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Sample records for multicenter case-control samples

  1. 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 February 24, 2012 (77 FR 11136) announcing the submission to OMB of the project titled, ``A multi-center international hospital-based case-control study of lymphoma in Asia (AsiaLymph) (NCI)'' was submitted with...

  2. 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

  3. Contraceptive Use and the Risk of Ectopic Pregnancy: A Multi-Center Case-Control Study

    PubMed Central

    Meng, Chun-Xia; Ping, Hua; Qin, Guo-Juan; Cao, Shu-Jun; Xi, Xiaowei; Zhu, Qian; Li, Xiao-Cui; Zhang, Jian

    2014-01-01

    Objective To evaluate the association between the risk of ectopic pregnancy (EP) and the use of common contraceptives during the previous and current conception/menstrual cycle. Methods A multi-center case-control study was conducted in Shanghai. Women diagnosed with EP were recruited as the case group (n = 2,411). Women with intrauterine pregnancy (IUP) (n = 2,416) and non-pregnant women (n = 2,419) were matched as controls at a ratio of 1∶1. Information regarding the previous and current use of contraceptives was collected. Multivariate logistic regression analyses were performed to calculate odds ratios (ORs) and the corresponding 95% confidential intervals (CIs). Results Previous use of intrauterine devices (IUDs) was associated with a slight risk of ectopic pregnancy (AOR1 = 1.87 [95% CI: 1.48–2.37]; AOR2 = 1.84 [1.49–2.27]), and the risk increased with the duration of previous use (P1 for trend <10−4, P2 for trend <10−4). The current use of most contraceptives reduced the risk of both unwanted IUP (condom: AOR = 0.04 [0.03–0.05]; withdrawal method: AOR = 0.10 [0.07–0.13]; calendar rhythm method: AOR = 0.54 [0.40–0.73]; oral contraceptive pills [OCPs]: AOR = 0.03 [0.02–0.08]; levonorgestrel emergency contraception [LNG-EC]: AOR = 0.22 [0.16–0.30]; IUDs: AOR = 0.01 [0.005–0.012]; tubal sterilization: AOR = 0.01 [0.001–0.022]) and unwanted EP (condom: AOR1 = 0.05 [0.04–0.06]; withdrawal method: AOR1 = 0.13 [0.09–0.19]; calendar rhythm method: AOR1 = 0.66 [0.48–0.91]; OCPs: AOR1 = 0.14 [0.07–0.26]; IUDs: AOR1 = 0.17 [0.13–0.22]; tubal sterilization: AOR1 = 0.04 [0.02–0.08]). However, when contraception failed and pregnancy occurred, current use of OCPs (AOR2 = 4.06 [1.64–10.07]), LNG-EC (AOR2 = 4.87 [3.88–6.10]), IUDs (AOR2 = 21.08 [13.44–33.07]), and tubal sterilization (AOR2 = 7.68 [1.69–34.80]) increased the risk of EP compared

  4. A multicenter case-control study in Italy on hematolymphopoietic neoplasms and occupation.

    PubMed

    Costantini, A S; Miligi, L; Kriebel, D; Ramazzotti, V; Rodella, S; Scarpi, E; Stagnaro, E; Tumino, R; Fontana, A; Masala, G; Viganò, C; Vindigni, C; Crosignani, P; Benvenuti, A; Vineis, P

    2001-01-01

    We conducted a population-based, case-control study on hematolymphopoietic malignancies in 12 areas in Italy to investigate associations between different hematolymphopoietic malignancies and exposure to solvents and pesticides. We collected all incident cases 20-74 years of age from 12 areas, with a combined population of approximately 7 million residents. The control group was formed by a random sample of the study population. Data presented in this paper refer to 2,737 interviewed cases of 3,357 eligible cases and to 1,779 of 2,391 eligible controls. We analyzed risks associated with occupation using job-title information to evaluate disease pattern according to job category. An earlier publication presented results for women; here, we report the findings for men and discuss the overall patterns in both genders. The most consistent overall finding was an approximate doubling in relative risk for all four types of malignancies among male managers and related occupations. Several additional occupations were associated with elevated risk of one or more malignancies among men. These included cooks, waiters, and bartenders, and building caretakers and cleaners, for non-Hodgkin's lymphoma; textile workers and machinery fitters for Hodgkin's lymphoma; metal processors, material handlers, rubber workers, and painters for leukemia; and hairdressers, metal processors, tailors, electrical workers, and plumbers for multiple myeloma. The finding of increased risk of non-Hodgkin's lymphoma among both male and female cooks, waiters, and bartenders has not been previously reported; nor has the elevated risk of leukemia among material handlers. Among people engaged in agriculture, those employed as tractor drivers and as "orchard, vineyard, and related tree and shrub workers" appeared to be at increased risk for hematolymphopoietic malignancies. PMID:11138825

  5. Occupation and skin cancer: the results of the HELIOS-I multicenter case-control study

    PubMed Central

    Suárez, Berta; López-Abente, Gonzalo; Martínez, Carmen; Navarro, Carmen; Tormo, Maria José; Rosso, Stefano; Schraub, Simon; Gafà, Lorenzo; Sancho-Garnier, Hélène; Wechsler, Janine; Zanetti, Roberto

    2007-01-01

    Background Non-melanoma skin cancer (NMSC) is the most frequent tumour among Caucasian populations worldwide. Among the risk factors associated with this tumour, there are host-related factors and several environmental agents. A greater likelihood of high exposure to physical agents (with the exception of solar radiation) and chemical agents depends on the work setting. Our objective is to evaluate the role of occupational exposures in NMSC, with special emphasis on risk factors other than solar radiation and skin type. Methods We analysed 1585 cases (1333 basal cell carcinoma (BCC) and 183 squamous cell carcinoma (SCC)) and 1507 controls drawn from the Helios-I multicenter study. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression mixed models. Results For NMSC as a whole (both histological types), miners and quarrymen, secondary education teachers, and masons registered excess risk, regardless of exposure to solar radiation and skin type (OR 7.04, 95% CI 2.44–20.31; OR 1.75, 95% CI 1.05–2.89 and OR 1.54, 95% CI 1.04–2.27, respectively). Frequency of BCC proved higher among railway engine drivers and firemen (OR 4.55; 95% CI 0.96–21.57), specialised farmers (OR 1.65; 95% CI 1.05–2.59) and salesmen (OR 3.02; 95% CI 1.05–2.86), in addition to miners and quarrymen and secondary education teachers (OR 7.96; 95% CI 2.72–23.23 and OR 1.76; 95% CI 1.05–2.94 respectively). The occupations that registered a higher risk of SCC (though not of BCC) were those involving direct contact with livestock, construction workers not elsewhere classified (OR 2.95, 95% CI 1.12–7.74), stationary engine and related equipment operators not elsewhere classified (OR 5.31, 95% CI 1.13–21.04) and masons (OR 2.55, 95% CI 1.36–4.78). Conclusion Exposure to hazardous air pollutants, arsenic, ionizing radiations and burns may explain a good part of the associations observed in this study. The Helios study affords an excellent

  6. Risk Factors for Pancreatic Cancer in China: A Multicenter Case-Control Study

    PubMed Central

    Zheng, Zhaoxu; Zheng, Rongshou; He, Yutong; Sun, Xibin; Wang, Ning; Chen, Tianhui; Chen, Wanqing

    2016-01-01

    Background Despite having one of the highest mortality rates of all cancers, the risk factors of pancreatic cancer remain unclear. We assessed risk factors of pancreatic cancer in China. Methods A case-control study design was conducted using data from four hospital-based cancer registries (Henan Provincial Cancer Hospital, Beijing Cancer Hospital, Hebei Provincial Cancer Hospital, and Cancer Hospital of Chinese Academy of Medical Sciences). Controls were equally matched and selected from family members of non-pancreatic cancer patients in the same hospitals. Face-to-face interviews were conducted by trained staff using questionnaires. Conditional logistic regression models were used to assess odd ratios (ORs) and 95% confident intervals (CIs). Results Among 646 recruited participants, 323 were pancreatic cancer patients and 323 were controls. Multivariate logistic analysis suggested that pancreatic cancer family history (adjusted OR 1.23; 95% CI, 1.11–3.70), obesity (adjusted OR 1.77; 95% CI, 1.22–2.57), diabetes (adjusted OR 2.96; 95% CI, 1.48–5.92) and smoking (adjusted OR 1.78; 95% CI, 1.02–3.10) were risk factors for pancreatic cancer, but that drinking tea (adjusted OR 0.49; 95% CI, 0.25–0.84) was associated with reduced risk of pancreatic cancer. Conclusions Cigarette smoking, family history, obesity, and diabetes are risk factors of pancreatic cancer, which is important information for designing early intervention and preventive strategies for pancreatic cancer and may be beneficial to pancreatic cancer control in China. PMID:26441209

  7. Dietary risk factors in intestinal and diffuse types of stomach cancer: a multicenter case-control study in Poland.

    PubMed

    Boeing, H; Jedrychowski, W; Wahrendorf, J; Popiela, T; Tobiasz-Adamczyk, B; Kulig, A

    1991-07-01

    A hospital-based, multicenter, case-control study has been performed in Poland covering 741 incident stomach-cancer cases (520 males and 221 females) and the same number of controls. All stomach-cancer diagnoses were evaluated for histologic type according to the Lauren criteria. Fifty-one percent were of the intestinal type, 35 percent of the diffuse type, and 8.5 percent of the mixed type. The frequency of consumption of individual food items and several food groups was analyzed and the association of various foods with stomach cancer risk was evaluated after controlling for sex, age, occupation, education, and residency. Increased consumption of sausages was related significantly to gastric cancer risk, whereas increased consumption of cheese products, nonwhite bread, vegetables, and fruit was associated with decreased risk. A particularly strong decrease in risk was associated with consumption of radishes and onions. When consumption of fruits and vegetables, sausages, nonwhite bread, and cheese were introduced simultaneously in a multivariate model, independent effects were found only for fruit and vegetables, sausages, and nonwhite bread. The use of table salt, the frequency of eating hot meals, and an irregular eating pattern were also associated with increased risk, while additional consumption of fruit between meals showed reduced risk. If a reduction in vegetable and fruit consumption took place after marriage, an increased risk for stomach cancer was found, whereas augmented consumption of these food items after marriage decreased the risk. Separate risk models were calculated for stomach cancer of the intestinal and diffuse types, but both histologic varieties showed the same pattern of associations with dietary risk factors. PMID:1873452

  8. Acute Middle Gastrointestinal Bleeding Risk Associated with NSAIDs, Antithrombotic Drugs, and PPIs: A Multicenter Case-Control Study

    PubMed Central

    Nagata, Naoyoshi; Niikura, Ryota; Yamada, Atsuo; Sakurai, Toshiyuki; Shimbo, Takuro; Kobayashi, Yuka; Okamoto, Makoto; Mitsuno, Yuzo; Ogura, Keiji; Hirata, Yoshihiro; Fujimoto, Kazuma; Akiyama, Junichi; Uemura, Naomi; Koike, Kazuhiko

    2016-01-01

    Background Middle gastrointestinal bleeding (MGIB) risk has not been fully investigated due to its extremely rare occurrence and the need for multiple endoscopies to exclude upper and lower gastrointestinal bleeding. This study investigated whether MGIB is associated with the use of non-steroidal anti-inflammatory drugs (NSAIDs), low-dose aspirin (LDA), thienopyridines, anticoagulants, and proton-pump inhibitors (PPIs), and whether PPI use affects the interactions between MGIB and antithrombotic drugs. Methods In this multicenter, hospital-based, case-control study, 400 patients underwent upper and lower endoscopy, 80 had acute overt MGIB and 320 had no bleeding and were matched for age and sex as controls (1:4). MGIB was additionally evaluated by capsule and/or double-balloon endoscopy, after excluding upper and lower GI bleeding. Adjusted odds ratios (AOR) for MGIB risk were calculated using conditional logistic regression. To estimate the propensity score, we employed a logistic regression model for PPI use. Results In patients with MGIB, mean hemoglobin level was 9.4 g/dL, and 28 patients (35%) received blood transfusions. Factors significantly associated with MGIB were chronic kidney disease (p<0.001), liver cirrhosis (p = 0.034), NSAIDs (p<0.001), thienopyridines (p<0.001), anticoagulants (p = 0.002), and PPIs (p<0.001). After adjusting for these factors, NSAIDs (AOR, 2.5; p = 0.018), thienopyridines (AOR, 3.2; p = 0.015), anticoagulants (AOR, 4.3; p = 0.028), and PPIs (AOR; 2.0; p = 0.021) were independently associated with MGIB. After adjusting for propensity score, the use of PPIs remained an independent risk factors for MGIB (AOR, 1.94; p = 0.034). No significant interactions were observed between PPIs and NSAIDs (AOR, 0.7; p = 0.637), LDA (AOR, 0.3; p = 0.112), thienopyridine (AOR, 0.7, p = 0.671), or anticoagulants (AOR, 0.5; p = 0.545). Conclusions One-third of patients with acute small intestinal bleeding required blood transfusion. NSAIDs

  9. Investigation of occupational and environmental causes of respiratory cancers (ICARE): a multicenter, population-based case-control study in France

    PubMed Central

    2011-01-01

    Background Occupational causes of respiratory cancers need to be further investigated: the role of occupational exposures in the aetiology of head and neck cancers remains largely unknown, and there are still substantial uncertainties for a number of suspected lung carcinogens. The main objective of the study is to examine occupational risk factors for lung and head and neck cancers. Methods/design ICARE is a multi-center, population-based case-control study, which included a group of 2926 lung cancer cases, a group of 2415 head and neck cancer cases, and a common control group of 3555 subjects. Incident cases were identified in collaboration with cancer registries, in 10 geographical areas. The control group was a random sample of the population of these areas, with a distribution by sex and age comparable to that of the cases, and a distribution by socioeconomic status comparable to that of the population. Subjects were interviewed face to face, using a standardized questionnaire collecting particularly information on tobacco and alcohol consumption, residential history and a detailed description of occupational history. Biological samples were also collected from study subjects. The main occupational exposures of interest are asbestos, man-made mineral fibers, formaldehyde, polycyclic aromatic hydrocarbons, chromium and nickel compounds, arsenic, wood dust, textile dust, solvents, strong acids, cutting fluids, silica, diesel fumes, welding fumes. The complete list of exposures of interest includes more than 60 substances. Occupational exposure assessment will use several complementary methods: case-by-case evaluation of exposure by experts; development and use of algorithms to assess exposure from the questionnaires; application of job-exposure matrices. Discussion The large number of subjects should allow to uncover exposures associated with moderate increase in risks, and to evaluate risks associated with infrequent or widely dispersed exposures. It will be

  10. LOCAL CASE-CONTROL SAMPLING: EFFICIENT SUBSAMPLING IN IMBALANCED DATA SETS

    PubMed Central

    Fithian, William; Hastie, Trevor

    2014-01-01

    For classification problems with significant class imbalance, subsampling can reduce computational costs at the price of inflated variance in estimating model parameters. We propose a method for subsampling efficiently for logistic regression by adjusting the class balance locally in feature space via an accept–reject scheme. Our method generalizes standard case-control sampling, using a pilot estimate to preferentially select examples whose responses are conditionally rare given their features. The biased subsampling is corrected by a post-hoc analytic adjustment to the parameters. The method is simple and requires one parallelizable scan over the full data set. Standard case-control sampling is inconsistent under model misspecification for the population risk-minimizing coefficients θ*. By contrast, our estimator is consistent for θ* provided that the pilot estimate is. Moreover, under correct specification and with a consistent, independent pilot estimate, our estimator has exactly twice the asymptotic variance of the full-sample MLE—even if the selected subsample comprises a miniscule fraction of the full data set, as happens when the original data are severely imbalanced. The factor of two improves to 1+1c if we multiply the baseline acceptance probabilities by c > 1 (and weight points with acceptance probability greater than 1), taking roughly 1+c2 times as many data points into the subsample. Experiments on simulated and real data show that our method can substantially outperform standard case-control subsampling. PMID:25492979

  11. Association between levonorgestrel emergency contraception and the risk of ectopic pregnancy: a multicenter case-control study.

    PubMed

    Zhang, Jian; Li, Cheng; Zhao, Wei-Hong; Xi, Xiaowei; Cao, Shu-Jun; Ping, Hua; Qin, Guo-Juan; Cheng, Linan; Huang, He-Feng

    2015-01-01

    Cases of ectopic pregnancy (EP) following levonorgestrel emergency contraception (LNG-EC) failure have been reported continuously, but whether there is an association between EP risk and LNG-EC is unclear. We concluded a case-control study to explore this association by recruiting 2,411 EP patients as case group, and 2,416 women with intrauterine pregnancy and 2,419 non-pregnant women as control groups. Odds ratios (ORs) and their 95% confidential intervals (CIs) were calculated and adjusted for potential confounding factors. Previous use of LNG-EC was not correlated with the EP. Compared to women who did not use contraceptives, current use of LNG-EC reduced the risk for intrauterine pregnancy (Adjusted OR [AOR] = 0.20, 95%CI: 0.14-0.27), but did not increase the risk for EP (AOR2 = 1.04, 95%CI: 0.76-1.42). Furthermore, compared to women who did not have further act of intercourse, women with unprotected further act of intercourse were at a higher risk of EP (AOR1 = 2.35, 95%CI: 1.17-4.71), and women with repeated use of LNG-EC for further intercourse during the same cycle was also associated with a higher risk for EP (AOR1 = 3.08, 95%CI: 1.09-8.71; AOR2 = 2.49, 95%CI: 1.00-6.19). A better understanding of the risk of EP following LNG-EC failure can optimize LNG-EC use and thus reduce the risk of EP. PMID:25674909

  12. Risk factors, clinical features and outcomes of visceral leishmaniasis in solid-organ transplant recipients: a retrospective multicenter case-control study.

    PubMed

    Clemente, W; Vidal, E; Girão, E; Ramos, A S D; Govedic, F; Merino, E; Muñoz, P; Sabé, N; Cervera, C; Cota, G F; Cordero, E; Mena, A; Montejo, M; López-Medrano, F; Aguado, J M; Fernandes, P; Valerio, M; Carratalá, J; Moreno, A; Oliveira, J; Mourão, P H O; Torre-Cisneros, J

    2015-01-01

    Visceral leishmaniasis (VL) is a rare disease in solid-organ transplant (SOT) recipients. Therefore, little is known about the risk factors and disease behavior in the transplant setting. This multicenter, matched case-control study (1:2 ratio) was designed to determine the risk factors, clinical features and outcomes of VL among this population. Control and case subjects were matched by center, transplant type and timing. Thirty-six VL cases were identified among 25 139 SOT recipients (0.1%). VL occurred 5.7-fold more frequently in Brazil than in Spain, presenting a median time of 11 months after transplantation. High-dose prednisone in the preceding 6 months was associated with VL. Patients were diagnosed over 1 month after symptom onset in 25% of cases. Thirty-one patients (86%) were febrile upon diagnosis, 81% exhibited visceromegaly and 47% showed pancytopenia. Concomitant infection was common. Parasites were identified in 89% of patients; the remaining patients were diagnosed by serology. The majority of the patients received amphotericin B. Relapses occurred in 25.7% of cases, and the crude mortality rate was 2.8%. VL after SOT is related to the VL prevalence in the general population. Delayed diagnosis frequently occurs. Liposomal amphotericin is the most commonly used therapy; mortality is low, although relapses are common. PMID:25636932

  13. The Global Enteric Multicenter Study (GEMS) of Diarrheal Disease in Infants and Young Children in Developing Countries: Epidemiologic and Clinical Methods of the Case/Control Study

    PubMed Central

    Kotloff, Karen L.; Blackwelder, William C.; Nasrin, Dilruba; Nataro, James P.; Farag, Tamer H.; van Eijk, Annemieke; Adegbola, Richard A.; Alonso, Pedro L.; Breiman, Robert F.; Golam Faruque, Abu Syed; Saha, Debasish; Sow, Samba O.; Sur, Dipika; Zaidi, Anita K. M.; Biswas, Kousick; Panchalingam, Sandra; Clemens, John D.; Cohen, Dani; Glass, Roger I.; Mintz, Eric D.; Sommerfelt, Halvor; Levine, Myron M.

    2012-01-01

    Background. Diarrhea is a leading cause of illness and death among children aged <5 years in developing countries. This paper describes the clinical and epidemiological methods used to conduct the Global Enteric Multicenter Study (GEMS), a 3-year, prospective, age-stratified, case/control study to estimate the population-based burden, microbiologic etiology, and adverse clinical consequences of acute moderate-to-severe diarrhea (MSD) among a censused population of children aged 0–59 months seeking care at health centers in sub-Saharan Africa and South Asia. Methods. GEMS was conducted at 7 field sites, each serving a population whose demography and healthcare utilization practices for childhood diarrhea were documented. We aimed to enroll 220 MSD cases per year from selected health centers serving each site in each of 3 age strata (0–11, 12–23, and 24–59 months), along with 1–3 matched community controls. Cases and controls supplied clinical, epidemiologic, and anthropometric data at enrollment and again approximately 60 days later, and provided enrollment stool specimens for identification and characterization of potential diarrheal pathogens. Verbal autopsy was performed if a child died. Analytic strategies will calculate the fraction of MSD attributable to each pathogen and the incidence, financial costs, nutritional consequences, and case fatality overall and by pathogen. Conclusions. When completed, GEMS will provide estimates of the incidence, etiology, and outcomes of MSD among infants and young children in sub-Saharan Africa and South Asia. This information can guide development and implementation of public health interventions to diminish morbidity and mortality from diarrheal diseases. PMID:23169936

  14. Evaluation of oxidant-antioxidant status in tissue samples in oral cancer: A case control study

    PubMed Central

    Srivastava, Kumar Chandan; Austin, Ravi David; Shrivastava, Deepti

    2016-01-01

    Background: Imbalances between the oxidant-antioxidant status have been implicated in the pathogenesis of several diseases, including cancer. The aim of this study was to evaluate the extent of lipid peroxidation and antioxidants in the tissue samples of oral squamous cell carcinoma (OSCC) patients of different clinical stages in comparison with the healthy controls. Materials and Methods: A case-control study was designed with 20 new histopathologically proven oral carcinoma patients and an equal number of age, sex, and tobacco chewing habit matched healthy subjects. Their tissue samples were subjected to evaluation of lipid peroxidation product and antioxidant enzymes, namely, superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), and glutathione peroxidase (GPx) using spectrophotometric methods. The data are expressed as mean ± standard deviation. The statistical comparisons between the study groups were performed by independent Student's unpaired t-test and one-way analysis of variance. Post-hoc analysis was performed for within study group comparisons. Karl Pearson correlation was performed for the biochemical parameters within the group and between the groups. For statistically significant correlations, simple linear regression was performed using SPSS (α=0.05). Results: Significant reduction in lipid peroxidation (P < 0.001) SOD and CAT (P < 0.001) was observed in the tissue of OSCC patients as compared with the healthy controls. On the other hand, reduced GSH and GPx were significantly increased in tumor samples. Conclusion: Reduced lipid peroxidation and increased activity of reduced GSH and GPx provides the suitable environment for the local growth and invasion of the tumor and metastasis in the later stages. Among the antioxidant enzymes, GSH reductase appears to have a profound role in carcinogenesis and thus it can be considered as potential prognostic marker. PMID:27076834

  15. Two-stage case-control studies: precision of parameter estimates and considerations in selecting sample size.

    PubMed

    Hanley, James A; Csizmadi, Ilona; Collet, Jean-Paul

    2005-12-15

    A two-stage case-control design, in which exposure and outcome are determined for a large sample but covariates are measured on only a subsample, may be much less expensive than a one-stage design of comparable power. However, the methods available to plan the sizes of the stage 1 and stage 2 samples, or to project the precision/power provided by a given configuration, are limited to the case of a binary exposure and a single binary confounder. The authors propose a rearrangement of the components in the variance of the estimator of the log-odds ratio. This formulation makes it possible to plan sample sizes/precision by including variance inflation factors to deal with several confounding factors. A practical variance bound is derived for two-stage case-control studies, where confounding variables are binary, while an empirical investigation is used to anticipate the additional sample size requirements when these variables are quantitative. Two methods are suggested for sample size planning based on a quantitative, rather than binary, exposure. PMID:16269581

  16. Risk factors for bloodstream infections due to colistin-resistant KPC-producing Klebsiella pneumoniae: results from a multicenter case-control-control study.

    PubMed

    Giacobbe, D R; Del Bono, V; Trecarichi, E M; De Rosa, F G; Giannella, M; Bassetti, M; Bartoloni, A; Losito, A R; Corcione, S; Bartoletti, M; Mantengoli, E; Saffioti, C; Pagani, N; Tedeschi, S; Spanu, T; Rossolini, G M; Marchese, A; Ambretti, S; Cauda, R; Viale, P; Viscoli, C; Tumbarello, M

    2015-12-01

    The increasing prevalence of colistin resistance (ColR) Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (Kp) is a matter of concern because of its unfavourable impact on mortality of KPC-Kp bloodstream infections (BSI) and the shortage of alternative therapeutic options. A matched case-control-control analysis was conducted. The primary study end point was to assess risk factors for ColR KPC-Kp BSI. The secondary end point was to describe mortality and clinical characteristics of these infections. To assess risk factors for ColR, 142 patients with ColR KPC-Kp BSI were compared to two controls groups: 284 controls without infections caused by KPC-Kp (control group A) and 284 controls with colistin-susceptible (ColS) KPC-Kp BSI (control group B). In the first multivariate analysis (cases vs. group A), previous colistin therapy, previous KPC-Kp colonization, ≥3 previous hospitalizations, Charlson score ≥3 and neutropenia were found to be associated with the development of ColR KPC-Kp BSI. In the second multivariate analysis (cases vs. group B), only previous colistin therapy, previous KPC-Kp colonization and Charlson score ≥3 were associated with ColR. Overall, ColR among KPC-Kp blood isolates increased more than threefold during the 4.5-year study period, and 30-day mortality of ColR KPC-Kp BSI was as high as 51%. Strict rules for the use of colistin are mandatory to staunch the dissemination of ColR in KPC-Kp-endemic hospitals. PMID:26278669

  17. Risk Factors for Human Immunodeficiency Virus Infection among Brazilian Blood Donors; a Multicenter Case-Control Study Using Audio Computer-Assisted Structured-Interviews

    PubMed Central

    de Almeida-Neto, Cesar; Goncalez, Thelma T.; Birch, Rebecca Jeffries; de Carvalho, Silvia Maia F.; Capuani, Ligia; Leão, Silvana Carneiro; Miranda, Carolina; Rocha, Pedro Capuani; Carneiro-Proietti, Anna Barbara; Johnson, Bryce R.; Wright, David J.; Murphy, Edward L.; Custer, Brian

    2013-01-01

    Background Although risk factors for HIV infection are known, it is important for blood centers to understand local epidemiology and disease transmission patterns. Current risk factors for HIV infection in blood donors in Brazil were assessed. Methods A case-control study was conducted at large public blood centers located in four major cities between April 2009 – March 2011. Cases were persons whose donations were confirmed positive by enzyme immunoassays followed by Western Blot confirmation. Audio computer-assisted structured-interviews (ACASI) were completed by all cases and controls. Multivariable logistic regression was used to estimate adjusted odds ratios (AORs) and associated 95% confidence intervals (CIs). Results There were 341 cases, including 47 with recently-acquired infection, and 791 controls. Disclosed risk factors for both females and males were sex with an HIV-positive person (adjusted odds ratio (AOR) 11.3, 95% CI [4.1, 31.7]) and being an IVDU or sexual partner of an IVDU (AOR 4.65 [1.8, 11.7]). For female blood donors, additional risk factors were having male sex partners who also are MSM (AOR 13.5 [3.1, 59.8]), and having unprotected sex with multiple sexual partners (AOR 5.19 [2.1, 12.9]). The primary risk factor for male blood donors was MSM activity (AOR 21.6 [8.8, 52.9.]). Behaviors associated with recently-acquired HIV were being a MSM or sex partner of MSM (13.82, [4.7, 40.3]), and IVDU (11.47, [3.0, 43.2]). Conclusion Risk factors in blood donors parallel those in the general population in Brazil. Identified risk factors suggest that donor compliance with selection procedures at the participating blood centers is inadequate. PMID:23517235

  18. Clinical utility of simultaneous measurement of alpha-fetoprotein and des-γ-carboxy prothrombin for diagnosis of patients with hepatocellular carcinoma in China: A multi-center case-controlled study of 1,153 subjects.

    PubMed

    Song, Peipei; Feng, Xiaobin; Inagaki, Yoshinori; Song, Tianqiang; Zhang, Keming; Wang, Zhigang; Zheng, Shuguo; Ma, Kuansheng; Li, Qiang; Kong, Dalu; Wu, Qiang; Zhang, Ti; Zhao, Xin; Hasegawa, Kiyoshi; Sugawara, Yasuhiko; Kokudo, Norihiro; Tang, Wei

    2014-10-01

    This study aimed to investigate the clinical utility of simultaneous measurement of alphafetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) for hepatocellular carcinoma (HCC) diagnosis in Chinese patients predominantly caused by hepatitis B virus infection by a multi-center case-controlled study. Subjects were 1,153 individuals from three major hospitals in China, including 550 cases in HCC group, 164 in Malignant disease group, 182 in Benign disease group, 85 in Chronic liver disease group, and 173 in Normal group. Serum levels of AFP and DCP were measured and clinicopathological features were determined for all subjects. Results showed that the levels of DCP and AFP were significantly higher in HCC group (550 patients, 74.18% with HBV infection) than that in other four groups (P < 0.001). Receiver operating curves (ROC) indicated the optimal cut-off value was 86 mAU/mL for DCP with a sensitivity of 71.50% and specificity of 86.30%, and 21 ng/mL for AFP with a sensitivity of 68.00% and specificity of 93.20%. The area under ROC curve was 0.846 for DCP, 0.832 for AFP, and 0.890 for the combination of DCP and AFP. The combination of DCP and AFP resulted in a higher Youden index and a sensitivity of approximately 90%, even for small tumors. The simultaneous measurement of AFP and DCP could achieve a better sensitivity in diagnosing Chinese HCC patients, even for small tumors. PMID:25382443

  19. Sanitation and Hygiene-Specific Risk Factors for Moderate-to-Severe Diarrhea in Young Children in the Global Enteric Multicenter Study, 2007–2011: Case-Control Study

    PubMed Central

    O’Reilly, Ciara E.; Levine, Myron M.; Kotloff, Karen L.; Farag, Tamer H.; Nasrin, Dilruba; Alonso, Pedro L.; Breiman, Robert F.; Omore, Richard; Faruque, Abu S. G.; Das, Sumon Kumar; Ahmed, Shahnawaz; Saha, Debasish; Sow, Samba O.; Sur, Dipika; Zaidi, Anita K. M.; Quadri, Fahreen; Mintz, Eric D.

    2016-01-01

    Background Diarrheal disease is the second leading cause of disease in children less than 5 y of age. Poor water, sanitation, and hygiene conditions are the primary routes of exposure and infection. Sanitation and hygiene interventions are estimated to generate a 36% and 48% reduction in diarrheal risk in young children, respectively. Little is known about whether the number of households sharing a sanitation facility affects a child's risk of diarrhea. The objective of this study was to describe sanitation and hygiene access across the Global Enteric Multicenter Study (GEMS) sites in Africa and South Asia and to assess sanitation and hygiene exposures, including shared sanitation access, as risk factors for moderate-to-severe diarrhea (MSD) in children less than 5 y of age. Methods/Findings The GEMS matched case-control study was conducted between December 1, 2007, and March 3, 2011, at seven sites in Basse, The Gambia; Nyanza Province, Kenya; Bamako, Mali; Manhiça, Mozambique; Mirzapur, Bangladesh; Kolkata, India; and Karachi, Pakistan. Data was collected for 8,592 case children aged <5 y old experiencing MSD and for 12,390 asymptomatic age, gender, and neighborhood-matched controls. An MSD case was defined as a child with a diarrheal illness <7 d duration comprising ≥3 loose stools in 24 h and ≥1 of the following: sunken eyes, skin tenting, dysentery, intravenous (IV) rehydration, or hospitalization. Site-specific conditional logistic regression models were used to explore the association between sanitation and hygiene exposures and MSD. Most households at six sites (>93%) had access to a sanitation facility, while 70% of households in rural Kenya had access to a facility. Practicing open defecation was a risk factor for MSD in children <5 y old in Kenya. Sharing sanitation facilities with 1–2 or ≥3 other households was a statistically significant risk factor for MSD in Kenya, Mali, Mozambique, and Pakistan. Among those with a designated handwashing

  20. Relative Quantification and Higher-Order Modeling of the Plasma Glycan Cancer Burden Ratio in Ovarian Cancer Case-Control Samples

    PubMed Central

    Hecht, Elizabeth S.; Scholl, Elizabeth H.; Walker, S. Hunter; Taylor, Amber D.; Cliby, William A.; Motsinger-Reif, Alison A.; Muddiman, David C.

    2016-01-01

    An early-stage, population-wide biomarker for ovarian cancer (OVC) is essential to reverse its high mortality rate. Aberrant glycosylation by OVC has been reported, but studies have yet to identify an N-glycan with sufficiently high specificity. We curated a human biorepository of 82 case-control plasma samples, with 27%, 12%, 46%, and 15% falling across stages I–IV, respectively. For relatve quantitation, glycans were analyzed by the individuality normalization when labeling with glycan hydrazide tags (INLIGHT) strategy for enhanced electrospray ionization, MS/MS analysis. Sixty-three glycan cancer burden ratios (GBRs), defined as the log10 ratio of the case-control extracted ion chromatogram abundances, were calculated above the limit of detection. The final GBR models, built using stepwise forward regression, included three significant terms: OVC stage, normalized mean GBR, and tag chemical purity; glycan class, fucosylation, or sialylation were not significant variables. After Bonferroni correction, seven N-glycans were identified as significant (p < 0.05), and after false discovery rate correction, an additional four glycans were determined to be significant (p < 0.05), with one borderline (p = 0.05). For all N-glycans, the vectors of the effects from stages II–IV were sequentially reversed, suggesting potential biological changes in OVC morphology or in host response. PMID:26347193

  1. Blinded, multi-center validation of EEG and rating scales in identifying ADHD within a clinical sample.

    PubMed

    Snyder, Steven M; Quintana, Humberto; Sexson, Sandra B; Knott, Peter; Haque, A F M; Reynolds, Donald A

    2008-06-30

    Previous validation studies of attention deficit/hyperactivity disorder (ADHD) assessment by rating scales or EEG have provided Class-IV evidence per standards of the American Academy of Neurology. To investigate clinical applications, we collected Class-I evidence, namely from a blinded, prospective, multi-center study of a representative clinical sample categorized with a clinical standard. Participating males (101) and females (58) aged 6 to 18 had presented to one of four psychiatric and pediatric clinics because of the suspected presence of attention and behavior problems. DSM-IV diagnosis was performed by clinicians assisted with a semi-structured clinical interview. EEG (theta/beta ratio) and ratings scales (Conners Rating Scales-Revised and ADHD Rating Scales-IV) were collected separately in a blinded protocol. ADHD prevalence in the clinical sample was 61%, whereas the remainder had other childhood/adolescent disorders or no diagnosis. Comorbidities were observed in 66% of ADHD patients and included mood, anxiety, disruptive, and learning disorders at rates similar to previous findings. EEG identified ADHD with 87% sensitivity and 94% specificity. Rating scales provided sensitivity of 38-79% and specificity of 13-61%. While parent or teacher identification of ADHD by rating scales was reduced in accuracy when applied to a diverse clinical sample, theta/beta ratio changes remained consistent with the clinician's ADHD diagnosis. Because theta/beta ratio changes do not identify comorbidities or alternative diagnoses, the results do not support the use of EEG as a stand-alone diagnostic and should be limited to the interpretation that EEG may complement a clinical evaluation for ADHD. PMID:18423617

  2. Differences in fungi present in induced sputum samples from asthma patients and non-atopic controls: a community based case control study

    PubMed Central

    2013-01-01

    Background There is emerging evidence for the presence of an extensive microbiota in human lungs. It is not known whether variations in the prevalence of species of microbiota in the lungs may have aetiological significance in respiratory conditions such as asthma. The aim of the study was to undertake semi-quantitative analysis of the differences in fungal species in pooled sputum samples from asthma patients and controls. Methods Induced sputum samples were collected in a case control study of asthma patients and control subjects drawn from the community in Wandsworth, London. Samples from both groups were pooled and then tested for eukaryotes. DNA was amplified using standard PCR techniques, followed by pyrosequencing and comparison of reads to databases of known sequences to determine in a semi-quantitative way the percentage of DNA from known species in each of the two pooled samples. Results A total of 136 fungal species were identified in the induced sputum samples, with 90 species more common in asthma patients and 46 species more common in control subjects. Psathyrella candolleana, Malassezia pachydermatis, Termitomyces clypeatus and Grifola sordulenta showed a higher percentage of reads in the sputum of asthma patients and Eremothecium sinecaudum, Systenostrema alba, Cladosporium cladosporioides and Vanderwaltozyma polyspora showed a higher percentage of reads in the sputum of control subjects. A statistically significant difference in the pattern of fungi that were present in the respective samples was demonstrated using the Phylogenetic (P) test (P < 0.0001). Conclusion This study is novel in providing evidence for the widespread nature of fungi in the sputum of healthy and asthmatic individuals. Differences in the pattern of fungi present in asthma patients and controls merit further investigation. Of particular interest was the presence of Malassezia pachydermatis, which is known to be associated with atopic dermatitis. PMID:23384395

  3. A multicenter study of viable PCR using propidium monoazide to detect Legionella in water samples.

    PubMed

    Scaturro, Maria; Fontana, Stefano; Dell'eva, Italo; Helfer, Fabrizia; Marchio, Michele; Stefanetti, Maria Vittoria; Cavallaro, Mario; Miglietta, Marilena; Montagna, Maria Teresa; De Giglio, Osvalda; Cuna, Teresa; Chetti, Leonarda; Sabattini, Maria Antonietta Bucci; Carlotti, Michela; Viggiani, Mariagabriella; Stenico, Alberta; Romanin, Elisa; Bonanni, Emma; Ottaviano, Claudio; Franzin, Laura; Avanzini, Claudio; Demarie, Valerio; Corbella, Marta; Cambieri, Patrizia; Marone, Piero; Rota, Maria Cristina; Bella, Antonino; Ricci, Maria Luisa

    2016-07-01

    Legionella quantification in environmental samples is overestimated by qPCR. Combination with a viable dye, such as Propidium monoazide (PMA), could make qPCR (named then vPCR) very reliable. In this multicentre study 717 artificial water samples, spiked with fixed concentrations of Legionella and interfering bacterial flora, were analysed by qPCR, vPCR and culture and data were compared by statistical analysis. A heat-treatment at 55 °C for 10 minutes was also performed to obtain viable and not-viable bacteria. When data of vPCR were compared with those of culture and qPCR, statistical analysis showed significant differences (P < 0.001). However, although the heat-treatment caused an abatement of CFU/mL ≤1 to 1 log10 unit, the comparison between untreated and heat-treated samples analysed by vPCR highlighted non-significant differences (P > 0.05). Overall this study provided a good experimental reproducibility of vPCR but also highlighted limits of PMA in the discriminating capability of dead and live bacteria, making vPCR not completely reliable. PMID:27133308

  4. Genomewide linkage scan of schizophrenia in a large multicenter pedigree sample using single nucleotide polymorphisms

    PubMed Central

    Holmans, PA; Riley, B; Pulver, AE; Owen, MJ; Wildenauer, DB; Gejman, PV; Mowry, BJ; Laurent, C; Kendler, KS; Nestadt, G; Williams, NM; Schwab, SG; Sanders, AR; Nertney, D; Mallet, J; Wormley, B; Lasseter, VK; O’Donovan, MC; Duan, J; Albus, M; Alexander, M; Godard, S; Ribble, R; Liang, KY; Norton, N; Maier, W; Papadimitriou, G; Walsh, D; Jay, M; O’Neill, A; Lerer, FB; Dikeos, D; Crowe, RR; Silverman, JM; Levinson, DF

    2008-01-01

    A genomewide linkage scan was carried out in eight clinical samples of informative schizophrenia families. After all quality control checks, the analysis of 707 European-ancestry families included 1,615 affected and 1,602 unaffected genotyped individuals, and the analysis of all 807 families included 1900 affected and 1839 unaffected individuals. Multipoint linkage analysis with correction for marker-marker linkage disequilibrium was carried out with 5,861 single nucleotide polymorphisms (SNPs; Illumina 4.0 linkage map). Suggestive evidence for linkage (European families) was observed on chromosomes 8p21, 8q24.1, 9q34 and 12q24.1 in non-parametric and/or parametric analyses. In a logistic regression allele-sharing analysis of linkage allowing for intersite heterogeneity, genomewide significant evidence for linkage was observed on chromosome 10p12. Significant heterogeneity was also observed on chromosome 22q11.1. Evidence for linkage across family sets and analyses was most consistent on chromosome 8p21, with a one-lod support interval that does not include the candidate gene NRG1, suggesting that one or more other susceptibility loci might exist in the region. In this era of genomewide association and deep resequencing studies, consensus linkage regions deserve continued attention, given that linkage signals can be produced by many types of genomic variation, including any combination of multiple common or rare SNPs or copy number variants in a region. PMID:19223858

  5. Application of a New Method for GWAS in a Related Case/Control Sample with Known Pedigree Structure: Identification of New Loci for Nephrolithiasis

    PubMed Central

    Tore, Silvia; Casula, Stefania; Casu, Giuseppina; Concas, Maria Pina; Pistidda, Paola; Persico, Ivana; Sassu, Alessandro; Maestrale, Giovanni Battista; Mele, Caterina; Caruso, Maria Rosa; Bonerba, Bibiana; Usai, Paolo; Deiana, Ivo; Thornton, Timothy; Pirastu, Mario; Forabosco, Paola

    2011-01-01

    In contrast to large GWA studies based on thousands of individuals and large meta-analyses combining GWAS results, we analyzed a small case/control sample for uric acid nephrolithiasis. Our cohort of closely related individuals is derived from a small, genetically isolated village in Sardinia, with well-characterized genealogical data linking the extant population up to the 16th century. It is expected that the number of risk alleles involved in complex disorders is smaller in isolated founder populations than in more diverse populations, and the power to detect association with complex traits may be increased when related, homogeneous affected individuals are selected, as they are more likely to be enriched with and share specific risk variants than are unrelated, affected individuals from the general population. When related individuals are included in an association study, correlations among relatives must be accurately taken into account to ensure validity of the results. A recently proposed association method uses an empirical genotypic covariance matrix estimated from genome-screen data to allow for additional population structure and cryptic relatedness that may not be captured by the genealogical data. We apply the method to our data, and we also investigate the properties of the method, as well as other association methods, in our highly inbred population, as previous applications were to outbred samples. The more promising regions identified in our initial study in the genetic isolate were then further investigated in an independent sample collected from the Italian population. Among the loci that showed association in this study, we observed evidence of a possible involvement of the region encompassing the gene LRRC16A, already associated to serum uric acid levels in a large meta-analysis of 14 GWAS, suggesting that this locus might lead a pathway for uric acid metabolism that may be involved in gout as well as in nephrolithiasis. PMID:21283782

  6. How Many Samples and How Many Culture Media To Diagnose a Prosthetic Joint Infection: a Clinical and Microbiological Prospective Multicenter Study

    PubMed Central

    Léger, Julie; Tandé, Didier; Plouzeau, Chloé; Valentin, Anne Sophie; Jolivet-Gougeon, Anne; Lemarié, Carole; Kempf, Marie; Héry-Arnaud, Geneviève; Bret, Laurent; Juvin, Marie Emmanuelle; Giraudeau, Bruno; Burucoa, Christophe

    2015-01-01

    Although numerous perioperative samples and culture media are required to diagnose prosthetic joint infection (PJI), their exact number and types have not yet been definitely determined with a high level of proof. We conducted a prospective multicenter study to determine the minimal number of samples and culture media required for accurate diagnosis of PJI. Over a 2-year period, consecutive patients with clinical signs suggesting PJI were included, with five perioperative samples per patient. The bacteriological and PJI diagnosis criteria were assessed using a random selection of two, three, or four samples and compared with those obtained using the recommended five samples (references guidelines). The results obtained with two or three culture media were then compared with those obtained with five culture media for both criteria. The times-to-positivity of the different culture media were calculated. PJI was confirmed in 215/264 suspected cases, with a bacteriological criterion in 192 (89%). The PJI was monomicrobial (85%) or polymicrobial (15%). Percentages of agreement of 98.1% and 99.7%, respectively, for the bacteriological criterion and confirmed PJI diagnosis were obtained when four perioperative samples were considered. The highest percentages of agreement were obtained with the association of three culture media, a blood culture bottle, a chocolate agar plate, and Schaedler broth, incubated for 5, 7, and 14 days, respectively. This new procedure leads to significant cost saving. Our prospective multicenter study showed that four samples seeded on three culture media are sufficient for diagnosing PJI. PMID:26637380

  7. How Many Samples and How Many Culture Media To Diagnose a Prosthetic Joint Infection: a Clinical and Microbiological Prospective Multicenter Study.

    PubMed

    Bémer, Pascale; Léger, Julie; Tandé, Didier; Plouzeau, Chloé; Valentin, Anne Sophie; Jolivet-Gougeon, Anne; Lemarié, Carole; Kempf, Marie; Héry-Arnaud, Geneviève; Bret, Laurent; Juvin, Marie Emmanuelle; Giraudeau, Bruno; Corvec, Stéphane; Burucoa, Christophe

    2016-02-01

    Although numerous perioperative samples and culture media are required to diagnose prosthetic joint infection (PJI), their exact number and types have not yet been definitely determined with a high level of proof. We conducted a prospective multicenter study to determine the minimal number of samples and culture media required for accurate diagnosis of PJI. Over a 2-year period, consecutive patients with clinical signs suggesting PJI were included, with five perioperative samples per patient. The bacteriological and PJI diagnosis criteria were assessed using a random selection of two, three, or four samples and compared with those obtained using the recommended five samples (references guidelines). The results obtained with two or three culture media were then compared with those obtained with five culture media for both criteria. The times-to-positivity of the different culture media were calculated. PJI was confirmed in 215/264 suspected cases, with a bacteriological criterion in 192 (89%). The PJI was monomicrobial (85%) or polymicrobial (15%). Percentages of agreement of 98.1% and 99.7%, respectively, for the bacteriological criterion and confirmed PJI diagnosis were obtained when four perioperative samples were considered. The highest percentages of agreement were obtained with the association of three culture media, a blood culture bottle, a chocolate agar plate, and Schaedler broth, incubated for 5, 7, and 14 days, respectively. This new procedure leads to significant cost saving. Our prospective multicenter study showed that four samples seeded on three culture media are sufficient for diagnosing PJI. PMID:26637380

  8. Evidence for schizophrenia susceptibility alleles in the Indian population: An association of neurodevelopmental genes in case-control and familial samples.

    PubMed

    Jajodia, Ajay; Kaur, Harpreet; Kumari, Kalpana; Gupta, Meenal; Baghel, Ruchi; Srivastava, Ankit; Sood, Mamta; Chadda, Rakesh Kumar; Jain, Sanjeev; Kukreti, Ritushree

    2015-03-01

    Schizophrenia is a severe psychiatric disorder with lifetime prevalence of ~1% worldwide. A genotyping study was conducted using a custom panel of Illumina 1536 SNPs in 840 schizophrenia cases and 876 controls (351 patients and 385 controls from North India; and 436 patients, 401 controls and 143 familial samples with 53 probands containing 37 complete and 16 incomplete trios from South India). Meta-analysis of this population of Indo-European and Dravidian ancestry identified three strongly associated variants with schizophrenia: STT3A (rs548181, p=1.47×10(-5)), NRG1 (rs17603876, p=8.66×10(-5)) and GRM7 (rs3864075, p=4.06×10(-3)). Finally, a meta-analysis was conducted comparing our data with data from the Schizophrenia Psychiatric Genome-Wide Association Study Consortium (PGC-SCZ) that supported rs548181 (p=1.39×10(-7)). In addition, combined analysis of sporadic case-control association and a transmission disequilibrium test in familial samples from South Indian population identified three associations: rs1062613 (p=3.12×10(-3)), a functional promoter variant of HTR3A; rs6710782 (p=3.50×10(-3)), an intronic variant of ERBB4; and rs891903 (p=1.05×10(-2)), an intronic variant of EBF1. The results support the risk variants observed in the earlier published work and suggest a potential role of neurodevelopmental genes in the schizophrenia pathogenesis. PMID:25579050

  9. Oral Bisphosphonates and Upper Gastrointestinal Cancer Risks in Asians with Osteoporosis: A Nested Case-Control Study Using National Retrospective Cohort Sample Data from Korea

    PubMed Central

    Park, Eun-Ja; Suh, Hae Sun; Park, Ji-Won; Kwon, Jin-Won

    2016-01-01

    Background Bisphosphonate can irritate the gastrointestinal mucosa and increase the risk of esophageal or gastric cancer. The relatively high prevalence of upper gastrointestinal cancers and the widespread use of bisphosphonate in Korea call for further investigation. We conducted a case-control study to evaluate the risk of esophageal or gastric cancer after exposure to oral bisphosphonates in Korean patients with osteoporosis. Methods We used the National Health Insurance Service-National Sample Cohort database of Korea from 2002 to 2013. Among osteoporotic patients (>40 years), cases were defined as incident diagnosis of esophageal or gastric cancer between 2006 and 2013. For each case, four controls were matched for age, sex, and income level by type of insurance. We categorized bisphosphonate use as non-user, recent user, past user, and past and recent user, depending on prescription in two periods (1 to 2 years and 2 to 4 years prior to the index date). We also assessed the duration of bisphosphonate use by measuring cumulative duration of exposure (CDE). To examine the association between oral bisphosphonates and esophageal or gastric cancer, we estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) using conditional logistic regression analysis, adjusting for concomitant diseases. Results A total of 1,708 cases and 6,832 controls were identified. The aORs (95% CIs) of recent, past, and continuous bisphosphonate use compared to non-users were 1.18 (0.93–1.51), 1.04 (0.83–1.29), and 1.25 (0.95–1.58)), respectively. In addition, no significant association was observed by CDE, even when different outcome definitions were applied. Conclusions This study did not prove an increased risk of esophageal or gastric cancer risk associated with bisphosphonate use, with respect to both risk windows and duration of exposure, in an Asian population-based, real-world setting. PMID:26937968

  10. The Effects of Dinner-to-Bed Time and Post-Dinner Walk on Gastric Cancer Across Different Age Groups: A Multicenter Case-Control Study in Southeast China.

    PubMed

    Xu, Le; Zhang, Xi; Lu, Jun; Dai, Jia-Xi; Lin, Ren-Qin; Tian, Fang-Xi; Liang, Bing; Guo, Yi-Nan; Luo, Hui-Yu; Li, Ni; Fang, Dong-Ping; Zhao, Ruo-Hua; Huang, Chang-Ming

    2016-04-01

    Gastric cancer (GC) remains a major killer throughout the world. Despite the dramatic decrease in GC over the last century, its etiology has not yet been well characterized.This study investigated the possible independent and combined effects of the dinner-to-bed time and post-dinner walk on the risk for GC across different age groups.A population-based, case-control study was conducted in southeast China, including 452 patients with GC and 465 age-, race-, and gender-matched controls. A self-designed questionnaire was used to collect information on demographic characteristics, dinner-to-bed time, post-dinner walk, and other behavioral factors. Conditional logistic regression models were used to estimate the effects of the dinner-to-bed time and post-dinner walk as well as their joint effect on the risk for GC across different age groups.Individuals with dinner-to-bed time <3 hours were more prone to have GC (P < 0.001), and the shorter the dinner-to-bed time was, the higher was the risk for GC (Ptrend < 0.001). Post-dinner nonwalk was associated with a 2.9-fold increased risk for GC compared with post-dinner walk (adjusted odds ratio [AOR] = 2.942, 95% confidence intervals [95% CIs] = 2.072-4.179). The interaction effect of dinner-to-bed time and post-dinner walk on GC risk was detected (AOR = 1.862, 95% CIs = 1.584-3.885, synergy index [SI] = 2.654, 95% CIs = 2.27-3.912). Participants with dinner-to-bed time <3 hours who did not walk after dinner were 7.4 times likely to suffer from GC (AOR = 7.401, 95% CIs = 4.523-13.16) than those with dinner-to-bed time ≥4 hours who took such walk. The risk of GC due to dinner-to-bed time <3 hours, post-dinner nonwalk and their interaction was positively correlated with age. The strongest risk was observed among people ≥70 years old, but the effects were not significant for people ≤55 years old.Dinner-to-bed time <3 hours and post-dinner nonwalk are independent risk

  11. Recalled Initiation and Duration of Maternal Breastfeeding Among Children with and Without ADHD in a Well Characterized Case-Control Sample.

    PubMed

    Stadler, Diane D; Musser, Erica D; Holton, Kathleen F; Shannon, Jackilen; Nigg, Joel T

    2016-02-01

    Early environmental influences are increasingly of interest in understanding ADHD as a neurodevelopmental condition, particularly in light of recognition that gene by environment interplay are likely involved in this condition. Breastfeeding duration predicts cognitive development, as well as development of brain white matter connectivity, in areas similar to those seen in ADHD. Prior studies show an association between breastfeeding and ADHD but without adequate evaluation of ADHD. A case control cohort of 474 children aged 7-13 years was examined, 291 with well characterized ADHD (71.5 % male) and the rest typically developing controls (51.9 % male). Mothers retrospectively reported on breast feeding initiation and duration. Initiation of breastfeeding was not associated with child ADHD, but shorter duration of breastfeeding was associated with child ADHD with a medium effect size (d = 0.40, p < 0.05); this effect held after covarying a broad set of potential confounders, including child oppositional defiant and conduct problems and including maternal and paternal ADHD symptoms. Effects were replicated across both parent and teacher ratings of child ADHD symptoms. Shorter duration of breastfeeding is among several risk factors in early life associated with future ADHD, or else longer duration is protective. The direction of this effect is unknown, however. It may be that some children are more difficult to breastfeed or that breastfeeding provides nutrients or other benefits that reduce future chance of ADHD. PMID:25749651

  12. Tradeoff between no-call reduction in genotyping error rate and loss of sample size for genetic case/control association studies.

    PubMed

    Kang, S J; Gordon, D; Brown, A M; Ott, J; Finch, S J

    2004-01-01

    Single nucleotide polymorphisms (SNP) may be genotyped for use in case-control designs to test for association between a SNP marker and a disease using a 2 x 3 chi-squared test of independence. Genotyping is often based on underlying continuous measurements, which are classified into genotypes. A "no-call" procedure is sometimes used in which borderline observations are not classified. This procedure has the simultaneous effect of reducing the genotype error rate and the expected number of genotypes observed. Both quantities affect the power of the statistic. We develop methods for calculating the genotype error rate, the expected number of genotypes observed, and the expected power of the resulting test as a function of the no-call procedure. We examine the statistical properties of the chi-squared test using a no-call procedure when the underlying continuous measure of genotype classification is a three-component mixture of univariate normal distributions under a range of parameter specifications. The genotype error rate decreases as the no-call region is increased. The expected number of observations genotyped also decreases. Our key finding is that the expected power of the chi-squared test is not sensitive to the no-call procedure. That is, the benefits of reduced genotype error rate are almost exactly balanced by the losses due to reduced genotype observations. For an underlying univariate normal mixture of genotype classification to be analyzed with a 2 x 3 chi-squared test, there is little, if any, increase in power using a no-call procedure. PMID:14992497

  13. Genetic variations in the CLNK gene and ZNF518B gene are associated with gout in case-control sample sets.

    PubMed

    Jin, Tian-Bo; Ren, Yongchao; Shi, Xugang; Jiri, Mutu; He, Na; Feng, Tian; Yuan, Dongya; Kang, Longli

    2015-07-01

    A genome-wide association study of gout in European populations identified 12 genetic variants strongly associated with risk of gout, but it is unknown whether these variants are also associated with gout risk in Chinese populations. A total of 145 patients with gout and 310 healthy control patients were recruited for a case-control association study. Twelve SNPs of CLNK and ZNF518B gene were genotyped, and association analysis was performed. Odds ratios (ORs) with 95 % confidence intervals (CIs) were used to assess the association. Overall, we found four risk alleles for gout in patients: the allele "G" of rs2041215 and rs1686947 in the CLNK gene by dominant model (OR 1.66; 95 % CI 1.04-2.63; p = 0.031) (OR 2.19; 95 % CI 1.38-3.46; p = 0.001) and additive model (OR 1.39; 95 % CI 1.00-1.93; p = 0.049) (OR 1.67; 95 % CI 1.19-2.32; p = 0.003), respectively, and the allele "A" of rs10938799 and rs10016022 in ZNF518B gene by recessive model (OR 4.66; 95 % CI 1.44-15.09; p = 0.008) (OR 4.54; 95 % CI 1.23-16.76; p = 0.020). Further haplotype analysis showed that the TCATTCTGA haplotype of CLNK was more frequent among patients with gout (adjusted OR 0.48; 95 % CI 0.24-0.95; p = 0.036). Additionally, polymorphisms of rs2041215, rs10938799, and rs17467273 were also correlated with clinical pathological parameters. This study provides evidence for gout susceptibility genes, CLNK and ZNF518B, in a Chinese population, which may have potential as diagnostic and prognostic marker for gout patients. PMID:25591661

  14. Optimal unified approach for rare-variant association testing with application to small-sample case-control whole-exome sequencing studies.

    PubMed

    Lee, Seunggeun; Emond, Mary J; Bamshad, Michael J; Barnes, Kathleen C; Rieder, Mark J; Nickerson, Deborah A; Christiani, David C; Wurfel, Mark M; Lin, Xihong

    2012-08-10

    We propose in this paper a unified approach for testing the association between rare variants and phenotypes in sequencing association studies. This approach maximizes power by adaptively using the data to optimally combine the burden test and the nonburden sequence kernel association test (SKAT). Burden tests are more powerful when most variants in a region are causal and the effects are in the same direction, whereas SKAT is more powerful when a large fraction of the variants in a region are noncausal or the effects of causal variants are in different directions. The proposed unified test maintains the power in both scenarios. We show that the unified test corresponds to the optimal test in an extended family of SKAT tests, which we refer to as SKAT-O. The second goal of this paper is to develop a small-sample adjustment procedure for the proposed methods for the correction of conservative type I error rates of SKAT family tests when the trait of interest is dichotomous and the sample size is small. Both small-sample-adjusted SKAT and the optimal unified test (SKAT-O) are computationally efficient and can easily be applied to genome-wide sequencing association studies. We evaluate the finite sample performance of the proposed methods using extensive simulation studies and illustrate their application using the acute-lung-injury exome-sequencing data of the National Heart, Lung, and Blood Institute Exome Sequencing Project. PMID:22863193

  15. Optimal Unified Approach for Rare-Variant Association Testing with Application to Small-Sample Case-Control Whole-Exome Sequencing Studies

    PubMed Central

    Lee, Seunggeun; Emond, Mary J.; Bamshad, Michael J.; Barnes, Kathleen C.; Rieder, Mark J.; Nickerson, Deborah A.; Christiani, David C.; Wurfel, Mark M.; Lin, Xihong

    2012-01-01

    We propose in this paper a unified approach for testing the association between rare variants and phenotypes in sequencing association studies. This approach maximizes power by adaptively using the data to optimally combine the burden test and the nonburden sequence kernel association test (SKAT). Burden tests are more powerful when most variants in a region are causal and the effects are in the same direction, whereas SKAT is more powerful when a large fraction of the variants in a region are noncausal or the effects of causal variants are in different directions. The proposed unified test maintains the power in both scenarios. We show that the unified test corresponds to the optimal test in an extended family of SKAT tests, which we refer to as SKAT-O. The second goal of this paper is to develop a small-sample adjustment procedure for the proposed methods for the correction of conservative type I error rates of SKAT family tests when the trait of interest is dichotomous and the sample size is small. Both small-sample-adjusted SKAT and the optimal unified test (SKAT-O) are computationally efficient and can easily be applied to genome-wide sequencing association studies. We evaluate the finite sample performance of the proposed methods using extensive simulation studies and illustrate their application using the acute-lung-injury exome-sequencing data of the National Heart, Lung, and Blood Institute Exome Sequencing Project. PMID:22863193

  16. Designing case-control studies.

    PubMed Central

    Yanagawa, T

    1979-01-01

    Identification of confounding factors, evaluation of their influence on cause-effect associations, and the introduction of appropriate ways to account for these factors are important considerations in designing case-control studies. This paper presents designs useful for these purposes, after first providing a statistical definition of a confounding factor. Differences in the ability to identify and evaluate confounding factors and estimate disease risk between designs employing stratification (matching) and designs randomly sampling cases and controls are noted. Linear logistic models for the analysis of data from such designs are described and are shown to liberalize design requirements and to increase relative risk estimation efficiency. The methods are applied to data from a multiple factor investigation of lung cancer patients and controls. PMID:540588

  17. Large-Scale Prospective T Cell Function Assays in Shipped, Unfrozen Blood Samples: Experiences from the Multicenter TRIGR Trial

    PubMed Central

    Cheung, Roy K.; Becker, Dorothy J.; Girgis, Rose; Palmer, Jerry P.; Cuthbertson, David; Krischer, Jeffrey P.

    2014-01-01

    Broad consensus assigns T lymphocytes fundamental roles in inflammatory, infectious, and autoimmune diseases. However, clinical investigations have lacked fully characterized and validated procedures, equivalent to those of widely practiced biochemical tests with established clinical roles, for measuring core T cell functions. The Trial to Reduce Insulin-dependent diabetes mellitus in the Genetically at Risk (TRIGR) type 1 diabetes prevention trial used consecutive measurements of T cell proliferative responses in prospectively collected fresh heparinized blood samples shipped by courier within North America. In this article, we report on the quality control implications of this simple and pragmatic shipping practice and the interpretation of positive- and negative-control analytes in our assay. We used polyclonal and postvaccination responses in 4,919 samples to analyze the development of T cell immunocompetence. We have found that the vast majority of the samples were viable up to 3 days from the blood draw, yet meaningful responses were found in a proportion of those with longer travel times. Furthermore, the shipping time of uncooled samples significantly decreased both the viabilities of the samples and the unstimulated cell counts in the viable samples. Also, subject age was significantly associated with the number of unstimulated cells and T cell proliferation to positive activators. Finally, we observed a pattern of statistically significant increases in T cell responses to tetanus toxin around the timing of infant vaccinations. This assay platform and shipping protocol satisfy the criteria for robust and reproducible long-term measurements of human T cell function, comparable to those of established blood biochemical tests. We present a stable technology for prospective disease-relevant T cell analysis in immunological diseases, vaccination medicine, and measurement of herd immunity. PMID:24334687

  18. Calibration and seasonal adjustment for matched case-control studies of vitamin D and cancer.

    PubMed

    Gail, Mitchell H; Wu, Jincao; Wang, Molin; Yaun, Shiaw-Shyuan; Cook, Nancy R; Eliassen, A Heather; McCullough, Marjorie L; Yu, Kai; Zeleniuch-Jacquotte, Anne; Smith-Warner, Stephanie A; Ziegler, Regina G; Carroll, Raymond J

    2016-06-15

    Vitamin D measurements are influenced by seasonal variation and specific assay used. Motivated by multicenter studies of associations of vitamin D with cancer, we formulated an analytic framework for matched case-control data that accounts for seasonal variation and calibrates to a reference assay. Calibration data were obtained from controls sampled within decile strata of the uncalibrated vitamin D values. Seasonal sine-cosine series were fit to control data. Practical findings included the following: (1) failure to adjust for season and calibrate increased variance, bias, and mean square error and (2) analysis of continuous vitamin D requires a variance adjustment for variation in the calibration estimate. An advantage of the continuous linear risk model is that results are independent of the reference date for seasonal adjustment. (3) For categorical risk models, procedures based on categorizing the seasonally adjusted and calibrated vitamin D have near nominal operating characteristics; estimates of log odds ratios are not robust to choice of seasonal reference date, however. Thus, public health recommendations based on categories of vitamin D should also define the time of year to which they refer. This work supports the use of simple methods for calibration and seasonal adjustment and is informing analytic approaches for the multicenter Vitamin D Pooling Project for Breast and Colorectal Cancer. Published 2016. This article has been contributed to by US Government employees and their work is in the public domain in the USA. PMID:27133461

  19. 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

  20. Multicenter evaluation of the thermo scientific prelude for measurement of immunosuppressant drugs using sample preparation liquid chromatography-tandem mass spectrometry.

    PubMed

    Peake, Roy W A; Hartigan, Christina R; Esposito, Christopher L; Kellogg, Mark D; Gabler, Jessica; Wang, Sihe; Breaud, Autumn; Di Bussolo, Joseph; Moskowitz, Joshua; Clarke, William

    2015-04-01

    Immunosuppressant drugs (ISDs) are commonly prescribed to solid organ transplant patients. Their narrow therapeutic index and potential for toxicity necessitates careful monitoring of blood concentrations. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods are increasingly used for ISD measurement. However, there remain many challenges with this methodology, particularly regarding interassay variability. The Thermo Scientific Prelude is an online extraction/liquid chromatography platform that uses turbulent flow technology coupled with MS/MS. A multicenter evaluation of the Prelude for the measurement of cyclosporine A, tacrolimus, and sirolimus is described. ISDs were measured at each site using standardized protocols. Sample preparation liquid chromatography-MS/MS was performed using the Prelude coupled to a TSQ Vantage. Chromatography was achieved with a Cyclone-P TurboFlow/Accucore C8 column combination using a multisolvent loading and eluting pump system. Mass spectrometry acquisitions were performed in selective reaction monitoring mode and data processed using TraceFinder (version 3.1). Multisite mean imprecision for cyclosporine A ranged from 8.8% (54 mcg/L) to 9.8% (450 mcg/L); for tacrolimus, 4.7% (15.5 mcg/L) to 12.6% (2.5 mcg/L); for sirolimus, 7.4% (19.9 mcg/L) to 16.5% (2.6 mcg/L). Approximately 110 specimens were used for method comparison. For cyclosporine A, mean bias against the multisite mean ranged from -18% to 1%; for tacrolimus, values ranged from -7% to 4%; for sirolimus, values ranged from -4% to 2%. Comparisons of multisite mean Prelude results with routine ISD method results was also performed for cyclosporine A (slope = 0.7878, intercept = 24.16, r = 0.98), tacrolimus (slope = 0.9391, intercept = 0.1017, r = 98), and sirolimus (slope = 0.9618, intercept = 0.1483, r = 0.97). The Prelude ISD method offers acceptable and comparable multisite performance. This study has also highlighted the importance of adopting standardized

  1. Measurement of 8-oxo-7,8-dihydro-2'-deoxyguanosine in peripheral blood mononuclear cells: optimisation and application to samples from a case-control study on cancers of the oesophagus and cardia.

