and occupational categories precluded detailed analyses. The largest excess risk among women (OR = 5.1, 95% CI 1.3-23.5) was among glass products workers. Although cigarette smoking was the dominant cause of lung cancer among men and a significant risk factor among women in Shanghai, these findings suggest the importance of certain workplace exposures and offer leads to occupational carcinogens. PMID:3395581

  12. Case control study to identify risk factors for simple colonic obstruction and distension colic in horses.

    PubMed

    Hillyer, M H; Taylor, F G R; Proudman, C J; Edwards, G B; Smith, J E; French, N P

    2002-07-01

    A case control study was performed to identify risk factors for colic caused by simple colonic obstruction and distension (SCOD) in the horse. Case horses were recruited from 2 veterinary school clinics. Control horses were population based and matched by time of year. A number of risk factors were considered in the following areas: general carer and premises information; exercise information; husbandry information (housing- and pasture-related); feeding information; breeding information; behavioural information; travel information; preventive medicine information and previous medical information. All variables with a P value of <0.2 in the univariable analysis were considered for possible inclusion in a multivariable model. A final model, produced by a forward stepwise method, identified crib-biting or windsucking, an increasing number of hours spent in a stable, a recent change in a regular exercise programme, the absence of administration of an ivermectin or moxidectin anthelmintic in the previous 12 months and a history of travel in the previous 24 h as associated with a significantly increased risk of SCOD. An alternative final model, produced by a backwards elimination method, identified the same variables as the forward model with, in addition, a history of residing on the current establishment for less than 6 months, a history of a previous colic episode and the fewer times per year the teeth were checked/treated as associated with a significantly increased risk of SCOD. Three of the risk factors in this model were associated with a large increase in risk: stabling for 24 h/day, crib-biting/windsucking and travel in the previous 24 h.

  13. Incorporating Single-Locus Tests into Haplotype Cladistic Analysis in Case-Control Studies

    PubMed Central

    Liu, Jianfeng; Papasian, Chris; Deng, Hong-Wen

    2007-01-01

    In case-control studies, genetic associations for complex diseases may be probed either with single-locus tests or with haplotype-based tests. Although there are different views on the relative merits and preferences of the two test strategies, haplotype-based analyses are generally believed to be more powerful to detect genes with modest effects. However, a main drawback of haplotype-based association tests is the large number of distinct haplotypes, which increases the degrees of freedom for corresponding test statistics and thus reduces the statistical power. To decrease the degrees of freedom and enhance the efficiency and power of haplotype analysis, we propose an improved haplotype clustering method that is based on the haplotype cladistic analysis developed by Durrant et al. In our method, we attempt to combine the strengths of single-locus analysis and haplotype-based analysis into one single test framework. Novel in our method is that we develop a more informative haplotype similarity measurement by using p-values obtained from single-locus association tests to construct a measure of weight, which to some extent incorporates the information of disease outcomes. The weights are then used in computation of similarity measures to construct distance metrics between haplotype pairs in haplotype cladistic analysis. To assess our proposed new method, we performed simulation analyses to compare the relative performances of (1) conventional haplotype-based analysis using original haplotype, (2) single-locus allele-based analysis, (3) original haplotype cladistic analysis (CLADHC) by Durrant et al., and (4) our weighted haplotype cladistic analysis method, under different scenarios. Our weighted cladistic analysis method shows an increased statistical power and robustness, compared with the methods of haplotype cladistic analysis, single-locus test, and the traditional haplotype-based analyses. The real data analyses also show that our proposed method has practical

  14. Predictors of delayed recovery following pediatric sports-related concussion: a case-control study.

    PubMed

    Miller, Joseph H; Gill, Clarence; Kuhn, Elizabeth N; Rocque, Brandon G; Menendez, Joshua Y; O'Neill, Jilian A; Agee, Bonita S; Brown, Steven T; Crowther, Marshall; Davis, R Drew; Ferguson, Drew; Johnston, James M

    2016-04-01

    postconcussive symptoms lasting more than 28 days. For patients without SCAT2 scores, female sex and reporting a history of ADHD significantly increased the odds of prolonged recovery (aOR 4.41, 95% CI 1.93-10.07 and aOR 3.87, 95% CI 1.13-13.24, respectively). Concussions resulting from playing a nonhelmet sport were also associated with a higher risk for prolonged symptoms in patients with and without SCAT2 scores (OR 2.59, 95% CI 1.28-5.26 and OR 2.17, 95% CI 0.99-7.73, respectively). Amnesia, balance abnormalities, and a history of migraines were not associated with symptoms lasting longer than 28 days. CONCLUSIONS This case-control study suggests candidate risk factors for predicting prolonged recovery following sports-related concussion. Large prospective cohort studies of youth athletes examined and treated with standardized protocols will be needed to definitively establish these associations and confirm which children are at highest risk for delayed recovery.

  15. Multicenter Case-Control Study on Restless Legs Syndrome in Multiple Sclerosis: the REMS Study

    PubMed Central

    Manconi, Mauro; Ferini-Strambi, Luigi; Filippi, Massimo; Bonanni, Enrica; Iudice, Alfonso; Murri, Luigi; Gigli, Gian Luigi; Fratticci, Lara; Merlino, Giovanni; Terzano, Giovanni; Granella, Franco; Parrino, Liborio; Silvestri, Rosalia; Aricò, Irene; Dattola, Vincenzo; Russo, Giovanna; Luongo, Carmela; Cicolin, Alessandro; Tribolo, Antonella; Cavalla, Paola; Savarese, Mariantonietta; Trojano, Maria; Ottaviano, Salvatore; Cirignotta, Fabio; Simioni, Valentina; Salvi, Fabrizio; Mondino, Fiorella; Perla, Franco; Chinaglia, Giorgia; Zuliani, Cristina; Cesnik, Edward; Granieri, Enrico; Placidi, Fabio; Palmieri, Maria Giuseppina; Manni, Raffaele; Terzaghi, Michele; Bergamaschi, Roberto; Rocchi, Raffaele; Ulivelli, Monica; Bartalini, Sabina; Ferri, Raffaele; Fermo, Salvatore Lo; Ubiali, Emilio; Viscardi, Massimo; Rottoli, Mariarosa; Nobili, Lino; Protti, Alessandra; Ferrillo, Franco; Allena, Marta; Mancardi, Gianluigi; Guarnieri, Biancamaria; Londrillo, Francesco

    2008-01-01

    Study objectives: To verify the existence of a symptomatic form of restless legs syndrome (RLS) secondary to multiple sclerosis (MS) and to identify possible associated risk factors. Design: Prospective, multicenter, case-control epidemiologic survey. Settings: Twenty sleep centers certified by the Italian Association of Sleep Medicine. Patients: Eight hundred and sixty-one patients affected by MS and 649 control subjects. Interventions: N/A. Measures and results: Data regarding demographic and clinical factors, presence and severity of RLS, the results of hematologic tests, and visual analysis of cerebrospinal magnetic resonance imaging studies were collected. The prevalence of RLS was 19% in MS and 4.2% in control subjects, with a risk to be affected by RLS of 5.4 (95%confidence interval: 3.56–8.26) times greater for patients with MS than for control subjects. In patients with MS, the following risk factors for RLS were significant: older age; longer MS duration; the primary progressive MS form; higher global, pyramidal, and sensory disability; and the presence of leg jerks before sleep onset. Patients with MS and RLS more often had sleep complaints and a higher intake of hypnotic medications than patients with MS without RLS. RLS associated with MS was more severe than that of control subjects. Conclusions: RLS is significantly associated with MS, especially in patients with severe pyramidal and sensory disability. These results strengthen the idea that the inflammatory damage correlated with MS may induce a secondary form of RLS. As it does in idiopathic cases, RLS has a significant impact on sleep quality in patients with MS; therefore, it should be always searched for, particularly in the presence of insomnia unresponsive to treatment with common hypnotic drugs. Citation: Manconi M; Ferini-Strambi L; Filippi M; Bonanni E; Iudice A; Murri L; Gigli GL; Fratticci L; Merlino G; Terzano G; Granella F; Parrino L; Silvestri R; Aricò I; Dattola V; Russo G; Luongo

  16. Design and methods in a multi-center case-control interview study.

    PubMed Central

    Hartge, P; Cahill, J I; West, D; Hauck, M; Austin, D; Silverman, D; Hoover, R

    1984-01-01

    We conducted a case-control study in ten areas of the United States in which a total of 2,982 bladder cancer patients and 5,782 population controls were interviewed. We employed a variety of existing and new techniques to reduce bias and to monitor the quality of data collected. We review here many of the design elements and field methods that can be generally applied in epidemiologic studies, particularly multi-center interview studies, and explain the reasons for our selection of the methods, instruments, and procedures used. PMID:6689843

  17. Challenges in Recruiting Aging Women Holocaust Survivors to a Case Control Study of Breast Cancer.

    PubMed

    Vin-Raviv, Neomi; Dekel, Rachel; Barchana, Micha; Linn, Shai; Keinan-Boker, Lital

    2015-01-01

    Older adults are underrepresented in medical research for many reasons, including recruitment difficulties. Recruitment of older adults for research studies is often a time-consuming process and can be more challenging when the study involves older adults with unique exposures to traumatic events and from minority groups. The current article provides a brief overview of (a) challenges encountered while recruiting aging women Holocaust survivors for a case control study and (b) strategies used for meeting those challenges. The case group comprised women Holocaust survivors who were recently diagnosed with breast cancer and the control group comprised healthy women from a Holocaust-survivor community in Israel.

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

    PubMed Central

    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

  19. Does breast feeding provide protection against acute appendicitis? A case-control study.

    PubMed

    Alves, João Guilherme Bezerra; Figueiroa, José Natal; Barros, Isabela

    2008-10-01

    Breast feeding stimulates a more tolerant lymphoid tissue at the base of the appendix and this could provide protection against acute appendicitis. Two studies reported that children and adolescents with appendicitis were less likely to have been breast fed. In a case-control study of 200 children with histologically confirmed acute appendicitis matched by 200 siblings with the same sex and difference age - up to three-year-old - we found breast feeding in at least the first two months of life and for more than four months provides protection against acute appendicitis. These findings suggesting that breast feeding may possibly give protection against the development of appendicitis.

  20. Risk factors for femicide-suicide in abusive relationships: results from a multisite case control study.

    PubMed

    Koziol-McLain, Jane; Webster, Daniel; McFarlane, Judith; Block, Carolyn Rebecca; Ulrich, Yvonne; Glass, Nancy; Campbell, Jacquelyn C

    2006-02-01

    The killing of women by men who then take their own lives (femicide-suicide) is the most common form of homicide-suicide. This study identified femicide-suicide risk factors in an 11-city case-control study of femicide in the United States. Perpetrator, victim, relationship, and incident characteristics were analyzed for femicide-suicide cases (n = 67) and controls (n = 356, women living in the community with nonfatal physical abuse) using logistic regression modeling. Two risk factors emerged that were unique to femicide-suicides cases compared to overall femicide risk analyses: prior perpetrator suicide threats and victims having ever been married to the perpetrator.

  1. An alternative experimental case-control design for genetic association studies on bovine mastitis.

    PubMed

    Biffani, S; Del Corvo, M; Capoferri, R; Pedretti, A; Luini, M; Williams, J L; Pagnacco, G; Minvielle, F; Minozzi, G

    2017-04-01

    The possibility of using genetic control strategies to increase disease resistance to infectious diseases relies on the identification of markers to include in the breeding plans. Possible incomplete exposure of mastitis-free (control) animals, however, is a major issue to find relevant markers in genetic association studies for infectious diseases. Usually, designs based on elite dairy sires are used in association studies, but an epidemiological case-control strategy, based on cows repeatedly field-tested could be an alternative for disease traits. To test this hypothesis, genetic association results obtained in the present work from a cohort of Italian Holstein cows tested for mastitis over time were compared with those from a previous genome-wide scan on Italian Holstein sires genotyped with 50k single nucleotide polymorphisms for de-regressed estimated breeding values for somatic cell counts (SCCs) on Bos taurus autosome (BTA6) and BTA14. A total of 1121 cows were selected for the case-control approach (cases=550, controls=571), on a combination of herd level of SCC incidence and of within herd individual level of SCC. The association study was conducted on nine previously identified markers, six on BTA6 and four on BTA14, using the R statistical environment with the 'qtscore' function of the GenABEL package, on high/low adjusted linear score as a binomial trait. The results obtained in the cow cohort selected on epidemiological information were in agreement with those obtained from the previous sire genome-wide association study (GWAS). Six out of the nine markers showed significant association, four on BTA14 (rs109146371, rs109234250, rs109421300, rs109162116) and two on BTA6 (rs110527224 and rs42766480). Most importantly, using mastitis as a case study, the current work further validated the alternative use of historical field disease data in case-control designs for genetic analysis of infectious diseases in livestock.

  2. Random and systematic errors in case-control studies calculating the injury risk of driving under the influence of psychoactive substances.

    PubMed

    Houwing, Sjoerd; Hagenzieker, Marjan; Mathijssen, René P M; Legrand, Sara-Ann; Verstraete, Alain G; Hels, Tove; Bernhoft, Inger Marie; Simonsen, Kirsten Wiese; Lillsunde, Pirjo; Favretto, Donata; Ferrara, Santo D; Caplinskiene, Marija; Movig, Kris L L; Brookhuis, Karel A

    2013-03-01

    Between 2006 and 2010, six population based case-control studies were conducted as part of the European research-project DRUID (DRiving Under the Influence of Drugs, alcohol and medicines). The aim of these case-control studies was to calculate odds ratios indicating the relative risk of serious injury in car crashes. The calculated odds ratios in these studies showed large variations, despite the use of uniform guidelines for the study designs. The main objective of the present article is to provide insight into the presence of random and systematic errors in the six DRUID case-control studies. Relevant information was gathered from the DRUID-reports for eleven indicators for errors. The results showed that differences between the odds ratios in the DRUID case-control studies may indeed be (partially) explained by random and systematic errors. Selection bias and errors due to small sample sizes and cell counts were the most frequently observed errors in the six DRUID case-control studies. Therefore, it is recommended that epidemiological studies that assess the risk of psychoactive substances in traffic pay specific attention to avoid these potential sources of random and systematic errors. The list of indicators that was identified in this study is useful both as guidance for systematic reviews and meta-analyses and for future epidemiological studies in the field of driving under the influence to minimize sources of errors already at the start of the study.

  3. Case-control study of high risk occupations for bladder cancer in New Zealand.

    PubMed

    Dryson, Evan; 't Mannetje, Andrea; Walls, Chris; McLean, Dave; McKenzie, Fiona; Maule, Milena; Cheng, Soo; Cunningham, Chris; Kromhout, Hans; Boffetta, Paolo; Blair, Aaron; Pearce, Neil

    2008-03-15

    We conducted a nationwide case-control study of bladder cancer in adult New Zealanders to identify occupations that may contribute to the risk of bladder cancer in the New Zealand population. A total of 213 incident cases of bladder cancer (age 25-70 years) notified to the New Zealand Cancer Registry during 2003 and 2004, and 471 population controls, were interviewed face-to-face. The questionnaire collected demographic information and a full occupational history. The relative risks for bladder cancer associated with ever being employed in particular occupations and industries were calculated by unconditional logistic regression adjusting for age, sex, smoking and socio-economic status. Estimates were subsequently semi-Bayes adjusted to account for the large number of occupations and industries being considered. An elevated bladder cancer risk was observed for hairdressers (odds ratio (OR) 9.15 95% Confidence Interval (95%CI) 1.60-62.22), and sewing machinists (OR 3.07 95%CI 1.35-6.96). Significantly increased risks were not observed for several other occupations that have been reported in previous studies, including sales assistants (OR 1.03 95%CI 0.64-1.67), painters and paperhangers (OR 1.42 95%CI 0.56-3.60), sheet metal workers (OR 0.39, 95%CI 0.15-1.00), printing trades workers (OR 1.11 95%CI 0.41-3.05) and truck drivers (OR 1.36 95%CI 0.60-3.09), although the elevated odds ratios for painters, printers and truck drivers are consistent with excesses observed in other studies. Nonsignificantly increased risks were observed for tailors and dressmakers (OR 2.84 95%CI 0.62-13.05), rubber and plastics products machine operators (OR 2.82 95%CI 0.75-10.67), building workers (OR 2.15, 95%CI 0.68-6.73), and female market farmers and crop growers (OR 2.05 95%CI 0.72-5.83). In conclusion, this study has confirmed that hairdressers and sewing machinists are high risk occupations for bladder cancer in New Zealand, and has identified several other occupations and industries

  4. Bayesian analysis of genetic interactions in case-control studies, with application to adiponectin genes and colorectal cancer risk.

    PubMed

    Yi, Nengjun; Kaklamani, Virginia G; Pasche, Boris

    2011-01-01

    Complex diseases such as cancers are influenced by interacting networks of genetic and environmental factors. However, a joint analysis of multiple genes and environmental factors is challenging, owing to potentially large numbers of correlated and complex variables. We describe Bayesian generalized linear models for simultaneously analyzing covariates, main effects of numerous loci, gene-gene and gene-environment interactions in population case-control studies. Our Bayesian models use Student-t prior distributions with different shrinkage parameters for different types of effects, allowing reliable estimates of main effects and interactions and hence increasing the power for detection of real signals. We implement a fast and stable algorithm for fitting models by extending available tools for classical generalized linear models to the Bayesian case. We propose a novel method to interpret and visualize models with multiple interactions by computing the average predictive probability. Simulations show that the method has the potential to dissect interacting networks of complex diseases. Application of the method to a large case-control study of adiponectin genes and colorectal cancer risk highlights the previous results and detects new epistatic interactions and sex-specific effects that warrant follow-up in independent studies.

  5. Gastric cancer and coal mine dust exposure. A case-control study

    SciTech Connect

    Ames, R.G.

    1983-10-01

    Based on evidence that coal miners have elevated gastric cancer mortality rates, a case-control study was developed to assess the gastric cancer risk of coal mine dust exposure. Forty-six cases of US white male gastric cancer deaths from NIOSH coal miner cohorts were individually matched by age to controls. From these data we show that a statistically elevated gastric cancer risk exists for miners who have prolonged exposure to coal mine dust and prolonged exposure to cigarette smoke. Coal workers' pneumoconiosis, a disease defined in terms of coal dust deposition in the lungs, was not found to be a gastric cancer risk.

  6. Spatial variation in mortality risk for haematological malignancies near a petrochemical refinery: a population-based case-control study

    PubMed Central

    Di Salvo, Francesca; Meneghini, Elisabetta; Vieira, Veronica; Baili, Paolo; Mariottini, Mauro; Baldini, Marco; Micheli, Andrea; Sant, Milena

    2015-01-01

    Introduction The study investigated the geographic variation of mortality risk for hematological malignancies (HMs) in order to identify potential high-risk areas near an Italian petrochemical refinery. Material and methods A population-based case-control study was conducted and residential histories for 171 cases and 338 sex- and age-matched controls were collected. Confounding factors were obtained from interviews with consenting relatives for 109 HM deaths and 267 controls. To produce risk mortality maps, two different approaches were applied. We mapped (1) adptive kernel density relative risk estimation (KDE) for case-control studies which estimates a spatial relative risk function using the ratio between cases and controls’ densities, and (2) estimated odds ratios for case-control study data using generalized additive models (GAMs) to smooth the effect of location, a proxy for exposure, while adjusting for confounding variables. Results No high-risk areas for HM mortality were identified among all subjects (men and women combined), by applying both approaches. Using the adaptive KDE approach, we found a significant increase in death risk only among women in a large area 2–6 km southeast of the refinery and the application of GAMs also identified a similarly-located significant high-risk area among women only (global p-value<0.025). Potential confounding risk factors we considered in the GAM did not alter the results. Conclusion Both approaches identified a high-risk area close to the refinery among women only. Those spatial methods are useful tools for public policy management to determine priority areas for intervention. Our findings suggest several directions for further research in order to identify other potential environmental exposures that may be assessed in forthcoming studies based on detailed exposure modeling. PMID:26073202

  7. [Relations between extraction of wisdom teeth and temporomandibular disorders: a case/control study].

    PubMed

    Duval, Florian; Leroux, Agathe; Bertaud, Valérie; Meary, Fleur; Le Padellec, Clément; Refuveille, Laura; Lemaire, Arnaud; Sorel, Olivier; Chauvel-Lebret, Dominique

    2015-09-01

    The aim of this study was to assess the impact of extraction of third molars on the occurrence of temporo-mandibular disorders (TMD). A review of the literature and a case-control study have been conducted. The case-control study compares the frequency of extraction of third molars between the sample with TMD (case) and the sample without TMD (control). The proportion of patients who had undergone extractions of wisdom teeth was higher in the case group than in the control group. The difference was statistically significant when patients had undergone extraction of all four wisdom teeth or when the extraction of four wisdom teeth underwent in one sitting or under general anesthesia. The study of patients in case sample shows that all signs of TMD were more common in patients who had undergone extractions in several sessions and under local anesthesia. The temporomandibular joint sounds are significantly more frequent with local anesthesia. In the case group, 85 to 92% of patients have parafunctions and 5 to 11% have malocclusion. This demonstrates the multifactorial etiology of temporomandibular disorders.

  8. Diagnostic Microbiologic Methods in the GEMS-1 Case/Control Study

    PubMed Central

    Panchalingam, Sandra; Antonio, Martin; Hossain, Anowar; Mandomando, Inacio; Ochieng, Ben; Oundo, Joseph; Ramamurthy, T.; Tamboura, Boubou; Zaidi, Anita K. M.; Petri, William; Houpt, Eric; Murray, Patrick; Prado, Valeria; Vidal, Roberto; Steele, Duncan; Strockbine, Nancy; Sansonetti, Philippe; Glass, Roger I.; Robins-Browne, Roy M.; Tauschek, Marija; Svennerholm, Ann-Marie; Kotloff, Karen; Levine, Myron M.; Nataro, James P.

    2012-01-01

    To understand the etiology of moderate-to-severe diarrhea among children in high mortality areas of sub-Saharan Africa and South Asia, we performed a comprehensive case/control study of children aged <5 years at 7 sites. Each site employed an identical case/control study design and each utilized a uniform comprehensive set of microbiological assays to identify the likely bacterial, viral and protozoal etiologies. The selected assays effected a balanced consideration of cost, robustness and performance, and all assays were performed at the study sites. Identification of bacterial pathogens employed streamlined conventional bacteriologic biochemical and serological algorithms. Diarrheagenic Escherichia coli were identified by application of a multiplex polymerase chain reaction assay for enterotoxigenic, enteroaggregative, and enteropathogenic E. coli. Rotavirus, adenovirus, Entamoeba histolytica, Giardia enterica, and Cryptosporidium species were detected by commercially available enzyme immunoassays on stool samples. Samples positive for adenovirus were further evaluated for adenovirus serotypes 40 and 41. We developed a novel multiplex assay to detect norovirus (types 1 and 2), astrovirus, and sapovirus. The portfolio of diagnostic assays used in the GEMS study can be broadly applied in developing countries seeking robust cost-effective methods for enteric pathogen detection. PMID:23169941

  9. Leptospira Exposure and Patients with Liver Diseases: A Case-Control Seroprevalence Study

    PubMed Central

    Alvarado-Esquivel, Cosme; Sánchez-Anguiano, Luis Francisco; Hernández-Tinoco, Jesús; Ramos-Nevárez, Agar; Margarita Cerrillo-Soto, Sandra; Alberto Guido-Arreola, Carlos

    2016-01-01

    The seroepidemiology of Leptospira infection in patients suffering from liver disease has been poorly studied. Information about risk factors associated with infection in liver disease patients may help in the optimal planning of preventive measures. We sought to determine the association of Leptospira IgG seroprevalence and patients with liver diseases, and to determine the characteristics of the patients with Leptospira exposure. We performed a case-control study of 75 patients suffering from liver diseases and 150 age- and gender-matched control subjects. Diagnoses of liver disease included liver cirrhosis, steatosis, chronic hepatitis, acute hepatitis, and amoebic liver abscess. Sera of participants were analyzed for the presence of anti- Leptospira IgG antibodies using a commercially available enzyme immunoassay. Anti-Leptospira IgG antibodies were found in 17 (22.7%) of 75 patients and in 15 (10.0%) of 150 control subjects (OR = 2.32; 95% CI: 1.09-4.94; P=0.03). This is the first age- and gender-matched case control study about Leptospira seroprevalence in patients with liver diseases. Results indicate that Leptospira infection is associated with chronic and acute liver diseases. Results warrants for additional studies on the role of Leptospira exposure in chronic liver disease. PMID:27493589

  10. A Case-Control Study of Risk Factors for Salivary Gland Cancer in Canada

    PubMed Central

    de Groh, Margaret; Morrison, Howard

    2017-01-01

    Aim. To assess the effect of various lifestyle risk factors on the risk of salivary gland cancer in Canada using data from a population-based case-control study. Methods. Data from a population-based case-control study of 132 incident cases of salivary gland cancer and 3076 population controls were collected through self-administered questionnaire and analysed using unconditional logistic regression. Results. Four or more servings/week of processed meat product was associated with an adjusted odds ratio (OR) and corresponding 95% confidence interval (CI) of 1.62 (1.02–2.58). Nonsignificantly increased ORs were also related to obesity, >7 drinks/week of alcohol consumption, and occupational exposure to radiation. Furthermore, nonsignificantly decreased ORs were found to be associated with high education level (>12 years) (OR = 0.65), high consumption of spinach/squash (OR = 0.62) and all vegetables/vegetable juices (OR = 0.75), and >30 sessions/month of recreational physical activity (OR = 0.78). Conclusions. This study suggests positive associations with consumption of processed meat, smoking, obesity, alcohol drinking, and occupational exposure to radiation as well as negative associations with higher education, consumption of spinach/squash, and physical activity, which suggest a role of lifestyle factors in the etiology of salivary gland cancer. However, these findings were based on small number of cases and were nonsignificant. Further larger studies are warranted to confirm our findings. PMID:28133481

  11. Diagnostic microbiologic methods in the GEMS-1 case/control study.

    PubMed

    Panchalingam, Sandra; Antonio, Martin; Hossain, Anowar; Mandomando, Inacio; Ochieng, Ben; Oundo, Joseph; Ramamurthy, T; Tamboura, Boubou; Zaidi, Anita K M; Petri, William; Houpt, Eric; Murray, Patrick; Prado, Valeria; Vidal, Roberto; Steele, Duncan; Strockbine, Nancy; Sansonetti, Philippe; Glass, Roger I; Robins-Browne, Roy M; Tauschek, Marija; Svennerholm, Ann-Marie; Berkeley, Lynette Y; Kotloff, Karen; Levine, Myron M; Nataro, James P

    2012-12-01

    To understand the etiology of moderate-to-severe diarrhea among children in high mortality areas of sub-Saharan Africa and South Asia, we performed a comprehensive case/control study of children aged <5 years at 7 sites. Each site employed an identical case/control study design and each utilized a uniform comprehensive set of microbiological assays to identify the likely bacterial, viral and protozoal etiologies. The selected assays effected a balanced consideration of cost, robustness and performance, and all assays were performed at the study sites. Identification of bacterial pathogens employed streamlined conventional bacteriologic biochemical and serological algorithms. Diarrheagenic Escherichia coli were identified by application of a multiplex polymerase chain reaction assay for enterotoxigenic, enteroaggregative, and enteropathogenic E. coli. Rotavirus, adenovirus, Entamoeba histolytica, Giardia enterica, and Cryptosporidium species were detected by commercially available enzyme immunoassays on stool samples. Samples positive for adenovirus were further evaluated for adenovirus serotypes 40 and 41. We developed a novel multiplex assay to detect norovirus (types 1 and 2), astrovirus, and sapovirus. The portfolio of diagnostic assays used in the GEMS study can be broadly applied in developing countries seeking robust cost-effective methods for enteric pathogen detection.

  12. A multicenter, matched case-control study of risk factors for equine laminitis.

    PubMed

    Alford, P; Geller, S; Richrdson, B; Slater, M; Honnas, C; Foreman, J; Robinson, J; Messer, M; Roberts, M; Goble, D; Hood, D; Chaffin, M

    2001-05-01

    Risk factors for equine laminitis were examined in a prospective case-control study of the 258 cases seen at six collaborating veterinary teaching hospitals over a 32-month period. Case-control pairs were matched on institution, clinician, and season of diagnosis. The 90% of case-control pairs (78 acute, 155 chronic) that had complete data for age, gender, and breed were used in separate conditional logistic-regression models for acute and chronic laminitis. There was an increase in risk for horses with acute laminitis from 5 to 7 years of age (OR 4.7, 95% CI 1.3-16) and from 13 to 31 years of age (OR 3.9, 95% CI 1.3-12) (both compared to <5 years); risk was increased for chronic laminitis from 10 to 14 years (OR 3, 95% CI 1.4-6.8) and from 15 to 38 years (OR 2.9, 95% CI 1.4-6.1) (both compared to <6 years). Mares - but not stallions - were more likely than geldings to develop acute laminitis (OR 2.6, 95% CI 1.1-6.2) and chronic laminitis (OR 2.0, 95% CI 1.1-3.6). In the small acute-laminitis data set, the breed variable was collapsed into three categories: Thoroughbred (THB, reference), the Quarter Horse (QH), and other (non-QH-THB). The non-QH-THB group was at increased risk of acute laminitis (OR 3.8, 95% CI 1.2-11.8). For the seven breed-group categories used in the chronic-laminitis model, however, all non-THB breed groups appeared significantly at risk as compared to the THB, with odds ratios ranging from 3.3 (95% CI 1.3-8.30) for the QH to 9.1 (95% CI 2.1-39.3) for ponies.

  13. Exposure to electromagnetic fields and suicide among electric utility workers: a nested case-control study

    PubMed Central

    van Wijngaarden, E.; Savitz, D.; Kleckner, R.; Cai, J.; Loomis, D.

    2000-01-01

    OBJECTIVES—This nested case-control study examines mortality from suicide in relation to estimated exposure to extremely low frequency electromagnetic fields (EMFs) in a cohort of 138 905 male electric utility workers.
METHODS—Case-control sampling included 536 deaths from suicide and 5348 eligible controls. Exposure was classified based on work in the most common jobs with increased exposure to magnetic fields and indices of cumulative exposure to magnetic fields based on a measurement survey.
RESULTS—Suicide mortality was increased relative to work in exposed jobs and with indices of exposure to magnetic fields. Increased odds ratios (ORs) were found for years of employment as an electrician (OR 2.18; 95% confidence interval (95% CI) 1.25 to 3.80) or lineman (OR 1.59; 95% CI 1.18 to 2.14), whereas a decreased OR was found for power plant operators (OR 0.67; 95% CI 0.33 to 1.40). A dose response gradient with exposure to magnetic fields was found for exposure in the previous year, with a mortality OR of 1.70 (95% CI 1.00 to 2.90) in the highest exposure category. Stronger associations, with ORs in the range of 2.12-3.62, were found for men <50 years of age.
CONCLUSION—These data provide evidence for an association between occupational electromagnetic fields and suicide that warrants further evaluation. A plausible mechanism related to melatonin and depression provides a direction for additional laboratory research as well as epidemiological evaluation.


Keywords: electromagnetic fields; suicide; nested case-control PMID:10810112

  14. A case-control study of gastric cancer and diet in Italy.

    PubMed

    Buiatti, E; Palli, D; Decarli, A; Amadori, D; Avellini, C; Bianchi, S; Biserni, R; Cipriani, F; Cocco, P; Giacosa, A

    1989-10-15

    A case-control study was conducted in high- and low-risk areas of Italy to evaluate reasons for the striking geographic variation in gastric cancer (GC) mortality within the country. Personal interviews with 1,016 histologically confirmed GC cases and 1,159 population controls of similar age and sex revealed that the patients were more often of lower social class and resident in rural areas and more frequently reported a familial history of gastric (but not other) cancer. After adjusting for these effects, case-control differences were found for several dietary variables, assessed by asking about the usual frequency of consumption of 146 food items and beverages. A significant trend of increasing GC risk was found with increasing consumption of traditional soups, meat, salted/dried fish and a combination of cold cuts and seasoned cheeses. The habit of adding salt and the preference for salty foods were associated with elevated GC risk, while more frequently storing foods in the refrigerator, the availability of a freezer and use of frozen foods lowered risk. Reduced GC risk were associated with increasing intake of raw vegetables, fresh fruit and citrus fruits. Lowered risk was also related to consumption of spices, olive oil and garlic. Neither cigarette smoking nor alcoholic beverage drinking were significantly related to GC risk. The case-control differences tended to be consistent across geographic areas, despite marked regional variations in intake levels of certain foods. The high-risk areas tended to show higher consumption of food associated with elevated risk (traditional soups, cold cuts) and lower consumption of foods associated with reduced risks (raw vegetables, citrus fruits, garlic). Our findings indicate that dietary factors contribute to the regional variation of stomach cancer occurrence in Italy, and offer clues for further etiologic and prevention research.

  15. Severity of Scorpion Stings in the Western Brazilian Amazon: A Case-Control Study

    PubMed Central

    Queiroz, Amanda M.; Sampaio, Vanderson S.; Mendonça, Iran; Fé, Nelson F.; Sachett, Jacqueline; Ferreira, Luiz Carlos L.; Feitosa, Esaú; Wen, Fan Hui; Lacerda, Marcus; Monteiro, Wuelton

    2015-01-01

    Background Scorpion stings are a major public health problem in Brazil, with an increasing number of registered cases every year. Affecting mostly vulnerable populations, the phenomenon is not well described and is considered a neglected disease. In Brazil, the use of anti-venom formulations is provided free of charge. The associate scorpion sting case is subject to compulsory reporting. This paper describes the epidemiology and identifies factors associated with severity of scorpions stings in the state of Amazonas, in the Western Brazilian Amazon. Methodology/Principal Findings This study included all cases of scorpion stings in the state of Amazonas reported to the Brazilian Diseases Surveillance System from January 1, 2007 to December 31, 2014. A case-control study was conducted to identify factors associated with scorpions sting severity. A total of 2,120 cases were reported during this period. The mean incidence rate in the Amazonas was 7.6 per 100,000 inhabitants/year. Scorpion stings showed a large spatial distribution in the state and represent a potential occupational health problem for rural populations. There was a positive correlation between the absolute number of cases and the altimetric river levels in the Central (p<0.001; Rs = 0.479 linear) and Southwest (p = 0.032; linear Rs = 0.261) regions of the state. Cases were mostly classified as mild (68.6%), followed by moderate (26.8%), and severe (4.6%). The overall lethality rate was 0.3%. Lethality rate among children ≤10 years was 1.3%. Age <10 years [OR = 2.58 (95%CI = 1.47–4.55; p = 0.001)], stings occurring in the rural area [OR = 1.97 (95%CI = 1.18–3.29; p = 0.033) and in the South region of the state [OR = 1.85 (95%CI = 1.17–2.93; p = 0.008)] were independently associated with the risk of developing severity. Conclusions/Significance Scorpion stings show an extensive distribution in the Western Brazilian Amazon threatening especially rural populations, children ≤10 in particular. Thus

  16. Assessing risk factors of sporadic Campylobacter infection: a case-control study in Arizona.

    PubMed

    Pogreba-Brown, K; Baker, A; Ernst, K; Stewart, J; Harris, R B; Weiss, J

    2016-03-01

    Case-control studies of sporadic Campylobacter infections have predominately been conducted in non-Hispanic populations. In Arizona, rates of campylobacteriosis have been historically higher than the national average, with particularly high rates in Hispanics. In 2010, health departments and a state university collaborated to conduct a statewide case-control study to determine whether risk factors differ in an ethnically diverse region of the United States. Statistically significant risk factors in the final multivariate model were: eating cantaloupe [odds ratio (OR) 7·64], handling raw poultry (OR 4·88) and eating queso fresco (OR 7·11). In addition, compared to non-Hispanic/non-travellers, the highest risk group were Hispanic/non-travellers (OR 7·27), and Hispanic/travellers (OR 5·87, not significant). Results of this study suggest Hispanics have higher odds of disease, probably due to differential exposures. In addition to common risk factors, consumption of cantaloupe was identified as a significant risk factor. These results will inform public health officials of the varying risk factors for Campylobacter in this region.

  17. Control selection methods in recent case-control studies conducted as part of infectious disease outbreaks.

    PubMed

    Waldram, Alison; McKerr, Caoimhe; Gobin, Maya; Adak, Goutam; Stuart, James M; Cleary, Paul

    2015-06-01

    Successful investigation of national outbreaks of communicable disease relies on rapid identification of the source. Case-control methodologies are commonly used to achieve this. We assessed control selection methods used in recently published case-control studies for methodological and resource issues to determine if a standard approach could be identified. Neighbourhood controls were the most frequently used method in 53 studies of a range of different sizes, infections and settings. The most commonly used method of data collection was face to face interview. Control selection issues were identified in four areas: method of identification of controls, appropriateness of controls, ease of recruitment of controls, and resource requirements. Potential biases arising from the method of control selection were identified in half of the studies assessed. There is a need to develop new ways of selecting controls in a rapid, random and representative manner to improve the accuracy and timeliness of epidemiological investigations and maximise the effectiveness of public health interventions. Innovative methods such as prior recruitment of controls could improve timeliness and representativeness of control selection.

  18. A case-control study on risk factors for unintentional childhood poisoning in Tehran

    PubMed Central

    Mansori, Kamyar; Soori, Hamid; Farnaghi, Fariba; Khodakarim, Sohila; Mansouri hanis, Shiva; Khodadost, Mahmoud

    2016-01-01

    Background: Poisoning is a major public health problem and is one of the most frequent causes of emergency hospital admissions. The aim of this study was to identify the main risk factors for unintentional childhood poisoning in Tehran, Iran and to suggest possible causes and preventative measures. Methods: In this case-control study (case, n=140; control, n=280), two controls were selected for every case. Controls were matched by age, sex, and date of hospital attendance. All children and their guardians were then interviewed by the same person using a standard questionnaire that covered the demographic, behavioral, and risk factors associated with accidental poisonings. Results: The most common type of poisoning was related to narcotics (58.6%); and among the narcotics, methadone was the most prevalent poisoning agent (74.7%). Multivariate conditional logistic regression model revealed that addiction in the family (OR=14.6; 95% CI:6.2-34.6), previous poisoning (OR=7; 95% CI:2.4- 20.2), maternal occupation (OR=4; 95% CI:1.3- 12.3), and inaccessibility of poisoning products (OR=0.03; 95% CI:0.01- 0.12) were the main risk factors in unintentional childhood poisoning. Conclusion: Addiction in the family as a risk factor and inaccessibility of poisoning products as a protecting factor were recognized to have the highest correlation with the unintentional child poisoning. These two factors were considered as priorities in health education programs. PMID:27453885

  19. Bronchodilator treatment and asthma death: a new analysis of a British case-control study.

    PubMed

    Butland, Barbara K; Anderson, H Ross; Cates, Christopher J

    2011-04-01

    We investigated the relationship between asthma mortality and long-acting beta(2)-agonists (LABA), including interactions with age, inhaled corticosteroids (ICS) and social deprivation. We used a new, expanded dataset of recorded medication extracted blind from the anonymised primary care records of an earlier British case-control study. The cases were 532 asthma deaths aged < 65 occurring between 1994 and 1998 and the controls were 532 asthma admissions, matched for age, hospital, and index date (date of death/asthma admission). The exposure periods prior to the index date were current (≤ 2 months) or recent ( > 2-6 months). We found no evidence of an overall association with current (OR = 0.89 [95% confidence interval 0.61-1.30]) or recent (1.08 [0.76-1.53]) mention of LABA, but there was some evidence of a positive interaction with age. Among controls with mention of LABA, a concurrent mention of ICS (within 1 month) was common (85% and 93% for the two respective periods) which limited our power to investigate any interaction between LABA and ICS. There was no coherent evidence of effect modification by social deprivation. In a population based case-control study where prescription of LABA without concomitant ICS was uncommon there was no evidence of an overall association between LABA and asthma death.

  20. Case-control study of vulvar vestibulitis risk associated with genital infections.

    PubMed Central

    Smith, Elaine M; Ritchie, Justine M; Galask, Rudolph; Pugh, Erica E; Jia, Jian; Ricks-McGillan, Joan

    2002-01-01

    OBJECTIVE: To evaluate the risk of vulvar vestibulitis syndrome (VVS) associated with genital infections in a case-control study. METHODS: Diagnosed cases with VVS (n = 69) and age-frequency-matched healthy controls (n = 65) were enrolled from gynecology clinics in a university medical hospital during 1999. They were compared for potential risk factors and symptoms of disease. RESULTS: VVS cases had a significantly higher risk of physician-reported bacterial vaginosis (BV) (odds ratio, OR = 9.4), Candida albicans (OR = 5.7), pelvic inflammatory disease (PID) (OR = 11.2), trichomoniasis (OR = 20.6), and vulvar dysplasia (OR = l5.7) but no risk associated with human papillomavirus (HPV), ASCUS, cervical dysplasia, genital warts, chlamydia, genital herpes or gonorrhea. Genital symptoms reported significantly more often with VVS included vulvar burning (91 vs. 12%), dyspareunia (81 vs. 15%), vulvar itching (68 vs. 23%) and dysuria (54 vs. 19%) (p < 0.0001). CONCLUSION: A history of genital infections is associated with an increased risk of VVS. Long-term follow-up case-control studies are needed to elucidate etiologic mechanisms, methods for prevention and effective treatment. PMID:12648313

  1. Stillbirths at Term: Case Control Study of Risk Factors, Growth Status and Placental Histology

    PubMed Central

    Mecacci, Federico; Serena, Caterina; Avagliano, Laura; Cozzolino, Mauro; Baroni, Eleonora; Rambaldi, Marianna Pina; Simeone, Serena; Castiglione, Francesca; Taddei, Gian Luigi; Bulfamante, Gaetano

    2016-01-01

    Objective To investigate the proportion of stillbirths at term associated with abnormal growth using customized birth weight percentiles and to compare histological placental findings both in underweight stillborn fetuses and in live births. Methods A retrospective case-control study of 150 singleton term stillbirths. The livebirth control groups included 586 cases of low-risk pregnancies and 153 late fetal growth restriction fetuses. Stillbirths and livebirths from low-risk pregnancies were classified using customized standards for fetal weight at birth, as adequate for gestational age (AGA; 10-90th percentile), small (SGA; <10th percentile) or large for gestational age (LGA; >90th percentile). Placental characteristics in stillbirth were compared with those from livebirths using four categories: inflammation, disruptive, obstructive and adaptive lesions. Results There was a higher rate of SGA (26% vs 6%, p<0.001) and LGA fetuses (10.6% vs 5.6%, p<0.05) in the stillbirth group. Among stillbirth fetuses, almost half of the SGA were very low birthweight (≤3°percentile) (12% vs 0.3%, p<0.001). The disruptive (7.3% vs 0.17%;p<0.001), obstructive (54.6% vs 7.5%;p<0.001) and adaptive (46.6% vs 35.8%;p<0.001) findings were significantly more common in than in livebirth-low risk. Placental characteristics of AGA and SGA stillbirth were compared with those of AGA and FGR livebirth. In stillbirths-SGA we found a higher number of disruptive (12.8% vs 0%; p<0.001), obstructive (58.9% vs 23.5%;p<0.001) and adaptive lesions (56.4% vs 49%; p 0.47) than in livebirth-FGR. Conclusion The assessment of fetal weight with customized curves can identify fetuses which have not reached their genetically determined growth potential and are therefore at risk for adverse outcomes. Placental evaluation in stillbirths can reveal chronic histological signs that might be useful to clinical assessment, especially in underweight fetuses. PMID:27936018

  2. A case--control study of selenium in nails and prostate cancer risk in British men.

    PubMed

    Allen, N E; Morris, J S; Ngwenyama, R A; Key, T J

    2004-04-05

    In view of the experimental evidence suggesting that the micronutrient selenium reduces prostate cancer risk, we investigated the association between the selenium level in fingernails, a measure of long-term selenium intake, and prostate cancer risk in a case-control study among 656 British men, conducted in 1989-1992. Nail clippings were taken at the time of recruitment and selenium concentration, measured using neutron activation techniques, was successfully assayed for 300 case-control pairs and varied six-fold among the controls (0.59 p.p.m.; interquartile range, 0.50-0.71 p.p.m.). Nail selenium concentration was not significantly associated with prostate cancer risk: men in the highest quartile of nail selenium had a slightly increased risk compared with men in the lowest quartile (OR 1.24, 95 CI, 0.73-2.10); for advanced prostate cancer, men in the highest quartile had a slightly reduced risk compared with men in the lowest quartile (OR 0.78, 95% CI, 0.27-2.25). These results suggest that selenium is not strongly associated with prostate cancer risk in British men.

  3. Length of Menstrual Cycle and Risk of Endometriosis: A Meta-Analysis of 11 Case-Control Studies.

    PubMed

    Wei, Ming; Cheng, Yanfei; Bu, Huaien; Zhao, Ye; Zhao, Wenli

    2016-03-01

    Endometriosis is a complex disease that affects a large number of women worldwide and may cause pain and infertility. To systematically review published studies evaluating the relationship between menstrual cycle length and risk of endometriosis. We searched the Cochrane Library, PubMed, Web of Science, and EMBASE in databases in July 2014 using the keywords "case-control studies," "epidemiologic determinants," "risk factors," "menstrual cycle," "menstrual length," "menstrual character," and "endometriosis." We included case-control studies published in English that investigated cases of surgically confirmed endometriosis and examined the relationship between endometriosis risk and menstrual cycle. Eleven articles that met the inclusion criteria included data of 3392 women with endometriosis and 5006 controls. Fixed-effects and random-effects models were used for the evaluation. For the association of risk of endometriosis and menstrual cycle length shorter than or equal to 27 days (SEQ27) or length longer than or equal to 29 days (LEQ29), the odds ratio was 1.22 (95% confidence interval [CI]: 1.05-1.43) and 0.68 (95% CI: 0.48-0.96), respectively. In conclusion, this meta-analysis suggests that menstrual cycle length SEQ27 increase the risk of endometriosis and cycle length LEQ29 decrease the risk.

  4. Zinc Intake and Risk of Prostate Cancer: Case-Control Study and Meta-Analysis

    PubMed Central

    Dabbous, Firas; Ali, Mohamed M.; Batai, Ken; Shah, Ebony; Kittles, Rick A.

    2016-01-01

    Zinc is an essential dietary element that has been implicated in the pathogenesis of prostate cancer, a cancer that disproportionately affects men of African descent. Studies assessing the association of zinc intake and prostate cancer have yielded inconsistent results. Furthermore, very little is known about the relationship between zinc intake and prostate cancer among African Americans. We examined the association between self-reported zinc intake and prostate cancer in a hospital-based case-control study of African Americans. We then compared our results with previous studies by performing a meta-analysis to summarize the evidence regarding the association between zinc and prostate cancer. Newly diagnosed African American men with histologically confirmed prostate cancer (n = 127) and controls (n = 81) were recruited from an urban academic urology clinic in Washington, DC. Controls had higher zinc intake, with a mean of 14 mg/day versus 11 mg/day for cases. We observed a non-significant, non-linear increase in prostate cancer when comparing tertiles of zinc intake (OR <6.5 vs 6.5–12.5mg/day 1.8, 95% CI: 0.6,5.6; OR <6.5 vs >12.5mg/day 1.3, 95% CI: 0.2,6.5). The pooled estimate from 17 studies (including 3 cohorts, 2 nested case-control, 11 case-control studies, and 1 randomized clinical trial, with a total of 111,199 participants and 11,689 cases of prostate cancer) was 1.07hi vs lo 95% CI: 0.98–1.16. Using a dose-response meta-analysis, we observed a non-linear trend in the relationship between zinc intake and prostate cancer (p for nonlinearity = 0.0022). This is the first study to examine the relationship between zinc intake in black men and risk of prostate cancer and systematically evaluate available epidemiologic evidence about the magnitude of the relationship between zinc intake and prostate cancer. Despite of the lower intake of zinc by prostate cancer patients, our meta-analysis indicated that there is no evidence for an association between zinc

  5. Association between Myocardial Infarction and Periodontitis: A Meta-Analysis of Case-Control Studies.

    PubMed

    Shi, Quan; Zhang, Bin; Huo, Na; Cai, Chuan; Liu, Hongchen; Xu, Juan

    2016-01-01

    Background 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.

  6. Case-control studies of sporadic cryptosporidiosis in Melbourne and Adelaide, Australia.

    PubMed Central

    Robertson, B.; Sinclair, M. I.; Forbes, A. B.; Veitch, M.; Kirk, M.; Cunliffe, D.; Willis, J.; Fairley, C. K.

    2002-01-01

    Few studies have assessed risk factors for sporadic cryptosporidiosis in industrialized countries, even though it may be numerically more common than outbreaks of disease. We carried out case-control studies assessing risk factors for sporadic disease in Melbourne and Adelaide, which have water supplies from different ends of the raw water spectrum. In addition to examining drinking water, we assessed several other exposures. 201 cases and 795 controls were recruited for Melbourne and 134 cases and 536 controls were recruited for Adelaide. Risk factors were similar for the two cities, with swimming in public pools and contact with a person with diarrhoea being most important. The consumption of plain tap water was not found to be associated with disease. This study emphasizes the need for regular public health messages to the public and swimming pool managers in an attempt to prevent sporadic cryptosporidiosis, as well as outbreaks of disease. PMID:12113486

  7. Culture, risk factors and suicide in rural China: a psychological autopsy case control study

    PubMed Central

    Zhang, J.; Conwell, Y.; Zhou, L.; Jiang, C.

    2009-01-01

    Objective Previous research on sociocultural factors for Chinese suicide have been basically limited to single case studies or qualitative research with ethnographic methodology. The current study examines the major risk factors and some cultural uniqueness related to Chinese rural suicide using a quantitative design. Method This is a case control study with 66 completed suicides and 66 living controls obtained from psychological autopsy interviews in rural China. Results Both bivariate analyses and the multiple regression model have found that the Chinese rural suicide patterns are basically similar to those in most other cultures in the world: strong predictors of rural Chinese suicide are the psychopathological, psychological, and physical health variables, followed by social support and negative and stressful life events. Other significant correlates include lower education, poverty, religion, and family disputes. Conclusion Culture has an important impact on suicide patterns in a society. PMID:15521827

  8. Adherence to Buprenorphine Maintenance Treatment in Opioid Dependence Syndrome: A Case Control Study

    PubMed Central

    Bandawar, Mrunal; Kandasamy, Arun; Chand, Prabhat; Murthy, Pratima; Benegal, Vivek

    2015-01-01

    Background: Opioid Use disorders are emerging as a serious public health concern in India. Opioid substitution treatment is one of the emerging forms of treatment in this population which needs more evidence to increase its availability and address prejudices towards the same. Materials and Methods: This is a case control study with retrospective design reviewing the charts of patients with opioid dependence syndrome registered between January 2005 to December 2012. Adherence to treatment was the outcome variable assessed in this study. Results: The odds of the Buprenorphine Maintenance Treatment (BMT) group remaining in treatment is 4.5 (P < 0.005) times more than Naltrexone Maintenance Treatment (NMT) group and 7 times (P < 0.001) more than Psychosocial intervention (PST) alone group. Discussion: We believe that these study findings will help in reducing the prejudice towards BMT and encourage further research in this field. Conclusion: BMT has a better adherence rate than other treatments in opioid use disorders. PMID:26664083

  9. Opioid system genes in alcoholism: a case-control study in Croatian population.

    PubMed

    Cupic, B; Stefulj, J; Zapletal, E; Matosic, A; Bordukalo-Niksic, T; Cicin-Sain, L; Gabrilovac, J

    2013-10-01

    Due to their involvement in dependence pathways, opioid system genes represent strong candidates for association studies investigating alcoholism. In this study, single nucleotide polymorphisms within the genes for mu (OPRM1) and kappa (OPRK1) opioid receptors and precursors of their ligands - proopiomelanocortin (POMC), coding for beta-endorphin and prodynorphin (PDYN) coding for dynorphins, were analyzed in a case-control study that included 354 male alcohol-dependent and 357 male control subjects from Croatian population. Analysis of allele and genotype frequencies of the selected polymorphisms of the genes OPRM1/POMC and OPRK1/PDYN revealed no differences between the tested groups. The same was true when alcohol-dependent persons were subdivided according to the Cloninger's criteria into type-1 and type-2 groups, known to differ in the extent of genetic control. Thus, the data obtained suggest no association of the selected polymorphisms of the genes OPRM1/POMC and OPRK1/PDYN with alcoholism in Croatian population.

