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Sample records for multicenter case-control samples

  1. 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

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

    PubMed Central

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

    2008-01-01

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

  3. Environmental risk factors in pediatric psoriasis: a multicenter case-control study.

    PubMed

    Ozden, Müge G; Tekin, Nilgün S; Gürer, Mehmet A; Akdemir, Devrim; Doğramacı, Ciğdem; Utaş, Serap; Akman, Ayşe; Evans, Sibel E; Bahadır, Sevgi; Oztürkcan, Serap; Ikizoğlu, Güliz; Sendur, Neslihan; Köse, Osman; Bek, Yüksel; Yaylı, Savaş; Cantürk, Tayyar; Turanl, Ahmet Y

    2011-01-01

    To analyze the effect of possible risk factors, including breastfeeding, on the development of childhood-onset psoriasis, a multicenter case-control study with prospective collection of data was performed. Using a standard questionnaire, personal and specific variables including family history of psoriasis, maternal and environmental tobacco smoke exposure, body mass index (BMI), exclusive and partial breastfeeding for at least 3 and 12 months, cow's milk intake before 1 year, birth delivery method, and stressful life events were collected during 2009 from 537 patients with psoriasis and 511 controls younger than 18. Overall, patients more frequently reported exposure to environmental tobacco smoke at home and stressful life events in the year preceding the diagnosis than controls. The odds ratios (OR) for smoking and stressful life events were 2.90 (95% confidence interval [CI]=2.27-3.78) and 2.94 (95% CI=2.28-3.79), respectively. In addition, children with psoriasis were more likely to have a higher BMI (>26) than controls (OR=2.52; 95% CI=1.42-4.49). High BMI, environmental tobacco smoke exposure at home, and stressful life events may influence the development of pediatric psoriasis.

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

    PubMed

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

    2001-05-01

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

  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. Active and involuntary tobacco smoking and upper-aerodigestive-tract cancer risks in a multicenter case-control study

    PubMed Central

    Lee, Yuan-Chin Amy; Marron, Manuela; Benhamou, Simone; Bouchardy, Christine; Ahrens, Wolfgang; Pohlabeln, Hermann; Lagiou, Pagona; Trichopoulos, Dimitrios; Agudo, Antonio; Castellsague, Xavier; Bencko, Vladimir; Holcatova, Ivana; Kjaerheim, Kristina; Merletti, Franco; Richiardi, Lorenzo; Macfarlane, Gary J.; Macfarlane, Tatiana V.; Talamini, Renato; Barzan, Luigi; Canova, Cristina; Simonato, Lorenzo; Conway, David I.; McKinney, Patricia A.; Lowry, Raymond J.; Sneddon, Linda; Znaor, Ariana; Healy, Claire M.; McCartan, Bernard E.; Brennan, Paul; Hashibe, Mia

    2012-01-01

    Introduction Several important issues for the established association between tobacco smoking and upper-aerodigestive tract (UADT) cancer risks include the associations with smoking by cancer subsite, by type of tobacco, and among never alcohol drinkers, and the associations with involuntary smoking among nonsmokers. Our aim was to examine these specific issues in a large scale case-control study in Europe. Methods Analysis was performed on 2,103 UADT squamous cell carcinoma cases and 2,221 controls in the Alcohol-Related Cancers and Genetic Susceptibility in Europe (ARCAGE) project, a multicenter case-control study in 10 European countries. Unconditional logistic regression was performed to obtain odds ratios (OR) and 95% confidence intervals (CI). Results Compared to never tobacco smoking, current smoking was associated with UADT cancer risks (OR=6.72, 95% CI 5.45–8.30 for overall; 5.83, 4.50–7.54 for oral cavity and oropharynx; 12.19, 8.29–17.92 for hypopharynx and larynx; 4.17, 2.45–7.10 for esophagus). Among never drinkers, dose-response relationships with tobacco smoking packyears were observed for hypopharyngeal and laryngeal cancers (ptrend = 0.01), but not for oral cavity and oropharyngeal cancers (ptrend = 0.282). Among never smokers, ever exposure to involuntary smoking was associated with an increased risk of UADT cancers (OR=1.60, 95% CI 1.04–2.46). Conclusion Our results corroborate that tobacco smoking may play a stronger role in the development of hypopharyngeal and laryngeal cancers than that of oral cavity and oropharyngeal cancers among never drinkers and that involuntary smoking is an important risk factor for UADT cancers. Public health interventions to reduce involuntary smoking exposure could help reduce UADT cancer incidence. PMID:19959682