    PubMed

    Breton, Jean; Sichel, François; Pottier, Didier; Prevost, Virginie

    2005-01-01

    8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) is a widely used biomarker to evaluate the level of oxidative stress. This study describes in its first part the optimisation of our analytical procedure (HPLC/electrochemical detection). Particular care was exercised to avoid artefactual oxidation and in the precision of measurement, which was evaluated with blood bags from hemochromatosis patients. The best results were obtained with a DNA extraction step using the "chaotropic method" recommended by the European Standards Committee on Oxidative DNA Damage (ESCODD). Other approaches such as anion exchange columns gave ten times as much 8-oxodG as this method. Moreover, a complete DNA hydrolysis using five different enzymes allowed improved precision. The optimised protocol was applied to peripheral blood mononuclear cells (PBMC) sampled during a case-control study on cancers of the oesophagus and cardia. With 7.2 +/- 2.6 8-oxodG/10(6) 2'-deoxyguanosines (2'-dG) (mean +/- SD), patients (n = 17) showed higher levels of 8-oxodG than controls (4.9 +/- 1.9 8-oxodG/10(6) 2'-dG, n = 43, Student's t-test: p < 0.001). This difference remained significant after technical (storage, sampling period, 2'-dG levels) and individual (age, sex, smoking, alcohol) confounding factors were taken into account (p < 0.0001, Generalised Linear regression Model). To our knowledge, this is the first report to demonstrate an increase of 8-oxodG in PBMCs of patients suffering from a cancer of the upper digestive tract. This elevated level of DNA damage in patients can raise interesting issues: is oxidative stress the cause or the result of the pathology? Could this biomarker be used to evaluate chemoprevention trials concerning digestive tract cancers? PMID:15875808

  2. A population-based nested case control study on recurrent pneumonias in children with severe generalized cerebral palsy: ethical considerations of the design and representativeness of the study sample

    PubMed Central

    Veugelers, Rebekka; Calis, Elsbeth AC; Penning, Corine; Verhagen, Arianne; Bernsen, Roos; Bouquet, Jan; Benninga, Marc A; Merkus, Peter JFM; Arets, Hubertus GM; Tibboel, Dick; Evenhuis, Heleen M

    2005-01-01

    Background In children with severe generalized cerebral palsy, pneumonias are a major health issue. Malnutrition, dysphagia, gastro-oesophageal reflux, impaired respiratory function and constipation are hypothesized risk factors. Still, no data are available on the relative contribution of these possible risk factors in the described population. This paper describes the initiation of a study in 194 children with severe generalized cerebral palsy, on the prevalence and on the impact of these hypothesized risk factors of recurrent pneumonias. Methods/Design A nested case-control design with 18 months follow-up was chosen. Dysphagia, respiratory function and constipation will be assessed at baseline, malnutrition and gastro-oesophageal reflux at the end of the follow-up. The study population consists of a representative population sample of children with severe generalized cerebral palsy. Inclusion was done through care-centres in a predefined geographical area and not through hospitals. All measurements will be done on-site which sets high demands on all measurements. If these demands were not met in "gold standard" methods, other methods were chosen. Although the inclusion period was prolonged, the desired sample size of 300 children was not met. With a consent rate of 33%, nearly 10% of all eligible children in the Netherlands are included (n = 194). The study population is subtly different from the non-participants with regard to severity of dysphagia and prevalence rates of pneumonias and gastro-oesophageal reflux. Discussion Ethical issues complicated the study design. Assessment of malnutrition and gastro-oesophageal reflux at baseline was considered unethical, since these conditions can be easily treated. Therefore, we postponed these diagnostics until the end of the follow-up. In order to include a representative sample, all eligible children in a predefined geographical area had to be contacted. To increase the consent rate, on-site measurements are of first

  3. Case-control study on analgesics and nephropathy (SAN): protocol

    PubMed Central

    Heinemann, Lothar AJ; Garbe, Edeltraut; Lewis, Michael; van der Woude, Fokko; Graf, Helmut

    2005-01-01

    Background The association between intake of non-phenacetin-containing analgesics and the occurrence of chronic renal failure is still controversially discussed. A new epidemiologic study was planned and conducted in Germany and Austria. Methods/design The objective of the international, multicenter case-control study was to evaluate the association between end-stage renal disease (ESRD) and use of non-phenacetin-containing analgesics with particular emphasis on combined formulations. A targeted sample of 1000 new (incident) dialysis patients, aged less than 50 years, was planned to recruit between January 1, 2001 and December 31, 2004. The age limit was chosen to avoid contamination of the study population with phenacetin-containing analgesics to the extent possible. Four control subjects per ESRD case, matched by age, sex, and region were selected from the population living in the region the case came from. Lifetime exposure to analgesics and potential renal risk factors were recorded in a single face-to-face interview. A set of aids was introduced to reinforce the memory of study participants. A standardized, pre-tested interview questionnaire (participants), a medical documentation sheet (physicians in dialysis centres), a logbook for all activities (dialysis centres) were used to collect the necessary data. Quality management consisted of the standardized procedures, (re-) training and supervision of interviewers, regular checks of all incoming data for completeness and plausibility. The study is scientifically independent and governed by a international Scientific Advisory Committee that bridged the gap between the sponsoring companies and the investigators. Also other advisory groups assisted the managing committee of the study. All relevant German and Austrian nephrological associations supported the study, and the study design was carefully reviewed and approved by the Kidney Foundation of Germany. Discussion The study is expected to answer the main

  4. 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…

  5. Recombinant human activated protein C resets thrombin generation in patients with severe sepsis – a case control study

    PubMed Central

    de Pont, Anne-Cornélie JM; Bakhtiari, Kamran; Hutten, Barbara A; de Jonge, Evert; Vroom, Margreeth B; Meijers, Joost CM; Büller, Harry R; Levi, Marcel

    2005-01-01

    Introduction Recombinant human activated protein C (rhAPC) is the first drug for which a reduction of mortality in severe sepsis has been demonstrated. However, the mechanism by which this reduction in mortality is achieved is still not clearly defined. The aim of the present study was to evaluate the dynamics of the anticoagulant, anti-inflammatory and pro-fibrinolytic action of rhAPC in patients with severe sepsis, by comparing rhAPC-treated patients with case controls. Methods In this prospectively designed multicenter case control study, 12 patients who were participating in the ENHANCE study, an open-label study of rhAPC in severe sepsis, were treated intravenously with rhAPC at a constant rate of 24 μg/kg/h for a total of 96 h. Twelve controls with severe sepsis matching the inclusion criteria received standard therapy. The treatment was started within 48 h after the onset of organ failure. Blood samples were taken before the start of the infusion and at 4, 8, 24, 48, 96 and 168 h, for determination of parameters of coagulation and inflammation. Results Sepsis-induced thrombin generation as measured by thrombin-antithrombin complexes and prothrombin fragment F1+2, was reset by rhAPC within the first 8 h of infusion. The administration of rhAPC did not influence parameters of fibrinolysis and inflammation. There was no difference in outcome or occurrence of serious adverse events between the treatment group and the control group. Conclusion Sepsis-induced thrombin generation in severely septic patients is reset by rhAPC within the first 8 h of infusion without influencing parameters of fibrinolysis and inflammation. PMID:16277710

  6. Multicenter case-control study of the risk factors for ulcerative colitis in China

    PubMed Central

    Wang, Yu-Fang; Ou-yang, Qin; Xia, Bing; Liu, Li-Na; Gu, Fang; Zhou, Kai-Fang; Mei, Qiao; Shi, Rui-Hua; Ran, Zhi-Hua; Wang, Xiao-Di; Hu, Pin-Jin; Wu, Kai-Chun; Liu, Xin-Guang; Miao, Ying-Lei; Han, Ying; Wu, Xiao-Ping; He, Guo-Bing; Zhong, Jie; Liu, Guan-Jian

    2013-01-01

    AIM: To evaluate potential risk factors in the development of ulcerative colitis (UC) in China. METHODS: A total of 1308 patients with UC and 1308 age-matched and sex-matched controls were prospectively studied in China. The UC cases were collected from 17 hospitals in China from April 2007 to April 2010. Uniform questionnaires were designed to investigate risk factors including smoking, appendectomy, stress, socio-economic conditions, nonsteroidal anti-inflammatory drugs (NSAIDs), oral contraceptives, diet, breastfeeding, infections and family sanitary conditions. Group comparisons by each factor were done using simple logistic regression analysis. Conditional logistic regression was used for multivariate analysis. RESULTS: By univariate analysis, the variables predictive of UC included feeling stress, light and heavy alcoholic drinking, spicy food, sugar consumption and infectious diarrhea, while heavy tea intake and tap water consumption were protective against UC. On multivariate analysis, the protective factor for UC was tap water consumption [odds ratios (OR) = 0.424, 95%CI: 0.302-0.594, P < 0.001]; while the potential risk factors for UC were heavy sugar consumption (OR = 1.632, 95%CI: 1.156-2.305, P < 0.001), spicy food (light intake: OR = 3.329, 95%CI: 2.282-4.857, P < 0.001; heavy intake: OR = 3.979, 95%CI: 2.700-5.863, P < 0.001), and often feeling stress (OR = 1.981, 95%CI: 1.447-2.711, P < 0.001). Other factors, such as smoking habit, appendectomy, breastfeeding, a history of measles, rural or urban residence, education, oral contraceptives, and NSAID use have not been found to have a significant association with the development of UC in the present study. CONCLUSION: Our study showed tap water consumption was a protective factor for UC, while spicy food, heavy sugar consumption and often feeling stress were risk factors for UC in this Chinese population. PMID:23555172

  7. Association between aflatoxin B1 occupational airway exposure and risk of hepatocellular carcinoma: a case-control study.

    PubMed

    Lai, Hao; Mo, Xianwei; Yang, Yang; He, Ke; Xiao, Jun; Liu, Chao; Chen, Jiansi; Lin, Yuan

    2014-10-01

    The aim of this study was to determine the airway exposure of sugar and papermaking factory workers to aflatoxin B1 (AFB1) and to explore the potential association between AFB1 airway exposure and the risk of hepatocellular carcinoma (HCC) in a case-control study. Dust samples were collected from the sugarcane bagasse warehouse, and presser and paper production workshops. Blood samples were collected from 181 workshop employees and 203 controls who worked outside the workshop. AFB1 albumin adducts were detected using a double antibody sandwich enzyme-linked immunosorbent assay (ELISA). To explore the association between AFB1 airway exposure and the risk of HCC, the medical records of 68 HCC patients who worked in a sugar and papermaking factory between January 1994 and December 2013 were analyzed. A questionnaire was used to collect information from 150 healthy controls who worked for the same company and lived near the factory. AFB1 was detected in the dust samples, but could not be detected in any of the rice samples. An analysis of serum samples revealed serum AFB1 albumin adducts in 102 (56.35 %) of the study participants. However, in the control group, only 12 (5.9 %) individuals had detectable levels of AFB1 albumin adducts. Those with airway exposure to Aspergillus flavus-contaminated dust had an elevated risk of HCC compared to those without exposure (odds ratio, 5.24; 95 % confidence interval, 2.77-9.88; P = 0.00). The findings of this study indicate that occupational AFB1 airway exposure might be associated with the risk of AFB1-related HCC among the population that was used in this study. Intervention programs aimed at reducing exposure to inhalational AFB1 are needed urgently. Additional suitably designed, multicenter, prospective studies using large samples are needed to further confirm the results. PMID:24961349

  8. Population-based, Case-Control-Family Design to Investigate Genetic and Environmental Influences on Melanoma Risk

    PubMed Central

    Cust, Anne E.; Schmid, Helen; Maskiell, Judith A.; Jetann, Jodie; Ferguson, Megan; Holland, Elizabeth A.; Agha-Hamilton, Chantelle; Jenkins, Mark A.; Kelly, John; Kefford, Richard F.; Giles, Graham G.; Armstrong, Bruce K.; Aitken, Joanne F.; Hopper, John L.; Mann, Graham J.

    2009-01-01

    Discovering and understanding genetic risk factors for melanoma and their interactions with phenotype, sun exposure, and other risk factors could lead to new strategies for melanoma control. This paper describes the Australian Melanoma Family Study, which uses a multicenter, population-based, case-control-family design. From 2001 to 2005, the authors recruited 1,164 probands including 629 cases with histopathologically confirmed, first-primary cutaneous melanoma diagnosed before age 40 years, 240 population-based controls frequency matched for age, and 295 spouse/friend controls. Information on lifetime sun exposure, phenotype, and residence history was collected for probands and nearly 4,000 living relatives. More than 3,000 subjects donated a blood sample. Proxy-reported information was collected for childhood sun exposure and deceased relatives. Important features of this study include the population-based, family-based design; a focus on early onset disease; probands from 3 major cities differing substantially in solar ultraviolet exposure and melanoma incidence; a population at high risk because of high ultraviolet exposure and susceptible pigmentation phenotypes; population-based, spouse/friend, and sibling controls; systematic recruitment of relatives of case and control probands; self and parent reports of childhood sun exposure; and objective clinical skin examinations. The authors discuss methodological and analytical issues related to the study design and conduct, as well as the potentially novel insights the study can deliver. PMID:19887461

  9. Evaluation of a Minimally Invasive Cell Sampling Device Coupled with Assessment of Trefoil Factor 3 Expression for Diagnosing Barrett's Esophagus: A Multi-Center Case–Control Study

    PubMed Central

    Ross-Innes, Caryn S.; Debiram-Beecham, Irene; O'Donovan, Maria; Walker, Elaine; Varghese, Sibu; Lao-Sirieix, Pierre; Lovat, Laurence; Griffin, Michael; Ragunath, Krish; Haidry, Rehan; Sami, Sarmed S.; Kaye, Philip; Novelli, Marco; Disep, Babett; Ostler, Richard; Aigret, Benoit; North, Bernard V.; Bhandari, Pradeep; Haycock, Adam; Morris, Danielle; Attwood, Stephen; Dhar, Anjan; Rees, Colin; Rutter, Matthew D. D.; Sasieni, Peter D.; Fitzgerald, Rebecca C.

    2015-01-01

    Background Barrett's esophagus (BE) is a commonly undiagnosed condition that predisposes to esophageal adenocarcinoma. Routine endoscopic screening for BE is not recommended because of the burden this would impose on the health care system. The objective of this study was to determine whether a novel approach using a minimally invasive cell sampling device, the Cytosponge, coupled with immunohistochemical staining for the biomarker Trefoil Factor 3 (TFF3), could be used to identify patients who warrant endoscopy to diagnose BE. Methods and Findings A case–control study was performed across 11 UK hospitals between July 2011 and December 2013. In total, 1,110 individuals comprising 463 controls with dyspepsia and reflux symptoms and 647 BE cases swallowed a Cytosponge prior to endoscopy. The primary outcome measures were to evaluate the safety, acceptability, and accuracy of the Cytosponge-TFF3 test compared with endoscopy and biopsy. In all, 1,042 (93.9%) patients successfully swallowed the Cytosponge, and no serious adverse events were attributed to the device. The Cytosponge was rated favorably, using a visual analogue scale, compared with endoscopy (p < 0.001), and patients who were not sedated for endoscopy were more likely to rate the Cytosponge higher than endoscopy (Mann-Whitney test, p < 0.001). The overall sensitivity of the test was 79.9% (95% CI 76.4%–83.0%), increasing to 87.2% (95% CI 83.0%–90.6%) for patients with ≥3 cm of circumferential BE, known to confer a higher cancer risk. The sensitivity increased to 89.7% (95% CI 82.3%–94.8%) in 107 patients who swallowed the device twice during the study course. There was no loss of sensitivity in patients with dysplasia. The specificity for diagnosing BE was 92.4% (95% CI 89.5%–94.7%). The case–control design of the study means that the results are not generalizable to a primary care population. Another limitation is that the acceptability data were limited to a single measure. Conclusions The

  10. On combining family and case-control studies.

    PubMed

    Pfeiffer, Ruth M; Pee, David; Landi, Maria T

    2008-11-01

    Studies to detect genetic association with disease can be family-based, often using families with multiple affected members, or population based, as in population-based case-control studies. If data on both study types are available from the same population, it is useful to combine them to improve power to detect genetic associations. Two aspects of the data need to be accommodated, the sampling scheme and potential residual correlations among family members. We propose two approaches for combining data from a case-control study and a family study that collected families with multiple cases. In the first approach, we view a family as the sampling unit and specify the joint likelihood for the family members using a two-level mixed effects model to account for random familial effects and for residual genetic correlations among family members. The ascertainment of the families is accommodated by conditioning on the ascertainment event. The individuals in the case-control study are treated as families of size one, and their unconditional likelihood is combined with the conditional likelihood for the families. This approach yields subject specific maximum likelihood estimates of covariate effects. In the second approach, we view an individual as the sampling unit. The sampling scheme is accommodated using two-phase sampling techniques, marginal covariate effects are estimated, and correlations among family members are accounted for in the variance calculations. The models are compared in simulations. Data from a case-control and a family study from north-eastern Italy on melanoma and a low-risk melanoma-susceptibility gene, MC1R, are used to illustrate the approaches. PMID:18454494

  11. Multicenter Breast Cancer Collaborative Registry

    PubMed Central

    Sherman, Simon; Shats, Oleg; Fleissner, Elizabeth; Bascom, George; Yiee, Kevin; Copur, Mehmet; Crow, Kate; Rooney, James; Mateen, Zubeena; Ketcham, Marsha A.; Feng, Jianmin; Sherman, Alexander; Gleason, Michael; Kinarsky, Leo; Silva-Lopez, Edibaldo; Edney, James; Reed, Elizabeth; Berger, Ann; Cowan, Kenneth

    2011-01-01

    The Breast Cancer Collaborative Registry (BCCR) is a multicenter web-based system that efficiently collects and manages a variety of data on breast cancer (BC) patients and BC survivors. This registry is designed as a multi-tier web application that utilizes Java Servlet/JSP technology and has an Oracle 11g database as a back-end. The BCCR questionnaire has accommodated standards accepted in breast cancer research and healthcare. By harmonizing the controlled vocabulary with the NCI Thesaurus (NCIt) or Systematized Nomenclature of Medicine-Clinical Terms (SNOMED-CT), the BCCR provides a standardized approach to data collection and reporting. The BCCR has been recently certified by the National Cancer Institute’s Center for Biomedical Informatics and Information Technology (NCI CBIIT) as a cancer Biomedical Informatics Grid (caBIG®) Bronze Compatible product. The BCCR is aimed at facilitating rapid and uniform collection of critical information and biological samples to be used in developing diagnostic, prevention, treatment, and survivorship strategies against breast cancer. Currently, seven cancer institutions are participating in the BCCR that contains data on almost 900 subjects (BC patients and survivors, as well as individuals at high risk of getting BC). PMID:21918596

  12. Multicenter breast cancer collaborative registry.

    PubMed

    Sherman, Simon; Shats, Oleg; Fleissner, Elizabeth; Bascom, George; Yiee, Kevin; Copur, Mehmet; Crow, Kate; Rooney, James; Mateen, Zubeena; Ketcham, Marsha A; Feng, Jianmin; Sherman, Alexander; Gleason, Michael; Kinarsky, Leo; Silva-Lopez, Edibaldo; Edney, James; Reed, Elizabeth; Berger, Ann; Cowan, Kenneth

    2011-01-01

    The Breast Cancer Collaborative Registry (BCCR) is a multicenter web-based system that efficiently collects and manages a variety of data on breast cancer (BC) patients and BC survivors. This registry is designed as a multi-tier web application that utilizes Java Servlet/JSP technology and has an Oracle 11g database as a back-end. The BCCR questionnaire has accommodated standards accepted in breast cancer research and healthcare. By harmonizing the controlled vocabulary with the NCI Thesaurus (NCIt) or Systematized Nomenclature of Medicine-Clinical Terms (SNOMED-CT), the BCCR provides a standardized approach to data collection and reporting. The BCCR has been recently certified by the National Cancer Institute's Center for Biomedical Informatics and Information Technology (NCI CBIIT) as a cancer Biomedical Informatics Grid (caBIG(®)) Bronze Compatible product.The BCCR is aimed at facilitating rapid and uniform collection of critical information and biological samples to be used in developing diagnostic, prevention, treatment, and survivorship strategies against breast cancer. Currently, seven cancer institutions are participating in the BCCR that contains data on almost 900 subjects (BC patients and survivors, as well as individuals at high risk of getting BC). PMID:21918596

  13. Association between Dopamine Receptor D2 (DRD2) Variations rs6277 and rs1800497 and Cognitive Performance According to Risk Type for Psychosis: A Nested Case Control Study in a Finnish Population Sample

    PubMed Central

    Ramsay, Hugh; Barnett, Jennifer H.; Miettunen, Jouko; Mukkala, Sari; Mäki, Pirjo; Liuhanen, Johanna; Murray, Graham K.; Jarvelin, Marjo-Riitta; Ollila, Hanna; Paunio, Tiina; Veijola, Juha

    2015-01-01

    Background There is limited research regarding the association between genes and cognitive intermediate phenotypes in those at risk for psychotic disorders. Methods We measured the association between established psychosis risk variants in dopamine D2 receptor (DRD2) and cognitive performance in individuals at age 23 years and explored if associations between cognition and these variants differed according to the presence of familial or clinical risk for psychosis. The subjects of the Oulu Brain and Mind Study were drawn from the general population-based Northern Finland 1986 Birth Cohort (NFBC 1986). Using linear regression, we compared the associations between cognitive performance and two candidate DRD2 polymorphisms (rs6277 and rs1800497) between subjects having familial (n=61) and clinical (n=45) risk for psychosis and a random sample of participating NFBC 1986 controls (n=74). Cognitive performance was evaluated using a comprehensive battery of tests at follow-up. Results Principal components factor analysis supported a three-factor model for cognitive measures. The minor allele of rs6277 was associated with poorer performance on a verbal factor (p=0.003) but this did not significantly interact with familial or clinical risk for psychosis. The minor allele of rs1800497 was associated with poorer performance on a psychomotor factor (p=0.038), though only in those at familial risk for psychotic disorders (interaction p=0.049). Conclusion The effect of two DRD2 SNPs on cognitive performance may differ according to risk type for psychosis, suggesting that cognitive intermediate phenotypes differ according to the type (familial or clinical) risk for psychosis. PMID:26114663

  14. [Research progress on case-control study].

    PubMed

    Zhang, F F; Liu, Z D; Zhang, C X; Jiang, B F

    2016-04-10

    Several new varients related to the case-control designs have been developed in the recent decades, and this article briefly summarized four new designs: two-stage design, case-specular study, exposure-crossover study and case-case-time-control study. This paper involved principles of study design, requisites for application, advantages and disadvantages on all the studies. PMID:27087230

  15. 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

  16. 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

  17. Occupational risk factors for small bowel carcinoid tumor: a European population-based case-control study.

    PubMed

    Kaerlev, Linda; Teglbjaerg, Peter Stubbe; Sabroe, Svend; Kolstad, Henrik A; Ahrens, Wolfgang; Eriksson, Mikael; Guénel, Pascal; Hardell, Lennart; Cyr, Diane; Ballard, Terri; Zambon, Paola; Morales Suárez-Varela, María M; Stang, Andreas; Olsen, Jorn

    2002-06-01

    Small bowel carcinoid tumor (SBC) is a rare disease of unknown etiology but with an age-, sex-, and place-specific occurrence that may indicate an occupational origin. A European multicenter population-based case-control study was conducted from 1995 through 1997. Incident SBC cases between 35 and 69 years of age (n = 101) were identified, together with 3335 controls sampled from the catchment area of the cases. Histological review performed by a reference pathologist left 99 cases for study; 84 cases and 2070 population controls were interviewed. The industries most closely associated (a twofold or more odds ratio [OR]) with SBC, taking into account a 10-year time lag after exposure were, among women, employment in wholesale industry of food and beverages (OR, 8.2; 95% confidence interval [CI], 1.9 to 34.9]) and among men, manufacture of motor vehicle bodies (OR, 5.2; 95% CI, 1.2 to 22.4), footwear (OR, 3.9; 95% CI, 0.9 to 16.1), and metal structures (OR, 3.3; 95% CI, 1.0 to 10.4). The identified high-risk occupations with an OR above 2 were shoemakers, structural metal preparers, construction painters and other construction workers, bookkeepers, machine fitters, and welders (men). The OR for regular occupational use of organic solvents for at least half a year was 2.0 (95% CI, 1.0 to 4.2). Exposure to rust-preventive paint containing lead was suggested as another potential occupational exposure (OR, 9.1; 95% CI, 0.8 to 107). This explorative study suggests an association between certain occupational exposures and SBC, but some of these associations could be attributable to chance. All findings should be regarded as tentative. PMID:12085477

  18. Bayesian adjustment for exposure misclassification in case-control studies.

    PubMed

    Chu, Rong; Gustafson, Paul; Le, Nhu

    2010-04-30

    Poor measurement of explanatory variables occurs frequently in observational studies. Error-prone observations may lead to biased estimation and loss of power in detecting the impact of explanatory variables on the response. We consider misclassified binary exposure in the context of case-control studies, assuming the availability of validation data to inform the magnitude of the misclassification. A Bayesian adjustment to correct the misclassification is investigated. Simulation studies show that the Bayesian method can have advantages over non-Bayesian counterparts, particularly in the face of a rare exposure, small validation sample sizes, and uncertainty about whether exposure misclassification is differential or non-differential. The method is illustrated via application to several real studies. PMID:20087839

  19. 77 FR 11136 - Proposed Collection; Comment Request; a Multi-Center International Hospital-Based Case-Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

    ... identification of the key, functional alleles in gene regions associated with risk of NHL requires further..., prevalence of exposures, correlations between exposures, and variation in gene regions of particular...

  20. Relationship between Urinary N-Desmethyl-Acetamiprid and Typical Symptoms including Neurological Findings: A Prevalence Case-Control Study

    PubMed Central

    Ikenaka, Yoshinori; Nakayama, Shouta M. M.; Mizukawa, Hazuki; Aoyama, Yoshiko; Ishizuka, Mayumi; Taira, Kumiko

    2015-01-01

    Neonicotinoid insecticides are nicotinic acetylcholine receptor agonists used worldwide. Their environmental health effects including neurotoxicity are of concern. We previously determined a metabolite of acetamiprid, N-desmethyl-acetamiprid in the urine of a patient, who exhibited some typical symptoms including neurological findings. We sought to investigate the association between urinary N-desmethyl-acetamiprid and the symptoms by a prevalence case-control study. Spot urine samples were collected from 35 symptomatic patients of unknown origin and 50 non-symptomatic volunteers (non-symptomatic group, NSG, 4–87 year-old). Patients with recent memory loss, finger tremor, and more than five of six symptoms (headache, general fatigue, palpitation/chest pain, abdominal pain, muscle pain/weakness/spasm, and cough) were in the typical symptomatic group (TSG, n = 19, 5–69 year-old); the rest were in the atypical symptomatic group (ASG, n = 16, 5–78 year-old). N-desmethyl-acetamiprid and six neonicotinoids in the urine were quantified by liquid chromatography-tandem mass spectrometry. The detection of N-desmethyl-acetamiprid was the most frequent and highest in TSG (47.4%, 6.0 ppb (frequency, maximum)), followed by in ASG (12.5%, 4.4 ppb) and in NSG (6.0%, 2.2 ppb), however acetamiprid was not detected. Thiamethoxam was detected in TSG (31.6%, 1.4 ppb), in ASG (6.3%, 1.9 ppb), but not in NSG. Nitenpyram was detected in TSG (10.5%, 1.2 ppb), in ASG (6.3%, not quantified) and in NSG (2.0%, not quantified). Clothianidin was only detected in ASG (6.3%, not quantified), and in NSG (2.0%, 1.6 ppb). Thiacloprid was detected in ASG (6.3%, 0.1 ppb). The cases in TSG with detection of N-desmethyl-acetamiprid and thiamethoxam were aged 5 to 62 years and 13 to 62 years, respectively. Detection of N-desmethyl-acetamiprid was associated with increased prevalence of the symptoms (odds ratio: 14, 95% confidence interval: 3.5–57). Urinary N-desmethyl-acetamiprid can be used as a

  1. Relationship between Urinary N-Desmethyl-Acetamiprid and Typical Symptoms including Neurological Findings: A Prevalence Case-Control Study.

    PubMed

    Marfo, Jemima Tiwaa; Fujioka, Kazutoshi; Ikenaka, Yoshinori; Nakayama, Shouta M M; Mizukawa, Hazuki; Aoyama, Yoshiko; Ishizuka, Mayumi; Taira, Kumiko

    2015-01-01

    Neonicotinoid insecticides are nicotinic acetylcholine receptor agonists used worldwide. Their environmental health effects including neurotoxicity are of concern. We previously determined a metabolite of acetamiprid, N-desmethyl-acetamiprid in the urine of a patient, who exhibited some typical symptoms including neurological findings. We sought to investigate the association between urinary N-desmethyl-acetamiprid and the symptoms by a prevalence case-control study. Spot urine samples were collected from 35 symptomatic patients of unknown origin and 50 non-symptomatic volunteers (non-symptomatic group, NSG, 4-87 year-old). Patients with recent memory loss, finger tremor, and more than five of six symptoms (headache, general fatigue, palpitation/chest pain, abdominal pain, muscle pain/weakness/spasm, and cough) were in the typical symptomatic group (TSG, n = 19, 5-69 year-old); the rest were in the atypical symptomatic group (ASG, n = 16, 5-78 year-old). N-desmethyl-acetamiprid and six neonicotinoids in the urine were quantified by liquid chromatography-tandem mass spectrometry. The detection of N-desmethyl-acetamiprid was the most frequent and highest in TSG (47.4%, 6.0 ppb (frequency, maximum)), followed by in ASG (12.5%, 4.4 ppb) and in NSG (6.0%, 2.2 ppb), however acetamiprid was not detected. Thiamethoxam was detected in TSG (31.6%, 1.4 ppb), in ASG (6.3%, 1.9 ppb), but not in NSG. Nitenpyram was detected in TSG (10.5%, 1.2 ppb), in ASG (6.3%, not quantified) and in NSG (2.0%, not quantified). Clothianidin was only detected in ASG (6.3%, not quantified), and in NSG (2.0%, 1.6 ppb). Thiacloprid was detected in ASG (6.3%, 0.1 ppb). The cases in TSG with detection of N-desmethyl-acetamiprid and thiamethoxam were aged 5 to 62 years and 13 to 62 years, respectively. Detection of N-desmethyl-acetamiprid was associated with increased prevalence of the symptoms (odds ratio: 14, 95% confidence interval: 3.5-57). Urinary N-desmethyl-acetamiprid can be used as a

  2. Testing Goodness-of-Fit for the Proportional Hazards Model based on Nested Case-Control Data

    PubMed Central

    Lu, Wenbin; Liu, Mengling; Chen, Yi-Hau

    2014-01-01

    Summary Nested case-control sampling is a popular design for large epidemiological cohort studies due to its cost effectiveness. A number of methods have been developed for the estimation of the proportional hazards model with nested case-control data; however, the evaluation of modeling assumption is less attended. In this paper, we propose a class of goodness-of-fit test statistics for testing the proportional hazards assumption based on nested case-control data. The test statistics are constructed based on asymptotically mean-zero processes derived from Samuelsen’s maximum pseudo-likelihood estimation method. In addition, we develop an innovative resampling scheme to approximate the asymptotic distribution of the test statistics while accounting for the dependent sampling scheme of nested case-control design. Numerical studies are conducted to evaluate the performance of our proposed approach, and an application to the Wilms’ Tumor Study is given to illustrate the methodology. PMID:25298193

  3. Testing goodness-of-fit for the proportional hazards model based on nested case-control data.

    PubMed

    Lu, Wenbin; Liu, Mengling; Chen, Yi-Hau

    2014-12-01

    Nested case-control sampling is a popular design for large epidemiological cohort studies due to its cost effectiveness. A number of methods have been developed for the estimation of the proportional hazards model with nested case-control data; however, the evaluation of modeling assumption is less attended. In this article, we propose a class of goodness-of-fit test statistics for testing the proportional hazards assumption based on nested case-control data. The test statistics are constructed based on asymptotically mean-zero processes derived from Samuelsen's maximum pseudo-likelihood estimation method. In addition, we develop an innovative resampling scheme to approximate the asymptotic distribution of the test statistics while accounting for the dependent sampling scheme of nested case-control design. Numerical studies are conducted to evaluate the performance of our proposed approach, and an application to the Wilms' Tumor Study is given to illustrate the methodology. PMID:25298193

  4. The role of human papillomavirus in head and neck squamous cell carcinoma: A case control study on a southern Chinese population.

    PubMed

    Chor, Josette S Y; Vlantis, Alexander C; Chow, Tam-Lin; Fung, Siu-Chung; Ng, Fiona Y H; Lau, Chi-Hung; Chan, Amy B W; Ho, Luen-Cheung; Kwong, Wing-Hang; Fung, Mandy N S; Lam, Eddy W H; Mak, Kwong-Lin; Lam, Holly C Y; Kok, Amy S Y; Ho, Wendy C S; Yeung, Apple C M; Chan, Paul K S

    2016-05-01

    HPV plays a role in the development of a portion of head and neck squamous cell carcinoma (HNSCC), but only limited information on its role in southern Chinese population is available. A multicenter case-control study was conducted. HPV type, viral integration, E6/7 mRNA expression status, and TP53 mutation were determined. A total of 228 HNSCC were recruited including 137 (60.1%) oral SCC, 34 (14.9%) oropharyngeal SCC, 31 (13.6%) laryngeal SCC, 21 (9.2%) hypopharyngeal SCC, and 5 (2.2%) lip and paranasal sinus SCC. High-risk HPV infection was found in 7.5% (17/228) of HNSCC, but only a small proportion of samples had evidence of viral integration (5.3%, 12/228) or E6/7 mRNA expression (4.4%, 10/228). HPV infection with oncogenic phenotype (integration and E6/7 mRNA expression) was significantly more common in oropharyngeal SCC than controls (9/34, 26.5% vs. 0/42, 0.0%, P < 0.001). Smoking showed a significant association with HNSCC, oropharyngeal SCC, and laryngeal SCC. TP53 mutation was associated with HNSCC (P < 0.001). Older age, TP53 mutation, and HPV16 infection with oncogenic phenotypes were independently associated factors for HNSCC with odds ratios of 1.03 (1.02-1.05), 3.38 (1.71-6.66), and 9.19 (1.13-74.68), respectively. High-risk HPV infection of head and neck mucosa is not uncommon in the Hong Kong population. This study found that 26-30% of oropharyngeal carcinoma was associated with HPV infection, mostly HPV16, and that smoking which predisposes to TP53 mutations was another important risk factor. PMID:26467027

  5. Outdoor Air Pollution and Cardiovascular Diseases in Lebanon: A Case-Control Study

    PubMed Central

    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. PMID:25653681

  6. 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. PMID:25653681

  7. Multicenter Study of Hand Carriage of Potential Pathogens by Neonatal ICU Healthcare Personnel.

    PubMed

    Ferng, Yu-hui; Clock, Sarah A; Wong-Mcloughlin, Jennifer; DeLaMora, Patricia A; Perlman, Jeffrey M; Gray, Kelly S; Paul, David A; Prasad, Priya A; Zaoutis, Theoklis E; Alba, Luis R; Whittier, Susan; Larson, Elaine L; Saiman, Lisa

    2015-09-01

    A multicenter surveillance study was performed to determine the rates of hand carriage of potential pathogens among healthcare personnel in four neonatal intensive care units. Staphylococcus aureus, enterococci, and gram-negative bacilli were recovered from 8%, 3%, and 2% of 1000 hand culture samples, respectively. PMID:26336605

  8. Multicenter Study of Hand Carriage of Potential Pathogens by Neonatal ICU Healthcare Personnel

    PubMed Central

    Ferng, Yu-hui; Clock, Sarah A.; Wong-Mcloughlin, Jennifer; DeLaMora, Patricia A.; Perlman, Jeffrey M.; Gray, Kelly S.; Paul, David A.; Prasad, Priya A.; Zaoutis, Theoklis E.; Alba, Luis R.; Whittier, Susan; Larson, Elaine L.; Saiman, Lisa

    2015-01-01

    A multicenter surveillance study was performed to determine the rates of hand carriage of potential pathogens among healthcare personnel in four neonatal intensive care units. Staphylococcus aureus, enterococci, and gram-negative bacilli were recovered from 8%, 3%, and 2% of 1000 hand culture samples, respectively. PMID:26336605

  9. Sialolithiasis is associated with nephrolithiasis: a case-control study.

    PubMed

    Wu, Chuan-Chang; Hung, Shih-Han; Lin, Herng-Ching; Lee, Cha-Ze; Lee, Hsin-Chien; Chung, Shiu-Dong

    2016-05-01

    Conclusions This study demonstrates an association between sialolithiasis and nephrolithiasis. The results call for more awareness of this association among physicians and patients with nephrolithiasis. Objective Very few empirical studies have been conducted to explore the potential association between sialolithiasis and nephrolithiasis. As such, the association between sialolithiasis and nephrolithiasis still remains unclear. This study aimed to explore the possible association between sialolithiasis and nephrolithiasis using a population-based dataset. Methods Using data from the Taiwan Longitudinal Health Insurance Database 2005, this case-control study identified 966 patients with sialolithiasis as cases and 2898 sex- and age-matched subjects without sialolithiasis as controls. Conditional logistic regressions were conducted to examine the association of sialolithiasis with previously diagnosed nephrolithiasis. Results Out of 3864 sampled patients, 165 (4.27%) had prior nephrolithiasis. Using Chi-square test, it was found that there was a significant difference in the prevalence of prior nephrolithiasis between the cases and controls (10.25% vs 2.28%, p < 0.001). Moreover, by conditional logistic regression analysis, the odds ratio of prior nephrolithiasis for cases was 4.74 (95% CI = 3.41-6.58, p < 0.001) when compared to controls after adjusting for monthly income, geographic location, urbanization level of residence, diabetes, hypertension, heart failure, chronic renal disease, and tobacco use. PMID:26808906

  10. Analysis of Secondary Outcomes in Nested Case-Control Study Designs

    PubMed Central

    Kim, Ryung S.; Kaplan, Robert C.

    2014-01-01

    One of the main perceived advantages of using a case-cohort design compared to 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 originally proposed by Samuelsen (1997) 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 to that of the case-cohort design when the primary and secondary outcomes were positively correlated. The proposed method is illustrated with data from a cohort in Cardiovascular Health Study to study the association of C-reactive protein levels and the incidence of congestive heart failure. PMID:24919979

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

    PubMed Central

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

    2011-01-01

    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/cm2) 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. PMID:22135150

  12. Multicenter comparative study of a new ELISA, PLATELIA RABIES II, for the detection and titration of anti-rabies glycoprotein antibodies and comparison with the rapid fluorescent focus inhibition test (RFFIT) on human samples from vaccinated and non-vaccinated people.

    PubMed

    Feyssaguet, M; Dacheux, L; Audry, L; Compoint, A; Morize, J L; Blanchard, I; Bourhy, H

    2007-03-01

    The envelope glycoprotein G of rabies virus induces the production of neutralising antibodies, which are important in protection against rabies. Therefore, titration of anti-envelope glycoprotein antibodies is a good indicator of the degree of immunity in people during anti-rabies treatment or after vaccination. According to the World Health Organization (WHO) guidelines, a booster vaccine dose should be given if the rabies antibody titre falls below 0.5 IU/ml. Titration of anti-rabies antibodies is also useful for plasma centers in the preparation and standardization of human anti-rabies gamma-globulins for therapeutic use and to a lesser extent for the diagnosis of rabies in human sera and cerebrospinal fluid (CSF). This paper presents a new enzyme-linked immunosorbent assay (ELISA), PLATELIA RABIES II, developed for rabies envelope glycoprotein antibody detection or titration and its comparison to the current reference method (RFFIT). The data collected during validation of the test in a multicenter study are analysed to give a sound overall knowledge of the capabilities of the PLATELIA RABIES II, for instance specificity, linearity, accuracy, precision, detection limit and quantitation limit. To this aim, human serum samples from a total of 1348 vaccinated or non-vaccinated people were tested in parallel using the new ELISA and the RFFIT for the presence of anti-rabies antibodies. Data generated indicate a linear relationship across the range of titration between the two methods. The sensitivity reaches 98.6% and the specificity 99.4%. This study indicates that this new ELISA test is as sensitive and specific as the current standardized reference method. The method is simple, safe, rapid and can be considered as a useful alternative to the neutralisation test. PMID:17224214

  13. Multicenter Guidelines | Division of Cancer Prevention

    Cancer.gov

    A Lead Organization conducting multi-institutional studies in the consortium has specific responsibilities in order to comply with the DCP Multicenter Guidelines. The Lead Organization is responsible for the following at all Participating Organizations as well as the Lead Organization: |

  14. Risk factors in patients with oral pemphigus vulgaris: a case-control study.

    PubMed

    Bakhshi, Mahin; Manifar, Soheila; Azizi, Nemat; Asayesh, Hamid; Mansouri, Parvin; Nasiri, Soheila; Hashemi, Zeynab; Mehdipour, Aida

    2016-01-01

    Pemphigus vulgaris (PV) is considered a chronic disease with a potentially fatal outcome. Studies have suggested that environmental factors and personal habits play an important role in the pathogenesis of PV, but more studies are required to elaborate their connection to the disease. The goal of this multicenter case-control study was to determine some of the environmental factors related to PV. Cases (n = 99) were patients with PV, and controls (n = 198) were individuals who did not have PV. Data about demographics, history, clinical findings, occupational exposures to pesticides, smoking status, number of births (parity), herpes simplex virus (HSV) infection, and fast food consumption were collected using a structured questionnaire. Chi-square and logistic regression analyses were used for data analysis. Univariate logistic regression analysis indicated that the statistically significant factors related to PV were infection with HSV in recent weeks (odds ratio [OR], 3.35; 95% confidence interval [CI], 1.75-6.43), parity (OR, 0.50; 95% CI, 0.39-0.63), and lack of occupational exposure to pesticides (OR, 0.36; 95% CI, 0.21-0.60). Multivariate analysis revealed that significant factors were cessation of smoking (adjusted odds ratio [AOR], 4.36; 95% CI, 1.50-12.66), HSV infection (AOR, 2.91; 95% CI, 1.47-5.75), and lack of occupational exposure to pesticides (AOR, 0.35; 95% CI, 0.20-0.63). The findings indicated that cessation of smoking and HSV infection in recent weeks are risk factors for PV, while lack of occupational exposure to pesticides and increasing parity (a greater number of births) are protective factors against PV. PMID:27148665

  15. Infliximab-induced autoantibodies: a multicenter study.

    PubMed

    Vaz, João Luiz Pereira; Fernandes, Vander; Nogueira, Felipe; Arnóbio, Adriano; Levy, Roger A

    2016-02-01

    The purpose of this study was to assess autoantibody incidence in patients treated with infliximab for various diseases, and the development of autoimmune diseases using a multicenter, longitudinal, open-label, phase IV observational study. All patients received anti-tumor necrosis factor (anti-TNF) according to local treatment guidelines. The autoantibodies assessed before and after infliximab treatment were ANA, anti-Sm, anti-dsDNA, anticardiolipin IgM/IgG, anti-Scl70, anti-centromere B, anti-chromatin, anti-ribosomal P, anti-Sm-RNP, anti-RNP A, anti-RNP 68 kD, anti-La/SSB, anti-Ro/SSA 52 kD and 60 kD, and anti-Jo1. ANA was determined by indirect immunofluorescence on HEp-2 cells (INOVA); the remaining was assessed using BioPlexTM 2200. The Fisher exact test, Wilcoxon test, and the McNemar were used when appropriate.Two hundred eighty-six patients were included (139 with rheumatoid arthritis, 77 with ankylosing spondylitis, 29 with inflammatory bowel disease, 27 with psoriatic arthritis, and 14 with psoriasis), 167 females and 119 males, with mean age of 46.3 years. Subjects received at least five infusions of infliximab (6-month treatment). A significant difference was observed in antinuclear antibody (ANA) detection between samplings (p = 0.001). Among patients that had ANA before treatment (n = 92), six became ANA-negative, 48 had increased titers, 29 maintained, and nine decreased titers after treatment; a total of 186 patients had a positive ANA after treatment. Fine speckled nuclear pattern was most commonly observed (both before and after infliximab treatment). The number of patients with anti-dsDNA had a statistically significant increase (p = 0.003). No significant differences were noted for anticardiolipin and the remaining autoantibodies tested. Among the 286 patients included in the study, only one (0.35 %) showed clinical signs of drug-induced lupus, presenting elevated ANA and anti-dsDNA titers that normalized once treatment was

  16. Methodological Issues on Planning and Running the Brazilian Multicenter Study on Preterm Birth

    PubMed Central

    Lajos, Giuliane J.; Tedesco, Ricardo P.; Passini, Renato; Dias, Tabata Z.; Nomura, Marcelo L.; Rehder, Patrícia M.; Haddad, Samira M.; Sousa, Maria H.; Cecatti, Jose G.; Brazilian Multicenter Study on Preterm Birth Study Group

    2015-01-01

    Objectives. Assuming that the occurrence of preterm births and their maternal and neonatal associated conditions in Brazil are not completely known, a multicenter study was proposed. The purpose of this paper is to describe the methods used, its processes, achievements, and challenges. Study Design. A multicenter cross-sectional study on preterm births in Brazilian facilities plus a nested case-control study to assess their associated factors. A description of all steps of planning and implementing such a nationwide study, including strategies for dealing with problems arising during the process, is presented. Results. 20 referral hospitals in different regions of Brazil participated in the study. A detailed questionnaire for data collection, an electronic platform for data transcription and monitoring, research materials, and specific monitoring tools were developed; then data management and analyses were performed. Finally, we got information on 4,150 preterm births and 1,146 term births. Conclusions. This study represented the first step of a planned comprehensive assessment of preterm birth in Brazil, with detailed information that will lead to several analyses and further studies, bringing the knowledge to improve screening, diagnosis, and treatment practices in maternal and perinatal health with the final purpose of reducing the burden of this condition in the country. PMID:25759862

  17. Performance of Disease Risk Score Matching in Nested Case-Control Studies: A Simulation Study.

    PubMed

    Desai, Rishi J; Glynn, Robert J; Wang, Shirley; Gagne, Joshua J

    2016-05-15

    In a case-control study, matching on a disease risk score (DRS), which includes many confounders, should theoretically result in greater precision than matching on only a few confounders; however, this has not been investigated. We simulated 1,000 hypothetical cohorts with a binary exposure, a time-to-event outcome, and 13 covariates. Each cohort comprised 2 subcohorts of 10,000 patients each: a historical subcohort and a concurrent subcohort. DRS were estimated in the historical subcohorts and applied to the concurrent subcohorts. Nested case-control studies were conducted in the concurrent subcohorts using incidence density sampling with 2 strategies-matching on age and sex, with adjustment for additional confounders, and matching on DRS-followed by conditional logistic regression for 9 outcome-exposure incidence scenarios. In all scenarios, DRS matching yielded lower average standard errors and mean squared errors than did matching on age and sex. In 6 scenarios, DRS matching also resulted in greater empirical power. DRS matching resulted in less relative bias than did matching on age and sex at lower outcome incidences but more relative bias at higher incidences. Post-hoc analysis revealed that the effect of DRS model misspecification might be more pronounced at higher outcome incidences, resulting in higher relative bias. These results suggest that DRS matching might increase the statistical efficiency of case-control studies, particularly when the outcome is rare. PMID:27189330

  18. Lateralization in cluster headache: a Nordic multicenter study.

    PubMed

    Meyer, Eva Laudon; Laurell, Katarina; Artto, Ville; Bendtsen, Lars; Linde, Mattias; Kallela, Mikko; Tronvik, Erling; Zwart, John-Anker; Jensen, Rikke M; Hagen, Knut

    2009-08-01

    A slight predominance of cluster pain on the right side has been reported in several studies. The aim of this large retrospective Nordic multicenter study was to estimate the prevalence of right- and left-sided pain in cluster headache (CH) patients with side-locked pain, the prevalence of side shifts in episodic and chronic CH patients, and the occurrence of cranial autonomic symptoms related to pain side. Among 383 cluster patients, 55 (14%) had experienced pain side shift. Of the remaining 328 individuals without side shift, there was no significant difference between the occurrence of right-sided and left-sided pain (54 vs. 46%). The prevalence of side shift was similar for episodic and chronic CH and the occurrence of cranial autonomic symptoms was not influenced by the pain side. In conclusion, previous reports of a side difference in location of cluster pain could not be confirmed in this large Nordic sample. PMID:19495933

  19. Elliptic genera from multi-centers

    NASA Astrophysics Data System (ADS)

    Gaddam, Nava

    2016-05-01

    I show how elliptic genera for various Calabi-Yau threefolds may be understood from supergravity localization using the quantization of the phase space of certain multi-center configurations. I present a simple procedure that allows for the enumeration of all multi-center configurations contributing to the polar sector of the elliptic genera — explicitly verifying this in the cases of the quintic in {P} 4, the sextic in {W}{P} (2,1,1,1,1), the octic in {W}{P} (4,1,1,1,1) and the dectic in {W}{P} (5,2,1,1,1). With an input of the corresponding `single-center' indices (Donaldson-Thomas invariants), the polar terms have been known to determine the elliptic genera completely. I argue that this multi-center approach to the low-lying spectrum of the elliptic genera is a stepping stone towards an understanding of the exact microscopic states that contribute to supersymmetric single center black hole entropy in {N} = 2 supergravity.

  20. A re-evaluation of a case-control model with contaminated controls for resource selection studies.

    PubMed

    Rota, Christopher T; Millspaugh, Joshua J; Kesler, Dylan C; Lehman, Chad P; Rumble, Mark A; Jachowski, Catherine M B

    2013-11-01

    1. A common sampling design in resource selection studies involves measuring resource attributes at sample units used by an animal and at sample units considered available for use. Few models can estimate the absolute probability of using a sample unit from such data, but such approaches are generally preferred over statistical methods that estimate a relative probability of use. 2. The case-control model that allows for contaminated controls, proposed by Lancaster & Imbens (1996) and Lele (2009), can estimate the absolute probability of using a sample unit from use-availability data. However, numerous misconceptions have likely prevented the widespread application of this model to resource selection studies. We address common misconceptions regarding the case-control model with contaminated controls and demonstrate its ability to estimate the absolute probability of use, prevalence and parameters associated with categorical covariates from use-availability data. 3. We fit the case-control model with contaminated controls to simulated data with varying prevalence (defined as the average probability of use across all sample units) and sample sizes (n1 = 500 used and na = 500 available samples; n1 = 1000 used and na = 1000 available samples). We then applied this model to estimate the probability Ozark hellbenders (Cryptobranchus alleganiensis bishopi) would use a location within a stream as a function of covariates. 4. The case-control model with contaminated controls provided unbiased estimates of all parameters at N = 2000 sample size simulation scenarios, particularly at low prevalence. However, this model produced increasingly variable maximum likelihood estimates of parameters as prevalence increased, particularly at N = 1000 sample size scenarios. We thus recommend at least 500-1000 used samples when fitting the case-control model with contaminated controls to use-availability data. Our application to hellbender data revealed selection for locations with

  1. 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…

  2. Telomere Length and Ischemic Stroke in Women: A Nested Case-Control Study

    PubMed Central

    Schürks, Markus; Prescott, Jennifer; Dushkes, Rimma; De Vivo, Immaculata; Rexrode, Kathryn M.

    2013-01-01

    Background Telomere shortening has been implicated in cardiovascular disease. However, prospective data on the association between relative telomere length (RTL) and ischemic stroke are scarce and inconclusive. Methods We used a nested case-control design among women participating in the prospective Nurses’ Health Study. Participants provided blood samples in 1990 and were followed through 2006. Women with confirmed incident ischemic stroke were matched to controls by age, smoking, postmenopausal status, and postmenopausal hormone use. Quantitative PCR was used to determine RTL in genomic DNA extracted from peripheral blood leukocytes. Conditional logistic regression was used to determine the risk of ischemic stroke associated with RTL, using RTL quartiles and as dichotomous according to the median. Results Data on RTL were available from 504 case-control pairs. Results did not suggest an association between RTL and ischemic stroke. The odds ratio for ischemic stroke was 0.82 (95% confidence interval [CI] 0.52–1.32) comparing lowest to the highest RTL quartile and 0.90 (95% CI 0.65–1.24) comparing RTL below the median to RTL above the median. Associations were unchanged after additional adjustment for cardiovascular risk factors. Further analyses suggested an association between RTL and fatal ischemic stroke (54 case-control pairs; lowest vs. highest quartile OR=1.99, 95%CI 0.26–14.9); however, results were statistically insignificant. Conclusion In this large nested case-control study among women RTL was not associated with ischemic stroke. In light of the varying study results in the literature on the association between telomere length and stroke additional research is warranted. PMID:23521613

  3. [Orthostatic hypotension in elderly: a case-control study].

    PubMed

    Krypciak, Sébastien; Liuu, Evelyne; Minard, Aurélien; Obraztsova, Anastasia; Paillaud, Elena

    2016-01-01

    Orthostatic hypotension is common in the elderly and is often associated with increased morbidity and mortality. Compression bandages are recommended as a first-line treatment but there is little evidence of their efficacy in literature. A case-control study involving 52 patients was carried out to test the efficacy of the bandages. In the group with orthostatic hypotension, compression improved the symptoms without correcting the blood pressure readings. PMID:26805647

  4. 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. PMID:27057012

  5. Methodology Series Module 2: Case-control Studies

    PubMed Central

    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. PMID:27057012

  6. A case-control study of the effect of environmental sanitation on diarrhoea morbidity in Malawi.

    PubMed Central

    Young, B; Briscoe, J

    1988-01-01

    A case-control design has been applied in the evaluation of improved environmental sanitation on diarrhoeal diseases in rural Malawi. The study demonstrates the feasibility of using such an approach to evaluate two levels of water supply and sanitation service quickly and at moderate cost. Sample sizes would need to be increased substantially to evaluate multiple levels of service or to investigate interactions between water supply and sanitation. The results indicate that children living in families who use good quality water supplies and latrines experience 20% less diarrhoea as reported to the health clinics during the warm, rainy season. PMID:3418292

  7. A case-control study of the effect of environmental sanitation on diarrhoea morbidity in Malawi.

    PubMed

    Young, B; Briscoe, J

    1988-03-01

    A case-control design has been applied in the evaluation of improved environmental sanitation on diarrhoeal diseases in rural Malawi. The study demonstrates the feasibility of using such an approach to evaluate two levels of water supply and sanitation service quickly and at moderate cost. Sample sizes would need to be increased substantially to evaluate multiple levels of service or to investigate interactions between water supply and sanitation. The results indicate that children living in families who use good quality water supplies and latrines experience 20% less diarrhoea as reported to the health clinics during the warm, rainy season. PMID:3418292

  8. Case-control study of waterborne giardiasis in Reno, Nevada.

    PubMed

    Navin, T R; Juranek, D D; Ford, M; Minedew, D J; Lippy, E C; Pollard, R A

    1985-08-01

    An outbreak of Giardia lamblia gastroenteritis occurred in Reno, Nevada, in 1982, during which 324 laboratory-confirmed infections were reported. During the outbreak, Reno was supplied in part by surface water that was chemically coagulated, settled, and chlorinated, but was not filtered. Giardia cysts were recovered from the water supply, and a beaver infected with Giardia was found in one of the reservoirs. A case-control study indicated that, during the outbreak but not afterwards, persons with giardiasis drank more municipal water than did controls. Corrective measures, which included removing the infected beaver and increasing the chlorine concentration, were followed by a rapid decrease in reports of giardiasis. PMID:4014209

  9. 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. PMID:20806110

  10. Case-control study of statin prevention of mould infections.

    PubMed

    Thompson, Jessica N; Huycke, Mark M; Greenfield, Ronald A; Kurdgelashvili, George; Gentry, Chris A

    2011-09-01

    Invasive mould infections (IMI) are associated with significant morbidity and mortality. In vitro studies have demonstrated that hydroxymethylglutaryl-CoA (HMG-CoA) reductase inhibitors (statins) have activity against several pathogenic moulds including Zygomycetes and Aspergillus spp. The aim of our study was to determine if statin use is a preventive factor for the development of IMI. This was a retrospective case-control study of 10 United States Veterans Affairs Medical Centers that comprise the Veterans Integrated Service Network (VISN) 16. Cases with IMI and controls were identified from 2001 to 2008. Controls were matched by age, facility, history of transplantation, presence of chronic steroid use and presence of human immunodeficiency virus infection (HIV). Two hundred and thirty-eight patients were included. Independent variables associated with the development of IMI were history of solid malignant tumours (OR 2.63, 1.41-4.87) and hypertension (OR 2.29, 1.13-4.68). Statin use within 3 months of index date was not an independent variable for prevention or development of IMI. No level of exposure to a statin drug appeared to influence the development of infection. This retrospective case-control study suggests that despite evidence of in vitro activity, statins may not decrease risk of IMI. Prospective, controlled trials may be necessary to investigate any potential clinical benefit. PMID:21554419

  11. Dose-response in case-control studies.

    PubMed Central

    Berry, G

    1980-01-01

    The evidence provided by a case-control study on the association between a disease and some factor is strengthened if the extent of exposure to the factor is categorised into several groups or measured on a continuous scale. Then dose-response relationships can be estimated. The methods available are illustrated by application to data on lung cancer and chrysotile asbestos exposure from Quebec in which there were three matched controls for each case. Regression-type models were fitted assuming that the relative risk of lung cancer was linearly related to an exposure measure; a covariate, smoking, was also included in the analysis. The data were first analysed ignoring the matching and secondly taking account of the matching. The methodology for the latter analysis has only recently been developed; formerly, matched studies were of necessity analysed as unmatched. Although, in this particular example, the unmatched and matched analyses gave similar results, this is not always the case and it is argued that, now that the methodology is available, matched case-control studies should be analysed taking proper account of the matching. PMID:7441145

  12. Cancer and polluted work places: a case-control study.

    PubMed

    Kjuus, H; Lislerud, A; Lyngdal, P T; Omland, H; Stave, O; Langård, S

    1982-02-01

    The possible association between selected cancers and polluted work places has been studied in a hospital-based, case-control study. By dividing all jobs in the participants working career into "polluted" and "clean", a crude measure for the total industrial exposure a worker experiences throughout his life was established. Among 103 age-matched, case-control pairs the overall estimated relative risk (RR) for exposed subjects (greater than or equal to 10 years in a polluted work place) of developing cancer compared to nonexposed (less than 10 years in a polluted work place) was 1.1. The only subgroup where a significant difference was found between the cases and the controls was the lung cancer subgroup (RR = 4.0, p = 0.02, two-tailed). When the 30 lung cancer cases were compared to an alternative control group consisting of 60 subjects matched for age and smoking habits, an estimated RR of 4.5 was found. A moderate, but not significant association between lung cancer and definite asbestos exposure was also found (RR: 2.3). As most workers are exposed to a variety of industrial agents throughout their working careers, further development of methods for characterizing combined exposures are needed, both for retrospective and prospective purposes. PMID:7068240

  13. 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

  14. 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

  15. Effectiveness of reactive oral cholera vaccination in rural Haiti: a case-control study

    PubMed Central

    Ivers, Louise C; Hilaire, Isabelle J; Teng, Jessica E; Almazor, Charles P; Jerome, J Gregory; Ternier, Ralph; Boncy, Jacques; Buteau, Josiane; Murray, Megan B; Harris, Jason B; Franke, Molly F

    2015-01-01

    Background Between April and June 2012, a reactive cholera vaccination campaign was conducted in Haiti using an oral inactivated bivalent whole-cell vaccine (BivWC). Methods We conducted a case-control study to estimate field effectiveness of the vaccine. Cases had acute watery diarrhea, sought treatment at one of three participating cholera treatment units from October 24, 2012 through March 9, 2014, and had a stool sample positive for cholera by culture. For each case, four controls (individuals who did not seek treatment for acute watery diarrhea) were matched by location of residence, calendar time, and age. We also conducted a bias-indicator case-control study to assess the likelihood of bias in the vaccine effectiveness (VE) study. Findings During the study period, 114 eligible individuals presented with acute watery diarrhea and were enrolled. 47 were analyzed as cases in the VE case-control study and 42 as cases in the bias-indicator study. In multivariable analyses, VE was 63% [95% confidence interval (CI): 8%–85%] by self-reported vaccination and 58% [95% CI: 13%–80%] for verified vaccination. Neither self-reported nor verified vaccination was significantly associated with non-cholera diarrhea (VE: 18% [95% CI: −208%–−78%] by self-report and −21% [95%CI: −238%–57%] for verified vaccination). Interpretation BivWC oral cholera vaccine was effective in protecting against cholera in Haiti during the study period –from 4 through 24 months after vaccination. Vaccination is an important component of epidemic cholera control efforts. Funding National Institutes of Health, Delivering Oral Vaccines Effectively project, Department of Global Health and Social Medicine at Harvard Medical School. PMID:25701994

  16. 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.

  17. 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

  18. Functional Impairment in Adult Sleepwalkers: A Case-Control Study

    PubMed Central

    Lopez, Regis; Jaussent, Isabelle; Scholz, Sabine; Bayard, Sophie; Montplaisir, Jacques; Dauvilliers, Yves

    2013-01-01

    Study Objectives: To investigate the restorative quality of sleep and daytime functioning in sleepwalking adult patients in comparison with controls. Design: Prospective case-control study. Setting: Data were collected at the Sleep Disorders Center, Hôpital-Gui-de Chauliac, Montpellier, France between June 2007 and January 2011. Participants: There were 140 adult sleepwalkers (100 (median age 30 y, 55% male) in whom primary SW was diagnosed) who underwent 1 night of video polysomnography. All patients participated in a standardized clinical interview and completed a battery of questionnaires to assess clinical characteristics of parasomnia, daytime sleepiness, fatigue, insomnia, depressive and anxiety symptoms, and health-related quality of life. Results were compared with those of 100 sex- and age-matched normal controls. Interventions: N/A. Measurements and Results: Of the sleepwalkers, 22.3% presented with daily episodes and 43.5% presented with weekly episodes. Median age at sleepwalking onset was 9 y. Familial history of sleepwalking was reported in 56.6% of sleepwalkers and violent sleep related behaviors in 57.9%, including injuries requiring medical care for at least one episode in 17%. Significant associations were found between sleepwalking and daytime sleepiness, fatigue, insomnia, depressive and anxiety symptoms, and altered quality of life. Early-onset sleepwalkers had higher frequency of violent behaviors and injuries. Sleepwalkers with violent behaviors had higher frequency of sleep terrors and triggering factors, with greater alteration in health-related quality of life. Conclusion: Adult sleepwalking is a potentially serious condition that may induce violent behaviors, self-injury or injury to bed partners, sleep disruption, excessive daytime sleepiness, fatigue, and psychological distress, all of which affect health-related quality of life. Citation: Lopez R; Jaussent I; Scholz S; Bayard S; Montplaisir J; Dauvilliers Y. Functional impairment in

  19. 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

  20. Case-control association studies with matching and genomic controlling.

    PubMed

    Lee, Wen-Chung

    2004-07-01

    Family-based association studies have gained in popularity for mapping disease-susceptibility gene(s) of complex diseases. However, recruiting family controls is often more difficult than recruiting unrelated controls. The author proposes a case-control study, where the possible biases due to population stratification are controlled by matching in the design stage and by genomic controlling in the data-analytic stage. The matching is based on a set of "stratum-delineating variables," such as, race, ethnicity, nationality, ancestry, and birthplace; and the genomic controlling is based on typing a number of null markers across the genome and applying the principle of multiplicative scaling of chi-square distribution. It pays to match carefully to have a higher proportion of correctly matched sets, as computer simulation showed that this would increase the power of the study. If matching is crude, one loses power but still has the correct type I error rate after genomic controlling. Power studies showed that the numbers of affected subjects required for the pair-matched study are comparable to those required by the case-parents design, if the study was conducted in a homogeneous population. As the (control-to-case) matching ratio increases, the number of affected subjects required decreases. With matching ratio tending toward infinity, the number required shrinks roughly by half. The case-control study with matching and genomic controlling frees us from family bondage, and the genetic problem as complicated as mapping genes can now be studied using simple epidemiologic methods. PMID:15185398

  1. Management of Pneumothorax in Emergency Medicine Departments: Multicenter Trial

    PubMed Central

    Ince, Abdulkadir; Ozucelik, Dogac Niyazi; Avci, Akkan; Nizam, Ozgur; Dogan, Halil; Topal, Mehmet Ali

    2013-01-01

    Background: Pneumothorax is common and life-threatening clinical condition which may require emergency treatment in Emergency Medicine Departments. Objectives: We aimed to reveal the epidemiological analysis of the patients admitted to the Emergency Department with pneumothorax. Material and Methods: This case-control and multi-center study was conducted in the patients treated with the diagnosis of pneumothorax between 01.01.2010-31.12.2010. Patient data were collected from hospital automation system. According to the etiology of the pneumothorax, study groups were arranged like spontaneous pneumothorax and traumatic pneumothorax. Results: 82.2% (n = 106) of patients were male and 17.8% (n = 23) of patients were female and mean age were 31.3 ± 20,2 (Minimum: 1, Maximum: 87). 68.2% (n = 88) of patients were spontaneous pneumothorax (61.36%, n=79 were primary spontaneous pneumothorax) and 31.8% (n = 41) of patients were traumatic pneumothorax (21.95% were iatrogenic pneumothorax). Main complaint is shortness of breath (52.3%, n=67) and 38% (n=49) of patients were smokers. Posteroanterior (PA) Chest X-Ray has been enough for 64.3% (n = 83) of the patients' diagnosis. Tube thoracostomy is applied to 84.5% (n = 109) of patients and surgery is applied to 9.3% (n = 12) of patients and 6.2% (n = 8) of patients were discharged with conservative treatment. Spontaneous pneumothorax showed statistically significant high recurrence compared with traumatic pneumothorax (P = 0.007). 4.65% of (n = 6) patients died. The average age of those who died (9.3 ± 19.9), statistically were significantly lower the mean age of living patients (32.4 ± 19.7) (t test, P = 0,006). 83.33% of the patients who died were neonatals and in the 0-1 years age group, and five of these patients were secondary spontaneous pneumothorax, and one of these patients were iatrogenic pneumothorax due to mechanical ventilation. Conclusions: Pneumothorax in adults can be treated by tube thoracostomy or

  2. Direct assessment of multiple testing correction in case-control association studies with related individuals.

    PubMed

    Wang, Zuoheng

    2011-01-01

    Genome-wide association studies typically test large numbers of genetic variants in association with trait values. It is well known that linkage disequilibrium (LD) between nearby markers tends to introduce correlation among association tests. Failure to properly adjust for multiple comparisons can lead to false-positive results or missing true-positive signals. The Bonferroni correction is generally conservative in the presence of LD. The permutation procedure, although has been widely employed to adjust for correlated tests, is not applicable when related individuals are included in case-control samples. With related individuals, the dependence among relatives' genotypes can also contribute to the correlation between tests. We present a new method P(norm) to correct for multiple hypothesis testing in case-control association studies in which some individuals are related. The adjustment with P(norm) simultaneously accounts for two sources of correlations of the test statistics: (1) LD among genetic markers (2) dependence among genotypes across related individuals. Using simulated data based on the International HapMap Project, we demonstrate that it has better control of type I error and is more powerful than some of the recently developed methods. We apply the method to a genome-wide association study of alcoholism in the GAW 14 COGA data set and detect genome-wide significant association. PMID:21181898

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

    PubMed Central

    Schmidt-Pokrzywniak, Andrea; Jöckel, Karl-Heinz; Bornfeld, Norbert; Stang, Andreas

    2004-01-01

    Background Although a rare disease, uveal melanoma is the most common primary intraocular malignancy in adults, with an incidence rate of up to 1.0 per 100,000 persons per year in Europe. Only a few consistent risk factors have been identified for this disease. We present the study design of an ongoing incident case-control study on uveal melanoma (acronym: RIFA study) that focuses on radiofrequency radiation as transmitted by radio sets and wireless telephones, occupational risk factors, phenotypical characteristics, and UV radiation. Methods/Design We conduct a case-control study to identify the role of different exposures in the development of uveal melanoma. The cases of uveal melanoma were identified at the Division of Ophthalmology, University of Essen, a referral centre for tumours of the eye. We recruit three control groups: population controls, controls sampled from those ophthalmologists who referred cases to the Division of Ophthalmology, University of Duisburg-Essen, and sibling controls. For each case the controls are matched on sex and age (five year groups), except for sibling controls. The data are collected from the study participants by short self-administered questionnaire and by telephone interview. During and at the end of the field phase, the data are quality-checked. To estimate the effect of exposures on uveal melanoma risk, we will use conditional logistic regression that accounts for the matching factors and allows to control for potential confounding. PMID:15318944

  4. Unified Analysis of Secondary Traits in Case-Control Association Studies

    PubMed Central

    Ghosh, Arpita; Wright, Fred A.; Zou, Fei

    2013-01-01

    It has been repeatedly shown that in case-control association studies, analysis of a secondary trait which ignores the original sampling scheme can produce highly biased risk estimates. Although a number of approaches have been proposed to properly analyze secondary traits, most approaches fail to reproduce the marginal logistic model assumed for the original case-control trait and/or do not allow for interaction between secondary trait and genotype marker on primary disease risk. In addition, the flexible handling of covariates remains challenging. We present a general retrospective likelihood framework to perform association testing for both binary and continuous secondary traits which respects marginal models and incorporates the interaction term. We provide a computational algorithm, based on a reparameterized approximate profile likelihood, for obtaining the maximum likelihood (ML) estimate and its standard error for the genetic effect on secondary trait, in presence of covariates. For completeness we also present an alternative pseudo-likelihood method for handling covariates. We describe extensive simulations to evaluate the performance of the ML estimator in comparison with the pseudo-likelihood and other competing methods. PMID:24409003

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

    PubMed

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

    2007-07-01

    Cases of illness were reported to Hertsmere Borough Council among attendees of a children's charity event in June 2006. Initial laboratory investigation identified Salmonella Enteritidis PT13a as a possible cause of the outbreak. We carried out an unmatched case-control investigation. The population at risk included all individuals who attended the event. Self-completion questionnaires were sent to 53 presumptive cases and 212 randomly selected potential controls. Information was available for 49 cases and 128 controls (overall response rate=75%). We calculated odds ratios from single and multivariable analysis and tested for all two-way interactions. Risk factors for diarrhoea were eating egg mayonnaise bagels (OR=34.1, 95%CI 10.5 - 111.3) and drinking apple juice (OR=16.1, 95% CI 3.5 - 74.2). There was weak statistical evidence to suggest that the risk of diarrhoea after eating egg mayonnaise bagels was greater in the afternoon. No food samples were available to confirm which food item might have caused this outbreak. Eggs from Spain were used by the caterer. The ecology of salmonella, experience from previous outbreaks and epidemiological findings from this case-control investigation suggest that the most likely cause of the outbreak was contaminated eggs. PMID:17991411

  6. Risk Factors of Streptococcus suis Infection in Vietnam. A Case-Control Study

    PubMed Central

    Ho, Dang Trung Nghia; Le, Thi Phuong Tu; Wolbers, Marcel; Cao, Quang Thai; Nguyen, Van Minh Hoang; Tran, Vu Thieu Nga; Le, Thi Phuong Thao; Nguyen, Hoan Phu; Tran, Thi Hong Chau; Dinh, Xuan Sinh; To, Song Diep; Hoang, Thi Thanh Hang; Hoang, Truong; Campbell, James; Nguyen, Van Vinh Chau; Nguyen, Tran Chinh; Nguyen, Van Dung; Ngo, Thi Hoa; Spratt, Brian G.; Tran, Tinh Hien; Farrar, Jeremy; Schultsz, Constance

    2011-01-01

    Background Streptococcus suis infection, an emerging zoonosis, is an increasing public health problem across South East Asia and the most common cause of acute bacterial meningitis in adults in Vietnam. Little is known of the risk factors underlying the disease. Methods and Findings A case-control study with appropriate hospital and matched community controls for each patient was conducted between May 2006 and June 2009. Potential risk factors were assessed using a standardized questionnaire and investigation of throat and rectal S. suis carriage in cases, controls and their pigs, using real-time PCR and culture of swab samples. We recruited 101 cases of S. suis meningitis, 303 hospital controls and 300 community controls. By multivariate analysis, risk factors identified for S. suis infection as compared to either control group included eating “high risk” dishes, including such dishes as undercooked pig blood and pig intestine (OR1 = 2.22; 95%CI = [1.15–4.28] and OR2 = 4.44; 95%CI = [2.15–9.15]), occupations related to pigs (OR1 = 3.84; 95%CI = [1.32–11.11] and OR2 = 5.52; 95%CI = [1.49–20.39]), and exposures to pigs or pork in the presence of skin injuries (OR1 = 7.48; 95%CI = [1.97–28.44] and OR2 = 15.96; 95%CI = [2.97–85.72]). S. suis specific DNA was detected in rectal and throat swabs of 6 patients and was cultured from 2 rectal samples, but was not detected in such samples of 1522 healthy individuals or patients without S. suis infection. Conclusions This case control study, the largest prospective epidemiological assessment of this disease, has identified the most important risk factors associated with S. suis bacterial meningitis to be eating ‘high risk’ dishes popular in parts of Asia, occupational exposure to pigs and pig products, and preparation of pork in the presence of skin lesions. These risk factors can be addressed in public health campaigns aimed at preventing S. suis infection

  7. 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

  8. [Occupational risks for laryngeal cancer: a case-control study].