  10. Dietary factors and the risk of glioma in adults: results of a case-control study in Melbourne, Australia.

    PubMed

    Giles, G G; McNeil, J J; Donnan, G; Webley, C; Staples, M P; Ireland, P D; Hurley, S F; Salzberg, M

    1994-11-01

    In a population-based case-control study of 416 incident gliomas in adults carried out in Melbourne, Australia, between 1987 and 1991, 409 age-sex-matched case-control pairs (243 male and 166 female) had adequate data available to examine associations between the dietary intake of N-nitroso compounds, N-nitroso precursors, other nutrients including N-nitroso inhibitors, and the risk of glioma. Dietary intakes were based on the reported frequency of consumption of 59 food items. Increased odds ratio (OR) were observed in males who consumed high levels of bacon, corned meats, apples, melons and oil. OR less than unity were observed in men consuming cabbage and cola drinks, and in women who consumed wholegrain bread, pasta, corned meat, bananas, cauliflower, brocoli, cola drinks and nuts. Generally, N-nitroso associations were greater in men and micronutrient associations were greater in women. Elevated OR in men, but not women, were associated with the intake of N-nitroso dimethylamine (NDMA), retinol and vitamin E. The intake of nitrate (largely of vegetable origin) was protective in women but not in men. When analyzed using multiple logistic regression, the association with NDMA intake in males was not modified by dietary micronutrient intakes. In females, beta carotene alone, though not directly associated with risk, modified the effect of NDMA. On balance, this study added only limited support to the N-nitroso hypothesis of glial carcinogenesis.

  11. Influence of social factors on avoidable mortality: a hospital-based case-control study.

    PubMed Central

    Bautista, Daniel; Alfonso, José Luis; Corella, Dolores; Saiz, Carmen

    2005-01-01

    OBJECTIVE: The effect of socioeconomic factors on avoidable mortality at an individual level is not well known, since most studies showing this association are based on aggregate data. The purpose of this study was to determine socioeconomic differences between those patients who die of avoidable causes and those who do not die. METHODS: A matched case-control study was carried out regarding in-hospital avoidable mortality (Holland's medical care indicators) that occurred in a university hospital serving a Spanish-Mediterranean population during a 30-month period. RESULTS: We studied 82 cases of death from avoidable causes and 300 controls matched on medical care indicators and age. The variables that showed a statistically significant association with in-hospital avoidable mortality were number of diagnoses (the greater the number, the higher the risk), length of stay (patients staying seven or more days presented a lower risk), and education. Those patients with low and middle educational levels showed a greater risk of avoidable mortality (adjusted odds ratio=3.57 and 2.82, respectively) than those patients with higher levels of education. CONCLUSIONS: Consistent with the findings of studies based on aggregate data, our case-control analyses indicated that among several socioeconomic variables studied, educational level was significantly associated with the risk of in-hospital avoidable mortality, regardless of age and medical care indicators. Patients with low levels of education (<6 years of schooling) were at highest risk for in-hospital avoidable mortality, followed by those with middle levels of education (7-10 years of schooling). PMID:15736332

  12. High Seroprevalence of Leptospira Exposure in Meat Workers in Northern Mexico: A Case-Control Study

    PubMed Central

    Alvarado-Esquivel, Cosme; Hernandez-Tinoco, Jesus; Sanchez-Anguiano, Luis Francisco; Ramos-Nevarez, Agar; Cerrillo-Soto, Sandra Margarita; Saenz-Soto, Leandro; Martinez-Ramirez, Lucio

    2016-01-01

    Background The seroepidemiology of Leptospira infection in workers occupationally exposed to raw meat has been poorly studied. This work aimed to determine the association between Leptospira exposure and the occupation of meat worker, and to determine the seroprevalence association with socio-demographic, work, clinical and behavioral characteristics of the meat workers studied. Methods We performed a case-control study in 124 meat workers and 124 age- and gender-matched control subjects in Durango City, Mexico. Sera of cases and controls were analyzed for anti-Leptospira IgG antibodies using a commercially available enzyme immunoassay. Data of meat workers were obtained with the aid of a questionnaire. The association of Leptospira exposure with the characteristics of meat workers was analyzed by bivariate and multivariate analyses. Results Anti-Leptospira IgG antibodies were found in 22 (17.7%) of 124 meat workers and in eight (6.5%) of 124 controls (OR = 3.12; 95% CI: 1.33 - 7.33; P = 0.006). Seroprevalence of Leptospira infection was similar between male butchers (17.6%) and female butchers (18.2%) (P = 1.00). Multivariate analysis of socio-demographic, work and behavioral variables showed that Leptospira exposure was associated with duration in the activity, rural residence, and consumption of snake meat and unwashed raw fruits. Conclusions This is the first case-control study of the association of Leptospira exposure with the occupation of meat worker. Results indicate that meat workers represent a risk group for Leptospira exposure. Risk factors for Leptospira exposure found in this study may help in the design of optimal preventive measures against Leptospira infection. PMID:26858797

  13. Putative risk factors in developmental dyslexia: a case-control study of Italian children.

    PubMed

    Mascheretti, Sara; Marino, Cecilia; Simone, Daniela; Quadrelli, Ermanno; Riva, Valentina; Cellino, Maria Rosaria; Maziade, Michel; Brombin, Chiara; Battaglia, Marco

    2015-01-01

    Although dyslexia runs in families, several putative risk factors that cannot be immediately identified as genetic predict reading disability. Published studies analyzed one or a few risk factors at a time, with relatively inconsistent results. To assess the contribution of several putative risk factors to the development of dyslexia, we conducted a case-control study of 403 Italian children, 155 with dyslexia, by implementing a stepwise logistic regression applied to the entire sample, and then to boys and girls separately. Younger parental age at child's birth, lower parental education, and risk of miscarriage significantly increased the odds of belonging to the dyslexia group (19.5% of the variation). These associations were confirmed in the analyses conducted separately by sex, except for parental education, which significantly affected only males. These findings support reading disabilities as a multifactorial disorder and may bear some importance for the prevention and/or early detection of children at heightened risk for dyslexia.

  14. Occupation and thyroid cancer: a population-based case-control study in Connecticut

    PubMed Central

    Ba, Yue; Huang, Huang; Lerro, Catherine C.; Li, Shuzhen; Zhao, Nan; Li, Anqi; Ma, Shuangge; Udelsman, Robert; Zhang, Yawei

    2016-01-01

    Objective The study aims to explore the associations between various occupations and thyroid cancer risk. Methods A population-based case-control study involving 462 histologically confirmed incident cases and 498 controls was conducted in Connecticut in 2010–2011. Results A significantly increased risk of thyroid cancer, particularly papillary microcarcinoma, was observed for those working as the healthcare practitioners and technical workers, health diagnosing and treating practitioners and registered nurses. Those working in building and grounds cleaning, maintenance occupations, pest control, retail sales, and customer service also had increased risk for papillary thyroid cancer. Subjects who worked as cooks, janitors, cleaners, and customer service representatives were at an increased risk of papillary thyroid cancer with tumor size >1 cm. Conclusions Certain occupations were associated with an increased risk of thyroid cancer, with some tumor size and subtype specificity. PMID:26949881

  15. [Voice disorders related to job stress in teaching: a case-control study].

    PubMed

    Giannini, Susana Pimentel Pinto; Latorre, Maria do Rosário Dias de Oliveira; Ferreira, Leslie Piccolotto

    2012-11-01

    This case-control study aimed to test the association between voice disorders and job stress among public schoolteachers in São Paulo, Brazil. The groups consisted of teachers with (n = 165) and without (n = 105) voice-related complaints. Both groups answered the questionnaires Conditions of Vocal Production and Job Stress Scale. Analysis of cases and controls showed comparable samples, differing only by vocal symptoms. There was a statistically significant difference between cases and controls in relation to job stress involving high strain (OR = 2.1; 95%CI: 1.1-3.9), which places high demands combined with low job control. High strain in cases in this study represents the highest risk of physical and mental disorders for teachers. Loss of voice prevents teachers from continuing in their professional role, eliminates their professional identity, and jeopardizes their career.

  16. Tobacco chewing and risk of gastric cancer: a case-control study in Yemen.

    PubMed

    Al-Qadasi, F A; Shah, S A; Ghazi, H F

    2017-01-23

    This study aimed to assess the risk factors for gastric cancer in Yemen. A hospital-based case-control study of 70 cases and 140 controls was carried out in Sana'a city between May and October 2014. A structured questionnaire was used to collect information through direct interview. Living in rural areas, tobacco chewing and drinking untreated water were significant risk factors for gastric cancer. Frequent consumption of chicken, cheese, milk, starchy vegetables, cucumber, carrots, leeks, sweet pepper, fruit drinks, legumes and olive oil were associated significantly with decreased risk of gastric cancer. Multiple logistic regression analysis showed that chewing tobacco and frequent consumption of white bread were associated with increased risk of gastric cancer, whereas frequent consumption of chicken, cooked potatoes and fruit drinks had an inverse association. Risk of gastric cancer can be prevented by health education and increasing community awareness.

  17. Dietary total antioxidant capacity and the risk of breast cancer: a case-control study.

    PubMed

    Karimi, Z; Bahadoran, Z; Abedini, S; Houshyar-Rad, A; Rashidkhani, B

    2015-09-28

    There is growing evidence that dietary antioxidants may have favourable effects in reducing cancer risk. In a case-control study we investigated the association of dietary total antioxidant capacity (TAC) and risk of breast cancer. Sociodemographic data, medical history and anthropometric measurements were collected from 275 women (100 breast cancer cases & 175 controls). Participants' usual dietary intake was measured using a validated semi-quantitative food frequency questionnaire and their dietary TAC was estimated. An inverse, but non-significant, association was observed between dietary TAC and breast cancer risk. Multiple logistic regression models based on TAC of individual food groups showed that consumption of fruits and vegetables with higher TAC (μmolTE/100 g) was associated with a significantly decreased risk of breast cancer. Our study supports a protective effect of dietary antioxidants in relation to breast cancer risk. Food selection based on TAC of foods may be an effective strategy to modify the risk of cancer.

  18. Relationship between air pollution and pre-eclampsia in pregnant women: a case-control study.

    PubMed

    Nahidi, F; Gholami, R; Rashidi, Y; Majd, H Alavi

    2014-01-09

    Pre-eclampsia is the main cause of maternal and fetal death and disability worldwide. Its incidence in the Islamic Republic of Iran is 5%-12%. Air pollution has been reported to be one of the causative factors, and this case-control study determined its effect on pre-eclampsia in 195 pregnant women (65 with pre-eclampsia and 130 without) admitted to hospitals in Tehran. Women were divided into high and low exposure groups according to the mean density of exposure to pollutants during pregnancy. There was no statistically significant relationship between exposure to air pollutants including CO, particulate matter, SO2, NO2 and O3 and pre-eclampsia. The combined effect was also not significant. Air pollution is one of the problems of modern society and its avoidance is almost impossible for pregnant women. This study should reduce concern about pregnant women living in polluted cities.

  19. Blinded case-control study of the relationship between human coronavirus NL63 and Kawasaki syndrome.

    PubMed

    Dominguez, Samuel R; Anderson, Marsha S; Glodé, Mary P; Robinson, Christine C; Holmes, Kathryn V

    2006-12-15

    We conducted a blinded, case-control, retrospective study in pediatric patients hospitalized at The Children's Hospital, Denver, Colorado, to determine whether human coronavirus (HCoV)-NL63 infection is associated with Kawasaki syndrome (KS). Over the course of a 7-month period, nasopharyngeal-wash samples from 2 (7.7%) of 26 consecutive children with KS and 4 (7.7%) of 52 matched control subjects tested positive for HCoV-NL63 by reverse transcription-polymerase chain reaction. These data suggest that, although HCoV-NL63 was circulating in children in our community during the time of the study, the prevalence of infection with HCoV-NL63 was not greater in patients with KS than in control subjects.

  20. Risk factors for cellulitis in patients with lymphedema: a case-controlled study.

    PubMed

    Teerachaisakul, M; Ekataksin, W; Durongwatana, S; Taneepanichskul, S

    2013-09-01

    Risk factors for cellulitis in lymphedema (LE) have never been evaluated in controlled studies. The objective of this study was to assess the risk factors for cellulitis in patients with LE using a case-controlled study method. Medical records of patients from November 2009 to September 2011 who met the following criteria were retrieved and analyzed: (a) clinical diagnosis of LE of the limb, (b) aged 18 or above, (c) no food allergy history and (d) no medical diagnosis of cancer metastasis. Overall, there were 179 cases of LE with cellulitis. Each case was matched by age (+/- 5 years) and gender with a patient with LE and without cellulitis for controls. Logistic regression with backward selection procedure was used to identify independent risk factors. The area under the receiver operating characteristics (ROC) curve of the final model was calculated. Independent risk factors for cellulitis in patients with LE were percentage difference in circumference of the limb (adjusted odds ratio (AOR)=1.07, 95% confidence interval (CI)=1.04-1.10), primary LE diagnosis (AOR=3.36, 95% CI=1.37-8.22), food-induced complication experiences (FIE: AOR=6.82, 95% CI=2.82-16.51) and systolic blood pressure (AOR=1.02, 95% CI=1.01-1.04). The area under the curve for the model was 0.80 (95% CI=0.75-0.85, p<0.001). No association was observed with hypertension, diabetes mellitus, body mass index and the duration of LE. This first case-controlled study highlights the important roles of dietary factors, percentage difference in circumference of the limb, and systolic blood pressure for developing cellulitis. The results suggest that controlling the percentage difference in circumference of the limb and systolic blood pressure together with restriction of fatty food and meat consumption may result in a decreased incidence of cellulitis among patients with LE.

  1. Case-control association study of TGOLN2 in attempted suicide.

    PubMed

    Mahon, Pamela B; Stütz, Adrian M; Seifuddin, Fayaz; Huo, Yuqing; Goes, Fernando S; Jancic, Dubravka; Judy, Jennifer T; Depaulo, J Raymond; Gershon, Elliot S; McMahon, Francis J; Zandi, Peter P; Potash, James B; Willour, Virginia L

    2010-07-01

    Family, twin, and adoption studies provide convincing evidence for a genetic contribution to suicidal behavior. The heritability for suicidal behavior depends in part on the transmission of psychiatric disorders, such as mood disorders and substance use disorders, but is also partly independent of them. Three linkage studies using the attempted suicide phenotype in pedigrees with bipolar disorder, major depression, or alcoholism have provided consistent evidence that 2p11-12 harbors a susceptibility gene for attempted suicide. A microarray expression study using postmortem brain samples has implicated a gene from the 2p11-12 candidate region, the trans-Golgi network protein 2 (TGOLN2) gene, as being consistently up-regulated in suicide cases as compared to controls. Here, we present a TGOLN2 case-control association study using nine single nucleotide polymorphisms (SNPs). These nine SNPs, which include seven tag SNPs and two coding SNPs, have been genotyped in 517 mood disorder subjects with a history of attempted suicide and 515 normal controls. Allelic and genotypic analyses of the case-control sample did not provide evidence for association with the attempted suicide phenotype. Eight of the nine SNPs provided supportive evidence for association (P-values ranging from 0.008 to 0.03) when we compared the attempted suicide cases with a history of alcoholism to the attempted suicide cases without a history of alcoholism. However, this association finding was not replicated in an independent sample. Taken together, these analyses do not provide support for the hypothesis that common genetic variation in TGOLN2 contributes significantly to the risk for attempted suicide in subjects with major mood disorders.

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

    PubMed

    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.

  3. Sleep problems and suicide attempts among adolescents: a case-control study.

    PubMed

    Koyawala, Neel; Stevens, Jack; McBee-Strayer, Sandra M; Cannon, Elizabeth A; Bridge, Jeffrey A

    2015-01-01

    This study used a case-control design to compare sleep disturbances in 40 adolescents who attempted suicide with 40 never-suicidal adolescents. Using hierarchical logistic regression analyses, we found that self-reported nighttime awakenings were significantly associated with attempted suicide, after controlling for antidepressant use, antipsychotic use, affective problems, and being bullied. In a separate regression analysis, the parent-reported total sleep problems score also predicted suicide attempt status, controlling for key covariates. No associations were found between suicide attempts and other distinct sleep problems, including falling asleep at bedtime, sleeping a lot during the day, trouble waking up in the morning, sleep duration, and parent-reported nightmares. Clinicians should be aware of sleep problems as potential risk factors for suicide attempts for adolescents.

  4. A case-control study of Salmonella gastrointestinal infection in Italian children.

    PubMed

    Borgnolo, G; Barbone, F; Scornavacca, G; Franco, D; Vinci, A; Iuculano, F

    1996-07-01

    A case-control study of 85 cases with non-typhoid Salmonella gastroenteritis, 85 outpatient controls and 79 inpatient controls was conducted among children in Monfalcone, north-east Italy, between June 1989 and June 1994. Logistic regression was used to evaluate the effect of demographic and socio-economic characteristics, duration of breastfeeding, history of intestinal illnesses and household diarrhoea, and the recent use of antimicrobials. Breastfeeding was the single most important factor associated with a 5-fold decreased risk of Salmonella infection. In addition, children who were treated with antimicrobials before onset of gastroenteritis had a 3-fold increased risk. Low social class and history of other chronic non-infectious intestinal diseases were also directly associated with illness.

  5. Bladder cancer in Massachusetts related to chlorinated and chloraminated drinking water: a case-control study

    SciTech Connect

    Zierler, S.; Feingold, L.; Danley, R.A.; Craun, G.

    1988-03-01

    Consumers of chlorinated drinking water have a small excess of bladder cancer. Risk may have been underestimated because of confounding and misclassification of exposure status. To address these problems, we undertook a case-control study. Detailed residential histories were obtained by telephone interviews with informants of 614 individuals who died of primarily bladder cancer and 1,074 individuals who died of other causes. Their surface water has been disinfected with chlorine or a combination of chlorine and ammonia (cloramine) since 1938. The mortality ratio for bladder cancer among individuals who resided only in communities supplied with drinking water disinfected with chlorine, relative to individuals who resided only in communities supplied with drinking water disinfected with chloramine, was 1.6 (95% confidence interval = 1.2-2.1), using all controls; when the comparison group was restricted to individuals who died of lymphoma, the mortality odds ratio was 2.7 (95% confidence interval = 1.7-4.3).

  6. Bladder cancer in Massachusetts related to chlorinated and chloraminated drinking water: a case-control study.

    PubMed

    Zierler, S; Feingold, L; Danley, R A; Craun, G

    1988-01-01

    Consumers of chlorinated drinking water have a small excess of bladder cancer. Risk may have been underestimated because of confounding and misclassification of exposure status. To address these problems, we undertook a case-control study. Detailed residential histories were obtained by telephone interviews with informants of 614 individuals who died of primarily bladder cancer and 1,074 individuals who died of other causes. Their surface water has been disinfected with chlorine or a combination of chlorine and ammonia (cloramine) since 1938. The mortality ratio for bladder cancer among individuals who resided only in communities supplied with drinking water disinfected with chlorine, relative to individuals who resided only in communities supplied with drinking water disinfected with chloramine, was 1.6 (95% confidence interval = 1.2-2.1), using all controls; when the comparison group was restricted to individuals who died of lymphoma, the mortality odds ratio was 2.7 (95% confidence interval = 1.7-4.3).

  7. Incidence of basilar invagination in patients with tonsillar herniation? A case control craniometrical study.

    PubMed

    Joaquim, Andrei F; Fernandes, Yvens Barbosa; Mathias, Roger N; Batista, Ulysses C; Ghizoni, Enrico; Tedeschi, Helder; Patel, Alpesh A

    2014-09-01

    A retrospective case-control study based on craniometrical evaluation was performed to evaluate the incidence of basilar invagination (BI). Patients with symptomatic tonsillar herniation treated surgically had craniometrical parameters evaluated based on CT scan reconstructions before surgery. BI was diagnosed when the tip of the odontoid trespassed the Chamberlain's line in three different thresholds found in the literature: 2, 5 or 6.6 mm. In the surgical group (SU), the mean distance of the tip of the odontoid process above the Chamberlain's line was 12 mm versus 1.2 mm in the control (CO) group (p<0.0001). The number of patients with BI according to the threshold used (2, 5 or 6.6 mm) in the SU group was respectively 19 (95%), 16 (80%) and 15 (75%) and in the CO group it was 15 (37%), 4 (10%) and 2 (5%).

  8. Nutritional status of children with autism spectrum disorders (ASDs): a case-control study.

    PubMed

    Marí-Bauset, Salvador; Llopis-González, Agustín; Zazpe-García, Itziar; Marí-Sanchis, Amelia; Morales-Suárez-Varela, María

    2015-01-01

    Children with autism spectrum disorder (ASD) have problems of food selectivity, implying risks of nutritional deficiencies. The aim was to compare intakes of macro and micronutrients and body mass index in ASD and typically developing (TD) children. In a case-control study, 3-day food diaries and anthropometric measurements were completed for ASD (n = 40) and TD (n = 113) children (aged 6-10 years) living in the same area. Body mass indices were below the 5th percentile in 20 % of ASD versus 8.85% of TD children. We found intakes were lower for fluoride (p = 0.017) and higher for vitamin E (p = 0.001). There was limited food variety and inadequacy of some intakes suggests that routine monitoring of ASD children should include assessment of their dietary habits, as well as anthropometric measurements.

  9. Risk factors for Enterobacter septicemia in a neonatal unit: case-control study.

    PubMed

    Fok, T F; Lee, C H; Wong, E M; Lyon, D J; Wong, W; Ng, P C; Cheung, K L; Cheng, A F

    1998-11-01

    Thirty cases of Enterobacter aerogenes or Enterobacter cloacae septicemia diagnosed over a 32-month period in a tertiary care neonatal unit were enrolled in a case-control study. Each case patient was matched with two controls (patients occupying the cots nearest the case patient when the latter developed septicemia). Of the 32 perinatal characteristics evaluated, 11 were identified by univariate analysis to be significantly associated with the infection. These included parents being residents of the Vietnamese refugee camps, respiratory distress syndrome, necrotizing enterocolitis, umbilical arterial catheterization, umbilical venous catheterization, bladder catheterization, mechanical ventilation, antibiotic treatment, peripheral venous catheterization, nasogastric intubation, and parenteral nutrition. Multivariate analysis, however, showed that preceding bladder catheterization and ongoing parenteral nutrition were the only independent risk factors for enterobacter septicemia. Strict aseptic technique in the preparation of parenteral nutrition fluid and avoidance of bladder catheterization are measures that may reduce the risk of enterobacter sepsis for newborns.

  10. A case control study to improve accuracy of an electronic fall prevention toolkit.

    PubMed

    Dykes, Patricia C; I-Ching, Evita Hou; Soukup, Jane R; Chang, Frank; Lipsitz, Stuart

    2012-01-01

    Patient falls are a serious and commonly report adverse event in hospitals. In 2009, our team conducted the first randomized control trial of a health information technology-based intervention that significantly reduced falls in acute care hospitals. However, some patients on intervention units with access to the electronic toolkit fell. The purpose of this case control study was to use data mining and modeling techniques to identify the factors associated with falls in hospitalized patients when the toolkit was in place. Our ultimate aim was to apply our findings to improve the toolkit logic and to generate practice recommendations. The results of our evaluation suggest that the fall prevention toolkit logic is accurate but strategies are needed to improve adherence with the fall prevention intervention recommendations generated by the electronic toolkit.

  11. A case control study on the lung cancer risk factors in north of Iran.

    PubMed

    Karimzadeh, Laleh; Koohdani, Fariba; Siassi, Fereydoon; Mahmoudi, Mahmoud; Moslemi, Dariush; Shokrzadeh, Mohammad; Safari, Farid

    2011-01-01

    In this case control study, the risk factors of lung cancer was assessed in the north of Iran. Two groups were matched for gender and age (+/- 5 years). Data were collected from 40 cases and 40 controls attending to hospitals. A public information questionnaire was used for data collection. Incidence odds ratios (OR) and corresponding 95% confidence intervals calculated using logistic regression analyses. Results showed that in adjusted odd ratio positive family history of cancer (OR = 0/19, 95% CI: 0/04-0/8) was associated with a reduction, and consumption of baked bread in traditional oven (OR = 22/6, 95% CI: 1/9-270), was associated with increase in lung cancer risk. Based on the results, smoking was not correlated with lung cancer. In conclusion, the data offers consumption of traditional oven-baked bread may enhance the risk of lung cancer but positive family history of cancer may reduce it.

  12. Chemical exposures and Parkinson's disease: a population-based case-control study.

    PubMed

    Frigerio, Roberta; Sanft, Kevin R; Grossardt, Brandon R; Peterson, Brett J; Elbaz, Alexis; Bower, James H; Ahlskog, J Eric; de Andrade, Mariza; Maraganore, Demetrius M; Rocca, Walter A

    2006-10-01

    The putative association between pesticide exposures and Parkinson's disease (PD) remains controversial. We identified all subjects who developed PD in Olmsted County, Minnesota, from 1976 through 1995, and matched them by age (+/- 1 year) and sex to general population controls. We assessed exposures to chemical products by means of telephone interview with cases, controls, or their proxies (149 cases; 129 controls). Exposure to pesticides related or unrelated to farming was associated with PD in men (odds ratio, 2.4; 95% confidence interval, 1.1-5.4; P = 0.04). The association remained significant after adjustment for education or smoking. Analyses for the other six categories of industrial and household chemicals were all nonsignificant. This population-based study suggests a link between pesticides use and PD that is restricted to men. Pesticides may interact with other genetic or nongenetic factors that are different in men and women.

  13. Case-control study of diesel exhaust exposure and bladder cancer

    SciTech Connect

    Wynder, E.L.; Dieck, G.S.; Hall, N.E.L.; Lahti, H.

    1985-08-01

    The relationship between bladder cancer and employment in occupations involving exposure to diesel exhaust was examined using data from a hospital-based case-control study of men aged 20 to 80 years in 18 hospitals in six US cities, from January 1981 to May 1983. In this analysis, 194 cases and 582 controls were compared according to occupation, smoking history, alcohol and coffee consumption, and various demographic variables. No difference was found in the proportion of bladder cancer cases employed in occupations with exposure to diesel exhaust compared to controls. This relationship did not change after taking smoking habits into account. Bladder cancer cases were significantly more likely to be current smokers of cigarettes than were controls.

  14. [A population-based case control study of primary liver cancer in Fusui].

    PubMed

    Zhang, M D

    1993-02-01

    A population-based case control study of primary liver cancer (PLC) was undertaken in Fusui County, Guangxi Autonomous Region. Ninety-nine PLC cases and 99 age-sex-matched controls were surveyed for their general conditions, life style features, dietary habits, types of drinking water and family history. Cases and controls were well distributed in nationality, education, marital status and annual income per person. Conditional logistic regression results showed that HBV infection, drinking pond-ditch water, family history and total alcohol intake were the risk factors of PLC with the relative risks 5.330 (2.502-11.35), 3.703 (1.251-10.96), 2.881 (1.289-6.441), 1.002 (1.000-1.004), respectively. And antibody of HBV surface antigen is protective factor with the relative risk of 0.418 (0.210-0.834).

  15. Case-control study of intracranial meningiomas in women in Los Angeles County, California

    SciTech Connect

    Preston-Martin, S.; Paganini-Hill, A.; Henderson, B.E.; Pike, M.C.; Wood, C.

    1980-07-01

    A case-control study was conducted among women in Los Angeles County to investigate possible causes of intracranial meningiomas. Questionnaires sought information from patients and from a neighbor of each one on characteristics and past experiences that might be associated with the development of this disease. Information was obtained on 188 matched patient-neighbor pairs. Three primary factors appeared to be associated with meningioma occurrence: 1) a history of head trauma (odds ratio = 2.0, p = 0.01), 2) consumption of certain cured meats (odds ratio = 2.8, p = less than 0.01), and 3) exposure to medical and dental diagnostic X-rays to the head. For diagnostic X-rays, the strongest association was with early exposure (less than 20 yr old) to full-mouth dental X-ray series (odds ratio = 4.0, p less than 0.01).

  16. Postadmission sepsis as a screen for quality problems: a case-control study.

    PubMed

    Hughes, John S; Eisenhandler, Jon; Goldfield, Norbert; Weinberg, Patti G; Averill, Richard

    2014-01-01

    The present on admission (POA) indicator used with diagnosis codes listed in hospital discharge abstracts makes it possible to screen for possible in-hospital complications, which may in turn point to quality of care problems. A case-control study was performed among 382 patients from 30 New York State hospitals to see if lapses in quality were associated with the development of postadmission sepsis. Cases with hospital-acquired sepsis (labeled not POA) were compared with matched controls without sepsis. The authors found that central venous catheters and emergently inserted peripheral intravenous catheters were associated with subsequent development of sepsis. Urethral catheters were associated with sepsis for medical patients but not for surgical patients. Adherence to several process of care guidelines was incomplete but none occurred statistically significantly more frequently among sepsis cases than controls. Using discharge abstract diagnosis codes to determine the presence of postadmission complications shows promise for identifying areas for quality improvement.

  17. Case-control study of possible causative factors in mycosis fungoides

    SciTech Connect

    Tuyp, E.; Burgoyne, A.; Aitchison, T.; MacKie, R.

    1987-02-01

    A detailed case control study was carried out on 53 patients (33 males and 20 females) with histologically proven mycosis fungoides and on an age- and sex-matched control population. Possible causative factors investigated included occupation, recreation, and exposure to petrochemicals, pesticides, insecticides, and potential carcinogens. Exposure to plants of the Compositae family, tanning history, and chronic sun exposure were also investigated, as were smoking history, drug ingestion history, and other skin disease. Personal and family histories of other malignancies were also investigated. The only statistically significant difference to emerge was that the patients with mycosis fungoides had significantly more family history of atopic dermatitis. In view of the absence of any significant difference between patients and controls with regard to personal history of atopic dermatitis, this difference may be the result of multiple statistical testing rather than a phenomenon of true biological significance.

  18. A Joint Association Test for Multiple SNPs in Genetic Case-Control Studies

    PubMed Central

    Wang, Tao; Jacob, Howard; Ghosh, Soumitra; Wang, Xujing; Zeng, Zhao-Bang

    2009-01-01

    For a dense set of genetic markers such as single nucleotide polymorphisms (SNPs) on high linkage disequilibrium within a small candidate region, a haplotype-based approach for testing association between a disease phenotype and the set of markers is attractive in reducing the data complexity and increasing the statistical power. However, due to unknown status of the underlying disease variant, a comprehensive association test may require consideration of various combinations of the SNPs, which often leads to severe multiple testing problems. In this paper, we propose a latent variable approach to test for association of multiple tightly linked SNPs in case-control studies. First, we introduce a latent variable into the penetrance model to characterize a putative disease susceptible locus (DSL) that may consist of a marker allele, a haplotype from a subset of the markers, or an allele at a putative locus between the markers. Next, through using of a retrospective likelihood to adjust for the case-control sampling ascertainment and appropriately handle the Hardy-Weinberg equilibrium constraint, we develop an expectation-maximization (EM)-based algorithm to fit the penetrance model and estimate the joint haplotype frequencies of the DSL and markers simultaneously. With the latent variable to describe a flexible role of the DSL, the likelihood ratio statistic can then provide a joint association test for the set of markers without requiring an adjustment for testing of multiple haplotypes. Our simulation results also reveal that the latent variable approach may have improved power under certain scenarios comparing with classical haplotype association methods. PMID:18770519

  19. The LDLR locus in Alzheimer's disease: a family-based study and meta-analysis of case-control data.

    PubMed

    Bertram, Lars; Hsiao, Monica; McQueen, Matthew B; Parkinson, Michele; Mullin, Kristina; Blacker, Deborah; Tanzi, Rudolph E

    2007-01-01

    Genetic linkage studies suggest the presence of an Alzheimer's disease (AD) risk gene on chromosome 19, acting independently of apolipoprotein E (apoE), a known AD risk factor on 19q13. The low density lipoprotein receptor (LDLR) is an interesting candidate because it maps within the linked interval, and is intimately involved in cholesterol homeostasis and the function of apoE. We tested three previously reported single nucleotide polymorphisms (SNPs) within LDLR in a large sample of discordant sibships from multiplex AD families, and failed to find evidence for genetic association with disease risk. In addition, we performed meta-analyses for SNP rs5925 on published data from five independent case control samples, but did not detect any significant summary odds ratios. Based on our data, it seems unlikely that these genetic variants in LDLR make a significant contribution to AD risk in the general population.

  20. Usefulness of blink reflex in hypothyroid patients with or without polyneuropathy: a case control study.

    PubMed

    Pawar, Sachin; Udan, Vikas; Jain, Jyoti; Shende, Vinod; Singh, Ramji

    2014-01-01

    Central nervous system (CNS) dysfunction is an important consequence of thyroid deficiency. Cranial nerves are frequently affected in hypothyroid process. On routine nerve conduction studies, symptomatic peripheral and cranial neuropathy can be detected, however, diagnosing subclinical cranial neuropathy pose the major problem. Blink reflex (BR), has been shown to be an effective method for revealing subclinical involvement of cranial nerves in generalized neuropathies. The present study was undertaken to evaluate the efficacy of BR as a method for early diagnosis of subclinical cranial neuropathy in hypothyroid patients with or without overt peripheral polyneuropathy. A case control study was conducted on 150 subjects aged 18 years and above (100 controls, 50 cases). A routine nerve conduction study and BR evaluation was done in all the subjects. We found abnormal BR response in 50% of hypothyroid patients studied. In hypothyroid patient without polyneuropathy R1 latency was significantly prolonged (P < 0.05 Vs control). Ipsilateral and contralateral R2 latencies were significantly prolonged in hypothyroid cases with or without polyneuropathy on bilateral stimulation. Magnitude of prolongation was greater in with polyneuropathy group. In conclusion, study suggests that BR is a useful non-invasive method for the detection of clinically silent cranial nerve compromise in hypothyroid patients.

  1. Diagonal Earlobe Crease as a Significant Marker for Coronary Artery Disease: A Case-control Study

    PubMed Central

    Kamal, Rida; Kausar, Komal; Minto, Moeed H; Ilyas, Fariha; Assad, Salman; Shah, Saeed U

    2017-01-01

    Objectives: To investigate the association between diagonal earlobe crease (DELC) and coronary artery disease (CAD). Limited data exists in South Asia and no prior studies have been performed in Pakistan to assess this relationship. Methods: In this case-control study, 200 participants from December 2015 to March 2016 at Shifa International Hospital, Islamabad, Pakistan were enrolled. Consecutive non-probability sampling was used to recruit patients. Cases were enrolled from cardiac care unit (CCU) of the hospital with angiography-proven CAD. Controls were selected from surgical, medical and neurology units of the hospital if they had no previously established evidence or symptoms of CAD. Patients were evaluated in terms of age and any history of hypertension, diabetes and/or smoking. Cases and controls were examined separately by two investigators for the unilateral or bilateral presence of DELC of the lobular portion of either auricle. Patients with ear piercings were excluded from the study. The data was analyzed in statistical product and service solutions (SPSS) (IBM, Delaware, Chicago), and an online statistical software. Results: Out of the 200 patients, 126 (63%) were males and 74 (37%) were females. In the 100 cases, 76 had DELC and 24 had no crease whereas, among the 100 controls, 36 had DELC and 64 had no DELC (p <0.001, OR = 5.63, CI = 2.91-10.93). The prevalence of diseases such as hypertension, diabetes, smoking among the cases and controls were 66%, 53%, 27% and 27%, 18%, 25% respectively. The effect of hypertension and diabetes on the presence of DELC was statistically significant (p <0.05) but the impact of smoking on DELC presence was insignificant (p >0.05). Conclusion: There is a significant association between DELC and CAD. This is the first case-control study from South Asia disclosing this important correlation. Our study also reports a high frequency of DELC in patients suffering from hypertension and diabetes mellitus. No association

  2. Lung cancer among glass fibre production workers: a case-control study.

    PubMed Central

    Gardner, M J; Magnani, C; Pannett, B; Fletcher, A C; Winter, P D

    1988-01-01

    A cohort study among 4734 employees at an English glass fibre plant previously reported no excess of lung cancer mortality either overall or when examined in broad occupational groups. To investigate occupation in more detail, and to test the hypothesis that processes producing or using finer (respirable) fibres may be related to a higher risk of lung cancer, a nested case-control study has now been carried out. Included are 73 cases of lung cancer and 506 matched controls, for whom jobs held and processes worked on have been blindly recorded in more detail than for the cohort study. Workers known to have been employed on processes containing respirable fibres had a relative risk of lung cancer of 1.2 (95% confidence interval 0.7-2.0) compared with other workers. There was no evidence of a relationship of lung cancer to fibre diameter, duration of exposure, or time since first exposure. The results by broad occupational group were similar to those of the cohort study, and although some of the many detailed occupational categories examined had significantly raised relative risks, these did not appear to be related to exposure to respirable glass fibre. Although the study has not indicated a differential risk of lung cancer among workers exposed to finer diameter glass fibres, the exposure levels were low and the number of cases small. PMID:3179236

  3. Depressive Symptoms and Resilience among Pregnant Adolescents: A Case-Control Study

    PubMed Central

    Salazar-Pousada, Danny; Arroyo, Dalton; Hidalgo, Luis; Pérez-López, Faustino R.; Chedraui, Peter

    2010-01-01

    Background. Data regarding depression and resilience among adolescents is still lacking. Objective. To assess depressive symptoms and resilience among pregnant adolescents. Method. Depressive symptoms and resilience were assessed using two validated inventories, the 10-item Center for Epidemiologic Studies Short Depression Scale (CESD-10) and the 14-item Wagnild and Young Resilience Scale (RS), respectively. A case-control approach was used to compare differences between adolescents and adults. Results. A total of 302 pregnant women were enrolled in the study, 151 assigned to each group. Overall, 56.6% of gravids presented total CESD-10 scores 10 or more indicating depressed mood. Despite this, total CESD-10 scores and depressed mood rate did not differ among studied groups. Adolescents did however display lower resilience reflected by lower total RS scores and a higher rate of scores below the calculated median (P < .05). Logistic regression analysis could not establish any risk factor for depressed mood among studied subjects; however, having an adolescent partner (OR, 2.0 CI 95% 1.06–4.0, P = .03) and a preterm delivery (OR, 3.0 CI 95% 1.43–6.55, P = .004) related to a higher risk for lower resilience. Conclusion. In light of the findings of the present study, programs oriented at giving adolescents support before, during, and after pregnancy should be encouraged. PMID:21461335

  4. Lung Cancer Risk Among Hairdressers: A Pooled Analysis of Case-Control Studies Conducted Between 1985 and 2010

    PubMed Central

    Olsson, Ann C.; Xu, Yiwen; Schüz, Joachim; Vlaanderen, Jelle; Kromhout, Hans; Vermeulen, Roel; Peters, Susan; Stücker, Isabelle; Guida, Florence; Brüske, Irene; Wichmann, Heinz-Erich; Consonni, Dario; Landi, Maria Teresa; Caporaso, Neil; Tse, Lap Ah; Yu, Ignatius Tak-sun; Siemiatycki, Jack; Richardson, Lesley; Mirabelli, Dario; Richiardi, Lorenzo; Simonato, Lorenzo; Gustavsson, Per; Plato, Nils; Jöckel, Karl-Heinz; Ahrens, Wolfgang; Pohlabeln, Hermann; Tardón, Adonina; Zaridze, David; Marcus, Michael W.; ‘t Mannetje, Andrea; Pearce, Neil; McLaughlin, John; Demers, Paul; Szeszenia-Dabrowska, Neonila; Lissowska, Jolanta; Rudnai, Peter; Fabianova, Eleonora; Dumitru, Rodica Stanescu; Bencko, Vladimir; Foretova, Lenka; Janout, Vladimir; Boffetta, Paolo; Fortes, Cristina; Bueno-de-Mesquita, Bas; Kendzia, Benjamin; Behrens, Thomas; Pesch, Beate; Brüning, Thomas; Straif, Kurt

    2013-01-01

    Increased lung cancer risks among hairdressers were observed in large registry-based cohort studies from Scandinavia, but these studies could not adjust for smoking. Our objective was to evaluate the lung cancer risk among hairdressers while adjusting for smoking and other confounders in a pooled database of 16 case-control studies conducted in Europe, Canada, China, and New Zealand between 1985 and 2010 (the Pooled Analysis of Case-Control Studies on the Joint Effects of Occupational Carcinogens in the Development of Lung Cancer). Lifetime occupational and smoking information was collected through interviews with 19,369 cases of lung cancer and 23,674 matched population or hospital controls. Overall, 170 cases and 167 controls had ever worked as hairdresser or barber. The odds ratios for lung cancer in women were 1.65 (95% confidence interval (CI): 1.16, 2.35) without adjustment for smoking and 1.12 (95% CI: 0.75, 1.68) with adjustment for smoking; however, women employed before 1954 also experienced an increased lung cancer risk after adjustment for smoking (odds ratio = 2.66, 95% CI: 1.09, 6.47). The odds ratios in male hairdressers/barbers were generally not elevated, except for an increased odds ratio for adenocarcinoma in long-term barbers (odds ratio = 2.20, 95% CI: 1.02, 4.77). Our results suggest that the increased lung cancer risks among hairdressers are due to their smoking behavior; single elevated risk estimates should be interpreted with caution and need replication in other studies. PMID:24068200

  5. Lung cancer risk among hairdressers: a pooled analysis of case-control studies conducted between 1985 and 2010.

    PubMed

    Olsson, Ann C; Xu, Yiwen; Schüz, Joachim; Vlaanderen, Jelle; Kromhout, Hans; Vermeulen, Roel; Peters, Susan; Stücker, Isabelle; Guida, Florence; Brüske, Irene; Wichmann, Heinz-Erich; Consonni, Dario; Landi, Maria Teresa; Caporaso, Neil; Tse, Lap Ah; Yu, Ignatius Tak-sun; Siemiatycki, Jack; Richardson, Lesley; Mirabelli, Dario; Richiardi, Lorenzo; Simonato, Lorenzo; Gustavsson, Per; Plato, Nils; Jöckel, Karl-Heinz; Ahrens, Wolfgang; Pohlabeln, Hermann; Tardón, Adonina; Zaridze, David; Marcus, Michael W; 't Mannetje, Andrea; Pearce, Neil; McLaughlin, John; Demers, Paul; Szeszenia-Dabrowska, Neonila; Lissowska, Jolanta; Rudnai, Peter; Fabianova, Eleonora; Dumitru, Rodica Stanescu; Bencko, Vladimir; Foretova, Lenka; Janout, Vladimir; Boffetta, Paolo; Fortes, Cristina; Bueno-de-Mesquita, Bas; Kendzia, Benjamin; Behrens, Thomas; Pesch, Beate; Brüning, Thomas; Straif, Kurt

    2013-11-01

    Increased lung cancer risks among hairdressers were observed in large registry-based cohort studies from Scandinavia, but these studies could not adjust for smoking. Our objective was to evaluate the lung cancer risk among hairdressers while adjusting for smoking and other confounders in a pooled database of 16 case-control studies conducted in Europe, Canada, China, and New Zealand between 1985 and 2010 (the Pooled Analysis of Case-Control Studies on the Joint Effects of Occupational Carcinogens in the Development of Lung Cancer). Lifetime occupational and smoking information was collected through interviews with 19,369 cases of lung cancer and 23,674 matched population or hospital controls. Overall, 170 cases and 167 controls had ever worked as hairdresser or barber. The odds ratios for lung cancer in women were 1.65 (95% confidence interval (CI): 1.16, 2.35) without adjustment for smoking and 1.12 (95% CI: 0.75, 1.68) with adjustment for smoking; however, women employed before 1954 also experienced an increased lung cancer risk after adjustment for smoking (odds ratio = 2.66, 95% CI: 1.09, 6.47). The odds ratios in male hairdressers/barbers were generally not elevated, except for an increased odds ratio for adenocarcinoma in long-term barbers (odds ratio = 2.20, 95% CI: 1.02, 4.77). Our results suggest that the increased lung cancer risks among hairdressers are due to their smoking behavior; single elevated risk estimates should be interpreted with caution and need replication in other studies.

  6. Tumor-based case-control studies of infection and cancer: muddling the when and where of molecular epidemiology.

    PubMed

    Engels, Eric A; Wacholder, Sholom; Katki, Hormuzd A; Chaturvedi, Anil K

    2014-10-01

    We describe the "tumor-based case-control" study as a type of epidemiologic study used to evaluate associations between infectious agents and cancer. These studies assess exposure using diseased tissues from affected individuals (i.e., evaluating tumor tissue for cancer cases), but they must utilize nondiseased tissues to assess control subjects, who do not have the disease of interest. This approach can lead to exposure misclassification in two ways. First, concerning the "when" of exposure assessment, retrospective assessment of tissues may not accurately measure exposure at the key earlier time point (i.e., during the etiologic window). Second, concerning the "where" of exposure assessment, use of different tissues in cases and controls can have different accuracy for detecting the exposure (i.e., differential exposure misclassification). We present an example concerning the association of human papillomavirus with various cancers, where tumor-based case-control studies likely overestimate risk associated with infection. In another example, we illustrate how tumor-based case-control studies of Helicobacter pylori and gastric cancer underestimate risk. Tumor-based case-control studies can demonstrate infection within tumor cells, providing qualitative information about disease etiology. However, measures of association calculated in tumor-based case-control studies are prone to over- or underestimating the relationship between infections and subsequent cancer risk.

  7. Housing and tuberculosis in an Inuit village in northern Quebec: a case-control study

    PubMed Central

    Khan, Faiz Ahmad; Fox, Greg J.; Lee, Robyn S.; Riva, Mylene; Benedetti, Andrea; Proulx, Jean-François; Jung, Shelley; Hornby, Karen; Behr, Marcel A.; Menzies, Dick

    2016-01-01

    Background: Between November 2011 and November 2012, an Inuit village in Nunavik, Quebec experienced a surge in the occurrence of active TB; contact investigations showed that TB infection was highly prevalent (62.6%), particularly among those over age 14 years (78.8%). A nested case-control study showed that nutritional inadequacy was associated with acquisition of infection but not progression to disease. We performed a study to determine whether characteristics of one's dwelling were associated with 1) acquisition of newly diagnosed TB infection and 2) progression to confirmed or probable disease among those with TB infection. Methods: In this nested case-control study, we enrolled 200 people who were household or social contacts of at least 1 person with active TB or had received a diagnosis of active TB and assessed whether characteristics of their dwellings were associated with their odds of having newly diagnosed TB infection and/or odds of progression to disease between November 2011 and November 2012. For our first objective, we compared participants with newly diagnosed TB infection (regardless of their disease status) to a control group of contacts who were uninfected. For the second objective, we compared participants with confirmed or probable disease to a control group consisting of those with infection but no disease. We used information collected during investigation of the contacts and from study questionnaires to determine whether participants may have been exposed to TB in their own home (if they had shared a dwelling with someone who had smear-positive TB during the outbreak) or in other dwellings that they visited at least weekly. Results: The participants lived in 79 dwellings. The mean number of people per room was 1.1 (standard deviation [SD] 0.5). The mean room size and ventilation level of the common living space (kitchen and living/dining rooms) were 67.9 (SD 9.4) m3 and 1.69 (SD 0.26) air changes per hour, respectively. After adjustment

  8. Dairy products, calcium intake, and breast cancer risk: a case-control study in China.

    PubMed

    Zhang, Cai-Xia; Ho, Suzanne C; Fu, Jian-Hua; Cheng, Shou-Zhen; Chen, Yu-Ming; Lin, Fang-Yu

    2011-01-01

    The results of dairy food consumption and breast cancer risk are conflicting, and their relationship has not previously been studied in China. The objective of this study is to examine the association between dairy products, calcium intake, and breast cancer risk among Chinese women. A hospital-based case-control study was conducted among Chinese women in the Guangdong province from June 2007 to August 2008. Four hundred and thirty-eight consecutively recruited cases with primary breast cancer were frequency-matched to 438 controls on age and residence. Dietary intake information was collected by interviewers using a validated food frequency questionnaire. Odds ratios (ORs) and 95% confidence interval (CI) were estimated using unconditional multiple logistic regression adjusted for various potential confounders. We observed a statistically significant inverse association of dietary calcium intake with breast cancer risk, with the adjusted OR (95% CI) of 0.35 (0.22-0.56) comparing the highest with the lowest quartile. No significant association was found between dairy products measured either by dry weight of dairy product or dairy product protein intake and breast cancer risk. Our study supports a protective effect of high intake of dietary calcium on breast cancer risk, and no association with dairy product intake.

  9. XPG Gene Polymorphisms Contribute to Colorectal Cancer Susceptibility: A Two-Stage Case-Control Study

    PubMed Central

    Hua, Rui-Xi; Zhuo, Zhen-Jian; Zhu, Jinhong; Zhang, Shao-Dan; Xue, Wen-Qiong; Zhang, Jiang-Bo; Xu, Hong-Mei; Li, Xi-Zhao; Zhang, Pei-Fen; He, Jing; Jia, Wei-Hua

    2016-01-01

    Previous studies have reported that xeroderma pigmentosum group G (XPG) gene polymorphisms may modulate colorectal cancer (CRC) susceptibility. In this study, we performed a two-stage case-control study to comprehensively investigate the associations of five polymorphisms in the XPG gene with CRC risk in 1,901 cases and 1,976 controls from Southern China, including rs2094258 C>T, rs751402 C>T, rs2296147 T>C, rs1047768 T>C and rs873601 G>A. After combining data from two stages, we found that three of the studied polymorphisms (rs2094258 C>T, rs751402 C>T, and rs873601 G>A) were significantly associated with CRC susceptibility. After adjustment for age and gender, multivariate logistic regression analysis indicated that carriers of the rs2094258 T alleles had an increased CRC risk [CT vs. CC: adjusted odds ratio (OR)=1.17, 95% confidence interval (CI)=1.01-1.36; TT vs. CC: adjusted OR=1.49, 95% CI=1.18-1.89; TT vs. CT/CC: adjusted OR=1.38, 95% CI=1.10-1.72]. Likely, rs873601 A allele also conferred increased CRC susceptibility. In contrast, a protective association was identified between rs751402 C>T polymorphism and the risk of CRC. In summary, our results indicated that these three polymorphisms were found to associate with CRC susceptibility in a Southern Chinese population. PMID:27698911

  10. Simple F Test Reveals Gene-Gene Interactions in Case-Control Studies

    PubMed Central

    Chen, Guanjie; Yuan, Ao; Zhou, Jie; Bentley, Amy R.; Adeyemo, Adebowale; Rotimi, Charles N.