  7. Bile acids in a multicenter, population-based case-control study of stillbirth

    PubMed Central

    Silver, Robert M.; Parker, Corette B.; Goldenberg, Robert; Reddy, Uma M.; Dudley, Donald J.; Saade, George R.; Hogue, Carol J. Rowland; Coustan, Donald; Varner, Michael W.; Koch, Matthew A.; Conway, Deborah; Bukowski, Radek; Pinar, Halit; Stoll, Barbara; Moore, Janet; Willinger, Marian

    2015-01-01

    OBJECTIVE We sought to compare bile acids in women with and without stillbirth in a population-based study. STUDY DESIGN The Stillbirth Collaborative Research Network conducted a multisite, population-based case-control study of stillbirth (fetal deaths ≥20 weeks). Maternal sera were obtained at the time of enrollment and frozen at −80° until assay for bile acids. RESULTS Assays were performed in 581 women with stillbirth and 1546 women with live births. Bile acid levels were slightly higher in women with stillbirth (geometric mean [95% confidence interval {CI}] = 3.2 [3.0–3.5]) compared to live births (2.9 [2.7–3.1], P = .0327). However, the difference was not significant after adjustment for baseline risk factors for stillbirth. The proportion of women with elevated levels (≥10 or ≥40 μmol/L) was similar in stillbirths and live births. Results were similar when the analysis was limited to subsets of stillbirths and live births. In women with stillbirths not associated with fetal anomalies or obstetric complications bile acid levels were higher than in women with term live births (geometric mean [95% CI] = 3.4 [3.0–3.8] vs 2.9 [2.7–3.0], P = .0152, unadjusted; P = .06, adjusted). However, a similar proportion of women in both groups had levels ≥10 mmol/L (10.7 vs 7.2%; odds ratio [OR], 1.54; 95% CI, 0.97–2.44; adjusted OR, 1.29; 95% CI, 0.78–2.15) and ≥40 μmol/L (1.7 vs 0.7%; OR, 2.58; 95% CI, 0.85–7.84; adjusted OR, 2.28; 95% CI, 0.79–6.56). CONCLUSION Our data do not support testing for bile acids in cases of stillbirth in the absence of clinical evidence of intrahepatic cholestasis of pregnancy. PMID:24215860

  8. Smoking addiction and the risk of upper-aerodigestive-tract cancer in a multicenter case-control study.

    PubMed

    Lee, Yuan-Chin Amy; Zugna, Daniela; Richiardi, Lorenzo; Merletti, Franco; Marron, Manuela; Ahrens, Wolfgang; Pohlabeln, Hermann; Lagiou, Pagona; Trichopoulos, Dimitrios; Agudo, Antonio; Castellsague, Xavier; Betka, Jaroslav; Holcatova, Ivana; Kjaerheim, Kristina; Macfarlane, Gary J; Macfarlane, Tatiana V; Talamini, Renato; Barzan, Luigi; Canova, Cristina; Simonato, Lorenzo; Conway, David I; McKinney, Patricia A; Thomson, Peter; Znaor, Ariana; Healy, Claire M; McCartan, Bernard E; Boffetta, Paolo; Brennan, Paul; Hashibe, Mia