    PubMed

    Sartor, Sergio Guerra; Eluf-Neto, José; Travier, Noemie; Wünsch Filho, Victor; Arcuri, Arline Sydneia Abel; Kowalski, Luís Paulo; Boffetta, Paolo

    2007-06-01

    The most solidly established risk factors for laryngeal cancer are tobacco and alcohol. As for occupational factors, the only established carcinogen is exposure to strong inorganic acid mists. However, asbestos, pesticides, paints, gasoline, diesel engine emissions, dusts, and other factors have been reported in the literature as occupational agents that increase the risk of laryngeal cancer. A hospital-based case-control study was conducted to investigate occupational risk factors for laryngeal cancer. Detailed data on smoking, alcohol consumption, and occupational history were collected for 122 laryngeal cancers and 187 controls matched by frequency (according to sex and age). Laryngeal cancer was associated with exposure to respirable free crystalline silica (OR = 1.83; 95%CI: 1.00-3.36), soot (from coal, coke, fuel oil, or wood) (odds ratio - OR = 1.78; 95% confidence interval - 95%CI: 1.03-3.03), fumes (OR = 2.55; 95%CI: 1.14-5.67), and live animals (OR = 1.80; 95%CI: 1.02-3.19). PMID:17546338

  9. Occupational factors associated with astrocytomas: a case-control study

    SciTech Connect

    Olin, R.G.; Ahlbom, A.; Lindberg-Navier, I.; Norell, S.E.; Spaennare, B.

    1987-01-01

    The most malignant form of all brain tumors is the supratentorial astrocytoma. Little is known about its etiology, but exogenous factors have been blamed. In this case-control study, 78 astrocytoma patients have been compared with 197 clinical and 92 population controls. An extensive questionnaire was used to gather information about occupational and residential environment exposure. Inquiries concerning groups of or individual chemicals elicited low rates of affirmative response, with negligible differences between cases and controls. However, the questions working at an airfield and living near a petrochemical plant indicated elevated risks in comparison with both control groups; so too did living near a municipal sewage treatment plant. These results focus attention on exposure to organic compounds and should be considered together with similar findings in current research. No other occupation, branch of industry, or vicinity questions showed differences between cases and controls, with the exception of living in the neighborhood of a paper mill or a saw mill, which gave moderately increased relative risks. A separate report gives the results from the nonoccupational part of the study.

  10. Thrombophilias and Pregnancy Complications: A Case-Control Study

    PubMed Central

    Giovanni, Larciprete; Antonio, Angelucci Piero; Danilo, Celleno; Stefano, Gioia; Therese, Deaibess; Elisabetta, Romanini Maria; Letizia, Brienza; Elio, Cirese; Domenico, Arduini

    2007-01-01

    Inherited thrombophilia is believed to be a multiple gene disease with more than one defect. We wanted to determine the association between single thrombophilic patterns and a variety of pregnancy diseases. 301 pregnant women were recruited for the present case-control study and were divided into two groups: A group (176 controls) and B group (125 cases). Patients belonging to the B group had one of the following: severe preeclampsia, HELLP syndrome, gestational hypertension, fetal growth restriction (FGR), intrauterine death, abruptio placentae, placenta previa, disseminated intravascular coagulopathy (DIC) and preterm labour. To detect MTHFR A1298C, MTHFR C677T, Factor V Leiden, PAI-1, Mutant Prothrombin G20210A, an inverse hybridization technology was used. Plasma homocysteine, Antithrombin III and protein levels S were determined. A modified functional activated protein C resistance was assayed. MTHFR C677T and hyperhomocysteinemia were more numerous than other thrombophilias. Deficiency in AT III was significantly linked with preeclampsia (Pearson Index and p value: 0.131 and 0.022, respectively) and disseminated intravascular coagulopathy (Pearson Index and p value: 0.138 and 0.016 respectively). Activated Protein C resistance was related to abruptio placentae (Pearson Index and p value: 0.159 and 0.005 respectively). Apart from the linkage between AT III deficiency and the occurrence of preeclampsia and disseminated intravascular coagulopathy, we obtained findings in contrast to some literature. In our case series, no association of preeclampsia with Factor V Leiden or with prothrombin gene mutation was found. PMID:23675040

  11. 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

  12. Micronutrients and oral clefts: a case-control study.

    PubMed

    McKinney, C M; Chowchuen, B; Pitiphat, W; Derouen, T; Pisek, A; Godfrey, K

    2013-12-01

    Little is known about oral clefts in developing countries. We aimed to identify micronutrient-related and environmental risk factors for oral clefts in Thailand. We tested hypotheses that maternal exposure during the periconceptional period to multivitamins or liver consumption would decrease cleft lip with or without cleft palate (CL ± P) risk and that menstrual regulation supplements would increase CL ± P risk. We conducted a multisite hospital-based case-control study in Thailand. We enrolled cases with CL ± P and 2 live births as controls at birth from the same hospital. Mothers completed a questionnaire. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Eighty-six cases and 172 controls were enrolled. Mothers who took a vitamin (adjusted OR, 0.39; 95% CI: 0.16, 0.94) or ate liver (adjusted OR, 0.26; 95% CI: 0.12, 0.57) were less likely than those who did not to have an affected child. Mothers who took a menstrual regulation supplement were more likely than mothers who did not to have an affected child. Findings did not differ for infants with a family history of other anomalies or with isolated CL ± P. If replicated, our finding that liver decreases CL ± P risk could offer a low-cost primary prevention strategy. PMID:24097855

  13. A case-control study of asthma and ovarian cancer.

    PubMed

    Elmasri, Wafic M; Tran, Therese H; Mulla, Zuber D

    2010-01-01

    Epidemiologic studies have found inverse associations between allergy and the development of certain tumors. The authors sought to determine if there was an association between asthma and ovarian cancer. A case-control study was conducted using Florida hospital data (year 2001). Discharge diagnoses were coded using the ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification). Cases were 1,582 women whose principal discharge diagnosis was a malignant neoplasm of the ovary. Two control series were used: 4,744 women whose principal diagnosis was an upper limb bone fracture, and 21,830 women whose principal diagnosis was an acute myocardial infarction. Odds ratios (ORs) adjusted for age, race-ethnicity, Medicaid status, obesity, and smoking were calculated. Cases were 30% less likely than fracture control to be asthmatics (adjusted OR = 0.70, 95% confidence interval [CI]: 0.49-0.99, p = .04). Similarly, cases when compared to acute myocardial infarction controls were significantly less likely to have asthma (adjusted OR = 0.62, 95% CI: 0.45-0.87, p = .005). The results of this statewide exploratory study suggest that individuals with asthma may have a lower risk of developing ovarian cancer than nonasthmatics. PMID:20439229

  14. Mind wandering and driving: responsibility case-control study

    PubMed Central

    Orriols, Ludivine; M’Bailara, Katia; Laborey, Magali; Contrand, Benjamin; Ribéreau-Gayon, Régis; Masson, Françoise; Bakiri, Sarah; Gabaude, Catherine; Fort, Alexandra; Maury, Bertrand; Lemercier, Céline; Cours, Maurice; Bouvard, Manuel-Pierre; Lagarde, Emmanuel

    2012-01-01

    Objective To assess the association between mind wandering (thinking unrelated to the task at hand) and the risk of being responsible for a motor vehicle crash. Design Responsibility case-control study. Setting Adult emergency department of a university hospital in France, April 2010 to August 2011. Participants 955 drivers injured in a motor vehicle crash. Main outcome measures Responsibility for the crash, mind wandering, external distraction, negative affect, alcohol use, psychotropic drug use, and sleep deprivation. Potential confounders were sociodemographic and crash characteristics. Results Intense mind wandering (highly disrupting/distracting content) was associated with responsibility for a traffic crash (17% (78 of 453 crashes in which the driver was thought to be responsible) v 9% (43 of 502 crashes in which the driver was not thought to be responsible); adjusted odds ratio 2.12, 95% confidence interval 1.37 to 3.28). Conclusions Mind wandering while driving, by decoupling attention from visual and auditory perceptions, can jeopardise the ability of the driver to incorporate information from the environment, thereby threatening safety on the roads. PMID:23241270

  15. Fluoride exposure and childhood osteosarcoma: a case-control study.

    PubMed Central

    Gelberg, K H; Fitzgerald, E F; Hwang, S A; Dubrow, R

    1995-01-01

    OBJECTIVES. This study tests the hypothesis that fluoride exposure in a nonoccupational setting is a risk factor for childhood osteosarcoma. METHODS. A population-based case-control study was conducted among residents of New York State, excluding New York City. Case subjects (n = 130) were diagnosed with osteosarcoma between 1978 and 1988, at age 24 years or younger. Control subjects were matched to case subjects on year of birth and sex. Exposure information was obtained by a telephone interview with the subject, parent, or both. RESULTS. Based on the parents' responses, total lifetime fluoride exposure was not significantly associated with osteosarcoma among all subjects combined or among females. However, a significant protective trend was observed among males. Protective trends were observed for fluoridated toothpaste, fluoride tablets, and dental fluoride treatments among all subjects and among males. Based on the subjects' responses, no significant associations between fluoride exposure and osteosarcoma were observed. CONCLUSIONS. Fluoride exposure does not increase the risk of osteosarcoma and may be protective in males. The protective effect may not be directly due to fluoride exposure but to other factors associated with good dental hygiene. There is also biologic plausibility for a protective effect. PMID:7503344

  16. Case-control study on risk factors associated with fibrocalculous pancreatic diabetes.

    PubMed

    Vannasaeng, S; Nitiyanant, W; Vichayanrat, A

    1988-12-01

    We investigated the relation between fibrocalculous pancreatic diabetes and cassava consumption in a case-control study, in which 31 cases of pancreatic diabetes were compared with 45 non-diabetic control subjects who had no pancreatic calcification. Risk of diabetes was not related to cassava consumption. We also observed no increased risk of fibrocalculous pancreatic diabetes associated with alcohol consumption, history of gallbladder and biliary tract diseases, ascariasis, and family history of diabetes. Lower monthly income, farmer occupation, rural residence, and low BMI were significantly (p less than 0.05) related to pancreatic diabetes. Our data suggest that consumption of cassava may not be an important risk factor for pancreatic diabetes. With limited sample size, however, cassava consumption could not be excluded as one possible cause of fibrocalculous pancreatic diabetes. PMID:2976643

  17. Multicenter mapping of structural network alterations in autism.

    PubMed

    Valk, Sofie L; Di Martino, Adriana; Milham, Michael P; Bernhardt, Boris C

    2015-06-01

    Autism spectrum disorders (ASD) are a group of neurodevelopmental conditions primarily characterized by abnormalities in social cognition. Abundant previous functional MRI studies have shown atypical activity in networks encompassing medial prefrontal cortex (mPFC) and medial parietal regions corresponding to posterior cingulate cortex and precuneus (PCC/PCU). Conversely, studies assessing structural brain anomalies in ASD have been rather inconsistent. The current work evaluated whether structural changes in ASD can be reliability detected in a large multicenter dataset. Our comprehensive structural MRI framework encompassed cortical thickness mapping and structural covariance analysis based on three independent samples comprising individuals with ASD and controls (n = 220), selected from the Autism Brain Imaging Data Exchange open-access database. Surface-based analysis revealed increased cortical thickness in ASD relative to controls in mPFC and lateral prefrontal cortex. Clusters encompassing mPFC were embedded in altered inter-regional covariance networks, showing decreased covariance in ASD relative to controls primarily to PCC/PCU and inferior parietal regions. Cortical thickness increases and covariance reductions in ASD were consistent, yet of variable effect size, across the different sites evaluated and measurable both in children and adults. Our multisite study shows regional and network-level structural alterations in mPFC in ASD that, possibly, relate to atypical socio-cognitive functions in this condition. PMID:25727858

  18. The relationship between parenting, family interaction and childhood dental caries: a case-control study.

    PubMed

    de Jong-Lenters, M; Duijster, D; Bruist, M A; Thijssen, J; de Ruiter, C

    2014-09-01

    The aim of this case-control study was to explore the relationship between parenting practices, parent-child interaction and childhood dental caries, using a sample of 5-8-year old children from the Netherlands. Cases were defined as children with four or more decayed, missing or filled teeth and controls were caries free. Cases (n = 28) and controls (n = 26) were recruited from a referral centre for paediatric dental care and a general dental practice, respectively. Parenting practices and parent-child interactions of the child's primary caregiver were observed using Structured Interaction Tasks and subsequently rated on seven dimensions: positive involvement, encouragement, problem-solving, discipline, monitoring, coercion and interpersonal atmosphere. All Structured Interaction Tasks were videotaped, and coded by trained and calibrated observers blind to the dental condition. Differences in parenting dimensions between cases and controls were analysed using multivariate analysis of variance, independent samples T-tests, χ(2)-tests and multiple logistic regression analyses. Controls had significantly higher scores on the dimensions positive involvement, encouragement, problem-solving and interpersonal atmosphere, compared to cases. Parents of controls were also less likely to show coercive behaviours. These associations remained statistically significant after adjustment for the mother's education level, tooth brushing frequency and the frequency of consuming sugary foods and drinks, except for coercion. There was no significant difference in discipline between cases and controls. In conclusion, this case-control study found a significant relationship between parenting practices, parent-child interaction quality and childhood dental caries. Our findings suggest that parenting practices may be an important factor to consider in caries preventive programs. PMID:24980791

  19. 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

  20. Determinants of Brushite Stone Formation: A Case-Control Study

    PubMed Central

    Siener, Roswitha; Netzer, Linda; Hesse, Albrecht

    2013-01-01

    Purpose The occurrence of brushite stones has increased during recent years. However, the pathogenic factors driving the development of brushite stones remain unclear. Methods Twenty-eight brushite stone formers and 28 age-, sex- and BMI-matched healthy individuals were enrolled in this case-control study. Anthropometric, clinical, 24 h urinary parameters and dietary intake from 7-day weighed food records were assessed. Results Pure brushite stones were present in 46% of patients, while calcium oxalate was the major secondary stone component. Urinary pH and oxalate excretion were significantly higher, whereas urinary citrate was lower in patients as compared to healthy controls. Despite lower dietary intake, urinary calcium excretion was significantly higher in brushite stone patients. Binary logistic regression analysis revealed pH>6.50 (OR 7.296; p = 0.035), calcium>6.40 mmol/24 h (OR 25.213; p = 0.001) and citrate excretion <2.600 mmol/24 h (OR 15.352; p = 0.005) as urinary risk factors for brushite stone formation. A total of 56% of patients exhibited distal renal tubular acidosis (dRTA). Urinary pH, calcium and citrate excretion did not significantly differ between patients with or without dRTA. Conclusions Hypercalciuria, a diminished citrate excretion and an elevated pH turned out to be the major urinary determinants of brushite stone formation. Interestingly, urinary phosphate was not associated with urolithiasis. The increased urinary oxalate excretion, possibly due to decreased calcium intake, promotes the risk of mixed stone formation with calcium oxalate. Neither dietary factors nor dRTA can account as cause for hypercalciuria, higher urinary pH and diminished citrate excretion. Further research is needed to define the role of dRTA in brushite stone formation and to evaluate the hypothesis of an acquired acidification defect. PMID:24265740

  1. Risk Factors for Pancreatic Cancer: Case-Control Study

    PubMed Central

    Hassan, Manal M.; Bondy, Melissa L.; Wolff, Robert A.; Abbruzzese, James L.; Vauthey, Jean-Nicolas; Pisters, Peter W.; Evans, Douglas B.; Khan, Rabia; Chou, Ta-Hsu; Lenzi, Renato; Jiao, Li; Li, Donghui

    2008-01-01

    OBJECTIVES Although cigarette smoking is the most well-established environmental risk factor for pancreatic cancer, the interaction between smoking and other risk factors has not been assessed. We evaluated the independent effects of multiple risk factors for pancreatic cancer and determined whether the magnitude of cigarette smoking was modified by other risk factors in men and women. METHODS We conducted a hospital-based case-control study involving 808 patients with pathologically diagnosed pancreatic cancer and 808 healthy frequency-matched controls. Information on risk factors was collected by personal interview, and unconditional logistic regression was used to determine adjusted odds ratios (AORs) by the maximum-likelihood method. RESULTS Cigarette smoking, family history of pancreatic cancer, heavy alcohol consumption (>60 mL ethanol/day), diabetes mellitus, and history of pancreatitis were significant risk factors for pancreatic cancer. We found synergistic interactions between cigarette smoking and family history of pancreatic cancer (AOR 12.8, 95% confidence interval [CI] 1.6–108.9) and diabetes mellitus (AOR 9.3, 95% CI 2.0–44.1) in women, according to an additive model. Approximately 23%, 9%, 3%, and 5% of pancreatic cancer cases in this study were related to cigarette smoking, diabetes mellitus, heavy alcohol consumption, and family history of pancreatic cancer, respectively. CONCLUSIONS The significant synergy between these risk factors suggests a common pathway for carcinogenesis of the pancreas. Determining the underlying mechanisms for such synergies may lead to the development of pancreatic cancer prevention strategies for high-risk individuals. PMID:17764494

  2. 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

  3. Incidence and risk factors of aplastic anemia in Latin American countries: the LATIN case-control study

    PubMed Central

    Maluf, Eliane; Hamerschlak, Nelson; Cavalcanti, Alexandre Biasi; Júnior, Álvaro Avezum; Eluf-Neto, José; Falcão, Roberto Passetto; Lorand-Metze, Irene G.; Goldenberg, Daniel; Santana, Cézar Leite; de Oliveira Werneck Rodrigues, Daniela; da Motta Passos, Leny Nascimento; Rosenfeld, Luis Gastão Mange; Pitta, Marimilia; Loggetto, Sandra; Feitosa Ribeiro, Andreza A.; Velloso, Elvira Deolinda; Kondo, Andrea Tiemi; de Miranda Coelho, Erika Oliveira; Pintão, Maria Carolina Tostes; de Souza, Hélio Moraes; Borbolla, José Rafael; Pasquini, Ricardo

    2009-01-01

    Background Associations between aplastic anemia and numerous drugs, pesticides and chemicals have been reported. However, at least 50% of the etiology of aplastic anemia remains unexplained. Design and Methods This was a case-control, multicenter, multinational study, designed to identify risk factors for agranulocytosis and aplastic anemia. The cases were patients with diagnosis of aplastic anemia confirmed through biopsy or bone marrow aspiration, selected through an active search of clinical laboratories, hematology clinics and medical records. The controls did not have either aplastic anemia or chronic diseases. A total of 224 patients with aplastic anemia were included in the study, each case was paired with four controls, according to sex, age group, and hospital where the case was first seen. Information was collected on demographic data, medical history, laboratory tests, medications, and other potential risk factors prior to diagnosis. Results The incidence of aplastic anemia was 1.6 cases per million per year. Higher rates of benzene exposure (≥30 exposures per year) were associated with a greater risk of aplastic anemia (odds ratio, OR: 4.2; 95% confidence interval, CI: 1.82–9.82). Individuals exposed to chloramphenicol in the previous year had an adjusted OR for aplastic anemia of 8.7 (CI: 0.87–87.93) and those exposed to azithromycin had an adjusted OR of 11.02 (CI 1.14–108.02). Conclusions The incidence of aplastic anemia in Latin America countries is low. Although the research study centers had a high coverage of health services, the underreporting of cases of aplastic anemia in selected regions can be discussed. Frequent exposure to benzene-based products increases the risk for aplastic anemia. Few associations with specific drugs were found, and it is likely that some of these were due to chance alone. PMID:19734415

  4. Effects of heat and moisture exchangers on tracheal mucociliary clearance in laryngectomized patients: a multi-center case-control study.

    PubMed

    van den Boer, C; Muller, S H; van der Noort, V; Olmos, R A Valdés; Minni, A; Parrilla, C; Hilgers, F J M; van den Brekel, M W M; van der Baan, S

    2015-11-01

    After total laryngectomy, inspired air is no longer optimally conditioned by the upper airways. Impaired mucociliary clearance and histological changes of respiratory epithelium, such as loss of ciliated cells, have been described in laryngectomized patients. Heat and moisture exchangers (HMEs) are passive humidifiers that re-condition the inspired air. Aim of this study was to assess the effect of HMEs on tracheal epithelium and tracheal mucus transport velocity (TMV). Tracheal brush biopsies were collected in three groups of TLE patients: 21 long-term HME users, 10 non-HME users, and 16 non-HME users before and after 4-9 months HME use. Tracheal epithelium biopsies were assessed using a digital high-speed camera mounted onto a light microscope. TMV was determined by scintigraphy in the first two patient groups. Significantly more ciliated cells were found in HME users compared to non-HME users (p = 0.05). TMV was higher in HME users (median 2 mm/min; 0-7.9) compared to non-HME users (median 0.8 mm/min; 0-12.3), but this difference was not significant (p = 0.37). One-hour breathing without HME in long-term HME users did not measurably decrease TMV (p = 0.13). The long-term use of an HME restores/prevents the loss of tracheal ciliated cells. A significant improvement in TMV was not found. Short-term (one hour) detachment of an HME has no measurable effect on TMV. PMID:25338182

  5. A multicenter, case control study of risk factors for low tibial speed of sound among residents of urban areas in Turkey.

    PubMed

    Inanici-Ersöz, Fatma; Gökçe-Kutsal, Yeşim; Oncel, Sema; Eryavuz, Merih; Peker, Ozlen; Ok, Seniz

    2002-05-01

    Risk factors which have been associated with low bone mass are multifactorial and represent regional differences between and within countries. The purpose of this study was to evaluate the possible risk factors of low tibial speed of sound (tSOS), which determines cortical bone status among residents of urban regions in Ankara, Izmir, and Istanbul, in Turkey, and also to compare groups of different socioeconomic status (SES). A total of 1,026 subjects (63% women and 53% of low socioeconomic status) 40-70 years old were included in the study. Risk factors of osteoporosis were determined using the European Vertebral Osteoporosis Study (EVOS) questionnaire, and the bone status was screened by tSOS. Socioeconomic status was found to be among the major risk factors of low tSOS in our population (odds ratio 0.39, 95% confidence interval 0.26-0.58), besides the well-known risk factors such as age and gender. Therefore, we suggest that SES is an important determinant of cortical bone status. Additionally, our results confirmed the correlation between tSOS and the clinical determinants of bone mass. PMID:12120907

  6. A Multicenter Trial Defining a Serum Protein Signature Associated with Pancreatic Ductal Adenocarcinoma

    PubMed Central

    Gerdtsson, Anna S.; Malats, Núria; Säll, Anna; Real, Francisco X.; Porta, Miquel; Skoog, Petter; Persson, Helena; Wingren, Christer; Borrebaeck, Carl A. K.

    2015-01-01

    Background. Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with rapid tumor progression and poor prognosis. This study was motivated by the lack of sensitive and specific PDAC biomarkers and aimed to identify a diagnostic, serum protein signature for PDAC. Methods. To mimic a real life test situation, a multicenter trial comprising a serum sample cohort, including 338 patients with either PDAC or other pancreatic diseases (OPD) and controls with nonpancreatic conditions (NPC), was analyzed on 293-plex recombinant antibody microarrays targeting immunoregulatory and cancer-associated antigens. Results. Serum samples collected from different hospitals were analyzed and showed that (i) sampling from five different hospitals could not be identified as a preanalytical variable and (ii) a multiplexed biomarker signature could be identified, utilizing up to 10 serum markers that could discriminate PDAC from controls, with sensitivities and specificities in the 91–100% range. The first protein profiles associated with the location of the primary tumor in the pancreas could also be identified. Conclusions. The results demonstrate that robust enough serum signatures could be identified in a multicenter trial, potentially contributing to the development of a multiplexed biomarker immunoassay for improved PDAC diagnosis. PMID:26587286

  7. Lessons from Korean Capsule Endoscopy Multicenter Studies

    PubMed Central

    Kim, Kyeong Ok

    2012-01-01

    Since its development, video capsule endoscopy (VCE) introduced a new area in the study of small bowel disease. We reviewed and discussed current issues from Korean capsule endoscopy multicenter studies. Main results are as follows: First, there was no significant difference in diagnostic yield according to the method of bowel preparation. Second, VCE represents a reliable and influential screening measure in patients with chronic unexplained abdominal pain and this technique could successfully alter the clinical course especially for patients with small bowel tumor. Third, the inter-observer variation in the expert group was lower than that in trainee group. Fourth, studies about the spontaneous capsule passage after retention showed 2.5% of retention rate and the size of lumen was an important factor of spontaneous passage. We need larger scale studies on the effect of bowel preparation methods on the diagnostic yield and further studies about the learning curve or unique capsule endoscopic findings for small intestinal diseases in Korean patients. PMID:22977821

  8. Diet and gallbladder cancer: a case-control study.

    PubMed

    Pandey, M; Shukla, V K

    2002-08-01

    Cancer of the gallbladder is rare but fatal, and has an unusual geographic and demographic distribution. Gallstones and obesity have been suggested as possible risk factors. As diet is known to influence both these factors, we carried out the present study to evaluate the possible role of diet in gallbladder carcinogenesis. A case-control study involving 64 newly diagnosed cases of gallbladder cancer and 101 cases of gallstones was carried out. The dietary evaluation was carried out by the dietary recall method based on a preset questionnaire developed specifically for the present study, keeping in mind the common dietary habits prevailing in this part of the world. Odds ratios (OR) and 95% confidence interval (CI) were calculated for various dietary items. A significant reduction in odds ratio was seen with the consumption of radish (OR 0.4; 95% CI 0.17-0.94), green chilli (OR 0.45; 95% CI 0.21-0.94) and sweet potato (OR 0.33; 95% CI 0.13-0.83) among vegetables, and mango (OR 0.4; 95% CI 0.16-0.99), orange (OR; 0.45; 95% CI 0.22-0.93), melon (OR 0.3; 95% CI 0.14-0.64) and papaya (OR 0.44; 95% 0.2-0.64) among fruits. A reduction in odds was also seen with the consumption of cruciferous vegetables, beans, onion and turnip, however the difference was not statistically significant. On the other hand, an increase in the odds was observed with consumption of capsicum (OR 2.2), beef (OR 2.58), tea (OR 1.98), red chilli (OR 1.29) and mutton (OR 1.2), however the difference was statistically not significant. In conclusion, the results of the present study show a protective effect of vegetables and fruits on gallbladder carcinogenesis, but red meat (beef and mutton) was found to be associated with increased risk of gallbladder cancer. PMID:12195163

  9. Risk factors at medical school for subsequent professional misconduct: multicentre retrospective case-control study

    PubMed Central

    James, David

    2010-01-01

    Objective To determine whether there are risk factors in a doctor’s time at medical school that are associated with subsequent professional misconduct. Design Matched case-control study. Setting Records from medical schools and the General Medical Council (GMC). Participants 59 doctors who had graduated from any one of eight medical schools in the United Kingdom in 1958-97 and had a proved finding of serious professional misconduct in GMC proceedings in 1999-2004 (cases); 236 controls (four for each case) were selected by systematic sampling from matching graduation cohorts. Case-control status was revealed by the GMC after completion of data entry. Main outcome measure Odds ratios for being a “case,” with multivariable conditional logistic regression of potential risk factors including pre-admission characteristics and progress during the course. These data were obtained from anonymised copies of the students’ progress files held by their original medical schools. Results Univariate conditional logistic regression analysis found that cases were more likely to be men, to be of lower estimated social class, and to have had academic difficulties during their medical course, especially in the early years. Multivariable analysis showed that male sex (odds ratio 9.80, 95% confidence interval 2.43 to 39.44, P=0.001), lower social class (4.28, 1.52 to 12.09, P=0.006), and failure of early or preclinical examinations (5.47, 2.17 to 13.79, P<0.001) were independently associated with being a case. Conclusions This small study suggests that male sex, a lower socioeconomic background, and early academic difficulties at medical school could be risk factors for subsequent professional misconduct. The findings are preliminary and should be interpreted with caution. Most doctors with risk factors will not come before the GMC’s disciplinary panels. PMID:20423965

  10. 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

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

    PubMed Central

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

    2016-01-01

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

  12. The expression of Toll-Like Receptors (TLRs) in testicular cancer: A case control study

    PubMed Central

    Shapouri, Farnaz; Saeidi, Shaghayegh; Ashrafi Kakhki, Sara; Pouyan, Omid; Amirchaghmaghi, Elham; Aflatoonian, Reza

    2013-01-01

    Background: It has been suggested that malfunction of immune system may causes testicular cancer. Recently, our understanding of innate immune system has been expanded, by discovery of “Toll-Like Receptors” (TLRs). Some studies have shown that polymorphisms of TLR2 and 4 may affect on the risk of cancer. Also, the role of TLRs 3 and 9 have been shown in apoptosis and metastasis of cancer cells in animal models. Objective: Little information is available about the influence of innate immunity on testicular malignancy. Therefore, expression of TLRs 2, 3, 4 and 9 as main components of innate immunity has been investigated in this study. Materials and Methods: In this case control study, TLRs gene expression was examined by RT-PCR in normal testis and testicular cancer tissues. Real time quantitative PCR (Q-PCR) analysis was used to compare the relative expression of TLRs between the samples. Results: mRNAs of TLR 2, 3, 4 and 9 were expressed in all normal and cancer samples. Q-PCR reveals that cancer samples had stronger expression of these genes compared with normal ones. Conclusion: It seems that the different TLRs expression in testicular cancer cells may contribute to extensive signaling pathways involved in carcinogenesis. PMID:24639717

  13. A Single-Question Screen for REM Sleep Behavior Disorder: A Multicenter Validation Study

    PubMed Central

    Postuma, Ronald B.; Arnulf, Isabelle; Hogl, Birgit; Iranzo, Alex; Miyamoto, Tomoyuki; Dauvilliers, Yves; Oertel, Wolfgang; Ju, Yo-El; Puligheddu, Monica; Jennum, Poul; Pelletier, Amelie; Wolfson, Christina; Leu-Semenescu, Smaranda; Frauscher, Birgit; Miyamoto, Masayuki; De Cock, Valerie Cochen; Unger, Marcus M.; Stiasny-Kolster, Karin; Fantini, Maria Livia; Montplaisir, Jacques Y.

    2014-01-01

    Background Idiopathic REM sleep behavior disorder (RBD) is a parasomnia that is an important risk factor for PD and Lewy body dementia. Its prevalence is unknown. One barrier to determining prevalence is that current screening tools are too long for large-scale epidemiologic surveys. Therefore, we designed the REM Sleep Behavior Disorder Single-Question Screen (RBD1Q), a screening question for dream enactment with a simple yes/no response. Methods Four hundred and eighty-four sleep-clinic– based participants (242 idiopathic RBD patients and 242 controls) completed the screen during a multicenter case-control study. All participants underwent a polysomnogram to define gold-standard diagnosis according to standard criteria. Results We found a sensitivity of 93.8% and a specificity of 87.2%. Sensitivity and specificity were similar in healthy volunteers, compared to controls or patients, with other sleep diagnoses. Conclusions A single-question screen for RBD may reliably detect disease, with psychometric properties favorably comparable to those reported for longer questionnaires. PMID:22729987

  14. Incidence and epidemiology of anal cancer in the Multicenter AIDS Cohort Study (MACS)

    PubMed Central

    D’Souza, Gypsyamber; Wiley, Dorothy J.; Li, Xiuhong; Chmiel, Joan S.; Margolick, Joseph B.; Cranston, Ross D.; Jacobson, Lisa P.

    2014-01-01

    Objective To examine the incidence and risk factors for anal cancer in a multicenter cohort of HIV-positive and negative men who have sex with men followed between 1984 and 2006 (MACS). Methods Prospective analysis using Poisson regression and Cox proportional hazard models, and a nested case-control study using conditional logistic regression. Results There were 28 cases of anal cancer among the 6,972 men who were evaluated. The incidence rate was significantly higher in HIV-positive men than in HIV-negative men (IR= 69 vs. 14 per 100,000 person-years). Among HIV-positive men, anal cancer incidence was higher in the HAART era than the pre-HAART era (IR=137 vs. 30 per 100,000 person-years). In multivariate analysis restricted to the HAART era, anal cancer risk increased significantly with HIV infection (RH=4.7, 95%CI=1.3–17), and increasing number of unprotected receptive anal sex partners at the first three study visits (p-trend=0.03). Among HIV-positive men, current HAART use did not decrease anal cancer risk. Conclusion HIV-positive men had increased risk of anal cancer. Improved survival of HIV-positive individuals following HAART initiation may allow for sufficient time for human papillomavirus (HPV) associated anal dysplasias to develop into malignancies, thus explaining the increased incidence of anal cancer in the HAART era. PMID:18614927

  15. Multicenter pediatric emergency medicine research and Rhode Island.

    PubMed

    Chun, Thomas H

    2014-01-01

    Multicenter clinical research studies are often needed to address issues of generalizability, conditions with low incidence, adequate statistical power, and potential study bias. While pediatric research networks began work in the 1950s, and Rhode Island physicians have contributed to many of these studies, pediatric emergency medicine (PEM) collaboratives are relative newcomers. Since the mid-1990s, Rhode Island pediatricians have contributed to multicenter studies of diabetic ketoacidosis, bronchiolitis, asthma, quality of PEM care, meningitis, brief interventions for substance use disorders, point-of-care ultrasound, and pre-hospital triage protocols. In 2011, Rhode Island Hospital joined the Pediatric Emergency Care Applied Research Network, the first federally funded pediatric emergency medicine network of its kind. Its mission is to perform high quality, high impact PEM research. Since joining the network, Rhode Island Hospital has quickly become a productive and valued member of the network, portending a bright future for multicenter PEM research in the Ocean State. PMID:24400311

  16. Clostridium difficile infection after adult autologous stem cell transplantation: A multicenter study of epidemiology and risk factors

    PubMed Central

    Dufresne, Simon F.; Hanna, David B.; Labbé, Annie-Claude; Treadway, Suzanne B.; Neofytos, Dionissios; Bélanger, Sylvie; Huff, Carol Ann; Laverdière, Michel; Marr, Kieren A.

    2013-01-01

    We sought to describe the epidemiology of Clostridium difficile infection (CDI) among adult recipients of autologous hematopoietic stem cell transplantation (auto HSCT) within the first year after HSCT in centers with variable epidemiology of hyper-toxigenic strains. A multicenter, retrospective nested case-control study was conducted among 873 auto HSCT recipients at Johns Hopkins Hospital (JHH, Baltimore, MD) and Hôpital Maisonneuve-Rosemont (HMR, Montreal, Canada) between 1/2003-12/2008. Despite center differences in the prevalence of NAP-1 strains over the time period (21-43% JHH; 80-84% HMR), the 1-year incidence of CDI was similar (6.2% JHH; 5.7% HMR). The median time to infection was 11 days (interquartile range [IQR] 1 to 27). In case control analysis, the following were predictors for CDI: grade 2 or higher mucositis (odds ratio [OR]: 3.00, P=0.02) and receipt of a 4th generation cephalosporin (OR: 2.76, P=0.04). Mucositis was the strongest predictor of risk for CDI in multivariate analysis (adjusted OR [AOR]: 2.77; P=0.03). CDI is a common and early complication of auto HSCT. Treatment-related gastrointestinal mucosal damage, in addition to the potentially modifiable risk of antimicrobial exposure, influence risk for CDI early post-auto HSCT. PMID:23916741

  17. 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

  18. Cause of Emergency Department Mortality; a Case-control Study

    PubMed Central

    Alimohammadi, Hossein; Bidarizerehpoosh, Farahnaz; Mirmohammadi, Farzaneh; Shahrami, Ali; Heidari, Kamran; Sabzghabaie, Anita; Keikha, Shahram

    2014-01-01

    Introduction: Based on previous studies, cardiovascular diseases, traffic accidents, traumas and cancers are the most important etiology of mortalities in emergency departments (ED). However, contradictory findings have been reported in relation to mortality in emergency departments. Therefore, the present study was undertaken to evaluate the role of clinical factors in mortality among patients referring to an emergency department in a third-level hospital in Tehran, Iran. Methods: In the present case-control study, all the patients over 18 years of age were evaluated, referring to the ED of Imam Hossein Hospital, Tehran, Iran, from the beginning of 2009 to the end of 2010. The patients died in the ED were placed in the case group and those discharged or hospitalized in other hospital wards in the control group. Demographic data, background diseases, and the final diagnoses were recorded. Chi-squared test, multivariate logistic regression, and Pearson’s correlation coefficient were used to evaluate the relationship between the variables mentioned above and patient mortality. Results: 2907 patients (969 (59.9% male) in the case and 1938 (62.2% male) in the control groups) were evaluated. Cardiovascular diseases (39.2%), severe traumas (18.5%), and cerebrovascular accidents (17.7%) were the most frequent etiology of patient mortality in ED. Multivariate regression analysis showed that presentation with cardiovascular complaints (OR=7.3; 95% CI: 3.5-16.1; p<0.001), a history of hypertension (OR=5.4; 95% CI: 1.2-12.3; p<0.001), severe trauma (OR=4.6; 95% CI: 2.0-13.2; p<0.001), age over 60 (OR=3.8; 95% CI: 1.8-7.8; p<0.01) and a final diagnosis of renal disease (OR=3.4; 95% CI: 2.1-6.4; p<0.001) were factors that increased the odds of mortality in patients referring to the ED. Multivariate regression analysis in patients over 60 years showed that sepsis was an independent factor increasing the risk of death (OR=2.9; 95% CI: 1.3-5.9; p=0.009). A patient’s risk of

  19. Mass Spectrometry Imaging of Biological Tissue: An Approach for Multicenter Studies

    SciTech Connect

    Rompp, Andreas; Both, Jean-Pierre; Brunelle, Alain; Heeren, Ronald M.; Laprevote, Olivier; Prideaux, Brendan; Seyer, Alexandre; Spengler, Bernhard; Stoeckli, Markus; Smith, Donald F.

    2015-03-01

    Mass spectrometry imaging has become a popular tool for probing the chemical complexity of biological surfaces. This led to the development of a wide range of instrumentation and preparation protocols. It is thus desirable to evaluate and compare the data output from different methodologies and mass spectrometers. Here, we present an approach for the comparison of mass spectrometry imaging data from different laboratories (often referred to as multicenter studies). This is exemplified by the analysis of mouse brain sections in five laboratories in Europe and the USA. The instrumentation includes matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (TOF), MALDI-QTOF, MALDIFourier transform ion cyclotron resonance (FTICR), atmospheric-pressure (AP)-MALDI-Orbitrap, and cluster TOF-secondary ion mass spectrometry (SIMS). Experimental parameters such as measurement speed, imaging bin width, and mass spectrometric parameters are discussed. All datasets were converted to the standard data format imzML and displayed in a common open-source software with identical parameters for visualization, which facilitates direct comparison of MS images. The imzML conversion also allowed exchange of fully functional MS imaging datasets between the different laboratories. The experiments ranged from overview measurements of the full mouse brain to detailed analysis of smaller features (depending on spatial resolution settings), but common histological features such as the corpus callosum were visible in all measurements. High spatial resolution measurements of AP-MALDI-Orbitrap and TOF-SIMS showed comparable structures in the low-micrometer range. We discuss general considerations for planning and performing multicenter studies in mass spectrometry imaging. This includes details on the selection, distribution, and preparation of tissue samples as well as on data handling. Such multicenter studies in combination with ongoing activities for reporting guidelines, a common

  20. Intracluster correlation coefficients for the Brazilian Multicenter Study on Preterm Birth (EMIP): methodological and practical implications

    PubMed Central

    2014-01-01

    Background Cluster-based studies in health research are increasing. An important characteristic of such studies is the presence of intracluster correlation, typically quantified by the intracluster correlation coefficient (ICC), that indicate the proportion of data variability that is explained by the way of clustering. The purpose of this manuscript was to evaluate ICC of variables studied in the Brazilian Multicenter Study on Preterm Birth. Methods This was a multicenter cross-sectional study on preterm births involving 20 referral hospitals in different regions of Brazil plus a nested case–control study to assess associated factors with spontaneous preterm births. Estimated prevalence rates or means, ICC with 95% confidence intervals, design effects and mean cluster sizes were presented for more than 250 maternal and newborn variables. Results Overall, 5296 cases were included in the study (4,150 preterm births and 1,146 term births). ICC ranged from <0.001 to 0.965, with a median of 0.028. For descriptive characteristics (socio-demographic, obstetric history and perinatal outcomes) the median ICC was 0.014, for newborn outcomes the median ICC was 0.041 and for process variables (clinical management and delivery), it was 0.102. ICC was <0.1 in 78.4% of the variables and <0.3 for approximately 95% of them. Most of ICC >0.3 was found in some clinical management aspects well defined in literature such as use of corticosteroids, indicating there was homogeneity in clusters for these variables. Conclusions Clusters selected for Brazilian Multicenter Study on Preterm Birth had mainly heterogeneous findings and these results can help researchers estimate the required sample size for future studies on maternal and perinatal health. PMID:24755392

  1. 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

  2. Multiple primary tumours in women with vulvar neoplasms: a case-control study.

    PubMed Central

    Sherman, K. J.; Daling, J. R.; Chu, J.; McKnight, B.; Weiss, N. S.

    1988-01-01

    We sought to determine whether women with in situ or invasive squamous cell vulvar cancer were more likely than other women to have had a previous or concurrent tumour at other anogenital sites. One hundred and fifty-eight women with vulvar cancer were identified who were first diagnosed during 1980-1985, were ages 18-79 years at that time, and were residents of one of three counties in western Washington. Two control groups were selected: (1) from records of hospital pathology departments, a sample of 113 women with certain benign conditions of the vulva; (2) through random digit dialing, a sample of 212 women from the general population of these counties. Information on a history of other cancers, and on sexual, reproductive, medical, and demographic characteristics was collected from cases and controls in at-home interviews. Cases were more likely to report a history of other anogenital cancers than were controls, with relative risks of 3.5-29.8, depending on the type of case group and type of control. These associations were not explained by case-control differences in demographic characteristics or frequency of cervical screening. On the other hand, prior or concurrent non-anogenital cancers were equally common in cases and controls. These results support the hypothesis that the different anogenital cancers have at least one aetiology in common. PMID:3390379

  3. Msx1 Gene Variant - Its Presence in Tooth Absence - A Case Control Genetic Study

    PubMed Central

    Reddy, Naveen Admala; Adusumilli, Gopinath; Devanna, Raghu; Pichai, Saravanan; Rohra, Mayur Gobindram; Arjunan, Sharmila

    2013-01-01

    Background: Non Syndromic tooth agenesis is a congenital anomaly with significant medical, psychological and social ramifications. There is sufficient evidence to hypothesize that locus for this condition can be identified by candidate genes. The aim of this study was to test whether MSX1 671 T>C gene variant was involved in etiology of Non Syndromic tooth agenesis in Raichur Patients. Materials & Methods: Blood samples were collected with informed consent from 50 subjects having Non Syndromic tooth agenesis and 50 controls. Genomic DNA was extracted from the blood samples, Polymerase Chain Reaction was performed (PCR) and Restriction Fragment Length Polymorphism (RFLP) was performed for digestion products that were evaluated. Results: The Results showed positive correlation between MSX1671 T>C gene variant and Non Syndromic tooth agenesis in Raichur Patients. Conclusion: MSX1 671 T>C gene variant may be a good screening marker for Non Syndromic tooth agenesis in Raichur Patients . How to cite this article:Reddy NA, Adusumilli G, Devanna R, Pichai S, Rohra MG, Arjunan S. Msx1 Gene Variant - Its Presence in Tooth Absence - A Case Control Genetic Study. J Int Oral Health 2013; 5(5):20-6. PMID:24324300

  4. Case-control design as investigative approach to assessing cancer etiology: development and future perspectives.

    PubMed

    Kocic, B; Filipovic, S; Petrovic, B; Nikolic, M

    2012-01-01

    The case-control method evolved out of analyses of series of cases. The analytic form of the case-control study can be found in the 19th century medical literature, but did not appear to be viewed as a special or distinct methodology. The first modern case-control study was the Janet Lane-Claypon's study of breast cancer in 1926, but the design was used only sporadically in medicine until 1950, when 4 published casecontrol studies linked smoking and lung cancer. These 1950s studies synthesized the essential elements of the case-control comparison, produced a conceptual shift within epidemiology, and laid the foundation for the rapid development of the case-control design in the subsequent half century. The powerful consistency of these case-control studies, and the replication of their findings in later prospective studies, promoted the general acceptance of the case-control study as a scientific tool in clinical research. Newer case-control studies have benefited from the advances in design, execution and analysis since 1950s. These advances include more rigorous selection and matching of case and control population, improved interviewing techniques, location of the design within a general framework of epidemiologic strategies for relating exposure to disease, understanding of the measures of effect, and application of increasingly sophisticated statistical procedures to findings. This review traces the development and future perspectives of the case-control design to assessing cancer etiology. With illustrations drawn primarily from the literature on its use and the value of its results to unravelling the etiology of malignant diseases, we tried to explore if the case-control approach firmly ensconced in epidemiology as investigational tool and rivals in importance the more straightforward cohort approach. PMID:23033277

  5. Managing Multi-center Flow Cytometry Data for Immune Monitoring.

    PubMed

    White, Scott; Laske, Karoline; Welters, Marij Jp; Bidmon, Nicole; van der Burg, Sjoerd H; Britten, Cedrik M; Enzor, Jennifer; Staats, Janet; Weinhold, Kent J; Gouttefangeas, Cécile; Chan, Cliburn

    2014-01-01

    With the recent results of promising cancer vaccines and immunotherapy1-5, immune monitoring has become increasingly relevant for measuring treatment-induced effects on T cells, and an essential tool for shedding light on the mechanisms responsible for a successful treatment. Flow cytometry is the canonical multi-parameter assay for the fine characterization of single cells in solution, and is ubiquitously used in pre-clinical tumor immunology and in cancer immunotherapy trials. Current state-of-the-art polychromatic flow cytometry involves multi-step, multi-reagent assays followed by sample acquisition on sophisticated instruments capable of capturing up to 20 parameters per cell at a rate of tens of thousands of cells per second. Given the complexity of flow cytometry assays, reproducibility is a major concern, especially for multi-center studies. A promising approach for improving reproducibility is the use of automated analysis borrowing from statistics, machine learning and information visualization21-23, as these methods directly address the subjectivity, operator-dependence, labor-intensive and low fidelity of manual analysis. However, it is quite time-consuming to investigate and test new automated analysis techniques on large data sets without some centralized information management system. For large-scale automated analysis to be practical, the presence of consistent and high-quality data linked to the raw FCS files is indispensable. In particular, the use of machine-readable standard vocabularies to characterize channel metadata is essential when constructing analytic pipelines to avoid errors in processing, analysis and interpretation of results. For automation, this high-quality metadata needs to be programmatically accessible, implying the need for a consistent Application Programming Interface (API). In this manuscript, we propose that upfront time spent normalizing flow cytometry data to conform to carefully designed data models enables automated

  6. Managing Multi-center Flow Cytometry Data for Immune Monitoring

    PubMed Central

    White, Scott; Laske, Karoline; Welters, Marij JP; Bidmon, Nicole; van der Burg, Sjoerd H; Britten, Cedrik M; Enzor, Jennifer; Staats, Janet; Weinhold, Kent J; Gouttefangeas, Cécile; Chan, Cliburn

    2014-01-01

    With the recent results of promising cancer vaccines and immunotherapy1–5, immune monitoring has become increasingly relevant for measuring treatment-induced effects on T cells, and an essential tool for shedding light on the mechanisms responsible for a successful treatment. Flow cytometry is the canonical multi-parameter assay for the fine characterization of single cells in solution, and is ubiquitously used in pre-clinical tumor immunology and in cancer immunotherapy trials. Current state-of-the-art polychromatic flow cytometry involves multi-step, multi-reagent assays followed by sample acquisition on sophisticated instruments capable of capturing up to 20 parameters per cell at a rate of tens of thousands of cells per second. Given the complexity of flow cytometry assays, reproducibility is a major concern, especially for multi-center studies. A promising approach for improving reproducibility is the use of automated analysis borrowing from statistics, machine learning and information visualization21–23, as these methods directly address the subjectivity, operator-dependence, labor-intensive and low fidelity of manual analysis. However, it is quite time-consuming to investigate and test new automated analysis techniques on large data sets without some centralized information management system. For large-scale automated analysis to be practical, the presence of consistent and high-quality data linked to the raw FCS files is indispensable. In particular, the use of machine-readable standard vocabularies to characterize channel metadata is essential when constructing analytic pipelines to avoid errors in processing, analysis and interpretation of results. For automation, this high-quality metadata needs to be programmatically accessible, implying the need for a consistent Application Programming Interface (API). In this manuscript, we propose that upfront time spent normalizing flow cytometry data to conform to carefully designed data models enables

  7. 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

  8. HLA-DR expression as a biomarker of inflammation for multicenter clinical trials of ocular surface disease.

    PubMed

    Epstein, Seth P; Gadaria-Rathod, Neha; Wei, Yi; Maguire, Maureen G; Asbell, Penny A

    2013-06-01

    There are currently no validated minimally invasive objective metrics for the classification and evaluation of ocular surface diseases and/or for evaluating treatment efficacy. We thus sought to establish a standardized methodology for determining the relative amount of the inflammatory biomarker HLA-DR on the ocular surface and to evaluate the precision, reliability and repeatability of its use for large multicenter clinical trials and translational research studies of ocular surface disease. Multiple studies were conducted to establish a Standard Operating Procedure (SOP) for utilizing HLA-DR expression as a minimally invasive, objective, ocular surface inflammatory biomarker. The established SOPs provide specific guidelines for HLA-DR collection and analysis, in order to incorporate it reliably into multicenter clinical trials and/or translational research. Duplicate cell samples from impression cytology (IC) samples of both normal and dry eye individuals were collected and split to assess repeatability (between the splits and between the duplicate samples). To determine storage capability, one duplicate was stained immediately and the other after 30 days cold storage. To demonstrate the feasibility of the use of the SOP for a multicenter clinical trial, clinicians out-of-state were trained to collect IC samples, and the samples shipped to our Biomarker Laboratory, logged, processed and analyzed. Demonstration of the ability to incorporate of IC into a randomized double masked clinical trial of dry eye disease (DED) was performed. In all cases, processing and analyses were performed by a masked independent observer. The validity/viability of the SOPs was established by demonstrating that: 1) sufficient numbers of cells can be collected via IC; 2) the precision/repeatability of the relative biomarker expression quantified in samples; 3) personnel at distant sites can be taught to collect, store and ship samples successfully; 4) samples can be stored for up to 30

  9. Prospective multicenter international surveillance of azole resistance in Aspergillus fumigatus.

    PubMed

    van der Linden, J W M; Arendrup, M C; Warris, A; Lagrou, K; Pelloux, H; Hauser, P M; Chryssanthou, E; Mellado, E; Kidd, S E; Tortorano, A M; Dannaoui, E; Gaustad, P; Baddley, J W; Uekötter, A; Lass-Flörl, C; Klimko, N; Moore, C B; Denning, D W; Pasqualotto, A C; Kibbler, C; Arikan-Akdagli, S; Andes, D; Meletiadis, J; Naumiuk, L; Nucci, M; Melchers, W J G; Verweij, P E

    2015-06-01

    To investigate azole resistance in clinical Aspergillus isolates, we conducted prospective multicenter international surveillance. A total of 3,788 Aspergillus isolates were screened in 22 centers from 19 countries. Azole-resistant A. fumigatus was more frequently found (3.2% prevalence) than previously acknowledged, causing resistant invasive and noninvasive aspergillosis and severely compromising clinical use of azoles. PMID:25988348

  10. Stable Atlas-based Mapped Prior (STAMP) Machine-learning Segmentation for Multicenter Large-scale MRI Data

    PubMed Central

    Kim, Eun Young; Magnotta, Vincent A.; Liu, Dawei; Johnson, Hans J.

    2014-01-01

    Machine learning (ML)-based segmentation methods are a common technique in the medical image processing field. In spite of numerous research groups that have investigated ML-based segmentation frameworks, there remains unanswered aspects of performance variability for the choice of two key components: ML-algorithm and intensity normalization. This investigation reveals that the choice of those elements plays a major part in determining segmentation accuracy and generalizability. The approach we have used in this study aims to evaluate relative benefits of the two elements within a subcortical MRI segmentation framework. Experiments were conducted to contrast eight machine-learning algorithm configurations and 11 normalization strategies for our brain MR segmentation framework. For the intensity normalization, a stable atlas-based mapped prior (STAMP) was utilized to take better account of contrast along boundaries of structures. Comparing eight machine learning algorithms on down-sampled segmentation MR data, it was obvious that a significant improvement was obtained using ensemble-based ML algorithms (i.e., random forest) or ANN algorithms. Further investigation between these two algorithms also revealed that the random forest results provided exceptionally good agreement with manual delineations by experts. Additional experiments showed that the effect of STAMP-based intensity normalization also improved the robustness of segmentation for multicenter data sets. The constructed framework obtained good multicenter reliability and was successfully applied on a large multicenter MR data set (n > 3000). Less than 10% of automated segmentations were recommended for minimal expert intervention. These results demonstrate the feasibility of using the ML-based segmentation tools for processing large amount of multicenter MR images. We demonstrated dramatically different result profiles in segmentation accuracy according to the choice of ML algorithm and intensity

  11. MiDas: automatic extraction of a common domain of discourse in sleep medicine for multi-center data integration.

    PubMed

    Sahoo, Satya S; Ogbuji, Chimezie; Luo, Lingyun; Dong, Xiao; Cui, Licong; Redline, Susan S; Zhang, Guo-Qiang

    2011-01-01

    Clinical studies often use data dictionaries with controlled sets of terms to facilitate data collection, limited interoperability and sharing at a local site. Multi-center retrospective clinical studies require that these data dictionaries, originating from individual participating centers, be harmonized in preparation for the integration of the corresponding clinical research data. Domain ontologies are often used to facilitate multi-center data integration by modeling terms from data dictionaries in a logic-based language, but interoperability among domain ontologies (using automated techniques) is an unresolved issue. Although many upper-level reference ontologies have been proposed to address this challenge, our experience in integrating multi-center sleep medicine data highlights the need for an upper level ontology that models a common set of terms at multiple-levels of abstraction, which is not covered by the existing upper-level ontologies. We introduce a methodology underpinned by a Minimal Domain of Discourse (MiDas) algorithm to automatically extract a minimal common domain of discourse (upper-domain ontology) from an existing domain ontology. Using the Multi-Modality, Multi-Resource Environment for Physiological and Clinical Research (Physio-MIMI) multi-center project in sleep medicine as a use case, we demonstrate the use of MiDas in extracting a minimal domain of discourse for sleep medicine, from Physio-MIMI's Sleep Domain Ontology (SDO). We then extend the resulting domain of discourse with terms from the data dictionary of the Sleep Heart and Health Study (SHHS) to validate MiDas. To illustrate the wider applicability of MiDas, we automatically extract the respective domains of discourse from 6 sample domain ontologies from the National Center for Biomedical Ontologies (NCBO) and the OBO Foundry. PMID:22195180

  12. MiDas: Automatic Extraction of a Common Domain of Discourse in Sleep Medicine for Multi-center Data Integration

    PubMed Central

    Sahoo, Satya S.; Ogbuji, Chimezie; Luo, Lingyun; Dong, Xiao; Cui, Licong; Redline, Susan S.; Zhang, Guo-Qiang

    2011-01-01

    Clinical studies often use data dictionaries with controlled sets of terms to facilitate data collection, limited interoperability and sharing at a local site. Multi-center retrospective clinical studies require that these data dictionaries, originating from individual participating centers, be harmonized in preparation for the integration of the corresponding clinical research data. Domain ontologies are often used to facilitate multi-center data integration by modeling terms from data dictionaries in a logic-based language, but interoperability among domain ontologies (using automated techniques) is an unresolved issue. Although many upper-level reference ontologies have been proposed to address this challenge, our experience in integrating multi-center sleep medicine data highlights the need for an upper level ontology that models a common set of terms at multiple-levels of abstraction, which is not covered by the existing upper-level ontologies. We introduce a methodology underpinned by a Minimal Domain of Discourse (MiDas) algorithm to automatically extract a minimal common domain of discourse (upper-domain ontology) from an existing domain ontology. Using the Multi-Modality, Multi-Resource Environment for Physiological and Clinical Research (Physio-MIMI) multi-center project in sleep medicine as a use case, we demonstrate the use of MiDas in extracting a minimal domain of discourse for sleep medicine, from Physio-MIMI’s Sleep Domain Ontology (SDO). We then extend the resulting domain of discourse with terms from the data dictionary of the Sleep Heart and Health Study (SHHS) to validate MiDas. To illustrate the wider applicability of MiDas, we automatically extract the respective domains of discourse from 6 sample domain ontologies from the National Center for Biomedical Ontologies (NCBO) and the OBO Foundry. PMID:22195180

  13. Oral health and risk of squamous cell carcinoma of the head and neck and esophagus: results of two multicentric case-control studies.

    PubMed

    Guha, Neela; Boffetta, Paolo; Wünsch Filho, Victor; Eluf Neto, Jose; Shangina, Oxana; Zaridze, David; Curado, Maria Paula; Koifman, Sergio; Matos, Elena; Menezes, Ana; Szeszenia-Dabrowska, Neonila; Fernandez, Leticia; Mates, Dana; Daudt, Alexander W; Lissowska, Jolanta; Dikshit, Rajesh; Brennan, Paul

    2007-11-15

    Poor oral health has been reported as a risk factor in the etiology of head and neck cancer. Data on oral health were ascertained as part of two multicenter case-control studies comprising 924 cases and 928 controls in central Europe and 2,286 cases and 1,824 controls in Latin America. Incident cases of squamous cell carcinoma of the head and neck (oral cavity, pharynx, larynx) and esophagus, as well as age (in quinquennia)- and sex frequency-matched controls, were enrolled from 1998 to 2003. Poor condition of the mouth (central Europe: odds ratio (OR) = 2.89, 95% confidence interval (CI): 1.74, 4.81; Latin America: OR = 1.89, 95% CI: 1.47, 2.42), lack of toothbrush use (Latin America: OR = 2.36, 95% CI: 1.28, 4.36), and daily mouthwash use (Latin America: OR = 3.40, 95% CI: 1.96, 5.89) emerged as risk factors for head and neck cancer, independent of tobacco use and alcohol consumption. Missing between six and 15 teeth was an independent risk factor for esophageal cancer (central Europe: OR = 2.84, 95% CI: 1.26, 6.41; Latin America: OR = 2.18, 95% CI: 1.04, 4.59). These results indicate that periodontal disease (as indicated by poor condition of the mouth and missing teeth) and daily mouthwash use may be independent causes of cancers of the head, neck, and esophagus. PMID:17761691

  14. [Risk factors of influenza (H1N1) 2009 hospitalization and effectiveness of pharmaceutical and nonpharmaceutical interventions in its prevention: a case-control study].

    PubMed

    Domínguez, Angela; Alonso, Jordi; Astray, Jenaro; Baricot, Maretva; Cantón, Rafael; Castilla, Jesús; Castro, Ady; Delgado, Miguel; Godoy, Pere; González-Candelas, Fernando; Martín, Vicente; Mayoral, José María; Quintana, José María; Perea, Emilio; Pumarola, Tomás; Soldevila, Nuria; Tamames, Sonia

    2011-01-01

    Potentially useful pharmaceutical measures to limit the impact of pandemic influenza in the community include antiviral drugs (neuraminidase inhibitors) and the influenza and pneumococcal vaccines, as influenza predisposes to bacterial pneumonia caused by Streptococcus pneumoniae. Non-pharmaceutical measures include hand washing and respiratory hygiene. Due to the lack of knowledge of the effectiveness of these measures in a pandemic situation, in September 2009, CIBER de Epidemiología y Salud Pública presented a multicenter case-control study, with controls matched for age, hospital and date of hospitalization, to investigate these aspects in 37 hospitals in 7 Spanish autonomous communities, in response to the call for research projects by the Ministry of Science and Innovation Research Program on Influenza A (H1N1) in Spain. For each confirmed hospitalized case of pandemic influenza, 1 confirmed outpatient case and 3 controls (2 hospitalized and 1 outpatient) were selected. Demographic variables, underlying medical conditions, use of antiviral agents, vaccines received and hygiene habits were collected for all cases and controls. In hospitalized cases, information on antiviral therapy and disease progression was collected. A total of 3750 patients were recruited by October 2010. Data cleansing and the recovery of variables is now underway. The involvement of the Public Health Directorate has been instrumental in adapting the project to the evolution of the pandemic. PMID:21750838

  15. 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

  16. 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. PMID:26294387

  17. Toxoplasma gondii Infection in Pregnant Women: A Seroprevalence and Case-Control Study in Eastern China

    PubMed Central

    Cong, Wei; Dong, Xiao-Yan; Meng, Qing-Feng; Zhou, Na; Wang, Xiang-Yang; Huang, Si-Yang; Zhu, Xing-Quan; Qian, Ai-Dong

    2015-01-01

    Very limited information is available concerning the epidemiology of T. gondii infection in pregnant women in eastern China. Therefore, a case-control study was conducted to estimate the seroprevalence of toxoplasmosis in this population group and to identify risk factors and possible routes of contamination. Serum samples were collected from 965 pregnant women and 965 age-matched nonpregnant control subjects in Qingdao and Weihai between October 2011 and July 2013. These were screened with enzyme linked immunoassays for the presence of anti-Toxoplasma IgG and anti-Toxoplasma IgM antibodies. 147 (15.2%) pregnant women and 167 (17.3%) control subjects were positive for anti-T. gondii IgG antibodies, while 28 (2.9%) pregnant women and 37 (3.8%) controls were positive for anti-T. gondii IgM antibodies (P = 0.256). There was no significant difference between pregnant women and nonpregnant controls with regard to the seroprevalence of either anti-T. gondii IgG or IgM antibodies. Multivariate analysis showed that T. gondii infection was associated with location, cats in home, contact with cats and dogs, and exposure to soil. The results indicated that the seroprevalence of T. gondii infection in pregnant women is high compared to most other regions of China and other East Asian countries with similar climatic conditions. PMID:26539465

  18. CD209 in inflammatory bowel disease: a case-control study in the Spanish population

    PubMed Central

    Núñez, Concepción; Oliver, Javier; Mendoza, Juan Luis; Gómez-García, María; Taxonera, Carlos; Gómez, Luis M; López-Nevot, Miguel A; de la Concha, Emilio G; Urcelay, Elena; Martínez, Alfonso; Martín, Javier

    2007-01-01

    Background The etiology of Ulcerative Colitis (UC) and Crohn's Disease (CD), considered together as Inflammatory Bowel Diseases (IBD), involves environmental and genetic factors. Although some genes are already known, the genetics underlying these diseases is complex and new candidates are continuously emerging. The CD209 gene is located in a region linked previously to IBD and a CD209 functional polymorphism (rs4804803) has been associated to other inflammatory conditions. Our aim was to study the potential involvement of this CD209 variant in IBD susceptibility. Methods We performed a case-control study with 515 CD patients, 497 UC patients and 731 healthy controls, all of them white Spaniards. Samples were typed for the CD209 single nucleotide polymorphism (SNP) rs4804803 by TaqMan technology. Frequency comparisons were performed using χ2 tests. Results No association between CD209 and UC or CD was observed initially. However, stratification of UC patients by HLA-DR3 status, a strong protective allele, showed that carriage of the CD209_G allele could increase susceptibility in the subgroup of HLA-DR3-positive individuals (p = 0.03 OR = 1.77 95% CI 1.04–3.02, vs. controls). Conclusion A functional variant in the CD209 gene, rs4804803, does not seem to be influencing Crohn's disease susceptibility. However, it could be involved in the etiology or pathology of Ulcerative Colitis in HLA-DR3-positive individuals but further studies are necessary. PMID:18070336

  19. 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

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

    PubMed

    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

  1. Oxidative stress in acute human poisoning with organophosphorus insecticides; a case control study.

    PubMed

    Ranjbar, Akram; Solhi, Hasan; Mashayekhi, Farideh Jalali; Susanabdi, Alireza; Rezaie, Ali; Abdollahi, Mohammad

    2005-07-01

    Free radicals play an important role in toxicity of pesticides and environmental chemicals. Organophosphorus insecticides (OPIs) may induce oxidative stress leading to generation of free radicals and alteration in antioxidant system. To complete the previous surveys, this study was conducted to evaluate the existence of oxidative stress, balance between total antioxidant capacity and oxygen free radicals in patients with acute OPI exposure. In this case control study, a total of 22 acute OPI poisoning patients were included and blood samples were analyzed for lipid peroxidation, total antioxidant capacity, total thiol groups, and cholinesterase levels. The results showed significant lipid peroxidation accompanied with decreased levels of total antioxidant capacity, total thiols, and cholinesterase activity. A significant correlation existed between cholinesterase depression and reduced total antioxidant capacity. It is concluded that oxygen free radicals and their related interactions like lipid peroxidation are present in acute OPI poisoning. Use of antioxidants may be beneficial in treatment of OPIs acute poisoning which remains to be elucidated by further clinical trials. PMID:21783573

  2. 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. PMID:26148934

  3. Chinese Eye Exercises and Myopia Development in School Age Children: A Nested Case-control Study.

    PubMed

    Kang, Meng-Tian; Li, Shi-Ming; Peng, Xiaoxia; Li, Lei; Ran, Anran; Meng, Bo; Sun, Yunyun; Liu, Luo-Ru; Li, He; Millodot, Michel; Wang, Ningli

    2016-01-01

    Chinese eye exercises have been implemented in China as an intervention for controlling children's myopia for over 50 years. This nested case-control study investigated Chinese eye exercises and their association with myopia development in junior middle school children. Outcome measures were the onset and progression of myopia over a two-year period. Cases were defined as 1. Myopia onset (cycloplegic spherical equivalent ≤ -0.5 diopter in non-myopic children). 2. Myopia progression (myopia shift of ≥1.0 diopter in those who were myopic at baseline). Two independent investigators assessed the quality of Chinese eye exercises performance at the end of the follow-up period. Of 260 children at baseline (mean age was 12.7 ± 0.5 years), 201 were eligible for this study. There was no association between eye exercises and the risk of myopia-onset (OR = 0.73, 95%CI: 0.24-2.21), nor myopia progression (OR = 0.79, 95%CI: 0.41-1.53). The group who performed high quality exercises had a slightly lower myopia progression of 0.15 D than the children who did not perform the exercise over a period of 2 years. However, the limited sample size, low dosage and performance quality of Chinese eye exercises in children did not result in statistical significance and require further studies. PMID:27329615

  4. 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. PMID:27429790

  5. Birth outcomes of patients with isolated anorectal malformations: A population-based case-control study.

    PubMed

    Vermes, Gabor; László, Daniel; Czeizel, Andrew E; Ács, Nándor

    2016-01-01

    In most patients affected by isolated anorectal malformation (IARM) the etiology is largely unknown. Thus, the aim of our project was to analyze possible risk factors for IARM. In the first step, birth outcomes of cases with IARM were analyzed on the basis of maternal socio-demographic variables, and these data are presented in this paper. Gestational age at delivery, birthweight, preterm birth, low birthweight and small for gestational age of cases with IARM were evaluated in the function of maternal age, birth/pregnancy order, marital and employment status of mothers in the population-based large dataset of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996. The study samples included 231 live-born cases with IARM, 361 matched and 38 151 population controls without any defect. IARMs are more frequent in males, twins and newborn infants with low birthweight and small-for-gestational-age, the latter being the consequence of intrauterine growth restriction. In addition, mothers of cases were younger but with higher birth order, and had lower socio-economic status. These maternal variables are characteristic for the gypsy population in Hungary. The higher proportion of gypsy women among the mothers of cases with IARM was confirmed during the home visits of the study. Male sex and intrauterine growth restriction of cases, in addition to low socioeconomic status and gypsy origin of mothers may have a role in the risk of IARMs. PMID:26259501

  6. Obstructive sleep apnea syndrome and non-arteritic anterior ischemic optic neuropathy: a case control study

    PubMed Central

    Ghaleh Bandi, Mir Farhad; Naserbakht, Morteza; Tabasi, Abdolreza; Marghaiezadeh, Azin; Riazee Esfahani, Mohammad; Golzarian, Zohre

    2015-01-01

    Background: Sleep apnea is temporary cessation or absence of breathing during sleep. Significant increase in blood pressure is clinically seen in apneic episodes. The aim of this study was to examine sleep apnea syndrome as a risk factor for non- arthritic anterior ischemic optic neuropathy (NAION) in a case control study. Methods: Nineteen NAION patients (9 men and 10 women) and 31 age and sex matched control participants (18 men and 13 women) were evaluated for obstructive sleep apnea syndrome (OSAS). Full night polysomnography was performed and proportion of OSAS was compared between the NAION patients and the control group. Other risk factors for NAION such as hypertension, diabetes, hyperlipidemia, ischemic heart disease and tobacco consumption were also evaluated. Chi square test and independent samples t-test were used for statistical analysis. Results: OF the 19 NAION patients, 18 (95%) had OSAS, and of the control group 13 (41.9%) had OSAS. The frequency of OSAS was significantly higher among NAION patients compared to the controls (p< 0.001). The Mean Respiratory Disturbance Index (RDI) was 37.65/h SD= 37.61/h in NAION patients and it was 15.05/h SD= 11.97/h (p= 0.018) in controls. The frequency of diabetes and hypertension was significantly higher in the NAION patients than in controls. Conclusion: based on the results of this study, it seems that there is an association between NAION and OSAS. PMID:26913263

  7. Assessing Incremental Value of Biomarkers with Multi-phase Nested case-control Studies

    PubMed Central

    Zhou, Qian M.; Zheng, Yingye; Chibnik, Lori B.; Karlson, Elizabeth W.; Cai, Tianxi

    2016-01-01

    Summary Accurate risk prediction models are needed to identify different risk groups for individualized prevention and treatment strategies. In the Nurses’ Health Study, to examine the effects of several biomarkers and genetic markers on the risk of rheumatoid arthritis (RA), a three-phase nested case-control (NCC) design was conducted, in which two sequential NCC subcohorts were formed with one nested within the other, and one set of new markers measured on each of the subcohorts. One objective of the study is to evaluate clinical values of novel biomarkers in improving upon existing risk models because of potential cost associated with assaying biomarkers. In this paper, we develop robust statistical procedures for constructing risk prediction models for RA and estimating the incremental value (IncV) of new markers based on three-phase NCC studies. Our method also takes into account possible time-varying effects of biomarkers in risk modeling, which allows us to more robustly assess the biomarker utility and address the question of whether a marker is better suited for short-term or long-term risk prediction. The proposed procedures are shown to perform well in finite samples via simulation studies. PMID:26195245

  8. 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

  9. Assessment of Vitamin K2 Levels in Osteoporotic Patients: A Case Control Study

    PubMed Central

    Noori, Akram; Lashkari, Mahin; Oveisi, Sonia; Khah, Mohamad Reza Khair; Zargar, Ali

    2014-01-01

    Objective: The aim of this study was to measure the level of Vitamin K2 (Vit K2) in osteoporotic patients and individuals with normal bone density as controls. Materials and Methods: This case-control study was done in Outpatient Department of Rheumatology at Qazvin Boo-ali Sina Hospital in 2013. Participants were 50 patients with osteoporotic densitometry measured by DEXA (T score≤ -2.5) who were matched with 48 persons in control group with normal bone density (T score> -1). The level of Vit K2 in samples was measured using enzyme linked immunosorbent assay (ELISA). Data were analyzed by Mann-Whitney U test and Chi-square test. Results: The level of Vit K2 in patients with osteoporosis was not significantly different from the control group ( Median: 75.95 vs. 71.35 nmol/L, respectively; P-value: 0.709). The authors determined cut-offs 75 percentile of vitamin K2 in all participants that was 85 nmol/L and percentages of persons in two groups were similar. Conclusion: Although Vit K2 level in patients with osteoporosis was not significantly different from the control group, further studies are necessary to confirm the association of osteoporosis and Vit K2. PMID:25363106

  10. 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. PMID:24781154

  11. Time-series microarray data simulation modeled with a case-control label.

    PubMed

    Liu, Y J; Zhang, J Y

    2016-01-01

    With advances in molecular biology, microarray data have become an important resource in the exploration of complex human diseases. Although gene chip technology continues to grow, there are still many barriers to overcome, such as high costs, small sample sizes, complex procedures, poor repeatability, and the dependence on data analysis methods. To avoid these problems, simulation data have a vital role in the study of complex diseases. A simulation method of microarray data is introduced in this study to model the occurrence and development of general diseases. Using classic statistics and control theory, five risk models are proposed. One or more models can be introduced into the baseline simulation dataset with a case-control label. In addition, time-series gene expression data can be generated to model the dynamic evolutionary process of a disease. The prevalence of each model is estimated and disease-associated genes are tested by significance analysis of microarrays. The source code, written in MATLAB, is freely and publicly available at http://sourceforge.net/projects/genesimulation/files/. PMID:27323009

  12. Using family members to augment genetic case-control studies of a life-threatening disease.

    PubMed

    Chen, Lu; Weinberg, Clarice R; Chen, Jinbo

    2016-07-20

    Survival bias is difficult to detect and adjust for in case-control genetic association studies but can invalidate findings when only surviving cases are studied and survival is associated with the genetic variants under study. Here, we propose a design where one genotypes genetically informative family members (such as offspring, parents, and spouses) of deceased cases and incorporates that surrogate genetic information into a retrospective maximum likelihood analysis. We show that inclusion of genotype data from first-degree relatives permits unbiased estimation of genotype association parameters. We derive closed-form maximum likelihood estimates for association parameters under the widely used log-additive and dominant association models. Our proposed design not only permits a valid analysis but also enhances statistical power by augmenting the sample with indirectly studied individuals. Gene variants associated with poor prognosis can also be identified under this design. We provide simulation results to assess performance of the methods. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26866629

  13. Chinese Eye Exercises and Myopia Development in School Age Children: A Nested Case-control Study

    PubMed Central

    Kang, Meng-Tian; Li, Shi-Ming; Peng, Xiaoxia; Li, Lei; Ran, Anran; Meng, Bo; Sun, Yunyun; Liu, Luo-Ru; Li, He; Millodot, Michel; Wang, Ningli

    2016-01-01

    Chinese eye exercises have been implemented in China as an intervention for controlling children’s myopia for over 50 years. This nested case-control study investigated Chinese eye exercises and their association with myopia development in junior middle school children. Outcome measures were the onset and progression of myopia over a two-year period. Cases were defined as 1. Myopia onset (cycloplegic spherical equivalent ≤ −0.5 diopter in non-myopic children). 2. Myopia progression (myopia shift of ≥1.0 diopter in those who were myopic at baseline). Two independent investigators assessed the quality of Chinese eye exercises performance at the end of the follow-up period. Of 260 children at baseline (mean age was 12.7 ± 0.5 years), 201 were eligible for this study. There was no association between eye exercises and the risk of myopia-onset (OR = 0.73, 95%CI: 0.24–2.21), nor myopia progression (OR = 0.79, 95%CI: 0.41–1.53). The group who performed high quality exercises had a slightly lower myopia progression of 0.15 D than the children who did not perform the exercise over a period of 2 years. However, the limited sample size, low dosage and performance quality of Chinese eye exercises in children did not result in statistical significance and require further studies. PMID:27329615

  14. 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.