    2012-01-01

    Missing heritability is still a challenge for Genome Wide Association Studies (GWAS). Gene-gene interactions may partially explain this residual genetic influence and contribute broadly to complex disease. To analyze the gene-gene interactions in case-control studies of complex disease, we propose a simple, non-parametric method that utilizes the F-statistic. This approach consists of three steps. First, we examine the joint distribution of a pair of SNPs in cases and controls separately. Second, an F-test is used to evaluate the ratio of dependence in cases to that of controls. Finally, results are adjusted for multiple tests. This method was used to evaluate gene-gene interactions that are associated with risk of Type 2 Diabetes among African Americans in the Howard University Family Study. We identified 18 gene-gene interactions (P < 0.0001). Compared with the commonly-used logistical regression method, we demonstrate that the F-ratio test is an efficient approach to measuring gene-gene interactions, especially for studies with limited sample size. PMID:22837643

  11. Reptiles, amphibians, and human Salmonella infection: a population-based, case-control study.

    PubMed

    Mermin, Jonathan; Hutwagner, Lori; Vugia, Duc; Shallow, Sue; Daily, Pamela; Bender, Jeffrey; Koehler, Jane; Marcus, Ruthanne; Angulo, Frederick J

    2004-04-15

    To estimate the burden of reptile- and amphibian-associated Salmonella infections, we conducted 2 case-control studies of human salmonellosis occurring during 1996-1997. The studies took place at 5 Foodborne Diseases Active Surveillance Network (FoodNet) surveillance areas: all of Minnesota and Oregon and selected counties in California, Connecticut, and Georgia. The first study included 463 patients with serogroup B or D Salmonella infection and 7618 population-based controls. The second study involved 38 patients with non-serogroup B or D Salmonella infection and 1429 controls from California only. Patients and controls were interviewed about contact with reptiles and amphibians. Reptile and amphibian contact was associated both with infection with serogroup B or D Salmonella (multivariable odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1-2.2; P<.009) and with infection with non-serogroup B or D Salmonella (OR, 4.2; CI, 1.8-9.7; P<.001). The population attributable fraction for reptile or amphibian contact was 6% for all sporadic Salmonella infections and 11% among persons <21 years old. These data suggest that reptile and amphibian exposure is associated with approximately 74,000 Salmonella infections annually in the United States.

  12. Herb-Induced Liver Injury in the Berlin Case-Control Surveillance Study

    PubMed Central

    Douros, Antonios; Bronder, Elisabeth; Andersohn, Frank; Klimpel, Andreas; Kreutz, Reinhold; Garbe, Edeltraut; Bolbrinker, Juliane

    2016-01-01

    Herb-induced liver injury (HILI) has recently attracted attention due to increasing reports of hepatotoxicity associated with use of phytotherapeutics. Here, we present data on HILI from the Berlin Case-Control Surveillance Study. The study was initiated in 2000 to investigate the serious toxicity of drugs including herbal medicines. Potential cases of liver injury were ascertained in more than 180 Departments of all 51 Berlin hospitals from October 2002 to December 2011. Drug or herb intake was assessed through a standardized face-to-face interview. Drug or herbal aetiology was assessed based on the updated Council for International Organizations of Medical Sciences scale. In ten of all 198 cases of hepatotoxicity included in the study, herbal aetiology was assessed as probable (once ayurvedic herb) or possible (Valeriana five times, Mentha piperita once, Pelargonium sidoides once, Hypericum perforatum once, Eucalyptus globulus once). Mean age was 56.4 ± 9.7 years, and the predominant pattern of liver injury was hepatocellular. No cases of acute liver failure or death were observed. This case series corroborates known risks for ayurvedic herbs, supports the suspected association between Valeriana use and liver injury, and indicates a hepatotoxic potential for herbs such as Pelargonium sidoides, Hypericum perforatum or Mentha piperita that were rarely associated with liver injury before. However, given that possible causality does not prove clinical significance, further studies in this field are needed. PMID:26784183

  13. The association between gall bladder mucoceles and hyperlipidaemia in dogs: a retrospective case control study.

    PubMed

    Kutsunai, M; Kanemoto, H; Fukushima, K; Fujino, Y; Ohno, K; Tsujimoto, H

    2014-01-01

    The diagnosis of gall bladder mucoceles (GM) in dogs has become increasingly frequent in veterinary medicine. Primary breed-specific hyperlipidaemia is reported in Shetland Sheepdogs and Miniature Schnauzers, breeds in which GM are known to occur more frequently than in other breeds. The objective of this study was to evaluate the association between GM and hyperlipidaemia in dogs. The study design was a retrospective case control study. Medical records of dogs diagnosed with GM at the Veterinary Medical Centre of The University of Tokyo between 1 April 2007 and 31 March 2012, were reviewed. Fifty-eight dogs with GM and a record of either serum cholesterol, triglyceride, or glucose concentrations were included in the study. Hypercholesterolaemia (15/37 cases; odds ratio [OR]: 2.92; 95% confidence interval [CI]: 1.02-8.36) and hypertriglyceridaemia (13/24 cases; OR: 3.55; 95% CI:1.12-15.91) showed significant association with GM. Pomeranians (OR: 10.69), American Cocker Spaniels (OR: 8.94), Shetland Sheepdogs (OR: 6.21), Miniature Schnauzers (OR: 5.23), and Chihuahuas (OR: 3.06) were significantly predisposed to GM. Thirty-nine out of 58 cases had at least one concurrent disease, including pancreatitis (five cases), hyperadrenocorticism (two cases), and hypothyroidism (two cases). A significant association between GM and hyperlipidaemia was confirmed, suggesting that hyperlipidaemia may play a role in the pathogenesis of GM.

  14. Chili pepper consumption and gastric cancer in Mexico: a case-control study.

    PubMed

    López-Carrillo, L; Hernández Avila, M; Dubrow, R

    1994-02-01

    Laboratory studies indicate that capsaicin, the hot-tasting component of chili peppers, may be carcinogenic. A population-based case-control study was conducted in Mexico City during 1989-1990 to evaluate the relation between chili pepper consumption and gastric cancer risk. The study included 220 incident cases and 752 controls randomly selected from the general population. Information was collected by interview. Chili pepper consumers were at high risk for gastric cancer compared with nonconsumers (age- and sex-adjusted odds ratio = 5.49, 95% confidence interval (CI) 2.72-11.06). Among consumers, there was a highly significant trend of increasing risk with increasing self-rated level of consumption (low, medium, and high) (p = 2 x 10(-7). The odds ratio for high-level consumers compared with nonconsumers was 17.11 (95% CI 7.78-37.59). However, when consumption was measured as frequency per day, a significant trend among consumers was not observed. Multivariable adjustment increased the magnitude of the chili pepper-gastric cancer association, but a significant trend among consumers (measured as frequency per day) was still not observed. Chili pepper consumption may be a strong risk factor for gastric cancer, but further studies are needed to test this hypothesis.

  15. A case-control study of toenail selenium and cancer of the breast, colon, and prostate.

    PubMed

    Ghadirian, P; Maisonneuve, P; Perret, C; Kennedy, G; Boyle, P; Krewski, D; Lacroix, A

    2000-01-01

    To study the possible role of dietary and supplementary selenium intake in the etiology of cancer, we carried out a case-control study of breast, colon, and prostate cancer in Montreal between 1989 and 1993. In this study, we were able to interview a total of 1,048 incidence cases of colon (402), breast (414) and prostate (232) cancer subjects and 688 population-based controls matched for age and gender. Of these, a total of 501 cancer cases and 202 controls produced toenail samples for their selenium concentrations, which were determined by neutron activation analysis. We found no association between toenail selenium and breast cancer (odds ratio [OR], 0.72; 95% confidence interval [CI], 0.4-1.31) or prostate cancer (OR, 1.14; 95% CI, 0.46-2.83), though we did observe a statistically significant inverse association between toenail selenium level and the risk of colon cancer for both genders combined (OR, 0.42; 95% CI, 0.19-0.93; P = .009) and for female subjects (P = .050). We also found that nonsmoker case and control subjects had higher selenium in their toenail samples. This could be due either to the nature of tobacco, which reduces selenium absorption, or to smokers' consumption of certain foods containing less selenium. Further epidemiologic studies are required to clarify the role of selenium in the etiology of certain cancers.

  16. A case-control study of postoperative pulmonary complications after laparoscopic and open cholecystectomy.

    PubMed

    Hall, J C; Tarala, R A; Hall, J L

    1996-04-01

    Postoperative pulmonary complications (PPC) are common after upper abdominal surgery. The objective of this case-control study was to compare the incidence of PPC after laparoscopic cholecystectomy (LC) and open cholecystectomy (OC) within a tertiary care center. Patients were accrued from two sequential clinical trials that evaluated the role of incentive spirometry in the prevention of PPC after abdominal surgery. Included for study were patients with gallstones undergoing elective surgery who had an American Society of Anesthesiologists (ASA) classification < 3. All patients included in the study were encouraged to use an incentive spirometer at least 10 times each hour while awake. Patients with chronic bronchitis were excluded from study, as were patients who received other forms of physical therapy. OC was performed through either a transverse or an oblique incision. There was an equitable dispersion of putative risk factors for PPC between the groups at baseline. PPC were defined as clinical features consistent with collapse/consolidation, an otherwise unexplained temperature above 38 degrees C, plus either confirmatory chest radiology or positive sputum microbiology. The incidence of PPC was 2.7% (1/37) after LC and 17.2% (10/58) after OC (p < 0.05). It is concluded that PPC are less common after laparoscopic cholecystectomy than after open cholecystectomy.

  17. Factors associated with postmenopausal osteoporosis: a case-control study of Belgrade women.

    PubMed

    Grgurevic, Anita; Gledovic, Zorana; Vujasinovic-Stupar, Nada

    2010-07-01

    The aim of this study was to investigate factors related to osteoporosis in postmenopausal women in Belgrade. A case-control study was conducted during 2006-2007. The study group consisted of 100 newly diagnosed osteoporosis patients and 100 age-matched controls (± 2 years). The inclusion criteria for the case group were newly diagnosed osteoporosis confirmed by dual-energy X-ray absorptiometry of the lumbar spine and being menopausal (at least 2 years of amenorrhea). The inclusion criteria for the control group were postmenopausal women with confirmed normal bone mineral density of the lumbar spine by dual-energy X-ray absorptiometry. All study participants were interviewed using a structured questionnaire. Univariate and multivariate logistic regression analyses were used. The following factors were significantly independently related to osteoporosis: low body weight (P < 0.001), thin constitution in childhood (P = 0.002), history of previous fracture (P = 0.033), menopause at age <47 years (P < 0.001), family history of fracture (P = 0.005), and less frequent consumption of cheese (P = 0.027) and fish (P = 0.020). The majority of factors identified may be modifiable and could be influenced to prevent postmenopausal osteoporosis.

  18. Neurotrophin Genes and Antidepressant-Worsening Suicidal Ideation: A Prospective Case-Control Study

    PubMed Central

    Ramoz, Nicolas; Shekhtman, Tatyana; Courtet, Philippe; Gorwood, Philip; Kelsoe, John R.

    2016-01-01

    Background: Antidepressant-worsening suicidal ideation is a rare but serious phenomenon. This study aimed to test for association between antidepressant-worsening suicidal ideation and polymorphisms of BDNF/NTRK2 neurotrophin pathway genes, known to be involved in depression and suicide. Methods: This was a case-control study comparing patients with antidepressant-worsening suicidal ideation to patients without. Patients were collected from the GENESE cohort (3771 depressed tianeptine-treated outpatients). Antidepressant-worsening suicidal ideation was defined by an increase of at least 2 points on the Montgomery-Åsberg Depression Rating Scale-item10 during treatment. Controls were matched for age, sex, and baseline Montgomery-Åsberg Depression Rating Scale-item10 score. Thirteen single nucleotide polymorphisms covering 5 BDNF/NTRK2 pathway genes were genotyped. Results: A total 78 cases and 312 controls were included. Two NTRK2 single nucleotide polymorphisms were associated to antidepressant-worsening suicidal ideation: rs1439050 (P=.01) and rs1867283 (P=.04). Association with rs1439050 remained significant after adjustment for potentially confounding factors, including previous suicide attempts (P<.01). Conclusions: This naturalistic prospective study is consistent with previous studies on highlighting the potential role of the neurotrophin pathway, and especially of NTRK2, in antidepressant-worsening suicidal ideation. PMID:27378793

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

    PubMed Central

    Pala, Laura; Monami, Matteo; Ciani, Silvia; Dicembrini, Ilaria; Pasqua, Alessandro; Pezzatini, Anna; Francesconi, Paolo; Cresci, Barbara; Mannucci, Edoardo; Rotella, Carlo Maria

    2012-01-01

    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. PMID:21869928

  20. Regulatory Cytokine Expression and Preterm Birth: Case-Control Study Nested in a Cohort

    PubMed Central

    Pereira, Thaís Basso de Brito; Thomaz, Erika Barbara Abreu Fonseca; do Nascimento, Flávia Raquel Fernandes; dos Santos, Ana Paula Silva de Azevedo; Batista, Rosângela Lucena Fernandes; Bettiol, Heloisa; Cavalli, Ricardo de Carvalho; Barbieri, Marco Antônio; da Silva, Antônio Augusto Moura

    2016-01-01

    Background Currently known risk factors explain only a small fraction of preterm birth (PTB). Previous PTB is one of the most important predictors. However, this information is not available in primiparous women. Few studies have looked at associations between regulatory cytokine expression (RCE) and PTB and the results are conflicting. Objective To investigate the association of RCE–Interleukin 10 (IL-10) and Transforming Growth Factor β (TGF-β)–with PTB, and to assess whether bacterial vaginosis (BV) is involved in this relationship. Methods This was a case-control study nested in a prospective cohort–called BRISA. Women with singleton pregnancies were interviewed from 22 to 25 weeks of gestational age (GA). Women were recruited from health services in São Luís, Brazil. A blood sample was collected and gynecological examination was performed. Serum IL-10 and TGF-β were determined using cytometric bead array. Nugent score >7 and/or the presence of clue cells were used for BV diagnosis. All PTB estimated by ultrasound dating performed before 20 weeks of gestational age were considered cases. Controls were selected by simple random sampling from the rest of the cohort, at a 2:1 ratio. Different models were tested, according to the main independent variable. Odds ratios (OR) and 95% confidence intervals (95%CI) were estimated by regression analyses. Results The study included 327 pregnant women, 109 cases and 218 controls. No associations were found between BV and PTB (P = 1.44; 95%CI: 0.51–3.77). Low levels of IL-10 (OR = 2.92 95%CI: 1.38–6.16) or TGF-β (OR = 16.90 95%CI: 6.42–44.51) or both simultaneously (OR = 77.16 95%CI: 7.99–744.88) were associated with increasing odds of PTB, even after adjustment for confounding. Conclusion Decreased RCE is a risk factor for PTB. This relationship, however, is not triggered by the presence of BV. Low IL-10/TGF-β levels from 22 to 25 weeks of GA could be used as early predictors of PTB. We suggest

  1. Bladder cancer and occupation: a case-control study in northern Italy.

    PubMed Central

    Porru, S; Aulenti, V; Donato, F; Boffetta, P; Fazioli, R; Cosciani Cunico, S; Alessio, L

    1996-01-01

    OBJECTIVES--A hospital based case-control study was conducted between 1992 and 1993 in the province of Brescia, a highly industrialised area in northern Italy, to evaluate occupational risk factors of bladder cancer. METHODS--The study evaluated 355 histologically confirmed cases of bladder cancer (275 men, 80 women) and 579 controls affected by urological non-neoplastic diseases (397 men, 182 women). Lifetime occupational history, smoking and drinking habits, and sociodemographic characteristics were recorded by means of a structured questionnaire. Odds ratios (ORs) were computed with adjustment for age, smoking, alcohol and coffee consumption, education, and place of residence. RESULTS--A significant (P < 0.05) increase of risk of bladder cancer were found in men for labourers in the construction industry (OR 2.1, 95% confidence interval (95% CI) 1.1-3.9) and for recreational and cultural services (OR 5.0, 95% CI 1.3-18.9). Increased risks, although not significant, were found for various other occupations and industries such as machinery mechanics, metal processers and polishers, blacksmiths, gunsmiths, painters; for transport workers, an increased risk with increasing duration of employment was found. CONCLUSIONS--Occupational exposures seem to contribute to bladder cancer risk in the area under study. PMID:8563860

  2. Risk factors for Fasciola hepatica infection in children: a case-control study.

    PubMed

    Marcos, Luis; Maco, Vicente; Samalvides, Frine; Terashima, Angélica; Espinoza, José R; Gotuzzo, Eduardo

    2006-02-01

    We conducted a case-control study to clarify the risk factors for human fascioliasis in the Northern Peruvian Altiplano. Cases (n=61) were individuals who were diagnosed as having chronic fascioliasis by faecal and/or serologic (Fas2-ELISA) studies. Controls (n=61) had negative serologic and coprological results for Fasciola hepatica. We identified an association between fascioliasis and four variables (40 analysed): the habit of drinking alfalfa juice (OR=4.5; 95% CI 1.8-11.1; P<0.001); familiarity with aquatic plants (OR=4.3; 95% CI 1.8-10.6; P<0.001); dog ownership (OR=5; 95% CI 1.7-15.1; P=0.002); and raising more than five sheep (OR=0.3; 95% CI 0.1-0.8; P=0.01). According to clinical presentation and laboratory studies, dizzy spells (P=0.01), history of jaundice (P=0.01), peripheral eosinophilia (P=0.005) and Ascaris lumbricoides in stools (P=0.001) were associated with fascioliasis. The principal exposure factor for F. hepatica infection was drinking alfalfa juice. In conclusion, we suggest that human fascioliasis in Peru should be suspected in patients from livestock-rearing areas, who present with recurrent episodes of jaundice and who have a history of consumption of alfalfa juice or aquatic plants, or who have eosinophilia.

  3. Prevalence of Intestinal Protozoa among Saudi Patients with Chronic Renal Failure: A Case-Control Study

    PubMed Central

    Hawash, Yousry A.; Dorgham, Laila Sh.; Amir, El-Amir M.; Sharaf, Osama F.

    2015-01-01

    It has been hypothesized that chronic renal failure (CRF) predisposes patients to infection with intestinal protozoa. We tested this hypothesis with a matched case-control study to determine the prevalence of these protozoa and their diarrhea associated symptoms among 50 patients with CRF (cases) from Taif, western Saudi Arabia. Fifty diarrheal patients without CRF were recruited in the study as controls. Participants were interviewed by a structured questionnaire and stool samples were collected. Samples were thoroughly examined with microscopy and three coproantigens detection kits. Enteric protozoa were detected in 21 cases and 14 controls. Blastocystis spp. were the most predominant parasite (16% in cases versus 8% in controls), followed by Giardia duodenalis (10% in cases versus 12% in controls) and Cryptosporidium spp. (10% in cases versus 6% in controls). Cyclospora cayetanensis was identified in two cases, while Entamoeba histolytica was described in one case and one control. Intestinal parasitism was positively associated with the male gender, urban residence, and travel history. Clinical symptoms of nausea/vomiting and abdominal pain were significantly varied between the parasitized cases and controls (P value ≤ 0.05). Given the results, we recommend screening all diarrheal feces for intestinal protozoa in the study's population, particularly those with CRF. PMID:26491455

  4. Determinants of Internet addiction among adolescents: a case-control study.

    PubMed

    Tsitsika, Artemis; Critselis, Elena; Louizou, Amalia; Janikian, Mari; Freskou, Aliki; Marangou, Evgenia; Kormas, Georgios; Kafetzis, Dimitrios

    2011-04-19

    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.

  5. Outdoor air pollution and cardiovascular diseases in Lebanon: a case-control study.

    PubMed

    Nasser, Zeina; Salameh, Pascale; Dakik, Habib; Elias, Elias; Abou Abbas, Linda; Levêque, Alain

    2015-01-01

    Outdoor air pollution is increasingly considered as a serious threat for cardiovascular diseases (CVD). The aim of this study is to investigate the association between outdoor pollutants and cardiovascular diseases among adults in Lebanon and to examine the possible moderator effect of cigarette smoking status on this association. A multicenter case-control study was conducted between October 2011 and October 2012. Cases were hospitalized patients diagnosed with CVD by a cardiologist while the control group subjects were free of any cardiac diseases. Information on sociodemographic characteristics, tobacco consumption, self-rated global health, pollution exposure, and other risk factors was collected using a questionnaire. The results of the logistic regression revealed that living near busy highway (OR 5.04, 95% CI (4.44-12.85), P < 0.001) and close to local diesel generator (OR 4.76, 95% CI (2.07-10.91), P < 0.001) was significantly associated with CVD. The association between the CVD and exposure to outside pollutants differed by cigarette smoking status. A clear difference was noted between nonsmokers and current smokers OR 4.6, 95% CI (1.10-19.25) and OR 10.11, 95% CI (7.33-20.23), respectively. Forthcoming studies are needed to clarify the potential link between outdoor air pollution and cardiovascular diseases in Lebanon. Public health interventions must be implemented to reduce air pollution and to improve air quality.

  6. Toxoplasma Gondii Infection and Depression: A Case-Control Seroprevalence Study.

    PubMed

    Alvarado-Esquivel, Cosme; Sánchez-Anguiano, Luis Francisco; Hernández-Tinoco, Jesús; Berumen-Segovia, Luis Omar; Torres-Prieto, Yazmin Elizabeth; Estrada-Martínez, Sergio; Pérez-Álamos, Alma Rosa; Ortiz-Jurado, María Nalleli; Molotla-de-León, Gabriel; Beristain-García, Isabel; Rábago-Sánchez, Elizabeth; Liesenfeld, Oliver

    2016-06-24

    We assessed the association of Toxoplasma gondii infection and depression in a sample of psychiatric patients and control subjects without depression. We performed an age- and gender-matched case-control study of 89 patients suffering from depression attended in a public psychiatric hospital in Durango City, Mexico and 356 control subjects without depression from the general population of the same city. Participants were tested for the presence of anti-Toxoplasma IgG and IgM antibodies using enzyme-linked immunoassays. Anti-T. gondii IgG antibodies were found in 11 (12.4%) of the 89 cases and in 22 (6.2%) of the 356 controls (OR = 2.14; 95% CI: 1.00-4.59; P = 0.04). Anti-T. gondii IgM antibodies were found in four (19%) of 21 anti-T. gondii IgG seropositive controls but not in 11 anti-T. gondii IgG seropositive cases (P = 0.27). Patients aged 30 years old and younger had a significantly higher seroprevalence of T. gondii infection than controls of the same age group (P = 0.001). Results of the present study suggest a potential association between T. gondii infection and depression. Furthers studies to confirm our results and to determine the epidemiology of T. gondii in young depressed patients should be conducted.

  7. Do nurses really care? Confirming the stereotype with a case control study.

    PubMed

    Williams, Geraint; Dean, Phil; Williams, Elisabeth

    In their definition of modern nursing, the Royal College of Nursing emphasizes the importance of caring. However, there is little other than anecdotal evidence that female qualified staff nurses are more caring and compassionate than average individuals. A study was carried out to test, under scientific conditions with a case control study, the hypothesis that staff nurses are no more caring than average female individuals. Using the ten-item personality inventory (TIPI) questionnaire, a statistical comparison was made between 174 volunteer female staff nurses and data for 760 adult female controls extracted from the TIPI instrument's original validation study. The questionnaire measures each of the five major facets of personality: openness, extroversion, conscientiousness, agreeableness and neuroticism. Agreeableness, which is a tendency to be compassionate, considerate and cooperative, was used as a proxy measure for 'caring'. Data were analysed using unpaired Student's t-tests. Female staff nurses recorded significantly higher scores than female controls concerning the personality traits extroversion, agreeableness, conscientiousness and emotional stability (P<0.05). The analysis demonstrates that in direct comparison to normal adult females, staff nurses are significantly more caring, conscientious and resilient individuals. The personality traits found in female staff nurses complement their profession and to some extent justify the caring, compassionate nurse stereotype. Whether career nursing self-selects these qualities or to what extent nursing staff develop aspects of their personality as a product of experience is a subject for debate.

  8. The Relationship between Iron Deficiency and Febrile Convulsion: A Case-Control Study

    PubMed Central

    Sharif, Mohammad Reza; Kheirkhah, Davood; Madani, Mahla; Kashani, Hamed Haddad

    2016-01-01

    Introduction: Febrile seizure is among the most common convulsion disorders in children, which strikes 2% to 5% of children between 3 to 60 months of age. Some studies have reported that iron deficiency could be a risk factor for febrile seizure. The present study was conducted to compare the rate of iron deficiency anemia in febrile children with and without seizure. Materials and Methods: This case-control study evaluated 200 children aged 6-60 month in two 100 person groups (febrile seizure and febrile without convulsion) in Kashan. The CBC diff, serum iron and TIBC were done for all of participants. Diagnosis of iron deficiency anemia based on mentioned tests. Results: No significant differences were found in two groups regarding to the age, gender, and the disease causing the fever. The presence of iron deficiency anemia was 45% in the convulsion group and 22% in the group with fever without convulsion. The Chi Square test indicated a significant difference between two groups. Conclusions: The findings suggest that a considerable percentage of children having febrile seizure suffer from iron-deficiency anemia and low serum iron. This means the low serum iron and presence of anemia can serve as a reinforcing factor for the febrile seizure in children. PMID:26383191

  9. Factors associated with syphilis infection: a comprehensive analysis based on a case-control study.

    PubMed

    Xiao, Y; Li, S-L; Lin, H-L; Lin, Z-F; Zhu, X-Z; Fan, J-Y; Gao, K; Zhang, H-L; Lin, L-R; Liu, L-L; Tong, M-L; Niu, J-J; Yang, T-C

    2016-04-01

    This study aimed to comprehensively evaluate factors that influence the likelihood of syphilis infection from risk-taking behaviours and medical conditions. A retrospective case-control study was conducted by enrolling 664 syphilis inpatients (excluding 11 congenital syphilis patients) and 800 sex- and age-matched controls. Medical histories, clinical data and patient interview data were collected and subjected to logistic regression analyses. The prevalence of syphilis in the study population was 3·9% (675/17,304). By univariate analysis, syphilis infection was associated with migration between cities, marital status, smoking, reproductive history, hypertension, elevated blood urea nitrogen (BUN) and infection with hepatitis B virus (HBV) (P < 0·05). A high rate of syphilis-HBV co-infection was observed in HIV-negative patients and further research revealed an association between syphilis and specific HBV serological reactivity. Syphilis was also associated with the frequency, duration and status of tobacco use. Multivariate analysis indicated that syphilis infection was independently associated with migration between cities [adjusted odds ratio (aOR) 1·368, 95% confidence interval (CI) 1·048-1·785], current smoking (aOR 1·607, 95% CI 1·177-2·195), elevated BUN (aOR 1·782, 95% CI 1·188-2·673) and some serological patterns of HBV infection. To prevent the spread of infectious diseases, inpatients and blood donors should be tested for HIV, syphilis, HBV and HCV simultaneously.

  10. Antiviral immunity following smallpox virus infection: a case-control study.

    PubMed

    Hammarlund, Erika; Lewis, Matthew W; Hanifin, Jon M; Mori, Motomi; Koudelka, Caroline W; Slifka, Mark K

    2010-12-01

    Outbreaks of smallpox (i.e., caused by variola virus) resulted in up to 30% mortality, but those who survived smallpox infection were regarded as immune for life. Early studies described the levels of neutralizing antibodies induced after infection, but smallpox was eradicated before contemporary methods for quantifying T-cell memory were developed. To better understand the levels and duration of immunity after smallpox infection, we performed a case-control study comparing antiviral CD4(+) and CD8(+) T-cell responses and neutralizing antibody levels of 24 smallpox survivors with the antiviral immunity observed in 60 smallpox-vaccinated (i.e., vaccinia virus-immune) control subjects. We found that the duration of immunity following smallpox infection was remarkably similar to that observed after smallpox vaccination, with antiviral T-cell responses that declined slowly over time and antiviral antibody responses that remained stable for decades after recovery from infection. These results indicate that severe, potentially life-threatening disease is not required for the development of sustainable long-term immunity. This study shows that the levels of immunity induced following smallpox vaccination are comparable in magnitude to that achieved through natural variola virus infection, and this may explain the notable success of vaccination in eradicating smallpox, one of the world's most lethal diseases.

  11. Case-control study of skin cancer in the rubber industry

    SciTech Connect

    Bourguet, C.C.

    1983-01-01

    A case-control study of non-melanoma skin cancer was conducted in two companies of the American rubber manufacturing industry. The study goal was to examine the association of basal and squamous cell carcinoma with seven raw materials: carbon black, dustless, extender, and lubricating oils, waxes, solvents, and the rubber stock itself. Study members were white males belonging to predefined cohorts of rubber workers. Cases were identified from hospital pathology department records. Each case was matched with four controls of the same company, and year of birth and hire (+/- one year). Company A provided 31 cases (22 squamous cell carcinoma cases) and 118 controls. Company B provided 55 cases (43 squamous cell cases) and 216 controls. Exposure was estimated using employee personnel records. In Company A, squamous cell carcinoma was associated with rubber stock, lubricating oils, and non-polycyclic chemicals. Ten years of moderate rubber stock exposure multiplied the existing relative risk by 2.96 (95% CL: 1.06-8.23). Exposure to non-polycyclic chemicals carried a relative risk of 5.5 (1.28-23.48). These chemicals are used as accelerators, antioxidants, and antiozonants. Disease was negatively associated with extender oil exposure. In Company B, jobs with heat exposure (milling, extruding, and curing) were associated with disease. Using a second control group, matched on year of birth, there was no convincing evidence that cases had longer employment duration than controls. This does not suggest an overall skin cancer risk among rubber workers.

  12. A Case-Control Study on the Risk Factors for Meningococcal Disease among Children in Greece

    PubMed Central

    Hadjichristodoulou, Christos; Mpalaouras, George; Vasilopoulou, Vasiliki; Katsioulis, Antonios; Rachiotis, George; Theodoridou, Kalliopi; Tzanakaki, Georgia; Syriopoulou, Vassiliki; Theodoridou, Maria

    2016-01-01

    Purpose The aim of this study was to identify environmental or genetic risk factors that are associated with invasive meningococcal disease (IMD) in children in Greece. Methods A case-control study was performed in 133 children (44 cases and 89 controls) aged between 0–14 years, who were hospitalized in a children's hospital in Athens. Demographics and possible risk factors were collected by the use of a structured questionnaire. To investigate the association of mannose binding lectin (MBL) with IMD, a frequency analysis of the haplotypes of the MBL2 gene and quantitative measurement of MBL serum protein levels were performed using Nanogen NanoChipR 400 technology and immuno-enzyme techniques, respectively. Results The multivariate analysis revealed that changes in a child's life setting (relocation or vacation, OR = 7.16), paternal smoking (OR = 4.51), upper respiratory tract infection within the previous month (OR = 3.04) and the density of people in the house/100m2 (OR = 3.16), were independent risk factors associated with IMD. Overall 18.8% of patients had a MBL2 genotype with low functionality compared to 10.1% of healthy controls, but this was not statistically significant (p = 0.189). Conclusion Prevention strategies aimed at reducing parental smoking and other risk factors identified in this study could decrease the risk of IMD among children in Greece. PMID:27351742

  13. Case-control association study of WLS variants in opioid and cocaine addicted populations.

    PubMed

    Crist, Richard C; Ambrose-Lanci, Lisa M; Zeng, Angela; Yuan, Cindy; Kampman, Kyle M; Pettinati, Helen M; Oslin, David W; O'Brien, Charles P; Ferraro, Thomas N; Doyle, Glenn A; Lohoff, Falk W; Berrettini, Wade H

    2013-06-30

    The opioid receptor family is involved in the development and maintenance of drug addiction. The mu-opioid receptor (MOR) mediates the rewarding effects of multiple drugs, including opiates and cocaine. A number of proteins interact with MOR, potentially modulating MOR function and altering the physiological consequences of drug use. These mu-opioid receptor interacting proteins (MORIPs) are potential therapeutic targets for the treatment of addiction. The Wntless (WLS) protein was recently identified as a MORIP in a yeast two-hybrid screen. In this study, we conducted a case-control association analysis of 16 WLS genetic variants in opioid and cocaine addicted individuals of both African-American (opioid n=336, cocaine n=908) and European-American (opioid n=335, cocaine n=336) ancestry. Of the analyzed SNPs, three were nominally associated with opioid addiction and four were nominally associated with cocaine addiction. None of these associations were significant following multiple testing correction. These data suggest that the common variants of WLS analyzed in this study are not associated with opioid or cocaine addiction. However, this study does not exclude the possibilities that rare variants in WLS may affect susceptibility to drug addiction, or that common variants with small effect size may fall below the detection level of our analysis.

  14. Lung cancer risks of underground miners: cohort and case-control studies

    SciTech Connect

    Archer, V.E.

    1988-05-01

    All underground mines have higher radon levels than are found in surface air. Ventilation is the primary method of controlling radon levels. Fourteen cohort and seven case-control studies done on underground miners are reviewed; they include many types of ore. Only five of the studies deal with more than 100 lung cancer deaths. Variations in the attributable risk are given. Some generalizations can be drawn from these studies: the longer the follow-up, the greater is the attributable risk, even though the relative risk is reasonably constant. The induction-latent period is quite variable but is shortened by high exposure rates, by cigarette smoking, and by increasing age at start of mining. The predominant histological type of lung cancer among miners changed from small-cell undifferentiated for short follow-up time to epidermoid after long follow-up times. With short follow-up time, a multiplicative interaction between smoking and radiation was indicated, but, with long follow-up time, the two factors appear to be simply additive. This difference is probably due to the shortened latent period among cigarette smokers, not to synergism. 36 references.

  15. Nested case-control study of lung cancer among chemical workers

    SciTech Connect

    Bond, G.G.; Flores, G.H.; Shellenberger, R.J.; Cartmill, J.B.; Fishbeck, W.A.; Cook, R.R.

    1986-07-01

    A recent cohort mortality study of 19,608 male employees of a major Texas chemical production facility had suggested that they might be at higher risk of lung cancer compared with the male population of the United States or Texas but not with the male population of the five-county area in which they reside. An occupational exposure was a possible explanation for this pattern, and a nested case-control study was undertaken of the 308 lung cancer deaths observed between 1940 and 1981. Two control groups, one a decedent and the other a ''living'' series, were individually matched to cases one-for-one. Interviews were conducted with subjects or their next of kin to collect information on smoking and other potential confounders. These data were combined with employee work history records and industrial hygiene data to form the basis of the analyses. Traditional stratification methods and conditional logistic regression were employed to examine for effect modification and to control confounding. Statistically significant, positive and negative associations were found for assignment to several work areas within the facility. Suggestive associations were observed for exposure to sulfur dioxide and heat. These and additional associations are discussed relative to evidence from other studies.

  16. Habitual Sleep Deprivation is Associated with 
Type 2 Diabetes: A Case-Control Study

    PubMed Central

    Al-Abri, Mohammed A.; Jaju, Deepali; Al-Sinani, Sawsan; Al-Mamari, Ali; Albarwani, Sulayma; Al-Resadi, Khalid; Bayoumi, Riyadh; Hassan, Mohammed; Al-Hashmi, Khamis

    2016-01-01

    Objectives It is suggested that a minimum of eight hours of sleep per night is needed for metabolism to work normally. The aim of the study was to determine the association of habitual sleep deprivation and type 2 diabetes mellitus (T2DM). Methods We conducted a case-control study comparing patients with T2DM with age and sex matched healthy controls. Standard sleep questionnaires (the Berlin and Epworth Sleepiness Scale) and a weekly diary were used by patients to self-report habitual sleep. Results A total of 172 diabetics and 188 healthy controls were enrolled in the study. There was a significant difference between T2DM and healthy controls in nocturnal sleep duration (p = 0.033). There was a significant association between nocturnal sleep duration of fewer than six hours and T2DM (χ2 = 14.0; p = 0.0001). There was no significant difference in daytime sleepiness and daytime naps between the T2DM and control groups (p = 0.452; p = 0.581, respectively). Conclusions A nocturnal sleep duration < 6 hours is associated with T2DM. PMID:27974953

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

    SciTech Connect

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

    1993-12-01

    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.

  18. Case-control study of multiple myeloma with special reference to diet as risk factor.

    PubMed

    Vlajinac, H D; Pekmezović, T D; Adanja, B J; Marinković, J M; Kanazir, M S; Suvajdzić, N D; Colović, M D

    2003-01-01

    The case-control study was conducted in Belgrade (Yugoslavia) during the period 1994-1998. The objective of the study was to investigate factors related to the occurrence of multiple myeloma (MM). The study group consisted of 100 newly diagnosed MM patients and the same number of matched hospital controls. In the analysis conditional univariate and multivariate logistic regression were applied. According to multivariate analysis the following factors were significantly related to MM: smoking > or =25 cigarettes per day (Odds ratio--OR=6.7, 95% confidence interval--95% CI=1.3-34.3); having more than two brothers (OR=2.7, 95% CI=1.3-5.3), rheumatoid arthritis in personal history (OR=4.2, 95% CI=1.2-14.8), and frequent (4-7 times per week vs. lower frequency) consumption of yogurt (OR=3.1, 95% CI=1.6-6.0) and vegetables (OR=0.4, 95% CI=0.1-1.0).

  19. A Matched Case-Control Study of Risk Factors for Breast Cancer Risk in Vietnam

    PubMed Central

    Nguyen, J.; Le, Q. H.; Duong, B. H.; Sun, P.; Pham, H. T.; Ta, V. T.; Kotsopoulos, J.; Narod, S. A.

    2016-01-01

    Background. Vietnam has a low age-standardized incidence of breast cancer, but the incidence is rising rapidly with economic development. We report data from a matched case-control study of risk factors for breast cancer in the largest cancer hospital in Vietnam. Methods. 492 incident breast cancer cases unselected for family history or age at diagnosis and 1306 control women age 25–75 were recruited from the National Cancer Hospital (BVK), Hanoi. Structured interviews were conducted and pathology data was centrally reported at the National Cancer Hospital of Vietnam, in Hanoi. Results. Our analysis included 294 matched pairs. Mean age at diagnosis was 46.7 years. Lower mean parity, older age at first parity, increasing weight and BMI at age 18, and increasing BMI at diagnosis were positively correlated with breast cancer cases compared to controls. Age at first menarche and duration of breastfeeding were not statistically different between cases and controls. Conclusions. In this study we demonstrate that breast cancer in Vietnam is associated with some but not all of the published risk factors from Western populations. Our data is consistent with other studies of breast cancer in Asian populations. PMID:28070424

  20. Surgical glove perforation among nurses in ophthalmic surgery: a case-control study.

    PubMed

    Shek, Karen Mei-Yan; Chau, Janita Pak-Chun

    2014-04-01

    Many of the ophthalmic surgical instruments are extremely fine and sharp. Due to the dim light environment required for ophthalmic surgical procedures, the passing of sharp instruments among surgeons and scrub nurses also poses a risk for glove perforations. A case-control study was performed to determine the number and site of perforations in the surgical gloves used by a group of scrub nurses during ophthalmic surgery. All six nurses working in an eye and refractive surgery centre in Hong Kong participated in the study. A total of 100 (50 pairs) used surgical gloves were collected following 50 ophthalmic surgeries. Fifty pairs of new surgical gloves were also collected. Every collected surgical glove underwent the water leak test. The surgical procedure perforation rate was 8%, and none of the perforations were detected by the scrub nurses. No perforations were found in any unused gloves. The findings indicate that glove perforations for scrub nurses during ophthalmic surgery do occur and mostly go unnoticed. Future studies should continue to explore factors contributing to surgical glove perforation.

  1. Adjusting for bias due to incomplete case ascertainment in case-control studies of birth defects.

    PubMed

    Howards, Penelope P; Johnson, Candice Y; Honein, Margaret A; Flanders, W Dana

    2015-04-15

    Case-control studies of birth defects might be subject to selection bias when there is incomplete ascertainment of cases among pregnancies that are terminated after a prenatal diagnosis of the defect. We propose a simple method to estimate inverse probability of selection weights (IPSWs) for cases ascertained from both pregnancies that end in termination and those that do not end in termination using data directly available from the National Birth Defects Prevention Study and other published information. The IPSWs can then be used to adjust for selection bias analytically. We can also allow for uncertainty in the selection probabilities through probabilistic bias analysis. We provide an illustrative example using data from National Birth Defects Prevention Study (1997-2009) to examine the association between prepregnancy obesity (body mass index, measured as weight in kilograms divided by height in meters squared, of ≥30 vs. <30) and spina bifida. The unadjusted odds ratio for the association between prepregnancy obesity and spina bifida was 1.48 (95% confidence interval: 1.26, 1.73), and the simple selection bias-adjusted odds ratio was 1.26 (95% confidence interval: 1.04, 1.53). The probabilistic bias analysis resulted in a median adjusted odds ratio of 1.22 (95% simulation interval: 0.97, 1.47). The proposed method provides a quantitative estimate of the IPSWs and the bias introduced by incomplete ascertainment of cases among terminated pregnancies conditional on a set of assumptions.

  2. A stepwise likelihood ratio test procedure for rare variant selection in case-control studies.

    PubMed

    Kuk, Anthony Y C; Nott, David J; Yang, Yaning

    2014-04-01

    There is much recent interest in finding rare genetic variants associated with various diseases. Owing to the scarcity of rare mutations, single-variant analyses often lack power. To enable pooling of information across variants, we use a random effect formulation within a retrospective modeling framework that respects the retrospective data collecting mechanism of case-control studies. More concretely, we model the control allele frequencies of the variants as random effects, and the systematic differences between the case and control frequencies as fixed effects, resulting in a mixed model. The use of Poisson approximation and gamma-distributed random effects results in a generalized negative binomial distribution for the joint distribution of the control and case frequencies. Variants are selected by conducting stepwise likelihood ratio tests. The superiority of the proposed method over two existing variant selection methods is demonstrated in a simulation study. The effects of non-gamma random effects and correlated variants are also found to be not too detrimental in the simulation study. When the proposed procedure is applied to identify rare variants associated with obesity, it identifies one additional variant not picked up by existing methods.

  3. Relationship between Temporomandibular Disorders, Widespread Palpation Tenderness and Multiple Pain Conditions: A Case - Control Study

    PubMed Central

    Chen, Hong; Slade, Gary; Lim, Pei Feng; Miller, Vanessa; Maixner, William; Diatchenko, Luda

    2012-01-01

    The multiple bodily pain conditions in temporomandibular disorders (TMD) have been associated with generalized alterations in pain processing. The purpose of this study was to examine the relationship between the presence of widespread body palpation tenderness (WPT) and the likelihood of multiple comorbid pain conditions in TMD patients and controls. This case-control study was conducted in 76 TMD subjects with WPT, 83 TMD subjects without WPT, and 181 non-TMD matched control subjects. The study population was also characterized for clinical pain, experimental pain sensitivity, and related psychological phenotypes. Results showed that (1) TMD subjects reported an average of 1.7 comorbid pain conditions compared to 0.3 reported by the control subjects (p<0.001); (2) Compared to control subjects, the odds ratio (OR) for multiple comorbid pain conditions is higher for TMD subjects with WPT [OR 8.4 (95% CI 3.1–22.8) for TMD with WPT versus OR 3.3 (95% CI 1.3–8.4) for TMD without WPT]; (3) TMD subjects with WPT presented with reduced pressure pain thresholds (PPTs) in both cranial and extra-cranial regions compared to TMD subjects without WPT; and (4) TMD subjects with WPT reported increased somatic symptoms. These findings suggest that pain assessment outside of the orofacial region may prove valuable for the classification, diagnosis, and management of TMD patients. PMID:23031401

  4. Quality of life in patients with hand eczema as health promotion: a case control study.

    PubMed

    Ghaderi, Reza; Saadatjoo, Alireza

    2014-01-01

    Health promotion has been defined by the World Health Organization's (WHO) 2005 Bangkok Charter for Health Promotion as "the process of enabling people to increase control over their health and its determinants, and thereby improve their health". One of the most important determinants of health is quality of life. Hand eczema is a common skin disease that can adversely affect the quality of life of patients. The aim of this study was to determine the quality of life in patients with hand eczema. This case-control study was performed on 70 patients with hand eczema and 70 healthy controls. All the patients filled out two questionnaires: Short Form 36 (SF-36) and Dermatology Life Quality index (DLQI). The data were analyzed using the statistical software package for social sciences (SPSS). The mean score score of quality of life in dimensions of physical functioning, vitality, and general health in the SF-36 was lower compared to the control group. The mean score in DLQI in patients with hand eczema was 8.68. There was a significant negative correlation between the scores of different dimensions of QOL obtained in the two questionnaires (SF36 and DLQI). The study demonstrated that the quality of life in patients with hand eczema was lower than that of controls. It seems advisable that psychiatric consultations or psychotherapy be included in the treatment of chronic hand eczema.

  5. Risk Factors for Preeclampsia in Women from Colombia: A Case-Control Study

    PubMed Central

    Reyes, Laura M.; García, Ronald G.; Ruiz, Silvia L.; Camacho, Paul A.; Ospina, Maria B.; Aroca, Gustavo; Accini, Jose L.; López-Jaramillo, Patricio

    2012-01-01

    Background Preeclampsia (PE) is a multi-causal disease characterized by the development of hypertension and proteinuria in the second half of pregnancy. Multiple risk factors have been associated with the development of PE. Moreover, it is known that these risk factors vary between populations from developed and developing countries. The aim of this study is to identify which risk factors are associated with the development of preeclampsia (PE) among Colombian women. Methods A multi-centre case-control study was conducted between September 2006 and July 2009 in six Colombian cities. Cases included women with PE (n = 201); controls were aged-matched pregnant women (n = 201) without cardiovascular or endocrine diseases for a case-control ratio of 1∶1. A complete medical chart, physical examination and biochemical analysis were completed before delivery. Multivariable logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI) of potential risk factors associated with PE. Results The presence of factors present in the metabolic syndrome cluster such as body mass index >31 Kg/m2 (OR = 2.18; 1.14–4.14 95% CI), high-density lipoprotein <1.24 mmol/L (OR = 2.42; 1.53–3.84 95% CI), triglycerides >3.24 mmol/L (OR = 1.60; 1.04–2.48 95% CI) and glycemia >4.9 mmol/L (OR = 2.66; 1.47–4.81 95%CI) as well as being primigravidae (OR = 1.71; 1.07–2.73 95% CI) were associated with the development of PE, after adjusting for other variables. Conclusion Factors present in the cluster of metabolic syndrome and primigravidity were associated with a greater risk of PE among Colombian women. Understanding the role of this cluster of risk factors in the development of PE is of crucial importance to prevent PE and remains to be determined. PMID:22911827

  6. Bovine Viral Diarrhoea Virus (BVDV) in Dairy Cattle: A Matched Case-Control Study.

    PubMed

    Machado, G; Egocheaga, R M F; Hein, H E; Miranda, I C S; Neto, W S; Almeida, L L; Canal, C W; Stein, M C; Corbellini, L G

    2016-02-01

    Bovine viral diarrhoea virus (BVDV) causes one of the most important diseases of cattle in terms of economic costs and welfare. The aims were to estimate herd prevalence and to investigate the factors associated with antibodies in bulk tank milk (BTM) in dairy herds through a matched case-control study. To estimate herd prevalence, BTM samples were randomly selected (n = 314) from a population (N = 1604). The true prevalence of BVDV was 24.3% (CI 95% = 20.1-29.3%). For the case-control study, BVDV antibody-positive herds (high antibody titres) were classified as cases (n = 21) and matched (n = 63) by milk production with herds presenting low antibody titres (ratio of 1 : 3). Three multivariable models were built: 1) full model, holding all 21 variables, and two models divided according to empirical knowledge and similarity among variables; 2) animal factor model; and 3) biosecurity model. The full model (model 1) identified: age as a culling criteria (OR = 0.10; CI 95% = 0.02-0.39; P < 0.01); farms that provided milk to other industries previously (OR = 4.13; CI 95% = 1.17-14.49; P = 0.02); and isolation paddocks for ill animals (OR = 0.14; CI 95% = 0.01-0.26; P = 0.02). The biosecurity model revealed a significant association with the use of natural mating (OR = 9.03; CI 95% = 2.14-38.03; P < 0.01); isolation paddocks for ill animals (OR = 0.06; CI 95% = 0.05-0.83; P = 0.03); years providing milk for the same industry (OR = 0.94; CI 95% = 0.91-0.97; P = 0.02); and direct contact over fences among cattle of neighbouring farms (OR = 5.78; CI 95% = 1.41-23.67; P = 0.04). We recommend the application of grouping predictors as a good choice for model building because it could lead to a better understanding of disease-exposure associations.

  7. An apple a day may hold colorectal cancer at bay: recent evidence from a case-control study.

    PubMed

    Jedrychowski, Wieslaw; Maugeri, Umberto

    2009-01-01

    Environmental factors play an important role in the etiology of colorectal cancer, the second-most common malignancy in both genders in developed countries. Evidence has shown that potential cancer-inducing oxidative damage might be prevented or restricted largely by the presence of dietary antioxidants of plant origin, such as fruits or vegetables. The protective antioxidant effect of fruits and vegetables has been attributed to flavonoids, a major class of phytochemicals naturally occurring in fruits, vegetables, and various foods of plant origin. Yet, epidemiologic cohort studies relating flavonoid intake to risk of colorectal cancer have been sparse and inconclusive. Apples are a rich source of flavonoids and have the second highest level of antioxidant power among all fruits, with peels having a stronger antioxidant activity than apple flesh. A recent reanalysis of several case-control studies in Italy demonstrated a consistent inverse association between apple consumption and the risk of various cancers, and among them ofcolorectal cancer. Here we assessed the potential protective impact of apples on risk of colorectal cancer in the course of a recently performed hospital-based case-control study in a country with dietary habits very different from those of Mediterranean region. The results showed that highest risk of colorectal cancer was among older persons and those who were residents of villages or small towns. The risk of colorectal cancer was inversely correlated with daily number of apple servings, but the most significant reductions of OR estimates were observed for an intake one or more apple servings daily (OR = 0.37, 95% CI: 0.15-0.91). No other fruit was significantly associated with altering the risk of colorectal cancer.

  8. The Mortality Penalty of Incarceration: Evidence from a Population-based Case-control Study of Working-age Males.

    PubMed

    Pridemore, William Alex

    2014-06-01

    There is a growing body of research on the effects of incarceration on health, though there are few studies in the sociological literature of the association between incarceration and premature mortality. This study examined the risk of male premature mortality associated with incarceration. Data came from the Izhevsk (Russia) Family Study, a large-scale population-based case-control design. Cases (n = 1,750) were male deaths aged 25 to 54 in Izhevsk between October 2003 and October 2005. Controls (n = 1,750) were selected at random from a city population register. The key independent variable was lifetime prevalence of incarceration. I used logistic regression to estimate mortality odds ratios, controlling for age, hazardous drinking, smoking status, marital status, and education. Seventeen percent of cases and 5 percent of controls had been incarcerated. Men who had been incarcerated were more than twice as likely as those who had not to experience premature mortality (odds ratio = 2.2, 95 percent confidence interval: 1.6-3.0). Relative to cases with no prior incarceration, cases who had been incarcerated were more likely to die from infectious diseases, respiratory diseases, non-alcohol-related accidental poisonings, and homicide. Taken together with other recent research, these results from a rigorous case-control design reveal not only that incarceration has durable effects on illness, but that its consequences extend to a greater risk of early death. I draw on the sociology of health literature on exposure, stress, and social integration to speculate about the reasons for this mortality penalty of incarceration.