  15. Resampling Procedures for Making Inference under Nested Case-control Studies

    PubMed Central

    Cai, Tianxi; Zheng, Yingye

    2013-01-01

    The nested case-control (NCC) design have been widely adopted as a cost-effective solution in many large cohort studies for risk assessment with expensive markers, such as the emerging biologic and genetic markers. To analyze data from NCC studies, conditional logistic regression (Goldstein and Langholz, 1992; Borgan et al., 1995) and maximum likelihood (Scheike and Juul, 2004; Zeng et al., 2006) based methods have been proposed. However, most of these methods either cannot be easily extended beyond the Cox model (Cox, 1972) or require additional modeling assumptions. More generally applicable approaches based on inverse probability weighting (IPW) have been proposed as useful alternatives (Samuelsen, 1997; Chen, 2001; Samuelsen et al., 2007). However, due to the complex correlation structure induced by repeated finite risk set sampling, interval estimation for such IPW estimators remain challenging especially when the estimation involves non-smooth objective functions or when making simultaneous inferences about functions. Standard resampling procedures such as the bootstrap cannot accommodate the correlation and thus are not directly applicable. In this paper, we propose a resampling procedure that can provide valid estimates for the distribution of a broad class of IPW estimators. Simulation results suggest that the proposed procedures perform well in settings when analytical variance estimator is infeasible to derive or gives less optimal performance. The new procedures are illustrated with data from the Framingham Offspring Study to characterize individual level cardiovascular risks over time based on the Framingham risk score, C-reactive protein (CRP) and a genetic risk score. PMID:24436503

  16. Dietary Risk Factors for Sporadic Creutzfeldt-Jakob Disease: A Confirmatory Case-Control Study

    PubMed Central

    Davanipour, Zoreh; Sobel, Eugene; Ziogas, Argyrios; Smoak, Carey; Bohr, Thomas; Doram, Keith; Liwnicz, Boleslaw

    2014-01-01

    Aims This study’s primary purpose was to determine whether earlier findings suggesting an association between sporadic Creutzfeldt-Jakob disease (sCJD), a transmissible spongiform encephalopathy of humans and specific dietary components could be replicated. The a priori hypotheses were that consumption of (i) foods likely to contain organ tissue and (ii) raw/rare meat are associated with increased sCJD risk. Study Design Population-based case-control study. Place and Duration of Study Department of Neurology, School of Medicine, Loma Linda University, Loma Linda, CA, USA; 4 years. Methodology An 11-state case-control study of pathologically confirmed, definite sCJD cases, matched controls, and a sample of control-surrogates was conducted. Ninety-six percent (106/110) of the case data was obtained in 1991-1993, prior to variant CJD publicity. Results Using control self-responses, consumption of hot dogs, sausage, pepperoni, kielbasa, “other” canned meat, poultry liver, any stomach/intestine, beef stomach/intestine, any organ tissue, and beef organ tissue was individually associated with increased sCJD risk; odds ratios (OR) ranged from 2.4 to 7.2 (0.003

  17. 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. PMID:24661884

  18. Stop Antibiotics on guidance of Procalcitonin Study (SAPS): a randomised prospective multicenter investigator-initiated trial to analyse whether daily measurements of procalcitonin versus a standard-of-care approach can safely shorten antibiotic duration in intensive care unit patients - calculated sample size: 1816 patients

    PubMed Central

    2013-01-01

    Background Unnecessary long-term use of broad-spectrum antibiotics is linked to the emergence and selection of resistant bacteria, prolonged hospitalisation and increased costs. Several clinical trials indicate that the biomarker procalcitonin (PCT) can guide antibiotic therapy. Some of these trials have shown a promising reduction in the number of antibiotic prescriptions, duration of antibiotic therapy and even length of stay in the ICU, although their size and selection criteria limit their external validity. The objectives of the Stop Antibiotics on guidance of Procalcitonin Study (SAPS) are to evaluate whether daily PCT can improve “real-life” antibiotic use in Dutch ICU’s by reduction of the duration of antibiotic treatment without an increase of recurrent infections and mortality. Methods/Design Multicenter randomised controlled intervention trial. Powered for superiority of the primary efficacy endpoint and non-inferiority on the primary safety endpoints (non-inferiority margin is set on 8%). Inclusion criteria: (1) ICU-patients aged ≥18 years and (2) receiving antibiotics for a presumed or proven infection and (3) signed informed consent. Exclusion criteria: (1) patients who require prolonged antibiotic therapy, (2) suffer from Mycobacterium tuberculosis, (3) cystic fibrosis, (4) viral or parasitic infections and (5) those that are severely immunocompromised or (6) moribund. The intervention consists solely of an advice to discontinue antibiotic treatment in case PCT has decreased by more than 80% of its peak level (relative stopping threshold) or decrease below a value of 0.5 ng/ml (absolute stopping threshold). The study hypothesis is that PCT-guided therapy is non-inferior to standard care based on implemented guidelines and local expertise, whilst reducing antibiotic usage. Computerised 1:1 randomisation will allocate 908 patients per arm. Arm 1: standard of care. Arm 2: procalcitonin-guided therapy. The primary efficacy endpoint is

  19. [Case-control studies with multinomial responses: a proposal for analysis].

    PubMed

    Mafra, Ana Carolina Cintra Nunes; Nucci, Luciana Bertoldi; Cordeiro, Ricardo; Stephan, Celso

    2010-03-01

    This study reviews articles on case-control studies in which the cases were classified in two or more types. Application of multinomial models and their adequacy for case-control studies are discussed. Among the available multinomial adjustments, we argue that the polytomous logistic model is the most suitable for obtaining epidemiological measures of risk and association in case-control studies. By way of illustration, we present an application of this model in a population-based case-control study, comparing the results with those obtained in a binomial logistic model. The multinomial approach allows investigating, in a single analysis, the occurrence of associations between covariates and more or more subclasses of cases, thus providing the epidemiologically relevant possibility of identifying individualized risk and protective factors for each subclass. PMID:20464064

  20. Case-control comparison of bacterial and protozoan microorganisms associated with gastroenteritis: application of molecular detection.

    PubMed

    Bruijnesteijn van Coppenraet, L E S; Dullaert-de Boer, M; Ruijs, G J H M; van der Reijden, W A; van der Zanden, A G M; Weel, J F L; Schuurs, T A

    2015-06-01

    The introduction of molecular detection of infectious organisms has led to increased numbers of positive findings, as observed for pathogens causing gastroenteritis (GE). However, because little is known about the prevalence of these pathogens in the healthy asymptomatic population, the clinical value of these additional findings is unclear. A case-control study was carried out in a population of patients served by general practitioners in the Netherlands. A total of 2710 fecal samples from case and matched control subjects were subjected to multiplex real-time PCR for the 11 most common bacterial and four protozoal causes of GE. Of 1515 case samples, 818 (54%) were positive for one or more target organisms. A total of 49% of the controls were positive. Higher positivity rates in cases compared to controls were observed for Campylobacter spp., Salmonella spp., Clostridium difficile, enteroinvasive Escherichia coli/Shigella spp., enterotoxigenic E. coli, enteroaggregative E. coli, atypical enteropathogenic E. coli (EPEC), Cryptosporidium parvum/hominis, and Giardia lamblia. However, Dientamoeba fragilis and Shiga-like toxigenic E. coli were detected significantly less frequent in cases than in controls, while no difference in prevalence was found for typical EPEC and enterohemorrhagic E. coli. The association between the presence of microorganisms and GE was the weakest in children aged 0 to 5 years. Higher relative loads in cases further support causality. This was seen for Campylobacter spp., Salmonella spp., enterotoxigenic E. coli, and C. parvum/hominis, and for certain age categories of those infected with C. difficile, enteroaggregative E. coli, and atypical EPEC. For D. fragilis and Shiga-like toxigenic E. coli/enterohemorrhagic E. coli, pathogen loads were lower in cases. Application of molecular diagnostics in GE is rapid, sensitive and specific, but results should be interpreted with care, using clinical and additional background information. PMID:25700890

  1. Gastrointestinal Infections and Diarrheal Disease in Ghanaian Infants and Children: An Outpatient Case-Control Study

    PubMed Central

    Krumkamp, Ralf; Sarpong, Nimako; Schwarz, Norbert Georg; Adelkofer, Julia; Loag, Wibke; Eibach, Daniel; Hagen, Ralf Matthias; Adu-Sarkodie, Yaw; Tannich, Egbert; May, Jürgen

    2015-01-01

    Introduction Diarrheal diseases are among the most frequent causes of morbidity and mortality in children worldwide, especially in resource-poor areas. This case-control study assessed the associations between gastrointestinal infections and diarrhea in children from rural Ghana. Methods Stool samples were collected from 548 children with diarrhea and from 686 without gastrointestinal symptoms visiting a hospital from 2007–2008. Samples were analyzed by microscopy and molecular methods. Results The organisms most frequently detected in symptomatic cases were Giardia lamblia, Shigella spp./ enteroinvasive Escherichia coli (EIEC), and Campylobacter jejuni. Infections with rotavirus (adjusted odds ratio [aOR] = 8.4; 95% confidence interval [CI]: 4.3–16.6), C. parvum/hominis (aOR = 2.7; 95% CI: 1.4–5.2) and norovirus (aOR = 2.0; 95%CI: 1.3–3.0) showed the strongest association with diarrhea. The highest attributable fractions (AF) for diarrhea were estimated for rotavirus (AF = 14.3%; 95% CI: 10.9–17.5%), Shigella spp./EIEC (AF = 10.5%; 95% CI: 3.5–17.1%), and norovirus (AF = 8.2%; 95% CI 3.2–12.9%). Co-infections occurred frequently and most infections presented themselves independently of other infections. However, infections with E. dispar, C. jejuni, and norovirus were observed more often in the presence of G. lamblia. Conclusions Diarrheal diseases in children from a rural area in sub-Saharan Africa are mainly due to infections with rotavirus, Shigella spp./EIEC, and norovirus. These associations are strongly age-dependent, which should be considered when diagnosing causes of diarrhea. The presented results are informative for both clinicians treating gastrointestinal infections as well as public health experts designing control programs against diarrheal diseases. PMID:25738935

  2. Is Xanthine Oxidase, a Marker in Pre-eclampsia? A Case-Control Study

    PubMed Central

    Bambrana, Vanishree; Kotur, Pushpa P

    2015-01-01

    Introduction Pre-eclampsia is an obstetrics problem that affects multiple systemic functions and leads to the increased maternal and fetal morbidity and mortality. The objective of the study was to evaluate the plasma levels of Xanthine oxidase (XO) activity, uric acid and Nitric oxide (NO) levels in women with pre-eclampsia and normal pregnancy during antenatal and postpartum period. Materials and Methods A case control study was conducted in women with normal pregnancy (n=50) and pre-eclampsia (n=50) before and after delivery. XO activity, uric acid and NO levels were determined from samples at 30-39 weeks of gestation. The current study was conducted in association with Obstetrics and Gynecology Department of R.L. Jalappa Hospital and Research Center. The blood samples were analysed for assay of XO, uric acid and NO. The results were analysed by using SPSS software version 2013. P-value < 0.05 was considered as statistically significant. Results The plasma XO activity was elevated (p<0.001) in the pre-eclampsia compared to normotensive pregnant women before delivery and decreased after delivery (p<0.001) significantly. Uric acid level showed a significant increase in pre-eclampsia when compared to the control before delivery (p<0.001) however values were non-significant after delivery. Conclusion Placenta plays a key role in the pathophysiology of pre-eclampsia. Placenta removal leads to decrease trend of xanthine oxidase activity, uric acid and elevation of Nitric oxide as reversible changes in pre-eclampsia patients within 48 hours after delivery. PMID:26557508

  3. 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. PMID:25281720

  4. HIV and Child Mental Health: A Case-Control Study in Rwanda

    PubMed Central

    Scorza, Pamela; Kanyanganzi, Frederick; Fawzi, Mary C. Smith; Sezibera, Vincent; Cyamatare, Felix; Beardslee, William; Stulac, Sara; Bizimana, Justin I.; Stevenson, Anne; Kayiteshonga, Yvonne

    2014-01-01

    BACKGROUND: The global HIV/AIDS response has advanced in addressing the health and well-being of HIV-positive children. Although attention has been paid to children orphaned by parental AIDS, children who live with HIV-positive caregivers have received less attention. This study compares mental health problems and risk and protective factors in HIV-positive, HIV-affected (due to caregiver HIV), and HIV-unaffected children in Rwanda. METHODS: A case-control design assessed mental health, risk, and protective factors among 683 children aged 10 to 17 years at different levels of HIV exposure. A stratified random sampling strategy based on electronic medical records identified all known HIV-positive children in this age range in 2 districts in Rwanda. Lists of all same-age children in villages with an HIV-positive child were then collected and split by HIV status (HIV-positive, HIV-affected, and HIV-unaffected). One child was randomly sampled from the latter 2 groups to compare with each HIV-positive child per village. RESULTS: HIV-affected and HIV-positive children demonstrated higher levels of depression, anxiety, conduct problems, and functional impairment compared with HIV-unaffected children. HIV-affected children had significantly higher odds of depression (1.68: 95% confidence interval [CI] 1.15–2.44), anxiety (1.77: 95% CI 1.14–2.75), and conduct problems (1.59: 95% CI 1.04–2.45) compared with HIV-unaffected children, and rates of these mental health conditions were similar to HIV-positive children. These results remained significant after controlling for contextual variables. CONCLUSIONS: The mental health of HIV-affected children requires policy and programmatic responses comparable to HIV-positive children. PMID:25049342

  5. Bisphenol a exposure in Mexico City and risk of prematurity: a pilot nested case control study

    PubMed Central

    2010-01-01

    Background Presence of Bisphenol A (BPA) has been documented worldwide in a variety of human biological samples. There is growing evidence that low level BPA exposure may impact placental tissue development and thyroid function in humans. The aim of this present pilot study was to determine urinary concentrations of BPA during the last trimester of pregnancy among a small subset of women in Mexico City, Mexico and relate these concentrations to risk of delivering prematurely. Methods A nested case-control subset of 60 participants in the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) study in Mexico City, Mexico were selected based on delivering less than or equal to 37 weeks of gestation and greater than 37 weeks of gestation. Third trimester archived spot urine samples were analyzed by online solid phase extraction coupled with high performance liquid chromatography isotope dilution tandem mass spectrometry. Results BPA was detected in 80.0% (N = 48) of the urine samples; total concentrations ranged from < 0.4 μg/L to 6.7 μg/L; uncorrected geometric mean was 1.52 μg/L. The adjusted odds ratio of delivering less than or equal to 37 weeks in relation to specific gravity adjusted third trimester BPA concentration was 1.91 (95%CI 0.93, 3.91, p-value = 0.08). When cases were further restricted to births occurring prior to the 37th week (n = 12), the odds ratio for specific-gravity adjusted BPA was larger and statistically significant (p < 0.05). Conclusions This is the first study to document measurable levels of BPA in the urine of a population of Mexican women. This study also provides preliminary evidence, based on a single spot urine sample collected during the third trimester, that pregnant women who delivered less than or equal to 37 weeks of gestation and prematurely (< 37 weeks) had higher urinary concentrations of BPA compared to women delivering after 37 weeks. PMID:20955576

  6. Multi-Center Traffic Management Advisor Operational Field Test Results

    NASA Technical Reports Server (NTRS)

    Farley, Todd; Landry, Steven J.; Hoang, Ty; Nickelson, Monicarol; Levin, Kerry M.; Rowe, Dennis W.

    2005-01-01

    The Multi-Center Traffic Management Advisor (McTMA) is a research prototype system which seeks to bring time-based metering into the mainstream of air traffic control (ATC) operations. Time-based metering is an efficient alternative to traditional air traffic management techniques such as distance-based spacing (miles-in-trail spacing) and managed arrival reservoirs (airborne holding). While time-based metering has demonstrated significant benefit in terms of arrival throughput and arrival delay, its use to date has been limited to arrival operations at just nine airports nationally. Wide-scale adoption of time-based metering has been hampered, in part, by the limited scalability of metering automation. In order to realize the full spectrum of efficiency benefits possible with time-based metering, a much more modular, scalable time-based metering capability is required. With its distributed metering architecture, multi-center TMA offers such a capability.

  7. A pragmatic discussion on establishing a multicenter digital imaging network.

    PubMed

    Ingeholm, Mary Lou; Levine, Betty A; Fatemi, Seyed Ali; Moser, And Hugo W

    2002-01-01

    Multicenter clinical trials for therapy evaluation of rare diseases are necessary. A digital imaging network improves the ability to share information between collaborating institutions for adrenoleukodystrophy. The DICOM 3.0 standard is used to move images over the Internet from contributing sites to the central clinical database and on to the reviewing physicians' workstations. Patient confidentiality and data integrity are ensured during transmission using virtual private network technology. Fifteen sites are participating in the network. Of these sites, 6 use the proposed protocol. The other 9 sites have either security policy issues or technical considerations that dictate alternative protocols. Network infrastructure, Internet access, image management practices, and security policies vary significantly between sites. Successful implementation of a multicenter digital imaging network requires flexibility in the implementation of network connectivity. Flexibility increases participation as well as complexity of the network. PMID:12105723

  8. Association of hip and pelvic geometrywith tibiofemoral osteoarthritis: Multicenter Osteoarthritis Study (MOST)

    PubMed Central

    Boissonneault, A; Lynch, JA; Wise, BL; Segal, NA; Gross, KD; Murray, DW; Nevitt, MC; Pandit, HG

    2014-01-01

    Objective Lateral tibiofemoral osteoarthritis (OA) is overall less common than medial tibiofemoral OA, but it is more prevalent in women. This may be explained by sex differences in hip and pelvic geometry. The aim of this study is to explore sex differences in hip and pelvic geometry and determine if such parameters are associated with the presence of compartment-specific knee OA. Methods This case-control study reports on 1,328 hips/knees from 664 participants and is an ancillary to the Multicenter Osteoarthritis Study (MOST). Of the 1,328 knees, 219 had lateral OA, 260 medial OA, and 849 no OA. Hip and pelvic measurements were taken from full-limb radiographs on the ipsilateral side of the knee of interest. After adjusting for covariates, means were compared between sexes and also between knees with medial and lateral OA versus no OA using separate regression models. Results Women were shown to have a reduced femoral offset (mean 40.9 mm vs. 45.9 mm; p=0.001) and more valgus neck-shaft angle (mean 128.4° vs. 125.9°; p<0.001) compared to men. Compared to those with no OA, knees with lateral OA were associated with a reduced femoral offset (p=0.012), increased height of hip centre (p=0.003), more valgus neck-shaft angle (p=0.042), and increased abductor angle (p=0.031). Knees with medial OA were associated with a more varus neck-shaft angle (p=0.043) and a decreased abductor angle (p=0.003). Conclusion These data suggest anatomical variations at the hip and pelvis are associated with compartment-specific knee OA and may help to explain sex differences in patterns of knee OA. PMID:24971867

  9. Multicenter study of nursing role complexity on environmental stressors and emotional exhaustion.

    PubMed

    Solomon, Deborah; Singleton, Kathleen A; Sun, Zhiyuan; Zell, Katrina; Vriezen, Kathryn; Albert, Nancy M

    2016-05-01

    Among nurses, work and cognitive complexity patterns of care were previously associated with environmental stressors, but it is unknown if complexity patterns are also associated with emotional exhaustion. A multicenter sample of hospital nurses (N=281) completed valid, reliable questionnaires. Data were analyzed using multivariable modeling. Registered nurse characteristics did not vary by work setting. Overall mean (standard deviation [SD]) standardized complexity of care score was 45.82 (13.73), reflecting moderate complexity during 3-hour work periods. Nurses experienced greater cognitive complexity patterns than work complexity patterns (p<0.001). In multivariable analyses, overall complexity of care and work and cognitive complexity patterns were not associated with high emotional exhaustion. Higher work complexity pattern score was associated with more environmental stressors (p=0.009), but there was no association between overall complexity of care or cognitive complexity pattern and environmental stressors. Interventions that reduce environmental stressors might reduce work complexity of care. PMID:27091253

  10. Association between Estrogen Receptor Alpha Gene Polymorphisms and Susceptibility to Idiopathic Scoliosis in Bulgarian Patients: A Case-Control Study

    PubMed Central

    Nikolova, Svetla; Yablanski, Vasil; Vlaev, Evgeni; Stokov, Luben; Savov, Alexey; Kremensky, Ivo

    2015-01-01

    BACKGROUND: The current consensus on idiopathic scoliosis maintains that it has a multifactorial etiology with genetic predisposing factors. AIM: Estrogen receptor alpha gene has been considered as candidate gene of idiopathic scoliosis. MATERIAL AND METHODS: We conducted a case-control study of Bulgarian population samples (eighty patients with idiopathic scoliosis and one hundred-sixty healthy unrelated gender-matched controls) trying to investigate the association between common genetic polymorphisms of estrogen receptor alpha and the susceptibility to idiopathic scoliosis. Molecular detection of the restriction polymorphisms XbaI and PvuII was performed by polymerase chain reaction following by restriction fragment length polymorphism. The statistical analysis was performed by Pearson’s chi-squared test. RESULTS: Our case-control study showed statistically significant association between the PvuII polymorphism and susceptibility to idiopathic scoliosis and curve progression. No genotype or allele of XbaI polymorphism was found to be correlated with the onset or severity of the disease. CONCLUSIONS: The identification of molecular markers with diagnostic and prognostic value could be useful for early detection of children at risk for the development of scoliosis and for prognosis of the risk for a rapid deformity progression. That would facilitate the therapy decisions and early stage treatment of the patient with the least invasive procedures. PMID:27275235

  11. A Multicenter Performance Evaluation of a Blood Glucose Monitoring System in 21 Leading Hospitals in Spain

    PubMed Central

    Bedini, José Luis; Wallace, Jane F.; Petruschke, Thorsten; Pardo, Scott

    2015-01-01

    Background: Self-monitoring of blood glucose is crucial for the effective self-management of diabetes. The present study evaluated the accuracy of the Contour® XT blood glucose monitoring system (BGMS) compared to the reference method in a large multicenter study under routine lab conditions at each hospital site. Methods: This study was conducted at 21 leading hospitals in Spain using leftover whole blood samples (n = 2100). Samples were tested with the BGMS using 1 commercial strip lot and the local laboratory hexokinase method. BGMS accuracy was assessed and results were compared to ISO 15197:2013 accuracy limit criteria and by using mean absolute relative difference analysis (MARD), consensus (Parkes) error grid (CEG), and surveillance error grid analyses (SEG). Results: Pooled analysis of 2100 measurements from all sites showed that 99.43% of the BGMS results were within the ranges accepted by the accuracy limit criteria. The overall MARD was 3.85%. MARD was 4.47% for glucose concentrations < 70 mg/dL and 3.81% for concentrations of 70-300 mg/dL. In CEG, most results (99.8%) were within zone A (“no effect on clinical action”); the remaining ones (0.2%) were in zone B (“little to no effect on clinical action”). The SEG analysis showed that most of the results (98.4%) were in the “no risk” zone, with the remaining results in the “slight, lower” risk zone. Conclusions: This is the largest multicenter study of Contour XT BGMS to date, and shows that this BGMS meets the ISO 15197:2013 accuracy limit criteria under local routine conditions in 21 leading Spanish hospitals. PMID:26253142

  12. 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 overweight (BMI ≥ 23 Kg/m2) in subclinical hypothyroidism was 2.29 (95% CI; 1.2–4.38, p = 0.011), 1.73 (95% CI; 0.82–3.62, p = 0.141), 3.04 (95% CI; 1.66–5.56, p < 0.001), 2.02 (95% CI; 1.12–3.64, p = 0.018), 3.35 (95% CI; 1.72–6.55, p < 0.001), and 0.9 (95% CI; 0.48–1.67, p = 0.753), respectively, as compared to controls. Conclusion. Subclinical hypothyroid patients are associated with higher risk for cardiovascular disease than euthyroid subjects. PMID:26523236

  13. 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.

  14. Tooth eruption sequence and dental crowding: a case-control study

    PubMed Central

    Moshkelgosha, Vahid; Khosravifard, Negar; Golkari, Ali

    2014-01-01

    When cases of dental crowding are identified and diagnosed promptly, interceptive orthodontics is particularly successful. Aim: To assess the differences in the eruption sequence of the mandibular canine and first premolar teeth in children with and without dental crowding. Materials and Methods: Children who attended the Shiraz Dental School's orthodontic clinic (Iran) from September to December 2012 were enrolled in this case-control study. Tooth size arch length discrepancy (TSALD) of all 8-10 year olds was calculated from patients’ dental models. Thirty-six children were randomly selected from those with TSALD of equal or less than 4mm (those with crowding). Each selected case was matched for sex and age with another child (as control) with TSALD>−4mm attending the same clinic, in the same time period. The existing panoramic radiographs were traced and the eruption percentages were measured for mandibular canine and first premolar teeth. The mean difference between canine and first premolar eruption percentages was compared between the case and control groups using the SPSS (version PASW 18) software and a paired sample t-test. Results: Canine and first premolar eruption percentages in the case group were 65.82±13.00 and 78.92±10.15 percent, respectively. The mean eruption percentages for canines and first premolars of the control group were 74.12±14.55 and 75.47±11.60 percent, respectively. There was a significant difference in pre-eruptive positions of canine and first premolar teeth in those with moderate to severe crowding when compared to the control group (p<0.001). Conclusion: These findings may improve the early diagnosis of children with high risk of developing moderate to severe crowding during mixed dentition. PMID:25110582

  15. Are family variables associated with ADHD, inattentive type? A case-control study in schools.

    PubMed

    Pheula, Gabriel Ferreira; Rohde, Luis Augusto; Schmitz, Marcelo

    2011-03-01

    Attention-deficit/hyperactivity disorder (ADHD) seems to be associated with significant psychosocial adversity. However, few studies assessed the role of environmental, social and interpersonal factors specifically in ADHD, inattentive type (ADHD-I). Thus, this study aims to investigate whether family environment risk factors are associated with ADHD-I. In a case-control study, we assessed a non-referred sample of 100 children and adolescents with ADHD-I and 100 non-ADHD controls (6-18 years old). They were systematically evaluated through structured diagnostic interviews. The following family adversity measures were used: Rutter's family adversity index (marital discord, low social class, large family size, paternal criminality, maternal mental disorder), Family Environment Scale (FES) (subscores of cohesion, expressiveness and conflict) and Family Relationship Index (FRI) (based on the subscores above). After adjusting for confounding factors (social phobia and maternal history of ADHD), the odds ratio (OR) for ADHD-I increased as the number of Rutter's indicators increased. Families of children with lower FES cohesion subscores presented higher OR for ADHD-I (OR 1.24; 95% confidence interval 1.05-1.45). Lower levels of FRI, a general index of family relationship, were also related to higher risk of ADHD-I (OR 1.11; 95% confidence interval 1.03-1.21). Our findings suggest that family adversity (in general), low family cohesion and low FRI (in particular) are associated with an increase in the risk for ADHD-I. However, the cross-sectional nature of the study limits our ability to infer causality. PMID:21290154

  16. Serum Homocysteine and Total Antioxidant Status in Vitiligo: A Case Control Study in Indian Population

    PubMed Central

    Gupta, Shikha; D'souza, Paschal; Dhali, Tapan Kumar; Arora, Sarika

    2016-01-01

    Background: Oxidative stress is considered as an initial pathogenic event in melanocyte destruction. These free radicals are scavenged by antioxidants, whose sum of activity in serum is measured by total antioxidant status (TAS). In addition, homocysteine (Hcy) may mediate melanocyte destruction via increased oxidative damage. However, previous studies investigating these parameters in vitiligo provide equivocal results. Aims: To study and compare serum Hcy and TAS levels in vitiligo patients with controls and also to correlate these parameters with the various disease characteristics. The present study further looked into any correlation between serum Hcy and TAS in vitiligo. Materials and Methods: A case control study was conducted on 82 vitiligo patients and 83 controls aged 18–45 years after excluding factors which could potentially alter serum Hcy or TAS levels. Disease characteristics were studied and blood samples were obtained for measuring serum Hcy and TAS levels. Results: TAS levels were lower in vitiligo patients than controls (1.79 ± 0.51 vs. 2.16 ± 0.63 mmol/L; P < 0.001) and had a negative correlation with disease activity (r = −0.410, P < 0.001). However, serum Hcy levels were comparable between vitiligo patients (18.68 ± 9.90 μmol/L) and controls (20.21 ± 13.39 μmol/L) (P = 0.406). No significant correlation was found between serum Hcy and serum TAS levels. Conclusions: Serum TAS may be further investigated to establish its role as biomarker for vitiligo since its levels also correlate with disease activity. However, serum Hcy may not be a reliable marker in Indian population probably because of differences in dietary habits. PMID:27057010

  17. Self-Efficacy After Life Skills Training: A Case-Control Study

    PubMed Central

    Rezayat, Fatemeh; Dehghan Nayeri, Nahid

    2013-01-01

    Background: Nursing students’ self-efficacy is a predictor for their educational progress. Students, who believe that they can be successful in their studies, are more confident. Therefore, many universities have focused on life skills training programs to improve the mental health of their students. Objectives: This study was conducted to evaluate and compare self-efficacy in two groups of nursing students of Tehran University of Medical Sciences (TUMS). One group of students was trained on life skill programs, and the second group was not trained on the issue. Materials and Methods: A case-control study was conducted on two groups of nursing students in TUMS in the late 2012. The case group (n = 112) had passed life skills training course, and the control group (n = 139) was not trained on the issue. Data was collected using a questionnaire containing 12 questions about demographic features, and the Sherer’s general self-efficacy questionnaire. Data analysis was performed using independent sample t-test, Chi-square, odds ratio, and Fisher’s exact test. Results: In the untrained and trained groups, 23% and 8% of the students had very high self-efficacy, respectively. The overall mean scores of self-efficacy were 41.99 ± 9.31 and 38.99 ± 10.48 in the trained and untrained groups, respectively (P = 0.015), and the higher mean score indicates lower level of self-efficacy. A significant difference was also found between the self-efficacy and family income (P = 0.029). Conclusions: The present study showed that life skills training program did not affect self-efficacy of nursing students. Perhaps, the methods used in education were influencing and then, more effective techniques such as role-play and group discussion should be substituted in life skills training. PMID:25414884

  18. A case-control study of the congenital hypothyroidism and dysmaturity syndrome of foals.

    PubMed Central

    Allen, A L; Townsend, H G; Doige, C E; Fretz, P B

    1996-01-01

    A case-control study was conducted to identify risk factors for the congenital hypothyroidism and dysmaturity syndrome of foals. A questionnaire was used during personal interviews of foal owners and farm managers to collect information on animal signalment, farm environment, and mare management. Information on 39 foals with the congenital hypothyroidism and dysmaturity syndrome were compared with 39 control foals. Foals with the syndrome had a significantly (P < 0.0001) longer gestation (357.6 d) than control foals (338.9 d). Pregnant mares that were fed greenfeed, did not receive any supplemental mineral, left their "home farm" during gestation, or grazed irrigated pasture had 13.1 (P = 0.0068), 5.6 (P = 0.0472), 4.3 (P = 0.0076), and approximately 15.3 (P = 0.0245), respectively, greater odds of producing an affected foal than mares not experiencing these events. Greenfeed often contains high levels of nitrate (NO3-), which is known to impair thyroid gland function. In light of this, forage samples from participating farms were analyzed for nitrate levels. The odds of one or more congenitally hypothyroid and dysmature foals being born on a farm feeding forage with at least a trace of nitrate was 8.0 times greater (P = 0.0873) than the odds of the disease occurring on a farm that fed forage free of nitrate. Further, the odds of a mare producing an affected foal when fed forage containing at least a trace of nitrate were 5.9 times greater (P = 0.0007) than those of a mare fed nitrate free forage. This study suggests that congenital hypothyroidism and dysmaturity syndrome in foals may be the result of diets that contain nitrate or that are low in iodine being fed to pregnant mares. PMID:8689594

  19. Case-control study of risk factors for disease in the neck and shoulder area.

    PubMed

    Ekberg, K; Björkqvist, B; Malm, P; Bjerre-Kiely, B; Karlsson, M; Axelson, O

    1994-04-01

    A case-control study was performed to elucidate the strength of the relation between musculoskeletal disorders in the neck and shoulders and physical, organisational, and psychosocial aspects of the work environment. Cases were identified as those persons who consulted a physician in a community in southern Sweden for new musculoskeletal disorders in the neck and shoulders during a study period from August 1988 to the end of October 1989. One hundred and nine cases were collected and clinically examined. The cases also answered the Nordic questionnaire on symptoms as well as a questionnaire on work conditions and background factors. Controls were drawn as a random sample of the working population in the community where the cases appeared. A total of 637 controls answered the same questionnaires as the cases. Odds ratios (ORs) were calculated by logistic regression. The odds ratios were 11.4 for women, 4.9 for immigrant background, and 3.7 for current smoking. To exercise rarely, compared with often, appeared as a preventive factor with an OR of 0.3. The ORs for various determinants of physical work load were 7.5 for repetitive movements demanding precision, 13.6 for light lifting, 3.6 for uncomfortable sitting positions, 4.8 for work with lifted arms, and 3.5 for a rushed work pace. Regarding work organisational determinants, the ORs were 16.5 for ambiguity of work role (uncertainty whether the person could manage the work) 2.6 for low quality work, and 3.8 for high demands on attention. Several of the determinants showed a significant dose-response relation with disease. It seems that work organisation and psychosocial work conditions are as important determinants for disease in the neck and shoulders as are the physical work conditions. PMID:8199669

  20. Both Acute and Chronic Placental Inflammation Are Overrepresented in Term Stillbirths: A Case-Control Study

    PubMed Central

    Hulthén Varli, Ingela; Petersson, Karin; Kublickas, Marius; Papadogiannakis, Nikos

    2012-01-01

    Objective. To elucidate differences in the frequency and severity of acute chorioamnionitis (CAM) and chronic villitis in placentas from stillborns compared with liveborns at term and to evaluate other risk factors and placental findings. Design. Case-control study. Setting. All delivery wards in major Stockholm area. Population or Sample. Placentas from stillborn/case (n = 126) and liveborn/control (n = 273) neonates were prospectively collected between 2002 and 2005. Methods. CAM was assessed on a three-grade scale based on the presence and distribution of polymorphonuclear leucocytes in the chorion/amnion. The presence of vasculitis and funisitis was recorded separately. Chronic villitis was diagnosed by the presence of mononuclear cells in the villous stroma. Relevant clinical data were collected from a specially constructed, web-based database. The statistic analyses were performed using multivariable logistic regression. Results. CAM (especially severe, AOR: 7.39 CI: 3.05–17.95), villous immaturity (AOR: 7.17 CI: 2.66–19.33), villitis (<1 % AOR: 4.31 CI: 1.16–15.98; ≥1 %, AOR: 3.87 CI: 1.38–10.83), SGA (AOR: 7.52 CI: 3.06–18.48), and BMI >24.9 (AOR: 2.06 CI: 1.21–3.51) were all connected to an elevated risk of term stillbirth. Conclusions. We found that CAM, chronic villitis, villous immaturity, SGA, and maternal overweight, but not vasculitis or funisitis are independently associated with risk for stillbirth at term. PMID:22966214

  1. 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

  2. Case-control study of the PERIOD3 clock gene length polymorphism and colorectal adenoma formation.

    PubMed

    Alexander, Melannie; Burch, James B; Steck, Susan E; Chen, Chin-Fu; Hurley, Thomas G; Cavicchia, Philip; Ray, Meredith; Shivappa, Nitin; Guess, Jaclyn; Zhang, Hongmei; Youngstedt, Shawn D; Creek, Kim E; Lloyd, Stephen; Yang, Xiaoming; Hébert, James R

    2015-02-01

    Clock genes are expressed in a self-perpetuating, circadian pattern in virtually every tissue including the human gastrointestinal tract. They coordinate cellular processes critical for tumor development, including cell proliferation, DNA damage response and apoptosis. Circadian rhythm disturbances have been associated with an increased risk for colon cancer and other cancers. This mechanism has not been elucidated, yet may involve dysregulation of the 'period' (PER) clock genes, which have tumor suppressor properties. A variable number tandem repeat (VNTR) in the PERIOD3 (PER3) gene has been associated with sleep disorders, differences in diurnal hormone secretion, and increased premenopausal breast cancer risk. Susceptibility related to PER3 has not been examined in conjunction with adenomatous polyps. This exploratory case-control study was the first to test the hypothesis that the 5-repeat PER3 VNTR sequence is associated with increased odds of adenoma formation. Information on demographics, medical history, occupation and lifestyle was collected prior to colonoscopy. Cases (n=49) were individuals with at least one histopathologically confirmed adenoma. Controls (n=97) included patients with normal findings or hyperplastic polyps not requiring enhanced surveillance. Unconditional multiple logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs), after adjusting for potential confounding. Adenomas were detected in 34% of participants. Cases were more likely to possess the 5-repeat PER3 genotype relative to controls (4/5 OR, 2.1; 95% CI, 0.9-4.8; 5/5 OR, 5.1; 95% CI, 1.4-18.1; 4/5+5/5 OR, 2.5; 95% CI, 1.7-5.4). Examination of the Oncomine microarray database indicated lower PERIOD gene expression in adenomas relative to adjacent normal tissue. Results suggest a need for follow-up in a larger sample. PMID:25501848

  3. 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

  4. 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

  5. Eating and weight related cognitions in people with Schizophrenia : A case control study

    PubMed Central

    2006-01-01

    Background Patients with antipsychotic-induced weight gain (WG) regularly report on unsuccessful dietary trials, which suggests strong biological weight gain drive that is extremely hard to overcome with thoughts, such that behaviour doesn't change despite some intent to change. The purpose of the present study was to assess cognitions specifically related to restrained eating in severely overweight patients with schizophrenia treated with antipsychotic drugs. Methods Forty outpatients with schizophrenia and 40 controls without psychiatric disability were included. Both groups were composed of one subgroup severely overweight (defined as a BMI > 28), and a comparison sample (BMI<28). The revised version of the Mizes Anorectic cognitive questionnaire (MAC-R) was used in this cross-sectional case-control study. Results Gender was significantly related to eating disorders cognition, women scoring higher than men. Patients with schizophrenia in general scored higher on the MAC-R total scale and on the MAC-R subscale 2, the latter score representing rigid weight regulation and fear of weight gain. When comparing the two groups of subjects with BMI < 28, it appeared that patients with schizophrenia also scored higher on MAC-R total scale, the subscales 2 and 3, the latter subscale 3, indicating altered self control and self-esteem. Conclusion As is the case in weight gain of subjects without schizophrenia, the present results suggest that the cognitive distortions, as assessed by the MAC-R, may play an important role in weight gain also in patients with schizophrenia, and in weight gain associated with antipsychotic pharmacotherapy. Particular attention to these processes may help to improve the management of antipsychotic drugs induced weight gain. PMID:17076886

  6. Dairy Consumption and Risk of Stroke: A Case-control Study

    PubMed Central

    Boroujeni, Hossein Khosravi; Saadatnia, Mohammad; Shakeri, Forough; Keshteli, Ammar Hassanzadeh; Saneei, Parvane; Esmaillzadeh, Ahmad

    2016-01-01

    Background: It remains controversial if dairy product intake is associated with risk of stroke. Limited information is available from Middle East countries in this regard. This case-control study was conducted to assess the relationship between dairy consumption and risk of stroke in Iranian adults. Methods: In this study, 195 stroke patients (recognized based on clinical findings and computed tomography scan) hospitalized in neurology ward of Alzahra University Hospital were enrolled. Controls (n = 195) were selected with convenience nonrandom sampling procedure from other wards of this hospital. A validated food frequency questionnaire was used to assess participants’ usual dietary intakes. Data on other variables were collected by the use of questionnaires. Results: Patients with stroke were older (P < 0.001), had lower weight and body mass index (P < 0.05) and were more likely to be male (P < 0.05) and less likely to be obese (P < 0.001). After adjustment for age, sex and total energy intake, Individuals with the highest consumption of low-fat dairy had a significantly decreased risk of stroke (odds ratio [OR]: 0.58; 95% of confidence interval [CI]: 0.34–0.99), while those with the highest intake of high-fat dairy had a 2-fold increased risk of stroke. The association between high-fat dairy consumption and stroke even persisted after additional adjustments for physical activity, smoking and dietary variables (OR: 2.02; 95% CI: 1.02–4.02); but the association between low-fat dairy intake and stroke disappeared after these adjustments (OR: 0.84; 95% CI: 0.44–1.58). Conclusions: We found a significant positive association between high-fat dairy consumption and risk of stroke. Further prospective studies are required to confirm this finding. PMID:26941903

  7. Air Pollution and the Risk of Cardiac Defects: A Population-Based Case-Control Study.

    PubMed

    Hwang, Bing-Fang; Lee, Yungling Leo; Jaakkola, Jouni J K

    2015-11-01

    Previous epidemiologic studies have assessed the role of the exposure to ambient air pollution in the development of cardiac birth defects, but they have provided somewhat inconsistent results. To assess the associations between exposure to ambient air pollutants and the risk of cardiac defects, a population-based case-control study was conducted using 1087 cases of cardiac defects and a random sample of 10,870 controls from 1,533,748 Taiwanese newborns in 2001 to 2007.Logistic regression was performed to calculate odds ratios for 10 ppb increases in O3 and 10 μg/m increases in PM10. In addition, we compared the risk of cardiac defects in 4 categories-high exposure (>75th percentile); medium exposure (75th to 50th percentile); low exposure (<50th-25th percentile); reference (<25th percentile) based on the distribution of each pollutant. The risks of ventricular septal defects (VSD), atrial septal defects (ASD), and patent ductus arteriosus (PDA) were associated with 10 ppb increases in O3 exposure during the first 3 gestational months among term and preterm babies. In comparison between high PM10 exposure and reference category, there were statistically significant elevations in the effect estimates of ASD for all and terms births. In addition, there was a negative or weak association between SO2, NO2, CO, and cardiac defects.The study proved that exposure to outdoor air O3 and PM10 during the first trimester of gestation may increase the risk of VSD, ASD, and PDA. PMID:26554783

  8. TREM2 R47H variant and risk of essential tremor: A cross-sectional international multicenter study

    PubMed Central

    Ortega-Cubero, Sara; Lorenzo-Betancor, Oswaldo; Lorenzo, Elena; Agúndez, José A.G.; Jiménez-Jiménez, Félix J.; Ross, Owen A.; Wurster, Isabel; Mielke, Carina; Lin, Juei-Jueng; Coria, Francisco; Clarimon, Jordi; Ezquerra, Mario; Brighina, Laura; Annesi, Grazia; Alonso-Navarro, Hortensia; García-Martin, Elena; Gironell, Alex; Marti, Maria J.; Yueh, Kuo-Chu; Wszolek, Zbigniew K.; Sharma, Manu; Berg, Daniela; Krüger, Rejko; Pastor, Maria A.; Pastor, Pau

    2015-01-01

    Introduction Essential tremor (ET) is the most frequent movement disorder in adults. Its pathophysiology is not clearly understood, however there is growing evidence showing common etiologic factors with other neurodegenerative disorders such as Alzheimer’s and Parkinson’s diseases (AD, PD). Recently, a rare p.R47H substitution (rs75932628) in the TREM2 protein (triggering receptor expressed on myeloid cells 2; OMIM: *605086) has been proposed as a risk factor for AD, PD and amyotrophic lateral sclerosis (ALS). The objective of the study was to determine whether TREM2 p.R47H allele is also a risk factor for developing ET. Methods This was a cross-sectional multicenter international study. An initial case-control cohort from Spain (n = 456 ET, n = 2715 controls) was genotyped. In a replication phase, a case-control series (n = 897 ET, n = 1449 controls) from different populations (Italy, Germany, North-America and Taiwan) was studied. Owed to the rarity of the variant, published results on p.R47H allele frequency from 14777 healthy controls from European, North American or Chinese descent were additionally considered. The main outcome measure was p.R47H (rs75932628) allelic frequency. Results There was a significant association between TREM2 p.R47H variant and ET in the Spanish cohort (odds ratio [OR], 5.97; 95% CI, 1.203–29.626; p = 0.042), but it was not replicated in other populations. Conclusions These results argue in favor of population-specific differences in the allelic distribution and suggest that p.R47H (rs75932628) variant may contribute to the susceptibility of ET in Spanish population. However, taking into account the very low frequency of p.R47H, further confirmatory analyses of larger ET series are needed. PMID:25585992

  9. Epstein-Barr Virus and Gastric Cancer Risk: A Meta-analysis With Meta-regression of Case-control Studies

    PubMed Central

    2016-01-01

    Objectives: Research on how the risk of gastric cancer increases with Epstein-Barr virus (EBV) infection is lacking. In a systematic review that investigated studies published until September 2014, the authors did not calculate the summary odds ratio (SOR) due to heterogeneity across studies. Therefore, we include here additional studies published until October 2015 and conduct a meta-analysis with meta-regression that controls for the heterogeneity among studies. Methods: Using the studies selected in the previously published systematic review, we formulated lists of references, cited articles, and related articles provided by PubMed. From the lists, only case-control studies that detected EBV in tissue samples were selected. In order to control for the heterogeneity among studies, subgroup analysis and meta-regression were performed. Results: In the 33 case-control results with adjacent non-cancer tissue, the total number of test samples in the case and control groups was 5280 and 4962, respectively. In the 14 case-control results with normal tissue, the total number of test samples in case and control groups was 1393 and 945, respectively. Upon meta-regression, the type of control tissue was found to be a statistically significant variable with regard to heterogeneity. When the control tissue was normal tissue of healthy individuals, the SOR was 3.41 (95% CI, 1.78 to 6.51; I-squared, 65.5%). Conclusions: The results of the present study support the argument that EBV infection increases the risk of gastric cancer. In the future, age-matched and sex-matched case-control studies should be conducted. PMID:27055546

  10. 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

  11. No association between ZNF804A rs1344706 and schizophrenia in a case-control study of Han Chinese.

    PubMed

    Wang, Jun; Zhao, Shuidi; Shugart, Yin Yao; Zhou, Zhenhe; Jin, Chunhui; Yuan, Jianmin; Wang, Guoqiang; Wang, Dong; Cheng, Zaohuo; Zhang, Fuquan

    2016-04-01

    Previous studies indicated that the single nucleotide polymorphism (SNP) rs1344706 within the gene ZNF804A was a promising risk variant for schizophrenia in European populations. However, existing results are inconsistent in Han Chinese. Hoping to validate the association of rs1344706 with schizophrenia susceptibility in Han Chinese, we conducted a case-control study in 1284 cases and 990 healthy controls from Jiangsu Province, China. We did not detect any significant between-group difference (all P>0.05) in either allele or genotype frequency under any genetic model between cases and controls. Stratified analysis by sex also failed to find any significant association. Our results did not support the association of rs1344706 with schizophrenia in Han Chinese, and further association studies with large samples from other ethnic backgrounds and focus on more SNPs of ZNF804A are warranted. PMID:26934312

  12. Process Evaluation in the Multicenter Child and Adolescent Trial for Cardiovascular Health (CATCH).

    ERIC Educational Resources Information Center

    McGraw, Sarah A.; And Others

    1994-01-01

    Includes "Design of Process Evaluation (PE) within the Child and Adolescent Trial for Cardiovascular Health,""Classroom PE in a Multicenter Trial,""Food Service Program PE,""Physical Activity PE,""Family PE,""PE of Environmental Factors and Programs,""Challenges of Conducting PE in a Multicenter Trial." (SK)

  13. Neutrophil Gelatinase Associated Lipocalin (NGAL) in Leptospirosis Acute Kidney Injury: A Multicenter Study in Thailand

    PubMed Central

    Srisawat, Nattachai; Praditpornsilpa, Kearkiat; Patarakul, Kanitha; Techapornrung, Malee; Daraswang, Tinnapop; Sukmark, Theerapon; Khositrangsikun, Kamol; Fakthongyoo, Apinya; Oranrigsupak, Petchdee; Praderm, Laksamon; Suwattanasilpa, Ummarit; Peerapornratana, Sadudee; Loahaveeravat, Passisd; Suwachittanont, Nattachai; Wirotwan, Thaksa-on; Phonork, Chayanat; Kumpunya, Sarinya; Tiranathanagul, Khajohn; Chirathaworn, Chintana; Eiam-ong, Somchai; Tungsanga, Kriang; Sitprija, Visith; Kellum, John A.; Townamchai, Natavudh

    2015-01-01

    AKI is one of the most serious complications of leptospirosis, an important zoonosis in the tropics. Recently, NGAL, one of the novel AKI biomarkers, is extensively studied in various specific settings such as sepsis, cardiac surgery, and radiocontrast nephropathy. In this multicenter study, we aimed to study the role of NGAL as an early marker and an outcome predictor of leptospirosis associated AKI. Patients who presented with clinical suspiciousness of leptospirosis were prospectively enrolled in 9 centers from August 2012 to November 2014. The first day of enrollment was the first day of clinical suspicious leptospirosis. Blood and urine samples were serially collected on the first three days and day 7 after enrollment. We used three standard techniques (microscopic agglutination test, direct culture, and PCR technique) to confirm the diagnosis of leptospirosis. KDIGO criteria were used for AKI diagnosis. Recovery was defined as alive and not requiring dialysis during hospitalization or maintaining maximum KDIGO stage at hospital discharge. Of the 221 recruited cases, 113 cases were leptospirosis confirmed cases. Thirty seven percent developed AKI. Median uNGAL and pNGAL levels in those developing AKI were significantly higher than in patients not developing AKI [253.8 (631.4) vs 24.1 (49.6) ng/ml, p < 0.001] and [1,030 (802.5) vs 192.0 (209.0) ng/ml, p < 0.001], respectively. uNGAL and pNGAL levels associated with AKI had AUC-ROC of 0.91, and 0.92, respectively. Both of urine NGAL and pNGAL level between AKI-recovery group and AKI-non recovery were comparable. From this multicenter study, uNGAL and pNGAL provided the promising result to be a marker for leptospirosis associated AKI. However, both of them did not show the potential role to be the predictor of renal recovery in this specific setting. PMID:26629810

  14. DRINKING WATER SOURCE AND RISK OF BLADDER CANCER: A CASE-CONTROL STUDY

    EPA Science Inventory

    A water source component was included in a large population based case-control interview study of artificial sweetners. Relative risk from using chlorinated surface water sources is not elevated in the exposed groups, and there is no suggestion of a duration-response relationship...

  15. Ear Playing and Aural Development in the Instrumental Lesson: Results from a "Case-Control" Experiment

    ERIC Educational Resources Information Center

    Baker, David; Green, Lucy

    2013-01-01

    This article reports on a case-control experiment that was conducted in 2012 as part of the Ear Playing Project (EPP) at the Institute of Education, University of London. The EPP developed from the "informal learning" strand of Musical Futures and engaged instrumental students in the UK in learning from specially-created audio recordings…

  16. 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...

  17. 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…

  18. CASE-CONTROL STUDY OF ASBESTOS IN DRINKING WATER AND CANCER RISK

    EPA Science Inventory

    The authors conducted a case-control, interview-based study of the risk of developing cancer from asbestos in drinking water. The Everett, Washington, area was selected for the study because of the unusually high concentration of chrysotile asbestos in the drinking water it draws...

  19. 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...

  20. ANALYSIS OF CASE-CONTROL DATA WITH COVARIATE MEASUREMENT ERROR: APPLICATION TO DIET AND COLON CANCER

    EPA Science Inventory

    We propose a method for estimating odds ratios from case-control data in which ovariates are subject to mesurement error. he mesurement error may contain both a random component and a systematic difference between cases and controls (recall bias). ultivariate normal discriminant ...

  1. Caffeine consumption and benign breast disease: a case-control comparison.

    PubMed

    Marshall, J; Graham, S; Swanson, M

    1982-06-01

    In this case-control comparison of 323 women with benign breast disease and 1,458 controls, no differences were noted in the coffee and tea consumption patterns of the cases and controls. These findings do not support the recent suggestion of Minton, et al, that methylxanthine ingestion is causally related to benign breast disease or breast cancer. PMID:7072882

  2. 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…

  3. CASE-CONTROL CANCER MORTALITY STUDY AND CHLORINATION OF DRINKING WATER IN LOUISIANA

    EPA Science Inventory

    Several Louisiana parished (counties) using the Mississippi River for their source of public drinking water have the highest mortality rates (1950-69) in the United States for several cancers. Therefore, a case-control mortality study on cancer of the liver, brain, pancreas, blad...

  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. 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…

  6. Urinary Proteins, Vitamin D and Genetic Polymorphisms as Risk Factors for Febrile Urinary Tract Infection and Relation with Bacteremia: A Case Control Study

    PubMed Central

    van der Starre, Willize E.; van Nieuwkoop, Cees; Thomson, Uginia; Zijderveld-Voshart, Marleen S. M.; Koopman, Jan Pieter R.; van der Reijden, Tanny J. K.; van Dissel, Jaap T.; van de Vosse, Esther

    2015-01-01

    Objective/Purpose Febrile urinary tract infection (UTI) is a common bacterial disease that may lead to substantial morbidity and mortality especially among the elderly. Little is known about biomarkers that predict a complicated course. Our aim was to determine the role of certain urinary cytokines or antimicrobial proteins, plasma vitamin D level, and genetic variation in host defense of febrile UTI and its relation with bacteremia. Methods A case-control study. Out of a cohort of consecutive adults with febrile UTI (n = 787) included in a multi-center observational cohort study, 46 cases with bacteremic E.coli UTI and 45 cases with non-bacteremic E.coli UTI were randomly selected and compared to 46 controls. Urinary IL-6, IL-8, LL37, β-defensin 2 and uromodulin as well as plasma 25-hydroxyvitamin D were measured. In 440 controls and 707 UTI patients polymorphisms were genotyped in the genes CXCR1, DEFA4, DEFB1, IL6, IL8, MYD88, UMOD, TIRAP, TLR1, TLR2, TLR5 and TNF. Results IL-6, IL-8, and LL37 are different between controls and UTI patients, although these proteins do not distinguish between patients with and without bacteremia. While uromodulin did not differ between groups, inability to produce uromodulin is more common in patients with bacteremia. Most participants in the study, including the controls, had insufficient vitamin D and, at least in winter, UTI patients have lower vitamin D than controls. Associations were found between the CC genotype of IL6 SNP rs1800795 and occurrence of bacteremia and between TLR5 SNP rs5744168 and protection from UTI. The rare GG genotype of IL6 SNP rs1800795 was associated with higher β-defensin 2 production. Conclusion Although no biomarker was able to distinguish between UTI with or without bacteremia, two risk factors for bacteremia were identified. These were inability to produce uromodulin and an IL6 rs1800795 genotype. PMID:25807366

  7. Lack of association of dairy food, calcium, and vitamin D intake with the risk of Parkinson's disease: a case-control study in Japan.

    PubMed

    Miyake, Y; Tanaka, K; Fukushima, W; Sasaki, S; Kiyohara, C; Tsuboi, Y; Yamada, T; Oeda, T; Miki, T; Kawamura, N; Sakae, N; Fukuyama, H; Hirota, Y; Nagai, M

    2011-02-01

    Three previous cohort studies in the USA reported that dairy product consumption was significantly associated with an increased risk of Parkinson's disease (PD) in men, but not in women. We examined the relationship between consumption of dairy products, calcium, and vitamin D and the risk of PD using data from a multicenter hospital-based case-control study in Japan. Included were 249 cases within 6 years of onset of PD based on the UK PD Society Brain Bank clinical diagnostic criteria. Controls were 368 inpatients and outpatients without a neurodegenerative disease. Information on dietary factors was collected using a validated self-administered diet history questionnaire. Adjustment was made for sex, age, region of residence, pack-years of smoking, years of education, body mass index, and dietary factors including cholesterol, dietary glycemic index, vitamin E, β-carotene, vitamin B(6), caffeine, iron, and alcohol. Total dairy product consumption was not materially associated with the risk of PD (P for trend = 0.62). No evident relationships were observed between intake of milk, yogurt, cheese, or ice cream and the risk of PD (P for trend = 0.75, 0.63, 0.59, and 0.35, respectively). There were no measurable associations between consumption of calcium or vitamin D and PD (P for trend = 0.37 and 0.69, respectively). No significant interactions were observed between the dietary exposures and sex regarding PD. Our results suggest that intake of dairy products, calcium, and vitamin D was not related to PD, regardless of sex. However, such null relationships might be a consequence of PD. PMID:21169048

  8. Reliability of 3-Dimensional Measures of Single-Leg Drop Landing Across 3 Institutions: Implications for Multicenter Research for Secondary ACL-Injury Prevention

    PubMed Central

    Myer, Gregory D.; Bates, Nathaniel A.; DiCesare, Christopher A.; Barber Foss, Kim D.; Thomas, Staci M.; Wordeman, Samuel C.; Sugimoto, Dai; Roewer, Benjamin D.; Medina McKeon, Jennifer M.; Di Stasi, Stephanie L.; Noehren, Brian W.; McNally, Michael; Ford, Kevin R.; Kiefer, Adam W.; Hewett, Timothy E.

    2016-01-01

    Context Due to the limitations of single-center studies in achieving appropriate sampling with relatively rare disorders, multicenter collaborations have been proposed to achieve desired sampling levels. However, documented reliability of biomechanical data is necessary for multicenter injury-prevention studies and is currently unavailable. Objective To measure the reliability of 3-dimensional (3D) biomechanical waveforms from kinetic and kinematic variables during a single-leg landing (SLL) performed at 3 separate testing facilities. Design Multicenter reliability study. Setting 3 laboratories. Patients 25 female junior varsity and varsity high school volleyball players who visited each facility over a 1-mo period. Intervention Subjects were instrumented with 43 reflective markers to record 3D motion as they performed SLLs. During the SLL the athlete balanced on 1 leg, dropped down off of a 31-cm-high box, and landed on the same leg. Kinematic and kinetic data from both legs were processed from 2 trials across the 3 laboratories. Main Outcome Measures Coefficients of multiple correlations (CMC) were used to statistically compare each joint angle and moment waveform for the first 500 ms of landing. Results Average CMC for lower-extremity sagittal-plane motion was excellent between laboratories (hip .98, knee .95, ankle .99). Average CMC for lower-extremity frontal-plane motion was also excellent between laboratories (hip .98, knee .80, ankle .93). Kinetic waveforms were repeatable in each plane of rotation (3-center mean CMC ≥.71), while knee sagittal-plane moments were the most consistent measure across sites (3-center mean CMC ≥.94). Conclusions CMC waveform comparisons were similar relative to the joint measured to previously published reports of between-sessions reliability of sagittal- and frontal-plane biomechanics performed at a single institution. Continued research is needed to further standardize technology and methods to help ensure that highly

  9. Risk Factors for Maternal Mortality in Rural Tigray, Northern Ethiopia: A Case-Control Study

    PubMed Central

    Godefay, Hagos; Byass, Peter; Graham, Wendy J.; Kinsman, John; Mulugeta, Afework

    2015-01-01

    Background Maternal mortality continues to have devastating impacts in many societies, where it constitutes a leading cause of death, and thus remains a core issue in international development. Nevertheless, individual determinants of maternal mortality are often unclear and subject to local variation. This study aims to characterise individual risk factors for maternal mortality in Tigray, Ethiopia. Methods A community-based case-control study was conducted, with 62 cases and 248 controls from six randomly-selected rural districts. All maternal deaths between May 2012 and September 2013 were recruited as cases and a random sample of mothers who delivered in the same communities within the same time period were taken as controls. Multiple logistic regression was used to identify independent determinants of maternal mortality. Results Four independent individual risk factors, significantly associated with maternal death, emerged. Women who were not members of the voluntary Women’s Development Army were more likely to experience maternal death (OR 2.07, 95% CI 1.04–4.11), as were women whose husbands or partners had below-median scores for involvement during pregnancy (OR 2.19, 95% CI 1.14–4.18). Women with a pre-existing history of other illness were also at increased risk (OR 5.58, 95% CI 2.17–14.30), as were those who had never used contraceptives (OR 2.58, 95% CI 1.37–4.85). Previous pregnancy complications, a below-median number of antenatal care visits and a woman’s lack of involvement in health care decision making were significant bivariable risks that were not significant in the multivariable model. Conclusions The findings suggest that interventions aimed at reducing maternal mortality need to focus on encouraging membership of the Women’s Development Army, enhancing husbands’ involvement in maternal health services, improving linkages between maternity care and other disease-specific programmes and ensuring that women with previous

  10. Case-Control Study of Enteropathogens Associated with Childhood Diarrhea in Dhaka, Bangladesh

    PubMed Central

    Albert, M. John; Faruque, A. S. G.; Faruque, S. M.; Sack, R. B.; Mahalanabis, D.

    1999-01-01

    The International Centre for Diarrhoeal Disease Research, Bangladesh, is a major center for research into diarrheal diseases. The center treats more than 100,000 patients a year. To obtain useful information representative of all patients, a surveillance system in which a 4% systematic sample of all patients is studied in detail, including etiological agents of diarrhea, was installed in October 1979. The first paper on etiology for the surveillance patients was published in 1982, which identified a potential enteric pathogen in 66% of patients. In subsequent years, several new agents of diarrhea have been identified. To assess the importance of a broader spectrum of diarrheal agents including the ones identified relatively recently, we studied 814 children with diarrhea. The children were up to 5 years of age and were part of the surveillance system. They were matched with an equal number of community controls without diarrhea. The study was conducted from February 1993 to June 1994. A potential enteric pathogen was isolated from 74.8% of diarrheal children and 43.9% of control children (P = 0.0001). Even though the first study was not a case-control study, it identified rotavirus, Campylobacter jejuni, enterotoxigenic Escherichia coli, Shigella spp., and Vibrio cholerae O1 as major pathogens. The present study identified these pathogens as being significantly associated with diarrhea. In addition, the study also identified six additional agents, including enteropathogenic E. coli, Aeromonas spp., V. cholerae O139, enterotoxigenic Bacteroides fragilis, Clostridium difficile, and Cryptosporidium parvum, as being significantly associated with diarrhea. Plesiomonas shigelloides, Salmonella spp., diffusely adherent E. coli, enteroaggregative E. coli, Entamoeba histolytica, and Giardia lamblia were not significantly associated with diarrhea. Enteroinvasive E. coli, enterohemorrhagic E. coli, and Cyclospora cayetanensis were not detected in any of the children. The

  11. Healthy Eating Index in Patients With Cataract: A Case-Control Study

    PubMed Central

    Ghanavati, Matin; Behrooz, Maryam; Rashidkhani, Bahram; Ashtray-Larky, Damoon; Zameni, Seyed Davood; Alipour, Meysam

    2015-01-01

    Background: Nutritional factors play an important role in cataract disease and the healthy eating index (HEI) is a unique approach to study the relationships between diet and diseases. Objectives: The current study aimed to evaluate and compare healthy eating index among the patients with cataract and healthy individuals. Patients and Methods: This case-control study was conducted on 97 patients with cataract and 198 healthy people (as a control group) in Iran. Individuals were selected by the convenience sampling method and the food frequency questionnaire (FFQ) was completed for them. At first, HEI was calculated and then the HEI scores were compared in cataract patients and healthy individuals. Results: The analysis of FFQ showed that the scores of vegetables (7.81 v. 10), nutritional variation (5.5 v. 7) and sodium (2 v. 6) groups (P < 0.001) were significantly lower among the patients with cataract than the healthy individuals. Also this significant difference was observed in the scores of total HEI and fruits (respectively 73.26 v.79.30 and 7.1 v. 9.8) (P < 0.01). On the other hand, the scores of saturated fatty acids (10 v. 9; P = 0.02), total fat (8 v. 7; P = 0.004) and cereals (10 v. 10; P < 0.001) were higher among the patients with cataract than the healthy individuals. The comparison of dietary intake among all types of cataract shows that the scores of the meat group were significantly higher in the patients with nuclear cataract and mixed cataract than the ones with posterior cataract (respectively 9.4 v. 6.5 and 9 v. 6.5) (P = 0.02). In addition, after adjusting the confounding factors the results showed that the HEI high score was associated with reducing the risk of coming down with cataract (OR = 0.18, CI: 95%, P < 0.001, 0.08 - 0.41). Conclusions: The results of the current study suggest that increasing the quality of the diet calculated according to HEI can reduce the risk of coming down with cataract. PMID:26568860

  12. GWIS - model-free, fast and exhaustive search for epistatic interactions in case-control GWAS

    PubMed Central

    2013-01-01

    Background It has been hypothesized that multivariate analysis and systematic detection of epistatic interactions between explanatory genotyping variables may help resolve the problem of "missing heritability" currently observed in genome-wide association studies (GWAS). However, even the simplest bivariate analysis is still held back by significant statistical and computational challenges that are often addressed by reducing the set of analysed markers. Theoretically, it has been shown that combinations of loci may exist that show weak or no effects individually, but show significant (even complete) explanatory power over phenotype when combined. Reducing the set of analysed SNPs before bivariate analysis could easily omit such critical loci. Results We have developed an exhaustive bivariate GWAS analysis methodology that yields a manageable subset of candidate marker pairs for subsequent analysis using other, often more computationally expensive techniques. Our model-free filtering approach is based on classification using ROC curve analysis, an alternative to much slower regression-based modelling techniques. Exhaustive analysis of studies containing approximately 450,000 SNPs and 5,000 samples requires only 2 hours using a desktop CPU or 13 minutes using a GPU (Graphics Processing Unit). We validate our methodology with analysis of simulated datasets as well as the seven Wellcome Trust Case-Control Consortium datasets that represent a wide range of real life GWAS challenges. We have identified SNP pairs that have considerably stronger association with disease than their individual component SNPs that often show negligible effect univariately. When compared against previously reported results in the literature, our methods re-detect most significant SNP-pairs and additionally detect many pairs absent from the literature that show strong association with disease. The high overlap suggests that our fast analysis could substitute for some slower alternatives

  13. Blood transfusion costs: a multicenter study.

    PubMed

    Forbes, J M; Anderson, M D; Anderson, G F; Bleecker, G C; Rossi, E C; Moss, G S

    1991-05-01

    The cost of delivering a unit of blood (whole blood or red cells) to a hospitalized patient was examined in 19 United States teaching hospitals. The average hospital acquisition cost was calculated by using the prices charged by regional blood centers for blood products. To this cost was added an estimate of costs incurred by hospitals for handling, testing, and administering blood. Across study sites, the average hospital cost per unit transfused was $155 and the average charge to the patient was $219. Acquisition cost, the price that hospitals pay for blood, was 37 percent of the total cost to the hospital; the other 63 percent of the hospital cost included costs for blood bank handling (13%), laboratory tests (43%), and blood administration (7%). Significant variations in blood transfusion cost were found within our sample. Most of the variability can be attributed to geographic location of the blood supply source, type of red cell product transfused, prices charged by blood transfusion services, and the frequency of laboratory tests. The results of this transfusion cost study may be helpful in determining the costs of health care delivery, especially when blood transfusions are indicated. PMID:2020994

  14. Modelling of occupational respirable crystalline silica exposure for quantitative exposure assessment in community-based case-control studies.