  9. Use of hair colouring products and breast cancer risk: a case-control study in Connecticut.

    PubMed

    Zheng, T; Holford, T R; Mayne, S T; Owens, P H; Boyle, P; Zhang, B; Zhang, Y W; Zahm, S H

    2002-08-01

    This case-control study was designed to test the hypothesis that the risk of breast cancer varies by type and colour of the hair colouring products used. A total of 608 cases and 609 controls were included in the study. We found no increased risk associated with the overall use of hair dye products or exclusive use of permanent or temporary types of hair dye products. Among those who reported to have exclusively used semi-permanent types of hair colouring products, some of the ORs were elevated. However, none of the ORs related to age at first use, duration of use, total number of applications, and years since first use, was statistically significant. There was also no increased risk of breast cancer associated with exclusive use of dark or light hair colouring products, or use of mixed types or colours of hair dye products. We also found no increased risk of breast cancer associated with hair dye use based on an individual's reason for using a hair colouring product, such as to cover grey or to change natural hair colour. These data suggest that the use of hair colouring products does not have a major impact on the risk of breast cancer.

  10. Dietary Inflammatory Index and Risk of Colorectal Cancer: A Case-Control Study in Korea.

    PubMed

    Cho, Young Ae; Lee, Jeonghee; Oh, Jae Hwan; Shin, Aesun; Kim, Jeongseon

    2016-07-30

    The role of diet-associated inflammation in colorectal cancer is of interest. Accordingly, we aimed to examine whether the dietary inflammatory index (DII) was associated with the risk of colorectal cancer in a case-control study conducted in Korea. The DII was based on dietary intake, which was determined by a 106-item semi-quantitative food frequency questionnaire completed by 923 colorectal cancer cases and 1846 controls. Logistic regression was used to estimate odd ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses were conducted by the anatomical site of the cancer, sex, and other risk factors. Higher DII scores were associated with an increased incidence of colorectal cancer (OR (95% CI) = 2.16 (1.71, 2.73) for highest vs. lowest tertile). The magnitude differed by anatomical site and sex. This association was slightly weaker in subjects with proximal colon cancer (1.68 (1.08, 2.61)) and was stronger in women (2.50 (1.64, 3.82)). Additionally, stronger associations were observed in subjects who were older than 50 years (p for interaction = 0.004) and engaged in physical activity (p for interaction < 0.001). Results from this study suggest that diet-associated inflammation may increase the risk of colorectal cancer, and this effect may differ by certain factors, such as anatomical site, age, sex, and lifestyle.

  11. Diet, living conditions and nasopharyngeal carcinoma in Tunisia--a case-control study.

    PubMed

    Jeannel, D; Hubert, A; de Vathaire, F; Ellouz, R; Camoun, M; Ben Salem, M; Sancho-Garnier, H; de-Thé, G

    1990-09-15

    We conducted a case-control study of nasopharyngeal carcinoma (NPC) in Tunisia, on diet, dietary patterns and life style, the characteristics of which had been defined by an anthropological study. Eighty incident cases, diagnosed in Tunisia between November 1986 and November 1987, were each matched for sex, age and place of residence to 2 controls. The subjects were asked for dietary data referring to the year preceding the diagnosis of NPC and, with help of their families, during childhood and after weaning. After adjustment for an empirical living conditions score, the following food items were found to be associated with an increased risk for NPC: preserved spiced meat (quaddid), basic stewing preparation (mixture of red and black pepper, garlic, oil, caraway and coriander), and harissa (red pepper, olive oil, garlic, caraway, salt) taken with bread as a snack during childhood and youth. Moreover, subjects who had been directly weaned from mother's milk on to an adult diet were found to be at higher risk for NPC.

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

    PubMed

    Yousefichaijan, Parsa; Sharafkhah, Mojtaba; Salehi, Bahman; Rafiei, Mohammad

    2016-01-01

    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.

  13. A case-control study of lung cancer at a foundry and two engine plants.

    PubMed

    Austin, H; Delzell, E; Lally, C; Rotimi, C; Oestenstad, K

    1997-04-01

    A nested case-control study of lung cancer was conducted among workers at an iron foundry and two engine manufacturing plants whose lung cancer mortality rates were slightly higher than expected. The study included 231 lung cancer cases and 408 controls for whom complete work histories were obtained. There was no association between usual plant of employment and lung cancer mortality. The odds ratio for persons employed for 20 or more years in the foundry compared with persons employed in the engine plants was 0.90 (95% confidence interval: 0.55, 1.5). Long-term employment as an engine plant worker was associated with odds ratios slightly, but not statistically significantly, below unity. In the foundry, only usual employment in the material handling departmental group and any employment in the quality control departmental group were statistically significantly directly related to lung cancer risk. However, the number of subjects so employed was small and there was no dose-response relation between length of employment in these departmental groups and lung cancer risk. Cases were less frequently employed than were controls in engine plant machining and assembly jobs and departments. It is concluded that employment in this facility was either unrelated, or only weakly related, to lung cancer risk.

  14. Invasive Fungal Rhinosinusitis versus Bacterial Rhinosinusitis with Orbital Complications: A Case-Control Study

    PubMed Central

    Thanaviratananich, Sanguansak

    2013-01-01

    Background. Invasive fungal rhinosinusitis with orbital complications (IFSwOC) is a life-threatening condition. The incidence of mortality has been reported to be up to 80 percent. This study was conducted to determine the risk factors, presentations, clinical, and imaging findings that could help to manage this condition promptly. Methods. We conducted a case-control study of 100 patients suffering from rhinosinusitis with orbital complications. The risk factors, clinical presentations, radiological findings, medical and surgical managements, durations of hospital stay, and mortality rate data were collected. Results. Sixty-five patients were diagnosed with IFSwOC, while the other thirty-five patients composed the control group. The most important risk factor for IFSwOC was diabetes mellitus. Visual loss and diplopia were the significant symptom predictors. The significant clinical predictors were nasal crust, oculomotor nerve, and optic nerve involvement. The CT findings of IFSwOC were sinus wall erosion and hyperdensity lesions. The mortality rate was 25.71 percent in the IFSwOC group and 3.17 percent in the control group. Conclusions. Invasive fungal rhinosinusitis with orbital complications is symptomatic of a high mortality rate. The awareness of a patient's risk factors, the presenting symptoms, signs of fungal invasion, and aggressive management will determine the success of any treatment procedures. PMID:24298218

  15. A Case-control Study on Risk Factors for Severe Hand, Foot and Mouth Disease

    PubMed Central

    Zhang, Dingmei; Li, Ruolin; Zhang, Wangjian; Li, Guowei; Ma, Zhanzhong; Chen, Xiashi; Du, Zhicheng; Li, Zhiyuan; Guo, Pi; Lin, Zhuochen; Lu, Jiahai; Hao, Yuantao

    2017-01-01

    The objective of this study was to identify potential risk factors for severe hand, foot and mouth disease (HFMD). In this case-control study, 459 severe HFMD patients and 246 mild HFMD patients from Guangdong province and Henan province, China were included. Data comprising demographic characteristics, clinical symptoms and signs, laboratory findings and other factors were collected. Univariate analysis revealed 30 factors associated with severe cases. Further multivariate analysis indicated four independent risk factors: fatigue (p < 0.01, odd ratio [OR] = 204.7), the use of glucocorticoids (p = 0.03, OR = 10.44), the use of dehydrant drugs (p < 0.01, OR = 73.7) and maculopapular rash (p < 0.01, OR = 84.4); and one independent protective factor: herpes or ulcers in mouth (p = 0.01, OR = 0.02). However, more systematic research and validation are needed to understand the underlying risk factors for severe HFMD. PMID:28084311

  16. A case-control study of ultraviolet radiation exposure, vitamin D, and lymphoma risk in adults

    PubMed Central

    Kelly, Jennifer L.; Friedberg, Jonathan W.; Calvi, Laura M.; van Wijngaarden, Edwin; Fisher, Susan G.

    2010-01-01

    Recent research suggests that ultraviolet radiation exposure (UVRE), our major source of vitamin D, is associated with reduced lymphoma risk. Animal and human studies support an association between vitamin D (vitD) insufficiency and increased risk of some malignancies. We conducted a clinic-based case-control study (140 lymphoma cases, 139 controls; 2002–2005, Rochester, NY) to evaluate UVRE and vitD insufficiency in relation to lymphoma risk. Subjects completed a survey and provided a blood sample. We used multivariable logistic regression to estimate lymphoma risk in relation to past (5–10 years prior) UVRE and current vitD insufficiency (determined by serum 25(OH)D). Possible differences in effect by lymphoma subtype were explored, but statistical power was limited. We confirmed the previously reported decrease in lymphoma risk with past UVRE, specifically sunbathing (>once/week versus never); adjusted odds ratio (ORadj), = 0.28, 95% confidence interval (CI): 0.10–0.79. Current vitD insufficiency was not associated with lymphoma risk (ORadj=0.89, 95% CI: 0.47–1.72). However, current sunbathing frequency was correlated with measured serum 25(OH)D values. Therefore, while our data do not support an association with current vitD status, development of accurate methods for past vitD assessment to further investigate its role in the association between past UVRE and lymphoma risk is warranted. PMID:20373010

  17. Case-control study of cancer among Du Pont employees with potential for exposure to dimethylformamide

    SciTech Connect

    Walrath, J.; Fayerweather, W.E.; Gilby, P.G.; Pell, S.

    1989-05-01

    This case-control study was undertaken to determine whether the risk of developing cancers of the buccal cavity and pharynx (N = 39), liver (N = 6), prostate (N = 43), testis (N = 11), or malignant melanoma of the skin (N = 39) is related to exposure to dimethylformamide (DMF). Case and control subjects were obtained from four Du Pont plants. DMF is produced at one plant and used at the other three. Cancer cases identified from the company Cancer Registry comprise those reported among active male employees at the study plants during 1956 to 1985. For each case, two control subjects were selected, matched on sex, payroll class (wage or salary), birth year, and plant. To determine whether an employee could have been exposed to DMF during his career at the plant, all jobs with potential for exposure to DMF were identified. Each job was assigned an exposure ranking based on DMF industrial hygiene air monitoring, DMF metabolite (measured as N-methylformamide in urine) monitoring, and knowledge of the evolution of manufacturing processes and workplace exposure controls. Each employee's DMF exposure pattern was then characterized as (a) ever v never having been exposed to DMF and (b) highest DMF exposure experienced. Summary analyses for all plants combined showed no statistically significant association between ever having been exposed to DMF and subsequent development of cancers of the buccal cavity and pharynx, liver, malignant melanoma, prostate, and testis. Examined by plant site, prostate cancer at one plant was significantly elevated, based on three case subjects exposed out of four.

  18. A case-control study of the clinical diagnosis and course of Lassa fever.

    PubMed

    McCormick, J B; King, I J; Webb, P A; Johnson, K M; O'Sullivan, R; Smith, E S; Trippel, S; Tong, T C

    1987-03-01

    A prospective case-control study of Lassa fever was established in Sierra Leone to measure the frequency and case-fatality ratio of Lassa fever among febrile hospital admissions and to better delineate the clinical diagnosis and course of this disease. Lassa fever was responsible for 10%-16% of all adult medical admissions and for approximately 30% of adult deaths in the two hospitals studied. The case-fatality ratio for 441 hospitalized patients was 16.5%. We found the best predictor of Lassa fever to be the combination of fever, pharyngitis, retrosternal pain, and proteinuria (predictive value together, .81); of outcome, the best predictor was the combination of fever, sore throat, and vomiting (relative risk of death, 5.5). Complications included mucosal bleeding (17%), bilateral or unilateral eighth-nerve deafness (4%), and pleural (3%) or pericardial (2%) effusion. Lassa fever is endemic in this area and is a more-common cause of hospital admission and death than has previously been described; this disease must be considered when diagnosing febrile illness in West Africa.

  19. Zinc Status Biomarkers and Cardiometabolic Risk Factors in Metabolic Syndrome: A Case Control Study

    PubMed Central

    Freitas, Erika P. S.; Cunha, Aline T. O.; Aquino, Sephora L. S.; Pedrosa, Lucia F. C.; Lima, Severina C. V. C.; Lima, Josivan G.; Almeida, Maria G.; Sena-Evangelista, Karine C. M.

    2017-01-01

    Metabolic syndrome (MS) involves pathophysiological alterations that might compromise zinc status. The aim of this study was to evaluate zinc status biomarkers and their associations with cardiometabolic factors in patients with MS. Our case control study included 88 patients with MS and 37 controls. We performed clinical and anthropometric assessments and obtained lipid, glycemic, and inflammatory profiles. We also evaluated zinc intake, plasma zinc, erythrocyte zinc, and 24-h urinary zinc excretion. The average zinc intake was significantly lower in the MS group (p < 0.001). Regression models indicated no significant differences in plasma zinc concentration (all p > 0.05) between the two groups. We found significantly higher erythrocyte zinc concentration in the MS group (p < 0.001) independent from co-variable adjustments. Twenty-four hour urinary zinc excretion was significantly higher in the MS group (p = 0.008), and adjustments for age and sex explained 21% of the difference (R2 = 0.21, p < 0.001). There were significant associations between zincuria and fasting blood glucose concentration (r = 0.479), waist circumference (r = 0.253), triglyceride concentration (r = 0.360), glycated hemoglobin concentration (r = 0.250), homeostatic model assessment—insulin resistance (r = 0.223), and high-sensitivity C-reactive protein concentration (r = 0.427) (all p < 0.05) in the MS group. Patients with MS had alterations in zinc metabolism mainly characterized by an increase in erythrocyte zinc and higher zincuria. PMID:28241426

  20. Cancer of the nose and paranasal sinuses in the metal industry: a case-control study.

    PubMed

    Comba, P; Barbieri, P G; Battista, G; Belli, S; Ponterio, F; Zanetti, D; Axelson, O

    1992-03-01

    The association between nasal cancer and work in the metal industry was investigated in a case-control study located in the province of Brescia, north eastern Italy. Thirty five cases of malignant epithelial neoplasms of the nasal cavity and paranasal sinuses who were resident in the province of Brescia and diagnosed or treated by the ear, nose, and throat department and the radiotherapy unit (Centro Alte Energie) of the Brescia Hospital in the years 1980-9 were included in the study. Controls (102) were patients affected by benign and malignant neoplasms of the head and neck who were resident in the Brescia Province and matched the cases by age and sex. All the subjects were interviewed by telephone. Metal workers showed an increased risk of nasal cancer (odds ratio (OR) 3.1; 90% confidence interval (90% CI) 0.48-20); a higher risk was associated with work in foundries (OR 5.9; 90 CI 0.77-46). Work in wood, leather, and textile industries was also associated with increased risk of nasal cancer.

  1. A case-control study of cancer of the nose and paranasal sinuses and occupational exposures.

    PubMed

    Comba, P; Battista, G; Belli, S; de Capua, B; Merler, E; Orsi, D; Rodella, S; Vindigni, C; Axelson, O

    1992-01-01

    The association between nasal cancer and various occupations was investigated in a case-control study in the provinces of Verona and Vicenza (northeastern Italy) and Siena (central Italy). Cases of malignant epithelial neoplasm of the nasal cavities and paranasal sinuses diagnosed in the years 1982-1987 in the hospitals of Verona, Legnago, Bussolengo, Vicenza, and Siena comprised the study. Controls were patients admitted to the same hospitals as the cases, with any diagnosis except chronic rhino-sinusal disease and nasal bleeding. Age, gender, residency, and date of admission were taken into account by matching. Cases and controls, or their next of kin, were interviewed or required to fill in a mailed questionnaire; the overall response rate was 70%. Altogether, 78 cases and 254 controls provided information on occupational history. Significantly increased risks were associated (in males) with work in the wood industry (odds ratio [O.R.]: 5.8; 90% confidence interval [C.I.]: (2.2-16) and in the leather industry (6.8; 1.9-25). Textile workers, furnacemen, construction workers, and workers with possible exposure to organic dusts showed increased risks even if statistical significance was not reached.

  2. Melasma and its association with different types of nevi in women: A case-control study

    PubMed Central

    Adalatkhah, Hassan; Sadeghi-bazargani, Homayoun; Amini-sani, Nayereh; Zeynizadeh, Somayeh

    2008-01-01

    Background Very little is known about possible association of nevi and melasma. The study objective was to determine if there is an association between melasma and existence of different kinds of nevi. Methods In a case-control study, 120 female melasma patients referred to dermatology clinic of Ardabil and 120 patients referred to other specialty clinics who lacked melasma were enrolled after matching for age. Number of different types of nevi including lentigines and melanocytic nevi were compared between case and control group patients. Data were entered into the computer and analyzed by SPSS 13 statistical software. Results Mean number of lentigines was 25.5 in melasma group compared to 8 in control group(P < 0.01). Mean number of melanocytic nevi was 13.2 in cases compared to 2.8 in control group(P < 0.001). Multivariate analysis showed that existence of freckles, lentigines and more than three melanocytic nevi were positively related to developing melasma. The chance of melasma increased up to 23 times for patients having more than three melanocytic nevi. Congenital nevi were observed among 10% both in case and control groups. Campbell de morgan angiomas were seen among 26 patients(21.8%) in case group compared to 6 patients(5%) in control group. Conclusion Existence of lentigines and melanocytic nevi increases chance of having melasma PMID:18680608

  3. Breast Cancer Risk Factors among Ugandan Women at a Tertiary Hospital: A Case-Control Study

    PubMed Central

    Galukande, Moses; Wabinga, Henry; Mirembe, Florence; Karamagi, Charles; Asea, Alexzander

    2016-01-01

    Background Although East Africa, like other countries in sub-Saharan Africa, has a lower incidence of breast cancer than high-income countries, the disease rate is rising steeply in Africa; it has nearly tripled in the past few decades in Uganda. There is a paucity of studies that have examined the relation between reproductive factors and breast cancer risk factors in Ugandan women. Objective To determine breast cancer risk factors among indigenous Ugandan women. Methods This is a hospital-based unmatched case-control study. Interviews were conducted between 2011 and 2012 using structured questionnaires. Patients with histologyproven breast cancer were recruited over a 2-year period. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results A total of 350 women were recruited; 113 were cases and 237 were controls. The mean age was 47.5 years (SD 14) for the cases and 45.5 years (SD 14.1) for the controls. The odds of breast cancer risk seemed lower for those who breastfed (adjusted OR = 0.04; 95% CI: 0.01, 0.18). There was no significance for early age at first full-term birth (adjusted OR = 1.96; 95% CI: 0.97, 3.96; p = 0.061), and urban residence carried no increased odds of breast cancer either (p = 0.201). Conclusion Breastfeeding seems to be associated with reduced odds of breast cancer. PMID:27104645

  4. A Case-Control Study on the Oxidative Balance of 50% Autologous Serum Eye Drops

    PubMed Central

    Marinho, Diane; Zelanis, Samira; Belló-Klein, Adriane; Locatelli, Claudete; Nicola, Felipe; Kunzler, Ana Laura; Fernandes, Tania Regina Gatelli; Carraro, Cristina Campos; Barbosa, Luciene

    2016-01-01

    Importance. Autologous serum (AS) eye drops are recommended for severe dry eye in patients with ocular surface disease. No description of the antioxidant balance of AS eye drops has been reported in the literature. Objective. This study sought to evaluate the total reactive antioxidant potential (TRAP) and concentration of reactive oxygen species (ROS) in samples of 50% AS eye drops and their correlations with the demographic characteristics and lifestyle habits of patients with ocular surface disease and healthy controls. Design. This was a case-control study with a 3-month follow-up period. Participants. 16 patients with severe dry eye disease of different etiologies and 17 healthy controls matched by age, gender, and race were included. Results. TRAP and ROS were detected at all evaluated times. There were no differences in the mean ROS (p = 0.429) or TRAP (p = 0.475) levels between cases and controls. No statistically significant differences in the concentrations of ROS or TRAPs were found at 0, 15, or 30 days (p for ROS = 0.087 and p for TRAP = 0.93). Neither the demographic characteristics nor the lifestyle habits were correlated with the oxidative balance of the 50% AS eye drops. Conclusions and Relevance. Both fresh and frozen 50% AS eye drops present antioxidant capacities and ROS in an apparently stable balance. Moreover, patients with ocular surface disease and normal controls produce equivalent AS eye drops in terms of oxidative properties. PMID:27635188

  5. Role of Platelet Parameters on Sudden Sensorineural Hearing Loss: A Case-Control Study in Iran

    PubMed Central

    2016-01-01

    Sudden sensorineural hearing loss (SSNHL) is a common otological disorder characterized by a hearing loss greater than 30 dB over three consecutive frequencies, in less than 72 hours. It has been established that platelet parameters, such as mean platelet volume, are associated with ischemic heart events, whose clinical manifestations are similar to those of SSNHL. Hence, we aimed to determine if the platelet count, mean platelet volume and platelet distribution width are related to the occurrence and severity of sudden sensorineural hearing loss. A case-control prospective study was conducted in a teaching hospital in Iran. One hundred-eight patients with SSNHL and an equal number of healthy, age- and sex-matched controls were enrolled in the study. Peripheral venous blood samples were collected from the subjects, and the platelet count, mean platelet volume and platelet distribution width were measured with an automated blood cell counter. Analysis of the audiometry and hematological test results using SPSS22 software showed no statistical correlation between the platelet parameters and the occurrence of SSNHL, but correlation coefficients showed a significant correlation between PDW and hearing loss severity in patients group. However, further investigation is required to unequivocally establish the absence of correlation between the platelet parameters and occurrence of SSNHL. PMID:26829393

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

    PubMed

    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.

  7. Robotic versus laparoscopic sacrocolpopexy for apical prolapse: a case-control study

    PubMed Central

    CUCINELLA, G.; CALAGNA, G.; ROMANO, G.; DI BUONO, G.; GUGLIOTTA, G.; SAITTA, S.; ADILE, G.; MANZONE, M.; ACCARDI, G.; PERINO, A.; AGRUSA, A.

    2016-01-01

    The apical prolapse has always been considered the most complex of the defects of the pelvic floor, for both the difficulty of the surgical corrective technique and for the high post-surgical recurrence rate. Today, the laparoscopic sacrocolpopexy can be considered the standard treatment for apical prolapse. In the last years, several author performed robotic sacrocolpopexy, obtaining positive results. So, we developed a case-control study in order to compare the surgical outcome of robotic group with a control group of laparoscopic approach in patients with symptomatic apical pro-lapsed between January 2015 and December 2015 at University Hospital Policlinico “P. Giaccone” and Ospedali Riuniti “Villa Sofia-Cervello”, Palermo. Our experience shows that robotic sacrocolpopexy can be considered in positive way for clinical results obtained: all procedures were executed with no complications, we noted a lower intraoperative blood loss and a shorter hospital stay than in laparoscopic group. Although the mean operative time and the economic costs are higher in robotic surgery, this study demonstrates that the use of robotic platform for repairing of symptomatic apical vaginal prolapse is feasible, safe and associated with short-term satisfactory results, representing therefore a valid alternative to laparoscopic approach. PMID:27734794

  8. The relation between seborrheic keratoses and malignant solid tumours. A case-control study.

    PubMed

    Grob, J J; Rava, M C; Gouvernet, J; Fuentes, P; Piana, L; Gamerre, M; Sarles, J C; Bonerandi, J J

    1991-01-01

    In order to establish whether or not here is an association between cancer and intense growth of seborrheic keratosis, the so-called Leser-Trelat sign, we conducted a case control study in which the number and features of seborrheic keratosis in 82 patients with recent solid tumours, were compared with 82 age- and sex-matched controls. Neither numbers nor features of seborrheic keratosis differed significantly in patients and controls. Eruptive seborrheic keratosis was noted in only one patient and one control. This study showed that solid malignancies are not generally associated with an increase in the number or size of seborrheic keratosis lesions, thus suggesting that they are not controlled by a hypothetical secretion of growth factors by tumours. Our results suggest that Leser-Trelat is either a coincidence, or at most a very rare sign of unusual types of cancer. We also showed that multiple cherry angiomas, previously reported to be a paraneoplastic sign, are not regularly associated with solid tumours.

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

    SciTech Connect

    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.

  10. Case-control study of lung cancer and truck driving in the Teamsters Union

    SciTech Connect

    Steenland, N.K.; Silverman, D.T.; Hornung, R.W. )

    1990-06-01

    We conducted a case-control study of lung cancer deaths in the Teamsters Union to compare the risk of different occupations within the teamsters, after controlling for smoking and other confounders. Occupations with no presumed exposure to diesel fumes were used as the nonexposed group. The study population consisted of 996 cases and 1,085 controls who had died in 1982-83 after applying for pensions. Next of kin provided information on smoking, work history, and other potential confounders. Work history data were also obtained from the Teamsters Union. While no single job category had a significant excess risk compared to the non-exposed group, certain sub-groups were elevated. The odds ratio for those with long-term employment as long-haul truckers after 1959 (an approximate date for the introduction of diesel engines) was 1.55 (95% CI: 0.97, 2.47). Long-term drivers of primarily diesel trucks had an odds ratio of 1.89 (95% CI: 1.04, 3.42). Overall, our results suggest that diesel truck drivers have an excess risk of lung cancer compared to other teamsters in jobs outside the trucking industry. However, our findings were not uniformly consistent and our data have many limitations, the most important of which is the lack of data on exposure to diesel fumes.

  11. Case-control study on the prevention of occupational eye injuries.

    PubMed

    Ho, Chi-Kung; Yen, Ya-Lin; Chang, Cheng-Hsien; Chiang, Hung-Che; Shen, Ying-Ying; Chang, Po-Ya

    2008-01-01

    The risk factors for occupational eye injuries have never been published in Taiwan. We conducted a case-control study to analyze the differences among workers on their knowledge, attitude to and practice (KAP) of occupational accident prevention. In the study, a statistical model was also set up for predicting the occupational problem. Subjects, including 31 cases of work-related eye injuries and 62 controls, completed a structured questionnaire on KAP, which revealed that 80.6% and 62.7% of workers in the case and control groups, respectively, did not wear eye protection during work. Furthermore, we found that temporary employment (OR, 10.7; 95% CI, 3.03-36.16) and fewer than 10 years of education (OR, 4.44; 95% CI, 1.73-11.44) were the major risk factors for occupational eye injuries. In addition, we developed a logistic regression model with four predictors (temporary employment, education years less than 10, poor management of industrial health and safety in the workplace, and poor attitude towards accident prevention) for the occurrence of occupational eye injuries. In conclusion, in Taiwan, compulsory regulation of wearing eye protection during work, good education, management of work safety and hygiene and employee (especially temporary worker) commitment to safety and health are strongly recommended prevention strategies.

  12. Lower limb venous insufficiency and tobacco smoking: a case-control study.

    PubMed

    Gourgou, Sophie; Dedieu, Florence; Sancho-Garnier, Hélène

    2002-06-01

    At the present time, no study has yet clearly established whether tobacco smoking is a risk factor of lower limb venous insufficiency. This case-control study was initiated in France to determine the possible etiologic relation between tobacco smoking and lower limb venous insufficiency. A total of 1,806 cases suffering from lower limb venous insufficiency, recruited by 460 general practitioners between April 1997 and April 1998, were matched by age and gender to 1,806 controls. Data were collected on the physical examination, medical reason for consulting, current treatments, smoking habits, and known risk factors of lower limb venous insufficiency. Conditional logistic regression for the statistical analyses was performed. Known risk factors of lower limb venous insufficiency were confirmed in the overall model: family history of venous insufficiency (odds ratio (OR) = 7.7), frequent (OR = 1.4) or regular (OR = 2.7) prolonged standing at work, heat exposure (OR = 2.0), low physical activity (OR = 1.6), and (for women) more than four pregnancies (OR = 3.4). Multivariate analysis adjusted for other risk factors showed that lower limb venous insufficiency is significantly associated with tobacco smoking (OR = 1.7 for 10-19 cigarettes/day and OR = 2.4 for 20 cigarettes/day or more; p < 0.001). These results suggest that smoking is significantly associated with lower limb venous insufficiency, in accordance with biologic data and physiopathologic mechanisms.

  13. Risk Factors for Sporadic Pancreatic Neuroendocrine Tumors: A Case-Control Study

    PubMed Central

    Ben, Qiwen; Zhong, Jie; Fei, Jian; Chen, Haitao; Yv, Lifen; Tan, Jihong; Yuan, Yaozong

    2016-01-01

    The current study examined risk factors for sporadic pancreatic neuroendocrine tumors (PNETs), including smoking, alcohol use, first-degree family history of any cancer (FHC), and diabetes in the Han Chinese ethnic group. In this clinic-based case-control analysis on 385 patients with sporadic PNETs and 614 age- and sex-matched controls, we interviewed subjects using a specific questionnaire on demographics and potential risk factors. An unconditional multivariable logistic regression analysis was used to estimate adjusted odds ratios (AORs). No significant differences were found between patients and controls in terms of demographic variables. Most of the patients with PNETs had well-differentiated PNETs (G1, 62.9%) and non-advanced European Neuroendocrine Tumor Society (ENETS) stage (stage I or II, 83.9%). Ever/heavy smoking, a history of diabetes and a first-degree FHC were independent risk factors for non-functional PNETs. Only heavy drinking was found to be an independent risk factor for functional PNETs (AOR = 1.87; 95% confidence interval [CI], 1.01–3.51). Ever/heavy smoking was also associated with advanced ENETS staging (stage III or IV) at the time of diagnosis. This study identified first-degree FHC, ever/heavy smoking, and diabetes as risk factors for non-functional PNETs, while heavy drinking as a risk factor for functional PNETs. PMID:27782199

  14. Occupational exposures and non-Hodgkin's lymphoma: Canadian case-control study

    PubMed Central

    Karunanayake, Chandima P; McDuffie, Helen H; Dosman, James A; Spinelli, John J; Pahwa, Punam

    2008-01-01

    Background The objective was to study the association between Non-Hodgkin's Lymphoma (NHL) and occupational exposures related to long held occupations among males in six provinces of Canada. Methods A population based case-control study was conducted from 1991 to 1994. Males with newly diagnosed NHL (ICD-10) were stratified by province of residence and age group. A total of 513 incident cases and 1506 population based controls were included in the analysis. Conditional logistic regression was conducted to fit statistical models. Results Based on conditional logistic regression modeling, the following factors independently increased the risk of NHL: farmer and machinist as long held occupations; constant exposure to diesel exhaust fumes; constant exposure to ionizing radiation (radium); and personal history of another cancer. Men who had worked for 20 years or more as farmer and machinist were the most likely to develop NHL. Conclusion An increased risk of developing NHL is associated with the following: long held occupations of faer and machinist; exposure to diesel fumes; and exposure to ionizing radiation (radium). The risk of NHL increased with the duration of employment as a farmer or machinist. PMID:18687133

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

    PubMed Central

    2016-01-01

    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. PMID:27156346

  16. Child pedestrian and bicyclist injuries: results of community surveillance and a case-control study.

    PubMed Central

    Kraus, J. F.; Hooten, E. G.; Brown, K. A.; Peek-Asa, C.; Heye, C.; McArthur, D. L.

    1996-01-01

    OBJECTIVES: To describe the dimensions of childhood pedestrian and bicyclist injuries in Long Beach, California, and to identify risk factors for these injuries. POPULATION: Long Beach residents aged 0-14 years who were involved in an auto versus pedestrian or bicyclist incident that resulted in a hospital visit and/or police response, between 1 September 1988 and 31 August 1990. METHODS: Cases were identified retrospectively using hospital charts, police records, and coroner's reports; demographic, clinical, and situational information were abstracted from the same. A nested case-control study was conducted to examine the street environments where children were injured, and to identify environmental risk factors at these case sites. RESULTS: 288 children comprised the sample population. Midblock dart-outs emerged as the single most common type of incident. Most incidents happened on residential streets, but the risk of injury was greatest on larger boulevards, and tended to cluster by region within the city. Adjusted odds ratios show that case sites had a larger proportion of traffic exceeding posted speed limits, and were also four times more likely to be near a convenience store, gas station, or fast food store than control sites. CONCLUSIONS: The findings of this study suggest three possible routes for the prevention of childhood pedestrian and bicyclist injuries: education, law enforcement, and environmental modification. PMID:9346093

  17. Predictive factors of death in patients with tuberculosis: a nested case-control study.

    PubMed

    Moosazadeh, M; Nezammahalleh, A; Movahednia, M; Movahednia, N; Khanjani, N; Afshari, M

    2015-06-09

    Tuberculosis is one of the main causes of death worldwide. This study aimed to determine predictive factors for death in patients with tuberculosis to set priorities for public heath interventions to reduce mortality in these patients. This nested case-control study was carried out in Mazandaran province of Islamic Republic of Iran among tuberculosis patients who were treated during 2002-2009. Each deceased patient was individually matched with a control patient according to sex, age, area of involvement and time of follow-up. Potential risk factors for death were evaluated using multivariate conditional logistic regression models. From 2206 patients 376 cases and 376 matched controls were selected. Only positive serology for HIV (OR = 19.1), history of kidney disease (OR = 6.81) and use of immunosuppressant drugs (OR = 3.96) significantly increased the risk of death in tuberculosis patients. These potentially modifiable risk factors could be taken into account in preventive interventions for tuberculosis patients in our country.

  18. Alcohol and new onset atrial fibrillation: a case-control study of a current series.

    PubMed Central

    Koskinen, P; Kupari, M; Leinonen, H; Luomanmäki, K

    1987-01-01

    The aetiological role of alcohol in new onset atrial fibrillation was evaluated in a case-control study of 100 consecutive patients aged 21-64 years. Clinical examination, routine diagnostic tests, and echocardiography revealed an underlying disease or other identifiable factor for atrial fibrillation in 65 patients (group 1); 35 patients had idiopathic atrial fibrillation (group 2). The most common diseases associated with atrial fibrillation were ischaemic heart disease (21%), hypertension (13%), and cardiomyopathy (8%). Data on alcohol consumption were obtained by interviewing the patients and their age and sex matched controls on admission. The mean daily alcohol intake of group 2 patients during the week preceding atrial fibrillation was significantly larger than that of either controls or group 1 patients. Compared with controls significantly more patients in both groups with atrial fibrillation had consumed alcohol within two days of the onset of the arrhythmia. Significantly more patients had onset of arrhythmia on Wednesday, Thursday, or Friday than on any other weekday, including patients with high alcohol intake. This study establishes alcohol as an important precipitating factor for new onset atrial fibrillation. PMID:3593617

  19. Postural changes in women with chronic pelvic pain: a case control study

    PubMed Central

    Montenegro, Mary LLS; Mateus-Vasconcelos, Elaine CL; Rosa e Silva, Júlio C; dos Reis, Francisco J Candido; Nogueira, Antonio A; Poli-Neto, Omero B

    2009-01-01

    Background Chronic pelvic pain (CPP) is a lower abdominal pain lasting at least 6 months, occurring continuously or intermittently and not associated exclusively with menstruation or intercourse. Although the musculoskeletal system has been found to be involved in CPP, few studies have assessed the contribution of posture in women with CPP. We aimed to determine if the frequency of postural changes was higher in women with CPP than healthy subjects. Methods A case-control study included 108 women with CPP of more than 6 months' duration (CPP group) who consecutively attended at the Hospital of the University of São Paulo and 48 healthy female volunteers (control group). Postural assessment was noninvasive and performed in the standing position, with the reference points of Kendall used as normal parameters. Factors associated with CPP were assessed by logistic regression analysis. Results Logistic regression showed that the independent factors associated with CPP were postural changes in the cervical spine (OR 4.1; 95% CI 1.6–10.7; p < 0.01) and scapulae (OR 2.9; 95% CI 1.1–7.6; p < 0.05). Conclusion Musculoskeletal changes were associated with CPP in 34% of women. These findings suggest that a more detailed assessment of women with CPP is necessary for better diagnosis and for more effective treatment. PMID:19583850

  20. Risk Factors for Primary Pulmonary TB in Almaty Region, Kazakhstan: A Matched Case-Control Study

    PubMed Central

    ZHUSSUPOV, Baurzhan; HERMOSILLA, Sabrina; TERLIKBAYEVA, Assel; AIFAH, Angela; MA, Xin; ZHUMADILOV, Zhaxybay; ABILDAYEV, Tleukhan; DARISHEVA, Meruyert; BERIKKHANOVA, Kulzhan

    2016-01-01

    Background: This study examined the association between incident pulmonary tuberculosis (TB) and social and behavioral characteristics in Almaty Oblast, Kazakhstan from 2012 to 2013. Methods: We used a matched case-control design to estimate the role of factors for acquiring pulmonary TB. Totally 324 individuals were recruited from Sep 2012 to Mar 2013. Participants included 110 TB index cases with newly detected pulmonary TB. Each case was matched with one household and one community control. A total of 107 household and 107 community controls were included to the study. Adjusted odds ratios measuring associations between TB and risk factors were calculated by using a conditional multiple logistic regression analysis. Results: TB cases were more likely to be younger, recent smokers and have diabetes, when compared to household controls. Between TB cases and community controls, TB was significantly associated with age, non-married family status, living in a rented home, recent smoker, and having diabetes. Comparing TB cases with community controls, we found that foreign birth was marginally associated with incident TB case status. Conclusion: Our findings confirm the role of modifiable risk factors for TB in Kazakhstan; highlighting the importance of developing interventions addressing social determinants and proximate risk factors for high TB burden regions. PMID:27252913

  1. A Case-Controlled Study of Altered Visual Art Production in Alzheimer’s and FTLD

    PubMed Central

    Rankin, Katherine P.; Liu, Anli A.; Howard, Sara; Slama, Hilary; Hou, Craig. E.; Shuster, Karen; Miller, Bruce L.

    2009-01-01

    Objective To characterize dementia-induced changes in visual art production. Background While case studies show altered visual artistic production in some patients with neurodegenerative disease, no case-controlled studies have quantified this phenomenon across groups of patients. Method Forty-nine subjects [18 Alzheimer’s disease (AD), 9 Frontotemporal Dementia (FTD), 9 Semantic Dementia (SD), 15 healthy older controls (NC)] underwent formal neuropsychological testing of visuospatial, perceptual, and creative functioning, and produced four drawings. Subjective elements of drawings were rated by an expert panel that was blind to diagnosis. Results Despite equal performance on standard visuospatial tests, dementia groups produced distinct patterns of artistic features that were significantly different from NCs. FTDs used more disordered composition and less active mark-making (p<0.05). Both FTDs and SDs drawings were rated as more bizarre and demonstrated more facial distortion than NCs (p<0.05). Also, SDs drastically failed a standardized test of divergent creativity. ADs artwork was more similar to controls than to FTDs or SDs, but showed a more muted color palette (p<0.05) and trends toward including fewer details, less ordered compositions, and occasional facial distortion. Conclusions These group differences in artistic style likely resulted from disease-specific focal neurodegeneration, and elucidate the contributions of particular brain regions to the production of visual art. PMID:17356345

  2. Childhood Leukemia and 50 Hz Magnetic Fields: Findings from the Italian SETIL Case-Control Study

    PubMed Central

    Salvan, Alberto; Ranucci, Alessandra; Lagorio, Susanna; Magnani, Corrado

    2015-01-01

    We report on an Italian case-control study on childhood leukemia and exposure to extremely low frequency magnetic fields (ELF-MF). Eligible for inclusion were 745 leukemia cases, aged 0–10 years at diagnosis in 1998–2001, and 1475 sex- and age-matched population controls. Parents of 683 cases and 1044 controls (92% vs. 71%) were interviewed. ELF-MF measurements (24–48 h), in the child’s bedroom of the dwelling inhabited one year before diagnosis, were available for 412 cases and 587 controls included in the main conditional regression analyses. The magnetic field induction was 0.04 μT on average (geometric mean), with 0.6% of cases and 1.6% of controls exposed to >0.3 μT. The impact of changes in the statistical model, exposure metric, and data-set restriction criteria was explored via sensitivity analyses. No exposure-disease association was observed in analyses based on continuous exposure, while analyses based on categorical variables were characterized by incoherent exposure-outcome relationships. In conclusion, our results may be affected by several sources of bias and they are noninformative at exposure levels >0.3 μT. Nonetheless, the study may contribute to future meta- or pooled analyses. Furthermore, exposure levels among population controls are useful to estimate attributable risk. PMID:25689995

  3. Do early skin care practices alter the risk of atopic dermatitis? A case-control study

    PubMed Central

    Rendell, Marla E.; Baig-Lewis, Shahana F.; Berry, Trista M.; Denny, Melissa E.; Simpson, Brenda M.; Brown, Peter A.; Simpson, Eric L.

    2012-01-01

    Background The rise in atopic dermatitis prevalence seen in industrialized countries in unexplained. Some authors have suggested that the increase in the use of skin care products is partly responsible. There are few studies examining skin care practices commonly used in treatment of children. We hypothesized that the use of moisturizers early in life may alter the risk for developing atopic dermatitis. Methods A case-control study utilizing two control groups was performed. Cases were defined as children under six years of age who developed atopic dermatitis. A normal control and a high-risk control group were used for comparison. Parents or caregivers of children were questioned regarding skin care practices used in early life in an attempt to identify practices that increased the risk of developing atopic dermatitis. Results The regular use of a moisturizer on the child during the first six months of life was very common in all groups, 76%, 74.7%, and 78% in the atopic, non-atopic, and high-risk groups, respectively. Because of the high rate of moisturizer use in all groups, no significant differences were found between groups. Watery lotions were the most commonly used moisturizer. Conclusions Despite published guidelines advising to the contrary, the regular use of moisturizers was common in this population. Although no one specific skin care practice was associated with atopic dermatitis, the frequent use of products potentially detrimental to the skin barrier raises concern. PMID:21895755

  4. Excessive sleep need following traumatic brain injury: a case-control study of 36 patients.

    PubMed

    Sommerauer, Michael; Valko, Philipp O; Werth, Esther; Baumann, Christian R

    2013-12-01

    Increased sleep need following traumatic brain injury, referred to in this study as post-traumatic pleiosomnia, is common, but so far its clinical impact and therapeutic implications have not been characterized. We present a case-control study of 36 patients with post-traumatic pleiosomnia, defined by an increased sleep need of at least 2 h per 24 h after traumatic brain injury, compared to 36 controls. We assessed detailed history, sleep-activity patterns with sleep logs and actigraphy, nocturnal sleep with polysomnography and daytime sleep propensity with multiple sleep latency tests. Actigraphy recordings revealed that traumatic brain injury (TBI) patients had longer estimated sleep durations than controls (10.8 h per 24 h, compared to 7.3 h). When using sleep logs, TBI patients underestimated their sleep need. During nocturnal sleep, patients had higher amounts of slow-wave sleep than controls (20 versus 13.8%). Multiple sleep latency tests revealed excessive daytime sleepiness in 15 patients (42%), and 10 of them had signs of chronic sleep deprivation. We conclude that post-traumatic pleiosomnia may be even more frequent than reported previously, because affected patients often underestimate their actual sleep need. Furthermore, these patients exhibit an increase in slow-wave sleep which may reflect recovery mechanisms, intrinsic consequences of diffuse brain damage or relative sleep deprivation.

  5. A case-control study of dietary factors in patients with lung cancer.

    PubMed

    Huang, C; Zhang, X; Qiao, Z; Guan, L; Peng, S; Liu, J; Xie, R; Zheng, L

    1992-09-01

    A case-control study was designed to investigate association of dietary factors with the risk of lung cancer in Sichuan, China. The cases consisted of 135 patients with preinvasive lung cancer which had been confirmed with histopathology, fiber bronchoscope, CT and X-ray film in three provincial hospitals in the recent one year. Controls were healthy subjects who went to one of these hospitals for health check-up; patients with pulmonary diseases was excluded. Controls were matched to cases for sex and age with a ratio of 1:1. Nutrient intakes, the eating habit and other relevant factors were investigated. The data analyzed with the conditional logistic regression model indicated that dietary beta-carotene intakes had a significantly inverse association with the risk of lung cancer. Vitamin C had a less significantly inverse association with the risk. Association of protein, fat, energy, retinol intakes or diet-balance index with the risk was not significant. Association of tea, alcohol, garlic or mushroom, respectively, with the risk was also not observed. Consumption of more processed foods and deep-fried foods were found to be risk factors. Smoking and air pollution from coal burning stoves were also observed as independent risk factors of lung cancer in the present study. The mental stress incidence in the case was significantly higher than that in the control.

  6. A case-control study of bladder cancer in the United States rubber and tyre industry.

    PubMed Central

    Checkoway, H; Smith, A H; McMichael, A J; Jones, F S; Monson, R R; Tyroler, H A

    1981-01-01

    A case-control study of bladder cancer was conducted in five United States rubber and tyre companies to determine if there were high-risk jobs and work areas within the industry. The study included 220 male cases of bladder cancer, of whom 107 were identified from hospital record reviews and 113 from death certificates. Each case was matched individually with two industry controls by sex, race, year of birth, and company. One control was matched additionally by year of hire and duration of employment. Comparisons of cases and controls not matched by year of hire and age of hire showed no differences for those variables, which suggests that age and calendar period of first exposure to the industry were not risk determinants. When the work histories of both cases and controls were contrasted it was found that cases were more likely than controls to have worked in milling (odds ratio (OR) = 1.91) and calender operation (OR = 2.21) jobs. The relative risk estimates for milling and calender operation both exhibited linear trends of increase with duration of exposure. Milling and calender operation jobs entail potential exposures to volatilised reaction products from heated rubber stock. A better understanding of aetiological associations with job type will require more detailed characterisation of the work environment with regard to the sources and levels of aromatic amines and other suspected bladder carcinogens. PMID:7272236

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

    PubMed

    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 < 0.05) among Neospora seropositive cows. In conclusion, the finding discloses the strong association of N. caninum with reproductive disorders compared to 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.