    PubMed

    Peters, Susan; Vermeulen, Roel; Portengen, Lützen; Olsson, Ann; Kendzia, Benjamin; Vincent, Raymond; Savary, Barbara; Lavoué, Jérôme; Cavallo, Domenico; Cattaneo, Andrea; Mirabelli, Dario; Plato, Nils; Fevotte, Joelle; Pesch, Beate; Brüning, Thomas; Straif, Kurt; Kromhout, Hans

    2011-11-01

    We describe an empirical model for exposure to respirable crystalline silica (RCS) to create a quantitative job-exposure matrix (JEM) for community-based studies. Personal measurements of exposure to RCS from Europe and Canada were obtained for exposure modelling. A mixed-effects model was elaborated, with region/country and job titles as random effect terms. The fixed effect terms included year of measurement, measurement strategy (representative or worst-case), sampling duration (minutes) and a priori exposure intensity rating for each job from an independently developed JEM (none, low, high). 23,640 personal RCS exposure measurements, covering a time period from 1976 to 2009, were available for modelling. The model indicated an overall downward time trend in RCS exposure levels of -6% per year. Exposure levels were higher in the UK and Canada, and lower in Northern Europe and Germany. Worst-case sampling was associated with higher reported exposure levels and an increase in sampling duration was associated with lower reported exposure levels. Highest predicted RCS exposure levels in the reference year (1998) were for chimney bricklayers (geometric mean 0.11 mg m(-3)), monument carvers and other stone cutters and carvers (0.10 mg m(-3)). The resulting model enables us to predict time-, job-, and region/country-specific exposure levels of RCS. These predictions will be used in the SYNERGY study, an ongoing pooled multinational community-based case-control study on lung cancer. PMID:22001827

  15. Multi-center, multi-topic heart sound databases and their applications.

    PubMed

    Xie, Meilan; Xiao, Shouzhong; Liu, Tianhu; Yi, Qijian; You, Fengzhi; Guo, Xingming; Shao, Yong; Huo, Junmimg; Du, Deqi; Xu, Dongmei; Wu, Wenzhu; Xiao, Zifu; Yang, Yong; Guo, Weizhen

    2012-02-01

    This paper describes a large resource of multi-center and multi-topic heart sound databases, which were based on the measured data from more than 9,000 heart sound samples (saved in WAV file format). According to different research topics, these samples were respectively stored in different folders (corresponding to different research topics and distributed over various cooperative research centers), most of which as subfolds were stored in a pooled folder in the principal center. According to different research topics, the measured data from these samples were used to create different databases. Relevant data for a specific topic can be pooled in a large database for further analysis. This resource is shared by members of related centers for their own specific topic. The applications of this resource include evaluation of cardiac safety of pregnant women, evaluation of cardiac reserve for children, athletes, addicts, astronauts, and general populations, as well as studies on a bedside method for evaluating cardiac energy, reversal of S1-S2 ratio, etc. PMID:20703751

  16. Review of rank-based procedures for multicenter clinical trials.

    PubMed

    Rashid, M Mushfiqur; McKean, Joseph W; Kloke, John D

    2013-01-01

    This article reviews nonparametric alternatives to the mixed model normal theory analysis for the analyses of multicenter clinical trials. Under a mixed model, the traditional analysis is based on maximum likelihood theory under normal errors. This analysis, though, is not robust to outliers. Robust, rank-based, Wilcoxon-type procedures are reviewed for a multicenter clinical trial for the mixed model but without the assumption of normality. These procedures retain the high efficiency of Wilcoxon methods for simple location problems and are based on a fitting criterion which is robust to outliers in response space. A simple weighting scheme can be employed so that the procedures are robust to outliers in factor (design) space as well as response space. These rank-based analyses offer a complete analysis, including estimation of fixed effects and their standard errors, and tests of linear hypotheses. Both rank-based estimates of contrasts and individual treatment effects are reviewed. We illustrate the analyses using real data from a clinical trial. PMID:24138428

  17. Subregional Basal Forebrain Atrophy in Alzheimer's Disease: A Multicenter Study

    PubMed Central

    Kilimann, Ingo; Grothe, Michel; Heinsen, Helmut; Alho, Eduardo Joaquim Lopez; Grinberg, Lea; Amaro, Edson; dos Santos, Gláucia Aparecida Bento; da Silva, Rafael Emídio; Mitchell, Alex J.; Frisoni, Giovanni B.; Bokde, Arun L.W.; Fellgiebel, Andreas; Filippi, Massimo; Hampel, Harald; Klöppel, Stefan; Teipel, Stefan J.

    2014-01-01

    Histopathological studies in Alzheimer's disease (AD) suggest severe and region-specific neurodegeneration of the basal forebrain cholinergic system (BFCS). Here, we studied the between-center reliability and diagnostic accuracy of MRI-based BFCS volumetry in a large multicenter data set, including participants with prodromal (n = 41) or clinically manifest AD (n = 134) and 148 cognitively healthy controls. Atrophy was determined using voxel-based and region-of-interest based analyses of high-dimensionally normalized MRI scans using a newly created map of the BFCS based on postmortem in cranio MRI and histology. The AD group showed significant volume reductions of all subregions of the BFCS, which were most pronounced in the posterior nucleus basalis Meynert (NbM). The mild cognitive impairment-AD group showed pronounced volume reductions in the posterior NbM, but preserved volumes of anterior-medial regions. Diagnostic accuracy of posterior NbM volume was superior to hippocampus volume in both groups, despite higher multicenter variability of the BFCS measurements. The data of our study suggest that BFCS morphometry may provide an emerging biomarker in AD. PMID:24503619

  18. Multicentered black holes with a negative cosmological constant

    NASA Astrophysics Data System (ADS)

    Chimento, Samuele; Klemm, Dietmar

    2014-01-01

    We present a recipe that allows us to construct multicentered black holes embedded in an arbitrary Friedmann-Lemaître-Robertson-Walker (FLRW) universe. These solutions are completely determined by a function satisfying the conformal Laplace equation on the spatial slices E3, S3, or H3. Since anti-de Sitter (AdS) space can be written in FLRW coordinates, this includes as a special case multicentered black holes in AdS, in the sense that, far away from the black holes, the energy density and the pressure approach the values given by a negative cosmological constant. We study in some detail the physical properties of the single-centered asymptotically AdS case, which does not coincide with the usual Reissner-Nordström-AdS black hole, but is highly dynamical. In particular, we determine the curvature singularities and trapping horizons of this solution, compute the surface gravity of the trapping horizons, and show that the generalized first law of black hole dynamics proposed by Hayward holds in this case. It turns out that the spurious big bang/big crunch singularities that appear when one writes AdS in FLRW form become real in the presence of these dynamical black holes. This implies that actually only one point of the usual conformal boundary of AdS survives in the solutions that we construct. Finally, a generalization to arbitrary dimension is also presented.

  19. Chest radiographic data acquisition and quality assurance in multicenter studies

    PubMed Central

    Schluchter, Mark; Wood, Beverly P.; Berdon, Walter E.; Boechat, M. Ines; Easley, Kirk A.; Meziane, Moulay; Mellins, Robert B.; Norton, Karen I.; Singleton, Edward; Trautwein, Lynn

    2015-01-01

    Background Multicenter studies rely on data derived from different institutions. Forms can be designed to standardize the reporting process allowing reliable comparison of data. Objective The purpose of the report is to provide a standardized method, developed as a part of a multicenter study of vertically transmitted HIV, for assessing chest radiographic results. Materials and methods Eight hundred and five infants and children were studied at five centers; 3057 chest radiographs were scored. Data were entered using a forced-choice, graded response for 12 findings. Quality assurance measures and inter- rater agreement statistics are reported. Results The form used for reporting chest radiographic results is presented. Inter-rater agreement was moderate to high for most findings, with the best correlation reported for the presence of bronchovascular markings and/or reticular densities addressed as a composite question (kappa = 0.71). The presence of nodular densities (kappa = 0.56) and parenchymal consolidation (kappa = 0.57) had moderate agreement. Agreement for lung volume was low. Conclusion The current tool, developed for use in the pediatric population, is applicable to any study involving the assessment of pediatric chest radiographs for a large population, whether at one or many centers. PMID:9361051

  20. Pseudomonas aeruginosa and Periodontal Pathogens in the Oral Cavity and Lungs of Cystic Fibrosis Patients: a Case-Control Study.

    PubMed

    Rivas Caldas, Rocio; Le Gall, Florence; Revert, Krista; Rault, Gilles; Virmaux, Michèle; Gouriou, Stephanie; Héry-Arnaud, Geneviève; Barbier, Georges; Boisramé, Sylvie

    2015-06-01

    Cystic fibrosis (CF) is the most frequent lethal genetic disease in the Caucasian population. Lung destruction is the principal cause of death by chronic Pseudomonas aeruginosa colonization. There is a high prevalence of oropharyngeal anaerobic bacteria in sputum of CF patients. This study was carried out due to the lack of results comparing subgingival periodontal pathogenic bacteria between the oral cavity and lungs in patients with CF in relation with P. aeruginosa presence. Our first goal was to detect P. aeruginosa in oral and sputum samples by culture and molecular methods and to determine clonality of isolates. In addition, subgingival periodontal anaerobic bacteria were searched for in sputum. A cross-sectional pilot case-control study was conducted in the CF Reference Center in Roscoff, France. Ten CF patients with a ΔF508 homozygous mutation (5 chronically colonized [CC] and 5 not colonized [NC]) were enrolled. P. aeruginosa was detected in saliva, sputum, and subgingival plaque samples by real-time quantitative PCR (qPCR). Subsequently, periodontal bacteria were also detected and quantified in subgingival plaque and sputum samples by qPCR. In CC patients, P. aeruginosa was recovered in saliva and subgingival plaque samples. Sixteen P. aeruginosa strains were isolated in saliva and sputum from this group and compared by pulsed-field gel electrophoresis (PFGE). Subgingival periodontal anaerobic bacteria were found in sputum samples. A lower diversity of these species was recovered in the CC patients than in the NC patients. The presence of the same P. aeruginosa clonal types in saliva and sputum samples underlines that the oral cavity is a possible reservoir for lung infection. PMID:25854483

  1. Nested case-control study in a serological survey to evaluate the effectiveness of a Chagas disease control programme in Brazil.

    PubMed Central

    Carneiro, M.; Moreno, E. C.; Antunes, C. M.

    2001-01-01

    OBJECTIVE: To identify risk factors associated with Trypanosoma cruzi infections in areas under surveillance in the State of Minas Gerais, Brazil. METHODS: A model using a nested case-control design incorporated within a serological survey of schoolchildren which was employed to evaluate the effectiveness of the Chagas disease control programme. FINDINGS: In a sample of 40,374 schoolchildren (aged 7-14 years) surveyed, 16 children tested positive for T. cruzi antibody (by indirect immunofluorescence and indirect haemagglutination). In the case-control study, each case was randomly matched to three seronegative controls (classroom and age +/- 1 year). Compared to controls, T. cruzi-seropositive children were more likely to have a seropositive mother (odds ratio (OR) = 6.8; 95% confidence interval (CI) = 0.71-63.9) or a seropositive family member (OR = 8.6; 95% CI = 1.0-75.5). CONCLUSION: Use of the nested case-control model in a sero-epidemiological survey to evaluate risk factors for T. cruzi transmission was adequate for assessing the effectiveness of a Chagas disease control programme. PMID:11417036

  2. Food- and water-borne disease: using case control studies to estimate the force of infection that accounts for primary, sporadic cases.

    PubMed

    Smith, G

    2013-06-01

    Disease models which take explicit account of heterogeneities in the risk of infection offer significant advantages over models in which the risk of infection is assumed to be uniform across all hosts. However, estimating the incidence rate (force of infection) in the different at-risk (exposure) groups is no easy matter. Classically, epidemiologists differentiate groups of hosts with different infection-risks according to their exposure to putative explanatory risk factors. The importance of these risk factors is assessed by case-control studies, in which the measure of effect (the difference in disease occurrence between one population and another) is the odds ratio. This paper describes for the first time how - and under what circumstances - the incidence in these different exposure groups can be estimated from odds ratios derived from case control studies in which controls have been selected by density sampling. This new estimation technique can be applied to any transmission modality but is especially useful in the case of models of food- and water-borne disease for which the case control literature represents a vast and, as yet, untapped resource. The paper finishes with a worked example using one of the most common of all food- and water-borne pathogens, Toxoplasma gondii. PMID:23746800

  3. Recall bias in melanoma risk factors and measurement error effects: a nested case-control study within the Norwegian Women and Cancer Study.

    PubMed

    Parr, Christine L; Hjartåker, Anette; Laake, Petter; Lund, Eiliv; Veierød, Marit B

    2009-02-01

    Case-control studies of melanoma have the potential for recall bias after much public information about the relation with ultraviolet radiation. Recall bias has been investigated in few studies and only for some risk factors. A nested case-control study of recall bias was conducted in 2004 within the Norwegian Women and Cancer Study: 208 melanoma cases and 2,080 matched controls were invited. Data were analyzed for 162 cases (response, 78%) and 1,242 controls (response, 77%). Questionnaire responses to several host factors and ultraviolet exposures collected at enrollment in 1991-1997 and in 2004 were compared stratified on case-control status. Shifts in responses were observed among both cases and controls, but a shift in cases was observed only for skin color after chronic sun exposure, and a larger shift in cases was observed for nevi. Weighted kappa was lower for cases than for controls for most age intervals of sunburn, sunbathing vacations, and solarium use. Differences in odds ratio estimates of melanoma based on prospective and retrospective measurements indicate measurement error that is difficult to characterize. The authors conclude that indications of recall bias were found in this sample of Norwegian women, but that the results were inconsistent for the different exposures. PMID:19011116

  4. Is Alpha-1 Antichymotrypsin Gene Polymorphism a Risk Factor for Primary Intracerebral Hemorrhage? A Case-Control Study and Meta-Analysis

    PubMed Central

    Hu, Xin; Li, Yunke; Li, Hao; Fang, Yuan; Liu, Ming; You, Chao

    2015-01-01

    Background Alpha-1 antichymotrypsin (ACT) signal peptide A/T polymorphism has been suggested to play a role in various brain diseases with arterial wall pathology. We conducted a case-control study and a meta-analysis to evaluate the association between this polymorphism and risk of primary intracerebral hemorrhage. Material/Methods A total of 188 patients and 200 age- and sex-matched healthy controls were enrolled in our case-control study. The ACT polymorphism was genotyped by PCR-LDR. Further meta-analysis was conducted by searching literature from PUBMED, EMBASE, and Chinese National Knowledge Infrastructure databases until December 2014, then combining data using STATA10.0. Results Similar genotype distribution was detected between PICH patients and healthy controls (p=0.523). Further analysis based on hypertension and location of hemorrhage did not observe significant association. Multiple logistic regression analysis also failed to identify ACT polymorphism as an independent risk factor for PICH. With regard to meta-analysis, a total of 6 case-control studies including 932 PICH patients and 1140 controls were enrolled. Pooled ORs failed to detect a significant association of ACT signal peptide A/T polymorphism with PICH (dominant model: OR=1.03, 95%CI=0.72–1.46; recessive model: OR=1.08, 95%CI=0.88–1.32). Subgroup analysis based on hypertension revealed no association in hypertensive PICH or in normotensive PICH. Conclusions Our case-control study in a Chinese population did not detect a significant association between ACT signal peptide A/T polymorphism and PICH. Moreover, meta-analysis combining data from relevant studies failed to provide evidence for the association. Further well-designed studies with larger sample sizes are warranted to verify our findings. PMID:26210716

  5. Bayes and empirical Bayes methods for reduced rank regression models in matched case-control studies

    PubMed Central

    Zhou, Qin; Lan, Qing; Rothman, Nathaniel; Langseth, Hilde; Engel, Lawrence S.

    2015-01-01

    Summary Matched case-control studies are popular designs used in epidemiology for assessing the effects of exposures on binary traits. Modern studies increasingly enjoy the ability to examine a large number of exposures in a comprehensive manner. However, several risk factors often tend to be related in a non-trivial way, undermining efforts to identify the risk factors using standard analytic methods due to inflated type I errors and possible masking of effects. Epidemiologists often use data reduction techniques by grouping the prognostic factors using a thematic approach, with themes deriving from biological considerations. We propose shrinkage type estimators based on Bayesian penalization methods to estimate the effects of the risk factors using these themes. The properties of the estimators are examined using extensive simulations. The methodology is illustrated using data from a matched case-control study of polychlorinflated biphenyls in relation to the etiology of non-Hodgkin’s lymphoma. PMID:26575519

  6. Bayes and empirical Bayes methods for reduced rank regression models in matched case-control studies.

    PubMed

    Satagopan, Jaya M; Sen, Ananda; Zhou, Qin; Lan, Qing; Rothman, Nathaniel; Langseth, Hilde; Engel, Lawrence S

    2016-06-01

    Matched case-control studies are popular designs used in epidemiology for assessing the effects of exposures on binary traits. Modern studies increasingly enjoy the ability to examine a large number of exposures in a comprehensive manner. However, several risk factors often tend to be related in a nontrivial way, undermining efforts to identify the risk factors using standard analytic methods due to inflated type-I errors and possible masking of effects. Epidemiologists often use data reduction techniques by grouping the prognostic factors using a thematic approach, with themes deriving from biological considerations. We propose shrinkage-type estimators based on Bayesian penalization methods to estimate the effects of the risk factors using these themes. The properties of the estimators are examined using extensive simulations. The methodology is illustrated using data from a matched case-control study of polychlorinated biphenyls in relation to the etiology of non-Hodgkin's lymphoma. PMID:26575519

  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. Case-control study of renal cell carcinoma in relation to occupation, smoking, and alcohol consumption

    SciTech Connect

    Brownson, R.C.

    1988-05-01

    A case-control study based on data from a cancer registry was conducted to evaluate the effects of smoking, alcohol use, and occupation on renal cell cancer risk. Information was obtained for 326 male and female cases and 978 age- and sex-matched controls. Elevated risks were identified for cigarette smokers and for men employed as truck drivers. No relationship between alcohol consumption and renal cancer was observed.

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

    PubMed Central

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

    2014-01-01

    Both genetic and non-genetic environmental factors are involved in the etiology of neural tube defects (NTD) which affect 0.5-2/1000 pregnancies worldwide. This study aimed to explore the risk factors for the development of NTD in Saudi population, and highlight identifiable and preventable causes. Similar studies are scarce in similar populations ofthe Arabian Peninsula and North Africa. This is an unmatched concurrent case-control study including NTD cases born at King Khalid University Hospital, Riyadh during a 4-year period (2002-2006). The case-control study included 25 cases and 125 controls (case: control ratio of 1:5). Years of formal education, employment, household environment (including availability of air conditioning) and rate of parental consanguinity did not differ between mothers of cases and controls. Significantly higher proportion of mothers of cases had history of stillbirth compared to control mothers (16% vs 4.1%, P=0.02). Also family history of hydrocephalus and congenital anomalies were more prevalent in cases than controls (P values=0.0000 and 0.003, respectively). There was significant protective effect of periconceptional folic acid consumption both prior to conception (OR 0.02, 95% CI 0.00-0.07) and during the first 6 weeks of conception (OR 0.13, 95% CI 0.04-0.39). Further research, including a larger cohort, is required to enable ascertainment of gene-nutrient and gene environment interactions associated with NTD in Saudi Arabia. PMID:27493405

  10. Drug induced immune haemolytic anaemia in the Berlin Case-Control Surveillance Study.

    PubMed

    Garbe, Edeltraut; Andersohn, Frank; Bronder, Elisabeth; Klimpel, Andreas; Thomae, Michael; Schrezenmeier, Hubert; Hildebrandt, Martin; Späth-Schwalbe, Ernst; Grüneisen, Andreas; Mayer, Beate; Salama, Abdulgabar; Kurtal, Hanife

    2011-09-01

    Drug-induced immune haemolytic anaemia is a rare but serious condition. This study investigated the possibility of drug aetiology of immune haemolytic anaemia (IHA) in 134 patients with new onset of IHA who were identified in the Berlin Case-Control Surveillance Study between 2000 and 2009. Single drugs related to IHA in three or more patients and assessed more than once as a certain or probable cause of IHA in a standardized causality assessment included diclofenac, fludarabine, oxaliplatin, ceftriaxone and piperacillin. In a case-control study including all 124 IHA cases developed in outpatient care and 731 controls, significantly increased odds ratios (OR) were observed for beta-lactam antibiotics (OR=8·8; 95% confidence interval [CI] 3·2-25·2), cotrimoxazole (OR=6·5; CI 1·1-37·9), ciprofloxacin (OR=6·9, CI 1·3-38·5), fludarabine (OR=22·2; CI: 2·8-454·5) and lorazepam (OR=5·3; CI: 1·2-21·2). Excluding new onset cases with a chronic IHA disease course, an increased risk became also apparent for diclofenac with an OR of 3·1 (CI 1·3-7·0). This is the first case-control study investigating drugs as risk factors for IHA. It corroborates an increased risk for several drugs that have been implicated as a cause of IHA in the standardized causality assessment of individual cases. PMID:21749359

  11. Determining exposure underreporting in pharmacoepidemiologic case-control studies: methods and example.

    PubMed

    Lane, D A; Kramer, M S

    1999-12-01

    Many pharmacoepidemiologic case-control studies have to rely on what their subjects relate about the drugs to which they have been exposed and the durations of exposure. There is often good reason to suppose that not all exposures are actually reported and to suspect reporting rates may differ between cases and controls. We introduce two procedures designed to determine the extent of underreporting of exposures. These procedures make use of data from the case-control study itself, as well as sales, demographic and market research data for a reference population to which study subjects belong. We apply these procedures to data from the International Primary Pulmonary Hypertension Study (IPPHS) linking anorexigens with PPH. We show that exposures to the anorectic agent dexfenfluramine beginning in or before 1989 were highly significantly underrepresented in the data for IPPHS controls, relative to exposures beginning after 1989 (P<0.01); there is no corresponding evidence for relative underrepresentation of early exposure for IPPHS cases. However, data on control exposures from 1990 to 1992 are consistent with the hypothesis that these exposures were not underreported to the IPPHS. Subject to certain key modeling assumptions and the availability of some supplemental data, it is possible to investigate the extent of underreporting of exposure in a pharmacoepidemiologic case-control study and in particular to determine if study results are likely to have been affected by recall bias. PMID:10580792

  12. ALS Multicenter Cohort Study of Oxidative Stress (ALS COSMOS): The study methodology, recruitment, and baseline demographic and disease characteristics

    PubMed Central

    Mitsumoto, Hiroshi; Factor-Litvak, Pam; Andrews, Howard; Goetz, Raymond R.; Andrews, Leslie; Rabkin, Judith G.; McElhiney, Martin; Nieves, Jeri; Santella, Regina M.; Murphy, Jennifer; Hupf, Jonathan; Singleton, Jess; Merle, David; Kilty, Mary; Heitzman, Daragh; Bedlack, Richard S.; Miller, Robert G; Katz, Jonathan S.; Forshew, Dallas; Barohn, Richard J.; Sorenson, Eric J.; Oskarsson, Bjorn; Filho, J Americo M. Fernandes; Kasarskis, Edward J.; Lomen-Hoerth, Catherine; Mozaffar, Tahseen; Rollins, Yvonne D.; Nations, Sharon P.; Swenson, Andrea J.; Shefner, Jeremy M.; Andrews, Jinsy A.; Koczon-Jaremko, Boguslawa A.

    2015-01-01

    Objective In a multicenter study of newly diagnosed ALS patients without a reported family history of ALS, we are prospectively investigating whether markers of oxidative stress (OS) are associated with disease progression. Methods An extensive structured telephone interview ascertained environmental, lifestyle, dietary and psychological risk factors associated with OS. Detailed assessments were performed at baseline and at 3 to 6 month intervals during the ensuing 30 months. Our biorepository includes DNA, plasma, urine, and skin. Results 355 patients were recruited. Subjects were enrolled over a 36 month-period at 16 sites. To meet the target number of subjects, the recruitment period was prolonged and additional sites were included. Demographic and disease characteristics were similar between 477 eligible/non-enrolled and enrolled patients, with the only difference being type of health insurance among enrolled patients. Sites were divided into 3 groups by the number of enrolled subjects. Comparing these 3 groups, the Columbia site had fewer “definite ALS” diagnoses. Conclusion This is the first prospective, interdisciplinary, in-depth, multicenter epidemiological investigation of OS related to ALS progression and was accomplished by an aggressive recruitment process. The baseline demographic and disease features of the study sample are now fully characterized. PMID:24564738

  13. Prediction of accrual closure date in multi-center clinical trials with discrete-time Poisson process models

    PubMed Central

    Tang, Gong; Kong, Yuan; Chang, Chung-Chou Ho; Kong, Lan; Costantino, Joseph P.

    2016-01-01

    In a phase III multi-center cancer clinical trial or large public health studies, sample size is predetermined to achieve desired power and study participants are enrolled from tens or hundreds of participating institutions. As the accrual is closing to the target size, the coordinating data center needs to project the accrual closure date based on the observed accrual pattern and notify the participating sites several weeks in advance. In the past, projections were simply based on some crude assessment and conservative measures were incorporated in order to achieve the target accrual size. This approach often resulted in excessive accrual size and subsequently unnecessary financial burden on the study sponsors. Here we proposed a discrete-time Poisson process-based method to estimate the accrual rate at time of projection and subsequently the trial closure date. To ensure that target size would be reached with high confidence, we also proposed a conservative method for the closure date projection. The proposed method was illustrated through the analysis of the accrual data of NSABP trial B-38. The results showed that application of proposed method could help to save considerable amount of expenditure in patient management without compromising the accrual goal in multi-center clinical trials. PMID:22411544

  14. Prevalence of Toxoplasma infection in veterinary laboratory sciences students comparing to ordinary people: a case-control study.

    PubMed

    Sadaghian, Mohammad; Jafari, Rasool

    2016-09-01

    Toxoplasma gondii causes the foremost widespread protozoan infection with a broad variety of host range, which consists of regarding of almost all warm-blooded vertebrates. There are some opinions concerning the probable occupational influence on infections to Toxoplasma in veterinary services personnel. The present study aimed to examine influence of studying in veterinary laboratory sciences as a risk factor on the prevalence rate of Toxoplasma infection in the students. In this case-control study, 80 blood samples were taken from veterinary laboratory sciences students (VLSS) as a case group and 80 blood samples from ordinary people of general population as a control group with the relatively same age, gender and health condition. Anti-Toxoplasma IgG levels in the serum samples were determined using quantitative ELISA method. According to the results, 27 (33.75 %) out of 80 samples of the cases group and also 29 (36.2 %) out of 80 samples of the control group were infected by the parasite. No statistically significant difference observed in the infection rate between the case and control groups (P = 0.740, OR 0.931; 95 % CI 0.61, 1.421). The mean serum antibody concentration in infected subjects of case and control groups showed no statistically significant difference (P = 0.618, t = 0.502). Normality of the data was assumed using Kolmogorov-Smirnov test (P = 0.806, Z = 0.641). Based on the results, in veterinary laboratory science students, toxoplasmosis is not related to their career and also the subjects of this group as the other people have the same risk to infect by this protozoan parasite. PMID:27605781

  15. The Procalcitonin And Survival Study (PASS) – A Randomised multi-center investigator-initiated trial to investigate whether daily measurements biomarker Procalcitonin and pro-active diagnostic and therapeutic responses to abnormal Procalcitonin levels, can improve survival in intensive care unit patients. Calculated sample size (target population): 1000 patients

    PubMed Central

    Jensen, Jens-Ulrik; Lundgren, Bettina; Hein, Lars; Mohr, Thomas; Petersen, Pernille L; Andersen, Lasse H; Lauritsen, Anne Ø; Hougaard, Sine; Mantoni, Teit; Bømler, Bonnie; Thornberg, Klaus J; Thormar, Katrin; Løken, Jesper; Steensen, Morten; Carl, Peder; Petersen, J Asger; Tousi, Hamid; Søe-Jensen, Peter; Bestle, Morten; Hestad, Søren; Andersen, Mads H; Fjeldborg, Paul; Larsen, Kim M; Rossau, Charlotte; Thomsen, Carsten B; Østergaard, Christian; Kjær, Jesper; Grarup, Jesper; Lundgren, Jens D

    2008-01-01

    Background Sepsis and complications to sepsis are major causes of mortality in critically ill patients. Rapid treatment of sepsis is of crucial importance for survival of patients. The infectious status of the critically ill patient is often difficult to assess because symptoms cannot be expressed and signs may present atypically. The established biological markers of inflammation (leucocytes, C-reactive protein) may often be influenced by other parameters than infection, and may be unacceptably slowly released after progression of an infection. At the same time, lack of a relevant antimicrobial therapy in an early course of infection may be fatal for the patient. Specific and rapid markers of bacterial infection have been sought for use in these patients. Methods Multi-centre randomized controlled interventional trial. Powered for superiority and non-inferiority on all measured end points. Complies with, "Good Clinical Practice" (ICH-GCP Guideline (CPMP/ICH/135/95, Directive 2001/20/EC)). Inclusion: 1) Age ≥ 18 years of age, 2) Admitted to the participating intensive care units, 3) Signed written informed consent. Exclusion: 1) Known hyper-bilirubinaemia. or hypertriglyceridaemia, 2) Likely that safety is compromised by blood sampling, 3) Pregnant or breast feeding. Computerized Randomisation: Two arms (1:1), n = 500 per arm: Arm 1: standard of care. Arm 2: standard of care and Procalcitonin guided diagnostics and treatment of infection. Primary Trial Objective: To address whether daily Procalcitonin measurements and immediate diagnostic and therapeutic response on day-to-day changes in procalcitonin can reduce the mortality of critically ill patients. Discussion For the first time ever, a mortality-endpoint, large scale randomized controlled trial with a biomarker-guided strategy compared to the best standard of care, is conducted in an Intensive care setting. Results will, with a high statistical power answer the question: Can the survival of critically ill

  16. Association of Smoking With Semen Quality and µ-Calpain Level in Normospermia: A Case-Control Study

    PubMed Central

    Ashtary-Larky, Damoon; Ghaffari, Mohammad Ali; Noorbehbahani, Mozhgan; Alipour, Meysam

    2016-01-01

    Objective: Calpains are a family of Ca2+ dependent proteases. There is some evidence that calpains involved in fusion process that occurs between spermatozoa and the oocyte. The current study aimed to investigate the association of smoking with semen quality and µ-calpain level. Materials and methods: This case-control study was conducted on 117 normospermia males between June 2013 and march 2014 in Jahad Laboratory in ahvaz, Iran. The semen samples were collected from male smokers (n = 50) and non-smokers (n = 67). We divided these participants as light, moderate, or heavy smokers based on their cigarettes per day (CPD). ELISA assays were used to measure µ-calpain concentration. All semen samples were analyzed according to World Health Organization guidelines. Results: The analysis of semen showed the volume, concentration, motility and morphology of semen were significantly lower among the smoker men than the non-smoker men. Also this significant difference was observed based on the number (light, moderate and heavy smokers) and duration (short term and long term smoker) of smoking. Although, showed no significant difference between µ-calpain of smoker men and non-smoker men. CPD showed negatively correlation with semen volume, concentration, motility and morphology of sperm. Conclusion: Sperm quality was negatively correlated with CPD and duration of smoking. However, there is no significant correlation between smoking and µ-calpain concentration. PMID:27385969

  17. RISK FACTORS FOR SLOW GAIT SPEED: A NESTED CASE-CONTROL SECONDARY ANALYSIS OF THE MEXICAN HEALTH AND AGING STUDY

    PubMed Central

    Pérez-Zepeda, M.U.; González-Chavero, J.G.; Salinas-Martinez, R.; Gutiérrez-Robledo, L.M.

    2016-01-01

    Background Physical performance tests play a major role in the geriatric assessment. In particular, gait speed has shown to be useful for predicting adverse outcomes. However, risk factors for slow gait speed (slowness) are not clearly described. Objectives To determine risk factors associated with slowness in Mexican older adults. Design A two-step process was adopted for exploring the antecedent risk factors of slow gait speed. First, the cut-off values for gait speed were determined in a representative sample of Mexican older adults. Then, antecedent risk factors of slow gait speed (defined using the identified cut-points) were explored in a nested, cohort case-control study. Setting, participants One representative sample of a cross-sectional survey for the first step and the Mexican Health and Aging Study (a cohort characterized by a 10-year follow-up). Measurements A 4-meter usual gait speed test was conducted. Lowest gender and height-stratified groups were considered as defining slow gait speed. Sociodemographic characteristics, comorbidities, psychological and health-care related variables were explored to find those associated with the subsequent development of slow gait speed. Unadjusted and adjusted logistic regression models were performed. Results In the final model, age, diabetes, hypertension, and history of fractures were associated with the development of slow gait speed. Conclusions Early identification of subjects at risk of developing slow gait speed may halt the path to disability due to the robust association of this physical performance test with functional decline. PMID:26889463

  18. Lack of Significant Effects of Chlamydia trachomatis Infection on Cervical Adenocarcinoma Risk: Nested Case-Control Study

    PubMed Central

    Smelov, Vitaly; Gheit, Tarik; Sundström, Karin; Ploner, Alexander; McKay-Chopin, Sandrine; Eklund, Carina; Tommasino, Massimo; Dillner, Joakim

    2016-01-01

    Background A role of Chlamydia trachomatis in HPV-induced cervical carcinogenesis has been reported for cervical cancer but studies on cervical adenocarcinoma are limited. Methods A total of 1,553 cervical smears taken up to 26 years before diagnosis in a large population-based nested case-control study of cervical adenocarcinoma (AC, 132 cases with matched controls), and adenocarcinoma in situ (AIS, 159 cases with matched controls) were tested for C. trachomatis and HPV DNA by a type-specific PCR bead-based multiplex genotyping (TS-MPG) assay. Results Only 1.7% of samples were positive for C. trachomatis, with no significant differences between AC/AIS cases and controls. HPV-positivity was detected in 49.3% of C. trachomatis-negative and 65.4% C. trachomatis-positive samples, respectively. Conclusions A large prospective study did not find any risk for cervical adenocarcinoma and/or AIS conferred by C. trachomatis infection. Impact C. trachomatis appears not to be involved in cervical adenocarcinomas. PMID:27227411

  19. Association between the OGG1 Ser326Cys Polymorphism and Cancer Risk: Evidence from 152 Case-Control Studies

    PubMed Central

    Zou, Hua; Li, Qing; Xia, Wei; Liu, Yong; Wei, Xi; Wang, Dong

    2016-01-01

    Although it has been suggested that the 8-oxoguanine DNA glycosylase (OGG1) gene Ser326Cys polymorphism may be a risk factor for cancer, the conclusions from previous studies are inconsistent. Thus, we conducted an updated meta-analysis to estimate the effect of OGG1 variant genotypes on cancer susceptibility. We searched the PubMed for all eligible studies published in English for the period ending September 2014. We found the association between OGG1 Ser326Cys polymorphism and cancer susceptibility based on 152 case-control studies in different genetic model comparisons (dominant model: OR = 1.053, P = 0.018; recessive model: OR = 1.108, P < 0.001; homozygote: OR = 1.135, P < 0.001; additive model: OR = 1.059, P < 0.001). However, the results from the subgroup analyses based on types of cancer, health population as controls or studies with relatively large sample size did not support the conclusion. Although the overall results of this meta-analysis showed a positive association between OGG1 variant genotypes and cancer susceptibility, the subgroup analyses by cancer type, sample size, and source of controls presented inconsistent results. Therefore, the current evidence from the meta-analysis did not support the hypothesis of OGG1 Ser326Cys polymorphism as a risk factor of cancer. PMID:27390603

  20. Multicenter Study of Brain Volume Abnormalities in Children and Adolescent-Onset Psychosis

    PubMed Central

    Reig, Santiago; Parellada, Mara; Castro-Fornieles, Josefina; Janssen, Joost; Moreno, Dolores; Baeza, Inmaculada; Bargalló, Nuria; González-Pinto, Ana; Graell, Montserrat; Ortuño, Felipe; Otero, Soraya; Arango, Celso; Desco, Manuel

    2011-01-01

    The goal of the study is to determine the extent of structural brain abnormalities in a multicenter sample of children and adolescents with a recent-onset first episode of psychosis (FEP), compared with a sample of healthy controls. Total brain and lobar volumes and those of gray matter (GM), white matter, and cerebrospinal fluid (CSF) were measured in 92 patients with a FEP and in 94 controls, matched for age, gender, and years of education. Male patients (n = 64) showed several significant differences when compared with controls (n = 61). GM volume in male patients was reduced in the whole brain and in frontal and parietal lobes compared with controls. Total CSF volume and frontal, temporal, and right parietal CSF volumes were also increased in male patients. Within patients, those with a further diagnosis of “schizophrenia” or “other psychosis” showed a pattern similar to the group of all patients relative to controls. However, bipolar patients showed fewer differences relative to controls. In female patients, only the schizophrenia group showed differences relative to controls, in frontal CSF. GM deficit in male patients with a first episode correlated with negative symptoms. Our study suggests that at least part of the GM deficit in children and adolescent-onset schizophrenia and in other psychosis occurs before onset of the first positive symptoms and that, contrary to what has been shown in children-onset schizophrenia, frontal GM deficits are probably present from the first appearance of positive symptoms in children and adolescents. PMID:20478821

  1. Thromboembolism after foot and ankle surgery. A multicenter study.

    PubMed

    Mizel, M S; Temple, H T; Michelson, J D; Alvarez, R G; Clanton, T O; Frey, C C; Gegenheimer, A P; Hurwitz, S R; Lutter, L D; Mankey, M G; Mann, R A; Miller, R A; Richardson, E G; Schon, L C; Thompson, F M; Yodlowski, M L

    1998-03-01

    Thromboembolic disease presents a potentially fatal complication to patients undergoing orthopaedic surgery. Although the incidence after hip and knee surgery has been studied and documented, its incidence after surgery of the foot and ankle is unknown. For this reason, a prospective multicenter study was undertaken to identify patients with clinically evident thromboembolic disease to evaluate potential risk factors. Two thousand seven hundred thirty-three patients were evaluated for preoperative risk factors and postoperative thromboembolic events. There were six clinically significant thromboembolic events, including four nonfatal pulmonary emboli, after foot and ankle surgery. The incidence of deep vein thrombosis was six of 2733 (0.22%) and that of nonfatal pulmonary emboli was four of 2733 (0.15%). Factors found to correlate with an increased incidence of deep vein thrombosis were nonweightbearing status and immobilization after surgery. On the basis of these results, routine prophylaxis for thromboembolic disease after foot and ankle surgery probably is not warranted. PMID:9553551

  2. Forming a Research Question from a Multi-Center Database

    PubMed Central

    Likosky, Donald S.

    2009-01-01

    Abstract: It is not uncommon for individuals to ask biostatisiticians and epidemiologists to assist them with a research project. Often the request is in the shape of statistical analyses. However, most of these requests are nothing more than missed opportunities. This manuscript focuses on the reasons underlying such a statement. Most individuals might say that the most important aspect of a study is its conclusion. Many who would disagree with this sentiment and would feel that the most important aspect of a study rather is the question it intends to address. If this question is not articulated sufficiently, any additional information stemming from the study will most likely be irrelevant. Herein, some principles for formulating (successfully) a question from a multi-center database will be described. PMID:19361039

  3. Renal cell carcinoma in South Korea: a multicenter study.

    PubMed

    Kim, Haeryoung; Cho, Nam Hoon; Kim, Dong-Sug; Kwon, Young-Mi; Kim, Eun Kyung; Rha, Seo Hee; Park, Yong Wook; Shim, Jung Weon; Lee, Sang Sook; Lee, Shi Nae; Lee, Juhie; Lee, Jin Sook; Lee, Tae-Jin; Jung, Soo Jin; Jung, Soon-Hee; Chung, Jin Haeng; Cho, Hyun Yee; Joo, Hee Jae; Choi, Yeong-Jin; Choi, Chan; Han, Woon Sup; Hur, Bang; Ro, Jae Y

    2004-12-01

    The incidence of renal cell carcinoma (RCC) in South Korea is steadily becoming similar to that in Western countries. This study summarizes the results of a 3-year multicenter survey of RCC in South Korea, conducted by the Korean Genitourinary Pathology Study Group. A total of 795 cases of RCC were collected from 20 institutes between 1995 and 1997, including 686 clear cell RCCs (86.3%), 58 papillary RCCS (7.30%), 49 chromphobe RCCs (6.16%), and 2 collecting duct RCCs (0.25%). At least 5 years of follow-up was available for 627 clear cell, 54 papillary, and 49 chromophobe RCCs. All subtypes presented most frequently with stage T3aN0M0 at the time of operation, and papillary RCCs demonstrated more frequent lymph node metastasis. Overall survival was not significantly related to the histological subtype (clear cell vs papillary, P = 0.8651; clear cell vs chromophobe, P = 0.0584; papillary vs chromophobe, P = 0.0743). For clear cell RCCs, statistically significant associations were found between overall survival and sex (P = 0.0153), multiplicity (P = 0.0461), necrosis (P = 0.0191), age, sarcomatoid change, TNM stage, nuclear grade, and modality of treatment (all P <0.0001). Overall survival was significantly associated with tumor size (P = 0.0307), nuclear grade (P = 0.0235), multiplicity, sarcomatoid change, and TNM stage (all P <0.0001) for papillary RCCs and with the presence of sarcomatoid change (P = 0.0281), nuclear grade (P = 0.0015), treatment modality (P = 0.0328), and TNM stage (P <0.0001) for chromophobe RCCs. Age (P = 0.0125), nodal stage (P = 0.0010), and treatment modality (P = 0.0001) were significant independent prognostic indicators for clear cell RCC on multivariate analysis. This is the first multicenter study of RCC in South Korea, demonstrating the general patterns and prognostic factors of Korean RCCs. PMID:15619217

  4. Descriptive Epidemiology of the Multicenter ACL Revision Study (MARS) Cohort

    PubMed Central

    2013-01-01

    Background Revision anterior cruciate ligament (ACL) reconstruction has worse outcomes than primary reconstructions. Predictors for these worse outcomes are not known. The Multicenter ACL Revision Study (MARS) Group was developed to perform a multisurgeon, multicenter prospective longitudinal study to obtain sufficient subjects to allow multivariable analysis to determine predictors of clinical outcome. Purpose To describe the formation of MARS and provide descriptive analysis of patient demographics and clinical features for the initial 460 enrolled patients to date in this prospective cohort. Study Design Cross-sectional study; Level of evidence, 2. Methods After training and institutional review board approval, surgeons began enrolling patients undergoing revision ACL reconstruction, recording patient demographics, previous ACL reconstruction methods, intra-articular injuries, and current revision techniques. Enrolled subjects completed a questionnaire consisting of validated patient-based outcome measures. Results As of April 1, 2009, 87 surgeons have enrolled a total of 460 patients (57% men; median age, 26 years). For 89%, the reconstruction was the first revision. Mode of failure as deemed by the revising surgeon was traumatic (32%), technical (24%), biologic (7%), combination (37%), infection (<1%), and no response (<1%). Previous graft present at the time of injury was 70% autograft, 27% allograft, 2% combination, and 1% unknown. Sixty-two percent were more than 2 years removed from their last reconstruction. Graft choice for revision ACL reconstruction was 45% autograft, 54% allograft, and more than 1% both allograft and autograft. Meniscus and/or chondral damage was found in 90% of patients. Conclusion The MARS Group has been able to quickly accumulate the largest revision ACL reconstruction cohort reported to date. Traumatic reinjury is deemed by surgeons to be the most common single mode of failure, but a combination of factors represents the most

  5. Oral Lymphoma Prevalence in Iranian Population: A Multicenter Retrospective Study

    PubMed Central

    Akbari, Mohammad Esmaeil; Bastani, Zahra; Mokhtari, Sepideh; Atarbashi Moghadam, Saede

    2015-01-01

    Background: Oral lymphoma is the second most common malignancy of the head and neck region after malignant epithelial tumors. Objectives: Considering the lack of a multicenter study on the frequency of oral lymphoma in Iran, this study aimed to assess the relative frequency of oral lymphomas in Iran during a 6-year period. Materials and Methods: This multicenter, retrospective, cross-sectional study was conducted in two phases. In the first phase, cases of oral lymphoma registered in the cancer research center (CRC) of Shahid Beheshti university of medical sciences were extracted. The patient records and pathology reports of these patients were retrieved from the archives and age, sex and microscopic type site of the lesions were evaluated. Results: Oral lymphoma accounts for 1% of head and neck malignancies and 8% of all lymphomas. From 2003 to 2008, a total of 437 new cases of oral lymphomas had been registered in the CRC. Diffuse large B-cell lymphoma was found to be the most common form of oral lymphoma in the 6-year period with 240 (54.9%) registered cases. The majority of detected cases were in the 6th and 7th decades of life with a male to female ratio of 1:84. Tonsils were the most common site of occurrence of lymphoma in the oral cavity (77.8%). Conclusions: The age of onset, site of involvement, sex of patients, and histopathological subtype of oral lymphomas in the Iranian population were found to be similar to those of most other countries. PMID:26855724

  6. Multi-Center Electronic Structure Calculations for Plasma Equation of State

    SciTech Connect

    Wilson, B G; Johnson, D D; Alam, A

    2010-12-14

    We report on an approach for computing electronic structure utilizing solid-state multi-center scattering techniques, but generalized to finite temperatures to model plasmas. This approach has the advantage of handling mixtures at a fundamental level without the imposition of ad hoc continuum lowering models, and incorporates bonding and charge exchange, as well as multi-center effects in the calculation of the continuum density of states.

  7. Robust Automated Detection of Microstructural White Matter Degeneration in Alzheimer’s Disease Using Machine Learning Classification of Multicenter DTI Data

    PubMed Central

    Dyrba, Martin; Ewers, Michael; Wegrzyn, Martin; Kilimann, Ingo; Plant, Claudia; Oswald, Annahita; Meindl, Thomas; Pievani, Michela; Bokde, Arun L. W.; Fellgiebel, Andreas; Filippi, Massimo; Hampel, Harald; Klöppel, Stefan; Hauenstein, Karlheinz; Kirste, Thomas; Teipel, Stefan J.

    2013-01-01

    Diffusion tensor imaging (DTI) based assessment of white matter fiber tract integrity can support the diagnosis of Alzheimer’s disease (AD). The use of DTI as a biomarker, however, depends on its applicability in a multicenter setting accounting for effects of different MRI scanners. We applied multivariate machine learning (ML) to a large multicenter sample from the recently created framework of the European DTI study on Dementia (EDSD). We hypothesized that ML approaches may amend effects of multicenter acquisition. We included a sample of 137 patients with clinically probable AD (MMSE 20.6±5.3) and 143 healthy elderly controls, scanned in nine different scanners. For diagnostic classification we used the DTI indices fractional anisotropy (FA) and mean diffusivity (MD) and, for comparison, gray matter and white matter density maps from anatomical MRI. Data were classified using a Support Vector Machine (SVM) and a Naïve Bayes (NB) classifier. We used two cross-validation approaches, (i) test and training samples randomly drawn from the entire data set (pooled cross-validation) and (ii) data from each scanner as test set, and the data from the remaining scanners as training set (scanner-specific cross-validation). In the pooled cross-validation, SVM achieved an accuracy of 80% for FA and 83% for MD. Accuracies for NB were significantly lower, ranging between 68% and 75%. Removing variance components arising from scanners using principal component analysis did not significantly change the classification results for both classifiers. For the scanner-specific cross-validation, the classification accuracy was reduced for both SVM and NB. After mean correction, classification accuracy reached a level comparable to the results obtained from the pooled cross-validation. Our findings support the notion that machine learning classification allows robust classification of DTI data sets arising from multiple scanners, even if a new data set comes from a scanner that was

  8. Evaluating and comparing biomarkers with respect to the area under the receiver operating characteristics curve in two-phase case-control studies.

    PubMed

    Huang, Ying

    2016-07-01

    Two-phase sampling design, where biomarkers are subsampled from a phase-one cohort sample representative of the target population, has become the gold standard in biomarker evaluation. Many two-phase case-control studies involve biased sampling of cases and/or controls in the second phase. For example, controls are often frequency-matched to cases with respect to other covariates. Ignoring biased sampling of cases and/or controls can lead to biased inference regarding biomarkers' classification accuracy. Considering the problems of estimating and comparing the area under the receiver operating characteristics curve (AUC) for a binary disease outcome, the impact of biased sampling of cases and/or controls on inference and the strategy to efficiently account for the sampling scheme have not been well studied. In this project, we investigate the inverse-probability-weighted method to adjust for biased sampling in estimating and comparing AUC. Asymptotic properties of the estimator and its inference procedure are developed for both Bernoulli sampling and finite-population stratified sampling. In simulation studies, the weighted estimators provide valid inference for estimation and hypothesis testing, while the standard empirical estimators can generate invalid inference. We demonstrate the use of the analytical variance formula for optimizing sampling schemes in biomarker study design and the application of the proposed AUC estimators to examples in HIV vaccine research and prostate cancer research. PMID:26883772

  9. 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. PMID:24861979

  10. Case-control geographic clustering for residential histories accounting for risk factors and covariates

    PubMed Central

    2006-01-01

    Background Methods for analyzing space-time variation in risk in case-control studies typically ignore residential mobility. We develop an approach for analyzing case-control data for mobile individuals and apply it to study bladder cancer in 11 counties in southeastern Michigan. At this time data collection is incomplete and no inferences should be drawn – we analyze these data to demonstrate the novel methods. Global, local and focused clustering of residential histories for 219 cases and 437 controls is quantified using time-dependent nearest neighbor relationships. Business address histories for 268 industries that release known or suspected bladder cancer carcinogens are analyzed. A logistic model accounting for smoking, gender, age, race and education specifies the probability of being a case, and is incorporated into the cluster randomization procedures. Sensitivity of clustering to definition of the proximity metric is assessed for 1 to 75 k nearest neighbors. Results Global clustering is partly explained by the covariates but remains statistically significant at 12 of the 14 levels of k considered. After accounting for the covariates 26 Local clusters are found in Lapeer, Ingham, Oakland and Jackson counties, with the clusters in Ingham and Oakland counties appearing in 1950 and persisting to the present. Statistically significant focused clusters are found about the business address histories of 22 industries located in Oakland (19 clusters), Ingham (2) and Jackson (1) counties. Clusters in central and southeastern Oakland County appear in the 1930's and persist to the present day. Conclusion These methods provide a systematic approach for evaluating a series of increasingly realistic alternative hypotheses regarding the sources of excess risk. So long as selection of cases and controls is population-based and not geographically biased, these tools can provide insights into geographic risk factors that were not specifically assessed in the case-control

  11. A multicenter, cross-platform clinical validation study of cancer cytogenomic arrays.

    PubMed

    Li, Marilyn M; Monzon, Federico A; Biegel, Jaclyn A; Jobanputra, Vaidehi; Laffin, Jennifer J; Levy, Brynn; Leon, Annette; Miron, Patricia; Rossi, Michael R; Toruner, Gokce; Alvarez, Karla; Doho, Gregory; Dougherty, Margaret J; Hu, Xiaofeng; Kash, Shera; Streck, Deanna; Znoyko, Iya; Hagenkord, Jill M; Wolff, Daynna J

    2015-11-01

    Cytogenomic microarray analysis (CMA) offers high resolution, genome-wide copy number information and is widely used in clinical laboratories for diagnosis of constitutional abnormalities. The Cancer Genomics Consortium (CGC) conducted a multiplatform, multicenter clinical validation project to compare the reliability and inter- and intralaboratory reproducibility of this technology for clinical oncology applications. Four specimen types were processed on three different microarray platforms-from Affymetrix, Agilent, and Illumina. Each microarray platform was employed at two independent test sites. The results were compared in a blinded manner with current standard methods, including karyotype, FISH, or morphology. Twenty-nine chronic lymphocytic leukemia blood, 34 myelodysplastic syndrome bone marrow, and 30 fresh frozen renal epithelial tumor samples were assessed by all six laboratories. Thirty formalin fixed paraffin embedded renal tumor samples were analyzed at the Affymetrix and Agilent test sites only. All study samples were initial diagnostic samples. Array data were analyzed at each participating site and were submitted to caArray for central analysis. Laboratory interpretive results were submitted to the central analysis team for comparison with the standard-of-care assays and for calculation of intraplatform reproducibility and cross-platform concordance. The results demonstrated that the three microarray platforms 1) detect clinically actionable genomic changes in cancer compatible to standard-of-care methods; 2) further define cytogenetic aberrations; 3) identify submicroscopic alterations and loss of heterozygosity (LOH); and 4) yield consistent results within and between laboratories. Based on this study, the CGC concludes that CMA is a sensitive and reliable technique for copy number and LOH assessment that may be used for clinical oncology genomic analysis. PMID:26454669

  12. Transmission Assessment Surveys (TAS) to Define Endpoints for Lymphatic Filariasis Mass Drug Administration: A Multicenter Evaluation

    PubMed Central

    Chu, Brian K.; Deming, Michael; Biritwum, Nana-Kwadwo; Bougma, Windtaré R.; Dorkenoo, Améyo M.; El-Setouhy, Maged; Fischer, Peter U.; Gass, Katherine; Gonzalez de Peña, Manuel; Mercado-Hernandez, Leda; Kyelem, Dominique; Lammie, Patrick J.; Flueckiger, Rebecca M.; Mwingira, Upendo J.; Noordin, Rahmah; Offei Owusu, Irene; Ottesen, Eric A.; Pavluck, Alexandre; Pilotte, Nils; Rao, Ramakrishna U.; Samarasekera, Dilhani; Schmaedick, Mark A.; Settinayake, Sunil; Simonsen, Paul E.; Supali, Taniawati; Taleo, Fasihah; Torres, Melissa; Weil, Gary J.; Won, Kimberly Y.

    2013-01-01

    Background Lymphatic filariasis (LF) is targeted for global elimination through treatment of entire at-risk populations with repeated annual mass drug administration (MDA). Essential for program success is defining and confirming the appropriate endpoint for MDA when transmission is presumed to have reached a level low enough that it cannot be sustained even in the absence of drug intervention. Guidelines advanced by WHO call for a transmission assessment survey (TAS) to determine if MDA can be stopped within an LF evaluation unit (EU) after at least five effective rounds of annual treatment. To test the value and practicality of these guidelines, a multicenter operational research trial was undertaken in 11 countries covering various geographic and epidemiological settings. Methodology The TAS was conducted twice in each EU with TAS-1 and TAS-2 approximately 24 months apart. Lot quality assurance sampling (LQAS) formed the basis of the TAS survey design but specific EU characteristics defined the survey site (school or community), eligible population (6–7 year olds or 1st–2nd graders), survey type (systematic or cluster-sampling), target sample size, and critical cutoff (a statistically powered threshold below which transmission is expected to be no longer sustainable). The primary diagnostic tools were the immunochromatographic (ICT) test for W. bancrofti EUs and the BmR1 test (Brugia Rapid or PanLF) for Brugia spp. EUs. Principal Findings/Conclusions In 10 of 11 EUs, the number of TAS-1 positive cases was below the critical cutoff, indicating that MDA could be stopped. The same results were found in the follow-up TAS-2, therefore, confirming the previous decision outcome. Sample sizes were highly sex and age-representative and closely matched the target value after factoring in estimates of non-participation. The TAS was determined to be a practical and effective evaluation tool for stopping MDA although its validity for longer-term post-MDA surveillance

  13. 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. PMID:16494130

  14. Risk factors for neuroleptic malignant syndrome. A case-control study.

    PubMed

    Keck, P E; Pope, H G; Cohen, B M; McElroy, S L; Nierenberg, A A

    1989-10-01

    A number of risk factors have been proposed for the development of neuroleptic malignant syndrome, but these have not been subjected to controlled study. To address this problem, we performed a case-control study comparing 18 patients with neuroleptic malignant syndrome and 36 matched neuroleptic-treated control patients with no known history of the syndrome to identify potential risk factors. Patients with neuroleptic malignant syndrome displayed significantly greater psychomotor agitation, received significantly higher doses of neuroleptics at greater rates of dosage increase, and received a greater number of intramuscular injections than controls. PMID:2572206

  15. Occupational risk factors and Alzheimer's disease: a case-control study

    SciTech Connect

    Shalat, S.L.; Seltzer, B.; Baker, E.L. Jr.

    1988-12-01

    A case-control study was conducted to assess occupational exposure to organic solvents and lead as risk factors for Alzheimer's disease. All case subjects were diagnosed at a Veterans Administration Hospital in Bedford, Massachusetts. Control subjects were selected from Massachusetts voter registration lists and matched by sex, year of birth, and town of residence. Information on occupational history was assessed by mailed questionnaire sent to the spouse or next of kin of the study subject. A total of 98 case and 162 control subjects were included in the matched analysis. No apparent association of increased risk of Alzheimer's disease was observed for ever having occupational exposure to organic solvents or lead.

  16. Suicide by people in a community justice pathway: population-based nested case-control study.

    PubMed

    King, Carlene; Senior, Jane; Webb, Roger T; Millar, Tim; Piper, Mary; Pearsall, Alison; Humber, Naomi; Appleby, Louis; Shaw, Jenny

    2015-08-01

    The elevated risk of suicide in prison and after release is a well-recognised and serious problem. Despite this, evidence concerning community-based offenders' suicide risk is sparse. We conducted a population-based nested case-control study of all people in a community justice pathway in England and Wales. Our data show 13% of general population suicides were in community justice pathways before death. Suicide risks were highest among individuals receiving police cautions, and those having recent, or impending prosecution for sexual offences. Findings have implications for the training and practice of clinicians identifying and assessing suicidality, and offering support to those at elevated risk. PMID:26159602

  17. Pancreas cancer, tobacco smoking and consumption of alcoholic beverages: a case-control study.

    PubMed

    Partanen, T J; Vainio, H U; Ojajärvi, I A; Kauppinen, T P

    1997-06-01

    A population-based case-control study investigated pancreas cancer in relation to consumption of alcoholic beverages, tobacco smoking and pancreatitis, utilizing historical proxy data for 662 decedent Finnish pancreas cancer cases and 1770 cancer controls. Tobacco smoking increased the risk, with an attributable case fraction of 0.27. The data are consistent with a joint effect of early and late stage carcinogens in tobacco smoke. Consumption of distilled beverages did not increase risk, but heavy drinking of wine or beer did. History of pancreatitis was a strong risk factor. PMID:9177454

  18. Primary postpartum haemorrhage in an Australian tertiary hospital: a case-control study.

    PubMed

    Henry, Amanda; Birch, Mary-Rose; Sullivan, Elizabeth A; Katz, Sue; Wang, Yueping Alex

    2005-06-01

    The present study aimed to determine the incidence of primary postpartum haemorrhage (PPH) after vaginal birth at an Australian tertiary hospital, and to investigate risk factors for primary PPH at this hospital. A case-control study of women delivering vaginally at a tertiary hospital from February to June 2003 was performed. Demographic, antenatal, intrapartum, treatment and outcome data were abstracted from patient records. The study population comprised 125 cases and 125 controls, with a primary PPH rate of 12.1 per 100 vaginal births. Risk factors on multivariate analysis were past history of PPH, second stage labour > 60 min, forceps delivery, and incomplete placenta/ragged membranes. PMID:15904450

  19. Case-control study: soft-tissue sarcomas and exposure to phenoxyacetic acids or chlorophenols.

    PubMed Central

    Hardell, L.; Sandström, A.

    1979-01-01

    In 1977 a number of patients with soft-tissue sarcomas and previous exposure to phenoxyacetic acids were described. Following from these observations a matched case-control study was made. Exposure to chlorophenols was also included in this study. The results showed that exposure to phenoxyacetic acids or chlorophenols gave an approximately 6-fold increase in the risk for this type of tumour. It was not possible to determine, however, whether the carcinogenic effect was exerted by these compounds or by impurities such as chlorinated dibenzodioxins and dibenzofurans that in almost all cases were part of the commercial preparations. PMID:444410

  20. Diesel exhaust exposure and lung cancer: a case-control study

    SciTech Connect

    Hall, N.E.L.; Wynder, E.L.

    1984-06-01

    The presence of polyaromatic hydrocarbons in the particulate phase of diesel engine exhaust has raised questions concerning potential carcinogenicity of diesel exhaust exposure. A case-control study was conducted of 502 male lung cancer cases and 502 controls without tobacco-related diseases to investigate the association of occupational diesel exhaust exposure and lung cancer. Diesel exhaust exposure was appraised by job title. The results show no association between diesel exhaust exposure and risk of lung cancer. They do, however, show the strong association between smoking and lung cancer and as such highlight the importance of smoking information in studies of occupational effect on lung cancer risk.

  1. 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. PMID:26020580

  2. [Recurrent myocardial infarctions: specific changes in biomarkers and in myocardial remodeling (case-control study)].

    PubMed

    Volkova, E G; Malykhina, O P; Levashov, S Iu

    2007-01-01

    Basing on a case-control study (n=81) with the use of standard methods of myocardial infarction verification, examination of hemogram, troponin T, C-reactive protein, echocardiography data it was established that markers of myocardial infarction (troponin T level) and inflammation (C reactive protein level, lymphopenia) during recurrent infarctions are less pronounced than during first infarctions. Remodeling in recurrent infarctions had the following specific characteristics: increase of left ventricular end diastolic dimension, myocardial mass index, diastolic dysfunction and stroke volume with unchanged ejection fraction. PMID:18260891

  3. The efficacy of Japanese encephalitis vaccine in Henan, China: a case-control study.

    PubMed

    Luo, D; Yin, H; Xili, L; Song, J; Wang, Z

    1994-12-01

    A population based case-control study to evaluate Japanese encephalitis (JE) vaccine efficacy was carried out in Gusi County, Henan Province, China from June to September in 1991. This study showed that the JE vaccine had a strong protective effect. The estimate of the vaccine efficacy was 78% (95% CI = 16-94%). An unimmunized child was at 4.54 times greater risk of developing JE than were fully immunized children during the study period. The present study may have underestimated the vaccine efficacy due to evaluation based on routine vaccination which might have been affected by vaccination management and the local cold chain system. PMID:7667706

  4. Impact of traumatic dental injury on the quality of life of young children: a case-control study.

    PubMed

    Vieira-Andrade, Raquel Gonçalves; Siqueira, Maria Betânia Lins; Gomes, Genara Brum; D'Avila, Sérgio; Pordeus, Isabela Almeida; Paiva, Saul Martins; Granville-Garcia, Ana Flávia

    2015-10-01

    There are no longitudinal studies that assess the impact of traumatic dental injury (TDI) on the oral health-related quality of life (OHRQoL) of preschool children. To investigate the impact of TDI on OHRQoL among preschool children, a population-based case-control study was carried out with a representative sample of 335 children, 3-5 years of age, enrolled at public and private preschools in the city of Campina Grande, Brazil. The case group and the control group were matched for age, gender, type of preschool and monthly household income at a ratio of 1:4 (67 cases and 286 controls). Impact on the OHRQoL of children was assessed through administration of the Early Childhood Oral Health Impact Scale (ECOHIS). The occurrence of TDI was determined through clinical examinations performed by three calibrated dentists. Data analysis involved descriptive statistics, McNemar's test, the chi-square test with linear trend and conditional logistic regression analysis [P≤0.05; 95% confidence interval (95% CI)]. The most frequent responses were 'felt pain' (19.4%) and 'difficulty eating' (16.4%). The prevalence of TDI was 37.3% in the case group and 33.9% in the control group. No statistically significant differences were found between case and control groups regarding the presence of TDI (odds ratio=1.16; 95% CI: 0.66-2.02). TDI had no impact on the quality of life of preschool children. PMID:26311004

  5. Tobacco, alcohol, asbestos, and nickel in the etiology of cancer of the larynx: a case-control study

    SciTech Connect

    Burch, J.D.; Howe, G.R.; Miller, A.B.; Semenciw, R.

    1981-12-01

    A case-control study of laryngeal cancer was conducted in southern Ontario between 1977 and 1979 with 204 subjects with newly diagnosed cancer and 204 controls, individually matched by sex, age, and residence. Tobacco products and alcohol showed strong associations with cancer of the larynx for males, with relative risks (RR) for users of cigarettes, cigars or cigarillos, pipes, and alcohol of 6.1, 2.9, 1.6, and 5.2, respectively. The population attributable risk percent for males using tobacco products and alcohol together was estimated to be 94%. Cigarette smoking was also an important risk factor for females, although the small number of female pairs (20) precluded any meaningful detailed analysis of other possible risk factors. The RR for males for exposure to asbestos after the effects of cigarette smoking were controlled was 2.3, and the effects seemed restricted to cigarette smokers. The findings on asbestos were based on small numbers of cases and controls exposed and consequently were subject to large sampling errors. The estimate was consistent, however, with that from other studies and supported a causal role for asbestos exposure and cancer of the larynx. The RR for males for exposure to nickel was 0.9.

  6. Emotional processing and its relationship to chronic low back pain: results from a case-control study.

    PubMed

    Esteves, Jorge E; Wheatley, Laura; Mayall, Clare; Abbey, Hilary

    2013-12-01

    Chronic low back pain (CLBP) is a common, yet challenging condition for both patients and clinicians. Several studies have demonstrated a strong association between CLBP and psychological factors such as anxiety, fear-avoidance, self-efficacy, catastrophizing and depression. These factors are closely linked with emotional states; however, it is unknown whether CLBP patients process their emotions differently from asymptomatic individuals. The aim of this case-control study was to investigate the relationship between CLBP and emotional processing. A sample of 110 participants comprising of 55 patients with chronic back pain and 55 individuals without a history of CLBP were assessed using the Emotional Processing Scale (EPS-25). The EPS-25 generates an overall score, and also scores pertaining to five individual emotional processing factors--avoidance, suppression, unregulated emotion, impoverished emotional experience and signs of unprocessed emotion. Chronic back pain patients scored significantly higher in the overall EPS-25 score (p < 0.001) with an effect size of 0.33. In addition, there were significant differences in four factors--impoverished emotional experience, unregulated emotion, unprocessed emotion, and suppression, with effect sizes ranging from 0.20 to 0.44. The results suggest that dysfunctional emotional processing, particularly with regard to the suppression of emotions, is associated with CLBP. Clinicians should critically consider the role of emotional processing in their patients' evaluation and management. Future research using a prospective cohort should assess the role of emotional processing as a predictor in the development of chronic back pain. PMID:23756033

  7. Is prenatal childbirth preparation effective in decreasing adverse maternal and neonatal response to labor? A nested case-control study.

    PubMed

    Kim, Hyun Hee; Nava-Ocampo, Alejandro A; Kim, Sun Kyung; Kim, Seo Hui; Kim, Yun Ju; Han, Jung Yeol; Ahn, Hyun Kyong; Ryu, Hyun Mee; Yang, Jae Hyug; Kim, Moon Young

    2008-04-01

    Sophrology, based on a combination of Western relaxation therapy and Eastern yoga and meditation might decrease maternal stress during labor. This study aimed to evaluate whether prenatal sophrologic childbirth preparation may decrease maternal and neonatal adverse response associated with delivery. In a nested case-control study, 69 nulliparous, singleton pregnant women who underwent an educational course of sophrologic childbirth preparation were compared to 69 nulliparous, singleton, age- and gestational age-matched pregnant women who did not receive any childbirth preparation. All babies were vaginally delivered. Groups were not different (P > 0.05) in the number of neonates born with meconium-stained amniotic fluid as well as in the number of babies with Apgar score < or = 7 at 1 and 5 minutes after birth. Duration of labor was not different between groups. The number of women requiring oxytocin and delivering babies with low pH blood levels tended to be lower in the group undergoing sophrologic childbirth preparation, i.e. 58.0% vs 72.5% (P = 0.07) and 1.4% vs 10.9% (P = 0.06), respectively. In conclusion, we were unable to confirm that prenatal sophrologic childbirth preparation has a definitive role in decreasing adverse maternal and fetal response to pain or in shortening labor. Prospective cohort studies with a larger sample size or randomized trials may help to clarify this gap. PMID:18551817

  8. Environmental Risk Factors and Amyotrophic Lateral Sclerosis (ALS): A Case-Control Study of ALS in Michigan

    PubMed Central

    Yu, Yu; Su, Feng-Chiao; Callaghan, Brian C.; Goutman, Stephen A.; Batterman, Stuart A.; Feldman, Eva L.