  8. Psychosocial Stress and Risk of Myocardial Infarction: A Case-Control Study in Belgrade (Serbia)

    PubMed Central

    Vujcic, Isidora; Vlajinac, Hristina; Dubljanin, Eleonora; Vasiljevic, Zorana; Matanovic, Dragana; Maksimovic, Jadranka; Sipetic, Sandra

    2016-01-01

    Background The purpose of this study was to investigate which psychosocial risk factors show the strongest association with occurrence of myocardial infarction (MI) in the population of Belgrade in peacetime, after the big political changes in Serbia. Methods A case-control study was conducted involving 154 consecutive newly diagnosed patients with MI, and 308 controls matched by gender, age, and place of residence. Results According to conditional logistic regression analysis, after adjustment for conventional coronary risk factors, the odds ratios (95% confidence intervals) for work-related stressful events, financial stress, deaths and diseases, and general stress were 3.78 (1.83-7.81), 3.80 (1.96-7.38), 1.69 (1.03-2.78), and 3.54 (2.01-6.22), respectively. Among individual stressful life events, the following were independently related to MI: death of a close family member, 2.21 (1.01-4.84); death of a close friend, 42.20 (3.70-481.29); major financial problems, 8.94 (1.83-43.63); minor financial problems, 4.74 (2.02-11.14); changes in working hours, 4.99 (1.64-15.22); and changes in working conditions, 30.94 (5.43-176.31). Conclusions During this political transition period , stress at work, financial stress, and stress in general as they impacted the population of Belgrade, Serbia were strongly associated with occurence of MI. PMID:27274168

  9. High Prevalence of Metabolic Syndrome in Patients with Discoid Lupus Erythematosus: A Cross-Sectional, Case-Control Study

    PubMed Central

    Akarsu, Sevgi; Semiz, Fatma; Aktan, Sebnem

    2017-01-01

    Although it is known that systemic form of lupus erythematosus (LE) and metabolic syndrome (MetS) are frequently observed together, there are no published reports on MetS in patients with skin-restricted LE. We aimed to compare the frequencies of MetS and its components in discoid LE (DLE) with the non-DLE control group. Additionally, we intended to determine the differences of sociodemographic and clinical data of the DLE patients with MetS compared to the patients without MetS. This was a cross-sectional, case-control study, including 60 patients with DLE and 82 age- and gender-matched control subjects. In DLE group, the presence of MetS was observed as more frequent (48.3% versus 24.4%, p = 0.003), and hypertriglyceridemia (43.3% versus 22.0%, p = 0.006) and reduced HDL-cholesterol (61.7% versus 23.2%, p < 0.001) among the MetS components were found significantly higher when compared to the control group. DLE patients with MetS were at older age (50.45 ± 11.49 versus 43.06 ± 12.09, p = 0.02), and hypertension, hyperlipidemia/dyslipidemia, and cardiovascular disease histories were observed at a higher ratio when compared to the patients without MetS. Between the DLE patients with and without MetS, no significant difference was observed in terms of clinical characteristics of DLE. Moreover, further large case-control studies with follow-up periods would be required to clearly assess the impact of MetS on the clinical outcomes of DLE. PMID:28127570

  10. MAOA, DBH and SLC6A4 variants in CHARGE: A case control study of autism spectrum disorders

    PubMed Central

    Tassone, Flora; Qi, Lihong; Zhang, Wenting; Hansen, Robin L; Pessah, Isaac N; Hertz-Picciotto, Irva

    2011-01-01

    Background Genetic factors are established to contribute to the development of autism. We examined three loci, serotonin transporter (SLC6A4), dopamine hydroxylase (DBH) and the variable number of tandem repeat promoter of the monoamine oxidase A (MAOA) for association with autism in participants from the CHARGE (CHildhood Autism Risks from Genetics and the Environment) Study, the first large-scale population-based case-control investigation of both environmental and genetic contributions to autism risk. Methods Among male children enrolled in the CHARGE study we tested associations between each of the three polymorphisms and autism (AU) (n=119), or a combined group of autism and other autism spectrum disorders (AU+ASD, which includes an additional n=53) as compared with typically developing controls (TD, n=137). Results The case-control association analysis showed neither SLC6A4 nor DBH to be statistically significantly associated with AU or ASD. However, the male children carrying 4 tandem repeats in the promoter region of the MAOA gene showed a 2-fold higher risk of AU (or AU+ASD) than those carrying allele 3, adjusted for confounders (OR = 2.02, 95% CI = 1.12, 3.65, p = 0.02 for AU vs. TD, and OR = 2.05, 95% CI = 1.19, 3.53, p = 0.01 for ASD vs. TD). In addition, mothers homozygous for the 4 tandem repeat allele showed at least a 3-fold higher risk of AU (or AU+ASD) than mothers homozygous for allele 3 (OR = 3.07, 95% CI = 1.19, 7.91, p = 0.02 for AU vs. TD, and OR = 3.26, 95% CI = 1.35, 7.89, p = 0.009 for AU+ASD vs. TD). Conclusions These results suggest a potential role of the functional MAOA promoter alleles in the male child, the mother, or both in autism spectrum disorders. PMID:21538940

  11. Single nucleotide polymorphisms in toll-like receptor genes and case-control association studies with bovine tuberculosis

    PubMed Central

    Bhaladhare, Ashish; Sharma, Deepak; Kumar, Amit; Sonwane, Arvind; Chauhan, Anuj; Singh, Ranvir; Kumar, Pushpendra; Yadav, Ramji; Baqir, Mohd; Bhushan, Bharat; Prakash, Om

    2016-01-01

    Aim: Toll-like receptor 2 (TLR2) and TLR4 genes play critical roles in host recognition of Mycobacterium bovis infection and initiation of innate and adaptive immune response. The present study was aimed at exploring the association of seven single nucleotide polymorphisms (SNPs) in TLR2 and TLR4 genes with susceptibility/resistance against bovine tuberculosis (bTB) infection in cattle. Materials and Methods: A case-control resource population of 35 positive and 45 negative animals was developed after screening with single intradermal tuberculin test for bTB. Resource population was screened for SNPs in TLR2 and TLR4 genes using polymerase chain reaction-restriction fragment length polymorphism. The PROC LOGISTIC procedure of SAS 9.3 was used to find an association of allelic and genotypic frequencies with bTB. Results: In TLR2 gene, two of SNPs under study (rs55617172 and rs68268253) revealed polymorphism while in the case of TLR4 gene all four SNPs under investigation (rs8193041, rs207836014, rs8193060, and rs8193069) were found to be polymorphic in case-control population. SNP locus rs55617172 in TLR2 gene was found significantly (p<0.01) associated with susceptibility/resistance to TB in cattle. Conclusion: These findings indicate the presence of SNPs in TLR2 and TLR4 genes in our resource population. Upon validation in independent, large resource population and following biological characterization, SNP rs55617172 can be incorporated in marker panel for selection of animals with greater resistance to bTB. PMID:27284220

  12. Active and involuntary tobacco smoking and upper-aerodigestive-tract cancer risks in a multicenter case-control study

    PubMed Central

    Lee, Yuan-Chin Amy; Marron, Manuela; Benhamou, Simone; Bouchardy, Christine; Ahrens, Wolfgang; Pohlabeln, Hermann; Lagiou, Pagona; Trichopoulos, Dimitrios; Agudo, Antonio; Castellsague, Xavier; Bencko, Vladimir; Holcatova, Ivana; Kjaerheim, Kristina; Merletti, Franco; Richiardi, Lorenzo; Macfarlane, Gary J.; Macfarlane, Tatiana V.; Talamini, Renato; Barzan, Luigi; Canova, Cristina; Simonato, Lorenzo; Conway, David I.; McKinney, Patricia A.; Lowry, Raymond J.; Sneddon, Linda; Znaor, Ariana; Healy, Claire M.; McCartan, Bernard E.; Brennan, Paul; Hashibe, Mia

    2012-01-01

    Introduction Several important issues for the established association between tobacco smoking and upper-aerodigestive tract (UADT) cancer risks include the associations with smoking by cancer subsite, by type of tobacco, and among never alcohol drinkers, and the associations with involuntary smoking among nonsmokers. Our aim was to examine these specific issues in a large scale case-control study in Europe. Methods Analysis was performed on 2,103 UADT squamous cell carcinoma cases and 2,221 controls in the Alcohol-Related Cancers and Genetic Susceptibility in Europe (ARCAGE) project, a multicenter case-control study in 10 European countries. Unconditional logistic regression was performed to obtain odds ratios (OR) and 95% confidence intervals (CI). Results Compared to never tobacco smoking, current smoking was associated with UADT cancer risks (OR=6.72, 95% CI 5.45–8.30 for overall; 5.83, 4.50–7.54 for oral cavity and oropharynx; 12.19, 8.29–17.92 for hypopharynx and larynx; 4.17, 2.45–7.10 for esophagus). Among never drinkers, dose-response relationships with tobacco smoking packyears were observed for hypopharyngeal and laryngeal cancers (ptrend = 0.01), but not for oral cavity and oropharyngeal cancers (ptrend = 0.282). Among never smokers, ever exposure to involuntary smoking was associated with an increased risk of UADT cancers (OR=1.60, 95% CI 1.04–2.46). Conclusion Our results corroborate that tobacco smoking may play a stronger role in the development of hypopharyngeal and laryngeal cancers than that of oral cavity and oropharyngeal cancers among never drinkers and that involuntary smoking is an important risk factor for UADT cancers. Public health interventions to reduce involuntary smoking exposure could help reduce UADT cancer incidence. PMID:19959682

  13. Association between signs and symptoms of temporomandibular disorders and pregnancy (case control study).

    PubMed

    Mayoral, Verónica A; Espinosa, Irene A; Montiel, Alvaro J

    2013-01-01

    Temporomandibular disorders (TMD) are a combination of multifactoral etiological muscular-skeletal symptoms. Prevalence is greater in women, where sexual hormones are important in pathogenesis, and its behavior at different stages of the reproductive life of women has never been fully documented. The general objective was to determine the association between signs and symptoms of temporomandibular disorders and pregnancy. A case-control study was conducted on 66 pregnant patients who met with a medical specialist and 66 non-pregnant women paired by age, who visited the General Regional Hospital 36 of Mexico's Social Security Institute (IMSS). These patients were examined for the Temporomandibular (TMD) research project to establish the prevalence of TMD in both groups. Descriptive variables were calculated through him SPSS 17 program and the association between groups with Xi Square and Ratio Possibilities (OR), The average age was 28.23 +/- 5.9 years in both groups, with median gestation 32.97 weeks. Most of the participants had a domestic partner. The prevalence of TDM in the non-pregnant group was 45.5% and only 15.2% in the pregnant group (chi2 = 14.34, p < .000). We calculated the ratio of possibilities (RP) pregnant/non-pregnant with a value of 41 with confidence intervals from 23 to 72. In conclusion, pregnancy protects women from TDM signs and symptoms. Pregnant women have a considerably lower prevalence of these disorders.

  14. Prevalence of Small Intestinal Bacterial Overgrowth among Chronic Pancreatitis Patients: A Case-Control Study

    PubMed Central

    Bouchard, Simon; Sidani, Sacha

    2016-01-01

    Background. Patients with chronic pancreatitis (CP) exhibit numerous risk factors for the development of small intestinal bacterial overgrowth (SIBO). Objective. To determine the prevalence of SIBO in patients with CP. Methods. Prospective, single-centre case-control study conducted between January and September 2013. Inclusion criteria were age 18 to 75 years and clinical and radiological diagnosis of CP. Exclusion criteria included history of gastric, pancreatic, or intestinal surgery or significant clinical gastroparesis. SIBO was detected using a standard lactulose breath test (LBT). A healthy control group also underwent LBT. Results. Thirty-one patients and 40 controls were included. The patient group was significantly older (53.8 versus 38.7 years; P < 0.01). The proportion of positive LBTs was significantly higher in CP patients (38.7 versus 2.5%: P < 0.01). A trend toward a higher proportion of positive LBTs in women compared with men was observed (66.6 versus 27.3%; P = 0.056). The subgroups with positive and negative LBTs were comparable in demographic and clinical characteristics, use of opiates, pancreatic enzymes replacement therapy (PERT), and severity of symptoms. Conclusion. The prevalence of SIBO detected using LBT was high among patients with CP. There was no association between clinical features and the risk for SIBO. PMID:27446865

  15. The Utah Leukemia Case-Control Study: dosimetry methodology and results.

    PubMed

    Simon, S L; Till, J E; Lloyd, R D; Kerber, R L; Thomas, D C; Preston-Martin, S; Lyon, J L; Stevens, W

    1995-04-01

    This paper discusses the dosimetry methodology used to estimate bone marrow dose and the results of dosimetry calculations for 6,507 subjects in an epidemiologic case-control study of leukemia among Utah residents. The estimated doses were used to determine if a higher incidence of leukemia among residents of Utah could have been attributed to exposure to radioactive fallout from above-ground nuclear weapons tests conducted at the Nevada Test Site. The objective of the dosimetry methodology was to estimate absorbed dose to active marrow specific to each case and each control subject. Data on the residence of each subject were available from records of the Church of Jesus Christ of Latter-day Saints. Deposition of fallout was determined from databases developed using historical measurements and exposure for each subject from each test was estimated using those data. Exposure was converted to dose by applying an age-dependent dose conversion factor and a factor for shielding. The median dose for all case and control subjects was 3.2 mGy. The maximum estimated mean dose for any case or control was 29 +/- 5.6 mGy (a resident of Washington County, UT). Uncertainties were estimated for each estimated dose. The results of the dosimetry calculations were applied in an epidemiological analysis.

  16. Antidepressants and Valvular Heart Disease: A Nested Case-Control Study in Taiwan.

    PubMed

    Lin, Chia-Hui; Hsiao, Fei-Yuan; Liu, Yen-Bin; Gau, Susan Shur-Fen; Wang, Chi-Chuan; Shen, Li-Jiuan

    2016-04-01

    Empirical evidence regarding the association between antidepressants and valvular heart disease (VHD) is scarce.Using Taiwan's National Health Insurance Research database, this nested case-control study assessed the association between antidepressants and VHD in a Chinese population.Among a cohort of patients who used at least 3 prescription antidepressants, 874 cases with VHD and 3496 matched controls (1:4 ratio) were identified. Conditional logistic regression models were used to examine the timing, duration, dose and type of antidepressants use, and the risk of VHD.Current use of antidepressants was associated with a 1.4-fold increase in the risk of VHD (adjusted odds ratio [aOR] 1.44; 95% confidence interval [CI] 1.17-1.77). Among current users, a dose-response association was observed in terms of the cumulative duration and the cumulative antidepressant dose. Significantly higher risks of VHD were observed among the current users of tricyclic antidepressants (aOR 1.40 [1.05-1.87]).We found that the use of antidepressants was associated with a greater risk of VHD and that the risks varied according to different antidepressants.

  17. Cryptosporidiosis in Wisconsin: a case-control study of post-outbreak transmission.

    PubMed

    Osewe, P; Addiss, D G; Blair, K A; Hightower, A; Kamb, M L; Davis, J P

    1996-10-01

    During March-April 1993, an estimated 403000 residents of the 5-county greater Milwaukee, Wisconsin area developed cryptosporidiosis after drinking contaminated municipal water. Although the number of cases dropped precipitously after the implicated water plant closed on 9 April, cases continued to occur. To investigate risk factors for post-outbreak cryptosporidiosis, 33 Milwaukee-area residents who had laboratory-confirmed Cryptosporidium infection with onset of diarrhoea between 1 May and 27 June 1993 were interviewed by telephone. Of these, 28 (85%) had onset of diarrhoea during May, 12 (36%) had watery diarrhoea during the outbreak, and 5(15%) were HIV-infected. In a neighbourhood-matched case-control study, immunosuppression (matched odds ratio (MOR) not calculable, 95% confidence interval (CI) 3.0, infinity) and having a child less than 5 years old in the household (MOR = 17.0, CI 2.0, 395.0) were independently associated with infection. When persons who had diarrhoea during the outbreak were excluded, immunosuppression remained significantly associated with illness (MOR not calculable, CI 1.6, infinity). Cryptosporidium transmission continued after this massive waterborne outbreak but decreased rapidly within 2 months.

  18. Efficacy of endoscopic screening in an isolated island: a case-control study.

    PubMed

    Matsumoto, Satohiro; Yoshida, Yukio

    2014-01-01

    Although endoscopic screening has become more common in recent years, its efficacy in reducing the mortality from gastric cancer has not yet been demonstrated. We carried out a case-control study to evaluate the efficacy of endoscopic screening in Kamigoto town, Kamigoto Island. The case group consisted of 13 patients who died of gastric cancer between 2000 and 2008, and ten controls per patient, ie. a total of 130 controls, were extracted as the control group. To clarify the relationship between participation in endoscopic screening and gastric cancer mortality, the odds ratio of death from gastric cancer in participants vs. nonparticipants of screening was calculated. The odds ratio of death from gastric cancer in participants of endoscopic screening vs. nonparticipants was 0.206 (95 % CI, 0.044-0.965; p = 0.0449). Participation in endoscopic screening within the previous 5 years decreased the risk of death from gastric cancer by 79 %. Implementation of endoscopic screening was associated with a significant reduction in mortality from gastric cancer in the small island town.

  19. Varenicline and Risk of Self-Harm: A Nested Case-Control Study

    PubMed Central

    Martins, Diana; Yao, Zhan; Mamdani, Muhammad M.; Juurlink, David N.; Gomes, Tara; Antoniou, Tony

    2016-01-01

    Background Smoking remains a serious public health concern. Pharmacotherapy for smoking cessation, including bupropion and varenicline, are proven means to increase quit rates. Post-marketing reports describing suicidal behaviours have raised concerns about the safety of varenicline. However, whether varenicline imparts a higher risk of suicide relative to bupropion remains uncertain. Methods A population-based nested case-control study in Ontario, Canada, from April 1, 2011 to March 31, 2015 was conducted. Subjects were residents of Ontario aged 18 years and older with publicly funded drug coverage receiving either bupropion or varenicline for smoking cessation. We defined cases were those with a hospitalization or emergency department visit for suicide or non-fatal self-harm within 90 days of treatment. For each case, we identified up to fifty controls from the same cohort matched on age, sex, history of self-harm, use of selected psychotropic medications, alcohol abuse and prior admission to a mental health unit. Adjusted odds ratio were used to compare the risk of suicide/self-harm of varenicline to bupropion. Results We identified 331 cases and 5,346 matched-controls. Following adjustment for potential confounders, we found that varenicline was not associated with an increased risk of suicide/self-harm relative to bupropion (adjusted odds ratio 1.15; 95% confidence interval 0.71 to 1.87). Interpretation Treatment with varenicline does not appear to significantly increase the risk of suicide or self-harm relative to bupropion. PMID:27662654

  20. Environmental risk factors in pediatric psoriasis: a multicenter case-control study.

    PubMed

    Ozden, Müge G; Tekin, Nilgün S; Gürer, Mehmet A; Akdemir, Devrim; Doğramacı, Ciğdem; Utaş, Serap; Akman, Ayşe; Evans, Sibel E; Bahadır, Sevgi; Oztürkcan, Serap; Ikizoğlu, Güliz; Sendur, Neslihan; Köse, Osman; Bek, Yüksel; Yaylı, Savaş; Cantürk, Tayyar; Turanl, Ahmet Y

    2011-01-01

    To analyze the effect of possible risk factors, including breastfeeding, on the development of childhood-onset psoriasis, a multicenter case-control study with prospective collection of data was performed. Using a standard questionnaire, personal and specific variables including family history of psoriasis, maternal and environmental tobacco smoke exposure, body mass index (BMI), exclusive and partial breastfeeding for at least 3 and 12 months, cow's milk intake before 1 year, birth delivery method, and stressful life events were collected during 2009 from 537 patients with psoriasis and 511 controls younger than 18. Overall, patients more frequently reported exposure to environmental tobacco smoke at home and stressful life events in the year preceding the diagnosis than controls. The odds ratios (OR) for smoking and stressful life events were 2.90 (95% confidence interval [CI]=2.27-3.78) and 2.94 (95% CI=2.28-3.79), respectively. In addition, children with psoriasis were more likely to have a higher BMI (>26) than controls (OR=2.52; 95% CI=1.42-4.49). High BMI, environmental tobacco smoke exposure at home, and stressful life events may influence the development of pediatric psoriasis.

  1. Domestic incense burning and nasopharyngeal carcinoma: a case-control study in Hong Kong Chinese.

    PubMed

    Xie, Shao-Hua; Yu, Ignatius Tak-sun; Tse, Lap Ah; Au, Joseph Siu Kie; Wang, Feng; Lau, June Sze Man; Zhang, Bo

    2014-12-01

    Incense burning is a powerful producer of carcinogens and has been considered as a risk factor for nasopharyngeal carcinoma (NPC). We conducted a case-control study and case-only analyses to investigate the effect of incense burning and its interaction with genetic background on NPC risk among Hong Kong Chinese. Between June 2010 and December 2012, we recruited 352 incident cases of NPC and 410 controls. We collected information on lifelong practice of domestic incense burning via interviews and genotyped 80 single nucleotide polymorphisms (SNPs) in DNA repair genes. We observed an increased NPC risk associated with daily burning in women [Adjusted OR = 2.49, 95% confidence interval (CI): 1.33, 4.66] but not in men. The adjusted OR for daily burning with poor ventilation was 2.08 (95% CI: 1.02, 4.24), while that with good ventilation was 1.35 (95% CI: 0.92, 1.98). Interactions between 2 SNPs (rs2074517 and rs4771436) and incense burning were significantly associated with NPC risk and tended to have a SNP exposure-response effect. Evidence for gene-environment interactions supported the knowledge that NPC is a multi-factorial disease resulting from the joint effects of environmental exposures and inherited susceptibility.

  2. Urine metabolomics in neonates with late-onset sepsis in a case-control study

    PubMed Central

    Sarafidis, Kosmas; Chatziioannou, Anastasia Chrysovalantou; Thomaidou, Agathi; Gika, Helen; Mikros, Emmanouel; Benaki, Dimitra; Diamanti, Elisavet; Agakidis, Charalampos; Raikos, Nikolaos; Drossou, Vasiliki; Theodoridis, Georgios

    2017-01-01

    Although late-onset sepsis (LOS) is a major cause of neonatal morbidity and mortality, biomarkers evaluated in LOS lack high diagnostic accuracy. In this prospective, case-control, pilot study, we aimed to determine the metabolic profile of neonates with LOS. Urine samples were collected at the day of initial LOS evaluation, the 3rd and 10th day, thereafter, from 16 septic neonates (9 confirmed and 7 possible LOS cases) and 16 non-septic ones (controls) at respective time points. Urine metabolic profiles were assessed using non-targeted nuclear magnetic resonance spectroscopy and targeted liquid chromatography-tandem mass spectrometry analysis. Multivariate statistical models with data from either analytical approach showed clear separation between the metabolic profiles of septic neonates (both possible and confirmed) and the controls. Metabolic changes appeared to be related to disease progression. Overall, neonates with confirmed or possible LOS exhibited comparable metabolic profiles indicating similar metabolic alternations upon the onset of clinical manifestations. This methodology therefore enabled the discrimination of neonates with LOS from non-septic individuals, providing potential for further research toward the discovery of LOS-related biomarkers. PMID:28374757

  3. A case-control study of mesothelioma and employment in the Hawaii sugarcane industry.

    PubMed

    Sinks, T; Goodman, M T; Kolonel, L N; Anderson, B

    1994-07-01

    We conducted a case-control study of 93 mesothelioma cases and 281 cancer controls to determine whether sugarcane workers exposed to biogenic silica fibers were at increased risk of mesothelioma. We found no important excess risk of mesothelioma in sugarcane workers [odds ratio (OR) = 1.3; 95% confidence interval (CI) = 0.4-3.8] when we excluded all control subjects with cancer of sites suspected of being associated with asbestos exposure. We could not identify any sugarcane workers who developed mesothelioma and worked in jobs where high exposure levels of biogenic silica fibers have been measured. We did confirm that mesothelioma risk in Hawaii is associated with probable occupational asbestos exposure. Work at the Pearl Harbor Naval Shipyard was associated with a 10-fold increase in mesothelioma when we excluded controls with cancer of sites related to asbestos exposure (OR = 10.1; 95% CI = 2.6-56.6). Work in the medical industry was also associated with an unexpected increased risk for mesothelioma (OR = 4.2; 95% CI = 1.2-15.5).

  4. Risk factors for sporadic Vibrio parahaemolyticus gastroenteritis in east China: a matched case-control study.

    PubMed

    Yan, W X; Dai, Y; Zhou, Y J; Liu, H; Duan, S G; Han, H H; Chen, Y

    2015-04-01

    SUMMARY To determine risk factors for sporadic Vibrio parahaemolyticus gastroenteritis, we conducted a population-based case-control study in sentinel hospital surveillance areas of Shanghai and Jiangsu province, China. Seventy-one patients with diarrhoea and confirmed V. parahaemolyticus infections were enrolled, and they were matched with 142 controls for gender, age and residential area. From the multivariable analysis, V. parahaemolyticus infections were associated with antibiotics taken during the 4 weeks prior to illness [odds ratio (OR) 7·6, 95% confidence interval (CI) 1·1–54·4)], frequent eating out (OR 3·3, 95% CI 1·0–10·4), and shellfish consumption (OR 3·4, 95% CI 1·0–11·1), with population-attributable fractions of 0·09, 0·24, and 0·14, respectively. Protective factors included keeping the aquatic products refrigerated (OR 0·4, 95% CI 0·2–1·0) and pork consumption (OR 0·2, 95% CI 0·1–0·9) [corrected] .

  5. Mode of Delivery in Drug-Dependent Pregnant Women: A Case Control Study

    PubMed Central

    Neves, Fabiane; Santos Silva, Isabel; Almeida, Maria do Céu; Monteiro, Pitorra

    2017-01-01

    Objective. To determine the contribution of drug use during pregnancy to the route of delivery. Methods. A case-control study was conducted at a hospital in Coimbra, Portugal, between 2001 and 2014. Drug-dependent pregnant women (n = 236) were compared with a control group of low risk women (n = 228) in terms of maternal characteristics, obstetric history, pregnancy complications, and labor details. Factors that influenced the mode of delivery were determined. Statistical analysis was performed with SPSS v. 23.0 (IBM Corp.). p values < 0.05 were considered statistically significant. Results. Drug-dependent women presented a lower rate of cesarean delivery (18.2 versus 28.9%, p = 0.006). After adjusting for the factors that were significantly related to the mode of delivery, drug dependency influenced the rate of cesarean section (β = 0.567; 95% CI = 0.328–0.980). Within the drug-dependent group, the mode of delivery was significantly related to previous cesarean or vaginal delivery (p = 0.008 and p < 0.001, resp.) and fetal presentation (p < 0.001), but not with the type of drug, route of administration, or substitution maintenance therapy. Conclusions. The drug-dependent group presented a significantly higher rate of vaginal delivery. However, this was not associated with the behavioral factors analyzed. We hypothesize that other social and psychological factors might explain this difference. PMID:28331637

  6. Outcomes of hematopoietic SCT recipients with rhinovirus infection: a matched, case-control study.

    PubMed

    Abandeh, F I; Lustberg, M; Devine, S; Elder, P; Andritsos, L; Martin, S I

    2013-11-01

    The impact of rhinovirus in hematopoietic SCT (HSCT) recipients is not well defined. A retrospective, matched, case-control study of HSCT recipients with rhinovirus was conducted between 2009 and 2011. Controls were matched for timing relative to transplant, malignancy, and stem cell source. There were 47 cases and 94 controls. The cases and controls did not differ with respect to age, gender, ethnicity, donor source, malignancy, conditioning regimen, immunosuppression, antimicrobial prophylaxis or significant comorbidities. There were no differences in need for intensive care unit care, 100 day mortality, hospice discharge, relapse of disease, GVHD or development of disease or infection due to CMV or EBV. Other infectious complications after rhinovirus diagnosis were also equal. However, there was an increased number of recurrent hospitalizations from any cause among the cases (46.8% vs 24.5%, P=0.007). Recurrent hospitalizations due to any infection were also more common in cases (34% vs 14.9%, P=0.015). For patients who were diagnosed with rhinovirus pre-transplant (n=13), there was no difference in outcome compared with matched controls. HSCT recipients with rhinovirus have an increased risk of hospital readmission. However, there was no difference in outcome compared with matched controls. Transplantation in patients with active rhinovirus infection appears to be safe.

  7. Case-control study of bladder cancer and water disinfection methods in Colorado.

    PubMed

    McGeehin, M A; Reif, J S; Becher, J C; Mangione, E J

    1993-10-01

    A population-based case-control study of bladder cancer and drinking water disinfection methods was conducted during 1990-1991 in Colorado. Surface water in Colorado has historically been disinfected with chlorine (chlorination) or with a combination of chlorine and ammonia (chloramination). A total of 327 histologically verified bladder cancer cases were frequency matched by age and sex to 261 other-cancer controls. Subjects were interviewed by telephone about residential and water source histories. This information was linked to data from water utility and Colorado Department of Health records to create a drinking water exposure profile. After adjustment for cigarette smoking, tap water and coffee consumption, and medical history factors by logistic regression, years of exposure to chlorinated surface water were significantly associated with risk for bladder cancer (p = 0.0007). The odds ratio for bladder cancer increased for longer durations of exposure to a level of 1.8 (95% confidence interval 1.1-2.9) for more than 30 years of exposure to chlorinated surface water compared with no exposure. The increased bladder cancer risk was similar for males and females and for nonsmokers and smokers. Levels of total trihalomethanes, nitrates, and residual chlorine were not associated with bladder cancer risk after controlling for years of exposure to chlorinated water.

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

    PubMed Central

    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 [Pg], Aggregatibacer actinomycetemcomitans [Aa], Fusobacterium nucleatum [Fn], Prevotella intermedia [Pi], Tannerella forsythia [Tf], and Treponema denticola [Td]) and three herpesviruses (Epstein-Barr virus [EBV], human cytomegalovirus [HCMV], and herpes simplex virus [HSV]) were detected. Socio-demographic data and oral health related behaviors, and salivary estradiol and progesterone levels were also collected. The results showed no significant differences in socio-demographic background, oral health related behaviors, and salivary estradiol and progesterone levels between the two groups (all P > 0.05). The detection rates of included periodontopathic microorganisms were not significantly different between the two groups (all P > 0.05), but the coinfection rate of EBV and Pg was significantly higher in the case group than in the control group (P = 0.028). EBV and Pg coinfection may promote the development of chronic periodontitis among pregnant women. PMID:27301874

  9. Case-control study of urinary bladder cancer in metropolitan Nagoya.

    PubMed

    Ohno, Y; Aoki, K; Obata, K; Morrison, A S

    1985-12-01

    We conducted a population-based case-control study of patients with bladder cancer and of controls drawn randomly from the general population of Metropolitan Nagoya and interviewed both groups. The incidence rates of bladder cancer were 2.42 and 7.05/100,000 for females and males, respectively. The analysis, based on 293 patients and 589 controls who were frequency matched for age, sex, and residence, provided the following major findings. Age-adjusted relative risks of 1.89 (1.15-3.10) and 3.53 (1.71-7.27) were found in male and female cigarette smokers, respectively. Significant relative risk was also found in males who drank cocoa. Elevated risk with a dose-response relationship was observed among women who used hair dye and who smoke, but this risk was insignificant, with the disappearance of a dose-response relationship, when it was adjusted for smoking. Age- and smoking-adjusted relative risk of coffee drinking was insignificant with no dose-response relationship. Relative risk of artificial sweetener use was below 1 with adjustment for age and smoking. Intake of alcoholic beverages and cola was insignificantly associated. Reduced risk of significance was suggested for the intake of black tea and matcha (powdered green tea) in females and of fruit juice in males.

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

    PubMed

    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 <0.01), smoking (60.7% versus 21.4%; p <0.01), the absence of previously known valve disease (82.1% versus 60.7%; p 0.047), heart failure (64.3% versus 23.2%; p <0.01) and shock (53.6% versus 23.2%; p <0.01) were more common in pneumococcal than in non-pneumococcal 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.

  11. Level of neurotoxic metals in amyotrophic lateral sclerosis: A population-based case-control study.

    PubMed

    Bocca, Beatrice; Forte, Giovanni; Oggiano, Riccardo; Clemente, Simonetta; Asara, Yolande; Peruzzu, Angela; Farace, Cristiano; Pala, Salvatore; Fois, Alessandro Giuseppe; Pirina, Pietro; Madeddu, Roberto

    2015-12-15

    The association between exposure to toxic metals and amyotrophic lateral sclerosis (ALS) was explored in a population-based case-control study in the Sardinia island (Italy), a region characterized by elevated rates of ALS cases. In 34 patients with ALS (mean age, 62 ± 10 years) and 30 controls (mean age, 65 ± 11 years), Al, Cd, Hg, Mn and Pb were determined in blood, hair and urine by sector field inductively coupled mass spectrometry. Results indicated that, in blood, concentrations of Al (p=0.045) and Pb were higher (p=0.026) in ALS patients than in control subjects. In hair, a depletion of Al (p=0.006) and Mn (p=0.032) concentrations in ALS subjects respect to controls was found. In urine, no significant differences between cases and controls were observed. Thus, some metals seemed to be associated with ALS degeneration, but a definitive conclusion is still far considering the multiple risk factors (genetic mutations, environmental toxicants and stressors) involved in the disease. Finally, the interpretation that deregulated metal concentrations can be a consequence of the degenerative process, rather than a cause, is also valid.

  12. Decompression sickness from saturation diving: a case control study of some diving exposure characteristics.

    PubMed

    Jacobsen, G; Jacobsen, J E; Peterson, R E; McLellan, J H; Brooke, S T; Nome, T; Brubakk, A O

    1997-06-01

    A comprehensive computerized database of diving activity for a Norwegian offshore diving contractor [Stolt-Nielsen Seaway (SNS)] covering the years 1983-1990 has been established. The database contains detailed dive information about 12,087 surface-oriented and 2,622 saturation dives. During this period a majority of the divers were permanently employed. Preliminary analysis had suggested that decompression sickness (DCS) might be the result of exposure to factors causing pathophysiologic effects which accumulate over the course of a single dive or a series of dives. This concept evolved into the HADES (Highest Accumulated Decompression Score) theory which assumes that DCS is predictable once the underlying exposure factors are understood. The incidence of DCS among the SNS divers from saturation diving in the North Sea was studied by use of a "nested" case-control design. Twenty-one case dives (i.e., dives where DCS occurred) were compared with 41 randomly selected control dives. For these dives, several saturation dive characteristics were established. The relative pressure change between maximum and minimum storage depths was significantly greater among the cases. For each 1% increase in the relative pressure change there was a 5% increase in the probability of a saturation dive resulting in DCS. Significantly more cases than controls performed a saturation dive with more than one storage depth, and the data suggested that there were more and greater ascending and descending changes in storage depth conditions among the affected divers.

  13. Epidemiological case-control study on the etiology of bladder cancer in Turkey.

    PubMed

    Akdaş, A; Kirkali, Z; Bilir, N

    1990-01-01

    A case-control study of 194 patients with bladder cancer and the same number of age- and sex-matched hospital controls were interviewed to estimate the role of various factors on the etiology of bladder cancer in Turkey. There was a significant difference between the case and control groups on cigarette smoking (p less than 0.001), alcohol intake (p less than 0.001), Turkish coffee consumption (p = 0.01), and artificial sweeteners (p less than 0.05). The risks for alcohol and tobacco users increased in correlation with the duration of exposure. The risk of bladder cancer increased directly with the quantity and frequency of alcohol intake. Alcohol and coffee drinking was found to be a promoting factor when adjusted to smoking habits (p less than 0.05). No statistical comparisons could be made to clarify the risks attributed by occupation and place of residence due to small figures in each group. However, in farmers, there was a significant difference between the cases and controls on the use of artificial fertilizers and insecticides (p less than 0.01). People who were exposed to unspecified chemical substances were more prone to develop bladder cancer (p less than 0.001). We conclude that both personal habits and exogenous carcinogens play a role in the etiology of bladder tumors.

  14. A case-control study of lactation and cancer of the breast.

    PubMed Central

    Katsouyanni, K.; Lipworth, L.; Trichopoulou, A.; Samoli, E.; Stuver, S.; Trichopoulos, D.

    1996-01-01

    We have examined the relation of lactation, by total duration, with breast cancer risk among pre- and post-menopausal women. In a hospital-based case-control study conducted in Athens (1989-91), involving 820 patients with confirmed breast cancer and 795 orthopaedic patient controls and 753 hospital visitor controls, logistic regression was used to analyse the data controlling for demographic, nutritional and reproductive factors, including parity and age at any birth. Among post-menopausal women, there was no association between breastfeeding and breast cancer risk, but among premenopausal women those who has breastfed for > or = 24 months had an odds ratio of 0.50 (95% confidence interval 0.23-1.41). A reduction of the odds ration was also evident among premenopausal women who had breastfed between 12 and 23 months (odds ratio 0.70; 95% confidence interval 0.34-1.60). In conjunction with several other recent reports these results support the hypothesis that breastfeeding of prolonged duration may reduce the risk of breast cancer among premenopausal women but not among post-menopausal women. The biology underlying this different effect remains unknown, and the practical implication of the finding is a marginal importance. PMID:8611387

  15. The Utah leukemia case-control study: Dosimetry methodology and results

    SciTech Connect

    Simon, S.L.; Kerber, R.L.; Stevens, W.

    1995-04-01

    This paper discusses the dosimetry methodology used to estimate bone marrow dose and the results of dosimetry calculations for 6,507 subjects in an epidemiologic case. control study of leukemia among Utah residents. The estimated doses were used to determine if a higher incidence of leukemia among residents of Utah could have been attributed to exposure to radioactive fallout from above-ground nuclear weapons tests conducted at the Nevada Test Site. The objective of the dosimetry methodology was to estimate absorbed dose to active marrow specific to each case and each control subject. Data on the residence of each subject were available from records of the Church of Jesus Christ of Latter-day Saints. Deposition of fallout was determined from databases developed using historical measurements and exposure for each subject from each test was estimated using those data. Exposure was converted to dose by applying an age-dependent dose conversion factor and a factor for shielding. The median dose for all case and control subjects was 3.2 mGy. The maximum estimated mean dose for any case or control was 29 {plus_minus} 5.6 mGy (a resident of Washington County, UT). Uncertainties were estimated for each estimated dose. The results of the dosimetry calculations were applied in an epidemiological analysis.

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

    PubMed

    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.

  17. Meat, milk and risk of lymphoid malignancies: a case-control study in Uruguay.

    PubMed

    De Stefani, Eduardo; Ronco, Alvaro L; Deneo-Pellegrini, Hugo; Boffetta, Paolo; Correa, Pelayo; Barrios, Enrique; Acosta, Gisele; Mendilaharsu, María

    2013-01-01

    In the time period 1996-2004, 697 cases with lymphoid neoplasms and 3606 controls with nonneoplastic conditions were included in a case-control study conducted in the Cancer Institute of Uruguay. They were administered a routine questionnaire that included 8 sections and a food frequency questionnaire focused on intakes of total meat, red meat, salted meat, barbecued meat, processed meat, milk, total vegetables and total fruits, and alcoholic beverages. Lymphoid cancers were analyzed by multiple polytomous regression. Red meat, salted meat, and milk were positively associated with risk of lymphoid cancers [odds ratios (OR) for the highest tertile vs. the lowest one of red meat = 1.68, 95% confidence interval (CI) 1.37-2.08, OR for whole milk = 2.92, 95% CI 2.63-3.63). On the other hand, plant foods, particularly total fruits, and alcoholic beverages (mainly red wine) were protective. We could conclude that these foods could play a significant role in the etiology of lymphoid malignancies.

  18. Association between chronic periodontitis and rheumatoid arthritis: a hospital-based case-control study.

    PubMed

    Joseph, Rosamma; Rajappan, Sreeraj; Nath, Sameera G; Paul, Binoy J

    2013-01-01

    Rheumatoid arthritis (RA) and chronic periodontitis are the most common chronic inflammatory diseases with remarkable pathological and clinical similarities. A lot of similarities exist between RA and periodontitis at cellular and molecular levels. The relationship between these two chronic inflammatory diseases is still unclear. This case-control study was undertaken to determine the possible association between chronic inflammatory diseases like RA and periodontitis. The case group consisted of 100 patients attending the Rheumatology clinic who have rheumatoid arthritis (RA group). Age- and gender-matched 112 patients without RA attending the Outpatient wing of Department of General Medicine formed the control group (NRA group). The number of missing teeth, gingival index (GI), oral hygiene index-simplified (OHI-S), probing pocket depth (PPD) and clinical attachment levels (CAL) were evaluated in both the groups. Rheumatoid disease activity was assessed by DAS-28 score system. Systemic markers of inflammation like erythrocytic sedimentation rate (ESR) and serum levels of C-reactive protein (CRP) were assessed. There was a statistically significant difference in GI, OHI-S, PPD, CAL, ESR and CRP levels between cases (RA group) and controls (NRA group) (P < 0.05). Among subjects with RA, there was no association between the rheumatoid disease activity and the severity of periodontal disease. The occurrence and severity of periodontitis was found to be higher in RA subjects as compared to subjects without RA, suggesting a positive relation between these two chronic inflammatory diseases.

  19. Simultaneous estimation of the locations and effects of multiple disease loci in case-control studies.

    PubMed

    Chien, Li-Chu; Chiu, Yen-Feng; Liang, Kung-Yee; Chuang, Lee-Ming

    2015-04-01

    The genetic basis of complex diseases often involves multiple causative loci. Under such a disease etiology, assuming one disease locus in linkage disequilibrium mapping is likely to induce bias and lead to efficiency loss in disease locus estimation. An approach is needed for simultaneously localizing multiple functional loci within the same region. However, due to the increasing number of parameters accompanying disease loci, these estimates can be computationally infeasible. To circumvent this problem, we propose to estimate the main and two-adjacent-locus joint effects and a nuisance parameter at the disease loci separately through a linear approximation. Estimates of the genetic effects are entered into a generalized estimating equation to estimate disease loci, and the procedure is conducted iteratively until convergence. The proposed method provides estimates and confidence intervals (CIs) for the disease loci, the genetic main effects, and the joint effects of two adjacent disease loci, with the CIs for the disease loci providing useful regions for further fine-mapping. We apply the proposed approach to a data example of case-control studies. Results of the simulations and data example suggest that the developed method performs well in terms of bias, variance, and coverage probability under scenarios with up to three disease loci.

  20. Evaluating Bone Health in Egyptian Children with Forearm Fractures: A Case Control Study

    PubMed Central

    Elbatrawy, Salwa; Gobashy, Amr; Moreira, Alvaro

    2016-01-01

    Objective. To determine the likelihood of vitamin D deficiency and low bone mineral density in Egyptian children with forearm fractures. Methods. A case control study of 46 children aged 3 to 10 years with or without forearm fractures. Validated questionnaires were used to assess calcium and vitamin D intake as well as sun exposure. Serum calcium, phosphorus, alkaline phosphatase, and 25-hydroxy-vitamin D were collected. Bone mineral density was evaluated using dual-energy X-ray absorptiometry. Results. Compared to the Control group, calcium and vitamin D intake was lower in the Cases group (p = 0.03). Cases had higher Body Mass Index than Controls, p = 0.01. Children in the Cases group had lower mean serum calcium values 8.3 ± 1.4 compared to 9.3 ± 1.1 in Controls (p = 0.01). Alkaline phosphatase was higher in Cases 265 ± 65.8 than Controls 226 ± 54.6 (p = 0.03). Vitamin D and bone mineral density scores were significantly lower in the Cases group (p < 0.05). Conclusion. Our data shows an increased rate of vitamin D deficiency and decreased bone mineral density in Egyptian children with forearm fractures. PMID:27651803

  1. Risk factors for sporadic Campylobacter infections: results of a case-control study in southeastern Norway.

    PubMed Central

    Kapperud, G; Skjerve, E; Bean, N H; Ostroff, S M; Lassen, J

    1992-01-01

    In 1989 and 1990, a case-control study designed to identify risk factors for sporadic infections with thermotolerant Campylobacter bacteria was conducted in three counties in southeastern Norway. The investigation was confined to infections which were acquired in Norway. A total of 52 bacteriologically confirmed cases and 103 controls matched by age, sex, and geographic region were interviewed. The following risk factors were found to be independently associated with illness in conditional logistic regression analysis: consumption of sausages at a barbecue (odds ratio [OR] = 7.64; P = 0.005), daily contact with a dog (OR = 4.26; P = 0.024), and eating of poultry which was brought into the house raw (frozen or refrigerated) (OR = 3.20; P = 0.024). The risk associated with consumption of sausages at a barbecue could not be attributed to cross-contamination from poultry products. By univariate analysis, consumption of poultry which was brought raw and frozen was associated with illness (OR = 2.42; P = 0.042), even though freezing substantially reduces the number of viable campylobacters. When poultry consumption was examined by country of origin, eating of poultry produced in Denmark or Sweden was strongly associated with illness (OR = 13.66; P = 0.014), whereas consumption of poultry produced in Norway was not (OR = 1.33; P = 0.41). PMID:1452694

  2. Helicobacter pylori infection is not associated with failure to thrive: a case control study

    PubMed Central

    Chiu, Nan-Chang; Lin, Chien-Yu; Chi, Hsin; Yeung, Chun-Yan; Ting, Wei-Hsin; Chan, Wai-Tao; Jiang, Chuen-Bin; Li, Sung-Tse; Lin, Chao-Hsu; Lee, Hung-Chang

    2017-01-01

    Purpose The long-term impact of Helicobacter pylori infection is complex, and concerns about the need for eradication exist. We conducted this case control study to investigate the association between H. pylori infection and failure to thrive (FTT). Patients and methods From January 2009 to December 2011, 53 children with FTT group and matched children with the same sex and age and similar socioeconomic status without FTT (control group) were enrolled. A questionnaire was administered to the parents/guardian, and a 13C-urea breath test was performed to detect H. pylori infection. Results We found that the total prevalence of H. pylori infection was 29.2% and that there was no association between FTT and H. pylori infection (FTT group: 32%; control group: 26.4%; P=0.67). Short stature was more common in the FTT group and abdominal pain in the control group (FTT group: 37.7%; control group: 11.3%; P=0.003). In a comparison between the H. pylori-positive and -negative groups, abdominal pain (87.1% vs 64%; P=0.032) and the frequency of endoscopy (74.2% vs 32%; P<0.001) were significantly more common in the H. pylori-positive group. Conclusion We found that children with H. pylori infection are at an increased risk for abdominal pain and that FTT is not associated with H. pylori infection. The decision for eradication should be evaluated carefully and individualized. PMID:28260914

  3. A case-control study of the impact of improved sanitation on diarrhoea morbidity in Lesotho.

    PubMed Central

    Daniels, D. L.; Cousens, S. N.; Makoae, L. N.; Feachem, R. G.

    1990-01-01

    A health impact evaluation of the Rural Sanitation Pilot Project in Mohale's Hoek district, Lesotho, was conducted from October 1987 to September 1988. A clinic-based case-control design was used to investigate the impact of improved sanitation on diarrhoea morbidity in young children. The results indicate that under-5-year-olds from households with a latrine may experience 24% fewer episodes of diarrhoea than such children from households without a latrine (odds ratio = 0.76; 95% confidence interval, 0.58-1.01). The impact of latrines on diarrhoea was greater in those households that used more water, practised better personal hygiene, and where the mothers had a higher level of education or worked outside the home. In common with studies conducted in Malawi, Philippines, and Sri Lanka, little evidence was found that the relationship between latrine ownership and diarrhoea was confounded by socioeconomic status or environmental variables. For a sample of cases and controls, data on exposure status (presence or absence of a latrine) that were collected by interview at the clinics agreed closely with those obtained by observation during a home visit. PMID:2208559

  4. Mobile phone use, exposure to radiofrequency electromagnetic field, and brain tumour: a case-control study.

    PubMed

    Takebayashi, T; Varsier, N; Kikuchi, Y; Wake, K; Taki, M; Watanabe, S; Akiba, S; Yamaguchi, N

    2008-02-12

    In a case-control study in Japan of brain tumours in relation to mobile phone use, we used a novel approach for estimating the specific absorption rate (SAR) inside the tumour, taking account of spatial relationships between tumour localisation and intracranial radiofrequency distribution. Personal interviews were carried out with 88 patients with glioma, 132 with meningioma, and 102 with pituitary adenoma (322 cases in total), and with 683 individually matched controls. All maximal SAR values were below 0.1 W kg(-1), far lower than the level at which thermal effects may occur, the adjusted odds ratios (ORs) for regular mobile phone users being 1.22 (95% confidence interval (CI): 0.63-2.37) for glioma and 0.70 (0.42-1.16) for meningioma. When the maximal SAR value inside the tumour tissue was accounted for in the exposure indices, the overall OR was again not increased and there was no significant trend towards an increasing OR in relation to SAR-derived exposure indices. A non-significant increase in OR among glioma patients in the heavily exposed group may reflect recall bias.

  5. A case-control study of wood dust exposure, mutagen sensitivity, and lung cancer risk.

    PubMed

    Wu, X; Delclos, G L; Annegers, J F; Bondy, M L; Honn, S E; Henry, B; Hsu, T C; Spitz, M R

    1995-09-01

    The associations between lung cancer risk, mutagen sensitivity (a marker of cancer susceptibility), and a putative lung carcinogen, wood dust, were assessed in a hospital-based case-control study. There were 113 African -American and 67 Mexican-American cases with newly diagnosed, previously untreated lung cancer and 270 controls, frequency-matched on age, ethnicity, and sex. Mutagen sensitivity ( 1 chromatid break/cell after short-term bleomycin treatment) was associated with statistically significant elevated risk for lung cancer [odds ration (OR) = 4.3; 95% confidence intervals (CI) = 2.3-7.9]. Wood dust exposure was also a significant predictor of risk (overall OR = 3.5; CI = 1.4-8.6) after controlling for smoking and mutagen sensitivity. When stratified by ethnicity, wood dust exposure was s significant risk factor for African-Americans (OR = 5.5; CI = 1.6-18.9) but not for Mexican-Americans (OR = 2.0; CI = 0.5-8.1). The ORs were 3.8 and 4.8 for non-small cell lung cancer in Mexican-Americans (CI = 1.2-18.5). Stratified analysis suggested evidence of strong interactions between wood dust exposure and both mutagen sensitivity and smoking in lung cancer risk.

  6. Occupation and five cancers: a case-control study using death certificates.

    PubMed Central

    Magnani, C; Coggon, D; Osmond, C; Acheson, E D

    1987-01-01

    A case-control approach has been used to examine mortality from five cancers--oesophagus, pancreas, cutaneous melanoma, kidney, and brain--among young and middle aged men resident in three English counties. The areas studied were chosen because they include major centres of chemical manufacture. By combining data from 20 years it was possible to look at local industries with greater statistical power than is possible using routine national statistics. Each case was matched with up to four controls of similar age who died in the same year from other causes. The occupations and industries recorded on death certificates were coded to standard classifications and risk estimates derived for each job category. Where positive associations were found the records of the cases concerned were examined in greater detail to see whether the risk was limited to specific combinations of occupation and industry. The most interesting findings to emerge were risks of brain cancer associated with the production of meat and fish products (relative risk (RR) = 9.7, 95% confidence interval (CI) 2.6-36.8) and with mineral oil refining (RR = 2.9, CI 1.2-7.0), and a cluster of four deaths from melanoma among refinery workers (RR = 16.0, CI CI 1.8-143.2). A job-exposure matrix was applied to the data but gave no strong indications of further disease associations. Local analyses of occupational mortality such as this can usefully supplement national statistics. PMID:3689708

  7. Robust bayesian sensitivity analysis for case-control studies with uncertain exposure misclassification probabilities.

    PubMed

    Mak, Timothy Shin Heng; Best, Nicky; Rushton, Lesley

    2015-05-01

    Exposure misclassification in case-control studies leads to bias in odds ratio estimates. There has been considerable interest recently to account for misclassification in estimation so as to adjust for bias as well as more accurately quantify uncertainty. These methods require users to elicit suitable values or prior distributions for the misclassification probabilities. In the event where exposure misclassification is highly uncertain, these methods are of limited use, because the resulting posterior uncertainty intervals tend to be too wide to be informative. Posterior inference also becomes very dependent on the subjectively elicited prior distribution. In this paper, we propose an alternative "robust Bayesian" approach, where instead of eliciting prior distributions for the misclassification probabilities, a feasible region is given. The extrema of posterior inference within the region are sought using an inequality constrained optimization algorithm. This method enables sensitivity analyses to be conducted in a useful way as we do not need to restrict all of our unknown parameters to fixed values, but can instead consider ranges of values at a time.

  8. Risk factors associated with nephrolithiasis: a case-control study in China.

    PubMed

    Zhao, Ai; Dai, Meng; Chen, Yu Juan; Chang, Hong En; Liu, Ai Ping; Wang, Pei Yu

    2015-03-01

    Nephrolithiasis is a multifactorial disease. The authors conducted a case-control study in China to explore its associated risk factors. A total of 725 nephrolithiasis patients and 553 controls were asked to complete a questionnaire that asked for information about psychological, behavioral, and dietary factors along with a physical and blood biochemical examination. For men, higher education was negatively associated with nephrolithiasis (odds ratio [OR] = 0.6; 95% confidence interval [CI] = 0.4-1.0), whereas hypso-waist-to-hip ratio (hypso-WHR), defined as WHRs >0.9 for men and >0.8 for women (OR = 2.2; 95% CI = 1.4-3.4); overexercise (OR = 2.1; 95% CI = 1.3-3.5); and having experienced negative life events (OR = 2.2; 95% CI = 1.2-4.1) were positively associated with nephrolithiasis. For women, higher fluid intake was negatively associated with nephrolithiasis (OR = 0.6; 95% CI = 0.3-0.9), and abnormal status of blood pressure (BP) and blood lipids was positively associated with nephrolithiasis. Varied factors were related to differences in nephrolithiasis occurrence between genders. Besides taking enough fluids, maintaining a normal metabolic status, avoiding overexercise, and reducing BP might be beneficial in preventing nephrolithiasis.

  9. Soft tissue sarcoma and military service in Vietnam: a case-control study

    SciTech Connect

    Kang, H.; Enziger, F.; Breslin, P.; Feil, M.; Lee, Y.; Shepard, B.

    1987-10-01

    A case-control study was conducted in men who were of draftable age during the Vietnam conflict to examine the association of soft tissue sarcomas (STSs) with military service in Vietnam as well as other host and environmental risk factors. A total of 217 STS cases selected from the Armed Forces Institute of Pathology were compared to 599 controls for Vietnam service, occupational and nonoccupational exposure to various chemicals, occupational history, medical history, and life-style (smoking, alcohol, coffee, etc.). Military service information was verified by a review of the patient's military personnel records. Other information was ascertained from a telephone interview with either subjects or their next of kin. Cases and controls were stratified on the basis of the hospital type (civilian, Veterans Administration, and military); the Mantel-Haenszel estimate of the odds ratio (OR), adjusted for the effects of the stratification variable, was calculated. Vietnam veterans in general did not have an increased risk of STS when compared to those men who had never been in Vietnam (OR, 0.85; 95% confidence interval, 0.54-1.36). Subgroups of Vietnam veterans who had higher estimated opportunities for Agent Orange exposure seemed to be at greater risk of STSs when their counterparts in Vietnam were taken as a reference group. However, this risk was not statistically significant.

  10. Total serum IgE concentration in patients with psoriasis: a case-control study.

    PubMed

    Lajevardi, Vahideh; Ghiasi, Maryam; Goodarzi, Azadeh; Mohtasham, Sima; Ansari, Mahsa; Hedayat, Kosar; Nassiri, Farzad

    2014-01-01

    Psoriasis is a chronic relapsing disorder that involves the skin, nails and joints. With regard to the role of the immune system in psoriasis, the current study compared serum IgE concentration in patients with psoriasis with control group. Current case-control study was conducted in Dermatology clinic of Razi hospital, Tehran University of medical sciences, Tehran, Iran in 2012. Fifty-eight patients with psoriasis e referred to the clinic were assigned as patient group and 58 healthy subjects with matched age and sex as a control group. Patient's history, family history and demographic characteristics such as age and sex, duration and severity of disease using PASI, were collected and entered into a form. Consent form was obtained from participants. Serum IgE concentrations of both study groups were measured by electrochemiluminescence assay in the laboratory A total number of 58 patients with psoriasis, mean age of 44.15 (19-76 years) and 58 controls with matched age and sex were studied. Mean average of serum IgE concentration in the control group was 115.13 versus 200/06 concentration in patients group (P=0.16). Serum IgE concentration in 22.4% of patients versus 17.2% in controls was greater than normal concentration (P=0.48). No significant correlation was between serum IgE concentration and disease severity using PASI (P=0.11, r=0.21), neither a significant correlation with disease duration, age and gender. According to the present study, serum IgE concentrations are not greater in patients with psoriasis. IgE concentration is also not associated with the severity of psoriasis based on the PASI score, therefore, the role of IgE in psoriasis can be considered insignificant as some previous studies indicate.