    2014-01-01

    An interim report of a case-control study was conducted to explore the role of environmental factors in the development of amyotrophic lateral sclerosis (ALS). Sixty-six cases and 66 age- and gender-matched controls were recruited. Detailed information regarding residence history, occupational history, smoking, physical activity, and other factors was obtained using questionnaires. The association of ALS with potential risk factors, including smoking, physical activity and chemical exposure, was investigated using conditional logistic regression models. As compared to controls, a greater number of our randomly selected ALS patients reported exposure to fertilizers to treat private yards and gardens and occupational exposure to pesticides in the last 30 years than our randomly selected control cases. Smoking, occupational exposures to metals, dust/fibers/fumes/gas and radiation, and physical activity were not associated with ALS when comparing the randomly selected ALS patients to the control subjects. To further explore and confirm results, exposures over several time frames, including 0–10 and 10–30 years earlier, were considered, and analyses were stratified by age and gender. Pesticide and fertilizer exposure were both significantly associated with ALS in the randomly selected ALS patients. While study results need to be interpreted cautiously given the small sample size and the lack of direct exposure measures, these results suggest that environmental and particularly residential exposure factors warrant close attention in studies examining risk factors of ALS. PMID:24979055

  9. High Seroprevalence of Bordetella pertussis in Patients with Chronic Obstructive Pulmonary Disease: A Case-Control Study

    PubMed Central

    Nadi, Ebrahim; Hajilooi, Mehrdad; Seif-Rabiei, Mohammad-Ali; Samaei, Atefeh

    2015-01-01

    Background: Bordetella pertussis has been suggested to take part in the acute exacerbation of chronic obstructive pulmonary disease (COPD). The aim of this study was to investigate the association between B. pertussis and COPD. Materials and Methods: In this case-control study, 90 patients with COPD and 90 age- and sex- matched control subjects were included. Serum samples were tested for anti-B. pertussis IgG and IgA by ELISA. A physician completed a questionnaire including demographic characteristics, habitual history and spirometric findings for each patient. Results: Of 90 patients with chronic obstructive pulmonary disease, 66 (51%) had mild, 31 (34.4%) had moderate, and 13 (14.4%) had severe disease. There was no significant association between B. pertussis IgA seropositivity and COPD. Serum levels of anti- B. pertussis IgG were significantly higher in patients with COPD than in the control subjects (P < 0.001). No association was observed between B. pertussis infection and severity of COPD. Conclusion: The results suggest that there is an association between B. pertussis infection and COPD. Further studies should be planned to investigate the potential pathogenic mechanisms underlying these associations. PMID:26858762

  10. Bayesian analysis on meta-analysis of case-control studies accounting for within-study correlation.

    PubMed

    Chen, Yong; Chu, Haitao; Luo, Sheng; Nie, Lei; Chen, Sining

    2015-12-01

    In retrospective studies, odds ratio is often used as the measure of association. Under independent beta prior assumption, the exact posterior distribution of odds ratio given a single 2 × 2 table has been derived in the literature. However, independence between risks within the same study may be an oversimplified assumption because cases and controls in the same study are likely to share some common factors and thus to be correlated. Furthermore, in a meta-analysis of case-control studies, investigators usually have multiple 2 × 2 tables. In this article, we first extend the published results on a single 2 × 2 table to allow within study prior correlation while retaining the advantage of closed-form posterior formula, and then extend the results to multiple 2 × 2 tables and regression setting. The hyperparameters, including within study correlation, are estimated via an empirical Bayes approach. The overall odds ratio and the exact posterior distribution of the study-specific odds ratio are inferred based on the estimated hyperparameters. We conduct simulation studies to verify our exact posterior distribution formulas and investigate the finite sample properties of the inference for the overall odds ratio. The results are illustrated through a twin study for genetic heritability and a meta-analysis for the association between the N-acetyltransferase 2 (NAT2) acetylation status and colorectal cancer. PMID:22143403

  11. Association of Hepatitis C Virus Infection with Type II Diabetes in Ethiopia: A Hospital-Based Case-Control Study

    PubMed Central

    Ali, Solomon; Abera, Solomon; Mihret, Adane; Abebe, Tamrat

    2012-01-01

    Background. Chronic hepatitis C virus (HCV) has become the global “epidemic” with an estimated 123 million people currently infected worldwide. As the same time diabetes is also rapidly emerging as a global health care problem that threatens to reach pandemic levels by 2030. Objective. To investigate the magnitude of HCV infection in type II diabetes as compared to controls. Methodology. A case control study design was conducted at Jimma University Specialized Hospital from May to June 2010. A total of 604 study subjects were included in this study. Sociodemographic and risk factor data were collected by questionnaire. From serum sample, HCVAb screening was done by rapid antibody screening test. Liver functioning tests and total cholesterol tests were done by Dr. Lange LP 800 spectrophotometer. Results. The prevalence of HCV in type II diabetes and nondiabetic controls was 9.9% and 3.3%, respectively. In multivariate analysis, HCV seropositives have high risk of developing diabetes as compared with seronegatives (AOR = 2.997, 95% CI: (1.08, 8.315)). Conclusion. In this study, we found a positive association between past HCV infection and type II diabetes. As we did not perform HCV RNA test, we could not assess the association with HCV viremia. PMID:23049551

  12. A case-control study of motor neurone disease: its relation to heritability, and occupational exposures, particularly to solvents.

    PubMed Central

    Gunnarsson, L G; Bodin, L; Söderfeldt, B; Axelson, O

    1992-01-01

    Motor neurone disease (MND) was studied in relation to various determinants in a case-control study covering nine counties in southern Sweden. A questionnaire about occupational exposures, medical history, lifestyle factors etc was given to all cases in the age range 45-79 and to a random sample of 500 population controls in the same age range. The questionnaires were answered by 92 cases and 372 controls, a response rate of 85% and 75% respectively. Among men high Mantel-Haenszel odds ratios (MHORs) were obtained for electricity work (MHOR = 6.7, 95% confidence interval (95% CI) 1.0-32.1), welding (MHOR = 3.7, 95% CI 1.1-13.0), and impregnating agents (MHOR = 3.5, 95% CI 0.9-13.1). Heritability with regard to a neurodegenerative disease or thyroid disease seemed to predispose to a risk of developing MND (OR = 2.1, 95% CI 1.0-4.3). The highest OR was found for the combination of such heritability, exposure to solvents, and male sex (OR = 15.6, 95% CI 2.8-87.0), a combination that occurred for seven cases and three controls. Hereditary factors and external exposures had a different distribution among cases with the spinal type of MND than among cases with involvement of the pyramidal tract or bulbar paresis also. PMID:1463680

  13. Signs, symptoms, parafunctions and associated factors of parent-reported sleep bruxism in children: a case-control study.

    PubMed

    Serra-Negra, Júnia Maria; Paiva, Saul Martins; Auad, Sheyla Márcia; Ramos-Jorge, Maria Letícia; Pordeus, Isabela Almeida

    2012-01-01

    Bruxism is the non-functional clenching or grinding of the teeth that may occur during sleep or less commonly in daytime. The aim of this study was to investigate the association between clinical signs and symptoms, parafunctions and associated factors of sleep bruxism in children. A population-based case-control study was carried out involving 120 children, 8 years of age, with sleep bruxism and 240 children without sleep bruxism. The sample was randomly selected from public and private schools in the city of Belo Horizonte, MG, Brazil. Groups were matched by gender and social class. The Social Vulnerability Index (SVI) drawn up by the city of Belo Horizonte was employed for social classification. Data collection instruments included clinical forms and pre-tested questionnaires. The diagnosis of sleep bruxism was supported by the American Association of Sleep Medicine (AASM) criteria. The McNemar test, binary and multivariate logistic regression models were used for statistical analysis. The risk factors associated with sleep bruxism included: primary canine wear (OR=2.3 IC 95% 1.2-4.3), biting of objects like pencils or pens (OR=2.0 IC 95% 1.2-3.3) and wake-time bruxism (tooth clenching) (OR=2.3 IC 95% 1.2-4.3). Children that present the parafunctions of object biting and wake-time bruxism were more susceptible to sleep bruxism. PMID:23338271

  14. Use of Hypoprothrombinemia-Inducing Cephalosporins and the Risk of Hemorrhagic Events: A Nationwide Nested Case-Control Study

    PubMed Central

    Shen, Li-Jiuan; Wu, Fe-Lin Lin; Tsay, Woei; Hung, Chien-Ching; Lin, Shu-Wen

    2016-01-01

    Objective Existing data regarding the risk of hemorrhagic events associated with exposure to hypoprothrombinemia-inducing cephalosporins are limited by the small sample size. This population-based study aimed to examine the association between exposure to hypoprothrombinemia-inducing cephalosporins and hemorrhagic events using National Health Insurance Research Database in Taiwan. Design A nationwide nested case-control study. Setting National Health Insurance Research database. Participants We conducted a nested case-control study within a cohort of 6191 patients who received hypoprothrombinemia-inducing cephalosporins and other antibiotics for more than 48 hours. Multivariable conditional logistic regressions were used to calculate the adjusted odds ratio (aOR) and 95% confidence interval (CI) for hemorrhagic events associated with exposure to hypoprothrombinemia-inducing cephalosporins (overall, cumulative dose measured as defined daily dose (DDD), and individual cephalosporins). Results Within the cohort, we identified 704 patients with hemorrhagic events and 2816 matched controls. Use of hypoprothrombinemia-inducing cephalosporins was associated with increased risk of hemorrhagic events (aOR, 1.71; 95% CI, 1.42–2.06), which increased with higher cumulative doses (<3 DDDs, aOR 1.62; 3–5 DDDs, aOR 1.78; and >5 DDDs, aOR 1.89). The aOR for individual cephalosporin was 2.88 (95% CI, 2.08–4.00), 1.35 (1.09–1.67) and 4.57 (2.63–7.95) for cefmetazole, flomoxef, and cefoperazone, respectively. Other risk factors included use of anticoagulants (aOR 2.08 [95% CI, 1.64–2.63]), liver failure (aOR 1.69 [1.30–2.18]), poor nutritional status (aOR 1.41 [1.15–1.73]), and history of hemorrhagic events (aOR 2.57 [1.94–3.41]) 6 months prior to the index date. Conclusions Use of hypoprothrombinemia-inducing cephalosporins increases risk of hemorrhagic events. Close watch for hemorrhagic events is recommended when prescribing these cephalosporins, especially in

  15. Factors Associated with Injuries among Commercial Motorcyclists: Evidence from a Matched Case Control Study in Kampala City, Uganda

    PubMed Central

    Tumwesigye, Nazarius M.; Atuyambe, Lynn M.; Kobusingye, Olive K.

    2016-01-01

    Introduction Road traffic injuries are the eighth leading cause of death globally and the most affected are young people aged 15–29. By 2030 road traffic deaths will become the fifth leading cause of death unless urgent action is taken. Motorcyclists are among the most vulnerable road users and in Uganda they contribute 41% of all road traffic injuries. This paper establishes factors associated with the injuries of commercial motorcycle riders also known as boda-boda riders in Kampala, Uganda’s capital city. Methods The study was matched case-control with a case being a boda-boda rider that was seen at one of the 5 major city hospitals with a road traffic injury while a control was a boda-boda rider that was at the parking stage where the case operated from before the injury. The sample size was 289 riders per arm and data collection took 7 months. A structured questionnaire was used to collect data on background and exposing factors. Being matched case-control data conditional logistic regression was used in the analysis. Results Factors independently associated with injury among motorcyclists were younger age group, being a current alcohol drinker (OR = 2.30, 95%CI: 1.19–4.45), lower engine capacity (<100cc)(OR = 5.03, 95%CI: 2.91–8.70), riding experience of less than 3 years, not changing a motorcycle in past 1 year (OR = 2.04, 95%CI: 1.19–3.52), riding for a longer time in a day (OR = 6.05, 95%CI: 2.58–14.18) and sharing a motorcycle (OR = 8.25, 95%CI:2.62–25.9). Other factors associated with injury were low level of knowledge of traffic rules, being stopped by police for checks on condition of motorcycle/license/insurance, working till late. Recommendations More road safety sensitization is required among riders to raise awareness against sharing motorcycles, working for a longer time and alcohol consumption. Police enforcement of drink-driving laws should include riders of commercial motorcycles. Investigate the validity of motorcycle riding

  16. A case-control study of non-fatal traffic accidents on hospital patients in Bangkok metropolis.

    PubMed

    Böhning, D; Na Ayutha, R S

    1997-01-01

    Morbidity and mortality from road traffic accidents in Bangkok metropolis is high with a trend strictly increasing in time, thus establishing one of the major public health problems and targets of the Kingdom of Thailand. An unmatched case-control study was undertaken to evaluate various risk patterns connected with the occurrence of traffic accidents. 350 cases were sampled from five major hospitals distributed over the Bangkok Metropolitan area and 350 controls were included from out-patients of Rajawithi hospital. The major interest in this case-control analysis is to estimate relative risk (through odds ratio) and measure statistical significance of association between road traffic accident and the following risk factors: the demographic risk factors are age (age between 15 and 19 years has odds ratio of 8.25 [1.01, 67.72]; age above 40 is baseline), marital status (single has odds ratio of 2.74 [1.26, 5.95]; baseline is not-single), sex (males have an odds ratio of 2.05 [0.51, 8.24], occupation (salespersons have an odds ratio of 4.27 [1.47, 12.46]; baseline are office workers); the driving related exposure factors type of vehicle (motorbikers have an odds ratio of 6.22 [2.82, 13.78]; baseline are other vehicle drivers), driving time per day (odds ratio 1.35 [0.88, 2.09]) and the number of accidents in the last three years (odds ratio of 4.36 [2.51, 7.58]); the behavioral factors one hour before driving such as the consumption of alcohol (odds ratio 3.01 [1.53, 5.94]; baseline in no alcohol) and the consumption of a lot of food (odds ratio of 0.07 [0.03, 0.16]; baseline is not eating a lot before driving). The odds ratios for traffic accident when being under allergic medication and the consumption of tranquilizer were not significant. The results are consistent with current results in traffic accident research and point to target groups for potential prevention programmes in traffic accident prevention. PMID:9499466

  17. Evaluation of 16S rRNA Gene PCR Sensitivity and Specificity for Diagnosis of Prosthetic Joint Infection: a Prospective Multicenter Cross-Sectional Study

    PubMed Central

    Plouzeau, Chloé; Tande, Didier; Léger, Julie; Giraudeau, Bruno; Valentin, Anne Sophie; Jolivet-Gougeon, Anne; Vincent, Pascal; Corvec, Stéphane; Gibaud, Sophie; Juvin, Marie Emmanuelle; Héry-Arnaud, Genevieve; Lemarié, Carole; Kempf, Marie; Bret, Laurent; Quentin, Roland; Coffre, Carine; de Pinieux, Gonzague; Bernard, Louis; Burucoa, Christophe

    2014-01-01

    There is no standard method for the diagnosis of prosthetic joint infection (PJI). The contribution of 16S rRNA gene PCR sequencing on a routine basis remains to be defined. We performed a prospective multicenter study to assess the contributions of 16S rRNA gene assays in PJI diagnosis. Over a 2-year period, all patients suspected to have PJIs and a few uninfected patients undergoing primary arthroplasty (control group) were included. Five perioperative samples per patient were collected for culture and 16S rRNA gene PCR sequencing and one for histological examination. Three multicenter quality control assays were performed with both DNA extracts and crushed samples. The diagnosis of PJI was based on clinical, bacteriological, and histological criteria, according to Infectious Diseases Society of America guidelines. A molecular diagnosis was modeled on the bacteriological criterion (≥1 positive sample for strict pathogens and ≥2 for commensal skin flora). Molecular data were analyzed according to the diagnosis of PJI. Between December 2010 and March 2012, 264 suspected cases of PJI and 35 control cases were included. PJI was confirmed in 215/264 suspected cases, 192 (89%) with a bacteriological criterion. The PJIs were monomicrobial (163 cases [85%]; staphylococci, n = 108; streptococci, n = 22; Gram-negative bacilli, n = 16; anaerobes, n = 13; others, n = 4) or polymicrobial (29 cases [15%]). The molecular diagnosis was positive in 151/215 confirmed cases of PJI (143 cases with bacteriological PJI documentation and 8 treated cases without bacteriological documentation) and in 2/49 cases without confirmed PJI (sensitivity, 73.3%; specificity, 95.5%). The 16S rRNA gene PCR assay showed a lack of sensitivity in the diagnosis of PJI on a multicenter routine basis. PMID:25056331

  18. Evaluation of 16S rRNA gene PCR sensitivity and specificity for diagnosis of prosthetic joint infection: a prospective multicenter cross-sectional study.

    PubMed

    Bémer, Pascale; Plouzeau, Chloé; Tande, Didier; Léger, Julie; Giraudeau, Bruno; Valentin, Anne Sophie; Jolivet-Gougeon, Anne; Vincent, Pascal; Corvec, Stéphane; Gibaud, Sophie; Juvin, Marie Emmanuelle; Héry-Arnaud, Genevieve; Lemarié, Carole; Kempf, Marie; Bret, Laurent; Quentin, Roland; Coffre, Carine; de Pinieux, Gonzague; Bernard, Louis; Burucoa, Christophe

    2014-10-01

    There is no standard method for the diagnosis of prosthetic joint infection (PJI). The contribution of 16S rRNA gene PCR sequencing on a routine basis remains to be defined. We performed a prospective multicenter study to assess the contributions of 16S rRNA gene assays in PJI diagnosis. Over a 2-year period, all patients suspected to have PJIs and a few uninfected patients undergoing primary arthroplasty (control group) were included. Five perioperative samples per patient were collected for culture and 16S rRNA gene PCR sequencing and one for histological examination. Three multicenter quality control assays were performed with both DNA extracts and crushed samples. The diagnosis of PJI was based on clinical, bacteriological, and histological criteria, according to Infectious Diseases Society of America guidelines. A molecular diagnosis was modeled on the bacteriological criterion (≥ 1 positive sample for strict pathogens and ≥ 2 for commensal skin flora). Molecular data were analyzed according to the diagnosis of PJI. Between December 2010 and March 2012, 264 suspected cases of PJI and 35 control cases were included. PJI was confirmed in 215/264 suspected cases, 192 (89%) with a bacteriological criterion. The PJIs were monomicrobial (163 cases [85%]; staphylococci, n = 108; streptococci, n = 22; Gram-negative bacilli, n = 16; anaerobes, n = 13; others, n = 4) or polymicrobial (29 cases [15%]). The molecular diagnosis was positive in 151/215 confirmed cases of PJI (143 cases with bacteriological PJI documentation and 8 treated cases without bacteriological documentation) and in 2/49 cases without confirmed PJI (sensitivity, 73.3%; specificity, 95.5%). The 16S rRNA gene PCR assay showed a lack of sensitivity in the diagnosis of PJI on a multicenter routine basis. PMID:25056331

  19. 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

  20. Snippets From the Past: Is Flint, Michigan, the Birthplace of the Case-Control Study?

    PubMed Central

    Morabia, Alfredo

    2013-01-01

    In the summer of 1924, an outbreak of scarlet fever occurred in Flint, Michigan. Unable to trace it to the usual causes, particularly fresh milk, the Michigan Department of Health used a novel approach to disentangle the enigma: The 116 cases of scarlet fever were compared with 117 “controls” selected from neighbors of the quarantined cases and from patients at the City Health Center who had been treated for ailments unrelated to scarlet fever. The extraordinary culprit was ice cream, which had a frequent/occasional/none consumption prevalence of 60%, 34%, and 6% among the cases and 24%, 51%, and 25% among the controls, respectively. The 1925 report reads, “Detailed epidemiological investigation, by means of case histories and control histories on well persons, confirmed early suspicions and established the fact that the epidemic was spread by ice cream” (Am J Hyg. 1925;5(5):669–681). This forgotten epidemiologic study is the oldest study using the case-control design to have been resurrected thus far. The case-control study design may have been conceived simultaneously, but independently and for different purposes, in England (Janet Lane-Claypon's 1926 report on the determinants of breast cancer) and the United States. PMID:24064743

  1. 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. PMID:25762171

  2. 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.

  3. Snippets from the past: is Flint, Michigan, the birthplace of the case-control study?

    PubMed

    Morabia, Alfredo

    2013-12-15

    In the summer of 1924, an outbreak of scarlet fever occurred in Flint, Michigan. Unable to trace it to the usual causes, particularly fresh milk, the Michigan Department of Health used a novel approach to disentangle the enigma: The 116 cases of scarlet fever were compared with 117 "controls" selected from neighbors of the quarantined cases and from patients at the City Health Center who had been treated for ailments unrelated to scarlet fever. The extraordinary culprit was ice cream, which had a frequent/occasional/none consumption prevalence of 60%, 34%, and 6% among the cases and 24%, 51%, and 25% among the controls, respectively. The 1925 report reads, "Detailed epidemiological investigation, by means of case histories and control histories on well persons, confirmed early suspicions and established the fact that the epidemic was spread by ice cream" (Am J Hyg. 1925;5(5):669-681). This forgotten epidemiologic study is the oldest study using the case-control design to have been resurrected thus far. The case-control study design may have been conceived simultaneously, but independently and for different purposes, in England (Janet Lane-Claypon's 1926 report on the determinants of breast cancer) and the United States. PMID:24064743

  4. Congenital malformations and maternal drinking water supply in rural South Australia: a case-control study

    SciTech Connect

    Dorsch, M.M.; Scragg, R.K.R.; McMichael, A.J.; Baghurst, P.A.; Dyer, K.F.

    1984-04-01

    A case-control study, carried out in the Mount Gambier region of South Australia, investigated the relationship between mothers' antenatal drinking water source and malformations in offspring. It was prompted by earlier descriptive findings of a statistically significant, and localized, increase in the perinatal mortality rate in Mount Gambier, due principally to congential malformations affecting the central nervous system and multiple organ systems. Available for statistical analysis were 218 case-control pairs, from the period 1951-1979, individually matched by hospital, maternal age (+/- 2 years), parity and date of birth (+/- 1 month). Compared with women who drank only rainwater during their pregnancy (relative risk (RR) = 1.0), women who consumed principally groundwater had a statistically significant increase in risk of bearing a malformed child (RR = 2.8). statistically significant risk increases occurred specifically for malformations of the central nervous system and musculoskeletal system. Reanalysis of the data by estimated water nitrate concentration demonstrated a nearly threefold increase in risk for women who drank water containing 5-15 ppm of nitrate, and fourfold increase in risk for those consuming >15 ppm of nitrate.

  5. Chernobyl-related thyroid cancer in children of Belarus: a case-control study.

    PubMed

    Astakhova, L N; Anspaugh, L R; Beebe, G W; Bouville, A; Drozdovitch, V V; Garber, V; Gavrilin, Y I; Khrouch, V T; Kuvshinnikov, A V; Kuzmenkov, Y N; Minenko, V P; Moschik, K V; Nalivko, A S; Robbins, J; Shemiakina, E V; Shinkarev, S; Tochitskaya, S I; Waclawiw, M A

    1998-09-01

    The accident at the Chernobyl nuclear power plant on April 26, 1986, released approximately 2 EBq of 131I and other radioiodine isotopes that heavily contaminated southern Belarus. An increase in thyroid cancer reported in 1992 and attributed to the Chernobyl accident was challenged as possibly the result of intensive screening. We began a case-control study to test the hypothesis that the Chernobyl accident caused the increase in thyroid cancer. Records of childhood thyroid cancer in the national therapy centers in Minsk in 1992 yielded 107 individuals with confirmed pathology diagnoses and available for interview. Pathways to diagnosis were (1) routine endocrinological screening in 63, (2) presentation with enlarged or nodular thyroid in 25 and (3) an incidental finding in 19. Two sets of controls were chosen, one matched on pathway to diagnosis, the other representing the area of heavy fallout, both matched on age, sex and rural/urban residence in 1986. The 131I dose to the thyroid was estimated from ground deposition of 137Cs, ground deposition of 131I, a data bank of 1986 thyroid radiation measurements, questionnaires and interviews. Highly significant differences were observed between cases and controls (both sets) with respect to dose. The differences persisted within pathway to diagnosis, gender, age and year of diagnosis, and level of iodine in the soil, and were most marked in the southern portion of the Gomel region. The case-control comparisons indicate a strong relationship between thyroid cancer and estimated radiation dose from the Chernobyl accident. PMID:9728663

  6. Risk factors for erysipelas of the leg (cellulitis): case-control study

    PubMed Central

    Dupuy, Alain; Benchikhi, Hakima; Roujeau, Jean-Claude; Bernard, Philippe; Vaillant, Loïc; Chosidow, Olivier; Sassolas, Bruno; Guillaume, Jean-Claude; Grob, Jean-Jacques; Bastuji-Garin, Sylvie

    1999-01-01

    Objective To assess risk factors for erysipelas of the leg (cellulitis). Design Case-control study. Setting 7 hospital centres in France. Subjects 167 patients admitted to hospital for erysipelas of the leg and 294 controls. Results In multivariate analysis, a disruption of the cutaneous barrier (leg ulcer, wound, fissurated toe-web intertrigo, pressure ulcer, or leg dermatosis) (odds ratio 23.8, 95% confidence interval 10.7 to 52.5), lymphoedema (71.2, 5.6 to 908), venous insufficiency (2.9, 1.0 to 8.7), leg oedema (2.5, 1.2 to 5.1) and being overweight (2.0, 1.1 to 3.7) were independently associated with erysipelas of the leg. No association was observed with diabetes, alcohol, or smoking. Population attributable risk for toe-web intertrigo was 61%. Conclusion This first case-control study highlights the major role of local risk factors (mainly lymphoedema and site of entry) in erysipelas of the leg. From a public health perspective, detecting and treating toe-web intertrigo should be evaluated in the secondary prevention of erysipelas of the leg. Key messagesLocal factors are potential risks for erysipelas of the legLymphoedema and disruption of the cutaneous barrier exhibit the highest relative riskToe-web intertrigo has a high population attributable risk, and its detection and treatment may prevent up to 60% of cases of erysipelas of the leg PMID:10364117

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

    PubMed

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

    2016-06-01

    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

  8. 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

  9. 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. PMID:26828241

  10. Drug exposure and psoriasis vulgaris: case-control and case-crossover studies.

    PubMed

    Cohen, Arnon D; Bonneh, Dan Y; Reuveni, Haim; Vardy, Daniel A; Naggan, Lechaim; Halevy, Sima

    2005-01-01

    Intake of drugs is considered a risk factor for psoriasis. The aim of this study was to investigate the association between drugs and psoriasis. A case-control study including 110 patients who were hospitalized for extensive psoriasis was performed. A control group (n = 515) was defined as patients who had undergone elective surgery. A case-crossover study included 98 patients with psoriasis. Exposure to drugs was assessed during a hazard period (3 months before hospitalization) and compared to a control period in the patient's past. Data on drug sales were extracted by data mining techniques. Multivariate analyses were performed by logistic regression and conditional logistic regression. In the case-control study, psoriasis was associated with benzodiazepines (OR 6.9), organic nitrates (OR 5.0), angiotensin-converting enzyme (ACE) inhibitors (OR 4.0) and non-steroidal anti-inflammatory drugs (NSAIDs) (OR 3.7). In the case-crossover study, psoriasis was associated with ACE inhibitors (OR 9.9), beta-blockers (OR 9.9), dipyrone (OR 4.9) and NSAIDs (OR 2.1). Extensive psoriasis may be associated with intake of ACE inhibitors, NSAIDs or beta-blockers. PMID:16191849

  11. 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

  12. Global, local and focused geographic clustering for case-control data with residential histories

    PubMed Central

    Jacquez, Geoffrey M; Kaufmann, Andy; Meliker, Jaymie; Goovaerts, Pierre; AvRuskin, Gillian; Nriagu, Jerome

    2005-01-01

    Background This paper introduces a new approach for evaluating clustering in case-control data that accounts for residential histories. Although many statistics have been proposed for assessing local, focused and global clustering in health outcomes, few, if any, exist for evaluating clusters when individuals are mobile. Methods Local, global and focused tests for residential histories are developed based on sets of matrices of nearest neighbor relationships that reflect the changing topology of cases and controls. Exposure traces are defined that account for the latency between exposure and disease manifestation, and that use exposure windows whose duration may vary. Several of the methods so derived are applied to evaluate clustering of residential histories in a case-control study of bladder cancer in south eastern Michigan. These data are still being collected and the analysis is conducted for demonstration purposes only. Results Statistically significant clustering of residential histories of cases was found but is likely due to delayed reporting of cases by one of the hospitals participating in the study. Conclusion Data with residential histories are preferable when causative exposures and disease latencies occur on a long enough time span that human mobility matters. To analyze such data, methods are needed that take residential histories into account. PMID:15784151

  13. Does benzene cause multiple myeloma? An analysis of the published case-control literature

    SciTech Connect

    Bezabeh, S.; Engel, A.; Morris, C.B.; Lamm, S.H.

    1996-12-01

    Two case series and two epidemiological studies in the 1970s and 1980s suggested that benzene exposure might be a risk factor for multiple myeloma. An analysis has now been conducted of the published population-based and hospital-based case-control studies published through mid-1995 that permit examination of the relationship between multiple myeloma and benzene exposure or surrogates for benzene exposure. No increased association was found between multiple myeloma and benzene exposure or exposure to chemical groups that included benzene. The odds ratios from these analyses approximated 1.0. Exposures to petroleum products and employment in petroleum-related occupations did not appear to be risk factors for multiple myeloma. Cigarette smoking, as a surrogate of benzene exposure, was not found to be associated with multiple myeloma, while some studies of products of combustion described as {open_quotes}engine exhaust{close_quotes} did show a significant association with multiple myeloma. In toto, the population-based and hospital-based case-control literature indicated that benzene exposure was not a likely causal factor for multiple myeloma. 28 refs., 3 figs., 1 tab.

  14. Dietary carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration. Eye Disease Case-Control Study Group.

    PubMed

    Seddon, J M; Ajani, U A; Sperduto, R D; Hiller, R; Blair, N; Burton, T C; Farber, M D; Gragoudas, E S; Haller, J; Miller, D T

    1994-11-01

    OBJECTIVE--To evaluate the relationships between dietary intake of carotenoids and vitamins A, C, and E and the risk of neovascular age-related macular degeneration (AMD), the leading cause of irreversible blindness among adults. DESIGN--The multicenter Eye Disease Case-Control Study. SETTING--Five ophthalmology centers in the United States. PATIENTS--A total of 356 case subjects who were diagnosed with the advanced stage of AMD within 1 year prior to their enrollment, aged 55 to 80 years, and residing near a participating clinical center. The 520 control subjects were from the same geographic areas as case subjects, had other ocular diseases, and were frequency-matched to cases according to age and sex. MAIN OUTCOME MEASURES--The relative risk for AMD was estimated according to dietary indicators of antioxidant status, controlling for smoking and other risk factors, by using multiple logistic-regression analyses. RESULTS--A higher dietary intake of carotenoids was associated with a lower risk for AMD. Adjusting for other risk factors for AMD, we found that those in the highest quintile of carotenoid intake had a 43% lower risk for AMD compared with those in the lowest quintile (odds ratio, 0.57; 95% confidence interval, 0.35 to 0.92; P for trend = .02). Among the specific carotenoids, lutein and zeaxanthin, which are primarily obtained from dark green, leafy vegetables, were most strongly associated with a reduced risk for AMD (P for trend = .001). Several food items rich in carotenoids were inversely associated with AMD. In particular, a higher frequency of intake of spinach or collard greens was associated with a substantially lower risk for AMD (P for trend < .001). The intake of preformed vitamin A (retinol) was not appreciably related to AMD. Neither vitamin E nor total vitamin C consumption was associated with a statistically significant reduced risk for AMD, although a possibly lower risk for AMD was suggested among those with higher intake of vitamin C

  15. A comparison of case-control and family-based association methods: the example of sickle-cell and malaria.

    PubMed

    Ackerman, H; Usen, S; Jallow, M; Sisay-Joof, F; Pinder, M; Kwiatkowski, D P

    2005-09-01

    There has been much debate about the relative merits of population- and family-based strategies for testing genetic association, yet there is little empirical data that directly compare the two approaches. Here we compare case-control and transmission/disequilibrium test (TDT) study designs using a well-established genetic association, the protective effect of the sickle-cell trait against severe malaria. We find that the two methods give similar estimates of the level of protection (case-control odds ratio = 0.10, 95% confidence interval 0.03-0.23; family-based estimate of the odds ratio = 0.11, 95% confidence interval 0.04-0.25) and similar statistical significance of the result (case-control: chi2= 41.26, p= 10(-10), TDT: chi2= 39.06, p= 10(-10)) when 315 TDT cases are compared to 583 controls. We propose a family plus population control study design, which allows both case-control and TDT analysis of the cases. This combination is robust against the respective weaknesses of the case-control and TDT study designs, namely population structure and segregation distortion. The combined study design is especially cost-effective when cases are difficult to ascertain and, when the case-control and TDT results agree, offers greater confidence in the result. PMID:16138914

  16. Economic Impact of Dengue: Multicenter Study across Four Brazilian Regions

    PubMed Central

    Martelli, Celina Maria Turchi; Siqueira, Joao Bosco; Parente, Mirian Perpetua Palha Dias; Zara, Ana Laura de Sene Amancio; Oliveira, Consuelo Silva; Braga, Cynthia; Pimenta, Fabiano Geraldo; Cortes, Fanny; Lopez, Juan Guillermo; Bahia, Luciana Ribeiro; Mendes, Marcia Costa Ooteman; da Rosa, Michelle Quarti Machado; de Siqueira Filha, Noemia Teixeira; Constenla, Dagna; de Souza, Wayner Vieira

    2015-01-01

    Background Dengue is an increasing public health concern in Brazil. There is a need for an updated evaluation of the economic impact of dengue within the country. We undertook this multicenter study to evaluate the economic burden of dengue in Brazil. Methods We estimated the economic burden of dengue in Brazil for the years 2009 to 2013 and for the epidemic season of August 2012- September 2013. We conducted a multicenter cohort study across four endemic regions: Midwest, Goiania; Southeast, Belo Horizonte and Rio de Janeiro; Northeast: Teresina and Recife; and the North, Belem. Ambulatory or hospitalized cases with suspected or laboratory-confirmed dengue treated in both the private and public sectors were recruited. Interviews were scheduled for the convalescent period to ascertain characteristics of the dengue episode, date of first symptoms/signs and recovery, use of medical services, work/school absence, household spending (out-of-pocket expense) and income lost using a questionnaire developed for a previous cost study. We also extracted data from the patients’ medical records for hospitalized cases. Overall costs per case and cumulative costs were calculated from the public payer and societal perspectives. National cost estimations took into account cases reported in the official notification system (SINAN) with adjustment for underreporting of cases. We applied a probabilistic sensitivity analysis using Monte Carlo simulations with 90% certainty levels (CL). Results We screened 2,223 cases, of which 2,035 (91.5%) symptomatic dengue cases were included in our study. The estimated cost for dengue for the epidemic season (2012–2013) in the societal perspective was US$ 468 million (90% CL: 349–590) or US$ 1,212 million (90% CL: 904–1,526) after adjusting for under-reporting. Considering the time series of dengue (2009–2013) the estimated cost of dengue varied from US$ 371 million (2009) to US$ 1,228 million (2013). Conclusions The economic burden

  17. Sampling and Sample Preparation

    NASA Astrophysics Data System (ADS)

    Morawicki, Rubén O.

    Quality attributes in food products, raw materials, or ingredients are measurable characteristics that need monitoring to ensure that specifications are met. Some quality attributes can be measured online by using specially designed sensors and results obtained in real time (e.g., color of vegetable oil in an oil extraction plant). However, in most cases quality attributes are measured on small portions of material that are taken periodically from continuous processes or on a certain number of small portions taken from a lot. The small portions taken for analysis are referred to as samples, and the entire lot or the entire production for a certain period of time, in the case of continuous processes, is called a population. The process of taking samples from a population is called sampling. If the procedure is done correctly, the measurable characteristics obtained for the samples become a very accurate estimation of the population.

  18. A common 8q24 variant in prostate and breast cancer from a large nested case-control study.

    PubMed

    Schumacher, Fredrick R; Feigelson, Heather Spencer; Cox, David G; Haiman, Christopher A; Albanes, Demetrius; Buring, Julie; Calle, Eugenia E; Chanock, Stephen J; Colditz, Graham A; Diver, W Ryan; Dunning, Alison M; Freedman, Matthew L; Gaziano, John M; Giovannucci, Edward; Hankinson, Sue E; Hayes, Richard B; Henderson, Brian E; Hoover, Robert N; Kaaks, Rudolf; Key, Timothy; Kolonel, Laurence N; Kraft, Peter; Le Marchand, Loic; Ma, Jing; Pike, Malcolm C; Riboli, Elio; Stampfer, Meir J; Stram, Daniel O; Thomas, Gilles; Thun, Michael J; Travis, Ruth; Virtamo, Jarmo; Andriole, Gerald; Gelmann, Edward; Willett, Walter C; Hunter, David J

    2007-04-01

    Two recent studies independently identified polymorphisms in the 8q24 region, including a single nucleotide polymorphism (rs1447295), strongly associated with prostate cancer risk. Here, we replicate the overall association in a large nested case-control study from the National Cancer Institute Breast and Prostate Cancer Cohort Consortium using 6,637 prostate cancer cases and 7,361 matched controls. We also examine whether this polymorphism is associated with breast cancer among 2,604 Caucasian breast cancer cases and 3,118 matched controls. The rs1447295 marker was strongly associated with prostate cancer among Caucasians (P = 1.23 x 10(-13)). When we exclude the Multiethnic Cohort samples, previously reported by Freedman et al., the association remains highly significant (P = 8.64 x 10(-13)). Compared with wild-type homozygotes, carriers with one copy of the minor allele had an OR(AC) = 1.34 (99% confidence intervals, 1.19-1.50) and carriers with two copies of the minor allele had an OR(AA) = 1.86 (99% confidence intervals, 1.30-2.67). Among African Americans, the genotype association was statistically significant in men diagnosed with prostate cancer at an early age (P = 0.011) and nonsignificant for those diagnosed at a later age (P = 0.924). This difference in risk by age at diagnosis was not present among Caucasians. We found no statistically significant difference in risk when tumors were classified by Gleason score, stage, or mortality. We found no association between rs1447295 and breast cancer risk (P = 0.590). Although the gene responsible has yet to be identified, the validation of this marker in this large sample of prostate cancer cases leaves little room for the possibility of a false-positive result. PMID:17409400

  19. Long-term outcomes of major trauma without head injury in the West of Scotland: pilot case-control study.

    PubMed

    Graham, Colin A; Gordon, Malcolm W G; Roy, Christopher W; Hanlon, Philip W

    2007-02-01

    The aim of this study was to identify the outcomes of survivors of blunt major trauma (without head injury) 2 years or more following injury. The study uses a case-control design, is set in the West of Scotland and includes trauma patients treated in Greater Glasgow NHS Board hospitals. Participants consisted of patients who had sustained major trauma (injury severity score >15) with little or no head injury at least 2 years before assessment, identified from the Scottish Trauma Audit Group database, and age and sex-matched controls nominated by the index case's general practitioner. Nineteen cases and seven controls completed the study from 223 potential cases and 39 potential controls. Participants and non-participants had comparable injury severity score, probability of survival (Ps) and length of stay. American Medical Association impairment scores show survivors were more impaired than controls (25.9 vs 7.4%, P=0.043). No differences were observed in Functional Independence Measure (FIM) or Community Integration Questionnaire (CIQ) scores, although a type II error is possible. Short-form 36 (SF36) Physical Component Summary (PCS) scores of survivors showed no difference compared with controls although survivors' PCS scores were below UK and US means (P=0.008). SF36 Mental Component Summary (MCS) scores of survivors were below those of controls (45.07 vs 56.65, P=0.004) and normal values of the UK population (P=0.036). No differences in work status were noted, but small sample sizes were used. Non-head-injured survivors of major trauma in the West of Scotland have poorer health status (SF36), physically and mentally, than the UK population. They have greater impairment, but have an employment status comparable to that of the controls. The lack of differences in FIM and CIQ scores between survivors and controls may be due to small sample sizes. PMID:17198324

  20. Rare UNC13B variations and risk of schizophrenia: Whole-exome sequencing in a multiplex family and follow-up resequencing and a case-control study.

    PubMed

    Egawa, Jun; Hoya, Satoshi; Watanabe, Yuichiro; Nunokawa, Ayako; Shibuya, Masako; Ikeda, Masashi; Inoue, Emiko; Okuda, Shujiro; Kondo, Kenji; Saito, Takeo; Kaneko, Naoshi; Muratake, Tatsuyuki; Igeta, Hirofumi; Iwata, Nakao; Someya, Toshiyuki

    2016-09-01

    Rare genomic variations inherited in multiplex schizophrenia families are suggested to play a role in the genetic etiology of the disease. To identify rare variations with large effects on the risk of developing schizophrenia, we performed whole-exome sequencing (WES) in two affected and one unaffected individual of a multiplex family with 10 affected individuals. We also performed follow-up resequencing of the unc-13 homolog B (Caenorhabditis elegans) (UNC13B) gene, a potential risk gene identified by WES, in the multiplex family and undertook a case-control study to investigate association between UNC13B and schizophrenia. UNC13B coding regions (39 exons) from 15 individuals of the multiplex family and 111 affected offspring for whom parental DNA samples were available were resequenced. Rare missense UNC13B variations identified by resequencing were further tested for association with schizophrenia in two independent case-control populations comprising a total of 1,753 patients and 1,602 controls. A rare missense variation (V1525M) in UNC13B was identified by WES in the multiplex family; this variation was present in five of six affected individuals, but not in eight unaffected individuals or one individual of unknown disease status. Resequencing UNC13B coding regions identified five rare missense variations (T103M, M813T, P1349T, I1362T, and V1525M). In the case-control study, there was no significant association between rare missense UNC13B variations and schizophrenia, although single-variant meta-analysis indicated that M813T was nominally associated with schizophrenia. These results do not support a contribution of rare missense UNC13B variations to the genetic etiology of schizophrenia in the Japanese population. © 2016 Wiley Periodicals, Inc. PMID:26990377

  1. Sociodemographic characteristics of domestic violence in China: a population case-control study.

    PubMed

    Cao, YuPing; Yang, ShiChang; Wang, GuoQiang; Zhang, YaLin

    2014-03-01

    A population case-control study of domestic violence in China was conducted to examine the relationship between individual- and household-level characteristics and violence perpetration and victimization. Demographic comparisons were conducted between perpetrators and victims (n = 624), perpetrators and matched controls (n = 628), and perpetrator households and control households (n = 620). A multivariate model of demographic risk was tested, integrating individual- and household-level correlates of violence perpetration. Compared with victims, perpetrators were more likely to be older, male, and have lower levels of education. In the final model, violence perpetration was more likely among individuals who earned more income, contributed a lower proportion of the household income, had a family member who was unemployed or lived in households with an authoritarian or independent power structure. PMID:24176988

  2. Dietary and Other Risk Factors in The Aetiology of Cholelithiasis: A Case Control Study

    PubMed Central

    Daras, V.; Linos, D. A.; Kekis, V.; Tsoukas, M. M.; Golematis, V.

    1989-01-01

    We studied the effect of dietary factors and a variety of other risk factors on the development of cholelithiasis through a case control study. The study involved 96 cases and 118 age and sex matched controls. All cases and controls were interviewed with regard to a variety of risk factors and frequency of consumption of over 100 food items. Analysis was done both by chi square and a multiple logistic regression model. From all the dietry factors the only ones that showed a positive statistically signficantly (p<0.05) association was consumption of animal fat as expressed by eating all visible fat on the meat and using butter on the table. Interestingly high consumption of olive oil had a negative (protective) association with the disease. A negative association was also found with smoking and holding a job demanding hard labor. PMID:2487388

  3. Causal diagrams and the logic of matched case-control studies

    PubMed Central

    Shahar, Eyal; Shahar, Doron J

    2012-01-01

    It is tempting to assume that confounding bias is eliminated by choosing controls that are identical to the cases on the matched confounder(s). We used causal diagrams to explain why such matching not only fails to remove confounding bias, but also adds colliding bias, and why both types of bias are removed by conditioning on the matched confounder(s). As in some publications, we trace the logic of matching to a possible tradeoff between effort and variance, not between effort and bias. Lastly, we explain why the analysis of a matched case-control study – regardless of the method of matching – is not conceptually different from that of an unmatched study. PMID:22701093

  4. Performance of cancer cluster Q-statistics for case-control residential histories

    PubMed Central

    Sloan, Chantel D.; Jacquez, Geoffrey M.; Gallagher, Carolyn M.; Ward, Mary H.; Raaschou-Nielsen, Ole; Nordsborg, Rikke Baastrup; Meliker, Jaymie R.

    2012-01-01

    Few investigations of health event clustering have evaluated residential mobility, though causative exposures for chronic diseases such as cancer often occur long before diagnosis. Recently developed Q-statistics incorporate human mobility into disease cluster investigations by quantifying space- and time-dependent nearest neighbor relationships. Using residential histories from two cancer case-control studies, we created simulated clusters to examine Q-statistic performance. Results suggest the intersection of cases with significant clustering over their life course, Qi, with cases who are constituents of significant local clusters at given times, Qit, yielded the best performance, which improved with increasing cluster size. Upon comparison, a larger proportion of true positives were detected with Kulldorf’s spatial scan method if the time of clustering was provided. We recommend using Q-statistics to identify when and where clustering may have occurred, followed by the scan method to localize the candidate clusters. Future work should investigate the generalizability of these findings. PMID:23149326

  5. 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.

  6. Structural control sensors for CASES. [Control, Astrophysics and Structures Experiment in Space

    NASA Technical Reports Server (NTRS)

    Davis, Hugh W.; Sharkey, John P.; Carrington, Connie K.

    1990-01-01

    The Remote Attitude Measurement Sensor (RAMS) is currently baselined to meet two important sensor needs for CASES (Control, Astrophysics and Structures Experiment in Space). First, as a tip displacement sensor, RAMS is designed to provide accurate knowledge of the position and orientation of the boom tip assembly. Secondly, as a boom motion tracker, it is designed to monitor 43 reflective targets which are distributed along the length of the boom and provide displacment information for post facto processing. The design and operation of RAMS as these two types of sesnors are described, and attention is given to how RAMS interfaces with the CASES closed-loop control system and how systems identification is accommodated.

  7. Environmental sanitation conditions and health impact: a case-control study.

    PubMed

    Heller, Léo; Colosimo, Enrico Antonio; Antunes, Carlos Mauricio de Figueiredo

    2003-01-01

    This epidemiological investigation examines the impact of several environmental sanitation conditions and hygiene practices on diarrhea occurrence among children under five years of age living in an urban area. The case-control design was employed; 997 cases and 999 controls were included in the investigation. Cases were defined as children with diarrhea and controls were randomly selected among children under five years of age. After logistic regression adjustment, the following variables were found to be significantly associated with diarrhea: washing and purifying fruit and vegetables; presence of wastewater in the street; refuse storage, collection and disposal; domestic water reservoir conditions; feces disposal from swaddles; presence of vectors in the house and flooding in the lot. The estimates of the relative risks reached values up to 2.87. The present study revealed the feasibility of developing and implementing an adequate model to establish intervention priorities in the field of environmental sanitation. PMID:12715062

  8. 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.

  9. 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. PMID:21699022

  10. Protective effect of intradermal BCG against leprosy; a case-control study in central Brazil.

    PubMed

    Rodrigues, M L; Silva, S A; Neto, J C; de Andrade, A L; Martelli, C M; Zicker, F

    1992-09-01

    A case-control study was undertaken to evaluate the protective efficacy of intradermal BCG against leprosy in a high-endemic area of leprosy in central Brazil. Sixty-two cases and 186 controls were included in the study. Cases were all newly diagnosed leprosy patients under 16 years of age attending an outpatient health service, and all of them were schoolchildren. Three controls under 16 years old, frequency matched by sex and age group, were selected from schools geographically located in the area from which the cases came. The presence of BCG was negatively associated with leprosy, indicating a 5.3 risk of leprosy for those nonvaccinated and protective efficacy of 81%. Paucibacillary patients were more likely to have a BCG scar than multibacillary patients. PMID:1474274

  11. Correlation between Rotator Cuff Tears and Repeated Subacromial Steroid Injections: A Case-Controlled Study

    PubMed Central

    Bhatia, M; Singh, B; Nicolaou, N; Ravikumar, KJ

    2009-01-01

    INTRODUCTION Concern exists regarding potential damage to the rotator cuff from repeated corticosteroid injections into the subacromial space. PATIENTS AND METHODS In this retrospective, case-controlled study, 230 consecutive patients presenting to three orthopaedic units with subacromial impingement and investigated as an end-point with magnetic resonance imaging (MRI) of the shoulder were divided into groups having received less than three or three or more subacromial injections of corticosteroids. RESULTS With no significant difference in age and sex distribution, analysis by MRI showed no significant difference between the two groups in the incidence of rotator cuff tear (P < 1.0). CONCLUSIONS This suggests that corticosteroid use in patients with subacromial impingement should not be considered a causative factor in rotator cuff tears. PMID:19409148

  12. Statin use and risk of glioma: population-based case-control analysis.

    PubMed

    Seliger, Corinna; Meier, Christoph Rudolf; Becker, Claudia; Jick, Susan Sara; Bogdahn, Ulrich; Hau, Peter; Leitzmann, Michael Fred

    2016-09-01

    Statins have been reported to decrease the incidence of cancer, but the risk of glioma among statin users has been investigated in only two prior observational studies, both of them suggesting a modest protective effect of statins. We conducted a matched case-control study using data from the UK-based Clinical Practice Research Datalink to analyse use of statins among 2469 cases with glioma and 24,690 controls. We performed conditional logistic regression analysis to calculate relative risks, estimated as odds ratios (ORs) with 95 % confidence intervals (CIs) adjusting for multiple confounding factors. As compared with non-use of statins, use of statins was not associated with risk of glioma (OR for ≥90 prescriptions=0.75; 95 % CI 0.48-1.17). Our findings do not support previous sparse evidence of a possible inverse association between statin use and glioma risk. PMID:27041698

  13. Candidate single-nucleotide polymorphisms and cerebral palsy: A case-control study

    PubMed Central

    HE, XIAO-GUANG; PENG, QI; CHEN, YAN-HUA; HE, TING; HUANG, HUI; MA, ZE-KE; FAN, XUE-JIN; LUO, LING; LIU, SHAO-JI; LU, XIAO-MEI

    2015-01-01

    Certain genetic polymorphisms have been suggested to be associated with cerebral palsy; the candidate genes are involved in thrombophilia, inflammation and preterm labor, but the mechanism remains to be elucidated. The aim of the present study was to investigate the associations between selected single-nucleotide polymorphisms (SNPs) and cerebral palsy among children. A case-control study was conducted, including 74 infants with cerebral palsy (case group) and 99 healthy infants (control group). The distributions of the allele and genotype frequencies were examined for the total cerebral palsy patient population in addition to subgroups divided according to gestational age (preterm versus full-term). The results showed that the rs1042714 variant in adrenergic receptor β-2 (ADRB2) and heterozygosity for ADRB2 were associated with the cerebral palsy risk among the preterm infants. No significant differences in the allele or genotype frequencies were observed between the total cerebral palsy patient population and controls for the eight SNPs investigated. PMID:26623029

  14. 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).

  15. Investigation of genetic polymorphisms and smoking in a bladder cancer case-control study in Argentina.

    PubMed

    Moore, Lee E; Wiencke, John K; Bates, Michael N; Zheng, Shichun; Rey, Omar A; Smith, Allan H

    2004-08-10

    We investigated the role of glutathione S-transferase (GST) enzymes (M1, T1), methylenetetrahydrofolate (MTHFR) 677 and 1298, and the NAD(P)H:quinone oxidoreductase (NQO1) polymorphisms in a population-based bladder cancer case-control study in Argentina. Buccal cell DNA was obtained from 106 cases and 109 controls. The strongest evidence was for an interaction between NQO1 genotype and smoking. For ever smoking vs. never smoking the odds ratio was 8.6 (95% confidence interval (CI) 2.7-27), in the CC genotype, and 1.3 (95% CI 0.5-3.5) in the CT and TT genotypes combined. Also, elevated bladder cancer risks associated with GSTM1 and GSTT1 null genotypes were found in smokers. Having both null polymorphisms conferred the highest risks. The MTHFR 677 CT and TT polymorphisms appeared protective against bladder cancer. PMID:15219943

  16. Occupation and male lung cancer: a case-control study in northern Sweden.

    PubMed Central

    Damber, L A; Larsson, L G

    1987-01-01

    Using a case-control study comprising about 600 men with lung cancer in northern Sweden the potential risk of different occupations and groups of occupations was studied. Longitudinal data concerning occupation, employment, and smoking habits were obtained by questionnaires. Some occupational groups (underground miners, copper smelter workers, electricians, and plumbers) exposed to previously known lung carcinogenic agents such as radon daughters, arsenic, and asbestos, had considerably increased odds ratios, which persisted after adjustment for smoking. A slightly raised odds ratio was observed in a group of blue collar workers potentially exposed to lung carcinogenic agents; this rise in the group as a whole mainly disappeared after adjustment for smoking. Farmers and foresters had strikingly low odds ratios, which could only partly be explained by their more moderate smoking habits. The population aetiological fraction attributable to occupation was estimated as 9%. PMID:3620367

  17. Multicenter clinical trial using next-generation Internet technology

    NASA Astrophysics Data System (ADS)

    Ingeholm, Mary-Lou; Levine, Betty A.; Eichler, Florian; Tu, Huacheng; Jimenez-Sanchez, Gerardo; Moser, Hugo

    2001-08-01

    The capacity to evaluate therapies in a multi-center clinical trial for a rare disease like X-linked adrenoleukodystrophy (ALD) can be improved by establishing a network for transmitting magnetic resonance imaging (MRI) data using current Internet and Next Generation Internet (NGI) technologies. A Digital Imaging and Communications in Medicine (DICOM) 3.0 application has been installed; it functions as a storage service class provider (SCP), query/retrieve SCP and central database. Sites with query/retrieve (Q/R) service class user (SCU) applications have access to the images. Using the DICOM Q/R SCU application, timing studies of image retrieval for a standard Internet connection and an NGI connection have been conducted. Standard Internet results indicate that performance is affected by bandwidth limitation and is constrained by network traffic, inhibiting the standard Internet as a useful tool for real-time therapy evaluation. NGI results indicate a higher and more consistent data throughput. The increased transmission speed along with the promise of improved quality of service offered by the NGI connection allows for physicians to discuss the images, correlate them with other disease findings, measure disease severity, and request additional MRI studies in real-time permitting a more efficient clinical evaluation strategy. The elimination of variability of transmission speed is no less significant, allowing the physicians to reserve the time needed for such consultations.

  18. The Multi-Center Airborne Coherent Atmospheric Wind Sensor, MACAWS

    NASA Technical Reports Server (NTRS)

    Rothermel, Jeffry; Cutten, Dean R.; Hardesty, R. Michael; Menzies, Robert T.; Howell, James; Johnson, Steven C.; Tratt, David M.; Olivier, Lisa D.; Banta, Robert M.

    1997-01-01

    In 1992 the atmospheric lidar remote sensing groups of the NASA Marshall Space Flight Center, NOAA Environmental Technology Laboratory, and Jet Propulsion Laboratory began a joint collaboration to develop an airborne high-energy Doppler laser radar (lidar) system for atmospheric research and satellite validation and simulation studies. The result is the Multi-center Airborne Coherent Atmospheric Wind Sensor, MACAWS, which has the capability to remotely sense the distribution of wind and absolute aerosol backscatter in the troposphere and lower stratosphere. A factor critical to the programmatic feasibility and technical success of this collaboration has been the utilization of existing components and expertise which were developed for previous atmospheric research by the respective institutions. The motivation for the MACAWS program Is three-fold: to obtain fundamental measurements of sub-synoptic scale processes and features which may be used as a basis to improve sub-grid scale parameterizations in large-scale models; to obtain similar datasets in order to improve the understanding and predictive capabilities on the mesoscale; and to validate (simulate) the performance of existing (planned) satellite-borne sensors. Examples of the latter include participation in the validation of the NASA Scatterometer and the assessment of prospective satellite Doppler lidar for global tropospheric wind measurement. Initial flight tests were made in September 1995; subsequent flights were made in June 1996 following improvements. This paper describes the MACAWS instrument, principles of operation, examples of measurements over the eastern Pacific Ocean and western United States, and future applications.

  19. Computer Assisted Multi-Center Creation of Medical Knowledge Bases

    PubMed Central

    Giuse, Nunzia Bettinsoli; Giuse, Dario A.; Miller, Randolph A.

    1988-01-01

    Computer programs which support different aspects of medical care have been developed in recent years. Their capabilities range from diagnosis to medical imaging, and include hospital management systems and therapy prescription. In spite of their diversity these systems have one commonality: their reliance on a large body of medical knowledge in computer-readable form. This knowledge enables such programs to draw inferences, validate hypotheses, and in general to perform their intended task. As has been clear to developers of such systems, however, the creation and maintenance of medical knowledge bases are very expensive. Practical and economical difficulties encountered during this long-term process have discouraged most attempts. This paper discusses knowledge base creation and maintenance, with special emphasis on medical applications. We first describe the methods currently used and their limitations. We then present our recent work on developing tools and methodologies which will assist in the process of creating a medical knowledge base. We focus, in particular, on the possibility of multi-center creation of the knowledge base.

  20. Mycobacterium tuberculosis Pyrazinamide Resistance Determinants: a Multicenter Study

    PubMed Central

    Cabibbe, Andrea M.; Feuerriegel, Silke; Casali, Nicola; Drobniewski, Francis; Rodionova, Yulia; Bakonyte, Daiva; Stakenas, Petras; Pimkina, Edita; Augustynowicz-Kopeć, Ewa; Degano, Massimo; Ambrosi, Alessandro; Hoffner, Sven; Mansjö, Mikael; Werngren, Jim; Rüsch-Gerdes, Sabine; Niemann, Stefan; Cirillo, Daniela M.

    2014-01-01

    ABSTRACT Pyrazinamide (PZA) is a prodrug that is converted to pyrazinoic acid by the enzyme pyrazinamidase, encoded by the pncA gene in Mycobacterium tuberculosis. Molecular identification of mutations in pncA offers the potential for rapid detection of pyrazinamide resistance (PZAr). However, the genetic variants are highly variable and scattered over the full length of pncA, complicating the development of a molecular test. We performed a large multicenter study assessing pncA sequence variations in 1,950 clinical isolates, including 1,142 multidrug-resistant (MDR) strains and 483 fully susceptible strains. The results of pncA sequencing were correlated with phenotype, enzymatic activity, and structural and phylogenetic data. We identified 280 genetic variants which were divided into four classes: (i) very high confidence resistance mutations that were found only in PZAr strains (85%), (ii) high-confidence resistance mutations found in more than 70% of PZAr strains, (iii) mutations with an unclear role found in less than 70% of PZAr strains, and (iv) mutations not associated with phenotypic resistance (10%). Any future molecular diagnostic assay should be able to target and identify at least the very high and high-confidence genetic variant markers of PZAr; the diagnostic accuracy of such an assay would be in the range of 89.5 to 98.8%. PMID:25336456

  1. An International Randomized Multicenter Comparison of Nasal Potential Difference Techniques

    PubMed Central

    Solomon, George M.; Konstan, Michael W.; Wilschanski, Michael; Billings, Joanne; Sermet-Gaudelus, Isabelle; Accurso, Frank; Vermeulen, François; Levin, Elina; Hathorne, Heather; Reeves, Ginger; Sabbatini, Gina; Hill, Aubrey; Mayer-Hamblett, Nicole; Ashlock, Melissa; Clancy, John Paul

    2010-01-01

    Background: The transepithelial nasal potential difference (NPD) is used to assess cystic fibrosis transmembrane conductance regulator (CFTR) activity. Unreliability, excessive artifacts, and lack of standardization of current testing systems can compromise its use as a diagnostic test and outcome measure for clinical trials. Methods: To determine whether a nonperfusing (agar gel) nasal catheter for NPD measurement is more reliable and less susceptible to artifacts than a continuously perfusing nasal catheter, we performed a multicenter, randomized, crossover trial comparing a standardized NPD protocol using an agar nasal catheter with the same protocol using a continuously perfusing catheter. The data capture technique was identical in both protocols. A total of 26 normal adult subjects underwent NPD testing at six different centers. Results: Artifact frequency was reduced by 75% (P < .001), and duration was less pronounced using the agar catheter. The measurement of sodium conductance was similar between the two catheter methods, but the agar catheter demonstrated significantly greater CFTR-dependent hyperpolarization, because Δ zero Cl- + isoproterenol measurements were significantly more hyperpolarized with the agar catheter (224.2 ± 12.9 mV with agar vs 18.2 ± 9.1 mV with perfusion, P < .05). Conclusions: The agar nasal catheter approach demonstrates superior reliability compared with the perfusion nasal catheter method for measurement of NPD. This nonperfusion catheter method should be considered for adoption as a standardized protocol to monitor CFTR activity in clinical trials. PMID:20472865

  2. Moving the mandible in orthognathic surgery - A multicenter analysis.

    PubMed

    Thiele, Oliver C; Kreppel, Matthias; Bittermann, Gido; Bonitz, Lars; Desmedt, Maria; Dittes, Carsten; Dörre, Annegret; Dunsche, Anton; Eckert, Alexander W; Ehrenfeld, Michael; Fleiner, Bernd; Frerich, Bernhard; Gaggl, Alexander; Gerressen, Marcus; Gmelin, Leonore; Hammacher, Andreas; Haßfeld, Stefan; Heiland, Max; Hemprich, Alexander; Hidding, Johannes; Hölzle, Frank; Howaldt, Hans-Peter; Iizuka, Tateyuki; Kater, Wolfgang; Klein, Cornelius; Klein, Martin; Köhnke, Robert H; Kolk, Andreas; Kübler, Alexander C; Kübler, Norbert R; Kunkel, Martin; Kuttenberger, Johannes J; Kreusch, Thomas; Landes, Constantin; Lehner, Bernhard; Mischkowski, Robert A; Mokros, Steffen; Neff, Andreas; Nkenke, Emeka; Palm, Frank; Paulus, Gerhard W; Piesold, Jörn U; Rasse, Michael; Rodemer, Herbert; Rothamel, Daniel; Rustemeyer, Jan; Sader, Robert; Scheer, Martin; Scheffler, Birgit; Schippers, Christian; Schliephake, Henning; Schmelzeisen, Rainer; Schramm, Alexander; Spitzer, Wolfgang J; Stoll, Christian; Terheyden, Hendrik; Weingart, Dieter; Wiltfang, Jörg; Wolff, Klaus D; Ziegler, Christoph M; Zöller, Joachim E

    2016-05-01

    Orthognathic surgery has always been a classical focus of maxillofacial surgery. Since more than 100 years, various surgical techniques for mandibular repositioning have been developed and clinically tested. Since the establishment of plate and screw osteosynthesis, orthognathic surgery became more stable and safe. Nowadays, different surgical methods for mobilising the mandible are existing. This international multicenter analysis (n = 51 hospitals) is providing first evidence based data for the current use of different surgical methods. The dominating techniques were Obwegeser/dal Pont (61%) followed by Hunsuck/Epker (37%) and Perthes/Schlössmann (29%). The main osteosynthesis materials were plates (82%), bicortical screws (23.5%), or a combination of both (5.9%). 47% of all centers reported to use several surgical methods at the same time, depending on the anatomical problem and the surgeon's preference. This shows that different surgical methods seem to work as comparable, safe, and reliable procedures in everydays clinical practise. On this basis, further prospective studies could evaluate possible advantages for our patients. PMID:27017103

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

    PubMed

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

    2015-08-01

    The role of alcohol on fertility remains unclear. We aimed to investigate the association between alcohol and specific alcoholic beverages consumption and the risk of difficulty getting pregnant. We used a case-control study nested within the Seguimiento Universidad de Navarra (SUN) cohort, a prospective, dynamic and multipurpose cohort of 21,705 Spanish university graduates, followed biennially with mailed questionnaires. We identified 686 case-control pairs, matched for age and time in the cohort. Cases were women reporting difficulty getting pregnant. Controls did not consult due to difficulty conceiving and had at least one child during follow-up. After adjustment for potential confounders, we found no association between self-reported difficulty getting pregnant and the number of alcoholic beverages consumed per week, (Odds Ratio [OR] > 5 drinks/week vs. none = 1.04, 95% Confidence Interval [CI] = 0.72-1.51). No association between types of alcoholic beverage and difficulty conceiving (OR > 5 drinks of wine/week vs. none = 1.16, 95% CI = 0.72-1.88; OR > 5 drinks of beer/week vs. none = 1.06, 95% CI = 0.82-1.37; OR > 5 drinks of spirits/week vs. none = 1.24, 95% CI = 0.84-1.64) was observed. In conclusion, we found no association between alcohol intake and risk of consulting a physician due to difficulty conceiving. More studies are needed to clearly elucidate the effects of alcohol intake on women's fertility. In the meantime, recommendations about alcohol intake to couples trying to conceive have to be given cautiously. PMID:26225997

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

    PubMed Central

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

    2015-01-01

    The role of alcohol on fertility remains unclear. We aimed to investigate the association between alcohol and specific alcoholic beverages consumption and the risk of difficulty getting pregnant. We used a case-control study nested within the Seguimiento Universidad de Navarra (SUN) cohort, a prospective, dynamic and multipurpose cohort of 21,705 Spanish university graduates, followed biennially with mailed questionnaires. We identified 686 case-control pairs, matched for age and time in the cohort. Cases were women reporting difficulty getting pregnant. Controls did not consult due to difficulty conceiving and had at least one child during follow-up. After adjustment for potential confounders, we found no association between self-reported difficulty getting pregnant and the number of alcoholic beverages consumed per week, (Odds Ratio [OR] > 5 drinks/week vs. none = 1.04, 95% Confidence Interval [CI] = 0.72–1.51). No association between types of alcoholic beverage and difficulty conceiving (OR > 5 drinks of wine/week vs. none = 1.16, 95% CI = 0.72–1.88; OR > 5 drinks of beer/week vs. none = 1.06, 95% CI = 0.82–1.37; OR > 5 drinks of spirits/week vs. none = 1.24, 95% CI = 0.84–1.64) was observed. In conclusion, we found no association between alcohol intake and risk of consulting a physician due to difficulty conceiving. More studies are needed to clearly elucidate the effects of alcohol intake on women’s fertility. In the meantime, recommendations about alcohol intake to couples trying to conceive have to be given cautiously. PMID:26225997

  5. Congenital malformations and maternal drinking water supply in rural South Australia: a case-control study.

    PubMed

    Dorsch, M M; Scragg, R K; McMichael, A J; Baghurst, P A; Dyer, K F

    1984-04-01

    A case-control study, carried out in the Mount Gambier region of South Australia, investigated the relationship between mothers' antenatal drinking water source and malformations in offspring. It was prompted by earlier descriptive findings of a statistically significant, and localized, increase in the perinatal mortality rate in Mount Gambier, due principally to congenital malformations affecting the central nervous system and multiple organ systems. Available for statistical analysis were 218 case-control pairs, from the period 1951-1979, individually matched by hospital, maternal age (+/- 2 years), parity and date of birth (+/- 1 month). Compared with women who drank only rainwater during their pregnancy (relative risk (RR) = 1.0), women who consumed principally groundwater had a statistically significant increase in risk of bearing a malformed child (RR = 2.8). Statistically significant risk increases occurred specifically for malformations of the central nervous system and musculoskeletal system. Reanalysis of the data by estimated water nitrate concentration demonstrated a nearly threefold increase in risk for women who drank water containing 5-15 ppm of nitrate, and a fourfold increase in risk for those consuming greater than 15 ppm of nitrate. A seasonal gradient in risk was evident among groundwater consumers, ranging from 0.9 for babies conceived in winter, 3.0 in autumn, to 7.0 and 6.3 for spring and summer conceptions, respectively. Linear logistic regression analysis, controlling for risk factors not accounted for in the study design, showed that maternal water supply, infant's sex, and mother's area of residence all contributed significantly to the risk of malformation. These results are discussed in relation to previous experimental and human descriptive studies, suggesting a plausible mechanism for nitrate-induced teratogenesis. PMID:6711537

  6. Telomere length in blood cells and breast cancer risk: investigations in two case-control studies.

    PubMed

    Zheng, Yun-Ling; Ambrosone, Christine; Byrne, Celia; Davis, Warren; Nesline, Mary; McCann, Susan E

    2010-04-01

    Telomere dysfunction, which leads to genomic instability, is hypothesized to play a causal role in the development of breast cancer. However, the few epidemiologic studies that assessed the relationship between telomere length in blood cells and breast cancer risk have been inconsistent. We conducted two case-control studies to further understand the role of telomere length and breast cancer risk. Overall telomere lengths were measured by telomere quantitative fluorescent in situ hybridization (TQ-FISH) and telomere quantitative real-time PCR (TQ-PCR). The associations between telomere length in blood leukocytes and risk of breast cancer were examined in two breast cancer case-control studies that were conducted at Roswell Park Cancer Institute (RPCI) and Lombardi Comprehensive Cancer Center (LCCC). Using the 50th percentile value in controls as a cut point, women who had shorter telomere length were not at significantly increased risk of breast cancer compared with women who had longer telomere length in the RPCI study (odds ratio [OR] = 1.34, 95% confidence interval [CI] = 0.84-2.12), in the LCCC study (OR = 1.18, 95% CI = 0.73-1.91), or in the combined RPCI and LCCC studies (OR = 1.23, 95% CI = 0.89-1.71). There was no significant dose-response relationship across quartiles of telomere length and no significant difference when comparing women in the lowest to highest quartile of telomere length. Overall telomere length in blood leukocytes was not significantly associated with the risk of breast cancer. PMID:19543829

  7. Poorer prognosis with ethylenediaminetetraacetic acid-dependent pseudothrombocytopenia: a single-center case-control study.

    PubMed

    Ohashi-Fukuda, Naoko; Inokuchi, Ryota; Sato, Hajime; Nakamura, Kensuke; Iwagami, Masao; Wada, Tomoki; Jona, Masahiro; Hisasue, Takashi; Nakajima, Susumu; Yahagi, Naoki

    2015-04-01

    In ethylenediaminetetraacetic acid (EDTA)-dependent pseudothrombocytopenia (PTCP), automated platelet counts are lower than actual counts because of EDTA-induced aggregation. Factors contributing to the incidence of EDTA-PTCP are unknown, and no study has assessed the prognosis of EDTA-PTCP patients. This retrospective study assessed characteristics in EDTA-PTCP patients and matched controls to determine differences in prognosis. A retrospective case-control study was designed. From the University of Tokyo Hospital database, we identified patients diagnosed with EDTA-PTCP between 2009 and 2012, and performed 1:2 case:control matching for age and sex. A control group of sex- and age-matched patients was selected at random from the same database. We investigated differences in the frequency of complications, medication history, and blood transfusion history between the groups at the time of blood collection. Prognosis was evaluated using multivariate Cox regression analysis adjusting for age, sex, autoimmune disease, liver disease, and malignant tumor. We identified 104 EDTA-PTCP patients and 208 matched controls. The median age was 69.0 years (interquartile range: 54-76), with men comprising 51%. EDTA-PTCP patients had a higher frequency of malignant tumor and a lower frequency of hypertension and diabetes than controls. After adjustment for background factors, prognosis of EDTA-PTCP patients was significantly poorer than controls (hazard ratio, 11.8; 95% confidence intervals, 2.62-53.54). In conclusion, EDTA-PTCP patients had higher mortality, and EDTA-PTCP may need to be recognized as an indicator of worse prognosis. PMID:25881844

  8. Case-control study of diabetes-related genetic variants and pancreatic cancer risk in Japan

    PubMed Central

    Kuruma, Sawako; Egawa, Naoto; Kurata, Masanao; Honda, Goro; Kamisawa, Terumi; Ueda, Junko; Ishii, Hiroshi; Ueno, Makoto; Nakao, Haruhisa; Mori, Mitsuru; Matsuo, Keitaro; Hosono, Satoyo; Ohkawa, Shinichi; Wakai, Kenji; Nakamura, Kozue; Tamakoshi, Akiko; Nojima, Masanori; Takahashi, Mami; Shimada, Kazuaki; Nishiyama, Takeshi; Kikuchi, Shogo; Lin, Yingsong

    2014-01-01

    AIM: To examine whether diabetes-related genetic variants are associated with pancreatic cancer risk. METHODS: We genotyped 7 single-nucleotide polymorphisms (SNPs) in PPARG2 (rs1801282), ADIPOQ (rs1501299), ADRB3 (rs4994), KCNQ1 (rs2237895), KCNJ11 (rs5219), TCF7L2 (rs7903146), and CDKAL1 (rs2206734), and examined their associations with pancreatic cancer risk in a multi-institute case-control study including 360 cases and 400 controls in Japan. A self-administered questionnaire was used to collect detailed information on lifestyle factors. Genotyping was performed using Fluidigm SNPtype assays. Unconditional logistic regression methods were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between these diabetes-associated variants and pancreatic cancer risk. RESULTS: With the exception of rs1501299 in the ADIPOQ gene (P = 0.09), no apparent differences in genotype frequencies were observed between cases and controls. Rs1501299 in the ADPIOQ gene was positively associated with pancreatic cancer risk; compared with individuals with the AA genotype, the age- and sex-adjusted OR was 1.79 (95%CI: 0.98-3.25) among those with the AC genotype and 1.86 (95%CI: 1.03-3.38) among those with the CC genotype. The ORs remained similar after additional adjustment for body mass index and cigarette smoking. In contrast, rs2237895 in the KCNQ1 gene was inversely related to pancreatic cancer risk, with a multivariable-adjusted OR of 0.62 (0.37-1.04) among individuals with the CC genotype compared with the AA genotype. No significant associations were noted for other 5 SNPs. CONCLUSION: Our case-control study indicates that rs1501299 in the ADIPOQ gene may be associated with pancreatic cancer risk. These findings should be replicated in additional studies. PMID:25516658

  9. 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

  10. 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

  11. Validation of a home safety questionnaire used in a series of case-control studies

    PubMed Central

    Watson, Michael; Benford, Penny; Coupland, Carol; Clacy, Rose; Hindmarch, Paul; Majsak-Newman, Gosia; Deave, Toity; Kendrick, Denise

    2014-01-01

    Objective To measure the validity of safety behaviours, safety equipment use and hazards reported on a questionnaire by parents/carers with children aged under 5 years participating in a series of home safety case-control studies. Methods The questionnaire measured safety behaviours, safety equipment use and hazards being used as exposures in five case-control studies. Responses to questions were compared with observations made during a home visit. The researchers making observations were blind to questionnaire responses. Results In total, 162 families participated in the study. Overall agreement between reported and observed values of the safety practices ranged from 48.5% to 97.3%. Only 3 safety practices (stair gate at the top of stairs, stair gate at the bottom of stairs, stairs are carpeted) had substantial agreement based on the κ statistic (k=0.65, 0.72, 0.74, respectively). Sensitivity was high (≥70%) for 19 of the 30 safety practices, and specificity was high (≥70%) for 20 of the 30 practices. Overall for 24 safety practices, a higher proportion of respondents over-reported than under-reported safe practice (negative predictive value>positive predictive value). For six safety practices, a higher proportion of respondents under-reported than over-reported safe practice (negative predictive value

  12. Dietary patterns, food groups and myocardial infarction: a case-control study.

    PubMed

    Lockheart, Michael S K; Steffen, Lyn M; Rebnord, Hege Møklebust; Fimreite, Ragnhild Lekven; Ringstad, Jetmund; Thelle, Dag S; Pedersen, Jan I; Jacobs, David R

    2007-08-01

    Certain dietary patterns may be related to the risk of CVD. We hypothesised that a plant-centred dietary pattern would be associated with a reduced risk of first myocardial infarction (MI). A case-control study of Norwegian men and postmenopausal women (age 45-75 years) was performed. A FFQ was administered, generally within 3 d after incident MI (n 106 cases). Controls (n 105) were frequency matched on sex, age and geographic location. On the FFQ, 190 items were categorised into thirty-five food groups and an a priori healthy diet pattern score was created. We estimated OR using logistic regression with adjustment for energy intake, family history of heart disease, marital status, current smoking, education and age. Among food groups, the risk of MI was significantly higher per SD of butter and margarine (OR 1.66 (95 % CI 1.12, 2.46)), and lower per SD of tomatoes (OR 0.53 (95 % CI 0.35, 0.79)), high-fat fish (OR 0.57 (95 % CI 0.38, 0.86)), wine (OR 0.58 (95 % CI 0.41, 0.83)), salad (OR 0.59 (95 % CI 0.40, 0.87)), whole grain breakfast cereals (OR 0.64 (95 % CI 0.45, 0.90)), cruciferous vegetables (OR 0.66 (95 % CI 0.47, 0.93)) and non-hydrogenated vegetable oil (OR 0.68 (95 % CI 0.49, 0.95)). An abundance of cases were found to have a low a priori healthy diet pattern score. A dietary pattern emphasising nutrient-rich plant foods and high-fat fish and low in trans fatty acids was associated with decreased risk of MI among Norwegians. PMID:17391555

  13. Acceptance of living liver donation among medical students: A multicenter stratified study from Spain

    PubMed Central

    Ríos, Antonio; López-Navas, Ana Isabel; López-López, Ana Isabel; Gómez, Francisco Javier; Iriarte, Jorge; Herruzo, Rafael; Blanco, Gerardo; Llorca, Francisco Javier; Asunsolo, Angel; Sánchez-Gallegos, Pilar; Gutiérrez, Pedro Ramón; Fernández, Ana; de Jesús, María Teresa; Martínez-Alarcón, Laura; Lana, Alberto; Fuentes, Lorena; Hernández, Juan Ramón; Virseda, Julio; Yelamos, José; Bondía, José Antonio; Hernández, Antonio Miguel; Ayala, Marco Antonio; Ramírez, Pablo; Parrilla, Pascual

    2016-01-01

    AIM: To analyze the attitude of Spanish medical students toward living liver donation (LLD) and to establish which factors have an influence on this attitude. METHODS: Study type: A sociological, interdisciplinary, multicenter and observational study. Study population: Medical students enrolled in Spain (n = 34000) in the university academic year 2010-2011. Sample size: A sample of 9598 students stratified by geographical area and academic year. Instrument used to measure attitude: A validated questionnaire (PCID-DVH RIOS) was self-administered and completed anonymously. Data collection procedure: Randomly selected medical schools. The questionnaire was applied to each academic year at compulsory sessions. Statistical analysis: Student´s t test, χ2 test and logistic regression analysis. RESULTS: The completion rate was 95.7% (n = 9275). 89% (n = 8258) were in favor of related LLD, and 32% (n = 2937) supported unrelated LLD. The following variables were associated with having a more favorable attitude: (1) age (P = 0.008); (2) sex (P < 0.001); (3) academic year (P < 0.001); (4) geographical area (P = 0.013); (5) believing in the possibility of needing a transplant oneself in the future (P < 0.001); (6) attitude toward deceased donation (P < 0.001); (7) attitude toward living kidney donation (P < 0.001); (8) acceptance of a donated liver segment from a family member if one were needed (P < 0.001); (9) having discussed the subject with one's family (P < 0.001) and friends (P < 0.001); (10) a partner's opinion about the subject (P < 0.001); (11) carrying out activities of an altruistic nature; and (12) fear of the possible mutilation of the body after donation (P < 0.001). CONCLUSION: Spanish medical students have a favorable attitude toward LLD. PMID:27433093

  14. An analytical model applied to a multicenter pneumococcal enzyme-linked immunosorbent assay study.

    PubMed

    Plikaytis, B D; Goldblatt, D; Frasch, C E; Blondeau, C; Bybel, M J; Giebink, G S; Jonsdottir, I; Käyhty, H; Konradsen, H B; Madore, D V; Nahm, M H; Schulman, C A; Holder, P F; Lezhava, T; Elie, C M; Carlone, G M

    2000-06-01

    Pneumococcal conjugate vaccines will eventually be licensed after favorable results from phase III efficacy trials. After licensure of a conjugate vaccine for invasive pneumococcal disease in infants, new conjugate vaccines will likely be licensed primarily on the basis of immunogenicity data rather than clinical efficacy. Analytical methods must therefore be developed, evaluated, and validated to compare immunogenicity results accurately within and between laboratories for different vaccines. At present no analytical technique is uniformly accepted and used in vaccine evaluation studies to determine the acceptable level of agreement between a laboratory result and the assigned value for a given serum sample. This multicenter study describes the magnitude of agreement among 12 laboratories quantifying an identical series of 48 pneumococcal serum specimens from 24 individuals (quality-control sera) by a consensus immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) developed for this study. After provisional or trial antibody concentrations were assigned to the quality-control serum samples for this study, four methods for comparison of a series of laboratory-determined values with the assigned concentrations were evaluated. The percent error between assigned values and laboratory-determined concentrations proved to be the most informative of the four methods. We present guidelines that a laboratory may follow to analyze a series of quality-control sera to determine if it can reproduce the assigned antibody concentrations within an acceptable level of tolerance. While this study focused on a pneumococcal IgG ELISA, the methods that we describe are easily generalizable to other immunological assays. PMID:10834951

  15. Stevens-Johnson Syndrome Associated with Drugs and Vaccines in Children: A Case-Control Study

    PubMed Central

    Raucci, Umberto; Rossi, Rossella; Da Cas, Roberto; Rafaniello, Concita; Mores, Nadia; Bersani, Giulia; Reale, Antonino; Pirozzi, Nicola; Menniti-Ippolito, Francesca; Traversa, Giuseppe; in Drug and Children, Italian Multicenter Study Group for Vaccine Safety

    2013-01-01

    Objective Stevens-Johnson Syndrome (SJS) is one of the most severe muco-cutaneous diseases and its occurrence is often attributed to drug use. The aim of the present study is to quantify the risk of SJS in association with drug and vaccine use in children. Methods A multicenter surveillance of children hospitalized through the emergency departments for acute conditions of interest is currently ongoing in Italy. Cases with a diagnosis of SJS were retrieved from all admissions. Parents were interviewed on child’s use of drugs and vaccines preceding the onset of symptoms that led to the hospitalization. We compared the use of drugs and vaccines in cases with the corresponding use in a control group of children hospitalized for acute neurological conditions. Results Twenty-nine children with a diagnosis of SJS and 1,362 with neurological disorders were hospitalized between 1st November 1999 and 31st October 2012. Cases were more frequently exposed to drugs (79% vs 58% in the control group; adjusted OR 2.4; 95% CI 1.0–6.1). Anticonvulsants presented the highest adjusted OR: 26.8 (95% CI 8.4–86.0). Significantly elevated risks were also estimated for antibiotics use (adjusted OR 3.3; 95% CI 1.5–7.2), corticosteroids (adjusted OR 4.2; 95% CI 1.8–9.9) and paracetamol (adjusted OR 3.2; 95% CI 1.5–6.9). No increased risk was estimated for vaccines (adjusted OR: 0.9; 95% CI 0.3–2.8). Discussion Our study provides additional evidence on the etiologic role of drugs and vaccines in the occurrence of SJS in children. PMID:23874553

  16. Application of a nanotechnology antimicrobial spray to prevent lower urinary tract infection: a multicenter urology trial

    PubMed Central

    2012-01-01

    Background Catheter-associated urinary tract infection (CAUTI) is a common nosocomial device-associated infection. It is now recognized that the high infection rates were caused by the formation of biofilm on the surface of the catheters that decreases the susceptibility to antibiotics and results in anti-microbial resistance. In this study, we performed an in vitro test to explore the mechanism of biofilm formation and subsequently conducted a multi-center clinical trial to investigate the efficacy of CAUTI prevention with the application of JUC, a nanotechnology antimicrobial spray. Methods Siliconized latex urinary catheters were cut into fragments and sterilized by autoclaving. The sterilized sample fragments were randomly divided into the therapy and control group, whereby they were sprayed with JUC and distilled water respectively and dried before use. The experimental standard strains of Escherichia coli (E. coli) were isolated from the urine samples of patients. At 16 hours and 7 days of incubation, the samples were extracted for confocal laser scanning microscopy. A total of 1,150 patients were accrued in the clinical study. Patients were randomized according to the order of surgical treatment. The odd array of patients was assigned as the therapy group (JUC), and the even array of patients was assigned as the control group (normal saline). Results After 16 hours of culture, bacterial biofilm formed on the surface of sample fragments from the control group. In the therapy group, no bacterial biofilm formation was observed on the sample fragments. No significant increase in bacterial colony count was observed in the therapy group after 7 days of incubation. On the 7th day of catheterization, urine samples were collected for bacterial culture before extubation. Significant difference was observed in the incidence of bacteriuria between the therapy group and control group (4.52% vs. 13.04%, p < 0.001). Conclusions In this study, the effectiveness of JUC in

  17. The 5-HTTLPR confers susceptibility to anorexia nervosa in Han Chinese: evidence from a case-control and family-based study.

    PubMed

    Chen, Jue; Kang, Qing; Jiang, Wenhui; Fan, Juan; Zhang, Mingdao; Yu, Shunying; Zhang, Chen

    2015-01-01

    Accumulating evidence has implied that serotonin system dysfunction may be involved in the etiology of anorexia nervosa (AN). Serotonin-transporter-linked promoter region (5-HTTLPR) polymorphism is the genetic variant coding for the serotonin transporter and has a modulatory effect on its expression. This study aimed to investigate the possible association between the 5-HTTLPR and the susceptibility and severity of AN in Han Chinese using a case-control (255 patients and 351 controls) and family based study (198 trios). Eating disorder examination was used to measure the severity of AN behavioral symptoms. For the case-control study, the 5-HTTLPR showed significant association with AN in our sample (genotypic P = 0.03). The frequency of S allele was significantly higher in patients than that in controls (OR = 1.38, 95%CI: 1.06-1.79, P = 0.017). For the family-based study, the S allele of 5-HTTLPR was preferentially transmitted rather than non-transmitted from the parents to affected offspring (P = 0.013). The results of ANCOVA test revealed no significant association between the 5-HTTLPR polymorphism and severity of AN. Our findings suggested that 5-HTTLPR is able to confer susceptibility to AN in Han Chinese. PMID:25785698

  18. The 5-HTTLPR Confers Susceptibility to Anorexia Nervosa in Han Chinese: Evidence from a Case-Control and Family-Based Study

    PubMed Central

    Chen, Jue; Kang, Qing; Jiang, Wenhui; Fan, Juan; Zhang, Mingdao; Yu, Shunying; Zhang, Chen

    2015-01-01

    Accumulating evidence has implied that serotonin system dysfunction may be involved in the etiology of anorexia nervosa (AN). Serotonin-transporter-linked promoter region (5-HTTLPR) polymorphism is the genetic variant coding for the serotonin transporter and has a modulatory effect on its expression. This study aimed to investigate the possible association between the 5-HTTLPR and the susceptibility and severity of AN in Han Chinese using a case-control (255 patients and 351 controls) and family based study (198 trios). Eating disorder examination was used to measure the severity of AN behavioral symptoms. For the case-control study, the 5-HTTLPR showed significant association with AN in our sample (genotypic P = 0.03). The frequency of S allele was significantly higher in patients than that in controls (OR = 1.38, 95%CI: 1.06–1.79, P = 0.017). For the family-based study, the S allele of 5-HTTLPR was preferentially transmitted rather than non-transmitted from the parents to affected offspring (P = 0.013). The results of ANCOVA test revealed no significant association between the 5-HTTLPR polymorphism and severity of AN. Our findings suggested that 5-HTTLPR is able to confer susceptibility to AN in Han Chinese. PMID:25785698

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

    PubMed

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

    2016-04-01

    Timely recruitment of population controls in infectious disease outbreak investigations is challenging. We evaluated the timeliness and cost of using a market research panel as a sampling frame for recruiting controls in a case-control study during an outbreak of Salmonella Mikawasima in the UK in 2013. We deployed a web-survey by email to targeted members of a market research panel (panel controls) in parallel to the outbreak control team interviewing randomly selected public health staff by telephone and completing paper-based questionnaires (staff controls). Recruitment and completion of exposure history web-surveys for panel controls (n = 123) took 14 h compared to 15 days for staff controls (n = 82). The average staff-time cost per questionnaire for staff controls was £13·13 compared to an invoiced cost of £3·60 per panel control. Differences in the distribution of some exposures existed between these control groups but case-control studies using each group found that illness was associated with consumption of chicken outside of the home and chicken from local butchers. Recruiting market research panel controls offers time and resource savings. More rapid investigations would enable more prompt implementation of control measures. We recommend that this method of recruiting controls is considered in future investigations and assessed further to better understand strengths and limitations. PMID:26493476

  20. Post hoc Analysis for Detecting Individual Rare Variant Risk Associations Using Probit Regression Bayesian Variable Selection Methods in Case-Control Sequencing Studies.

    PubMed

    Larson, Nicholas B; McDonnell, Shannon; Albright, Lisa Cannon; Teerlink, Craig; Stanford, Janet; Ostrander, Elaine A; Isaacs, William B; Xu, Jianfeng; Cooney, Kathleen A; Lange, Ethan; Schleutker, Johanna; Carpten, John D; Powell, Isaac; Bailey-Wilson, Joan; Cussenot, Olivier; Cancel-Tassin, Geraldine; Giles, Graham; MacInnis, Robert; Maier, Christiane; Whittemore, Alice S; Hsieh, Chih-Lin; Wiklund, Fredrik; Catolona, William J; Foulkes, William; Mandal, Diptasri; Eeles, Rosalind; Kote-Jarai, Zsofia; Ackerman, Michael J; Olson, Timothy M; Klein, Christopher J; Thibodeau, Stephen N; Schaid, Daniel J

    2016-09-01

    Rare variants (RVs) have been shown to be significant contributors to complex disease risk. By definition, these variants have very low minor allele frequencies and traditional single-marker methods for statistical analysis are underpowered for typical sequencing study sample sizes. Multimarker burden-type approaches attempt to identify aggregation of RVs across case-control status by analyzing relatively small partitions of the genome, such as genes. However, it is generally the case that the aggregative measure would be a mixture of causal and neutral variants, and these omnibus tests do not directly provide any indication of which RVs may be driving a given association. Recently, Bayesian variable selection approaches have been proposed to identify RV associations from a large set of RVs under consideration. Although these approaches have been shown to be powerful at detecting associations at the RV level, there are often computational limitations on the total quantity of RVs under consideration and compromises are necessary for large-scale application. Here, we propose a computationally efficient alternative formulation of this method using a probit regression approach specifically capable of simultaneously analyzing hundreds to thousands of RVs. We evaluate our approach to detect causal variation on simulated data and examine sensitivity and specificity in instances of high RV dimensionality as well as apply it to pathway-level RV analysis results from a prostate cancer (PC) risk case-control sequencing study. Finally, we discuss potential extensions and future directions of this work. PMID:27312771

  1. Clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation: a meta-analysis of seven case-control studies.

    PubMed

    Yuan, Heng-Feng; Zhang, Jing; Guo, Chang-An; Yan, Zuo-Qin

    2016-02-01

    The purpose of this study was to evaluate the clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation. We searched the PubMed, Embase and Web of Science databases and included all case-control trials that reported on the clinical outcomes of osteonecrosis progression, incidence of total hip arthroplasty and improvement in Harris hip scores. Overall, seven case-control trials were included. Compared with the controls, patients treated with the bone marrow stem cells implantation treatment showed improved clinical outcomes with delayed osteonecrosis progression (odds ratio = 0.17, 95% CI: 0.09 - 0.32; p <0.001), a lower total hip arthroplasty incidence (odds ratio = 0.30, 95% CI: 0.12 - 0.72; p <0.01) and increased Harris hip scores (mean difference = 4.76, 95% CI: 1.24 - 8.28; p<0.01). The heterogeneity, publication bias, and sensitivity analyses showed no statistical difference significant differences between studies. Thus, our study suggests that autologous bone marrow stem cells implantation has a good therapeutic effect on osteonecrosis of the femoral, resulting in beneficial clinical outcomes. However, trials with larger sample sizes are needed to confirm these findings. PMID:26934241

  2. Clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation: a meta-analysis of seven case-control studies

    PubMed Central

    Yuan, Heng-feng; Zhang, Jing; Guo, Chang-an; Yan, Zuo-qin

    2016-01-01

    The purpose of this study was to evaluate the clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation. We searched the PubMed, Embase and Web of Science databases and included all case-control trials that reported on the clinical outcomes of osteonecrosis progression, incidence of total hip arthroplasty and improvement in Harris hip scores. Overall, seven case-control trials were included. Compared with the controls, patients treated with the bone marrow stem cells implantation treatment showed improved clinical outcomes with delayed osteonecrosis progression (odds ratio = 0.17, 95% CI: 0.09 – 0.32; p<0.001), a lower total hip arthroplasty incidence (odds ratio = 0.30, 95% CI: 0.12 - 0.72; p<0.01) and increased Harris hip scores (mean difference = 4.76, 95% CI: 1.24 – 8.28; p<0.01). The heterogeneity, publication bias, and sensitivity analyses showed no statistical difference significant differences between studies. Thus, our study suggests that autologous bone marrow stem cells implantation has a good therapeutic effect on osteonecrosis of the femoral, resulting in beneficial clinical outcomes. However, trials with larger sample sizes are needed to confirm these findings. PMID:26934241

  3. The SLC4A7 variant rs4973768 is associated with breast cancer risk: evidence from a case-control study and a meta-analysis.

    PubMed

    Chen, Wei; Zhong, Rong; Ming, Jie; Zou, Li; Zhu, Beibei; Lu, Xuzai; Ke, Juntao; Zhang, Yu; Liu, Li; Miao, Xiaoping; Huang, Tao

    2012-12-01

    Recent genome-wide association study has identified a genetic variant rs4973768, located in 3'-UTR of solute carrier family 4, sodium bicarbonate cotransporter, member 7 (SLC4A7), was associated with increased risk of breast cancer (BC). However, several following replication studies cannot yield consistent results. We thus conducted a hospital-based case-control study including 485 patients and 514 controls, combined a meta-analysis including 108,632 cases and 135,818 controls to explore the relationship between this variant and BC risk. Our case-control study showed that rs4973768 was significantly associated with increased BC risk with the odds ratio (OR) of 1.29 (95 % confidence interval [CI]: 1.04-1.60) under the allelic model. In addition, the meta-analysis also indicated that the variant slightly increased the risk of BC with the pooled OR of the per-allele effect being 1.08 (95 % CI: 1.04-1.11) although with significant heterogeneity between studies. Stratified analyses showed that ethnicity, sample size, and study design may explain part of the heterogeneity. Moreover, the bioinformatics analysis suggested that this variant may influence the transcriptional capacity of SLC4A7. In summary, our results showed that the SLC4A7 variant, rs4973768, is associated with risk of BC although the underlying biologic mechanism warrants further studies. PMID:23117855

  4. Low intensity vs. self-guided Internet-delivered psychotherapy for major depression: a multicenter, controlled, randomized study

    PubMed Central

    2013-01-01

    Background Major depression will become the second most important cause of disability in 2020. Computerized cognitive-behaviour therapy could be an efficacious and cost-effective option for its treatment. No studies on cost-effectiveness of low intensity vs self-guided psychotherapy has been carried out. The aim of this study is to assess the efficacy of low intensity vs self-guided psychotherapy for major depression in the Spanish health system. Methods The study is made up of 3 phases: 1.- Development of a computerized cognitive-behaviour therapy for depression tailored to Spanish health system. 2.- Multicenter controlled, randomized study: A sample (N=450 patients) with mild/moderate depression recruited in primary care. They should have internet availability at home, not receive any previous psychological treatment, and not suffer from any other severe somatic or psychological disorder. They will be allocated to one of 3 treatments: a) Low intensity Internet-delivered psychotherapy + improved treatment as usual (ITAU) by GP, b) Self-guided Internet-delivered psychotherapy + ITAU or c) ITAU. Patients will be diagnosed with MINI psychiatric interview. Main outcome variable will be Beck Depression Inventory. It will be also administered EuroQol 5D (quality of life) and Client Service Receipt Inventory (consume of health and social services). Patients will be assessed at baseline, 3 and 12 months. An intention to treat and a per protocol analysis will be performed. Discussion The comparisons between low intensity and self-guided are infrequent, and also a comparative economic evaluation between them and compared with usual treatment in primary. The strength of the study is that it is a multicenter, randomized, controlled trial of low intensity and self-guided Internet-delivered psychotherapy for depression in primary care, being the treatment completely integrated in primary care setting. Trial registration Clinical Trials NCT01611818 PMID:23312003

  5. ICA-based artifact removal diminishes scan site differences in multi-center resting-state fMRI

    PubMed Central

    Feis, Rogier A.; Smith, Stephen M.; Filippini, Nicola; Douaud, Gwenaëlle; Dopper, Elise G. P.; Heise, Verena; Trachtenberg, Aaron J.; van Swieten, John C.; van Buchem, Mark A.; Rombouts, Serge A. R. B.; Mackay, Clare E.

    2015-01-01

    Resting-state fMRI (R-fMRI) has shown considerable promise in providing potential biomarkers for diagnosis, prognosis and drug response across a range of diseases. Incorporating R-fMRI into multi-center studies is becoming increasingly popular, imposing technical challenges on data acquisition and analysis, as fMRI data is particularly sensitive to structured noise resulting from hardware, software, and environmental differences. Here, we investigated whether a novel clean up tool for structured noise was capable of reducing center-related R-fMRI differences between healthy subjects. We analyzed three Tesla R-fMRI data from 72 subjects, half of whom were scanned with eyes closed in a Philips Achieva system in The Netherlands, and half of whom were scanned with eyes open in a Siemens Trio system in the UK. After pre-statistical processing and individual Independent Component Analysis (ICA), FMRIB's ICA-based X-noiseifier (FIX) was used to remove noise components from the data. GICA and dual regression were run and non-parametric statistics were used to compare spatial maps between groups before and after applying FIX. Large significant differences were found in all resting-state networks between study sites before using FIX, most of which were reduced to non-significant after applying FIX. The between-center difference in the medial/primary visual network, presumably reflecting a between-center difference in protocol, remained statistically significant. FIX helps facilitate multi-center R-fMRI research by diminishing structured noise from R-fMRI data. In doing so, it improves combination of existing data from different centers in new settings and comparison of rare diseases and risk genes for which adequate sample size remains a challenge. PMID:26578859

  6. Use of nasal potential difference and sweat chloride as outcome measures in multicenter clinical trials in subjects with cystic fibrosis.

    PubMed

    Ahrens, Richard C; Standaert, Thomas A; Launspach, Janice; Han, Seung-Ho; Teresi, Mary E; Aitken, Moira L; Kelley, Thomas J; Hilliard, Kathleen A; Milgram, Laura J H; Konstan, Michael W; Weatherly, Mark R; McCarty, Nael A

    2002-02-01

    One of the goals of current research in cystic fibrosis (CF) is to develop treatments that correct or compensate for defects in function of the cystic fibrosis transmembrane regulator (CFTR) gene. The use of outcome measures that assess CFTR function such as nasal potential difference (NPD) measurements and sweat chloride determinations will be required to evaluate the efficacy of such treatments in multicenter clinical trials. The purpose of this work was to identify the sources and magnitude of variability in NPD and sweat chloride measurements when performed at multiple centers. For the variance component analysis presented here, we used NPD and sweat chloride measurements from 37 subjects with CF participating in a phase I, four-center clinical trial of CPX (8-cyclopentyl-1,3-dipropylxanthine), a drug intended to enhance trafficking of Delta F508 CFTR to the cell membrane. The specific techniques used to measure these outcomes were not standardized, and varied between the four sites. Variability of both NPD measurements (baseline potential difference during infusion with Ringer's solution; change in response to addition of 0.1 mM amiloride; and subsequent change in response to perfusion with low chloride solution containing 0.1 mM amiloride and 0.01 mM isoproterenol) and sweat chloride measurements differed significantly between study sites. For change in NPD, one study site had significantly greater variability (lower reproducibility) of measurement than the other three sites. For sweat chloride measurements, reproducibility was lower at two of the sites relative to the other two sites. Sample size calculations showed that lower reproducibility at one or more sites can substantially reduce the power of studies using NPD or sweat chloride determinations as outcome measures. Standardization of measurement protocols, careful operator training and certification, and ongoing monitoring of individual operator performance may help to improve reliability in

  7. Response to methylphenidate by adult and pediatric patients with attention-deficit/hyperactivity disorder: the Spanish multicenter DIHANA study

    PubMed Central

    Valdizán-Usón, JR; Cánovas-Martínez, A; De Lucas-Taracena, MT; Díaz-Atienza, F; Eddy-Ives, LS; Fernández-Jaén, A; Fernández-Pérez, M; García-Giral, M; García-Magán, P; Garraus-Oneca, M; Idiazábal-Alecha, MA; López-Benito, M; Lorenzo-Sanz, G; Martínez-Antón, J; Martínez-Granero, MA; Montañés-Rada, F; Mulas-Delgado, F; Ochando-Perales, G; Ortega-García, E; Pelaz-Antolín, A; Ramos-Quiroga, JA; Ruiz-Sanz, FC; Vaquerizo-Madrid, J; Yusta-Izquierdo, A

    2013-01-01

    Background: The purpose of this multicenter Spanish study was to evaluate the response to immediate-release methylphenidate by children and adults diagnosed with attention-deficit/hyperactivity disorder (ADHD), as well as to obtain information on current therapy patterns and safety characteristics. Methods: This multicenter, observational, retrospective, noninterventional study included 730 patients aged 4–65 years with a diagnosis of ADHD. Information was obtained based on a review of medical records for the years 2002–2006 in sequential order. Results: The ADHD predominantly inattentive subtype affected 29.7% of patients, ADHD predominantly hyperactive-impulsive was found in 5.2%, and the combined subtype in 65.1%. Overall, a significant lower Clinical Global Impression (CGI) score and mean number of DSM-IV TR (Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, Text Revision) symptoms by subtype were found after one year of treatment with immediate-release methylphenidate; CGI decreased from 4.51 to 1.69, symptoms of inattention from 7.90 to 4.34, symptoms of hyperactivity from 6.73 to 3.39, and combined subtype symptoms from 14.62 to 7.7. Satisfaction with immediate-release methylphenidate after one year was evaluated as “very satisfied” or “satisfied” by 86.90% of the sample; 25.75% of all patients reported at least one adverse effect. At the end of the study, 41.47% of all the patients treated with immediate-release methylphenidate were still receiving it, with a mean time of 3.80 years on therapy. Conclusion: Good efficacy and safety results were found for immediate-release methylphenidate in patients with ADHD. PMID:23430373

  8. The Relationship Between Distance to Water Source and Moderate-to-Severe Diarrhea in the Global Enterics Multi-Center Study in Kenya, 2008-2011.

    PubMed

    Nygren, Benjamin L; O'Reilly, Ciara E; Rajasingham, Anangu; Omore, Richard; Ombok, Maurice; Awuor, Alex O; Jaron, Peter; Moke, Fenny; Vulule, John; Laserson, Kayla; Farag, Tamer H; Nasrin, Dilruba; Nataro, James P; Kotloff, Karen L; Levine, Myron M; Derado, Gordana; Ayers, Tracy L; Lash, R Ryan; Breiman, Robert F; Mintz, Eric D

    2016-05-01

    In the developing world, fetching water for drinking and other household uses is a substantial burden that affects water quantity and quality in the household. We used logistic regression to examine whether reported household water fetching times were a risk factor for moderate-to-severe diarrhea (MSD) using case-control data of 3,359 households from the Global Enterics Multi-Center Study in Kenya in 2009-2011. We collected additional global positioning system (GPS) data for a subset of 254 randomly selected households and compared GPS-based straight line and actual travel path distances to fetching times reported by respondents. GPS-based data were highly correlated with respondent-provided times (Spearman correlation coefficient = 0.81, P < 0.0001). The median estimated one-way distance to water source was 200 m for cases and 171 for controls (Wilcoxon rank sums/Mann-Whitney P = 0.21). A round-trip fetching time of > 30 minutes was reported by 25% of cases versus 15% of controls and was significantly associated with MSD where rainwater was not used in the last 2 weeks (odds ratio = 1.97, 95% confidence interval = 1.56-2.49). These data support the United Nations definition of access to an improved water source being within 30 minutes total round-trip travel time. PMID:26928833

  9. 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. PMID:25063520

  10. Grip Force Modulation Characteristics as a Marker for Clinical Disease Progression in Individuals With Parkinson Disease: Case-Control Study

    PubMed Central

    Scherer, Reinhold; Matsuoka, Yoky; Kelly, Valerie E.

    2015-01-01

    Background Upper extremity deficits are prevalent in individuals with Parkinson disease (PD). In the early stages of PD, such deficits can be subtle and challenging to document on clinical examination. Objective The purpose of this study was to use a novel force sensor system to characterize grip force modulation, including force, temporal, and movement quality parameters, during a fine motor control task in individuals with early stage PD. Design A case-control study was conducted. Methods Fourteen individuals with early stage PD were compared with a control group of 14 healthy older adults. The relationship of force modulation parameters with motor symptom severity and disease chronicity also was assessed in people with PD. Force was measured during both precision and power grasp tasks using an instrumented twist-cap device capable of rotating in either direction. Results Compared with the control group, the PD group demonstrated more movement arrests during both precision and power grasp and longer total movement times during the power grasp. These deficits persisted when a concurrent cognitive task was added, with some evidence of force control deficits in the PD group, including lower rates of force production during the precision grasp task and higher peak forces during the power grasp task. For precision grasp, a higher number of movement arrests in single- and dual-task conditions as well as longer total movement times in the dual-task condition were associated with more severe motor symptoms. Limitations The sample was small and consisted of individuals in the early stages of PD with mild motor deficits. The group with PD was predominantly male, whereas the control group was predominantly female. Conclusion The results suggest that assessing grip force modulation deficits during fine motor tasks is possible with instrumented devices, and such sensitive measures may be important for detecting and tracking change early in the progression of PD. PMID:25476717

  11. Family-Environmental Factors Associated with Attention Deficit Hyperactivity Disorder in Chinese Children: A Case-Control Study

    PubMed Central

    du Prel Carroll, Xianming; Yi, Honggang; Liang, Yuezhu; Pang, Ke; Leeper-Woodford, Sandra; Riccardi, Patrizia; Liang, Xianhong

    2012-01-01

    Background Attention deficit hyperactivity disorder (ADHD) is one of the most common psychiatric disorders, affecting an estimated 5 to 12% of school-aged children worldwide. From 15 to 19 million Chinese children suffer from ADHD. The aim of this study was to investigate the association between family-environmental factors and ADHD in a sample of Chinese children. Methods A pair-matched, case-control study was conducted with 161 ADHD children and 161 non-ADHD children of matching age and sex, all from 5–18 years of age. The ADHD subjects and the normal controls were all evaluated via structured diagnostic interviews. We examined the association between family-environmental factors and ADHD using the conditional multiple logistic regression with backward stepwise selection to predict the associated factors of ADHD. Results Having experienced emotional abuse and being a single child were both significant factors associated with children diagnosed with ADHD. ADHD subjects were more likely to have suffered from emotional abuse (OR = 11.09, 95% CI = 2.15–57.29, P = 0.004) and have been a single child in the family (OR = 6.32, 95% CI = 2.09–19.14, P = 0.001) when compared to normal controls. The results were not modified by other confounding factors. Conclusion Our findings provide evidence that family-environmental factors are associated with ADHD among children in China. These findings, if confirmed by future research, may help to decrease ADHD by increasing the awareness of the effects of childhood emotional abuse. PMID:23209774

  12. Genetic Polymorphisms of CYP2A6 in a Case-Control Study on Bladder Cancer in Japanese Smokers.

    PubMed

    Kumondai, Masaki; Hosono, Hiroki; Orikasa, Kazuhiko; Arai, Yoichi; Arai, Tomio; Sugimura, Haruhiko; Ozono, Seiichiro; Sugiyama, Takayuki; Takayama, Tatsuya; Sasaki, Takamitsu; Hirasawa, Noriyasu; Hiratsuka, Masahiro

    2016-01-01

    Several of the procarcinogens inhaled in tobacco smoke, the primary risk factor for bladder cancer, are activated by CYP2A6. The association between the whole-gene deletion of CYP2A6 (CYP2A6*4) and a reduced risk of bladder cancer was suggested in Chinese Han smokers. However, there is no evidence for association between the risk of bladder cancer and CYP2A6 genotypes in the Japanese population. Using genomic DNA from smokers of the Japanese population (163 bladder cancer patients and 116 controls), we conducted a case-control study to assess the association between CYP2A6 polymorphisms and the risk of bladder cancer. Determination of CYP2A6 genotypes was carried out by amplifying each exon of CYP2A6 using polymerase chain reaction (PCR) and Sanger sequencing. The CYP2A6*4 allele was identified by an allele-specific PCR assay. Bladder cancer risk was evaluated using the activity score (AS) system based on CYP2A6 genotypes. The odds ratios (95% confidence interval) for the AS 0, AS 0.5, AS 1.0, and AS 1.5 groups were 0.46 (0.12-1.83), 0.43 (0.15-1.25), 0.86 (0.40-1.86), and 1.36 (0.60-3.06), respectively. In conclusion, although decreased CYP2A6 AS tended to reduce the risk of bladder cancer in Japanese smokers, no significant association was recognized in this population. However, given the relatively small size of the sample, further study is required to conclude the lack of a statistically significant association between CYP2A6 genotypes and the risk of bladder cancer. PMID:26725431

  13. Impact of Urate Level on Cardiovascular Risk in Allopurinol Treated Patients. A Nested Case-Control Study

    PubMed Central

    Søltoft Larsen, Kasper; Pottegård, Anton; Lindegaard, Hanne M.; Hallas, Jesper

    2016-01-01

    Background Gout gives rise to increased risk of cardiovascular events. Gout attacks can be effectively prevented with urate lowering drugs, and allopurinol potentially reduces cardiovascular risk. What target level of urate is required to reduce cardiovascular risk is not known. Objectives To investigate the effect of achieving target plasma urate with allopurinol on cardiovascular outcomes in a case-control study nested within long-term users of allopurinol. Methods We identified long-term users of allopurinol in Funen County, Denmark. Among these, we identified all cases of cardiovascular events and sampled 4 controls to each case from the same population. The cases and controls were compared with respect to whether they reached a urate target below 0.36 mmol/l on allopurinol. The derived odds ratios were controlled for potential confounders available from data on prescriptions, laboratory values and in- and outpatient contacts. Results No association between treatment-to-target urate level and cardiovascular events were found (adjusted odds ratio of 1.01, 95% confidence interval 0.79–1.28). No significant effect was seen in any subgroup defined by age, gender, renal function, allopurinol dose or the achieved urate level. Overall, the doses of allopurinol used in this study were low (mean ≈ 140 mg/day). Conclusion We were unable to demonstrate a link between achieved urate level in patients treated with allopurinol and risk of cardiovascular events. Possible explanations include that allopurinol doses higher than those used in this study are required to achieve cardiovascular risk reduction or that the cardiovascular effect of allopurinol is not mediated through low urate levels. It remains to be seen whether allopurinol has a dose-response relationship with cardiovascular events at higher doses. PMID:26751377

  14. Joint effect of genes and environment distorted by selection biases: implications for hospital-based case-control studies.

    PubMed

    Wacholder, Sholom; Chatterjee, Nilanjan; Hartge, Patricia

    2002-09-01

    The hospital-based case-control design enhances the response rates in studies that require the collection of biological samples from all of the participants. There are simple, established criteria for selecting controls so as to estimate the effect of a single factor without bias, but the analogous requirements for assessing an interaction are less clear. We derive these conditions by calculating the potential bias from selecting controls who were admitted for treatment of diseases related to either or both of the exposures of interest, designated as a gene variant (G) and an environmental agent (E). There is no bias in the estimate of the effect of E when G is associated with the control condition, whether causally or because of confounding. There is no bias in estimating multiplicative interaction between G and E for the disease of interest when there is no multiplicative G-E interaction for the control disease, even when the control condition is caused by G or E; if a mixture of several control diseases are used, however, the absence of G-E interaction in each individual disease does not ensure a lack of overall bias when controls are pooled. Hospital control designs are much less robust for assessing additive interaction. We conclude that the ideal control disease in a hospital-based study of gene-environment interaction is not caused by either G or E and that choosing controls from several conditions to act as a combined control group is a useful strategy. This formulation extends to the general problem of distortion of joint effects from selection biases or confounding. PMID:12223433

  15. Bus Stops and Pedestrian-Motor Vehicle Collisions in Lima, Peru: A Matched Case-Control Study

    PubMed Central

    Quistberg, D. Alex; Koepsell, Thomas D.; Johnston, Brian D.; Boyle, Linda Ng; Miranda, J. Jaime; Ebel, Beth E.

    2015-01-01

    Objective To evaluate the relationship between bus stop characteristics and pedestrian-motor vehicle collisions. Design Matched case-control study where the units of study were pedestrian crossing. Setting Random sample of 11 police commissaries in Lima, Peru. Data collection occurred from February, 2011 to September, 2011. Participants 97 intersection cases representing 1,134 collisions and 40 mid-block cases representing 469 collisions that occurred between October, 2010 and January, 2011 and their matched controls. Main Exposures Presence of a bus stop and specific bus stop characteristics. Main Outcome Occurrence of a pedestrian-motor vehicle collision. Results Intersections with bus stops were three times more likely to have a pedestrian-vehicle collision (OR 3.28, 95% CI 1.53-7.03), relative to intersections without bus stops. Both formal and informal bus stops were associated with a higher odds of a collision at intersections (OR 6.23, 95% CI 1.76-22.0 and OR 2.98, 1.37-6.49). At mid-block sites, bus stops on a bus-dedicated transit lane were also associated with collision risk (OR 2.36, 95% CI 1.02-5.42). All bus stops were located prior to the intersection, contrary to practices in most high income countries. Conclusions In urban Lima, the presence of a bus stop was associated with a three-fold increase in risk of a pedestrian collision. The highly competitive environment among bus companies may provide an economic incentive for risky practices such as dropping off passengers in the middle of traffic and jockeying for position with other buses. Bus stop placement should be considered to improve pedestrian safety. PMID:24357516

  16. The association between dental and periodontal diseases and sickle cell disease. A pilot case-control study

    PubMed Central

    Al-Alawi, Haidar; Al-Jawad, Abdulfatah; Al-Shayeb, Mahdi; Al-Ali, Ali; Al-Khalifa, Khalifa

    2014-01-01

    Objective This is a pilot case-control study conducted to investigate the prevalence of dental caries and periodontal disease and examine the possible association between oral health deterioration and SCD severity in a sample of Saudi SCD patients residing in the city of Al-Qatif, Eastern Province, Saudi Arabia. Materials and methods Dental examination to determine the Decayed, Missing and Filled Teeth index (DMFT), Community Periodontal Index (CPI), and plaque index system were recorded for 33 SCD patients and 33 age and sex-matched controls in the Al-Qatif Central Hospital, Qatif, Saudi Arabia. Self-administered surveys used to assess socio-economic status; oral health behaviors for both SCD patients and controls were recorded. In addition, the disease severity index was established for all patients with SCD. SPSS data analysis software package version 18.0 was used for statistical analysis. Numerical variables were described as mean with a standard deviation. Results Decayed teeth were significantly more in individuals with ages ranging from 18 to 38 years with SCD compared to the control group (p = 0.036) due to oral hygiene negligence. The mean number of filled teeth was significantly lower in individuals with SCD when compared to the control group (p = 0.015) due to the lack of appropriate and timely treatment reflected in the survey responses of SCD patients as 15.2% only taking oral care during hospitalization. There were differences between the cases and controls in the known caries risk factors such as income level, flossing, and brushing habit. The DMFT, CPI, and plaque index systems did not differ significantly between the SCD patients and the control group. Conclusion Data suggest that patients with SCD have increased susceptibility to dental caries, with a higher prevalence of tooth decay and lower prevalence of filled teeth. Known caries risk factors influenced oral health more markedly than did factors related to SCD. PMID:25544813

  17. Personality profiles and risk diet behaviors--a case-control study on teenagers from Timis County, Romania.

    PubMed

    Petrescu, Cristina; Vlaicu, Brigitha

    2014-01-01

    In the study we conducted we aimed at investigating the relation between personality profiles and risk diet behaviors in teenagers. This study was a case-control one and we applied 2 questionnaires (Freiburg Personality Inventory--FPI with 212 items) and CORT 2004 (items Q94-Q116 of diet behavior) on a sample of 2908 teenagers (51.5% girls and 48.5% boys). Cronbach's alpha index was 0.802 for FPI and 0.730 for items Q101-Q109 of CORT. Personality profiles were built by an Excel 2003 Program. Statistical analysis was realized with SPSS 16 program applying Chi square (chi2) and gamma (gamma) correlation. Personality features of teenagers with high and without risk diet behavior were analyzed. Results obtained: personality profiles and statistical results indicated the existence of a significant statistical difference of aggressiveness and domination between teenagers with high and no consumption of butter and/or lard (Q103) (chi2 = 6.872, Sig. 0.032 and chi2 = 6.922, Sig. 0.031 respectively), of juices from the market (Q106) (chi2 = 9.055, Sig. 0.011 and chi2 = 14.571, Sig. 0.001 respectively). Aggressiveness correlated with consumption of fried potatoes (Q109) (chi2 = 6.144, Sig. 0.046) too. Correlation gamma indicated direct proportional relations of aggressiveness with: Q103 (gamma = 0.215, Sig. 0.017), Q106 (gamma = 0.224, Sig. 0.004), Q109 (gamma = 0.242, Sig. 0.012); and of domination with: Q103 (gamma = 0.234, Sig. 0.008), Q106 (gamma = 0.073, Sig. 0.000). In conclusion, there is a direct proportional relation between consumption of: butter/lard, juices from the market and teenagers' aggressiveness, domination; and a similar relation between consumption of fried potatoes and aggressiveness. PMID:25076722

  18. Intestinal Protozoal Parasites in Diarrheal Children and Associated Risk Factors at Yirgalem Hospital, Ethiopia: A Case-Control Study

    PubMed Central

    Abunna, Fufa; Girma, Mekonnen

    2014-01-01

    Aim. A case-control study was conducted to determine the prevalence of G. lamblia, Cryptosporidium, spp and E. histolytica/dispar in diarrheal children at Yirgalem Hospital from February 2011 to August. Subjects and Methods. A total of 230 children participated in the study of which 115 (50%) were cases and 115 (50%) were controls. A single stool sample was collected and examined by direct saline wet mount, formol-ether concentration, and modified Ziehl-Neelsen. Results. Eighty-four (36.52%) were positive for at least one intestinal parasites (57 (49.56%) from diarrheal children and 27 (23.47%) out of nondiarrheal children). The prevalence of G. lamblia, Cryptosporidium spp, and E. histolytica/dispar was 15.65%, 9.56%, and 4.35% in children with diarrhea and 1.74%, 5.21%, and 1.74% in those without it, respectively. Cryptosporidium spp and E. histolytica/dispar revealed higher infection in males (10.81% and 5.4%, resp.) than in females (7.32% and 2.43%, resp.). G. lamblia infection was higher in females (29.27%) than in males (8.11%). Cryptosporidium spp infection was higher in the age groups of ≤4 years old (53.84%). Significant difference was seen between 10 and 13 (7.69%) years old. Higher prevalence of E. histolytica/dispar was found in 5–9 years (85.71%) than ≤4 years old (14.28%). Conclusion. Cryptosporidium spp, E. histolytica/dispar, and G. lamblia were higher in children with diarrhea than in those without it. PMID:27355052

  19. Tea, coffee, and caffeine and early-onset basal cell carcinoma in a case-control study

    PubMed Central

    Ferrucci, Leah M.; Cartmel, Brenda; Molinaro, Annette M.; Leffell, David J.; Bale, Allen E.; Mayne, Susan T.

    2014-01-01

    Objectives Tea and coffee are hypothesized to play a protective role in skin carcinogenesis via bioactive components, such as caffeine, yet the epidemiologic evidence is mixed. Existing data supports an inverse association with basal cell carcinoma (BCC) more so than for melanoma or squamous cell carcinoma. To understand if tea, coffee, and caffeine are related to early-onset BCC, we evaluated data from 767 non-Hispanic Whites under age 40 in a case-control study in Connecticut. Methods BCC cases (n=377) were identified through Yale's Dermatopathology database. Controls (n=390) were randomly sampled from individuals in the same database with benign skin diagnoses and frequency matched to cases on age, gender, and biopsy site. Subjects completed an in-person interview including assessment of caffeinated coffee and hot tea. We calculated multivariate odds ratios (OR) and 95% confidence intervals (CIs) with unconditional logistic regression for regular consumption and frequency and duration measures. Results Combined regular consumption of caffeinated coffee plus hot tea was inversely associated with early-onset BCC (OR=0.60, 95% CI=0.38–0.96). Those in the highest category of caffeine from these sources had a 43% reduced risk of BCC compared to non-consumers (OR=0.57, 95% CI=0.34–0.95, p-trend=0.037). Conclusions Our findings suggest a modest protective effect for caffeinated coffee plus tea in relation to early-onset BCC that may, in part, be due to caffeine. This study adds to the growing body of literature suggesting potential health benefits from these beverages. PMID:24841641

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

    PubMed Central

    van der Woude, Fokke J; Heinemann, Lothar AJ; Graf, Helmut; Lewis, Michael; Moehner, Sabine; Assmann, Anita; Kühl-Habich, Doerthe

    2007-01-01

    Background An ad hoc peer-review committee was jointly appointed by Drug Authorities and Industry in Germany, Austria and Switzerland in 1999/2000 to review the evidence for a causal relation between phenacetin-free analgesics and nephropathy. The committee found the evidence as inconclusive and requested a new case-control study of adequate design. Methods We performed a population-based case-control study with incident cases of end-stage renal disease (ESRD) under the age of 50 years and four age and sex-matched neighborhood controls in 170 dialysis centers (153 in Germany, and 17 in Austria) from January 1, 2001 to December 31, 2004. Data on lifetime medical history, risk factors, treatment, job exposure and intake of analgesics were obtained in a standardized face-to-face interview using memory aids to enhance accuracy. Study design, study performance, analysis plan, and study report were approved by an independent international advisory committee and by the Drug Authorities involved. Unconditional logistic regression analyses were performed. Results The analysis included 907 cases and 3,622 controls who had never used phenacetin-containing analgesics in their lifetime. The use of high cumulative lifetime dose (3rd tertile) of analgesics in the period up to five years before dialysis was not associated with later ESRD. Adjusted odds ratios with 95% confidence intervals were 0.8 (0.7 – 1.0) and 1.0 (0.8 – 1.3) for ever- compared with no or low use and high use compared with low use, respectively. The same results were found for all analgesics and for mono-, and combination preparations with and without caffeine. No increased risk was shown in analyses stratifying for dose and duration. Dose-response analyses showed that analgesic use was not associated with an increased risk for ESRD up to 3.5 kg cumulative lifetime dose (98 % of the cases with ESRD). While the large subgroup of users with a lifetime dose up to 0.5 kg (278 cases and 1365 controls) showed a

  1. The Multi-center Airborne Coherent Atmospheric Wind Sensor.

    NASA Astrophysics Data System (ADS)

    Rothermel, Jeffry; Cutten, Dean R.; Hardesty, R. Michael; Menzies, Robert T.; Howell, James N.; Johnson, Steven C.; Tratt, David M.; Olivier, Lisa D.; Banta, Robert M.

    1998-04-01

    In 1992 the atmospheric lidar remote sensing groups of the National Aeronautics and Space Administration Marshall Space Flight Center, the National Oceanic and Atmospheric Administration/Environmental Technology Laboratory (NOAA/ETL), and the Jet Propulsion Laboratory began a joint collaboration to develop an airborne high-energy Doppler laser radar (lidar) system for atmospheric research and satellite validation and simulation studies. The result is the Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS), which has the capability to remotely sense the distribution of wind and absolute aerosol backscatter in three-dimensional volumes in the troposphere and lower stratosphere.A factor critical to the programmatic feasibility and technical success of this collaboration has been the utilization of existing components and expertise that were developed for previous atmospheric research by the respective institutions. For example, the laser transmitter is that of the mobile ground-based Doppler lidar system developed and used in atmospheric research for more than a decade at NOAA/ETL.The motivation for MACAWS is threefold: 1) to obtain fundamental measurements of subsynoptic-scale processes and features to improve subgrid-scale parameterizations in large-scale models, 2) to obtain datasets in order to improve the understanding of and predictive capabilities for meteorological systems on subsynoptic scales, and 3) to validate (simulate) the performance of existing (planned) satellite-borne sensors.Initial flight tests were made in September 1995; subsequent flights were made in June 1996 following system improvements. This paper describes the MACAWS instrument, principles of operation, examples of measurements over the eastern Pacific Ocean and western United States, and future applications.

  2. Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS)

    NASA Astrophysics Data System (ADS)

    Rhothermel, Jeffry; Jones, W. D.; Dunkin, J. A.; McCaul, E. W., Jr.

    1993-01-01

    This effort involves development of a calibrated, pulsed coherent CO2 Doppler lidar, followed by a carefully-planned and -executed program of multi-dimensional wind velocity and aerosol backscatter measurements from the NASA DC-8 research aircraft. The lidar, designated as the Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS), will be applicable to two research areas. First, MACAWS will enable specialized measurements of atmospheric dynamical processes in the planetary boundary layer and free troposphere in geographic locations and over scales of motion not routinely or easily accessible to conventional sensors. The proposed observations will contribute fundamentally to a greater understanding of the role of the mesoscale, helping to improve predictive capabilities for mesoscale phenomena and to provide insights into improving model parameterizations of sub-grid scale processes within large-scale circulation models. As such, it has the potential to contribute uniquely to major, multi-institutional field programs planned for the mid 1990's. Second, MACAWS measurements can be used to reduce the degree of uncertainty in performance assessments and algorithm development for NASA's prospective Laser Atmospheric Wind Sounder (LAWS), which has no space-based instrument heritage. Ground-based lidar measurements alone are insufficient to address all of the key issues. To minimize costs, MACAWS is being developed cooperatively by the lidar remote sensing groups of the Jet Propulsion Laboratory, NOAA Wave Propagation Laboratory, and MSFC using existing lidar hardware and manpower resources. Several lidar components have already been exercised in previous airborne lidar programs (for example, MSFC Airborne Doppler Lidar System (ADLS) used in 1981,4 Severe Storms Wind Measurement Program; JPL Airborne Backscatter Lidar Experiment (ABLE) used in 1989,90 Global Backscatter Experiment Survey Missions). MSFC has been given responsibility for directing the overall

  3. Multicenter assessment of burn team injury prevention knowledge.

    PubMed

    Klas, Karla S; Smith, Sue Jane; Matherly, Annette F; Dillard, B Daniel; Grant, Ernest J; Cusick-Jost, Janet

    2015-01-01

    Engaging burn professionals to utilize "teachable moments" and provide accurate fire safety and burn prevention (FSBP) education is essential in reducing injury incidence. Minimal data is available regarding burn clinicians' evidence-based FSBP knowledge. A committee of prevention professionals developed, pilot-tested, and distributed a 52-question online survey assessing six major categories: demographical information (n = 7); FSBP knowledge (n = 24); home FSBP practices (n = 6); burn center FSBP education (n = 7); self-assessed competence and confidence in providing FSBP education (n = 2); and improving ABA reach (n = 6). Responses with <50% completion of FSBP knowledge section were excluded. Total group's (TG) mean FSBP score of 61.5% was used to define and compare underperformers (UP). After excluding 36 incomplete responses, test scores ranged: TG (n = 427) 21-88% and UP (n = 183) 21-58%. Ten FSBP knowledge questions covering seven topics were incorrectly answered by >50% of TG. ANOVA showed self-reported competence and confidence in providing FSBP education were not good predictors of FSBP scores, but staff with <2 years experience scored lower. Over 90% of TG wants FSBP fact sheets for patient education. Burn professionals have a responsibility to educate patients, families, and communities on FSBP. Team members report competence and confidence in their ability to provide FSBP education. However, this multicenter survey demonstrates the need for professional training on best practices in injury prevention, specifically targeting knowledge gaps on: smoke alarms, fire-safe cigarettes, children's sleepwear, burn/fire epidemiology, fireworks, bathing/scald injuries, and residential sprinklers. Based on these findings, FSBP educational materials will be created. PMID:25094010

  4. Ongoing monitoring of data clustering in multicenter studies

    PubMed Central

    2012-01-01

    Background Multicenter study designs have several advantages, but the possibility of non-random measurement error resulting from procedural differences between the centers is a special concern. While it is possible to address and correct for some measurement error through statistical analysis, proactive data monitoring is essential to ensure high-quality data collection. Methods In this article, we describe quality assurance efforts aimed at reducing the effect of measurement error in a recent follow-up of a large cluster-randomized controlled trial through periodic evaluation of intraclass correlation coefficients (ICCs) for continuous measurements. An ICC of 0 indicates the variance in the data is not due to variation between the centers, and thus the data are not clustered by center. Results Through our review of early data downloads, we identified several outcomes (including sitting height, waist circumference, and systolic blood pressure) with higher than expected ICC values. Further investigation revealed variations in the procedures used by pediatricians to measure these outcomes. We addressed these procedural inconsistencies through written clarification of the protocol and refresher training workshops with the pediatricians. Further data monitoring at subsequent downloads showed that these efforts had a beneficial effect on data quality (sitting height ICC decreased from 0.92 to 0.03, waist circumference from 0.10 to 0.07, and systolic blood pressure from 0.16 to 0.12). Conclusions We describe a simple but formal mechanism for identifying ongoing problems during data collection. The calculation of the ICC can easily be programmed and the mechanism has wide applicability, not just to cluster randomized controlled trials but to any study with multiple centers or with multiple observers. PMID:22413923

  5. Neurophysiology versus clinical genetics in Rett syndrome: A multicenter study.

    PubMed

    Halbach, Nicky; Smeets, Eric E; Julu, Peter; Witt-Engerström, Ingegerd; Pini, Giorgio; Bigoni, Stefania; Hansen, Stig; Apartopoulos, Flora; Delamont, Robert; van Roozendaal, Kees; Scusa, Maria F; Borelli, Paolo; Candel, Math; Curfs, Leopold

    2016-09-01

    Many studies have attempted to establish the genotype-phenotype correlation in Rett syndrome (RTT). Cardiorespiratory measurements provide robust objective data, to correlate with each of the different clinical phenotypes. It has important implications for the management and treatment of this syndrome. The aim of this study was to correlate the genotype with the quantitative cardiorespiratory data obtained by neurophysiological measurement combined with a clinical severity score. This international multicenter study was conducted in four European countries from 1999 to 2012. The study cohort consisted of a group of 132 well-defined RTT females aged between 2 and 43 years with extended clinical, molecular, and neurophysiological assessments. Diagnosis of RTT was based on the consensus criteria for RTT and molecular confirmation. Genotype-phenotype analyses of clinical features and cardiorespiratory data were performed after grouping mutations by the same type and localization or having the same putative biological effect on the MeCP2 protein, and subsequently on eight single recurrent mutations. A less severe phenotype was seen in females with CTS, p.R133C, and p.R294X mutations. Autonomic disturbances were present in all females, and not restricted to nor influenced by one specific group or any single recurrent mutation. The objective information from non-invasive neurophysiological evaluation of the disturbed central autonomic control is of great importance in helping to organize the lifelong care for females with RTT. Further research is needed to provide insights into the pathogenesis of autonomic dysfunction, and to develop evidence-based management in RTT. © 2016 Wiley Periodicals, Inc. PMID:27354166

  6. Analytically reduced form of multicenter integrals from Gaussian transforms. [in atomic and molecular physics

    NASA Technical Reports Server (NTRS)

    Straton, Jack C.

    1989-01-01

    The four-dimensional Fourier-Feynman transformations previously used in analytically reducing the general class of integrals containing multicenter products of 1s hydrogenic orbitals, Coulomb or Yukawa potentials, and plane waves, are replaced by the one-dimensional Gaussian transformation. This reduces the previously required double-diagonalization of the quadratic form of the multicenter integrals to only one diagonalization, yielding a simpler reduced form of the integral. The present work also extends the result to include all s states and pairs of states with l not equal to zero summed over the m quantum number.

  7. An overview of the North American residential radon and lung cancer case-control studies.

    PubMed

    Field, R William; Krewski, Daniel; Lubin, Jay H; Zielinski, Jan M; Alavanja, Michael; Catalan, Vanessa S; Klotz, Judith B; Létourneau, Ernest G; Lynch, Charles F; Lyon, Joseph L; Sandler, Dale P; Schoenberg, Janet B; Steck, Daniel J; Stolwijk, Jan A; Weinberg, Clarice; Wilcox, Homer B

    2006-04-01

    Lung cancer has held the distinction as the most common cancer type worldwide since 1985 (Parkin et al., 1993). Recent estimates suggest that lung cancer accounted for 1.2 million deaths worldwide in 2002, which represents 17.6% of the global cancer deaths (Parkin et al., 2005). During 2002, the highest lung cancer rates for men worldwide reportedly occurred in North America and Eastern Europe, whereas the highest rates in females occurred in North America and Northern Europe (Parkin et al., 2005). While tobacco smoking is the leading risk factor for lung cancer, because of the magnitude of lung cancer mortality, even secondary causes of lung cancer present a major public health concern (Field, 2001). Extrapolations from epidemiologic studies of radon-exposed miners project that approximately 18,600 lung cancer deaths per year (range 3000 to 41,000) in the United States alone are attributable to residential radon progeny exposure (National Research Council, 1999). Because of differences between the mines and the home environment, as well as differences (such as breathing rates) between miners and the general public, there was a need to directly evaluate effects of radon in homes. Seven major residential case-control radon studies have been conducted in North America to directly examine the association between prolonged radon progeny (radon) exposure and lung cancer. Six of the studies were performed in the United States including studies in New Jersey, Missouri (two studies), Iowa, and the combined states study (Connecticut, Utah, and southern Idaho). The seventh study was performed in Winnipeg, Manitoba, Canada. The residential case-control studies performed in the United States were previously reviewed elsewhere (Field, 2001). The goal of this review is to provide additional details regarding the methodologies and findings for the individual studies. Radon concentration units presented in this review adhere to the types (pCi/L or Bq/m3) presented in the

  8. A Metagenomics and Case-Control Study To Identify Viruses Associated with Bovine Respiratory Disease

    PubMed Central

    Kondov, Nikola O.; Deng, Xutao; Van Eenennaam, Alison; Neibergs, Holly L.

    2015-01-01

    approach, we characterized the viruses in respiratory secretions from BRD cases and identified known and previously uncharacterized viruses belonging to seven viral families. Using a case-control format with location-matched animals, we compared the rates of viral detection and identified 3 viruses associated with severe BRD signs. Combining a metagenomics and case-control format can provide candidate pathogens associated with complex infectious diseases and inform further studies aimed at reducing their impact. PMID:25740998

  9. Case-control study of sudden infant death syndrome in Lithuania, 1997–2000

    PubMed Central

    Bubnaitienė, Vilija; Kalėdienė, Ramunė; Kėvalas, Rimantas

    2005-01-01

    Background To identify risk factors for sudden infant death syndrome relevant in Lithuania. Methods A nationwide case-control study surveying parents of 35 infants who died from sudden infant death syndrome during the period of 1997–2000 and parents of 145 control infants matched with SIDS infants for date of birth and for region of birth was carried out. Results Deaths incidence was greater in the warm period (60%) vs. cold period (40%). Prone and side sleeping positions both carried no increased risk of sudden infant death syndrome compared with supine because of a rare prone sleeping (4.1% of controls vs. 0% of dead infants) and more prevalent side than supine sleeping (84.8% of controls vs. 94.3% of dead infants) in the controls as well as the cases. Bed sharing for the whole night as a risk factor for sudden infant death syndrome has not been confirmed, either, as bed sharing was common only for the controls (13.8% of controls vs. 0% of dead infants). Routine sleeping environment factors such as heavy wrapping (≥4 togs) of an infant (odds ratio 8.49; 95% confidence interval 2.38 to 30.32), sleeping in a bassinet (4.22; 1.16 to 15.38) and maternal factors such as maternal education ≤12 years (4.48; 1.34 to 14.94), unplanned pregnancy (5.22; 1.49 to 18.18) and ≥2 previous live births (3.90; 1.00 to 15.10) were significantly associated with sudden infant death syndrome on multivariate analysis. Conclusion The results of this first population-based case-control study have shed some light on the epidemiology of the syndrome in Lithuania. Although the mortality of sudden infant death syndrome in Lithuania is not high, it might be lowered moreover by public informing about sudden infant death syndrome and related risk factors. Special attention must be paid to mothers with low education on potentially modifiable risk factors such as routine heavy wrapping of an infant during sleep, routine sleeping in a bassinet and unplanned pregnancy. PMID:16283946

  10. MGMT Leu84Phe Polymorphism Contributes to Cancer Susceptibility: Evidence from 44 Case-Control Studies

    PubMed Central

    Yu, Cuicui; Sun, Yan; Jia, Chuanliang; Zhang, Lijing; Salahuddin, Taufiq; Li, Xiaodong; Lang, Juntian; Song, Xicheng

    2013-01-01

    Background O6-methylguanine-DNA methyltransferase is one of the few proteins to directly remove alkylating agents in the human DNA direct reversal repair pathway. A large number of case-control studies have been conducted to explore the association between MGMT Leu84Phe polymorphism and cancer risk. However, the results were not consistent. Methods We carried out a meta-analysis of 44 case-control studies to clarify the association between the Leu84Phe polymorphism and cancer risk. Results Overall, significant association of the T allele with cancer susceptibility was verified with meta-analysis under a recessive genetic model (P<0.001, OR=1.30, 95%CI 1.24-1.50) and TT versus CC comparison (P=0.001, OR=1.29, 95% CI 1.12-1.50). In subgroup analysis, a significant increased risk was found for lung cancer (TT versus CC, P=0.027, OR=1.67, 95% CI 1.06-2.63; recessive genetic model, P=0.32, OR=1.64, 95% CI 1.04-2.58), whereas risk of colorectal cancer was significantly low under a dominant genetic model (P=0.019, OR=0.84, 95% CI 0.72-0.97). Additionally, a significant association between TT genetic model and total cancer risk was found in the Caucasian population (TT versus CC, P=0.014, OR=1.29, 95% CI 1.05-1.59; recessive genetic model, P=0.009, OR=1.31, 95% CI 1.07-1.61), but not in the Asian population. An increased risk for lung cancer was also verified in the Caucasian population (TT versus CC, P=0.035, OR=1.62, 95% CI 1.04-2.53; recessive genetic model, P=0.048, OR=1.57, 95% CI 1.01-2.45). Conclusions These results suggest that MGMT Leu84Phe polymorphism might contribute to the susceptibility of certain cancers. PMID:24086516

  11. 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

  12. Vitamin C Intake and Pancreatic Cancer Risk: A Meta-Analysis of Published Case-Control and Cohort Studies

    PubMed Central

    Hua, Yong-Fei; Wang, Gao-Qing; Jiang, Wei; Huang, Jing; Chen, Guo-Chong; Lu, Cai-De

    2016-01-01

    Background Observational studies inconsistently reported the relationship between vitamin C intake and risk of pancreatic cancer. We conducted a meta-analysis of published case-control and cohort studies to quantify the association. Methods Potentially eligible studies were found on PubMed and EMBASE databases through May 31, 2015. A random-effects model was assigned to compute summary point estimates with corresponding 95% confidence intervals (CIs). Subgroup and meta-regression analyses were also performed to explore sources of heterogeneity. Results Our final analyses included 20 observational studies comprising nearly 5 thousand cases of pancreatic cancer. When comparing the highest with the lowest categories of vitamin C intake, the summary odds ratio/relative risk for case-control studies (14 studies), cohort studies (6 studies) and all studies combined was 0.58 (95% CI: 0.52–0.66), 0.93 (95% CI: 0.78–1.11) and 0.66 (95% CI: 0.58–0.75), respectively. The difference in the findings between case-control and cohort studies was statistically significant (P < .001). Possible publication bias was shown in the meta-analysis of case-control studies. Conclusion There is insufficient evidence to conclude any relationship between vitamin C intake and risk of pancreatic cancer. The strong inverse association observed in case-control studies may be affected by biases (eg, recall and selection biases) that particularly affect case-control studies and/or potential publication bias. Future prospective studies of vitamin C intake and pancreatic cancer are needed. PMID:26859881

  13. A multicenter evaluation of a new antibody test kit for lymphatic filariasis employing recombinant Brugia malayi antigen Bm-14.