  11. Case-control study of breast cancer in south east England: nutritional factors

    PubMed Central

    Cade, J.; Thomas, E.; Vail, A.

    1998-01-01

    OBJECTIVES: To explore dietary risk factors, in particular fat intake, for breast cancer, using an approach to reduce recall bias of subjects and so provide a more reliable estimate of dietary intake than previous similar studies. DESIGN: A case-control study of women aged 50-65 years attending the breast assessment clinics of the breast screening programme in Southampton and Portsmouth, southern England. Data were analysed for all women requiring further clinical procedures; all women recalled to have an early rescreen; and a random sample of women found to be normal and referred for a routine rescreening appointment (standard recall). MEASUREMENTS: An interview obtained information on various lifestyle characteristics including smoking and alcohol intake, weight, waist, and hip measurements were also taken at the clinic. Women were given a detailed questionnaire on food intake to complete at home and return by post. RESULTS: 1577 women were included in the study: 220 with breast cancer (cases); 179 with benign breast disease; 353 early rescreen and 825 given a standard recall appointment. There were few differences in nutritional intake between the four groups. Logistic regression analyses were carried out comparing the dietary intake of cases with that of each control group adjusting for important demographic and reproductive factors. Results for the case and standard recall comparison are presented. The only non-calorific nutrient to reach significance was iron, which was negatively associated with risk (p = 0.03). For fat intake, the odds decreased with increasing polyunsaturated fat (p = 0.15), showed no trend with monounsaturated fat (p = 0.37) and increased (p = 0.10) with increasing saturated fat. No pattern was clear for the other calorie providing nutrients. CONCLUSIONS: In line with recent cohort studies, this study has shown no evidence to support the hypothesis that dietary fat is an important contributor to breast cancer rates. Biases should have

  12. Periostin - A Novel Systemic Biomarker for Eosinophilic Airway Inflammation: A Case Control Study

    PubMed Central

    Emprm, Viswanathan; Rajanandh, MG

    2016-01-01

    Introduction Chronic airway inflammation and remodelling are fundamental features of asthma. The molecular phenotypes in asthma are Th2 high and Th2 low. Serum periostin is a biomarker which aid in understanding Th2 high eosinophilic asthma. Aim The present study aimed to identify whether or not serum periostin is a systemic biomarker for eosinophilic airway inflammation in asthmatics. Materials and Methods The study was designed as a prospective, case control study. Patients who presented with consistent symptoms of asthma and confirmed by spirometry with reversibility were the cases. The controls were healthy subjects who had no history of lung disease with normal lung function. The sputum and blood samples were collected from both the groups. Sputum eosinophils, Absolute Eosinophil Counts (AEC) and serum periostin levels were compared between the groups. Results The study comprised of 101 participants in which 30 were controls and 71 were cases. In the study group, mean post FEV1 was 64.45. There was a positive correlation of sputum eosinophils with severity of obstruction. The ROC curve analysis showed the cut-off value of 24.556 for serum periostin with the p-value of <0.001. As the severity of obstruction increased, the serum periostin levels were also found to be increased. Serum periostin had a sensitivity and specificity of 97.18% and 86.67% with a diagnostic accuracy of 94.06%. Conclusion Serum periostin appears to be a more sensitive tool for detection of airflow limitation in asthmatic patients with a Th2 high eosinophilic phenotype when compared to AEC and sputum eosinophils. PMID:27054127

  13. Smoking during Pregnancy and Attention-Deficit/Hyperactivity Disorder, Predominantly Inattentive Type: A Case-Control Study

    ERIC Educational Resources Information Center

    Schmitz, Marcelo; Denardin, Daniel; Silva, Tatiana Laufer; Pianca, Thiago; Hutz, Mara Helena; Faraone, Stephen; Rohde, Luis Augusto

    2006-01-01

    Objective: Few previous studies assessed specifically attention-deficit/hyperactivity disorder, predominantly inattentive subtype (ADHD-I) in nonreferred samples. This study investigated the association between ADHD-I and prenatal exposure to nicotine. Method: In a case-control study performed between September 2002 and April 2005, we assessed a…

  14. Case-control study on childhood cancer in the vicinity of nuclear power plants in Germany 1980-2003.

    PubMed

    Spix, Claudia; Schmiedel, Sven; Kaatsch, Peter; Schulze-Rath, Renate; Blettner, Maria

    2008-01-01

    The 1984 Windscale study raised concern about a possible association between living in the vicinity of nuclear power plants and childhood cancer. No such effect for all cancers was seen in ecological studies in Germany (1980-1995). Results from exploratory analyses led to a new study. Pre-selected areas around all 16 major nuclear power plants in Germany formed the study area. The design is a matched case-control study; cases are all cancers under five years diagnosed in 1980-2003: 1592 cases, and 4735 controls. Inverse distance of place of residence to the nearest nuclear power plant at the time of diagnosis was used as the independent variable in a conditional logistic regression model. Results show an increased risk for childhood cancer under five years when living near nuclear power plants in Germany. The inner 5-km zone shows an increased risk (odds ratio 1.47; lower one-sided 95% confidence limit 1.16). The effect was largely restricted to leukaemia. The results are compatible with the corresponding subgroups in the previous German ecological studies, with which this study shares most of the cases. They contrast with the lack of an effect observed or expected from other studies due to low doses from routine nuclear power plant operation.

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

    PubMed

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

    2017-04-06

    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 trend<0·01) for total phytosterols. 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.

  16. A case-control study of occupational sunlight exposure and renal cancer risk.

    PubMed

    Karami, Sara; Colt, Joanne S; Stewart, Patricia A; Schwartz, Kendra; Davis, Faith G; Ruterbusch, Julie J; Chow, Wong-Ho; Wacholder, Sholom; Graubard, Barry I; Purdue, Mark P; Moore, Lee E

    2016-04-01

    Epidemiological evidence of a relationship between vitamin D and kidney cancer risk has been inconsistent despite experimental data indicating that vitamin D and its metabolites may inhibit carcinogenesis. Previously we reported an inverse association between renal cell carcinoma (RCC) risk and occupational ultraviolet (UV) exposure among European men. In this study, we examined the association between occupational UV exposure and RCC risk among US residents and investigated whether this association varied by race and sex. Lifetime occupational data for 1,217 RCC cases and 1,235 controls in a population-based case-control study, conducted from 2002 to 2007, were assessed for occupational UV exposure. We evaluated exposure metrics in quartiles based on control exposure levels and calculated associations between RCC risk and occupational UV exposure using unconditional logistic regression adjusted for sex, race, body mass index, smoking, hypertension, center, education, family history of cancer and dietary vitamin D intake. A general pattern of decreasing RCC risk with increasing UV exposure was observed. Cases had significantly lower cumulative occupational UV exposure than controls (fourth quartile vs. first: odds ratio = 0.74 [95% confidence interval = 0.56-0.99], p-trend = 0.03). Similar results were observed for other UV exposure metrics. The association with occupational UV exposure was stronger for women than for men, but did not differ by race. Our findings suggest an inverse association between occupational UV exposure and RCC, particularly among women. Given the sex finding discrepancies in this study versus our previous study, additional research is need to clarify whether the protective effects of occupational UV exposure and RCC risk are real.

  17. Iron-deficiency Anemia in Children with Febrile Seizure: A Case-Control Study

    PubMed Central

    GHASEMI, Fateme; VALIZADEH, Fateme; TAEE, Nadere

    2014-01-01

    Objective Considering the recurrence of febrile seizure and costs for families, many studies have attempted to identify its risk factors. Some recent studies have reported that anemia is more common in children with febrile convulsion, whereas others have reported that iron deficiency raises the seizure threshold. This study was done to compare iron-deficiency anemia in children with first FS with children having febrile illness alone and with healthy children. Materials & Methods This case-control study evaluated 300 children in three groups (first FS, febrile without convulsion, and healthy) in Khoramabad Madani Hospital from September 2009 to September 2010. Body temperature on admission was measured using the tympanic method. CBC diff, MCV, MCH, MCHC, serum iron, plasma ferritin and TIBC tests were performed for all participants. Data were analyzed by frequency, mean, standard deviation, ANOVA, and chi-square statistical tests. Odds ratios were estimated by logistic regression at a confidence level of 95%. Results Forty percent of the cases with FS had iron-deficiency anemia, compared to 26% of children with febrile illness without seizure and 12% of healthy children. The Odds ratio for iron-deficiency anemia in the patients with FS was 1.89 (95% CI, 1.04-5.17) compared to the febrile children without convulsion and 2.21 (95% CI, 1.54-3.46) compared to the healthy group. Conclusion Children with FS are more likely to be iron-deficient than those with febrile illness alone and healthy children. Thus, iron-deficiency anemia could be a risk factor for FS. PMID:24949050

  18. Risk Factor of Preterm Labor in the West of Iran: A Case-Control Study

    PubMed Central

    DERAKHSHI, Bahareh; ESMAILNASAB, Nader; GHADERI, Ebrahim; HEMMATPOUR, Siroos

    2014-01-01

    Abstract Background Prematurity is the most common cause of neonatal death. Risk factors of premature birth can be related with ethnicity and genetic. There is no comprehensive high sample size study in Kurdish ethnicity to determine risk factors related to prematurity. This study evaluated risk factors of preterm labor in Kurdish ethnicity. Methods This case-control study was conducted in 200 preterm infants (case group) and 400 term infants (control group), in Besat Hospital, Sanandaj, Iran, in the year 2012. Data was analyzed using SPSS software and analysis was performed by Chi-square, Mann-Whitney and logistic regression tests. Results In univariate analysis, mother’s own prematurity, history of previous preterm labor, prematurity in the first-degree family members, history of dead children, premature rupture of membranes, multiple pregnancies, overt diabetes, chronic hypertension, preeclampsia and eclampsia, infertility and cervical incompetence had significant relation-ship with preterm labor. However, multivariate analysis results showed that abnormal amniotic fluid, premature rupture of membranes, double and multiple pregnancies, chronic hypertension, family history of premature birth, mothers age over 35 years, and cervical incompetence (P<0.05) had significant relationship with the premature birth. Conclusion Screening of newborns at risk of preterm labor could be achieved by these risk factors: family history of prematurity, mother’s own history of prematurity and previous preterm labor, history of previous neonatal death, decreased amniotic fluid, multiple pregnancies, overt diabetes, hypertension, preeclampsia, infertility and cervical incompetence, however some of these factors are not the direct cause of prematurity. Our study suggests genetic’ s role in preterm labor. PMID:26005661

  19. Risk Factors for Thyroid Cancer: A Hospital-Based Case-Control Study in Korean Adults

    PubMed Central

    Myung, Seung-Kwon; Lee, Chan Wha; Lee, Jeonghee; Kim, Jeongseon; Kim, Hyeon Suk

    2017-01-01

    Purpose Although the incidence of thyroid cancer in Korea has rapidly increased over the past decade, few studies have investigated its risk factors. This study examined the risk factors for thyroid cancer in Korean adults. Materials and Methods The study design was a hospital-based case-control study. Between August 2002 and December 2011, a total of 802 thyroid cancer cases out of 34,211 patients screened from the Cancer Screenee. Cohort of the National Cancer Center in South Korea were included in the analysis. A total of 802 control cases were selected from the same cohort, and matched individually (1:1) by age (±2 years) and area of residence for control group 1 and additionally by sex for control group 2. Results Multivariate conditional logistic regression analysis using the control group 1 showed that females and those with a family history of thyroid cancer had an increased risk of thyroid cancer, whereas ever-smokers and those with a higher monthly household income had a decreased risk of thyroid cancer. On the other hand, the analysis using control group 2 showed that a family history of cancer and alcohol consumption were associated with a decreased risk of thyroid cancer, whereas higher body mass index (BMI) and family history of thyroid cancer were associated with an increased risk of thyroid cancer. Conclusion These findings suggest that females, those with a family history of thyroid cancer, those with a higher BMI, non-smokers, non-drinkers, and those with a lower monthly household income have an increased risk of developing thyroid cancer. PMID:27338034

  20. Correlates of Excessive Daytime Sleepiness in De Novo Parkinson's Disease: A Case Control Study

    PubMed Central

    Simuni, Tanya; Caspell-Garcia, Chelsea; Coffey, Christopher; Chahine, Lama M.; Lasch, Shirley; Oertel, Wolfgang H.; Mayer, Geert; Högl, Birgit; Postuma, Ron; Videnovic, Aleksandar; Amara, Amy Willis; Marek, Ken

    2016-01-01

    Objective This study was undertaken to determine the frequency and correlates of excessive daytime sleepiness in de novo, untreated Parkinson's disease (PD) patients compared with the matched healthy controls. Methods Data were obtained from the Parkinson's Progression Markers Initiative, an international study of de novo, untreated PD patients and healthy controls. At baseline, participants were assessed with a wide range of motor and nonmotor scales, including the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS). Excessive daytime sleepiness was assessed based on the Epworth Sleepiness scale (ESS), with a cutoff of 10. Results Four hundred twenty-three PD subjects and 196 healthy controls were recruited into the study. Mean ESS (min, max) score was 5.8 (0, 20) for the PD subjects and 5.6 (0, 19) for healthy controls (P = 0.54). Sixty-six (15.6%) PD subjects and 24 (12%) healthy controls had ESS of at least 10 (P = 0.28). No difference was seen in demographic characteristics, age of onset, disease duration, PD subtype, cognitive status, or utilization of sedatives between the PD sleepiness-positive versus the negative group. The sleepiness-positive group had higher MDS-UPDRS Part I and II but not III scores, and higher depression and autonomic dysfunction scores. Sleepiness was associated with a marginal reduction of A-beta (P = 0.05) but not alpha-synuclein spinal fluid levels in PD. Conclusions This largest case control study demonstrates no difference in prevalence of excessive sleepiness in subjects with de novo untreated PD compared with healthy controls. The only clinical correlates of sleepiness were mood and autonomic dysfunction. Ongoing longitudinal analyses will be essential to further examine clinical and biological correlates of sleepiness in PD and specifically the role of dopaminergic therapy. PMID:26095202

  1. PERIODONTAL DISEASE IS ASSOCIATED WITH GESTATIONAL DIABETES MELLITUS: A CASE-CONTROL STUDY

    PubMed Central

    Xiong, Xu; Elkind-Hirsch, Karen E.; Vastardis, Sotirios; Delarosa, Robert L.; Pridjian, Gabriella; Buekens, Pierre

    2010-01-01

    Background Few studies have specifically examined the relationship between periodontal disease and gestational diabetes mellitus (GDM). The objective of this study was to examine whether maternal periodontal disease is associated with GDM. Methods A case-control study was conducted of 53 pregnant women with GDM and 106 pregnant women without GDM at Woman’s Hospital, Baton Rouge, USA. The periodontal examinations were performed by a calibrated dentist who was blinded on the diabetic status of the pregnant women. Periodontitis was defined as the presence of any site with a probing depth (PD) ≥ 4 mm or a clinical attachment loss (CAL) ≥ 4 mm. The severity of periodontal disease was measured in quartiles of PD and CAL. Univariable analysis and multivariable logistic regression were used to examine the relationships between periodontal disease and GDM. Results The percentage of periodontitis was 77.4% in women with GDM and 57.5% in pregnant non-GDM women, with an odds ratio (OR) and 95% confidence interval (CI) of 2.5 (1.2–5.3). After adjusting for confounding variables of maternal age, parity, race, marital status, education, family income, smoking, alcohol consumption, systemic antibiotics in pregnancy, family history of diabetes, income, dental insurance coverage and body mass index, the adjusted OR (95% CI) was 2.6 (1.1–6.1). The adjusted ORs (95% CIs) of GDM comparing the highest-to-lowest quartiles of PD and CAL were 3.8 (1.0–14.0) and 4.5 (1.2–16.9). Conclusion This study supports the hypothesis of an association between periodontal disease and GDM. PMID:19905944

  2. Determinants of infant nutritional status in Dabat district, North Gondar, Ethiopia: A case control study

    PubMed Central

    Wubante, Amarech Asratie

    2017-01-01

    Background Malnutrition is the top cause of global burden of disease, disability and mortality among infants. Over two-thirds of deaths of children globally occur during the first year of life (infancy). Malnutrition among infants is substantially high in Ethiopia. Therefore, this study is aimed to assess determinants of infant nutritional status. Methods A community based nested case-control study was conducted from February to June 2013 in Dabat district. A total of 80 cases and 320 controls (1:4 ratios) were studied. Relevant data was extracted from the community based survey data set. Anthroplus software was used to identify cases and controls. Determinants of infant nutritional status were identified using multivariate analysis. Results Among the total of 80 cases and 320 controls, more than half (52.5%) of the cases and the controls (53.8%) were males and females, respectively. Breast Feeding (BF) was started immediately after birth in only 43.8% of the cases. Nearly 94% of the mothers of the cases had no breast feeding information as part of Ante Natal Care (ANC) follow up. Maternal age (AOR: 0.29; 95% CI: 0.11–0.76), having radio (AOR: 0.43; 95% CI: 0.22–0.82), lack of toilet facility (AOR: 2.24; 95% CI: 1.16–4.33), deprivation of colostrum (AOR: 1.76; 95% CI: 1.01–1.06) and method of complementary feeding (AOR: 2.82; 95% CI: 1.33–5.99) were associated with wasting. Conclusions This study has found that inappropriate infant feeding; nutritional information gap and lack of toilet facility as significant predictors of malnutrition. Hence, joint interventions, including counseling of mothers about benefits of colostrum feeding and use of appropriate feeding method, toilet utilization and mass media such as radio possession, are needed to address the problem in Dabat district. PMID:28346497

  3. Gender Specific Association of RAS Gene Polymorphism with Essential Hypertension: A Case-Control Study

    PubMed Central

    Dhanachandra Singh, Kh.; Jajodia, Ajay; Kaur, Harpreet; Kukreti, Ritushree; Karthikeyan, Muthusamy

    2014-01-01

    Renin-angiotensin system (RAS) polymorphisms have been studied as candidate risk factors for hypertension with inconsistent results, possibly due to heterogeneity among various genetic and environmental factors. A case-control association study was conducted to investigate a possible involvement of polymorphisms of three RAS genes: AGT M235T (rs699), ACE I/D (rs4340) and G2350A (rs4343), and AGTR1 A1166C (rs5186) in essential hypertensive patients. A total of 211 cases and 211 controls were recruited for this study. Genotyping was performed using PCR-RFLP method. The genotype and allele distribution of the M235T variant differed significantly in hypertensives and normotensives (OR-CI = 2.62 (1.24–5.76), P = 0.006; OR-CI = 0.699 (0.518–0.943), P = 0.018), respectively. When the samples were segregated based on sex, the 235TT genotype and T allele were predominant in the female patients (OR-CI = 5.68 (1.60-25.10), P = 0.002; OR-CI = 0.522 (0.330–0.826), P = 0.005) as compare to the male patients (OR-CI = 1.54 (1.24–5.76), P = 0.34; OR-CI = 0.874 (0.330–0.826), P = 0.506), respectively. For ACE DD variant, we found overrepresentation of “I”-allele (homozygous II and heterozygous ID) in unaffected males which suggest its protective role in studied population (OR-CI = 0.401 (0.224–0.718); P = 0.0009). The M235T variant of the AGT is significantly associated with female hypertensives and ACE DD variant could be a risk allele for essential hypertension in south India. PMID:24860821

  4. A cholera outbreak in Alborz Province, Iran: a matched case-control study

    PubMed Central

    2016-01-01

    OBJECTIVES: A total of 229 confirmed cholera cases were reported in Alborz Province during an outbreak that lasted from June 2011 to August 2011. This study aimed to identify potential sources of transmission in order to determine suitable interventions in similar outbreaks. In other words, the lessons learned from this retrospective study can be utilized to manage future similar outbreaks. METHODS: An age-matched and sex-matched case-control study was conducted during the outbreak. For each case, two control subjects were selected from the neighborhood. A case of cholera was defined as a bacteriologically confirmed case with signs and symptoms of cholera. This study was conducted from June 14, 2011 through August 23, 2011. The data were analyzed by calculating odds ratios (ORs) using the logistic regression method. RESULTS: In this outbreak, 229 confirmed cholera cases were diagnosed. The following risk factors were found to be associated with cholera: consumption of unrefrigerated leftover food (OR, 3.05; 95% confidence interval [CI], 1.72 to 5.41), consumption of vegetables and fruits in the previous three days (OR, 2.75; 95% CI, 1.95 to 3.89), and a history of traveling in the previous five days (OR, 5.31; 95% CI, 2.21 to 9.72). CONCLUSIONS: Consumption of vegetables and fruits has remained an unresolved risk factor in cholera outbreaks in Iran in recent years. In order to reduce the risk of cholera, sanitary standards for fruits and vegetables should be observed at all points from production to consumption, the population should be educated regarding hygienic food storage during outbreaks, and sanitary standards should be maintained when traveling during cholera outbreaks. PMID:27188308

  5. Lifestyle factors and breast cancer: a case-control study in Kuala Lumpur, Malaysia.

    PubMed

    Kamarudin, Rozanim; Shah, Shamsul Azhar; Hidayah, Noor

    2006-01-01

    Breast cancer is the most common female cancer and the commonest cause of death due to cancer for women in Malaysia. This study was performed to identify the relationship with lifestyle factors. A case-control study was conducted among females with breast cancer who came for treatment to the Breast Clinic Hospital Kuala Lumpur in July until September 2004. A total of 203 female patients were recruited as cases along with 203 patients who attended the Outpatient Clinic, Hospital Kuala Lumpur during the study period as the controls. The study showed women who did not exercise regularly to have four times higher risk (adjusted odds ratio is 3.49, 95% CI is 1.84 to 6.62) compared to those who exercised regularly. Women with a high fat diet were also at elevated risk (adjusted odds ratio 3.84, 95% CI is 1.20 to 12.34) compared to those consuming a low fat diet. Women without breast cancer generally had a longer duration of lifetime lactation with a median of thirty-three months compared to women with breast cancer (twenty months, p<0.05). Women who did not take oral contraceptive pills but had breast-fed their child have a 56.0% lower risk (crude odds ratio 0.44, CI is 0.22 to 0.87) compared to women who did not take oral contraceptive pill and also did not breast-feed their child. If they had breast fed for thirteen months and above, they faced a 61.0% lower risk (crude odds ratio 0.39, 95% CI is 0.17 to 0.87). There was a significant inverse trend for lifetime lactation and breast cancer risk. In conclusion certain life styles of women are associated with a higher risk of breast cancer development. Therefore, the promotion of a healthy life style should be emphasized.

  6. A microsurgical anterior cervical approach and the immediate impact of mechanical retractors: A case control study

    PubMed Central

    Ramos-Zúñiga, Rodrigo; Díaz-Guzmán, Laura Rocío; Velasquez, Shannen; Macías-Ornelas, Ana Magdalena; Rodríguez-Vázquez, Martín

    2015-01-01

    Introduction: A microsurgical anterior cervical approach with discectomy and fusion (MACDF) is one of the most widely used procedures for treating radicular disorders. This approach is highly successful; however, it is not free from complications. These can be associated with soft tissue injuries. Aim of the Study: The recognition of the risks for these complications should be identified for timely prevention and safe treatment. Materials and Methods: Study Design: Retrospective case control study. This study includes a retrospective case series of 37 patients, paying special attention to immediate complications related to the use of mechanical retraction of soft tissue (dysphagia, dysphonia, esophageal lesions and local hematoma); and a comparative analysis of the outcomes after changes in the retraction method. Results: All selected cases had a positive neurological symptom response in relation to neuropathic pain. Dysphagia and dysphonia were found during the first 72 h in 94.1% of the cases in which automatic mechanical retraction was used for more than one hour during the surgical procedure. A radical change was noted in the reduction of the symptoms after the use of only manual protective blades without automatic mechanical retraction: 5.1% dysphagia and 0% dysphonia in the immediate post-operative period, P = 0.001. Conclusions: Soft tissue damage due to the use of automatic retractors in MACDF is not minor and leads to general discomfort in the patient in spite of good neurological results. These problems most often occur when automatic retractors are used continuously for more than 1 hour, as well as when they are used in multiple levels. Dysphagia, dysphonia and local pain decreased with the use of transient manual blades for retraction, and with intermittent release following minimally invasive principles. PMID:26167011

  7. Metabolic disorders and the risk of nasopharyngeal carcinoma: a case-control study in Italy.

    PubMed

    Zucchetto, Antonella; Taborelli, Martina; Bosetti, Cristina; Montella, Maurizio; La Vecchia, Carlo; Franchin, Gianni; Libra, Massimo; Serraino, Diego; Polesel, Jerry

    2016-07-29

    The aim of this study is to evaluate the association between metabolic disorders and the risk of nasopharyngeal carcinoma, considering different histological subtypes. Between 1992 and 2008, we carried out a multicentre case-control study in Italy. One-hundred and ninety-seven White patients with histologically confirmed nasopharyngeal carcinoma were enrolled as cases. The control group included 592 cancer-free patients, frequency matched by study centre, area of residence, sex, age and period of interview. Odds ratios (OR) and corresponding 95% confidence intervals (CI), for nasopharyngeal carcinoma according to obesity and self-reported history of other metabolic disorders, were calculated through logistic regression models adjusted for matching variables and tobacco smoking and drinking habits. Obesity (OR=1.44; 95% CI: 0.88-2.36), diabetes mellitus (OR=0.91; 95% CI: 0.42-1.98), hypertension (OR=0.79; 95% CI: 0.48-1.32), hypercholesterolaemia (OR=1.41; 95% CI: 0.84-2.35) and metabolic syndrome (i.e. at least three among the four previously cited metabolic disorders; OR=1.11; 95% CI: 0.86-1.43) were not significantly associated with the overall risk of nasopharyngeal carcinoma. However, the associations observed for diabetes mellitus, hypercholesterolaemia and metabolic syndrome were stronger among differentiated nasopharyngeal carcinomas than among undifferentiated ones. In particular, 21.7% of differentiated nasopharyngeal carcinoma cases and 7.8% of controls reported a history of metabolic syndrome (OR=3.37; 95% CI: 1.05-10.81). The results of the study indicated no overall association between metabolic disorders and nasopharyngeal carcinoma. Nonetheless, although the small sample size calls for caution in interpretation, metabolic disorders could increase the risk of differentiated nasopharyngeal carcinoma. This finding further supports a different aetiology of the two histological subtypes.

  8. Water nitrates and CNS birth defects: a population-based case-control study

    SciTech Connect

    Arbuckle, T.E.; Sherman, G.J.; Corey, P.N.; Walters, D.; Lo, B.

    1988-03-01

    The relation between maternal exposure to nitrates in drinking water and risk of delivering an infant with a central nervous system (CNS) malformation was examined by means of a case-control study in New Brunswick, Canada. All cases of CNS defects for a high and a low prevalence area of New Brunswick, for the years 1973-1983, were included in the study. Controls were selected randomly from the livebirth files for the province, matched on county of maternal residence and date of birth. One hundred and thirty (130) cases were identified and individually matched with two controls each. Individual water samples were collected from the case and control mother's address given on the birth or stillbirth records. The study revealed that the effect of nitrate exposure in water was modified by whether the source of the drinking water was a private well or a public municipal distribution system. Compared to a baseline nitrate level of 0.1 ppm, exposure to nitrate levels of 26 ppm from private well water sources was associated with a moderate, but not statistically significant, increase in risk (risk odds ratio = 2.30; 95% confidence interval = 0.73-7.29). If the source of drinking water was a municipal distribution system or a private spring, an increase in nitrate exposure was associated with a decrease in risk of delivering a CNS-malformed infant; however, these effect estimates were not statistically significant. The positive increase in risk with nitrate exposure from well water sources requires further study using a larger case series and a larger proportion of exposures to nitrate levels exceeding 5 ppm.

  9. Determinants of mortality from severe dengue in Brazil: a population-based case-control study.

    PubMed

    Moraes, Giselle Hentzy; de Fátima Duarte, Eliane; Duarte, Elisabeth Carmen

    2013-04-01

    Although increases in severity of mortality from dengue infection have been observed in Brazil, their determinants are not fully known. A case-control study was conducted by using the National Notifiable Diseases Surveillance System, including patients with severe dengue during 2000-2005. Cases were defined as patients that died and controls were those who survived. Hierarchical multivariate logistic regression was performed. During the study period, there were 12,321 severe cases of dengue and 1,062 deaths. Factors independently associated with death included age ≥ 50 years (odds ratio [OR] = 2.29, 95% confidence interval [CI] = 1.59-3.29), < 4 years of schooling (OR = 1.83, 95% CI = 1.47-2.28), a rural area (OR =2.84, 95% CI = 2.19-3.69), hospitalization (OR = 1.42, 95% CI = 1.17-1.73), and a high hematocrit (OR = 2.46, 95% CI = 1.85-3.28). Factors associated with a lower chance of dying were female sex (OR = 0.76, 95% CI = 0.67-0.87), history of previous dengue (OR = 0.78, 95% CI = 0.62-0.99), positive tourniquet test result (OR = 0.47, 95% CI = 0.33-0.66), laboratory diagnosis of dengue (OR = 0.75, 95% CI = 0.61-0.92), and a platelet count of 50,000-100,000 cells/mm(3) (OR = 0.56, 95% CI = 0.36-0.87). The risk profile identified in this study should serve to direct public health interventions to minimize deaths.

  10. Psoriasis and Hypertension Severity: Results from a Case-Control Study

    PubMed Central

    Armstrong, April W.; Lin, Steven W.; Chambers, Cynthia J.; Sockolov, Mary E.; Chin, David L.

    2011-01-01

    Background Epidemiologic studies have provided new insights into the association between psoriasis and cardiovascular diseases. Previous population studies have examined hypertension frequency in psoriasis patients. However, the relationship between severity of hypertension and psoriasis has not been characterized. Objective We sought to investigate whether patients with psoriasis have more difficult-to-manage hypertension compared to non-psoriatic hypertensive patients. Approach We performed a case-control study using the University of California Davis electronic medical records. The cases were defined as patients diagnosed with both psoriasis and hypertension, and controls were defined as patients with hypertension and without psoriasis. In this identified population, 835 cases were matched on age, sex, and body mass index (BMI) to 2418 control patients. Key Results Treatment with multiple anti-hypertensives was significantly associated with the presence of psoriasis using univariate (p<0.0001) and multivariable analysis, after adjusting for diabetes, hyperlipidemia, and race (p<0.0001). Compared to hypertensive patients without psoriasis, psoriasis patients with hypertension were 5 times more likely to be on a monotherapy antihypertensive regimen (95% CI 3.607.05), 9.5 times more likely to be on dual antihypertensive therapy (95% CI 6.68–13.65), 16.5 times more likely to be on triple antihypertensive regimen (95% CI 11.01–24.84), and 19.9 times more likely to be on quadruple therapy or centrally-acting agent (95% CI 10.58–37.33) in multivariable analysis after adjusting for traditional cardiac risk factors. Conclusions Psoriasis patients appear to have more difficult-to-control hypertension compared to non-psoriatic, hypertensive patients. PMID:21479272

  11. Predictors of acute diarrhoea among hospitalized children in Gaza Governorates: a case-control study.

    PubMed

    Alnawajha, Samer Khader; Bakry, Ghadeer Abdo; Aljeesh, Yousef Ibrahim

    2015-03-01

    This study aims to determine the predictors of acute diarrhoea among hospitalized children in the Gaza Governorates. The case-control design included 140 children (70 cases and 70 controls) in a stratified cluster sample from Naser Medical Complex and Alnasser Pediatric Hospital. An interview questionnaire was used, and face and content validations were performed. Multiple logistic regression was used for the multivariate analysis of risk factors of diarrhoea in children aged less than five years. Results showed a significant association between diarrhoea and family income, residence, complementary feeding, and age of weaning (p<0.05). Children living in villages had lower odds of having diarrhoea by 53.2% than children living in cities. Children of families with incomes between US$ 485 and 620 had lower odds of having diarrhoea by 80.8% than children of families with incomes less than US$ 485. Moreover, children who did not receive complementary feeding had lower odds of having diarrhoea by 59.0%. We found that, for one month increase in weaning age, the odds of diarrhoea decreased by 1.06 times (adjusted OR=1.05, 95% CI 1.0180-1.100). The study concludes that urban residence, lower family income, complementary feeding, and lower age of weaning are risk factors of diarrhoea among children aged less than five years in the Gaza Strip. The results of the study suggest that children of low-income families and those who were not naturally breastfed may warrant more attention for prevention and/or treatment of diarrhoea.

  12. Childhood autism in India: A case-control study using tract-based spatial statistics analysis

    PubMed Central

    Assis, Zarina Abdul; Bagepally, Bhavani Shankara; Saini, Jitender; Srinath, Shoba; Bharath, Rose Dawn; Naidu, Purushotham R.; Gupta, Arun Kumar

    2015-01-01

    Context: Autism is a serious behavioral disorder among young children that now occurs at epidemic rates in developing countries like India. We have used tract-based spatial statistics (TBSS) of diffusion tensor imaging (DTI) measures to investigate the microstructure of primary neurocircuitry involved in autistic spectral disorders as compared to the typically developed children. Objective: To evaluate the various white matter tracts in Indian autistic children as compared to the controls using TBSS. Materials and Methods: Prospective, case-control, voxel-based, whole-brain DTI analysis using TBSS was performed. The study included 19 autistic children (mean age 8.7 years ± 3.84, 16 males and 3 females) and 34 controls (mean age 12.38 ± 3.76, all males). Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) values were used as outcome variables. Results: Compared to the control group, TBSS demonstrated multiple areas of markedly reduced FA involving multiple long white matter tracts, entire corpus callosum, bilateral posterior thalami, and bilateral optic tracts (OTs). Notably, there were no voxels where FA was significantly increased in the autism group. Increased RD was also noted in these regions, suggesting underlying myelination defect. The MD was elevated in many of the projections and association fibers and notably in the OTs. There were no significant changes in the AD in these regions, indicating no significant axonal injury. There was no significant correlation between the FA values and Childhood Autism Rating Scale. Conclusion: This is a first of a kind study evaluating DTI findings in autistic children in India. In our study, DTI has shown a significant fault with the underlying intricate brain wiring system in autism. OT abnormality is a novel finding and needs further research. PMID:26600581

  13. Risk factors for multidrug-resistant tuberculosis among tuberculosis patients: a case-control study

    PubMed Central

    Workicho, Abdulhalik; Kassahun, Wondwosen; Alemseged, Fessahaye

    2017-01-01

    Background Multidrug-resistant tuberculosis (MDR-TB) did not receive major attention until recently in sub-Saharan Africa where the tuberculosis incidence and risk factors are highest. Factors leading to development of drug resistance need to be understood to develop appropriate control strategies for national programs. The objective of this study was to identify the risk factors for MDR-TB among tuberculosis patients. Methods A case-control study was conducted to assess sociodemographic, behavioral and clinical risk factors using a structured questionnaire and clinical record reviewing. The data were entered and analyzed using SPSS windows version 16. Descriptive analysis was done to generate summary values for the variables and those significant variables in the bivariate analysis at p-value less than 0.25 were entered to multivariable logistic regression to identify independent determinants. Statistical significance was declared at p-value less than or equal to 0.05. Results A total of 90 cases and 90 controls were included in the study. Age of respondents (adjusted odds ratio [AOR] =7; 95% confidence interval [CI]: 2.6–24.5), living in a household with only one room (AOR=5; 95%CI: 1.68–15.38), history of previous treatment (AOR=21; 95% CI: 17.8–28) and being HIV infected (AOR=3.1; 95%CI: 1.02–9.4) were found to be independent predictors of MDR-TB. Conclusion In light of these findings, the strategies in controlling MDR-TB should emphasize on patients with HIV coinfection, young patients, those who have a history of previous treatment, and those living in crowded places. PMID:28331350

  14. Aspirin Use Associated With Amyotrophic Lateral Sclerosis: a Total Population-Based Case-Control Study

    PubMed Central

    Tsai, Ching-Piao; Lin, Feng-Cheng; Lee, Johnny Kuang-Wu; Lee, Charles Tzu-Chi

    2015-01-01

    Background The association of aspirin use and nonsteroid anti-inflammatory drug (NSAID) use with amyotrophic lateral sclerosis (ALS) risk is unclear. This study determined whether use of any individual compound is associated with ALS risk by conducting a total population-based case-control study in Taiwan. Methods A total of 729 patients with newly diagnosed ALS who had a severely disabling disease certificate between January 1, 2002, and December 1, 2008, comprised the case group. These cases were compared with 7290 sex-, age-, residence-, and insurance premium-matched controls. Drug use by each Anatomical Therapeutic Chemical code was analyzed using conditional logistic regression models. False discovery rate (FDR)-adjusted P values were reported in order to avoid inflating false positives. Results Of the 1336 compounds, only the 266 with use cases exceeding 30 in our database were included in the screening analysis. Without controlling for steroid use, the analysis failed to reveal any compound that was inversely associated with ALS risk according to FDR criteria. After controlling for steroid use, we found use of the following compounds to be associated with ALS risk: aspirin, diphenhydramine (one of the antihistamines), and mefenamic acid (one of the NSAIDs). A multivariate analysis revealed that aspirin was independently inversely associated with ALS risk after controlling for diphenhydramine, mefenamic acid, and steroid use. The inverse association between aspirin and ALS was present predominately in patients older than 55 years. Conclusions The results of this study suggested that aspirin use might reduce the risk of ALS, and the benefit might be more prominent for older people. PMID:25721071

  15. Socioeconomic factors and the risk of anencephaly in a Mexican population: a case-control study.

    PubMed Central

    Blanco Muñoz, Julia; Lacasaña, Marina; Borja Aburto, Victor Hugo; Torres Sánchez, Luisa Elvira; García García, Ana María; López Carrillo, Lizbeth

    2005-01-01

    OBJECTIVE: The study was designed to evaluate the association between socioeconomic level (as measured by maternal education, maternal occupation, and monthly family income) and anencephaly. METHODS: The authors conducted a case-control study using data from the Epidemiological Surveillance System Register for Neural Tube Defects for three states of the Mexican Republic: Puebla, Guerrero and the State of Mexico. Mothers of 151 cases of infants born with anencephaly and mothers of 151 control infants born during the period March 2000 to February 2001 were interviewed about their socioeconomic characteristics and other factors including reproductive history, use of prenatal care, use of tobacco and alcohol, fever during pregnancy, and folic acid supplementation. RESULTS: After adjustment for potential confounders, a risk gradient was seen with decreasing maternal education. Women with less than a primary school education (adjusted odds ratio [OR]=3.0; 95% confidence interval [CI] 1.2, 7.6) and women who had completed primary school but had not completed junior high school (adjusted OR=2.2; 95% CI 0.9, 5.7) had higher risks of giving birth to an infant with anencephaly, compared to women with a higher educational level. A monthly income < or = 1,000 pesos (approximately dollars 100 U.S.) was also associated with a higher risk of anencephaly (OR=2.5; 95% CI 1.2, 5.1). Women employed in industry or agriculture during the acute risk period (three months prior to conception to one month after conception) had a risk 6.5 times (95% CI 1.4, 29.6) that of professional and business women. CONCLUSIONS: This study helps to identify groups that may be especially vulnerable to this type of congenital malformation so that primary and secondary preventive strategies can be targeted to these groups. PMID:15736330

  16. Determinants of Visceral Leishmaniasis: A Case-Control Study in Gedaref State, Sudan

    PubMed Central

    Salih, Niven; Elhag, Mousab Siddig; Elbadawi, Mobarak Elnour; Hammam, Omer; Mumina, Ann; Atia, Atia Abdalla; Etard, Jean-François; Ritmeijer, Koert; Chappuis, François

    2015-01-01

    Background Improving knowledge on local determinants of visceral leishmaniasis (VL) is crucial to guide the development of relevant control strategies. This study aimed to identify individual and household level determinants of primary VL in 24 highly endemic villages of Tabarak Allah hospital’s catchment area, Gedaref State, Sudan. Methods From September 2012 to July 2013, in an unmatched case-control design, 198 patients with primary VL were compared to 801 controls free of VL symptoms and with a negative VL rapid test. Using random spatial sampling, controls were selected with a distribution of age, sex and village of residence proportionate to the distribution of the target population. Data were collected using a structured questionnaire. Results Children and men were at higher risk of VL. Reporting VL patient(s) in the household in the previous year was the strongest VL risk factor. In a multivariate analysis, VL risk increased with household size, sleep location (outside the yard, not in the farm), evening outdoor activities in the rainy season (playing, watching TV, radio listening), use of ground nut oil as animal repellent and of smoke of Acacia seyal as indoor repellent, presence of dogs in the yard at night, Acacia nilotica in the yard’s immediate surroundings and of a forest at eye range. VL risk appeared to decrease with the use of drinking water sources other than the village water tank, a buffer distance from the adjacent house yard, and with the presence of animals other than dogs in the yard at night. In contrast with previous studies, housing factors, mosquito-net use, black cotton soil, ethnicity, socioeconomic index, presence of Balanites aegyptica and Azadirachta indica in the yard were not independent VL determinants. Discussion and conclusion Although these results do not provide evidence of causality, they provide useful suggestions for guiding further intervention studies on VL preventive measures. PMID:26544177

  17. Occupational exposure to metals and risk of meningioma: a multinational case-control study.

    PubMed

    Sadetzki, Siegal; Chetrit, Angela; Turner, Michelle C; van Tongeren, Martie; Benke, Geza; Figuerola, Jordi; Fleming, Sarah; Hours, Martine; Kincl, Laurel; Krewski, Daniel; McLean, Dave; Parent, Marie-Elise; Richardson, Lesley; Schlehofer, Brigitte; Schlaefer, Klaus; Blettner, Maria; Schüz, Joachim; Siemiatycki, Jack; Cardis, Elisabeth

    2016-12-01

    The aim of the study was to examine associations between occupational exposure to metals and meningioma risk in the international INTEROCC study. INTEROCC is a seven-country population-based case-control study including 1906 adult meningioma cases and 5565 population controls. Incident cases were recruited between 2000 and 2004. A detailed occupational history was completed and job titles were coded into standard international occupational classifications. Estimates of mean workday exposure to individual metals and to welding fumes were assigned based on a job-exposure-matrix. Adjusted odds ratios (ORs) and 95 % confidence intervals (CIs) were estimated using conditional logistic regression. Although more controls than cases were ever exposed to metals (14 vs. 11 %, respectively), cases had higher median cumulative exposure levels. The ORs for ever vs. never exposure to any metal and to individual metals were mostly greater than 1.0, with the strongest association for exposure to iron (OR 1.26, 95 % CI 1.0-1.58). In women, an increased OR of 1.70 (95 % CI 1.0-2.89) was seen for ever vs never exposure to iron (OR in men 1.19, 95 % CI 0.91-1.54), with positive trends in relation with both cumulative and duration of exposure. These results remained after consideration of other occupational metal or chemical co-exposures. In conclusion, an apparent positive association between occupational exposure to iron and meningioma risk was observed, particularly among women. Considering the fact that meningioma is a hormone dependent tumor, the hypothesis that an interaction between iron and estrogen metabolism may be a potential mechanism for a carcinogenic effect of iron should be further investigated.

  18. Hyperemesis gravidarum and maternal cancer risk, a Scandinavian nested case-control study.

    PubMed

    Vandraas, Kathrine F; Grjibovski, Andrej M; Støer, Nathalie C; Troisi, Rebecca; Stephansson, Olof; Ording, Anne Gulbech; Vangen, Siri; Grotmol, Tom; Vikanes, Åse V

    2015-09-01

    Reproductive factors have been shown to influence cancer risk. Several pathological conditions during pregnancy have also been associated with subsequent altered cancer risk in the mother. Hyperemesis gravidarum (hyperemesis) is an early pregnancy condition characterized by severe nausea and vomiting resulting in weight loss and metabolic disturbances. Studies have reported associations between hyperemesis and cancer, but results are inconsistent. In this nested case-control study we linked the population-based medical birth registries and cancer registries in Norway, Sweden and Denmark in order to examine overall cancer risk and risk of specific cancer types in women with a history of hyperemesis, using conditional logistic regression. In total, 168,501 cases of cancer in addition to up to 10 cancer-free controls per case were randomly sampled, matched on year of birth and birth registry (n = 1,721,626). Hyperemesis was defined through the International Classification of Diseases. Analyses were adjusted for potential confounders. Hyperemesis was inversely associated with overall cancer risk with adjusted relative risk (aRR) of 0.93 (95% CI: 0.88-0.99), with cancer in the lungs (aRR: 0.60, 95% CI: 0.44-0.81), cervix (aRR: 0.66, 95% CI: 0.49-0.91) and rectum (aRR: 0.48, 95% CI: 0.29-0.78). Thyroid cancer was positively associated with hyperemesis (aRR 1.45, 95% CI: 1.06-1.99) and risk increased with more than one hyperemetic pregnancy (aRR 1.80, 95% CI: 1.23-2.63). Hormonal factors, in particular human chorionic gonadotropin, are likely to be involved in mediating these effects. This study is the first to systematically address these associations and provides valuable knowledge on potential long-term consequences of hyperemesis.

  19. Severe Sepsis in Severely Malnourished Young Bangladeshi Children with Pneumonia: A Retrospective Case Control Study

    PubMed Central

    Chisti, Mohammod Jobayer; Salam, Mohammed Abdus; Bardhan, Pradip Kumar; Faruque, Abu S. G.; Shahid, Abu S. M. S. B.; Shahunja, K. M.; Das, Sumon Kumar; Hossain, Md Iqbal; Ahmed, Tahmeed

    2015-01-01

    Background In developing countries, there is no published report on predicting factors of severe sepsis in severely acute malnourished (SAM) children having pneumonia and impact of fluid resuscitation in such children. Thus, we aimed to identify predicting factors for severe sepsis and assess the outcome of fluid resuscitation of such children. Methods In this retrospective case-control study SAM children aged 0–59 months, admitted to the Intensive Care Unit (ICU) of the Dhaka Hospital of the International Centre for Diarrhoeal Disease Research, Bangladesh from April 2011 through July 2012 with history of cough or difficult breathing and radiologic pneumonia, who were assessed for severe sepsis at admission constituted the study population. We compared the pneumonic SAM children with severe sepsis (cases = 50) with those without severe sepsis (controls = 354). Severe sepsis was defined with objective clinical criteria and managed with fluid resuscitation, in addition to antibiotic and other supportive therapy, following the standard hospital guideline, which is very similar to the WHO guideline. Results The case-fatality-rate was significantly higher among the cases than the controls (40% vs. 4%; p<0.001). In logistic regression analysis after adjusting for potential confounders, lack of BCG vaccination, drowsiness, abdominal distension, acute kidney injury, and metabolic acidosis at admission remained as independent predicting factors for severe sepsis in pneumonic SAM children (p<0.05 for all comparisons). Conclusion and Significance We noted a much higher case fatality among under-five SAM children with pneumonia and severe sepsis who required fluid resuscitation in addition to standard antibiotic and other supportive therapy compared to those without severe sepsis. Independent risk factors and outcome of the management of severe sepsis in our study children highlight the importance for defining optimal fluid resuscitation therapy aiming at reducing the case

  20. Subfertility and Risk of Testicular Cancer in the EPSAM Case-Control Study

    PubMed Central

    Zugna, Daniela; Fiano, Valentina; Robles Rodriguez, Nena; Maule, Milena; Gillio-Tos, Anna; Ciuffreda, Libero; Lista, Patrizia; Segnan, Nereo; Merletti, Franco; Richiardi, Lorenzo

    2016-01-01

    Background/objectives It has been suggested that subfertility and testicular cancer share genetic and environmental risk factors. We studied both subfertility and the strongest known testicular cancer susceptibility gene, the c-KIT ligand (KITLG), whose pathway is involved in spermatogenesis. Methods The EPSAM case-control study is comprised of testicular cancer patients from the Province of Turin, Italy, diagnosed between 1997 and 2008. The present analysis included 245 cases and 436 controls from EPSAM, who were aged 20 years or older at diagnosis/recruitment. The EPSAM questionnaire collected information on factors such as number of children, age at first attempt to conceive, duration of attempt to conceive, use of assisted reproduction techniques, physician-assigned diagnosis of infertility, number of siblings, and self-reported cryptorchidism. Genotyping of the KITLG single nucleotide polymorphism (SNP) rs995030 was performed on the saliva samples of 202 cases and 329 controls. Results Testicular cancer was associated with the number of children fathered 5 years before diagnosis (odds ratio (OR) per additional child: 0.78, 95% confidence interval (CI): 0.58–1.04) and sibship size (OR per additional sibling: 0.76, 95% CI: 0.66–0.88). When considering the reproductive history until 1 year before diagnosis, attempting to conceive for at least 12 months or fathering a child using assisted reproduction techniques was not associated with the risk of testicular cancer, nor was age at first attempt to conceive or physician-assigned diagnosis of infertility. The SNP rs995030 was strongly associated with risk of testicular cancer (per allele OR: 1.83; 95%CI: 1.26–2.64), but it did not modify the association between number of children and the risk of testicular cancer. Conclusion This study supports the repeatedly reported inverse association between number of children and risk of testicular cancer, but it does not find evidence of an association for other

  1. Safety and Efficacy of Ferric Carboxymaltose in Anemic Pregnant Women: A Retrospective Case Control Study

    PubMed Central

    Pels, Anouk; Ganzevoort, Wessel

    2015-01-01

    Background. Anemia during pregnancy is commonly caused by iron deficiency and can have severe consequences for both the mother and the developing fetus. The aim of this retrospective study was to assess the safety and efficacy of intravenous ferric carboxymaltose (FCM) in pregnant women. Methods. All women treated with FCM for anemia during pregnancy between 2010 and 2012 at our institution were included. A matched control group was selected, including women who either were nonanemic or had anemia but were not considered for intravenous iron. Main outcome measures were maternal safety and pregnancy outcomes. Results. The study included 128 patients (FCM: 64; control: 64). Median FCM dose was 1000 mg and median gestational age at the time of first treatment was 34 weeks and 6 days. Median Hb increased from 8.4 g/dL (interquartile range 7.7; 8.9 g/dL) at the first FCM administration to 10.7 g/dL (9.8; 11.5 g/dL; n = 46 with available Hb at delivery) at the time of delivery, achieving levels similar to those in the control group (10.8 g/dL [9.8; 11.8 g/dL; n = 48]). No treatment-related adverse events were reported and no statistically significant differences in pregnancy outcomes were observed between groups. Conclusions. Within the limitations of this case control study, FCM was a safe and efficient treatment of anemia during pregnancy. PMID:26688686

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

    PubMed

    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.