    PubMed

    Weil, Gary J; Curtis, Kurt C; Fischer, Peter U; Won, Kimberly Y; Lammie, Patrick J; Joseph, Hayley; Melrose, Wayne D; Brattig, Norbert W

    2011-09-01

    Antibody tests are useful for mapping the distribution of lymphatic filariasis (LF) in countries and regions and for monitoring progress in elimination programs based on mass drug administration (MDA). Prior antibody tests have suffered from poor sensitivity and/or specificity or from a lack of standardization. We conducted a multicenter evaluation of a new commercial ELISA that detects IgG4 antibodies to the recombinant filarial antigen Bm14. Four laboratories tested a shared panel of coded serum or plasma samples that included 55 samples from people with microfilaremic Wuchereria bancrofti or Brugia infections and 26 control samples. Qualitative results were identical in all four test sites. In addition, each laboratory tested samples from their own serum banks. The test detected antibodies in 32 of 36 samples (91%) from people with Brugian filariasis and in 96 of 98 samples (98%) from people with Bancroftian filariasis. Specificity testing showed that many serum or plasma samples from patients with other filarial infections such as onchocerciasis had positive antibody tests. Specificity was otherwise excellent, although 3 of 30 samples from patients with ascariasis and 4 of 51 with strongyloidiasis had positive antibody tests; it is likely that some or all of these people had previously lived in filariasis-endemic areas. Antibody test results obtained with eluates from blood dried on filter paper were similar to those obtained with plasma tested at the same dilution. This test may be helpful for diagnosing LF in patients with clinical signs of filariasis. It may also be a useful tool for use in LF endemic countries to monitor the progress of filariasis elimination programs and for post-MDA surveillance. PMID:20430004

  14. Borderline Ovarian Tumors and Diagnostic Dilemma of Intraoperative Diagnosis: Could Preoperative He4 Assay and ROMA Score Assessment Increase the Frozen Section Accuracy? A Multicenter Case-Control Study

    PubMed Central

    Gizzo, Salvatore; Berretta, Roberto; Di Gangi, Stefania; Guido, Maria; Zanni, Giuliano Carlo; Franceschetti, Ilaria; Quaranta, Michela; Plebani, Mario; Nardelli, Giovanni Battista; Patrelli, Tito Silvio

    2014-01-01

    The aim of our study was to assess the value of a preoperative He4-serum-assay and ROMA-score assessment in improving the accuracy of frozen section histology in the diagnosis of borderline ovarian tumors (BOT). 113 women presenting with a unilateral ovarian mass diagnosed as serous/mucinous BOT at frozen-section-histology (FS) and/or confirmed on final pathology were recruited. Pathologists were informed of the results of preoperative clinical/instrumental assessment of all patients. For Group_A patients, additional information regarding He4, CA125, and ROMA score was available (in Group_B only CA125 was known). The comparison between Group A and Group B in terms of FS accuracy, demonstrated a consensual diagnosis in 62.8% versus 58.6% (P: n.s.), underdiagnosis in 25.6% versus 41.4% (P < 0.05), and overdiagnosis in 11.6% versus 0% (P < 0.01). Low FS diagnostic accuracy was associated with menopausal status (OR: 2.13), laparoscopic approach (OR: 2.18), mucinous histotype (OR: 2.23), low grading (OR: 1.30), and FIGO stage I (OR: 2.53). Ultrasound detection of papillae (OR: 0.29), septa (OR: 0.39), atypical vascularization (OR: 0.34), serum He4 assay (OR: 0.39), and ROMA score assessment (OR: 0.44) decreased the probability of underdiagnosis. A combined preoperative assessment through serum markers and ultrasonographic features may potentially reduce the risk of underdiagnosis of BOTs on FS while likely increasing the concomitant incidence of false-positive events. PMID:25431767

  15. Family Presence during Resuscitation: A Qualitative Analysis from a National Multicenter Randomized Clinical Trial

    PubMed Central

    De Stefano, Carla; Normand, Domitille; Jabre, Patricia; Azoulay, Elie; Kentish-Barnes, Nancy; Lapostolle, Frederic; Baubet, Thierry; Reuter, Paul-Georges; Javaud, Nicolas; Borron, Stephen W.; Vicaut, Eric; Adnet, Frederic

    2016-01-01

    Background The themes of qualitative assessments that characterize the experience of family members offered the choice of observing cardiopulmonary resuscitation (CPR) of a loved one have not been formally identified. Methods and Findings In the context of a multicenter randomized clinical trial offering family members the choice of observing CPR of a patient with sudden cardiac arrest, a qualitative analysis, with a sequential explanatory design, was conducted. The aim of the study was to understand family members’ experience during CPR. All participants were interviewed by phone at home three months after cardiac arrest. Saturation was reached after analysis of 30 interviews of a randomly selected sample of 75 family members included in the trial. Four themes were identified: 1- choosing to be actively involved in the resuscitation; 2- communication between the relative and the emergency care team; 3- perception of the reality of the death, promoting acceptance of the loss; 4- experience and reactions of the relatives who did or did not witness the CPR, describing their feelings. Twelve sub-themes further defining these four themes were identified. Transferability of our findings should take into account the country-specific medical system. Conclusions Family presence can help to ameliorate the pain of the death, through the feeling of having helped to support the patient during the passage from life to death and of having participated in this important moment. Our results showed the central role of communication between the family and the emergency care team in facilitating the acceptance of the reality of death. PMID:27253993

  16. Repeated Nipple Fluid Aspiration: Compliance and Feasibility Results from a Prospective Multicenter Study

    PubMed Central

    de Groot, J. S.; Moelans, C. B.; Elias, S. G.; Hennink, A.; Verolme, B.; Suijkerbuijk, K. P. M.; Jager, A.; Seynaeve, C.; Bos, P.; Witkamp, A. J.; Ausems, M. G. E. M.; van Diest, P. J.; van der Wall, E.

    2015-01-01

    Background Despite intensive surveillance, a high rate of interval malignancies is still seen in women at increased breast cancer risk. Therefore, novel screening modalities aiming at early detection remain needed. The intraductal approach offers the possibility to directly sample fluid containing cells, DNA and proteins from the mammary ductal system where, in the majority of cases, breast cancer originates. Fluid from the breast can non-invasively be obtained by oxytocin-assisted vacuum aspiration, called nipple fluid aspiration (NFA). The goal of this feasibility study was to evaluate the potential of repeated NFA, which is a critical and essential step to evaluate its possible value as a breast cancer screening method. Methods In this multicenter, prospective study, we annually collected nipple fluid for up to 5 consecutive years from women at increased breast cancer risk, and performed a questionnaire-based survey regarding discomfort of the aspiration. Endpoints of the current interim analyses were the feasibility and results of 994 NFA procedures in 451 women with total follow-up of 560 person years of observation. Results In this large group of women at increased risk of breast cancer, repetitive NFA appeared to be feasible and safe. In 66.4% of aspirated breasts, nipple fluid was successfully obtained. Independent predictive factors for successful NFA were premenopausal status, spontaneous nipple discharge, smaller breast size, bilateral oophorectomy and previous use of hormone replacement therapy or anti-hormonal treatment. The procedure was well tolerated with low discomfort. Drop-out rate was 20%, which was mainly due to repeated unsuccessful aspiration attempts. Only 1.6% of women prematurely declined further participation because of side effects. Conclusions Repeated NFA in women at increased breast cancer risk is feasible and safe. Therefore, NFA is a promising method to non-invasively obtain a valuable source of potential breast cancer specific

  17. SOD1 mutations in amyotrophic lateral sclerosis. Results from a multicenter Italian study.

    PubMed

    Battistini, Stefania; Giannini, Fabio; Greco, Giuseppe; Bibbò, Giuseppe; Ferrera, Loreta; Marini, Valeria; Causarano, Renzo; Casula, Michela; Lando, Giuliana; Patrosso, Maria Cristina; Caponnetto, Claudia; Origone, Paola; Marocchi, Alessandro; Del Corona, Alberto; Siciliano, Gabriele; Carrera, Paola; Mascia, Vincenzo; Giagheddu, Marcello; Carcassi, Carlo; Orrù, Sandro; Garrè, Cecilia; Penco, Silvana

    2005-07-01

    Amyotrophic Lateral Sclerosis (ALS), the most common form among motoneuron diseases, is characterized by a progressive neurodegenerative process involving motor neurons in the motor cortex, brain stem and spinal cord. Sporadic (SALS) accounts for the majority of patients but in about 10% of ALS cases the disease is inherited (FALS), usually as an autosomal dominant trait. In the present study we show the results of a referred based multicenter study on the distribution of SOD1 gene mutations in the largest cohort of Italian ALS patients described so far. Two hundred and sixty-four patients (39 FALS and 225 SALS) of Italian origin were studied. In 7 out of 39 FALS patients we found the following SOD1 gene mutations: i) a new G12R missense mutation in exon 1, found in a patient with a slowly progressive disease course; ii) the G41S mutation, in four unrelated patients with rapidly progressive course complicated with cognitive decline in two of them; iii) the L114F mutation, in a patient with a slowly progressive phenotype; iv) the D90A mutation, in a heterozygous patient with atypical phenotype. In addition, in one SALS patient a previously reported synonymous variant S59S was identified. In 17 (3 FALS and 14 SALS) out of 264 patients (6.4 %) the polymorphism A-->C at position 34 of intron 3 (IVS3: + 34 A-->C) was found, and in one FALS patient a novel variant IVS3 + 62 T-->C was identified. The frequency of SOD1 gene mutations (17.9 %) in FALS cases was comparable with that found in other surveys with a similar sample size of ALS cases. No SOD1 gene mutations have been identified in SALS cases. Within FALS cases, The most frequent mutation was the G41S identified in four FALS. PMID:15789135

  18. Blood Reference Intervals for Preterm Low-Birth-Weight Infants: A Multicenter Cohort Study in Japan.

    PubMed

    Ochiai, Masayuki; Matsushita, Yuki; Inoue, Hirosuke; Kusuda, Takeshi; Kang, Dongchon; Ichihara, Kiyoshi; Nakashima, Naoki; Ihara, Kenji; Ohga, Shouichi; Hara, Toshiro

    2016-01-01

    Preterm low-birth-weight infants remain difficult to manage based on adequate laboratory tests. The aim of this study was to establish blood reference intervals (RIs) in those newborns who were admitted to and survived in the neonatal intensive care unit (NICU). A multicenter prospective study was conducted among all infants admitted to 11 affiliated NICUs from 2010 to 2013. The clinical information and laboratory data were registered in a network database designed for this study. The RIs for 26 items were derived using the parametric method after applying the latent abnormal values exclusion method. The influence of birth weight (BW) and gestational age (GA) on the test results was expressed in terms of the standard deviation ratio (SDR), as SDRBW and SDRGA, respectively. A total of 3189 infants were admitted during the study period; 246 were excluded due to a lack of blood sampling data, and 234 were excluded for chromosomal abnormalities (n = 108), congenital anomalies requiring treatment with surgical procedures (n = 76), and death or transfer to another hospital (n = 50). As a result, 2709 infants were enrolled in this study. Both the SDRGA and SDRBW were above 0.4 in the test results for total protein (TP), albumin (ALB), alanine aminotransferase (ALT), and red blood cells (RBC); their values increased in proportion to the BW and GA. We derived 26 blood RIs for infants who were admitted to NICUs. These RIs should help in the performance of proper clinical assessments and research in the field of perinatal-neonatal medicine. PMID:27552225

  19. Nationwide Multicenter Reference Interval Study for 28 Common Biochemical Analytes in China

    PubMed Central

    Xia, Liangyu; Chen, Ming; Liu, Min; Tao, Zhihua; Li, Shijun; Wang, Liang; Cheng, Xinqi; Qin, Xuzhen; Han, Jianhua; Li, Pengchang; Hou, Li’an; Yu, Songlin; Ichihara, Kiyoshi; Qiu, Ling

    2016-01-01

    Abstract A nationwide multicenter study was conducted in the China to explore sources of variation of reference values and establish reference intervals for 28 common biochemical analytes, as a part of the International Federation of Clinical Chemistry and Laboratory Medicine, Committee on Reference Intervals and Decision Limits (IFCC/C-RIDL) global study on reference values. A total of 3148 apparently healthy volunteers were recruited in 6 cities covering a wide area in China. Blood samples were tested in 2 central laboratories using Beckman Coulter AU5800 chemistry analyzers. Certified reference materials and value-assigned serum panel were used for standardization of test results. Multiple regression analysis was performed to explore sources of variation. Need for partition of reference intervals was evaluated based on 3-level nested ANOVA. After secondary exclusion using the latent abnormal values exclusion method, reference intervals were derived by a parametric method using the modified Box–Cox formula. Test results of 20 analytes were made traceable to reference measurement procedures. By the ANOVA, significant sex-related and age-related differences were observed in 12 and 12 analytes, respectively. A small regional difference was observed in the results for albumin, glucose, and sodium. Multiple regression analysis revealed BMI-related changes in results of 9 analytes for man and 6 for woman. Reference intervals of 28 analytes were computed with 17 analytes partitioned by sex and/or age. In conclusion, reference intervals of 28 common chemistry analytes applicable to Chinese Han population were established by use of the latest methodology. Reference intervals of 20 analytes traceable to reference measurement procedures can be used as common reference intervals, whereas others can be used as the assay system-specific reference intervals in China. PMID:26945390

  20. Cytomegalovirus Infection following Kidney Transplantation: a Multicenter Study of 3065 Cases

    PubMed Central

    Einollahi, B.

    2012-01-01

    Background: Cytomegalovirus (CMV) infection is a common complication following kidney transplantation. Objective: To assess the incidence and risk factors of CMV infection among renal transplant recipients. Methods: In a retrospective multicenter study, 3065 renal transplant recipients from 17 transplant centers of Iran were studied between April 2008 and January 2011. Kidney transplant patients were routinely monitored by sequential blood samples drawn for use in the CMV-pp65 antigenemia assay, and for hematological and biochemistry tests. Results: 63% of studied patients were males; the mean±SD age of participants was 38±15 years. The majority of cases (81%) received a kidney from a living unrelated donor (LURD), 9% from living related donor (LRD), and 10% from deceased donors. 671 patients experienced CMV viremia. The incidence of CMV infection was 21.9% (95% CI: 20.4%–23.4%). The rate was higher in the first 6 months after transplantation (p<0.001); in recipients with higher level of cyclosporine (p<0.001); in those with lower hemoglobin concentration (p=0.02); patients with elevated ALT (p<0.001); those with increased fasting blood sugar (p=0.005); recipients with dyslipidemia (p<0.05); deceased kidney recipients (p=0.006); and patients with kidney graft impairment (p=0.01). In multivariate regression analysis, time since kidney transplantation (p<0.001) and renal allograft failure (p<0.001) were the only risk factors associated with CMV infection. Conclusions: CMV infection was a common complication in the first 6 months of kidney transplantation, particularly among patients with kidney graft impairment. PMID:25013626

  1. Medical students, spirituality and religiosity-results from the multicenter study SBRAME

    PubMed Central

    2013-01-01

    Background To evaluate the relationship between spirituality/religiosity (S/R) and the attitudes, beliefs and experiences of medical students in Brazil with respect to S/R in their undergraduate training and clinical practice. Methods SBRAME (Spirituality and Brazilian Medical Education) is a multicenter study involving 12 Brazilian medical schools with 5950 medical students (MS). Participants completed a questionnaire that collected information on socio-demographic data and S/R in their undergraduate training and practice. Results Of all MS, 3630 participated in the survey (61.0%). The sample was 53.8% women and the mean age was 22.5 years. The majority of MS believed that spirituality has an impact on patients’ health (71.2%) and that this impact was positive (68.2%). The majority also wanted to address S/R in their clinical practice (58.0%) and considered it relevant (75.3%), although nearly one-half (48.7%) felt unprepared to do so. Concerning their training, most MS reported that they had never participated in a “spirituality and health” activity (81.0%) and that their medical instructors had never or rarely addressed this issue (78.3%). The majority also believed that they should be prepared to address spiritual issues related to the health of their patients (61.6%) and that this content should be included in the medical curriculum (62.6%). Conclusion There is a large gap between MS attitudes and expectations and the S/R training that they are receiving during their undergraduate training. The majority of MS surveyed believe that patients should have their beliefs addressed and that these beliefs could have important effects on their health and the doctor-patient relationship. These results should stimulate discussion about the place that S/R training should have in the medical curriculum. PMID:24314327

  2. Blood Reference Intervals for Preterm Low-Birth-Weight Infants: A Multicenter Cohort Study in Japan

    PubMed Central

    Inoue, Hirosuke; Kusuda, Takeshi; Kang, Dongchon; Ichihara, Kiyoshi; Nakashima, Naoki; Ihara, Kenji; Ohga, Shouichi; Hara, Toshiro

    2016-01-01

    Preterm low-birth-weight infants remain difficult to manage based on adequate laboratory tests. The aim of this study was to establish blood reference intervals (RIs) in those newborns who were admitted to and survived in the neonatal intensive care unit (NICU). A multicenter prospective study was conducted among all infants admitted to 11 affiliated NICUs from 2010 to 2013. The clinical information and laboratory data were registered in a network database designed for this study. The RIs for 26 items were derived using the parametric method after applying the latent abnormal values exclusion method. The influence of birth weight (BW) and gestational age (GA) on the test results was expressed in terms of the standard deviation ratio (SDR), as SDRBW and SDRGA, respectively. A total of 3189 infants were admitted during the study period; 246 were excluded due to a lack of blood sampling data, and 234 were excluded for chromosomal abnormalities (n = 108), congenital anomalies requiring treatment with surgical procedures (n = 76), and death or transfer to another hospital (n = 50). As a result, 2709 infants were enrolled in this study. Both the SDRGA and SDRBW were above 0.4 in the test results for total protein (TP), albumin (ALB), alanine aminotransferase (ALT), and red blood cells (RBC); their values increased in proportion to the BW and GA. We derived 26 blood RIs for infants who were admitted to NICUs. These RIs should help in the performance of proper clinical assessments and research in the field of perinatal-neonatal medicine. PMID:27552225

  3. A Multicenter Evaluation of Blood Culture Practices, Contamination Rates, and the Distribution of Causative Bacteria

    PubMed Central

    Altindis, Mustafa; Koroglu, Mehmet; Demiray, Tayfur; Dal, Tuba; Ozdemir, Mehmet; Sengil, Ahmet Zeki; Atasoy, Ali Riza; Doğan, Metin; Cicek, Aysegul Copur; Ece, Gulfem; Kaya, Selcuk; Iraz, Meryem; Gultepe, Bilge Sumbul; Temiz, Hakan; Kandemir, Idris; Aksaray, Sebahat; Cetinkol, Yeliz; Sahin, Idris; Guducuoglu, Huseyin; Kilic, Abdullah; Kocoglu, Esra; Gulhan, Baris; Karabay, Oguz

    2016-01-01

    Background: The prognostic value of blood culture testing in the diagnosis of bacteremia is limited by contamination. Objectives: In this multicenter study, the aim was to evaluate the contamination rates of blood cultures as well as the parameters that affect the culture results. Materials and Methods: Sample collection practices and culture data obtained from 16 university/research hospitals were retrospectively evaluated. A total of 214,340 blood samples from 43,254 patients admitted to the centers in 2013 were included in this study. The blood culture results were evaluated based on the three phases of laboratory testing: the pre-analytic, the analytic, and the post-analytic phase. Results: Blood samples were obtained from the patients through either the peripheral venous route (64%) or an intravascular catheter (36%). Povidone-iodine (60%) or alcohol (40%) was applied to disinfect the skin. Of the 16 centers, 62.5% have no dedicated phlebotomy team, 68.7% employed a blood culture system, 86.7% conducted additional studies with pediatric bottles, and 43.7% with anaerobic bottles. One center maintained a blood culture quality control study. The average growth rate in the bottles of blood cultures during the defined period (1259 - 26,400/year) was 32.3%. Of the growing microorganisms, 67% were causative agents, while 33% were contaminants. The contamination rates of the centers ranged from 1% to 17%. The average growth time for the causative bacteria was 21.4 hours, while it was 36.3 hours for the contaminant bacteria. The most commonly isolated pathogens were Escherichia coli (22.45%) and coagulase-negative staphylococci (CoNS) (20.11%). Further, the most frequently identified contaminant bacteria were CoNS (44.04%). Conclusions: The high contamination rates were remarkable in this study. We suggest that the hospitals’ staff should be better trained in blood sample collection and processing. Sterile glove usage, alcohol usage for disinfection, the presence of

  4. Risk of miscarriage for pregnant users of pivmecillinam: a population-based case-control study.

    PubMed

    Nørgaard, Mette; Skriver, Mette Vinther; Sørensen, Henrik Toft; Schønheyder, Henrik Carl; Pedersen, Lars

    2008-04-01

    Few data exist on the risk of miscarriage after exposure to pivmecillinam. We therefore conducted a population-based case-control study in a Danish county with 0.5 million inhabitants during the period 1997-2002. We included 1,599 women with a miscarriage recorded in the Hospital Discharge Registry and selected 10 controls per case among primiparous women who had a live birth during the study period. Controls were selected from the Danish Medical Birth Registry. We obtained data on use of pivmecillinam and sulfamethizole from a prescription database. Five cases (0.30%) and 24 controls (0.15%) were exposed to pivmecillinam in the last week before the miscarriage/index date. After adjustment for maternal age, use of antidiabetics or antiepileptics, the odds ratio for miscarriages among users of pivmecillinam compared with non-users was 2.03 (95% confidence interval: 0.77-5.33) and the corresponding odds ratio for use of sulfamethizole was 1.53 (95% confidence interval: 0.76-3.09). Exposure within 2 to 12 weeks before the miscarriage was not associated with an increased risk. We concluded that use of pivmecillinam was associated with an increased risk of miscarriage, but the risk was not significantly (p=0.64) different from the risk associated with use of sulfamethizole. PMID:18397462

  5. Psychosocial Factors Associated with Polycystic Ovary Syndrome: a Case Control Study

    PubMed Central

    Sayyah-Melli, Manizheh; Alizadeh, Mahasti; Pourafkary, Nosratollah; Ouladsahebmadarek, Elaheh; Jafari-Shobeiri, Mehri; Abbassi, Jaleh; Kazemi-Shishvan, Maryam alsadat; Sedaghat, Kamran

    2015-01-01

    Introduction: Polycystic ovary syndrome (PCOS) is a disorder in women of reproductive age. Psychosocial factors can play a role in PCOS. Methods: To determine the psychosocial factors associated with PCOS in a case control study, 742 PCOS cases were compared to 798 women without PCOS for psychiatric disorders and social conditions. The data were collected using a validated questionnaire of the Minnesota Multiphasic Personality Inventory (MMPI). The Primary Care Evaluation of Mental Disorders. Patient Health Questionnaire (DSM-IV) was used to diagnose major psychopathological disorders and other depressive and anxiety syndromes. The suspected psychopathology was evaluated by a clinical psychiatrist. Results: There was a significant difference between cases and controls in education level (71.8% vs. 80.4%; (P<0.001), and employment status (60% vs. 53%; P=0.01) (respectively). Chronic anxiety (35.7% vs. 26.8%; P<0.001), depression (18.9% vs. 7.9 %; P<0.001), anxiety disorders (7.7% vs. 3.3%; P<0.001), and personality disorders (2.9% vs. 1.7%; P=0.01), were higher in the PCOS patients compared controls, respectively. Conclusion: The results showed that chronic anxiety and depression were the most pscycologic pattern in PCO patients. Lower educational level and unemployment were higher in the cases than controls. PMID:26464839

  6. A matched case control study of risk indicators of breast cancer in assam, India.

    PubMed

    Rajbongshi, N; Mahanta, L B; Nath, D C; Sarma, J D

    2015-04-01

    Breast cancer is the leading cause of cancer death among women worldwide especially in a developing country like India. It also occupies the highest place with relative proportion 17.5% in the Hospital Based Cancer Registry in progress in the Dr. B. Borooah Cancer Research Institute. Dr. B. Borooah Cancer Research Institute is the Regional Cancer Care Center for entire North East region of India. With this background a matched case control study of 100 cases of breast cancer and 100 controls was carried out to investigate the role of different Socio economic, Female Reproductive and Life style related factors and to understand the etiology of breast cancer in Assam. Controls are matched to the cases by age at diagnosis (±5 years), family income and place of residence with matching ratio 1:1. Data were collected using questionnaire and then conditional logistic regression analysis is used to estimate the odd ratios for several factors. Study revealed that breast cancer occurrence has statistical association with the factors chewing habits (p=0.003), number of children (p=0.080), age at marriage (p=0.014), age at first child birth (p=0.007), age at menarche (p=0.010). PMID:26007270

  7. 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. PMID:3834338

  8. Childhood leukemia and parental occupation: a register-based case-control study

    SciTech Connect

    Van Steensel-Moll, H.A.; Valkenburg, H.A.; Van Zanen, G.E.

    1985-02-01

    To explore possible etiologic factors of childhood leukemia, a case-control study was performed in the Netherlands. Cases were selected from a complete nationwide register of cases of childhood leukemia which were diagnosed between 1973 and 1980. Controls were matched with cases for year of birth, sex, and place of residence at the time of diagnosis. Information about possible exposure was collected by a postal questionnaire addressed to the parents. This report concerns the results of the analysis of parental occupations and occupational exposures for 519 children with acute lymphocytic leukemia and 507 controls. During pregnancy, more mothers of patients were working in ''hydrocarbon-related'' occupations; relative risk (RR) = 2.5 (95% confidence interval (CI) = 0.7 - 9.4). Likewise, greater occupational exposure to chemicals (paint, petroleum products, and unspecified chemicals) during pregnancy was found for mothers of patients (RR = 2.4, 95% CI = 1.2 - 4.6). The kind of work being performed by the mothers one year before diagnosis did not differ between cases and controls. For the fathers, no relationship was found between a hydrocarbon-related occupation or occupational exposure to chemicals and leukemia in the offspring. Adjustment for birth order, social class, and degree of urbanization did not materially change the relative risks. 16 references, 5 tables.

  9. 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.

  10. Cohort and case-control analyses of workers exposed to vinyl chloride: An update

    SciTech Connect

    Wu, W.A.; Steenland, K.; Brown, D.; Wells, V.; Jones, J.; Schulte, P.; Halperin, W.

    1989-06-01

    The mortality in a cohort of workers at a vinyl chloride polymerization plant has been updated, extending the period of observation in the original study from 1974 to 1986. Workers at this plant may have been exposed to vinyl chloride monomer and/or polyvinyl chloride dust, or may have had no exposure to either substance. Seventy-six percent of the work force worked in jobs with potential exposure to vinyl chloride monomer. Among the total cohort, statistically significant excess risks were observed for liver, lung, and brain cancer. For the subcohort of workers exposed to vinyl chloride monomer, the standardized mortality ratio (SMR) for liver cancer was 333 (90% confidence interval (CI) 202 to 521). However, there were no significant excesses of either brain (SMR = 145, 90% CI 78 to 249) or lung cancer (SMR = 115, 90% CI 96 to 141). To investigate dose response, nested case-control studies for liver, brain, and lung cancer were conducted among the total cohort (including the nonexposed). For these studies there were two exposure variables, cumulative dose of vinyl chloride monomer and cumulative dose of polyvinyl chloride dust. Cumulative dose was defined as the product of level and duration of exposure. The only significant association between disease risk and cumulative dose was for liver cancer and cumulative dose of vinyl chloride monomer. Further division of the liver cancers into angiosarcoma (n = 12) and other liver cancers (n = 7), based on review of death certificates and medical records, showed that the dose response existed only for angiosarcomas.

  11. Urinary strontium and the risk of breast cancer: A case-control study in Guangzhou, China

    SciTech Connect

    Chen, Li-Juan; Tang, Lu-Ying; He, Jian-Rong; Su, Yi; Cen, Yu-Ling; Yu, Dan-Dan; Wu, Bang-Hua; Lin, Ying; Chen, Wei-Qing; Song, Er-Wei; Ren, Ze-Fang

    2012-01-15

    Strontium has been widely used in industries like electronic and pharmacy. It has a carcinogenic potential, however, and no study has been conducted to evaluate its effects on cancer risk. The aim of this study was to explore the possible association between strontium and breast cancer risk in a case-control study including 240 incident invasive breast cancer patients and 246 age-matched controls. We measured the urinary concentrations of strontium by inductively coupled plasma mass spectrometry, and conducted face-to-face interviews to obtain information on potential breast cancer risk factors. Multivariable analysis was used to estimate the association. Creatinine-adjusted levels [median (25th, 75th) {mu}g/g] of strontium were 155.59 (99.05, 230.70) in the breast cancer patients and 119.62 (81.97, 163.76) in the controls. Women in the highest tertile of strontium showed 124% increased risk of breast cancer, when compared with those in the lowest tertile after adjustment for the potential risk factors [OR (95% CI): 2.24 (1.42-3.81)]. This association was particularly strong for HER2 positive breast cancer [OR (95% CI): 10.92 (3.53-33.77)], and only occurred among premenopausal women. These results suggest a potential role of strontium in the development of breast cancer and urge further studies on the environmental contamination and the physiological and pathological mechanisms of strontium.

  12. A melanoma case-control study at the Los Alamos National Laboratory.

    PubMed

    Acquavella, J F; Wilkinson, G S; Tietjen, G L; Key, C R; Stebbings, J H; Voelz, G L

    1983-09-01

    We conducted a melanoma case-control study at the Los Alamos National Laboratory to investigate whether related occupational exposures or personal characteristics of employees could be identified. This study was prompted by a recent report from the Lawrence Livermore National Laboratory that melanoma was much more frequent than expected among employees and that persons suffering from melanoma more often worked as chemists. Our investigation did not uncover an association with plutonium body burden, cumulative external radiation exposure, or employment as a chemist or a physicist. The major finding was that cases were more educated than controls. Melanoma risk was 2.11 among college-educated employees and increased to 3.17 among those with graduate degrees (Mantel-extension linear trend probability = 0.038). This finding is consistent with the often reported increased melanoma incidence among persons of higher social class. It points to personal characteristics, particular to persons of higher educational attainment, as risk factors for melanoma at the Los Alamos National Laboratory. PMID:6885467

  13. Western dietary pattern is related to premenstrual syndrome: a case-control study.

    PubMed

    Farasati, Negin; Siassi, Fereydoun; Koohdani, Fariba; Qorbani, Mostafa; Abashzadeh, Karolin; Sotoudeh, Gity

    2015-12-28

    Although premenstrual syndrome (PMS) affects a large number of women of reproductive age, the aetiology of this disorder has not yet been fully elucidated. The relationship between food intake and PMS morbidity has been investigated in several studies, but dietary patterns of PMS patients have not been taken into consideration up to now. We examined dietary patterns of 320 nurses with (n 160) and without (n 160) PMS in a case-control study. Food intakes over the past year were determined using semi-quantitative FFQ. Factor analysis was used to identify the main dietary patterns, and logistic regression was used to model the relationship between dietary patterns and PMS morbidity. Three dietary patterns were identified in the analysis: healthy, Western and traditional. After adjustment for age, BMI, menstrual cycles, physical activity and energy intake, participants in the second (OR 2·53; 95 % CI 1·18, 5·43) and third (OR 4·39; 95 % CI 1·97, 9·81) quintiles of the Western dietary pattern were more likely to experience PMS compared with those in the first quintile. The study findings therefore reveal that Western dietary pattern might be associated with PMS morbidity. However, this result should be interpreted with caution as there was no evidence of a dose-response relationship. Future studies are needed to confirm our findings in other populations. PMID:26459000

  14. Probiotic Beverage with Soy Isoflavone Consumption for Breast Cancer Prevention: A Case-control Study.

    PubMed

    Toi, Masakazu; Hirota, Saya; Tomotaki, Ai; Sato, Nobuaki; Hozumi, Yasuo; Anan, Keisei; Nagashima, Takeshi; Tokuda, Yutaka; Masuda, Norikazu; Ohsumi, Shozo; Ohno, Shinji; Takahashi, Masato; Hayashi, Hironori; Yamamoto, Seiichiro; Ohashi, Yasuo

    2013-08-01

    The purpose of this study is to evaluate how beverages containing Lactobacillus casei Shirota (BLS) and soy isoflavone consumption since adolescence affected the incidence of breast cancer. In a population-based case-control study, three hundred and six cases with breast cancer and 662 controls aged 40 to 55 were matched for age and residential area and included in the analyses. Diet, lifestyle and other breast cancer risk factors were investigated using the self-administered questionnaire and interview. Odds ratios (ORs) of BLS and soy isoflavone consumption for breast cancer incidence were independently and jointly estimated using a conditional logistic regression. The ORs of BLS consumption (≥ four times a week against < four times a week) was 0.65 and statistically significant (p = 0.048). The analysis of association between soy consumption and breast cancer incidence showed the more the isoflavone consumption is, the lower the odds of breast cancer becomes. Adjusted ORs for breast cancer in the second, the third and the fourth quartiles of soy consumption against the first quartile were 0.76, 0.53 and 0.48, respectively (trend test, p = 0.0002). The BLS-isoflavone interaction was not statistically significant; however, a biological interaction was suggested. Regular consumption of BLS and isoflavones since adolescence was inversely associated with the incidence of breast cancer in Japanese women. PMID:23966890

  15. Hormonal risk factors for ovarian cancer in the Albanian case-control study.

    PubMed

    Pajenga, Edlira; Rexha, Tefta; Çeliku, Silva; Bejtja, Gazmend; Pisha, Mimoza

    2013-05-01

    The role of reproductive factors in the aetiology of ovarian cancer had been evaluated in hospital-based case-control study conducted in Albania, providing a total dataset of 283 cases and 1019 controls. Logistic regression models were used to obtain relative risk (OR) estimates. The present results showed that parity had protective effects which increased until the forth birth and the trend in risk was significant (p < 0.01). In each stratum and overall, nulliparous women appeared to be at highly increased risk compared to those who had different number of births (OR=12.5, 95%, CI: 2.4-63.8). Evaluation of early age at menarche and late age at menopause, showed statistically significant increased risk. Furthermore, increased risk was observed between pre-menopausal women and never-married nulliparity women, respectively (OR=1.44 95%, CI: 0.88-2.36; OR=8.98, 95%, CI: 1.44 - 56.14), but ovarian cancer risk was reduced for hysterectomized women. These findings suggest that Albanian women have risk factors similar to women in western countries. PMID:23725504

  16. Hormonal risk factors for ovarian cancer in the Albanian case-control study

    PubMed Central

    Pajenga, Edlira; Rexha, Tefta; Çeliku, Silva; Bejtja, Gazmend; Pisha, Mimoza

    2013-01-01

    The role of reproductive factors in the aetiology of ovarian cancer had been evaluated in hospital-based case-control study conducted in Albania, providing a total dataset of 283 cases and 1019 controls. Logistic regression models were used to obtain relative risk (OR) estimates. The present results showed that parity had protective effects which increased until the forth birth and the trend in risk was significant (p < 0.01). In each stratum and overall, nulliparous women appeared to be at highly increased risk compared to those who had different number of births (OR=12.5, 95%, CI: 2.4-63.8). Evaluation of early age at menarche and late age at menopause, showed statistically significant increased risk. Furthermore, increased risk was observed between pre-menopausal women and never-married nulliparity women, respectively (OR=1.44 95%, CI: 0.88-2.36; OR=8.98, 95%, CI: 1.44 - 56.14), but ovarian cancer risk was reduced for hysterectomized women. These findings suggest that Albanian women have risk factors similar to women in western countries. PMID:23725504

  17. A case-control study on fat-to-muscle ratio and risk of breast cancer.

    PubMed

    Ronco, Alvaro L; Boeing, Heiner; De Stefani, Eduardo; Schulz, Mandy; Schulze, Matthias; Pischon, Tobias

    2009-01-01

    Our objective was to analyze detailed anthropometric characterization for risk of breast cancer in Uruguayan women. The design was a case-control study. The setting was Pereira Rossell Women's Hospital, Montevideo, Uruguay. Subjects were 343 incident breast cancer cases and 1,042 frequency-matched healthy controls who were interviewed on menstrual and reproductive story; and a series of skin folds, circumferences, and diameters were measured to calculate fat and muscle fractions and the derived fat-to-muscle ratio (FMR). Odds ratio (ORs) coefficients were taken as estimates of relative risk derived from unconditional logistic regression. Muscle fraction was negatively associated with risk [OR for highest quartile = 0.23, 95% confidence interval (CI) = 0.15-0.34], fat fraction was positively associated (OR = 3.90, 95% CI = 2.62-5.80), and FMR was positively associated (OR = 4.45, 95% CI = 2.99-6.62). Stratified analyses by body mass index levels also showed risk increases for the highest tertiles of FMR, always displaying significant linear trends. Since increases of risk were found in overweight and in normal weight women, results suggest that fractions and amount of muscle and fat components might be risk factors for breast cancer on the basis of currently existing metabolic and immune interrelationships between adipose and muscular tissue given by glutamine, exercise-derived myokines, and other cytokines produced by these tissues. PMID:19838918

  18. Risk factors associated with death in Brazilian children with severe dengue: a case-control study

    PubMed Central

    dos Remédios Freitas Carvalho Branco, Maria; de Albuquerque Luna, Expedito José; Júnior, Leônidas Lopes Braga; de Oliveira, Ricardo Villar Barbosa; Rios, Lívia Teresa Moreira; do Socorro da Silva, Maria; Medeiros, Maria Nilza Lima; Silva, Gilnara Fontinelle; Nina, Fernanda Campos Amaral Figueiredo; Lima, Taliane Jardim; Brito, Jayron Alves; de Oliveira, Avessandra Costa Cardoso; Pannuti, Claudio Sergio

    2014-01-01

    OBJECTIVE: The purpose of this case-control study was to evaluate risk factors associated with death in children with severe dengue. METHODS: The clinical condition of hospitalized patients with severe dengue who died (cases, n = 18) was compared with that of hospitalized patients with severe dengue who survived (controls, n = 77). The inclusion criteria for this study were age under 13 years; hospital admission in São Luis, northeastern Brazil; and laboratory-confirmed diagnosis of dengue. RESULTS: Severe bleeding (hemoptysis), a defining criterion for dengue severity, was the factor most strongly associated with death in our study. We also found that epistaxis and persistent vomiting, both included as warning signs in the World Health Organization (WHO) classification of dengue, were strongly associated with death. No significant association was observed between any of the laboratory findings and death. CONCLUSIONS: The finding that epistaxis and persistent vomiting were also associated with death in children with severe dengue was unexpected and deserves to be explored in future studies. Because intensive care units are often limited in resource-poor settings, any information that can help to distinguish patients with severe dengue with a higher risk to progress to death may be crucial. PMID:24473560

  19. 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

  20. A Case-Control Study of Risk Factors Associated with Scrub Typhus Infection in Beijing, China

    PubMed Central

    Zhang, Liqin; Dou, Xiangfeng; Wang, Xiaomei; Li, Weihong; Zhang, Xiuchun; Sun, Yulan; Guan, Zengzhi; Li, Xinyu; Wang, Quanyi

    2013-01-01

    To investigate the risk factors of scrub typhus infection in Beijing, China, a case-control study was carried out. Cases (n = 56) were defined as persons who were diagnosed by PCR and serological method within three years. Three neighborhood control subjects were selected by matching for age and occupation. Living at the edge of the village, living in the houses near grassland, vegetable field or ditch, house yard without cement floor, piling weeds in the house or yard, all of these were risk factors for scrub typhus infection. Working in vegetable fields and hilly areas, and harvesting in autumn posed the highest risks, with odds ratios (ORs) and 95% confidence intervals (CIs) of 3.7 (1.1–11.9), 8.2 (1.4–49.5), and 17.2 (5.1–57.9), respectively. These results would be useful for the establishment of a detail control strategy for scrub typhus infection in Beijing, China. PMID:23691083

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

    PubMed Central

    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; Schäfer, 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; 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 genomewide association studies (GWAS) are needed. Method We used case-control analyses of 896 cases with DSM-IV ADHD genotyped using the Affymetrix 5.0 array and 2,455 repository controls screened for psychotic and bipolar symptoms genotyped using Affymetrix 6.0 arrays. A consensus SNP set was imputed using BEAGLE 3.0, resulting in an analysis dataset of 1,033,244 SNPs. The data were analyzed using a generalized linear model. Results No genome-wide significant associations were found. The most significant results implicated the following genes: PRKG1, FLNC, TCERG1L, PPM1H, NXPH1, PPM1H, CDH13, HK1 and HKDC1. Conclusions The current analyses are a useful addition to the present literature and will make a valuable contribution to future meta-analyses. The candidate gene findings are consistent with a prior meta-analysis in suggesting that the effects of ADHD risk variants must, individually, be very small and/or include multiple rare alleles. PMID:20732627

  2. A Case Control Study on Risk Factors Associated with Low Birth Weight Babies in Eastern Nepal

    PubMed Central

    Bhaskar, Ravi Kumar; Deo, Krishna Kumar; Neupane, Uttam; Chaudhary Bhaskar, Subhadra; Yadav, Birendra Kumar; Pokharel, Hanoon P.; Pokharel, Paras Kumar

    2015-01-01

    Background. This study was done to assess the maternal and sociodemographic factors associated with low birth weight (LBW) babies. Methods. An unmatched case control study was done involving 159 cases (mothers having LBW singleton babies) and 159 controls (mothers having normal birth weight singleton babies). Results. More than 50% of LBW babies were from the mothers with height ≤145 cm while only 9.43% of NBW babies were from the mothers with that height. Finally, after multivariate logistic regression analysis, maternal height, time of first antenatal care (ANC) visit, number of ANC visits, iron supplementation, calcium supplementation, maternal education, any illness during pregnancy, and hypertension were found as the significant predictors of LBW. However, maternal blood group AB, normal maternal Body Mass Index (BMI), mother's age of 30 or more years, and starting ANC visit earlier were found to be protective for LBW. Conclusion. Study findings suggest that selectively targeted interventions such as delay age at first pregnancy, improving maternal education and nutrition, and iron and calcium supplementation can prevent LBW in Nepal. PMID:26783406

  3. Risk factors for preterm birth: a case-control study in rural area of western China

    PubMed Central

    Zhang, Xiaosong; Zhou, Min; Chen, Lijun; Hao, Bo; Zhao, Gengli

    2015-01-01

    Preterm birth is the leading cause of perinatal morbidity and mortality in China, the study is to learn risk factors for preterm birth in rural area of western China. A 1:1 case-control study in which cases included the pregnant women of preterm birth and controls included the matched pregnant women of normal deliver was conducted in 5 counties in western China. Data about the general situation, pregnancy history, reproductive health infection (RTI) symptoms, pregnancy complications, et al were obtained by using questionnaire. The results showed that the risk factors related to preterm birth were including: family income, mother’s age ≥ 35 years old, antennal visiting ≤ 4 times, low education level, preterm birth history, abnormal vaginal discharge, pregnancy complications. The logistic regression analysis showed that only 3 factors of preterm birth were left at the last step, which of antenatal visiting ≤ 4 times, PROM and placenta previa had significant difference. We show that family income, age, antennal visiting, low education level, preterm birth history, abnormal vaginal discharge, pregnancy complications are the risk factors of preterm birth. PMID:26064379

  4. Autonomic nervous tone in vitiligo patients--a case-control study.

    PubMed

    Trapp, Eva-Maria; Trapp, Michael; Sampogna, Francesca; Rohrer, Peter Michael; Egger, Josef Wilhelm; Wolf, Peter; Kapfhammer, Hans-Peter; Linder, Michael Dennis; Richtig, Erika; Baulmann, Johannes; Hofer, Angelika

    2015-02-01

    In this cross-sectional, exploratory case-control study the vegetative arousal in vitiligo patients compared to an age and gender matched healthy control group was assessed. Forty-eight participants (24 outpatients with generalised vitiligo and 24 healthy controls) completed a test procedure consisting of an initial period of rest (R1), a defined mental stress task (the d2 test of attention), a second period of rest (R2) followed by an individually, age adapted physical stress task (bicycle ergometry) and a final period of rest (R3). Based on a continuously recorded electrocardiogram, heart rate variability, in particular high frequency (HF) and low frequency (LF) components were determined. Within the 3 periods of rest, vitiligo patients showed a higher vegetative arousal than controls, represented by the ratio of LF/HF which mirrors the sympatho-vagal balance (R1: p = 0.027; R2: p = 0.003; R3: p = 0.029). No differences between the 2 groups were found during the mental (p = 0.187) and the physical stress task (p = 0.773). The results suggest a higher vegetative arousal in vitiligo patients. PMID:24820126

  5. Occupational risk factors for brain cancer: a population-based case-control study in Iowa.

    PubMed

    Zheng, T; Cantor, K P; Zhang, Y; Keim, S; Lynch, C F

    2001-04-01

    A number of occupations and industries have been inconsistently associated with the risk of brain cancer. To further explore possible relationships, we conducted a population-based case-control study of brain glioma in the state of Iowa, involving 375 histologically confirmed incident cases and 2434 population-based controls. Among men, the industries and/or occupations that had a significantly increased risk for employment of more than 10 years included roofing, siding, and sheet metalworking; newspaper work; rubber and plastics products, particularly tires and inner tubes; miscellaneous manufacturing industries; wholesale trade of durable goods, grain, and field beans; cleaning and building service occupations; miscellaneous mechanics and repairers; and janitors and cleaners. Subjects who worked in plumbing, heating, and air conditioning; electrical services; gasoline service stations; and military occupations also experienced a significantly increased risk. Among women, significant excess risk was observed for occupations in agricultural services and farming, apparel and textile products, electrical and electronic equipment manufacturing, various retail sales, record-keeping, and restaurant service. Workers in industries with a potential for gasoline or motor exhaust exposures experienced a non-significant excess risk of brain glioma. PMID:11322092

  6. 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. PMID:26787570

  7. Juvenile perpetrators of homicides and attempted homicides--a case control study.

    PubMed

    Britvić, Dolores; Urlić, Ivan; Definis-Gojanović, Marija

    2006-03-01

    The aim of this study was to explore the influence of certain aspects of family dynamics, as well as some behavior and psychological development disorders on the occurrence of homicides and attempted homicides among juveniles in the Split Dalmatian County over a period of 10 years (1989-1998). A retrospective case-control study was performed to compare juvenile murderers and attempted murderers with minors who committed other offences, i.e. property crimes. The subjects were paired according to demographic and socio-economic background. The data obtained from County Court's files included social anamnesis, specialists' observation and psychiatric expertise results. There was a significant difference between the study group and their controls in the frequency of physical violence and parental rejection during childhood. Neuropsychological and neurophysiological abnormalities were more frequent in the experimental than in the control group. Stealing occurred more often in the control group. No significant differences were found for other studied risk factors. There is no unique type of juvenile murderer. A juvenile homicide is committed under the influence of various developmental characteristics, family milieu, and constitution combined with environmental factors and perpetrator's perception of the victim. PMID:16617589

  8. 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

  9. Matching for Several Sparse Nominal Variables in a Case-Control Study of Readmission Following Surgery

    PubMed Central

    Zubizarreta, José R.; Reinke, Caroline E.; Kelz, Rachel R.; Silber, Jeffrey H.; Rosenbaum, Paul R.

    2014-01-01

    Matching for several nominal covariates with many levels has usually been thought to be difficult because these covariates combine to form an enormous number of interaction categories with few if any people in most such categories. Moreover, because nominal variables are not ordered, there is often no notion of a “close substitute” when an exact match is unavailable. In a case-control study of the risk factors for read-mission within 30 days of surgery in the Medicare population, we wished to match for 47 hospitals, 15 surgical procedures grouped or nested within 5 procedure groups, two genders, or 47 × 15 × 2 = 1410 categories. In addition, we wished to match as closely as possible for the continuous variable age (65–80 years). There were 1380 readmitted patients or cases. A fractional factorial experiment may balance main effects and low-order interactions without achieving balance for high-order interactions. In an analogous fashion, we balance certain main effects and low-order interactions among the covariates; moreover, we use as many exactly matched pairs as possible. This is done by creating a match that is exact for several variables, with a close match for age, and both a “near-exact match” and a “finely balanced match” for another nominal variable, in this case a 47 × 5 = 235 category variable representing the interaction of the 47 hospitals and the five surgical procedure groups. The method is easily implemented in R. PMID:25418991

  10. Assessing individual sow risk factors for coliform mastitis: a case-control study.

    PubMed

    Gerjets, Imke; Traulsen, Imke; Reiners, Kerstin; Kemper, Nicole

    2011-07-01

    In order to investigate sow-specific risk factors associated with coliform mastitis, a case-control study was performed over the course of 28 months. Data of three farms were collected under production conditions. Sows suffering from coliform mastitis after farrowing served as cases, and healthy half- or full-sib sows from the same farm served as controls. Individual sow characteristics and the seasonal influence were analysed by conditional logistic regression. The final multivariate model identified four risk factors: the risk of suffering from coliform mastitis increased with a higher number of piglets born alive and stillborn piglets. Gilts had an increased risk for the disease, and birth intervention was also associated with a higher prevalence of mastitis. Birth induction and season had no significant influence on the occurrence of coliform mastitis. The time during and soon after farrowing is a very sensitive period in pig production demanding great attention by the farmer. With respect to the economic losses, monitoring of potentially endangered sows as well as detailed documentation and selection of disease cases are of particular importance when coping with coliform mastitis. PMID:21570140

  11. Risk factors for basal cell carcinoma in the UK: case-control study in 806 patients.

    PubMed Central

    Lear, J T; Tan, B B; Smith, A G; Bowers, W; Jones, P W; Heagerty, A H; Strange, R C; Fryer, A A

    1997-01-01

    Basal cell carcinoma (BCC) is the commonest malignant neoplasm in white people. We present a large UK case-control study in which conditional logistic regression analysis of age-matched and gender-matched data sets was used to compare, first, cases with controls (n = 403) and second, patients having multiple BCC with those having a single BCC (n = 278). Eye/hair colour, occupation, skin type, social class, tumour site at presentation and smoking history were assessed. Social class 1/2, skin type 1, red/blonde hair and blue/green eyes were all related to BCC risk, social class most strongly (odds ratio 2.36, P = 0.007). Truncal site at presentation was a risk factor for the development of multiple BCC (odds ratio 4.03, P = 0.002). These data support the view that genetically mediated differences in ultraviolet responsiveness are important in BCC, though the scale of their effect is small. They may be exploitable in primary and secondary prevention as well as giving insights into pathogenesis. In particular, the fact that patients presenting with a truncal tumour are at increased risk of further BCC suggests that intermittent exposure in genetically predisposed individuals may contribute to a cancer susceptibility syndrome. PMID:9290417

  12. 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] . PMID:24992005

  13. 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

  14. 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

  15. Risk factors for human alveolar echinococcosis: a case-control study in Hokkaido, Japan.

    PubMed

    Yamamoto, N; Kishi, R; Katakura, Y; Miyake, H

    2001-10-01

    A case-control study to determine the risk factors for human alveolar echinococcosis (AE) was conducted in Hokkaido, Japan. The 134 cases were either patients clinically diagnosed as having AE (N =61) or other individuals found to be seropositive for Echinococcus multilocularis although showing no abnormalities in ultrasound scans (N = 73). Two groups of case-matched controls were employed: one of 670 individuals selected from a list of residents of Hokkaido (group A) and the other of 650 subjects selected from a list of individuals who had been found seronegative in earlier investigations (group B). Because of the long latency of AE, potential risk factors were studied over two different periods: for the 0-10 and 11-20 years before the year of diagnosis/recorded seropositivity. The results of multivariate analyses, in which the cases were compared with each control group, indicated that the rearing of cattle and pigs and the use of well water were significant risk factors and that the use of tap water significantly decreased the risk of an individual having AE. Extension of the piped water supply and health education on improving the disposal of household rubbish (to keep foxes away from houses) should help reduce the risk of AE infection in the study area. PMID:11784422

  16. 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

  17. 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

  18. A case-control study of leukemia at a naval nuclear shipyard.

    PubMed

    Stern, F B; Waxweiler, R A; Beaumont, J J; Lee, S T; Rinsky, R A; Zumwalde, R D; Halperin, W E; Bierbaum, P J; Landrigan, P J; Murray, W E

    1986-06-01

    A matched case-control study was conducted of 53 leukemia deaths and of 212 controls within a previously studied cohort of 24,545 on-shore workers employed between January 1, 1952 and August 15, 1977 at the Portsmouth (New Hampshire) Naval Shipyard. The study sought to ascertain a priori whether there was an association between leukemia deaths and occupational exposure to either ionizing radiation or organic solvents. To obtain information on individual exposures, radiation dose histories and detailed work histories by job and shop were evaluated for each subject. No statistically significant associations were found either between ionizing radiation or presumed solvent exposure and myelogenous or lymphatic leukemia. However, when specific job categories and shops were examined without benefit of a priori hypotheses, two occupations, electrician and welder, were found to be associated with leukemia. For electricians, the Mantel-Haenszel odds ratio (ORMH) was significantly elevated for all leukemias (ORMH = 3.00, 95% confidence interval (CI) = 1.29-6.98), particularly for lymphatic leukemia (ORMH = 6.00, 95% CI = 1.47-24.45). For welders, the odds ratio was not significantly elevated for all leukemias (ORMH = 2.25, 95% CI = 0.92-5.53), but was significantly elevated for myeloid leukemia (ORMH = 3.83, 95% CI = 1.28-11.46). These findings persisted when potential confounders were adjusted by means of a conditional logistic regression model. PMID:3458360

  19. 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

  20. Melanoma and occupation: results of a case-control study in The Netherlands.

    PubMed

    Nelemans, P J; Scholte, R; Groenendal, H; Kiemeney, L A; Rampen, F H; Ruiter, D J; Verbeek, A L

    1993-07-01

    Several studies have reported excesses of risk of melanoma in specific industries. Data from a case-control study in The Netherlands, including 140 cases with a cutaneous melanoma and 181 controls with other types of malignancy, were used to evaluate whether the reported associations with these specific industries could be reproduced. Adjustment for characteristics of pigmentation and exposure to sunlight was made. Increased risks of cutaneous melanoma were found for subjects who had ever worked in the electronics industry (odds ratio (OR) = 2.03, 95% confidence interval (95% CI) 0.63-6.62), in the metal industry (OR = 2.61, 95% CI 0.96-7.10), and in the transport and communication branch (OR = 1.92, 95% CI 0.84-4.35). These ORs were adjusted for age, sex, education, hair colour, tendency to burn, freckling, and exposure to sunlight. No increased risks were seen for workers in the chemical industry, the textile industry, and among health care workers. Analyses according to duration and latency of exposure did not give consistent results, but existing patterns may be obscured by the imprecision of the estimates. PMID:8343426

  1. A Shrinkage Method for Testing the Hardy-Weinberg Equilibrium in Case-Control Studies

    PubMed Central

    Zang, Yong; Yuan, Ying

    2014-01-01

    Testing for the Hardy-Weinberg equilibrium (HWE) is often used as an initial step for checking the quality of genotyping. When testing the HWE for case-control data, the impact of a potential genetic association between the marker and the disease must be controlled for otherwise the results may be biased. Li and Li (2008) proposed a likelihood ratio test (LRT) that accounts for this potential genetic association and it is more powerful than the commonly used control-only χ2 test. However, the LRT is not efficient when the marker is independent of the disease, and also requires numerical optimization to calculate the test statistic. In this article, we propose a novel shrinkage test for assessing the HWE. The proposed shrinkage test yields higher statistical power than the LRT when the marker is independent of or weakly associated with the disease, and converges to the LRT when the marker is strongly associated with the disease. In addition, the proposed shrinkage test has a closed form and can be easily used to test the HWE for large datasets that result from genome-wide association studies. We compare the performance of the shrinkage test with existing methods using simulation studies, and apply the shrinkage test to a genome-wide association dataset for Alzheimer’s disease. PMID:23934751

  2. Urinary strontium and the risk of breast cancer: a case-control study in Guangzhou, China.

    PubMed

    Chen, Li-Juan; Tang, Lu-Ying; He, Jian-Rong; Su, Yi; Cen, Yu-Ling; Yu, Dan-Dan; Wu, Bang-Hua; Lin, Ying; Chen, Wei-Qing; Song, Er-Wei; Ren, Ze-Fang

    2012-01-01

    Strontium has been widely used in industries like electronic and pharmacy. It has a carcinogenic potential, however, and no study has been conducted to evaluate its effects on cancer risk. The aim of this study was to explore the possible association between strontium and breast cancer risk in a case-control study including 240 incident invasive breast cancer patients and 246 age-matched controls. We measured the urinary concentrations of strontium by inductively coupled plasma mass spectrometry, and conducted face-to-face interviews to obtain information on potential breast cancer risk factors. Multivariable analysis was used to estimate the association. Creatinine-adjusted levels [median (25th, 75th) μg/g] of strontium were 155.59 (99.05, 230.70) in the breast cancer patients and 119.62 (81.97, 163.76) in the controls. Women in the highest tertile of strontium showed 124% increased risk of breast cancer, when compared with those in the lowest tertile after adjustment for the potential risk factors [OR (95% CI): 2.24 (1.42-3.81)]. This association was particularly strong for HER2 positive breast cancer [OR (95% CI): 10.92 (3.53-33.77)], and only occurred among premenopausal women. These results suggest a potential role of strontium in the development of breast cancer and urge further studies on the environmental contamination and the physiological and pathological mechanisms of strontium. PMID:22172139

  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. Case-control study of prenatal ultrasonography exposure in children with delayed speech.

    PubMed Central

    Campbell, J D; Elford, R W; Brant, R F

    1993-01-01

    OBJECTIVE: To determine whether there is an association between prenatal ultrasound exposure and delayed speech in children. DESIGN: Case-control study. SETTING: Network of community physicians affiliated with the Primary Care Research Unit, University of Calgary. SUBJECTS: Thirty-four practitioners identified 72 children aged 24 to 100 months who had undergone a formal speech-language evaluation and were found to have delayed speech of unknown cause by a speech-language pathologist. For each case subject the practitioners found two control subjects matched for sex, date of birth, sibling birth order and associated health problems. MAIN OUTCOME MEASURES: Rates of prenatal ultrasound exposure and delayed speech. RESULTS: The children with delayed speech had a higher rate of ultrasound exposure than the control subjects. The findings suggest that a child with delayed speech is about twice as likely as a child without delayed speech to have been exposed to prenatal ultrasound waves (odds ratio 2.8, 95% confidence limit 1.5 to 5.3; p = 0.001). CONCLUSION: An association between prenatal ultrasonography exposure and delayed speech was found. If there is no obvious clinical indication for diagnostic in-utero ultrasonography, physicians might be wise to caution their patients about the vulnerability of the fetus to noxious agents. PMID:8221427

  5. Antidepressants and Gastric Cancer: A Nationwide Population-Based Nested Case-Control Study

    PubMed Central

    Lin, Chiao-Fan; Chan, Hsiang-Lin; Liang, Hsin-Yi; Lee, Yena; McIntyre, Roger S.; Chen, Vincent Chin-Hung

    2015-01-01

    Background To our knowledge, no epidemiological study has reported on whether an association between antidepressant exposure and gastric cancer exists. Herein, we aim to investigate the possible association between antidepressant exposure and gastric cancer incidence. Methods Using a nested case-control design, we identified 26289 cases with gastric cancer and 127984 controls from Taiwan’s National Health Insurance Research Database (NHIRD). The data were analyzed using a conditional logistic regression model adjusting for possible confounding variables. Results We found antidepressant use did not increase the risk of gastric cancer. The lack of an association between antidepressant prescription and elevated gastric cancer incidence was apparent for across selective serotonin-reuptake inhibitors (SSRIs), tricyclic agents (TCAs), serotonin-norepinephrine reuptake inhibitors (SNRIs), reversible inhibitors of monoamine oxidase A (RIMA), trazodone, mirtazapine and bupropion. There were slightly decreased gastric cancer risks of SSRIs use (≧28 DDD group, adjusted OR = 0.87; 95% CI = 0.78–0.96). Sensitive analysis showed SSRIs, TCAs, and SNRIs did not increase gastric cancer risks significantly even in the group with peptic ulcer history. Conclusions An association between antidepressant exposure and gastric cancer was not apparent in this analysis. PMID:26606417

  6. Chronic beryllium disease and beryllium sensitization at Rocky Flats: a case-control study.

    PubMed

    Viet, S M; Torma-Krajewski, J; Rogers, J

    2000-01-01

    A case-control study was conducted to evaluate the risk of chronic beryllium disease (CBD) and beryllium sensitization (SENS) associated with various levels of historical beryllium exposure at the Rocky Flats nuclear weapons facility. Fifty CBD and 74 SENS cases were matched to controls of the same age group, race, gender, and smoking status. A job exposure matrix was developed from job history data and fixed airhead (FAH) exposure data available from 1960 to 1988. Job titles and building areas were assigned factors based on exposure relative to a machinist in the Building 444 Beryllium Shop. Concurrence on these factors was obtained from past and present Rocky Flats industrial hygienists. Using the matrix, long-term mean and cumulative exposures were estimated for each subject. Both exposure estimates (p < 0.0001) and years of employment (p = 0.010) were found to be significantly higher for CBD cases as compared with their controls, but not so for the SENS cases as compared with their controls. Logistic regression analyses showed statistically significant relationships between both cumulative and mean exposure and CBD, but not for SENS. These findings suggest that reduced worker exposures might lower the future incidence of CBD, but may not necessarily lower the incidence of SENS. PMID:10782196

  7. 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

  8. Childhood leukemia and 50 Hz magnetic fields: findings from the Italian SETIL case-control study.

    PubMed

    Salvan, Alberto; Ranucci, Alessandra; Lagorio, Susanna; Magnani, Corrado

    2015-02-01

    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

  9. Factors associated with adult poisoning in northern Malaysia: a case-control study.

    PubMed

    Fathelrahman, A I; Ab Rahman, A F; Zain, Z Mohd; Tengku, M A

    2006-04-01

    Data on adult risk factors associated with drug or chemical poisonings in Malaysia are scarce. The objective of the study was to identify possible risk factors associated with adult admissions to the Penang General Hospital (PGH) due to chemical poisoning and/or drug overdose. The present study was a case-control study, conducted over 18 weeks. One hundred acutely poisoned adult patients admitted to PGH during the period from September 2003 to February 2004 were considered as cases. Two hundred patients admitted to the same medical wards for other illnesses, during the same period, were matched for age and gender with the poisoned cases and thus selected as controls. McNemar test and binary logistic were used for univariate analysis and logistic regression analysis for multivariate analyses. The odds ratio (OR) and its 95% confidence interval (95% CI) were calculated for each predictor variable. Positive histories of psychiatric illness and previous poisoning, problems in boy/girl friend relationships, family problems, marital problems, Indian ethnicity, Chinese ethnicity, living in rented houses and living in a household with less than five people were significant risk factors associated with adult admissions due to poisoning. PMID:16696291

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

    PubMed Central

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

    2016-01-01

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

  11. 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

  12. A case-control study of pathogen and lifestyle risk factors for diarrhoea in dogs.

    PubMed

    Stavisky, Jenny; Radford, Alan David; Gaskell, Rosalind; Dawson, Susan; German, Alex; Parsons, Bryony; Clegg, Simon; Newman, Jenny; Pinchbeck, Gina

    2011-05-01

    Diarrhoea is a common and multi-factorial condition in dogs, the aetiology of which is often incompletely understood. A case-control study was carried out to compare the carriage of some common canine enteric pathogens (enteric coronavirus, parvovirus, distemper, endoparasites, Campylobacter and Salmonella spp.), as well as lifestyle factors such as vaccination history, diet and contact with other species, in dogs presenting at first opinion veterinary practices with and without diarrhoea. Multivariable conditional logistic regression showed that dogs in the study which scavenged or had had a recent change of diet (OR 3.5, p=0.002), had recently stayed in kennels (OR 9.5, p=0.01), or were fed a home-cooked diet (OR 4, p=0.002) were at a significantly greater risk of diarrhoea, whilst being female (OR 0.4, p=0.01), currently up to date with routine vaccinations (OR 0.4, p=0.05) and having contact with horse faeces (OR 0.4, p=0.06) were associated with a reduced risk. None of the pathogens tested for was a significant factor in the final multivariable model suggesting that in this predominantly vaccinated population, diarrhoea may be more associated with lifestyle risk factors than specific pathogens. PMID:21420191

  13. An exploratory case-control study of brain tumors in children.

    PubMed

    Howe, G R; Burch, J D; Chiarelli, A M; Risch, H A; Choi, B C

    1989-08-01

    An exploratory case-control study of childhood brain tumors was conducted in southern Ontario between 1977 and 1983, on 74 cases and 138 age- and sex-matched population controls. A significantly elevated risk (perhaps due to early case symptoms) was seen for skull X-rays at least 5 years prior to diagnosis, and for head or neck injuries which required medical attention. However, no evidence of an increased risk appeared for exposure to sick pets or to pesticides, maternal or paternal history of smoking, and various birth characteristics or antenatal exposure of the child, though these have previously been reported to be associated with childhood brain tumors. With respect to the hypothesis that N-nitroso compounds may be involved in the etiology of childhood brain tumors, most exposures of this type were not associated with risk, though a significant positive association was seen for consumption of beer by the mother during pregnancy, and a significant negative association was seen with consumption of fruit juice by the child. Other findings in the present study include an association with developmental problems relating to height and weight and with certain socioeconomic characteristics of the mother. Further investigation of these results in future studies is warranted. PMID:2743324

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

    PubMed Central

    Archer, V. E.

    1988-01-01

    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. PMID:3051699

  15. Self-reported psychological stress and the risk of breast cancer: a case-control study.

    PubMed

    Kruk, Joanna

    2012-03-01

    The aim of this study was to examine the relationship between severe life events and breast cancer risk. This study was based on a case-control examination of 858 Polish invasive breast cancer cases and 1085 controls matched for age and place of residence. Data on life events, sociodemographic characteristic, reproductive factors, family history of breast cancer, current weight and height, and lifestyle habits were collected between January 2003 and May 2007 using a self-administered questionnaire. Odds ratios with 95% confidence intervals were estimated as the measure of the relationship between life event stress and breast cancer risk using unconditional logistic regression analyses. After adjustment for potential breast cancer risk factors, women with four to six individual major life events had 5.33 times higher risk for breast cancer, compared with those in the lowest quartile. Similarly, women with a lifetime life change score greater than 210 had about 5 times higher risk compared to women with corresponding scores in the range 0-70. Several life events (death of a close family member, personal injury or illness, imprisonment/trouble with the law, retirement) were significantly associated with breast cancer risk. These findings suggest that major life events can play an important role in the etiology of breast cancer. PMID:21875303

  16. A case-control study of the possible association between oral contraceptives and malignant melanoma.

    PubMed Central

    Adam, S. A.; Sheaves, J. K.; Wright, N. H.; Mosser, G.; Harris, R. W.; Vessey, M. P.

    1981-01-01

    In a case-control study, we investigated 169 women aged 15-49 years with malignant melanoma notified to the Oxford and South Western cancer registries during the years 1971-1976, together with 507 matched controls. Data about medical, reproductive, drug and smoking histories were obtained both by reviewing general practitioner (GP) records and from the women themselves by postal questionnaires. There was no significant evidence of any overall increase in the risk of melanoma in oral contraceptive (OC) users (data from GP records-ever use vs never use, relative risk (RR) 1.34, 95% confidence limits 0.92-1.96; corresponding data from postal questionnaires-RR 1.13, limits 0.73-1.75). However, although not significant, the risk estimated from data in the postal questionnaires was higher in women who had used OCs for 5 years or more (use greater than or equal to 5 years vs never use, RR 1.57, limits 0.83-3.03). Previously demonstrated risk factors for melanoma, such as fair skin, blond or red hair and Celtic origin were found to be commoner in the cases than in the controls. Data from the Oxford/Family Planning Association contraceptive study were also examined. Unexpectedly there was a strong suggestion of a negative association between OC use and melanoma risk, but the analysis was based on only 12 women with the disease. PMID:7259960

  17. Preventing birth defects: The value of the NBDPS case-control approach.

    PubMed

    Dolk, Helen

    2015-08-01

    Birth Defect Registries provide a basis for epidemiological research into risk factors, thus facilitating a growing understanding of what causes congenital anomalies and how one might target preventive public health actions and reduce inequalities. The National Birth Defects Prevention Study (NBDPS) has used 10 U.S. registries as a basis for a large case-control study. This commentary reviews its methodology and selected areas of output. The strengths of NBDPS lie in the quality of diagnostic coding and classification of birth defects and its size. The sources of bias in NBDPS data relate particularly to retrospective exposure ascertainment entailing a long period of recall, incomplete ascertainment of terminations of pregnancy for fetal anomaly, and unknown bias in case selection. NBDPS results have shown the protective effect of healthy dietary patterns, but have not been as informative as expected in relation to furthering understanding of the protective effect of folic acid. NBDPS medication studies are making important contributions to addressing the gap in existing evidence systematically across a wide range of birth defects, but are challenged by the quality of information on exposure, dose and underlying disease condition, and the interpretation of results of multiple testing. Studies of environmental contaminants in collaboration with experts in exposure assessment have linked addresses to residential exposure measures, using the advantages of information on residential history and confounders, but are challenged by the need to consider exposure mixtures. NBDPS could increase its public health impact by placing more emphasis on socioeconomic inequalities. PMID:26172859

  18. Consultation for Small-Sized Penis in the Egyptian Males: A Case Control Study.

    PubMed

    Salama, Nader

    2016-05-01

    This study aimed to report penile dimensions in adult Egyptian males consulting for small-sized penis (SSP) and describe their demographics and andrological profile. A case control study was designed through retrospective data analysis of patients (n = 239) seeking advice for SSP and a control group (n = 59). This included sociodemographics, other andrological complaints, and penile dimensions (pendulous length [PL], penopubic or total length [TL], and circumference [CF]) at flaccid and erect states and the size of the prepubic fatty pad. The results reported that most patients were single, students, and smokers and had not completed a university education. Several patients reported falsely premature ejaculation (PE), penile curvature (PC), and small-sized testes. Most penile dimensions of the patients (mean, cm) were significantly lower than those of the controls, whether in flaccid (PL: 7.4 vs. 8.05, p = .008; CF: 8.7 vs. 8.98, p = .026) or erect state (PL: 11.8 vs. 13, p = .000; TL: 14.2 vs. 15, p = .000; CF: 11.3 vs. 11.8, p = .003). However, no patient presented with a pendulous penile length <4 cm in flaccid or <7 cm in erect state. In conclusion, Egyptian men consulting for SSP did not have true small organs, but their penile dimensions were slightly smaller than those of men without such complaint. The proper sexual education program is highly advisable in these situations to avoid the myths and misconceptions about sexuality. PMID:25563384

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

    PubMed Central

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

    2016-01-01

    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. PMID:27483316

  20. A nested case-control study of lung cancer among silica exposed workers in China.

    PubMed

    McLaughlin, J K; Chen, J Q; Dosemeci, M; Chen, R A; Rexing, S H; Wu, Z; Hearl, F J; McCawley, M A; Blot, W J

    1992-03-01

    In an attempt to assess whether silica induces lung cancer, a nested case-control study of 316 male lung cancer cases and 1352 controls was carried out among pottery workers and tungsten, copper-iron, and tin miners from five provinces in south central China. Exposure to dust and silica for each study subject was evaluated quantitatively by cumulative exposure measures based on historical industrial hygiene records. Measurements on confounders such as inorganic arsenic, polycyclic aromatic hydrocarbons (PAHs), and radon were also collected from the worksites. Information on cigarette smoking was obtained by interviews of the subjects or their next of kin. A significant trend of increasing risk of lung cancer with exposure to silica was found for tin miners, but not for miners working in tungsten or copper-iron mines. Concomitant and highly correlated exposures to arsenic and PAHs among tin miners were also found. Risk of lung cancer among pottery workers