  3. Robotic single site versus robotic multiport hysterectomy in early endometrial cancer: a case control study

    PubMed Central

    2016-01-01

    Objective To compare surgical outcomes and cost of robotic single-site hysterectomy (RSSH) versus robotic multiport hysterectomy (RMPH) in early stage endometrial cancer. Methods This is a retrospective case-control study, comparing perioperative outcomes and costs of RSSH and RMPH in early stage endometrial cancer patients. RSSH were matched 1:2 according to age, body mass index, comorbidity, the International Federation of Gynecology and Obstetric (FIGO) stage, type of radical surgery, histologic type, and grading. Mean hospital cost per discharge was calculated summarizing the cost of daily hospital room charges, operating room, cost of supplies and length of hospital stay. Results A total of 23 women who underwent RSSH were matched with 46 historic controls treated by RMPH in the same institute, with the same surgical team. No significant differences were found in terms of age, histologic type, stage, and grading. Operative time was similar: 102.5 minutes in RMPH and 110 in RSSH (p=0.889). Blood loss was lower in RSSH than in RMPH (respectively, 50 mL vs. 100 mL, p=0.001). Hospital stay was 3 days in RMPH and 2 days in RSSH (p=0.001). No intraoperative complications occurred in both groups. Early postoperative complications were 2.2% in RMPH and 4.3% in RSSH. Overall cost was higher in RMPH than in RSSH (respectively, $7,772.15 vs. $5,181.06). Conclusion Our retrospective study suggests the safety and feasibility of RSSH for staging early endometrial cancer without major differences from the RMPH in terms of surgical outcomes, but with lower hospital costs. Certainly, further studies are eagerly warranted to confirm our findings. PMID:27171672

  4. Power-Frequency Magnetic Fields and Childhood Brain Tumors: A Case-Control Study in Japan

    PubMed Central

    Saito, Tomohiro; Nitta, Hiroshi; Kubo, Osami; Yamamoto, Seiichiro; Yamaguchi, Naohito; Akiba, Suminori; Honda, Yasushi; Hagihara, Jun; Isaka, Katsuo; Ojima, Toshiyuki; Nakamura, Yosikazu; Mizoue, Tetsuya; Ito, Satoko; Eboshida, Akira; Yamazaki, Shin; Sokejima, Shigeru; Kurokawa, Yoshika; Kabuto, Michinori

    2010-01-01

    Background The strength of the association between brain tumors in children and residential power-frequency magnetic fields (MF) has varied in previous studies, which may be due in part to possible misclassification of MF exposure. This study aimed to examine this association in Japan by improving measurement techniques, and by extending measurement to a whole week. Methods This population-based case-control study encompassed 54% of Japanese children under 15 years of age. After excluding ineligible targeted children, 55 newly diagnosed brain tumor cases and 99 sex-, age-, and residential area-matched controls were included in the analyses. The MF exposures of each set of matching cases and controls were measured in close temporal proximity to control for seasonal variation; the average difference was 12.4 days. The mean interval between diagnosis and MF measurements was 1.1 years. The weekly mean MF level was defined as the exposure. The association was evaluated using conditional logistic regression analysis that controlled for possible confounding factors. Results The odds ratios (95% CI) for exposure categories of 0.1 to 0.2, 0.2 to 0.4, and above 0.4 µT, against a reference category of <0.1 µT, were 0.74 (0.17–3.18), 1.58 (0.25–9.83), and 10.9 (1.05–113), respectively, after adjusting for maternal education. This dose-response pattern was stable when other variables were included in the model as possible confounding factors. Conclusions A positive association was found between high-level exposure—above 0.4 µT—and the risk of brain tumors. This association could not be explained solely by confounding factors or selection bias. PMID:19915304

  5. ABO blood group system and gastric cancer: a case-control study and meta-analysis.

    PubMed

    Wang, Zhiwei; Liu, Lei; Ji, Jun; Zhang, Jianian; Yan, Min; Zhang, Jun; Liu, Bingya; Zhu, Zhenggang; Yu, Yingyan

    2012-10-17

    This study focuses on the association between the ABO blood group system and the risk of gastric cancer or Helicobacter pylori infection. The data for the ABO blood group was collected from 1045 cases of gastric cancer, whereby the patient underwent a gastrectomy in Ruijin Hospital, Shanghai. The information on the ABO blood group from 53,026 healthy blood donors was enrolled as control. We searched the Pubmed database on the relationship between ABO blood groups and gastric cancer risk for meta-analysis. In our case-control study, the risk of gastric cancer in blood group A was significantly higher than that in non-A groups (O, B and AB) (odd ratio, OR1.34; 95% confidential interval, CI 1.25-1.44). Compared with non-O groups (A, B and AB), individuals with blood group O demonstrated a reduced risk of gastric cancer (OR = 0.80; 95% CI 0.72-0.88). The proportion of H. pylori infection in blood group A individuals was significantly higher than that in non-A blood groups (OR = 1.42; 95% CI 1.05-1.93). We further combined our data with the published data of others, and crossreferenced the risk of gastric cancer with the blood type, finding consistent evidence that gastric cancer risk in the blood A group was higher than that in the non-A groups (OR = 1.11; 95% CI 1.07-1.15), and that blood type O individuals were consistently shown gastric cancer risk reduction (OR = 0.91; 95% CI 0.89-0.94). Our study concluded that there was a slightly increased risk of gastric cancer in blood group A individuals, and people with blood type A are more prone to be infected by H. pylori than other ABO blood type individuals, whereas, a slightly decreased risk of gastric cancer was identified in blood type O individuals.

  6. A case/control study of adult haematological malignancies in relation to overhead powerlines.

    PubMed Central

    Youngson, J. H.; Clayden, A. D.; Myers, A.; Cartwright, R. A.

    1991-01-01

    A population based case control study of adult haematological malignancy and distance from, and magnetic fields associated with, overhead (OH) power lines has been carried out in the North West and Yorkshire regions of England. Three-thousand, one hundred and forty-four cases with histologically proven disease were entered into the study. One control per case, matched for age, sex, year of diagnosis and health district of residence, was selected from hospital discharges. Seven per cent of cases and controls lived near to OH power lines as defined by the study protocol. The measure of exposure used was the calculated magnetic field strength at each of these addresses due to maximum load currents carried by OH power lines in the 5 years preceding diagnosis. The odds ratio (OR) for living within 50 m of an OH line was 1.29 with a 95% Confidence Interval (CI) of 0.99-1.68 but a chi 2 test for trend with distance was not statistically significant. The analysis of calculated magnetic fields, did not produce any statistically odds ratios. The OR for magnetic fields greater than or equal to 0.1 mG was 1.03 (95% CI 0.81 1.32). Analysis of magnetic fields greater than or equal to 3.0 mG gave an OR of 1.87 (95% CI 0.79 4.42), but this result is based on small numbers. No evidence was found for confounding by the type of dwelling which was used as a partial surrogate for socio-economic status. PMID:2069855

  7. Handling missing data in matched case-control studies using multiple imputation.

    PubMed

    Seaman, Shaun R; Keogh, Ruth H

    2015-12-01

    Analysis of matched case-control studies is often complicated by missing data on covariates. Analysis can be restricted to individuals with complete data, but this is inefficient and may be biased. Multiple imputation (MI) is an efficient and flexible alternative. We describe two MI approaches. The first uses a model for the data on an individual and includes matching variables; the second uses a model for the data on a whole matched set and avoids the need to model the matching variables. Within each approach, we consider three methods: full-conditional specification (FCS), joint model MI using a normal model, and joint model MI using a latent normal model. We show that FCS MI is asymptotically equivalent to joint model MI using a restricted general location model that is compatible with the conditional logistic regression analysis model. The normal and latent normal imputation models are not compatible with this analysis model. All methods allow for multiple partially-observed covariates, non-monotone missingness, and multiple controls per case. They can be easily applied in standard statistical software and valid variance estimates obtained using Rubin's Rules. We compare the methods in a simulation study. The approach of including the matching variables is most efficient. Within each approach, the FCS MI method generally yields the least-biased odds ratio estimates, but normal or latent normal joint model MI is sometimes more efficient. All methods have good confidence interval coverage. Data on colorectal cancer and fibre intake from the EPIC-Norfolk study are used to illustrate the methods, in particular showing how efficiency is gained relative to just using individuals with complete data.

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

    PubMed Central

    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 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. Results 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 < 0.0001). The adjusted odds ratio (OR) of the risk of glaucoma for those with 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). Conclusions 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. PMID:25720944

  9. A case-control study of dietary salt intake in pediatric-onset multiple sclerosis

    PubMed Central

    McDonald, Jamie; Graves, Jennifer; Waldman, Amy; Lotze, Timothy; Schreiner, Teri; Belman, Anita; Greenberg, Benjamin; Weinstock-Guttman, Bianca; Aaen, Gregory; Tillema, Jan-Mendelt; Hart, Janace; Lulu, Sabeen; Ness, Jayne; Harris, Yolanda; Rubin, Jennifer; Candee, Meghan; Krupp, Lauren B.; Gorman, Mark; Benson, Leslie; Rodriguez, Moses; Chitnis, Tanuja; Mar, Soe; Barcellos, Lisa F.; Laraia, Barbara; Rose, John; Roalstad, Shelly; Simmons, Timothy; Casper, T. Charles; Waubant, Emmanuelle

    2016-01-01

    Background High salt intake may be associated with pro-inflammatory changes in the immune response, and increased clinical and MRI activity in adults with relapsing-remitting multiple sclerosis. Objective We sought to determine if dietary salt intake is associated with pediatric-onset MS risk in a multicenter, case-control study. Methods Pediatric-onset CIS/MS cases within four years of onset and controls less than 22 years old recruited from 14 pediatric-MS centers were studied. Dietary sodium intake was assessed using the validated Block Kids Food Screener (NutritionQuest). Sodium intake, excess sodium, and sodium terciles were compared between cases and controls. Logistic regression models were adjusted for age, gender, ethnicity, body mass index, and socioeconomic status. Results Among 170 cases (mean age=15.2±3.5) and 331 controls (mean age=14.0±3.7), no significant difference in unadjusted mean sodium intake was found between cases (2044 mg/d) and controls (2030 mg/d, p=0.99). The proportion of subjects consuming excess sodium, based on the adequate intake for age and gender, was similar between cases and controls (65% versus 69%, p=0.34). There were no increased odds of higher sodium intake among cases as compared to controls (for each 100 mg/d increase in sodium, OR=1.00, 95% CI 0.98, 1.02; p=0.93, for excess sodium intake, OR=1.05, 95% CI 0.67, 1.64; p=0.84). Conclusions Our results show no strong association between dietary salt intake and pediatric-onset MS risk, suggesting that salt intake may not play a prominent role in susceptibility to MS in children. PMID:27063630

  10. Non-melanoma skin cancer: a case-control study on risk factors and protective measures.

    PubMed

    Suárez-Varela, M M; Llopis Gonzalez, A; Ferrer Caraco, E

    1996-01-01

    There is considerable evidence that exposure to ultraviolet radiation increases the risk of many dermatological conditions, such as non-melanoma skin cancer (NMSC). In order to better understand this relationship, we examined the connection between quantitative measures of individual sun exposure and the risk of NMSC, and the benefits of some protective measures against sunlight, analyzing the differences by sex. A case-control study was conducted in Valencia, Spain during 1990 to 1992 that included 276 cases of histologically confirmed NMSC and 552 control subjects matched by age, sex, and area of residence. Quantitative ultraviolet exposure, phenotypic features, and protective measures from sunlight were estimated by means of a history questionnaire administered by interview. Logistic regression analysis was carried out for each variable and level of quantitative measures. We observed a statistically significant increase in the risk of NMSC proportional to an increase in the hours of occupational exposure to the sun (OR = 1.2, 2.5, and 5.3, respectively). An increased risk of NMSC was observed in men with high nonoccupational exposure (OR = 1.7; p < 0.05 in open-air activities in the sun, OR = 2.1; p < 0.05 in the sun while on vacation). In women, we found instances of OR > 1, but without significance (p > 0.05). Wearing a hat at work appeared to be an important protective measure for men. Light phenotypic features predominated in our study, especially in women, and seems to be the major risk factor involved. It seems reasonable to presume that differences between the sexes are basically sociocultural, (i.e., different work activities and different use of leisure time.

  11. Ultrasound evaluation of intrinsic plantar muscles and fascia in hallux valgus: A case-control study.

    PubMed

    Lobo, César Calvo; Marín, Alejandro Garrido; Sanz, David Rodríguez; López, Daniel López; López, Patricia Palomo; Morales, Carlos Romero; Corbalán, Irene Sanz

    2016-11-01

    A cross-sectional area (CSA) and thickness reduction of the abductor hallucis (AbH) is shown in subjects with hallux valgus (HV). To date, other soft-tissue structures have not been researched in relation with HV. The aim of this study was to compare the CSA and thickness of the intrinsic plantar muscles and fascia (PF) between feet with and without HV. Therefore, a cross-sectional and case-control study was performed using B-mode with an iU22 Philips ultrasound system and a 5 to 17-MHz transducer. The CSA and thickness were measured for the AbH, flexor digitorum brevis (FDB) and flexor hallucis brevis (FHB), and also the thickness for the anterior, middle, and posterior PF portions. A convenience sample of 40 feet, 20 with HV and 20 without HV, was recruited from a clinical and research center. A multivariate regression analysis using linear regression was performed to evaluate the ultrasound imaging measurements (α = 0.05). Consequently, statistically significant differences were observed between the groups (P < 0.05) for the AbH and FHB thickness, and CSA reduction, and also the plantar fascia thickness increase in favor of the HV group. On the contrary, the FDB thickness and CSA did not show statistically significant differences (P ≥ 0.05). In conclusion, the CSA and thickness of the AbH and FHB intrinsic plantar muscles are reduced, whereas the thickness of the anterior, middle, and posterior PF portions are increased, in subjects with HV compared with those without HV.

  12. Selective Immunoglobulin M Deficiency Among Clozapine-Treated Patients: A Nested Case-Control Study

    PubMed Central

    Marin, Reyes; Santacruz, Maria-Jesus; Pascual, Asunción

    2015-01-01

    Objective: To analyze the presence of selective immunoglobulin M immunodeficiency (SIgMD) among long-term clozapine-treated outpatients in a nested case-control study. Method: We investigated 33 patients who took clozapine and found 6 patients with SIgMD. These patients were compared with 67 patients not taking clozapine, of whom 2 had SIgMD. Of these 6 and 2 patients, we made a group of 8 case-patients with SIgMD. This group was compared with 92 (27 + 65) patients without SIgMD matched to cases on age, sex, weight, mental health unit, diagnosis, and psychiatric medication. In both groups there were patients who had taken clozapine: 6 of 8 in the SIgMD group (75%) and 27 of 92 in the non–SIgMD group (29%). SIgMD was defined by mean IgM values ≤ 30 mg/dL. IgM measurements were performed every 6 months, and the data were averaged for each subject. The study was conducted from January 2009 to December 2013. Results: We found a statistical association between clozapine use and the presence of SIgMD (OR = 7.2222; 95% CI, 1.3704–38.0623; Z = 2.332; P = .0197). Conclusions: Due to the high incidence of SIgMD observed in schizophrenic patients treated with clozapine, clinicians should pay particular attention to not only granulocyte counts but also patterns of IgM decline to prevent drug iatrogenesis. PMID:26693046

  13. Suspected collagen disorders in the bleeding disorder clinic: a case-control study.

    PubMed

    Jackson, S C; Odiaman, L; Card, R T; van der Bom, J G; Poon, M-C

    2013-03-01

    Disorders of collagen are associated with a mild bleeding tendency because of the potential abnormal interaction of collagen, von Willebrand factor (VWF) and platelets required during primary haemostasis and due to generalized soft tissue fragility. Abnormal collagen may contribute to bleeding in existing mucocutaneous bleeding disorders, but the prevalence in this setting is unknown. Generalized symptomatic joint hypermobility (SJH) is common in collagen disorders and may be objectively measured. To assess the association between symptomatic joint hypermobility and mucocutaneous bleeding disorders, we performed a case-control study in which case subjects were 55 consecutive individuals who had visited our bleeding disorder clinic with a diagnosis of von Willebrand disease, low von Willebrand factor levels, mild platelet function disorder or undefined bleeding disorder. Controls were 50 subjects without a bleeding disorder, and were age and gender matched to the cases. All subjects were assessed with: (i) Beighton score for joint hypermobility, (ii) revised Brighton criteria, (iii) Condensed MCMDM1-VWD bleeding questionnaire, and (iv) haemostasis laboratory studies. The prevalence of SJH/suspected collagen disorder in the bleeding disorder clinic was 24% (13/55) compared with 2% (1/50) in the control population (OR 15, 95% CI 2-121). Seventy-seven per cent of bleeding disorder clinic SJH subjects (10/13) had a prior personal or family history of Ehlers-Danlos, Benign Joint Hypermobility Syndrome or Osteogenesis Imperfecta (OI). Symptomatic joint hypermobility was associated with increased odds of an underlying mucocutaneous bleeding disorder. These findings suggest that a collagen disorder is common and often unrecognized in the bleeding disorder clinic as a potential contributor to the bleeding symptoms.

  14. Diet Quality Scores and Risk of Nasopharyngeal Carcinoma in Chinese Adults: A Case-Control Study

    PubMed Central

    Wang, Cheng; Lin, Xiao-Ling; Fan, Yu-Ying; Liu, Yuan-Ting; Zhang, Xing-Lan; Lu, Yun-Kai; Xu, Chun-Hua; Chen, Yu-Ming

    2016-01-01

    Many studies show that dietary factors may affect the risk of nasopharyngeal carcinoma (NPC). We examined the association between overall diet quality and NPC risk in a Chinese population. This case-control study included 600 NPC patients and 600 matched controls between 2009 and 2011 in Guangzhou, China. Habitual dietary intake and various covariates were assessed via face-to-face interviews. Diet quality scores were calculated according to the Healthy Eating Index-2005 (HEI-2005), the alternate Healthy Eating Index (aHEI), the Diet Quality Index-International (DQI-I), and the alternate Mediterranean Diet Score (aMed). After adjustment for various lifestyle and dietary factors, greater diet quality scores on the HEI-2005, aHEI, and DQI-I—but not on the aMed—showed a significant association with a lower risk of NPC (p-trends, <0.001–0.001). The odds ratios (95% confidence interval) comparing the extreme quartiles of the three significant scores were 0.47 (0.32–0.68) (HEI-2005), 0.48 (0.33–0.70) (aHEI), and 0.43 (0.30–0.62) (DQI-I). In gender-stratified analyses, the favorable association remained significant in men but not in women. We found that adherence to the predefined dietary patterns represented by the HEI-2005, aHEI, and DQI-I scales predicted a lower risk of NPC in adults from south China, especially in men. PMID:26927167

  15. The health watch case-control study of leukemia and benzene: the story so far.

    PubMed

    Glass, Deborah C; Gray, Christopher N; Jolley, Damien J; Gibbons, Carl; Sim, Malcolm R

    2006-09-01

    A case-control study nested in the Health Watch cohort of petroleum industry workers, investigated whether the excess of lymphohematopoetic cancers, identified among male members of the Health Watch cohort, was associated with benzene exposure. Cases of non-Hodgkin's lymphoma (n = 31), multiple myeloma (n = 15), and leukemia (n = 33) were identified between 1981 and 1999. Cases were age-matched to five controls. Exposure was retrospectively estimated for each occupational history using an algorithm in a relational database. Benzene exposure measurements, supplied by Australian petroleum companies, were used to estimate exposure for specific tasks. The tasks carried out within the job, the products handled, and the technology used, were identified from interviews with contemporary colleagues. More than half of the subjects started work after 1965 and had an average exposure period of 20 years. Exposure was low, 85% of the cumulative exposure estimates were <10 ppm years. Matched analyses showed that non-Hodgkin's lymphoma and multiple myeloma were not associated with benzene exposure. Leukemia risk, however, was significantly increased for the subjects with greater than 16 ppm years cumulative exposure, odds ratio (OR) 51.9 (5.6-477) or with greater than 0.8 ppm intensity of highest exposed job. Cumulative exposures were similar to those found in comparable studies. The inclusion of occasional high exposures, for example, as a result of spillages, reduced the ORs, when the exposure was treated as either a continuous or a categorical variable. Our data demonstrate a strong association between leukemia and modest benzene exposure. The choice of cut-point and reference group has a marked effect on the ORs, but does not change the overall conclusions.

  16. A case-control study of risk factors for brucellosis seropositivity in Portuguese small ruminants herds.

    PubMed

    Coelho, A M; Coelho, A C; Roboredo, M; Rodrigues, J

    2007-12-14

    A case-control study involving 255 small ruminants herds randomly selected was carried out in Portugal between January and December 2004, to identify risk factors associated with brucellosis seropositivity. To achieve this objective, two groups of herds selected according their prevalence status were compared: "cases" (farms with seroprevalence higher than 5%, n=123) and "controls" (farms seronegatives, n=132). A carefully structured questionnaire was used to collect data from each herd. A statistical analysis to compare "case" versus "control" herds was performed with the variables obtained from the questionnaire and the seroprevalence results. The effects on seroprevalence of several variables such as: individual characteristics; farm management practices; farm characteristics; animal health; knowledge and characteristics of farmers were evaluated. Data were analysed using logistic regression. Univariable analysis was used to screen the variables used in the logistic regression model. Nine variables were associated with brucellosis seropositivity in univariable analysis p<0.10. These variables were retained for multivariable logistic regression model. Regression model identified five variables as risk factors for seropositivity. The odds of brucellosis were increased: herds with more than 116 animals (OR=2.99); in herds with no cleaned-watering places (OR=3.05); in herds with insufficient manure removal and insufficient cleaning of premises (OR=2.87); in introduction of animals from non-free brucellosis herds or from herds of unknown status (OR=12.11). In the other hand, farmers' age (the eldest) was related to decreased odds (OR=0.4). Potential risk factors identified in this study were consistent factors associated with brucellosis seropositivity and support current recommendations for the control of brucellosis. Considering the paucity of epidemiological reports on brucellosis in the Northeast of Portugal and the absence of any data concerning factors related

  17. Vitamin D–binding protein and pancreatic cancer: a nested case-control study12345

    PubMed Central

    Piper, Marina R; Freedman, D Michal; Robien, Kim; Kopp, William; Rager, Helen; Horst, Ronald L

    2015-01-01

    Background: Vitamin D–binding protein (DBP) is the primary carrier of 25-hydroxyvitamin D [25(OH)D] in the circulation. One prospective study in male smokers found a protective association between DBP and pancreatic cancer, particularly among men with higher 25(OH)D concentrations. Objective: The objective was to examine the association between DBP and pancreatic cancer risk in an American population. Design: We conducted a nested case-control study in the Prostate, Lung, Colorectal, and Ovarian Cancer screening trial cohort of men and women aged 55–74 y at baseline. Between 1993 and 2010, 295 incident pancreatic adenocarcinoma cases were reported (follow-up to 15.1 y). Two controls (n = 590) were matched to each case by age, race, sex, and month of blood draw. We calculated smoking- and diabetes-adjusted ORs and 95% CIs with the use of conditional logistic regression. Results: DBP concentration was not significantly associated with pancreatic cancer overall [highest (≥7149.4 nmol/L) vs. lowest (<3670.4 nmol/L) quintile; OR: 1.75; 95% CI: 0.91, 3.37; P-trend = 0.25]. For serum 25(OH)D compared with the referent (50 to <75 nmol/L), individuals in the highest group had a significantly higher risk (≥100 nmol/L; OR: 3.23; 95% CI: 1.24, 8.44), whereas those in the lowest group had no significant association (<25 nmol/L; OR: 2.50; 95% CI: 0.92, 6.81). Further adjustment for DBP did not alter this association. Conclusion: Our results do not support the hypothesis that serum DBP or 25(OH)D plays a protective role in pancreatic cancer. This trial was registered at clinicaltrials.gov as NCT00339495. PMID:25904602

  18. Association of hypothyroidism with unruptured cerebral aneurysms: a case-control study.

    PubMed

    Atchaneeyasakul, Kunakorn; Tipirneni, Anita; Zhang, Tony; Khandelwal, Priyank; Ambekar, Sudheer; Snelling, Brian; Dharmadhikari, Sushrut; Dong, Chuanhui; Guada, Luis; Ramdas, Kevin; Chaturvedi, Seemant; Rundek, Tatjana; Yavagal, Dileep R

    2017-02-17

    OBJECTIVE Thyroid disorder has been known to affect vascular function and has been associated with aortic aneurysm formation in some cases; however, the connection has not been well studied. The authors hypothesized that hypothyroidism is associated with the formation of cerebral aneurysms. METHODS The authors performed a retrospective case-control study of consecutive patients who had undergone cerebral angiography at an academic, tertiary care medical center in the period from April 2004 through April 2014. Patients with unruptured aneurysms were identified from among those who had undergone 3-vessel catheter angiography. Age-matched controls without cerebral aneurysms on angiography were also identified from the same database. Patients with previous subarachnoid hemorrhage or intracranial hemorrhage were excluded. History of hypothyroidism and other risk factors were recorded. RESULTS Two hundred forty-three patients with unruptured cerebral aneurysms were identified and age matched with 243 controls. Mean aneurysm size was 9.6 ± 0.8 mm. Hypothyroidism was present in 40 patients (16.5%) and 9 matched controls (3.7%; adjusted OR 3.2, 95% CI 1.3-7.8, p = 0.01). Subgroup analysis showed that men with hypothyroidism had higher odds of an unruptured cerebral aneurysm diagnosis than the women with hypothyroidism, with an adjusted OR of 12.7 (95% CI 1.3-121.9) versus an OR of 2.5 (95% CI 1.0-6.4) on multivariate analysis. CONCLUSIONS Hypothyroidism appears to be independently associated with unruptured cerebral aneurysms, with a higher effect seen in men. Given the known pathophysiological associations between hypothyroidism and vascular dysfunction, this finding warrants further exploration.

  19. An Exploratory Case Control Study of Risk Factors for Hepatitis E in Rural Bangladesh

    PubMed Central

    Labrique, Alain B.; Zaman, K.; Hossain, Zahid; Saha, Parimalendu; Yunus, Mohammad; Hossain, Anowar; Ticehurst, John; Kmush, Brittany; Nelson, Kenrad E.

    2013-01-01

    Hepatitis E virus (HEV) is the major cause of epidemic and sporadic hepatitis globally. Outbreaks are associated with fecal contamination of drinking water, yet the environmental reservoir of HEV between epidemics remains unclear. In contrast to neighboring countries, where epidemics and sporadic disease co-occur, HEV-endemic communities in rural Bangladesh seldom report outbreaks; sporadic hepatitis E is reported from urban and rural areas of the country. Besides typical enteric risk factors, other routes for HEV infection and disease are unclear. We conducted monthly household surveillance of a southern Bangladeshi community of 23,500 people to find incident cases of acute hepatitis E over a 22 month period. An algorithm was used to capture 279 candidate cases, of which 46 were confirmed acute HEV infections. An exploratory case-control study was conducted to identify putative risk factors for disease. Nearly 70% of cases were over 15 years old. Female gender seemed protective (OR:0.34) against hepatitis E in this conservative setting, as was the use of sanitary latrines (OR:0.28). Socioeconomic status or animal exposures were not significant predictors of disease, although outdoor employment and recent urban travel were. Unexpectedly, recent contact with a “jaundiced” patient and a history of injection exposure in the 3 months prior to disease (OR:15.50) were significant. Susceptible individuals from “endemic” communities share similar enteric exposure risks to those commonly associated with tourists from non-endemic countries. This study also raises the novel possibility of parenteral and person-to-person transmission of HEV in non-epidemic, sporadic disease settings. PMID:23675410

  20. Predictors of Default from Treatment for Tuberculosis: a Single Center Case-Control Study in Korea.

    PubMed

    Park, Cheol-Kyu; Shin, Hong-Joon; Kim, Yu-Il; Lim, Sung-Chul; Yoon, Jeong-Sun; Kim, Young-Su; Kim, Jung-Chul; Kwon, Yong-Soo

    2016-02-01

    Default from tuberculosis (TB) treatment could exacerbate the disease and result in the emergence of drug resistance. This study identified the risk factors for default from TB treatment in Korea. This single-center case-control study analyzed 46 default cases and 100 controls. Default was defined as interrupting treatment for 2 or more consecutive months. The reasons for default were mainly incorrect perception or information about TB (41.3%) and experience of adverse events due to TB drugs (41.3%). In univariate analysis, low income (< 2,000 US dollars/month, 88.1% vs. 68.4%, P = 0.015), absence of TB stigma (4.3% vs. 61.3%, P < 0.001), treatment by a non-pulmonologist (74.1% vs. 25.9%, P < 0.001), history of previous treatment (37.0% vs. 19.0%, P = 0.019), former defaulter (15.2% vs. 2.0%, P = 0.005), and combined extrapulmonary TB (54.3% vs. 34.0%, P = 0.020) were significant risk factors for default. In multivariate analysis, the absence of TB stigma (adjusted odd ratio [aOR]: 46.299, 95% confidence interval [CI]: 8.078-265.365, P < 0.001), treatment by a non-pulmonologist (aOR: 14.567, 95% CI: 3.260-65.089, P < 0.001), former defaulters (aOR: 33.226, 95% CI: 2.658-415.309, P = 0.007), and low income (aOR: 5.246, 95% CI: 1.249-22.029, P = 0.024) were independent predictors of default from TB treatment. In conclusion, patients with absence of disease stigma, treated by a non-pulmonologist, who were former defaulters, and with low income should be carefully monitored during TB treatment in Korea to avoid treatment default.

  1. Apolipoprotein E genetic polymorphism, serum lipoprotein levels and breast cancer risk: A case-control study

    PubMed Central

    CIBEIRA, GABRIELA HERRMANN; GIACOMAZZI, JULIANA; AGUIAR, ERNESTINA; SCHNEIDER, SILVANA; ETTRICH, BETINA; DE SOUZA, CAROLINE ISOPPO; CAMEY, SUZI; CALEFFI, MAIRA; WEBER, BERNARDETE; ASHTON-PROLLA, PATRICIA; MORIGUCHI, EMILIO HIDEYUKI

    2014-01-01

    The purpose of this study was to evaluate the association between apolipoprotein E (APOE) allelic frequency, serum lipoproteins and breast cancer (BC). We conducted a nested case-control study within a cohort including 47 cases and 165 controls. Polymerase chain reaction-restriction fragment length polymorphism analyses of the APOE polymorphism were performed. In general, participants with the genotype including alleles e2 and e3 tended to have lower serum triglycerides, total cholesterol and low-density lipoprotein cholesterol levels and higher high-density lipoprotein (HDL) cholesterol levels compared to participants homozygous for the e3 allele and participants heterozygous for the e3 and e4 alleles, respectively. BC patients exhibited higher mean levels of total serum cholesterol (P=0.070), dietary fat intake (P=0.020) and dietary cholesterol intake (P=0.017) compared to control subjects. The allelic distribution between the two groups revealed that the presence of the e2 allele was positively associated with the absence of BC, whereas the e4 allele was positively associated with the BC case group (P=0.019). The distribution of the APOE genotypes was not significantly different between cases and controls (P=0.172). The concomitant presence of the e2 and e4 alleles was positively associated with the absence of BC and e4/e4 homozygosity was positively associated with BC (P=0.021). Our findings suggested that APOE polymorphism plays an important role in the development of BC, particularly when associated with higher serum triglyceride levels. PMID:25279190

  2. Antipsychotic Medications and Risk of Acute Coronary Syndrome in Schizophrenia: A Nested Case-Control Study

    PubMed Central

    Liu, Hsing-Cheng; Yang, Shu-Yu; Liao, Ya-Tang; Chen, Chiao-Chicy; Kuo, Chian-Jue

    2016-01-01

    Background This study assessed the risk of developing acute coronary syndrome requiring hospitalization in association with the use of certain antipsychotic medications in schizophrenia patients. Methods A nationwide cohort of 31,177 inpatients with schizophrenia between the ages of 18 and 65 years whose records were enrolled in the National Health Insurance Research Database in Taiwan from 2000 to 2008 and were studied after encrypting the identifications. Cases (n = 147) were patients with subsequent acute coronary syndrome requiring hospitalization after their first psychiatric admission. Based on a nested case-control design, each case was matched with 20 controls for age, sex and the year of first psychiatric admission using risk-set sampling. The effects of antipsychotic agents on the development of acute coronary syndrome were assessed using multiple conditional logistic regression and sensitivity analyses to confirm any association. Results We found that current use of aripiprazole (adjusted risk ratio [RR] = 3.68, 95% CI: 1.27–10.64, p<0.05) and chlorpromazine (adjusted RR = 2.96, 95% CI: 1.40–6.24, p<0.001) were associated with a dose-dependent increase in the risk of developing acute coronary syndrome. Although haloperidol was associated with an increased risk (adjusted RR = 2.03, 95% CI: 1.20–3.44, p<0.01), there was no clear dose-dependent relationship. These three antipsychotic agents were also associated with an increased risk in the first 30 days of use, and the risk decreased as the duration of therapy increased. Sensitivity analyses using propensity score-adjusted modeling showed that the results were similar to those of multiple regression analysis. Conclusions Patients with schizophrenia who received aripiprazole, chlorpromazine, or haloperidol could have a potentially elevated risk of developing acute coronary syndrome, particularly at the start of therapy. PMID:27657540

  3. Diarrhea Etiology in a Pediatric Emergency Department: A Case Control Study

    PubMed Central

    Denno, Donna M.; Shaikh, Nurmohammad; Stapp, Jenny R.; Qin, Xuan; Hutter, Carolyn M.; Hoffman, Valerie; Mooney, Jody C.; Wood, Kelly M.; Stevens, Harold J.; Jones, Robert; Tarr, Phillip I.; Klein, Eileen J.

    2012-01-01

    Background. The etiology of childhood diarrhea is frequently unknown. Methods. We sought Aeromonas, Campylobacter, Escherichia coli O157:H7, Pleisiomonas shigelloides, Salmonella, Shigella, Vibrio, and Yersinia (by culture), adenoviruses, astroviruses, noroviruses, rotavirus, and Shiga toxin-producing E. coli (STEC; by enzyme immunoassay), Clostridium difficile (by cytotoxicity), parasites (by microscopy), and enteroaggregative E. coli (EAEC; by polymerase chain reaction [PCR] analysis) in the stools of 254 children with diarrhea presenting to a pediatric emergency facility. Age- and geographic-matched community controls without diarrhea (n = 452) were similarly studied, except bacterial cultures of the stool were limited only to cases. Results. Twenty-nine (11.4%) case stools contained 13 Salmonella, 10 STEC (6 O157:H7 and 4 non-O157:H7 serotypes), 5 Campylobacter, and 2 Shigella. PCR-defined EAEC were present more often in case (3.2%) specimens than in control (0.9%) specimens (adjusted odds ratio [OR], 3.9; 95% confidence interval [CI], 1.1–13.7), and their adherence phenotypes were variable. Rotavirus, astrovirus, and adenovirus were more common among cases than controls, but both groups contained noroviruses and C. difficile at similar rates. PCR evidence of hypervirulent C. difficile was found in case and control stools; parasites were much more common in control specimens. Conclusions. EAEC are associated with childhood diarrhea in Seattle, but the optimal way to identify these agents warrants determination. Children without diarrhea harbor diarrheagenic pathogens, including hypervirulent C. difficile. Our data support the importance of taking into account host susceptibility, microbial density, and organism virulence traits in future case-control studies, not merely categorizing candidate pathogens as being present or absent. PMID:22700832

  4. Metabolic markers or conditions preceding Parkinson's disease: a case-control study.

    PubMed

    Savica, Rodolfo; Grossardt, Brandon R; Ahlskog, J Eric; Rocca, Walter A

    2012-07-01

    Several metabolic markers or conditions have been explored as possible risk or protective factors for Parkinson's disease (PD); however, results remain conflicting. We further investigated these associations using a case-control study design. We used the medical records-linkage system of the Rochester Epidemiology Project to identify 196 subjects who developed PD in Olmsted County, Minnesota, 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 abstract information about body mass index (BMI), cholesterol level, hypertension, and diabetes mellitus preceding the onset of PD (or the index year). There were no significant differences between cases and controls for the metabolic markers or conditions investigated. No significant associations were found using 2 cutoffs for BMI level (BMI ≥ 25 or BMI ≥ 30 kg/m(2) ) and 3 cutoffs for cholesterol levels (>200, >250, or >300 mg/dL). Neither a diagnosis of hypertension or the documented use of antihypertensive medications was significantly associated with the subsequent risk of PD (odds ratio [OR], 1.00; 95% confidence interval [CI], 0.65-1.54; P = .99) nor was a diagnosis of diabetes mellitus or the use of glucose-lowering medications (OR, 0.77; 95% CI, 0.37-1.57; P = .47). Our study, based on historical information from a records-linkage system, does not support an association between BMI, cholesterol level, hypertension, or diabetes mellitus with later development of PD.

  5. The effect of opium dependency on testis volume: a case-control study

    PubMed Central

    Cyrus, Ali; Solhi, Hassan; Azizabadi Farahani, Mahdi; Khoddami Vishteh, Hamid Reza; Goudarzi, Davoud; Mosayebi, Ghasem; Mohamadian, Hamed

    2012-01-01

    Background: Given the paucity of data on possible testis changes in opioid dependents, we sought to compare the testis volumes between a group of opium dependents and a group of healthy controls. Objective: Comparison of testis volume between opium dependents and healthy controls. Materials and Methods: This case-control study recruited 100 men with opium dependency (cases) and 100 healthy men (controls) in Iran, in 2008. A checklist containing questions about age, height, weight, daily amount of cigarette use, and duration of cigarette use for all the participants as well as daily amount of opium use (grams) and duration of opium use (years) for the case group was completed. Additionally, the dimensions of each testis were measured by a single person using calipers, and the mean of the left and right testes volume was compared between these two groups. Results: The mean of the testis volumes in the case group was significantly lower than that of the case group (11.2±2.2 and 25.1±2.7cm³, p<0.001). The results of the ANCOVA test showed that even after the omission of the cigarette smoking effect (p=0.454), the testis volume remained lower in the opium dependents (R2=0.884, p<0.001). In the case group, there were significant reverse correlations between testis volume and age (r=-0.404, p<0.001), daily amount of opium use (r=-0/207, p=0.039) and duration of opium use (r=-0.421, p<0.001). Conclusion: We found that the testis volume in the male opium dependents was lower than that of the healthy controls. We would recommend that future studies into the impact of drugs on the testis dimensions pay heed to possible histological changes in the testes owing to opium dependency. PMID:25246920

  6. Factors associated with excessive bleeding in cardiopulmonary bypass patients: a nested case-control study

    PubMed Central

    Jimenez Rivera, Juan J; Iribarren, Jose L; Raya, Jose M; Nassar, Ibrahim; Lorente, Leonardo; Perez, Rosalia; Brouard, Maitane; Lorenzo, Jose M; Garrido, Pilar; Barrios, Ysamar; Diaz, Maribel; Alarco, Blas; Martinez, Rafael; Mora, Maria L

    2007-01-01

    Introduction Excessive bleeding (EB) after cardiopulmonary bypass (CPB) may lead to increased mortality, morbidity, transfusion requirements and re-intervention. Less than 50% of patients undergoing re-intervention exhibit surgical sources of bleeding. We studied clinical and genetic factors associated with EB. Methods We performed a nested case-control study of 26 patients who did not receive antifibrinolytic prophylaxis. Variables were collected preoperatively, at intensive care unit (ICU) admission, at 4 and 24 hours post-CPB. EB was defined as 24-hour blood loss of >1 l post-CPB. Associations of EB with genetic, demographic, and clinical factors were analyzed, using SPSS-12.2 for statistical purposes. Results EB incidence was 50%, associated with body mass index (BMI)< 26.4 (25–28) Kg/m2, (P = 0.03), lower preoperative levels of plasminogen activator inhibitor-1 (PAI-1) (P = 0.01), lower body temperature during CPB (P = 0.037) and at ICU admission (P = 0.029), and internal mammary artery graft (P = 0.03) in bypass surgery. We found a significant association between EB and 5G homozygotes for PAI-1, after adjusting for BMI (F = 6.07; P = 0.02) and temperature during CPB (F = 8.84; P = 0.007). EB patients showed higher consumption of complement, coagulation, fibrinolysis and hemoderivatives, with significantly lower leptin levels at all postoperative time points (P = 0.01, P < 0.01 and P < 0.01). Conclusion Excessive postoperative bleeding in CPB patients was associated with demographics, particularly less pronounced BMI, and surgical factors together with serine protease activation. PMID:17425777

  7. Biomarkers and Bacterial Pneumonia Risk in Patients with Treated HIV Infection: A Case-Control Study

    PubMed Central

    Bjerk, Sonja M.; Baker, Jason V.; Emery, Sean; Neuhaus, Jacqueline; Angus, Brian; Gordin, Fred M.; Pett, Sarah L.; Stephan, Christoph; Kunisaki, Ken M.

    2013-01-01

    Background Despite advances in HIV treatment, bacterial pneumonia continues to cause considerable morbidity and mortality in patients with HIV infection. Studies of biomarker associations with bacterial pneumonia risk in treated HIV-infected patients do not currently exist. Methods We performed a nested, matched, case-control study among participants randomized to continuous combination antiretroviral therapy (cART) in the Strategies for Management of Antiretroviral Therapy trial. Patients who developed bacterial pneumonia (cases) and patients without bacterial pneumonia (controls) were matched 1∶1 on clinical center, smoking status, age, and baseline cART use. Baseline levels of Club Cell Secretory Protein 16 (CC16), Surfactant Protein D (SP-D), C-reactive protein (hsCRP), interleukin-6 (IL-6), and d-dimer were compared between cases and controls. Results Cases (n = 72) and controls (n = 72) were 25.7% female, 51.4% black, 65.3% current smokers, 9.7% diabetic, 36.1% co-infected with Hepatitis B/C, and 75.0% were on cART at baseline. Median (IQR) age was 45 (41, 51) years with CD4+ count of 553 (436, 690) cells/mm3. Baseline CC16 and SP-D were similar between cases and controls, but hsCRP was significantly higher in cases than controls (2.94 µg/mL in cases vs. 1.93 µg/mL in controls; p = 0.02). IL-6 and d-dimer levels were also higher in cases compared to controls, though differences were not statistically significant (p-value 0.06 and 0.10, respectively). Conclusions In patients with cART-treated HIV infection, higher levels of systemic inflammatory markers were associated with increased bacterial pneumonia risk, while two pulmonary-specific inflammatory biomarkers, CC16 and SP-D, were not associated with bacterial pneumonia risk. PMID:23457535

  8. Diet and alcohol as risk factors for rheumatoid arthritis: a nested case-control study.

    PubMed

    Sundström, B; Johansson, I; Rantapää-Dahlqvist, S

    2015-03-01

    The aim of this study was to investigate whether alcohol and diet, assessed as both macronutrients and dietary patterns, increased the risk of development of rheumatoid arthritis (RA) through a nested case-control design in the Västerbotten Intervention Program (VIP) cohort. Individuals in the VIP who had developed RA after the dietary survey were identified from medical records at the department of rheumatology at the University Hospital, Umeå (n = 386), and matched to 1,886 controls from the same database. Diet was assessed as food groups, as macronutrients and as scores of dietary patterns, namely the carbohydrate-restricted diet score, the Mediterranean diet score and the healthy diet indicator score. When analysing the dietary patterns, consumption of food groups and different macronutrients, a significant association was found in the highest tertile of carbohydrate-restricted diet among the cases with a subsequent anti-CCP-positive disease 1.40 (1.02-1.92), as well as in the highest tertile of protein consumption among smokers (OR = 1.80, 95% CI 1.09-2.95). However, after additional adjustment for sodium intake, these associations were no longer statistically significant. No association was observed between alcohol consumption and the risk of RA. To summarize, there were no significant associations between diet, or alcohol consumption, and the risk of development of RA within this cohort. The lack of any significant associations of alcohol consumption may be explained by a low consumption in the studied population overall or alternatively by methodological issues raised recently.

  9. Case-control study of colon cancer and drinking water trihalomethanes in Wisconsin.

    PubMed

    Young, T B; Wolf, D A; Kanarek, M S

    1987-06-01

    A case-control study was conducted to test the hypothesis that chronic ingestion of trihalomethanes (THMs), occurring as chlorination byproducts in drinking water, carries a risk of colon cancer. Lifetime residential and water source histories and information on water-drinking habits, diet, sociodemographics, medical and occupation histories, lifestyle and other factors were obtained by questionnaire from a statewide sample of newly-diagnosed colon cancer cases (N = 347), controls with cancer of other sites (N = 639) and general population controls (N = 611). Since no data on past THM levels exists, it was necessary to devise a scheme to generate THM estimates for all Wisconsin water sources. For this, a statistical model based on quantitative THM measures and routinely-recorded data taken at 81 municipal water facilities was used in conjunction with individual residential histories to estimate lifetime and period-specific THM exposure for each case and control. Logistic regression was used to estimate odds ratios adjusted for age, sex and urban living, for colon cancer and THM exposure. The study results indicate that THM in Wisconsin drinking water does not pose a significant colon cancer risk. Odds ratios for exposure to the middle and highest category of lifetime cumulative THM were 1.05 (95% Cl = 0.66-1.68) and 0.93(95%Cl = 0.55-1.57) respectively, relative to the cancer control group, and 1.10 (95%Cl = 0.68-1.78) and 0.73 (95% Cl = 0.44-1.21) respectively, relative to the general population controls.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Body Mass Index, Smoking and Hypertensive Disorders during Pregnancy: A Population Based Case-Control Study.

    PubMed

    Gudnadóttir, Thuridur A; Bateman, Brian T; Hernádez-Díaz, Sonia; Luque-Fernandez, Miguel Angel; Valdimarsdottir, Unnur; Zoega, Helga

    2016-01-01

    While obesity is an indicated risk factor for hypertensive disorders of pregnancy, smoking during pregnancy has been shown to be inversely associated with the development of preeclampsia and gestational hypertension. The purpose of this study was to investigate the combined effects of high body mass index and smoking on hypertensive disorders during pregnancy. This was a case-control study based on national registers, nested within all pregnancies in Iceland 1989-2004, resulting in birth at the Landspitali University Hospital. Cases (n = 500) were matched 1:2 with women without a hypertensive diagnosis who gave birth in the same year. Body mass index (kg/m2) was based on height and weight at 10-15 weeks of pregnancy. We used logistic regression models to calculate odds ratios and corresponding 95% confidence intervals as measures of association, adjusting for potential confounders and tested for additive and multiplicative interactions of body mass index and smoking. Women's body mass index during early pregnancy was positively associated with each hypertensive outcome. Compared with normal weight women, the multivariable adjusted odds ratio for any hypertensive disorder was 1.8 (95% confidence interval, 1.3-2.3) for overweight women and 3.1 (95% confidence interval, 2.2-4.3) for obese women. The odds ratio for any hypertensive disorder with obesity was 3.9 (95% confidence interval 1.8-8.6) among smokers and 3.0 (95% confidence interval 2.1-4.3) among non-smokers. The effect estimates for hypertensive disorders with high body mass index appeared more pronounced among smokers than non-smokers, although the observed difference was not statistically significant. Our findings may help elucidate the complicated interplay of these lifestyle-related factors with the hypertensive disorders during pregnancy.

  11. Sleep quality and the risk of work injury: a Swiss case-control study.

    PubMed

    Uehli, Katrin; Miedinger, David; Bingisser, Roland; Dürr, Selina; Holsboer-Trachsler, Edith; Maier, Sabrina; Mehta, Amar J; Müller, Roland; Schindler, Christian; Zogg, Stefanie; Künzli, Nino; Leuppi, Jörg D

    2014-10-01

    Sleep problems are a well-known risk factor for work injuries, but less is known about which vulnerable populations are most at risk. The aims of this study were to investigate the association between sleep quality and the risk of work injury and to identify factors that may modify the association. A case-control study including 180 cases and 551 controls was conducted at the University Hospital in Basel, Switzerland, from 1 December 2009 to 30 June 2011. Data on work injuries and sleep quality were collected. Adjusted odds ratios and 95% confidence intervals of the association between sleep quality and work injury were estimated in multivariable logistic regression analyses and were stratified by hypothesized effect modifiers (age, gender, job risk, shift work, sleep duration and working hours). Poor sleep quality was associated significantly with work injury of any type (P < 0.05) and with being caught in particular (P < 0.05). The association between poor sleep quality and work injury was significantly higher for workers older than 30 years (odds ratio>30 1.30 versus odds ratio≤30 0.91, P < 0.01), sleeping 7 h or less per night (odds ratio≤7 1.17 versus odds ratio>7 0.79, P < 0.05) and working 50 h or more per week (odds ratio≥50 1.79 versus odd ratio<50 1.10, P < 0.01). Work injury risk increased with increasing severity of sleep problems (P < 0.05). Prior work injury frequency increased with decreasing sleep quality (P < 0.05). Older age, short sleep duration and long working hours may enhance the risk of work injuries associated with sleep quality.

  12. Parenchymal texture measures weighted by breast anatomy: preliminary optimization in a case-control study

    NASA Astrophysics Data System (ADS)

    Gastounioti, Aimilia; Keller, Brad M.; Hsieh, Meng-Kang; Conant, Emily F.; Kontos, Despina

    2016-03-01

    Growing evidence suggests that quantitative descriptors of the parenchymal texture patterns hold a valuable role in assessing an individual woman's risk for breast cancer. In this work, we assess the hypothesis that breast cancer risk factors are not uniformly expressed in the breast parenchymal tissue and, therefore, breast-anatomy-weighted parenchymal texture descriptors, where different breasts ROIs have non uniform contributions, may enhance breast cancer risk assessment. To this end, we introduce an automated breast-anatomy-driven methodology which generates a breast atlas, which is then used to produce a weight map that reinforces the contributions of the central and upper-outer breast areas. We incorporate this methodology to our previously validated lattice-based strategy for parenchymal texture analysis. In the framework of a pilot case-control study, including digital mammograms from 424 women, our proposed breast-anatomy-weighted texture descriptors are optimized and evaluated against non weighted texture features, using regression analysis with leave-one-out cross validation. The classification performance is assessed in terms of the area under the curve (AUC) of the receiver operating characteristic. The collective discriminatory capacity of the weighted texture features was maximized (AUC=0.87) when the central breast area was considered more important than the upperouter area, with significant performance improvement (DeLong's test, p-value<0.05) against the non-weighted texture features (AUC=0.82). Our results suggest that breast-anatomy-driven methodologies have the potential to further upgrade the promising role of parenchymal texture analysis in breast cancer risk assessment and may serve as a reference in the design of future studies towards image-driven personalized recommendations regarding women's cancer risk evaluation.

  13. Case-control study of childhood cancer and exposure to 60-Hz magnetic fields

    SciTech Connect

    Savitz, D.A.; Wachtel, H.; Barnes, F.A.; John, E.M.; Tvrdik, J.G.

    1988-07-01

    Concern with health effects of extremely low frequency magnetic fields has been raised by epidemiologic studies of childhood cancer in relation to proximity to electric power distribution lines. This case-control study was designed to assess the relation between residential exposure to magnetic fields and the development of childhood cancer. Eligible cases consisted of all 356 residents of the five-county 1970 Denver, Colorado Standard Metropolitan Statistical Area aged 0-14 years who were diagnosed with any form of cancer between 1976 and 1983. Controls were selected by random digit dialing to approximate the case distribution by age, sex, and telephone exchange area. Exposure was characterized through in-home electric and magnetic field measurements under low and high power use conditions and wire configuration codes, a surrogate measure of long-term magnetic field levels. Measured magnetic fields under low power use conditions had a modest association with cancer incidence; a cutoff score of 2.0 milligauss resulted in an odds ratio of 1.4 (95% confidence interval (CI) = 0.6-2.9) for total cancers and somewhat larger odds ratios (ORs) for leukemias (OR = 1.9), lymphomas (OR = 2.2), and soft tissue sarcomas (OR = 3.3). Neither magnetic fields (OR = 1.0) nor electric fields (OR = 0.9) under high power use conditions were related to total cancers. Wire codes associated with higher magnetic fields were more common among case than control homes. The odds ratio to contrast very high and high to very low, low, and buried wire codes was 1.5 (95% CI = 1.0-2.3) for total cases, with consistency across cancer subgroups except for brain cancer (OR = 2.0) and lymphomas (OR = 0.8). Contrasts of very high to buried wire code homes produced larger, less precise odds ratios of 2.3 for total cases, 2.9 for leukemias, and 3.3 for lymphomas.

  14. Association of endotoxins and colon polyp: a case-control study.

    PubMed

    Lee, Kang-Kon; Yum, Keun-Sang

    2012-09-01

    Endotoxins are known to be associated with the occurrence of various chronic diseases. This study was conducted to investigate the role of endotoxins in the pathogenesis of colon polyps through a case-control study. A total of 145 subjects (74 subjects in the polyp group and 71 subjects in the control group) had undergone a colonoscopy. Age, body mass index (BMI) and endotoxin levels were found to be significantly higher in the polyp group than in the control group. The endotoxin level was still significantly higher in the polyp group than in the control group, even after age and BMI had been adjusted (polyp group 0.108 ± 0.007 EU/mL, control group 0.049 ± 0.008 EU/mL, P < 0.001). In subgroup analysis, the endotoxin level significantly increased in accordance with the number of colon polyps (one-polyp group, 0.088 ± 0.059 EU/mL; two-polyp group, 0.097 ± 0.071 EU/mL; three-or-more-polyp group, 0.149 ± 0.223 EU/mL). The endotoxin levels also significantly increased in groups with tubular adenoma with high-grade dysplasia (hyperplastic polyp group, 0.109 ± 0.121 EU/mL; tubular adenoma with low grade dysplasia group, 0.103 ± 0.059 EU/mL; tubular adenoma with high grade dysplasia group, 2.915 ± 0.072 EU/mL). In conclusion, the serum level of endotoxins is quantitatively correlated with colon polyps.

  15. Factors associated with obesity: a case-control study of young adult Singaporean males.

    PubMed

    Shi, Haiyuan; Jiang, Bo; Wei Sim, Joshua Dao; Chum, Zhi Zhen; Ali, Noreffendy Bin; Toh, Mun Heng

    2014-10-01

    A case-control study among Singapore Armed Forces' newly enlisted Servicemen was conducted to examine factors associated with male obesity. Four hundred and fifty-nine individuals from the Obese Basic Military Training program were selected as "cases" (average age: 19.5, body mass index: 30.4) and another 340 individuals were selected from the Normal Basic Military Training program as "controls" (average age: 19.3, body mass index: 21.4). Information such as family background, socioeconomic factors, and lifestyle practices were captured using facilitator-led questionnaires. Several variables were significantly associated with obesity after adjustments for possible confounders. These include childhood obesity (odds ratio [OR] = 2.06), less than an hour of exercise per day (OR = 2.97), Indian ethnicity (OR = 2.22), specific education backgrounds (especially that of Institute of Technical Education-OR = 2.75), father's employment at nonmanagerial/professional jobs (OR = 1.52), mother's employment at managerial/professional jobs (OR = 2.02), regular smoking (OR = 1.73) and alcohol consumption (OR = 2.26), 6 hours or less of sleep (OR = 3.73), obesity among family members (OR = 1.86 for mother; OR = 2.98 for siblings), parental history of diabetes mellitus (OR = 2.22 for father; OR = 2.70 for mother), and eating at inexpensive local food stalls (OR = 1.82). Our study found that a number of factors, ranging from personal and family backgrounds to lifestyle choices, were significantly associated with obesity among male youths.

  16. Homicide in children and adolescents: a case-control study in Recife, Brazil.

    PubMed Central

    Falbo, G. H.; Buzzetti, R.; Cattaneo, A.

    2001-01-01

    OBJECTIVE: The homicide rate for children and adolescents in Recife, Brazil, mostly caused by firearms, is one of the highest that has been reported. The present case-control study was designed to identify factors that were potentially modifiable through preventive interventions. METHODS: Cases were 255 homicide victims under 20 years of age, who had died in 1997 and been identified at the Institute of Forensic Medicine, Police Department, Recife, and whose relatives were interviewed by two community health workers when they claimed the corpse. The 255 controls were neighbours of the cases, paired by age and sex to them, and identified within one week of identification of each case, and whose relatives were interviewed by a third community health worker. FINDINGS: The overall homicide rate in Recife for under-20-year-olds in 1997 was 49 per 100,000; among males aged 15-19 years it was 324 per 100,000. Firearms were responsible for 97% of deaths. After multivariate logistic regression, history of personal police records (odds ratio (OR) = 18.65; 95% confidence interval (CI) = 1.91-182.50), use of illicit drugs (OR = 7.48; 95% CI = 1.86-30.17), tap water at home (OR = 7.30; 95% CI = 1.80-29.59), and maternal age at birth over 26 years (OR = 3.98; 95% CI = 1.79-8.84) were identified as risk factors, while higher education (OR = 0.22; 95% CI = 0.11-0.43), religious practice (OR = 0.25; 95% CI = 0.10-0.65), and presence of the father in the household (OR = 0.28; 95% CI = 0.09-0.81) were protective factors. CONCLUSION: Public health authorities should plan preventive interventions based on the findings of this study and should control the acquisition, possession and carrying of firearms. PMID:11217662

  17. A molecular case-control study of the Merkel cell polyomavirus in colon cancer.

    PubMed

    Campello, Cesare; Comar, Manola; D'Agaro, Pierlanfranco; Minicozzi, Anna; Rodella, Luca; Poli, Albino

    2011-04-01

    To explore the putative role of the Merkel cell polyomavirus in human colon cancer, a prospective molecular case-control study was undertaken in patients and their relatives enrolled during a screening program. Fresh tissue samples from 64 cases of colon cancer (mean age 69.9 ± 11.0 years; 40 males) and fresh biopsies from 80 relatives (mean age 53.7 ± 8.6 years; 43 male; 55 son/daughter, 23 brother/sister, 2 parents) were analyzed by PCR and sequencing. Pre-cancerous lesions, namely adenomas and polyps, were detected in 15 (18.8%) and 9 (11.2%) of the controls, respectively. In addition, 144 blood samples were examined. Merkel cell polyomavirus DNA was detected in 6.3% of cases and 8.8% of controls. This difference was not statistically significant in the logistic regression analysis, after adjustment for age. Whereas blood samples from both cases and controls tested negative, the DNA Merkel cell polyomavirus was identified in 12.5% of adenoma/polyp tissues. No statistically significant difference was found when prevalence rates of Merkel cell polyomavirus in normal, pre-cancerous and cancer tissues were compared. Sequence analysis of the viral LT3 and VP1 regions showed high homology (>99%) with those of strains circulating worldwide, especially with genotypes detected in France. The findings of this survey are consistent with the hypothesis that the Merkel cell polyomavirus, in addition to other human polyomaviruses, can be recovered frequently from the gastrointestinal tract, because it is transmitted throughout the fecal-oral route. Moreover, the study does not indicate a role for Merkel cell polyomavirus in the genesis of colon cancer.

  18. Understanding patient-initiated frequent attendance in primary care: a case-control study.

    PubMed Central

    Báez, K; Aiarzaguena, J M; Grandes, G; Pedrero, E; Aranguren, J; Retolaza, A

    1998-01-01

    BACKGROUND: Frequent attendance, which accounts for a high proportion of the general practitioner's (GP's) workload, is still poorly understood. AIM: To assess the association and impact of exposure to chronic physical illness, mental disorders, life stress, and sociodemographic factors on the frequent attendance of primary health care medical services. METHOD: Nine general practices in Bizkaia, Spain, participated in a case-control study. Cases were patients who exceeded the 90th percentile in the distribution of the number of visits that they made on their own initiative from January 1993 to March 1994. Controls were those for whom a single, patient-initiated consultation was registered. A total of 102 cases and 100 controls were selected by stratified sampling proportional to the size of each practice. We estimated odds ratios and population attributable fractions for frequent attendance in relation to being exposed to the study variables, adjusted by demographic characteristics by means of logistic regression analysis. RESULTS: Medium-high life stress (adjusted odds ratio (AOR) = 4.5, 95% confidence interval (CI) = 1.7-12.8), chronic physical illness (AOR = 3.1; 95% CI = 1.4-6.9), mental disorder (AOR = 2.5; 95% CI = 1.3-5.1), and age were associated with patient-initiated frequent attendance. The adjusted population attributable fraction for chronic physical illness was 41%, 30.9% for mental disorder, and 15.2% for life stress. CONCLUSION: There is evidence that patient-initiated frequent attendance is related to genuine physical and psychosocial needs; therefore, recognition requires a bio-psychosocial approach on the part of GP. PMID:10198500

  19. Anesthesia and Incident Dementia: A Population-Based Nested Case-Control Study

    PubMed Central

    Sprung, Juraj; Jankowski, Christopher J.; Roberts, Rosebud O.; Weingarten, Toby N.; Aguilar, Andrea L.; Runkle, Kayla J.; Tucker, Amanda K.; McLaren, Kathryn C.; Schroeder, Darrell R.; Hanson, Andrew C.; Knopman, David S.; Gurrieri, Carmelina; Warner, David O.

    2013-01-01

    Objective To test the hypothesis that exposure to procedures requiring general anesthesia during adulthood is not significantly associated with incident dementia using a retrospective, population-based, nested case-controlled study design. Patients and Methods Using the Rochester Epidemiology Project and the Mayo Clinic Alzheimer's Disease Patient Registry, residents of Olmsted County, Minnesota, diagnosed with dementia between January 1, 1985, and December 31, 1994, were identified. For each incident case, a sex and age matched control was randomly selected from the general pool of Olmsted County residents who were dementia-free in the index year of dementia diagnosis. Medical records were reviewed to determine exposures to procedures requiring anesthesia after the age of 45 and prior to the index year. Data were analyzed using logistic regression. Results 877 cases of dementia, each with a corresponding control, were analyzed. Among dementia cases, 615 (70%) individuals underwent 1,681 procedures requiring general anesthesia, and 636 controls (73%) underwent 1,638 procedures. When assessed as a dichotomous variable, anesthetic exposure was not significantly associated with dementia (OR 0.89, 95% CI 0.73-1.10; P = 0.27). In addition, no significant association was found (P = 0.51) when exposure was quantified as number of procedures (OR = 0.87, 0.86, and 1.0 for 1, 2-3, and ≥4 exposures compared to none, respectively). Conclusion This study found no significant association between exposure to procedures requiring general anesthesia after the age of 45 years and incident dementia. PMID:23642337

  20. Environmental risk factors contributing to traffic accidents in children: a case-control study.

    PubMed

    Jamshidi, Ensiyeh; Moradi, Ali; Majdzadeh, Reza

    2016-06-09

    The aim of this study is to identify environmental risk factors related to road accidents in children of Tehran. This case-control study was performed in 2013. The cases were injured pedestrians aged 5-15 who were admitted to major hospitals supervised by Tehran University of Medical Sciences. The sample size for the cases was 273 and for the control group was 546. For the completeness of the clusters, 7 extra persons in case (total = 280) and 14 persons (total = 560) in control group were included. The interference of confounding variables assessed through forward conditional logistic regression. Result shows occurrence of traffic accidents was significantly associate with the width of the alleys or (<5 m: OR = 8.4, 95% CI: 3.3-21.5; 5-8 m: OR = 4.7, 95% CI: 1.8-12.2), distance from home to school((<100 m: OR = 1.7, 95% CI: 1.0-2.8), existence of parking lot (OR = 1.5, 95% CI: 1.0-2.3), traffic congestion (OR = 4.1, 95% CI: 2.6-6.4), traffic speed (OR = 2.1, 95% CI: 1.3-3.2) and existence of pedestrian bridges(OR = 4.2, 95% CI: 2.6-6.8). In the light of the important role of environmental factors in the occurrence of child traffic accidents, alleviating structural risk factors in addition to education and enforcement need more systematic efforts and planning by policymakers and urban planners to attain pedestrian safety goals.

  1. The Relevance of Maternal Socioeconomic Characteristics for Low Birth Weight – a Case-Control Study

    PubMed Central

    Altenhöner, T.; Köhler, M.; Philippi, M.

    2016-01-01

    Introduction: The number of children born underweight (low birth weight, LBW) is increasing despite extensive prevention and screening programmes. The cost is high for the health system, and affected children are burdened with health predictors that can affect them negatively throughout their lives. This study investigates to what extent socioeconomic factors, in addition to known medical causes and the health behaviour of pregnant women, influence LBW. Materials and Methods: In this case-control study 131 mothers of singletons with a birth weight ≤ 2500 g (cases) and 323 mothers of normal birth weight babies (controls) were interviewed with respect to socioeconomic status, health behaviour and stress in the workplace. Medical data were collected by specialist staff using a questionnaire. Results: Independent of medical diagnosis and health behaviour, women with lower level education (OR [95 % CI] = 2.24 [1.12; 4.51]) and those who were not working (OR [95 % CI] = 1.82 [1.10; 3.00]) were more likely to have an LBW baby. No effect was shown for immigrant background (OR [95 % CI] = 1.14 [0.59; 2.21]) or stress in the workplace (OR [95 % CI] = 1.17 [0.90; 1.51]). Discussion and Conclusion: These results show that the association between social and health inequalities starts from before birth. In order to reduce the rising number of babies born underweight, socioeconomic determinants in the care and supervision of pregnant women should systematically receive more attention to enable appropriate early preventive strategies to be implemented. PMID:27065486

  2. Risk of lung cancer following nonmalignant respiratory conditions: evidence from two case-control studies in Montreal, Canada.

    PubMed

    Ramanakumar, Agnihotram V; Parent, Marie-Elise; Menzies, Dick; Siemiatycki, Jack

    2006-07-01

    There has been conflicting evidence concerning possible associations between several nonmalignant respiratory diseases and subsequent risk of lung cancer. In the context of two large population based case-control studies of lung cancer carried out in Montreal, we were able to study the possible relationships between a previous history of lung disease and subsequent risk of lung cancer. Interviews for Study I were conducted in 1979-1986 (755 cases and 512 controls) and included questions on asthma and tuberculosis. Interviews for Study II were conducted in 1996-2001 (1205 cases and 1541 controls) and included questions on asthma, tuberculosis, emphysema, and pneumonia. Lung cancer risk was analysed in relation to each condition, adjusting for several potential confounders, including smoking in a three-variable parametrization. To avoid any possible confusion between the respiratory conditions and early symptoms of lung cancer, conditions occurring in the 3 years before diagnosis of cancer were discounted. For asthma there was no evidence of an association. For TB the evidence was inconsistent between Study I and Study II. For both pneumonia and emphysema, there were significantly elevated odds ratios, with point estimates in the range of 1.6-2.4. Our results support the hypothesis that some nonmalignant respiratory diseases may be independent risk factors for lung cancer.

  3. A Case-Control Study on the Behavior Status of Rural Left-Behind Children in China

    ERIC Educational Resources Information Center

    Zhi-xin, Yang; Yu-qi, Zheng

    2012-01-01

    The present study is aiming to exploring the behavior status of rural left-behind children in China. In a case-control study, we used Rutter Children's Behavior Questionnaire for teacher to measure behavior status of children in left-behind group and control group. Furthermore, we also compared behavior status of children in different age groups…

  4. An Unmatched Case-Control Study of Nearly Lethal Suicide Attempts in Houston, Texas: Research Methods and Measurements.

    ERIC Educational Resources Information Center

    Kresnow, Marcie-jo; Ikeda, Robin M.; Mercy, James A.; Powell, Kenneth E.; Potter, Lloyd B.; Simon, Thomas R.; Lee, Roberta K.; Frankowski, Ralph F.

    2002-01-01

    This article details the research methods and measurements used in conducting a population-based, case-control study of nearly lethal suicide attempts among persons aged 13-34 years. This study was designed to extend understanding of suicidal behavior and prevention activities beyond identification of mental illnesses. Overall strengths and…

  5. Mortality from Circulatory System Diseases among French Uranium Miners: A Nested Case-Control Study.

    PubMed

    Drubay, Damien; Caër-Lorho, Sylvaine; Laroche, Pierre; Laurier, Dominique; Rage, Estelle

    2015-05-01

    A significant association has been observed between radon exposure and cerebrovascular disease (CeVD) mortality among French uranium miners, but risk factors for circulatory system diseases (CSD) have not been previously considered. We conducted new analyses in the recently updated (through 2007) French cohort of uranium miners (n = 5,086), which included 442 deaths from CSD, 167 of them from ischemic heart disease (IHD) and 105 from CeVD. A nested case-control study was then set up to collect and investigate the influence of these risk factors on the relationships between mortality from CSD and occupational external gamma ray and internal ionizing radiation exposure (radon and long-lived radionuclides) in this updated cohort. The nested case-control study included miners first employed after 1955, still employed in 1976 and followed up through 2007. Individual information about CSD risk factors was collected from medical files for the 76 deaths from CSD (including 26 from IHD and 16 from CeVD) and 237 miners who had not died of CSD by the end of follow-up. The exposure-risk relationships were assessed with a Cox proportional hazard model weighted by the inverse sampling probability. A significant increase in all CSD and CeVD mortality risks associated with radon exposure was observed in the total cohort [hazard ratios: HRCSD/100 working level months (WLM) = 1.11, 95% confidence interval (1.01; 1.22) and HRCeVD/100 WLM = 1.25 (1.09; 1.43), respectively]. A nonsignificant exposure-risk relationship was observed for every type of cumulative ionizing radiation exposure and every end point [e.g., HRCSD/100WLM = 1.43 (0.71; 2.87)]. The adjustment for each CSD risk factor did not substantially change the exposure-risk relationships. When the model was adjusted for overweight, hypertension, diabetes, hypercholesterolemia and smoking status, the HR/100WLM for CSD, for example, was equal to 1.21 (0.54; 2.75); and when it was adjusted for risk factors selected with the

  6. Correlation between nutritional biomarkers and breast cancer: a case-control study.

    PubMed

    Zaroukian, S; Pineault, R; Gandini, S; Lacroix, A; Ghadirian, P

    2005-06-01

    A case-control study to explore associations between retinoids, tocopherols, total and beta-carotenes and breast cancer was conducted by analysing concentrations of these biomarkers in adipose tissue, cheek cells and plasma. A total of 414 French-Canadians in Montreal with new diagnoses of breast cancer were age-matched to 429 population-based controls. Subjects were interviewed using a questionnaire, and biological samples from 287 cases and 112 controls were collected within 3 months of the diagnosis. Mean beta carotene concentrations in cheek cells were significantly lower among controls. Odds ratios (ORs) from logistic regression analysis were used to compare higher and lower tercile concentrations. Significant positive associations were observed in adipose tissue for retinoid [OR=2.11; 95% CI (1.09-4.08)] and beta carotene [OR=3.18; 95% CI (1.70-5.93)]; in cheek cells for beta carotene [OR=2.22; 95% CI (1.21-4.50)] and for total carotenes [OR=2.94; 95% CI (1.59-5.42)] and in plasma for beta carotene [OR=1.53; 95% CI (0.80-2.93)] and total carotenes [OR=1.04; 95% CI (0.53-2.05)]. Among the control groups, significant Pearson correlations were observed between cheek cells and adipose tissue for total carotenes (r=0.27; p=0.01) and cheek cells and plasma (r=0.22; p=0.04). In contrast to previous works, this study shows that high concentrations of retinoids and carotenes in adipose tissue and cheek cells are associated with increased risk of breast cancer. However, all these studies are limited by small sample size. Although our study tested a limited number of controls, important associations were observed. These results suggest that the effect of disease on biomarkers is fundamental to the interpretation of epidemiological data. We suggest either that the high levels of these biomarkers found in cancer patients in this study may be due to the disease process that affects the pharmacokinetics of the biomarker or that the disease causes a change in dietary habits

  7. Use of wireless phones and the risk of salivary gland tumours: a case-control study.

    PubMed

    Söderqvist, Fredrik; Carlberg, Michael; Hardell, Lennart

    2012-11-01

    The last decades of increasing use of wireless phones, including mobile as well as cordless desktop phones, have led to concerns about the potential carcinogenic effects of radiofrequency electromagnetic fields. Among the most exposed areas of the body when the phone is used for talking are the salivary glands, mainly the parotid gland, located in front of the ear. The objective of this case-control study was to assess whether the use of wireless phones is associated with an increased risk of tumour at this site. Sixty-nine patients with salivary gland tumours (63 with a parotid gland tumour) and 262 randomly recruited controls were included. Unconditional logistic regression - adjusted for age at diagnosis, sex, year of diagnosis and socioeconomic index - was used to produce odds ratios and 95% confidence intervals. The use of wireless phones was not associated with an overall increased risk of salivary gland tumours, odds ratio 0.8, 95% confidence interval 0.4-1.5. Neither was there an increased risk for the different phone types when calculated separately nor was there an increased risk for different latencies or when cumulative use was divided into three groups (1-1000, 1001-2000 and >2000 h). The overall results were similar for the risk of parotid gland tumours. In conclusion, our data add to the evidence against there being an increased risk for parotid gland tumours associated with light-to-moderate use of wireless phones and for less than 10 years of use but offers little information on risk related to more prolonged and/or heavy use.

  8. Case-control study of oestrogen replacement therapy and risk of cervical cancer.

    PubMed Central

    Parazzini, F.; La Vecchia, C.; Negri, E.; Franceschi, S.; Moroni, S.; Chatenoud, L.; Bolis, G.

    1997-01-01

    OBJECTIVE: To examine the relation between use of oestrogen replacement therapy and risk of cervical cancer. DESIGN: Case-control study. SETTING: Northern Italy. SUBJECTS: 645 women aged 40-75 years with cervical cancer admitted between 1981 and 1993 to university and general hospitals. The control group consisted of 749 women aged 40-75 years admitted to the same hospitals with acute conditions judged to be unrelated to any of the known or suspected risk factors for cervical cancer. MAIN OUTCOME MEASURES: Use of oestrogen replacement therapy and risk of cervical cancer. RESULTS: 40 cases versus 86 controls had ever used oestrogens, and the corresponding multivariate odds ratio was 0.5 (95% confidence interval 0.3 to 0.8). The odds ratios of cervical cancer decreased with duration of use, being 0.6 (0.4 to 1.1) for less than 12 months' use and 0.5 (0.2 to 1.0) for use for 12 months or more compared with never users. The protection tended to be somewhat stronger for women reporting first oestrogen use before age 50. The odds ratio was 0.9 (0.5 to 1.7) for women who had taken oestrogens within the past 10 years and 0.4 (0.2 to 0.7) for those who had taken them 10 or more years ago. CONCLUSION: These findings suggest that exogenous oestrogens do not increase the risk of cervical cancer and may decrease the risk. PMID:9240046

  9. Case-control study of prostatic cancer in employees of the United Kingdom Atomic Energy Authority.

    PubMed Central

    Rooney, C; Beral, V; Maconochie, N; Fraser, P; Davies, G

    1993-01-01

    OBJECTIVE--To investigate the relation between risk of prostatic cancer and occupational exposures, especially to radionuclides, in employees of the United Kingdom Atomic Energy Authority. DESIGN--Case-control study of men with prostatic cancer and matched controls. Information about sociodemographic factors and exposures to radionuclides and other substances was abstracted and classified for each subject from United Kingdom Atomic Energy Authority records without knowledge of who had cancer. SUBJECTS--136 men with prostatic cancer diagnosed between 1946 and 1986 and 404 matched controls, all employees of United Kingdom Atomic Energy Authority. MAIN OUTCOME MEASURES--Documented or possible contamination with specific radionuclides. RESULTS--Risk of prostatic cancer was significantly increased in men who were internally contaminated with or who worked in environments potentially contaminated by tritium, chromium-51, iron-59, cobalt-60, or zinc-65. Internal contamination with at least one of the five radionuclides was detected in 14 men with prostatic cancer (10%) and 12 controls (3%) (relative risk 5.32 (95% confidence interval 1.87 to 17.24). Altogether 28 men with prostatic cancer (21%) and 46 controls (11%) worked in environments potentially contaminated by at least one of the five radionuclides (relative risk 2.36 (1.26 to 4.43)); about two thirds worked at heavy water reactors (19 men with prostatic cancer and 32 controls (relative risk 2.13 (1.00 to 4.52)). Relative risk of prostatic cancer increased with increasing duration of work in places potentially contaminated by these radionuclides and with increasing level of probable contamination. Prostatic cancer was not associated with exposure to plutonium, uranium, cadmium, boron, beryllium, or organic or inorganic chemicals. CONCLUSIONS--Risk of prostatic cancer risk was increased in United Kingdom Atomic Energy Authority workers who were occupationally exposed to tritium, 51Cr, 59Fe, 60Co, or 65Zn. Exposure to

  10. Bacteraemic urinary tract infections may mimic respiratory infections: a nested case-control study.

    PubMed

    Denis, E; Martis, N; Guillouet-de Salvador, F; Demonchy, E; Degand, N; Carles, K; Roger, P-M

    2016-10-01

    Daily practice suggests that respiratory signs may be observed in bacteraemic urinary infections (BUI). Our objective was to search for an association between the presence of respiratory symptoms and the bacteraemic nature of urinary tract infections (UTI). A nested case-control study was carried out based on our computerised dashboard from January 2011 to June 2015. Cases were defined as patients with a BUI due to Enterobacteriaceae species, identified in blood and urine cultures. Controls had fever and a positive urinary sample but sterile blood cultures (NBUI) and a final diagnosis of urinary infection. Patients from the BUI group were 1:1 matched to the NBUI group according to four parameters: age, gender, cardiovascular and pulmonary comorbid conditions. Subjects with cognitive impairment limiting clinical accuracy and those with healthcare-associated infections were excluded. We compared systematically recorded respiratory and urinary symptoms between groups: signs on auscultation, dyspnoea, chest pain, cough and sputum, dysuria with burning, pollakiuria, flank or costovertebral angle tenderness and ischuria. One hundred BUI were compared to 100 NBUI, both groups exhibiting a similar rate for all considered comorbid conditions. In the BUI group, 58 % showed at least one respiratory sign vs. 20 % in the NBUI group, p < 0.001, while urinary signs were less frequent: 54 % vs. 71 %, p = 0.013. In the multivariate analysis, BUI was associated with the presence of abnormal pulmonary auscultation [adjusted odds ratio (AOR), 5.91; p < 0.001] and a trend towards less urinary symptoms (AOR, 1.58; p = 0.058). Patients with BUI presented with significantly more respiratory signs, which overshadowed urinary symptoms, compared to those with non-bacteraemic UTI. Such observations impact clinical decision-making.

  11. Human papillomavirus infection and oral cancer: a case-control study in Montreal, Canada.

    PubMed

    Pintos, Javier; Black, Martin J; Sadeghi, Nader; Ghadirian, Parviz; Zeitouni, Anthony G; Viscidi, Raphael P; Herrero, Rolando; Coutlée, François; Franco, Eduardo L

    2008-03-01

    The objective of the present study was to examine the association between human papillomavirus (HPV) infection and risk of developing oral cancer. The investigation followed a hospital-based case-control design. Cases consisted of newly diagnosed patients with squamous cell carcinoma of the oral cavity and oropharynx. Controls were frequency matched to cases on gender, age, and hospital. Subjects were interviewed to elicit information on putative risk factors. Oral exfoliated cells were tested for detection of HPV DNA by the PGMY09/11 polymerase chain reaction protocol. Serum antibodies against HPV 16, 18, and 31 viral capsids were detected using an immunoassay technique. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI) of oral cancer according to HPV exposure variables. HPV DNA was detected in 19% of cases (14 out of 72), and 5% of controls (six out of 129). Among tonsil-related cancers (palatine tonsil and base of tongue) viral DNA was detected in 43% of cases (nine out of 21). The OR for tonsil-related cancers for high-risk HPV types was 19.32 (95%CI: 2.3-159.5), after adjustment for socio-demographic characteristics, tobacco, and alcohol consumption. The equivalent OR for HPV 16 seropositivity was 31.51 (95%CI: 4.5-219.7). The ORs of non-tonsillar oral cancers for high risk HPV DNA in oral cells and for seropositivity were 2.14 (95%CI: 0.4-13.0) and 3.16 (95%CI: 0.8-13.0), respectively. These results provide evidence supporting a strong causal association between HPV infection and tonsil-related cancers. The evidence for an etiologic link is less clear for non-tonsillar oral cancers.

  12. A nested case-control study of kidney cancer among refinery/petrochemical workers

    SciTech Connect

    Gamble, J.F.; Pearlman, E.D.; Nicolich, M.J.

    1996-06-01

    A nested case-control study was designed to evaluate whether a nearly twofold excess of kidney cancer among workers at a refinery/petrochemical plant was associated with cumulative exposure to C{sub 2}-C{sub 5} saturated, C{sub 2}-C{sub 5} unsaturated, C{sub 6}-C{sub 10} aliphatic saturated, C{sub 6}-C{sub 10} aliphatic unsaturated, and C{sub 6}-C{sub 10} aromatic process streams. Nonoccupational risk factors were body mass index association with cumulative exposure or tenure as estimated by conditional logistic regression and adjusted for nonoccupational risk factors. Categorical analysis showed increased odds ratios only in the second (low) and fourth (high) quartiles compared to the first quartile reference group of lowest exposed workers, and a three-quarter-fold increased odds ratio for >32 years` tenure compared to the <25-year reference group. The number of cases was small with wide confidence intervals around estimate of risk, so the possibility of an exposure-response trend cannot be ruled out. Multivariate analysis identified overweight (high BMI; p<0.01) as the most important risk factor in this data set, followed by tenure and increased blood pressure. There was a weak association with current smoking, but not with pack-years smoked. The risk of kidney cancer for a nonsmoker with normal blood pressure but 25% overweight was increased about 2.6-fold (95% CI = 1.2-5.4). The risk of kidney cancer for a nonsmoker of normal weight with high blood pressure (e.g., 150/110), was increased about 4.5 (95% CI, 0.8-26). 49 refs., 3 figs., 8 tabs.

  13. Early pregnancy sex steroids and maternal breast cancer: a nested case-control study.

    PubMed

    Fortner, Renée T; Schock, Helena; Kaaks, Rudolf; Lehtinen, Matti; Pukkala, Eero; Lakso, Hans-Åke; Tanner, Minna; Kallio, Raija; Joensuu, Heikki; Grankvist, Kjell; Zeleniuch-Jacquotte, Anne; Toniolo, Paolo; Lundin, Eva; Surcel, Helja-Marja

    2014-12-01

    Pregnancy, parity, and circulating steroid hormone levels are associated with risk of breast cancer, but little is known about hormone concentrations during pregnancy and subsequent breast cancer risk. We evaluated early pregnancy (<140 days gestation) serum estradiol, estrone, progesterone, and testosterone and breast cancer risk in a nested case-control study in the Finnish Maternity Cohort. The cohort includes 98% of pregnancies registered in Finland since 1983. Individuals with samples collected in the first pregnancy leading to a live birth were eligible. Breast cancer cases (n = 1,199) were identified through linkage with the Finnish Cancer Registry; 2,281 matched controls were selected using incidence density sampling. ORs were calculated using conditional logistic regression. Hormone concentrations were not associated with breast cancer overall. Estradiol was positively associated with risk of breast cancer diagnosed age <40 [4th vs. 1st quartile OR 1.60 (1.07-2.39); Ptrend = 0.01], and inversely associated with breast cancer diagnosed at age ≥40 [4th vs. 1st quartile OR 0.71 (0.51-1.00); Ptrend = 0.02]. Elevated concentrations of the steroid hormones were associated with increased risk of estrogen receptor (ER)- and progesterone receptor (PR)-negative tumors in women age <40 at diagnosis. We observed no association between steroid hormones and ER(+)/PR(+) disease. These data suggest a positive association between high concentrations of early pregnancy steroid hormones and risk of ER(-)/PR(-) breast cancer in women diagnosed age <40, and an inverse association for overall breast cancer diagnosed age ≥40. Further research on pregnancy hormones and risk of steroid receptor-negative cancers is needed to further characterize this association.

  14. Isoflavone and Soyfood Intake and Colorectal Cancer Risk: A Case-Control Study in Korea

    PubMed Central

    Shin, Aesun; Lee, Jeonghee; Lee, Jeeyoo; Park, Moon Sung; Park, Ji Won; Park, Sung Chan; Oh, Jae Hwan; Kim, Jeongseon

    2015-01-01

    We aimed to assess the relationship between dietary soyfood and isoflavone intake and colorectal cancer risk in a case-control study. A total of 901 colorectal cancer cases and 2669 controls were recruited at the National Cancer Center, Korea. A semi-quantitative food frequency questionnaire was used to assess the usual dietary habits, and the isoflavone intake level was estimated from five soyfood items. A high intake of total soy products, legumes, and sprouts was associated with a reduced risk for colorectal cancer in men and women, although the middle quartiles of intake of total soy products were associated with an elevated risk. In contrast, a high intake of fermented soy paste was associated with an elevated risk for colorectal cancer in men. The groups with the highest intake quartiles of isoflavones showed a decreased risk for colorectal cancer compared to their counterparts with the lowest intake quartiles in men (odds ratio (OR): 0.67, 95% confidence interval (CI): 0.51–0.89) and women (OR: 0.65, 95% CI: 0.43–0.99). The reduced risk for the highest intake groups persisted for distal colon cancer in men and rectal cancer in women. The association between soyfood intake and colorectal cancer risk was more prominent among post-menopausal women than pre-menopausal women. In conclusion, a high intake of total soy products or dietary isoflavones was associated with a reduced risk for overall colorectal cancer, and the association may be more relevant to distal colon or rectal cancers. PMID:26575841

  15. Risk factors for recurrent wheezing in infants: a case-control study

    PubMed Central

    de Sousa, Roberta Barros; Medeiros, Décio; Sarinho, Emanuel; Rizzo, José Ângelo; Silva, Almerinda Rêgo; Bianca, Ana Carolina Dela

    2016-01-01

    ABSTRACT OBJECTIVE To evaluate the association between recurrent wheezing and atopy, the Asthma Predictive Index, exposure to risk factors, and total serum IgE levels as potential factors to predict recurrent wheezing. METHODS A case-control study with infants aged 6-24 months treated at a specialized outpatient clinic from November 2011 to March 2013. Evaluations included sensitivity to inhalant and food antigens, positive Asthma Predictive Index, and other risk factors for recurrent wheezing (smoking during pregnancy, presence of indoor smoke, viral infections, and total serum IgE levels). RESULTS We evaluated 113 children: 65 infants with recurrent wheezing (63.0% male) with a mean age of 14.8 (SD = 5.2) months and 48 healthy infants (44.0% male) with a mean age of 15.2 (SD = 5.1) months. In the multiple analysis model, antigen sensitivity (OR = 12.45; 95%CI 1.28–19.11), positive Asthma Predictive Index (OR = 5.57; 95%CI 2.23–7.96), and exposure to environmental smoke (OR = 2.63; 95%CI 1.09–6.30) remained as risk factors for wheezing. Eosinophilia ≥ 4.0% e total IgE ≥ 100 UI/mL were more prevalent in the wheezing group, but failed to remain in the model. Smoking during pregnancy was identified in a small number of mothers, and secondhand smoke at home was higher in the control group. CONCLUSIONS Presence of atopy, positive Asthma Predictive Index and exposure to environmental smoke are associated to recurrent wheezing. Identifying these factors enables the adoption of preventive measures, especially for children susceptible to persistent wheezing and future asthma onset. PMID:27143615

  16. Case-control study and case series of pseudohyperphosphatemia during exposure to liposomal amphotericin B.

    PubMed

    Bohm, Nicole M; Hoover, Katherine C; Wahlquist, Amy E; Zhu, Yusheng; Velez, Juan Carlos Q

    2015-11-01

    Pseudohyperphosphatemia due to an interaction between liposomal amphotericin B and the Beckman Coulter PHOSm assay occurs sporadically and remains underrecognized in clinical practice. This retrospective case-control study compares the incidences of hyperphosphatemia in adult inpatients exposed to liposomal amphotericin B or a triazole. A case series of patients with confirmed pseudohyperphosphatemia is described. A total of 80 exposures to liposomal amphotericin B and 726 exposures to triazoles were identified. Among subjects without chronic kidney disease and no concomitant acute kidney injury, hyperphosphatemia occurred more often during liposomal amphotericin B therapy than during triazole therapy (40% [14/35 cases] versus 10% [47/475 cases] of cases; P < 0.01; adjusted odds ratio, 5.2 [95% confidence interval {CI}, 2.3 to 11.9]). Among individuals with chronic kidney disease and no concomitant acute kidney injury, hyperphosphatemia also occurred more often during liposomal amphotericin B exposure (59% [10/17 cases] versus 20% [34/172 cases] of cases; P < 0.01; adjusted odds ratio, 6.0 [95% CI, 2.0 to 18.0]). When acute kidney injury occurred during antifungal exposure, the frequencies of hyperphosphatemia were not different between treatments. Seven episodes of unexpected hyperphosphatemia during liposomal amphotericin B exposure prompted a confirmatory test using an endpoint-based assay that found lower serum phosphorus levels (median difference of 2.5 mg/dl [range, 0.6 to 3.6 mg/dl]). Liposomal amphotericin B exposure confers a higher likelihood of developing hyperphosphatemia than that with exposure to a triazole antifungal, which is likely attributable to pseudohyperphosphatemia. Elevated phosphorus levels in patients receiving liposomal amphotericin B at institutions using the Beckman Coulter PHOSm assay should be interpreted cautiously.

  17. High Seroprevalence of Toxoplasma Gondii Infection in Female Sex Workers: A Case-Control Study

    PubMed Central

    Alvarado-Esquivel, Cosme; Sánchez-Anguiano, Luis Francisco; Hernández-Tinoco, Jesús; Arreola-Cháidez, Emilio; López, Juan; Salcido-Meraz, Karla Itzel; Estrada-Martínez, Sergio; Navarrete-Flores, José Antonio; Pérez-Álamos, Alma Rosa; Hernández-Ochoa, Marcia; Rábago-Sánchez, Elizabeth; Liesenfeld, Oliver

    2015-01-01

    Through an age- and sex-matched case-control study, we sought to determine whether female sex workers have an increased risk of Toxoplasma gondii exposure and to determine the sociodemographic, work, clinical, and behavioral characteristics of these workers associated with T. gondii exposure. Female workers (n = 136) and controls (n = 272) were examined with enzyme-linked immunoassays (EIA) for the presence of anti-Toxoplasma IgG and IgM antibodies. IgM positive sera were additionally tested with enzyme linked-fluorescence immunoassay (ELFA). Anti-T. gondii IgG antibodies were found in 21 (15.44%) of 136 cases and in 10 (3.67%) of 272 controls (OR = 4.05; 95% CI: 1.84–8.89; P = 0.0001). Anti-T. gondii IgG levels higher than 150 IU/ml were found in 13 (9.6%) of 136 cases and in 8 (2.9%) of 272 controls (P = 0.007). Anti-T. gondii IgM antibodies were found in two cases and in six controls by EIA, but all were negative by ELFA. T. gondii seropositivity was associated with being born out of Durango State (OR = 10.47; 95% CI: 2.9–36.8; P < 0.01), injuries during sex work (OR = 6.30; 95% CI: 1.1–33.7; P = 0.03), and soil contact (OR = 4.11; 95% CI: 1.2–14.0; P = 0.02). This is the first report of an association of T. gondii infection and female sex workers. PMID:26716017

  18. Neonatal risk factors for cerebral palsy in very preterm babies: case-control study.

    PubMed Central

    Murphy, D. J.; Hope, P. L.; Johnson, A.

    1997-01-01

    OBJECTIVE: To identify neonatal risk factors for cerebral palsy among very preterm babies and in particular the associations independent of the coexistence of antenatal and intrapartum factors. DESIGN: Case-control study. SETTING: Oxford health region. SUBJECTS: Singleton babies born between 1984 and 1990 at less than 32 weeks' gestation who survived to discharge from hospital: 59 with cerebral palsy and 234 randomly selected controls without cerebral palsy. MAIN OUTCOME MEASURES: Adverse neonatal factors expressed as odds ratios and 95% confidence intervals. RESULTS: Factors associated with an increased risk of cerebral palsy after adjustment for gestational age and the presence of previously identified antenatal and intrapartum risk factors were patent ductus arteriosus (odds ratio 2.3; 95% confidence interval 1.2 to 4.5), hypotension (2.3; 1.3 to 4.7), blood transfusion (4.8; 2.5 to 9.3), prolonged ventilation (4.8; 2.5 to 9.0), pneumothorax (3.5; 1.6 to 7.6), sepsis (3.6; 1.8 to 7.4), hyponatraemia (7.9; 2.1 to 29.6) and total parenteral nutrition (5.5; 2.8 to 10.5). Seizures were associated with an increased risk of cerebral palsy (10.0; 4.1 to 24.7), as were parenchymal damage (32; 12.4 to 84.4) and appreciable ventricular dilatation (5.4; 3.0 to 9.8) detected by cerebral ultrasound. CONCLUSION: A reduction in the rate of cerebral palsy in very preterm babies requires an integrated approach to management throughout the antenatal, intrapartum, and neonatal periods. PMID:9040385

  19. Risk Factors for Scleral Buckle Removal: A Matched, Case-Control Study

    PubMed Central

    Covert, Douglas J.; Wirostko, William J.; Han, Dennis P.; Lindgren, Kevin E.; Hammersley, Jill A.; Connor, Thomas B.; Kim, Judy E.

    2008-01-01

    Purpose To identify preoperative, perioperative, and postoperative risk factors for scleral buckle (SB) removal. Methods A retrospective, consecutive, matched, case-control study. Cases included all patients undergoing SB removal between 1988 and 2007 at a single academic center. Case patients were matched against 4 randomly selected control patients who underwent SB implantation during the same year as the case patients. Odds ratios (ORs) were calculated for each factor investigated. Results Forty cases of SB removal and 148 matched control cases were identified. Three cases of SB removal were omitted from analysis because of incomplete records. Factors associated with SB removal for any reason, according to univariate analysis, included concurrent globe-penetrating injury at the time of SB placement (OR, 24; 95% confidence interval [CI], 2.9–200), concurrent pars plana vitrectomy (PPV) (OR, 17.3; CI, 4.9–61), diabetes mellitus (DM) (OR, 7.3; CI, 1.8–30), prior long-term topical ocular therapy (OR, 4.3; CI, 1.7–11), and subsequent ocular procedures (OR, 3.4; CI, 1.5–7.5). Factors independently associated with SB removal according to multivariate analysis included concurrent globe-penetrating injury (OR, 27.3; CI, 1.7–426), concurrent PPV (OR, 11.3; CI, 2.9–45), DM (OR, 8.9; CI, 1.3–58), and subsequent ocular procedures (OR, 3.9; CI, 1.4–11). Factors that did not alter SB removal risk included patient age; sex; and type, size, or location of buckling elements used. Conclusions Awareness of these risk factors may be valuable for the surgical planning of retinal detachment repair in patients at higher risk for subsequent SB removal and for risk stratification subsequent to SB implantation. PMID:19277232

  20. Geographic Region, Weather, Pilot Age and Air Carrier Crashes: a Case-Control Study

    PubMed Central

    Li, Guohua; Pressley, Joyce C.; Qiang, Yandong; Grabowski, Jurek G.; Baker, Susan P.; Rebok, George W.

    2009-01-01

    Background Information about risk factors of aviation crashes is crucial for developing effective intervention programs. Previous studies assessing factors associated with crash risk were conducted primarily in general aviation, air taxis and commuter air carriers. Methods A matched case-control design was used to examine the associations of geographic region, basic weather condition, and pilot age with the risk of air carrier (14 CFR Part 121) crash involvement. Cases (n=373) were air carrier crashes involving aircraft made by Boeing, McDonnell Douglas, and Airbus, recorded in the National Transportation Safety Board’s aviation crash database during 1983 through 2002, and controls (n=746) were air carrier incidents involving aircraft of the same three makes selected at random from the Federal Aviation Administration’s aviation incident database. Each case was matched with two controls on the calendar year when the index crash occurred. Conditional logistic regression was used for statistical analysis. Results With adjustment for basic weather condition, pilot age, and total flight time, the risk of air carrier crashes in Alaska was more than three times the risk for other regions [adjusted odds ratio (OR) 3.18, 95% confidence interval (CI) 1.35 – 7.49]. Instrument meteorological conditions were associated with an increased risk for air carrier crashes involving pilot error (adjusted OR 2.26, 95% CI 1.15 – 4.44) and a decreased risk for air carrier crashes without pilot error (adjusted OR 0.57, 95% CI 0.40 – 0.87). Neither pilot age nor total flight time was significantly associated with the risk of air carrier crashes. Conclusions The excess risk of air carrier crashes in Alaska and the effect of adverse weather on pilot-error crashes underscore the importance of environmental hazards in flight safety. PMID:19378910

  1. Risk of Gastric Cancer by Water Source: Evidence from the Golestan Case-Control Study

    PubMed Central

    Eichelberger, Laura; Murphy, Gwen; Etemadi, Arash; Abnet, Christian C.; Islami, Farhad; Shakeri, Ramin; Malekzadeh, Reza; Dawsey, Sanford M.

    2015-01-01

    Background Gastric cancer (GC) is the world’s fifth most common cancer, and the third leading cause of cancer-related death. Over 70% of incident cases and deaths occur in developing countries. We explored whether disparities in access to improved drinking water sources were associated with GC risk in the Golestan Gastric Cancer Case Control Study. Methods and Findings 306 cases and 605 controls were matched on age, gender, and place of residence. We conducted unconditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CI), adjusted for age, gender, ethnicity, marital status, education, head of household education, place of birth and residence, homeownership, home size, wealth score, vegetable consumption, and H. pylori seropositivity. Fully-adjusted ORs were 0.23 (95% CI: 0.05–1.04) for chlorinated well water, 4.58 (95% CI: 2.07–10.16) for unchlorinated well water, 4.26 (95% CI: 1.81–10.04) for surface water, 1.11 (95% CI: 0.61–2.03) for water from cisterns, and 1.79 (95% CI: 1.20–2.69) for all unpiped sources, compared to in-home piped water. Comparing unchlorinated water to chlorinated water, we found over a two-fold increased GC risk (OR 2.37, 95% CI: 1.56–3.61). Conclusions Unpiped and unchlorinated drinking water sources, particularly wells and surface water, were significantly associated with the risk of GC. PMID:26023788

  2. Risk factors associated with sporadic salmonellosis in adults: a case-control study.

    PubMed

    Ziehm, D; Dreesman, J; Campe, A; Kreienbrock, L; Pulz, M

    2013-02-01

    In order to identify and assess recent risk factors for sporadic human infections with Salmonella enterica, we conducted a case-control study in Lower Saxony, Germany. The data collection was based on standardized telephone interviews with 1017 cases and 346 controls aged >14 years. Odds ratios were calculated in single-factor and multi-factor analyses for Salmonella cases and two different control groups, i.e. population controls and controls with rotavirus infection. Multi-factor analysis revealed associations between sporadic Salmonella infections for two exposures by both sets of controls: consumption of raw ground pork [adjusted odds ratio (aOR) 2·38, 95% confidence interval (CI) 1·27-4·44] and foreign travel (aOR 2·12, 95% CI 1·00-4·52). Other exposures included consumption of food items containing eggs (aOR 1·43, 95% CI 0·80-2·54), consumption of chicken meat (aOR 1·77, 95% CI 1·26-2·50), outdoor meals/barbecues (aOR 3·96, 95% CI 1·41-11·12) and taking gastric acidity inhibitors (aOR 2·42, 95% CI 1·19-4·92), all were significantly associated with respect to one of the two control groups. The impact of consuming food items containing eggs or chicken meat was lower than expected from the literature. This might be a consequence of Salmonella control programmes as well as increased public awareness of eggs and chicken products being a risk factor for salmonellosis. Efforts to reduce Salmonella infections due to raw pork products should be intensified.

  3. Taste loss to terbinafine: a case-control study of potential risk factors

    PubMed Central

    STRICKER, B. H. Ch.; VAN RIEMSDIJK, M. M.; STURKENBOOM, M. C. J. M.; OTTERVANGER, J. P.

    1996-01-01

    1To identify risk factors associated with taste loss to terbinafine, we performed a case-control study of 87 reports of probable terbinafine-induced taste loss and 362 controls on terbinafine without taste loss, who had filled prescriptions from the same pharmacy and GP. Data on general health, diet, alcohol, smoking, drug use and medical history were collected by means of a self-administered questionnaire. 2The mean latent period between first intake of terbinafine and taste loss was 35 days. Most patients recovered within 4 months after discontinuation. Cases were significantly older than controls. The odds ratio of taste loss in patients of 65 years and older was 4.4 in comparison with persons younger than 35 years of age (95% CI: 1.4–16.1). The risk in persons with a body mass index (BMI) below 21 kg m−2 was 4.4 times higher than in those with a BMI of more than 27 kg m−2 (95% CI: 1.6–14.2). The risk of taste loss in patients of 55 years and older with a BMI below 21 kg m−2 was 12.8 times higher than that in patients below 35 years of age (95% CI: 1.9–88.6). 3A low BMI, a history of taste loss, and ageing are risk factors for developing taste loss to terbinafine. Prescription of this drug to elderly patients with low BMI and low daily intake of nutrients requires careful follow-up. PMID:8877021

  4. Cardiovascular Risk Factors in Subclinical Hypothyroidism: A Case Control Study in Nepalese Population

    PubMed Central

    KC, Rajendra; Khatiwada, Saroj; Deo Mehta, Kishun; Pandey, Pratikshya; Lamsal, Madhab; Majhi, Shankhar

    2015-01-01

    Objectives. To assess cardiovascular risk factors in Nepalese population with subclinical hypothyroidism as compared to age and sex matched controls. Materials and Methods. A case control study was conducted among 200 subjects (100 subclinical hypothyroid and 100 euthyroid) at B.P. Koirala Institute of Health Sciences, Dharan, Nepal. Demographic and anthropometric variables including systolic and diastolic blood pressure (BP) were taken. Blood samples were assayed for serum free triiodothyronine (fT3), free thyroxine (fT4), thyroid stimulating hormone (TSH), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), and high sensitivity C reactive protein (hs-CRP). Results. Subclinical hypothyroid patients had significantly higher diastolic BP, total cholesterol, LDL cholesterol, and hs-CRP than controls. The odds ratio of having hypercholesterolemia (>200 mg/dL), low HDL cholesterol (<40 mg/dL), undesirable LDL-cholesterol (>100 mg/dL), high hs-CRP (>1 mg/L), and high diastolic BP (>80 mmHg) and being