    2013-12-01

    Although previous studies on tobacco and alcohol and the risk of upper-aerodigestive-tract (UADT) cancers have clearly shown dose-response relations with the frequency and duration of tobacco and alcohol, studies on addiction to tobacco smoking itself as a risk factor for UADT cancer have not been published, to our knowledge. The aim of this report is to assess whether smoking addiction is an independent risk factor or a refinement to smoking variables (intensity and duration) for UADT squamous cell carcinoma (SCC) risk in the multicenter case-control study (ARCAGE) in Western Europe. The analyses included 1,586 ever smoking UADT SCC cases and 1,260 ever smoking controls. Addiction was measured by a modified Fagerström score (first cigarette after waking up, difficulty refraining from smoking in places where it is forbidden and cigarettes per day). Adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for UADT cancers with addiction variables were estimated with unconditional logistic regression. Among current smokers, the participants who smoked their first cigarette within 5 min of waking up were two times more likely to develop UADT SCC than those who smoked 60 min after waking up. Greater tobacco smoking addiction was associated with an increased risk of UADT SCC among current smokers (OR = 3.83, 95% CI: 2.56-5.73 for score of 3-7 vs. 0) but not among former smokers. These results may be consistent with a residual effect of smoking that was not captured by the questionnaire responses (smoking intensity and smoking duration) alone, suggesting addiction a refinement to smoking variables.

  9. 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

  10. 77 FR 12598 - Notice Correction; A Multi-Center International Hospital-Based Case-Control Study of Lymphoma in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-01

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

  11. 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

  12. Nutritional and genetic determinants of vitamin B and homocysteine metabolisms in neural tube defects: a multicenter case-control study.

    PubMed

    Candito, Mirande; Rivet, Romain; Herbeth, Bernard; Boisson, Catherine; Rudigoz, René-Charles; Luton, Dominique; Journel, Hubert; Oury, Jean-François; Roux, François; Saura, Robert; Vernhet, Isabelle; Gaucherand, Pascal; Muller, Françoise; Guidicelli, Béatrice; Heckenroth, Hélène; Poulain, Patrice; Blayau, Martine; Francannet, Christine; Roszyk, Laurence; Brustié, Cécile; Staccini, Pascal; Gérard, Philippe; Fillion-Emery, Nathalie; Guéant-Rodriguez, Rosa-Maria; Van Obberghen, Emmanuel; Guéant, Jean-Louis

    2008-05-01

    Neural tube defects (NTDs) are severe congenital malformations due to failure of neural tube formation in early pregnancy. The proof that folic acid prevents NTDs raises the question of whether other parts of homocysteine (Hcy) metabolism may affect rates of NTDs. This French case-control study covered: 77 women aged 17-42 years sampled prior to elective abortion for a severe NTDs (cases) and 61 women aged 20-43 years with a normal pregnancy. Plasma and erythrocyte folate, plasma B6, B12 and Hcy were tested as five polymorphisms MTHFR 677 C --> T, MTHFR 1298 A --> C, MTR 2756 A --> G, MTTR 66 A --> G and TCN2 776 C --> G. Cases had significantly lower erythrocyte folate, plasma folate, B12 and B6 concentrations than the controls, and higher Hcy concentration. The odds ratio was 2.15 (95% CI: 1.00-4.59) for women with the MTRR 66 A --> G allele and it was decreased for mothers carrying the MTHFR 1298 A --> C allele. In multivariate analysis, only the erythrocyte folate concentration (P = 0.005) and plasma B6 concentration (P = 0.020) were predictors. Red cell folate is the main determinant of NTDs in France. Folic acid supplement or flour fortification would prevent most cases. Increased consumption of vitamins B12 and B6 could contribute to the prevention of NTDs. Genetic polymorphisms played only a small role. Until folic acid fortification becomes mandatory, all women of reproductive age should consume folic acid in a multivitamin that also contains B12 and B6.

  13. 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

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

    PubMed

    Marozzi, Marco

    2015-04-30

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

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

    PubMed Central

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

    2009-01-01

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

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

    PubMed Central

    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

  17. Risk factors for hepatocellular carcinoma in cirrhosis due to nonalcoholic fatty liver disease: A multicenter, case-control study

    PubMed Central

    Corey, Kathleen E; Gawrieh, Samer; deLemos, Andrew S; Zheng, Hui; Scanga, Andrew E; Haglund, Jennifer W; Sanchez, Jorge; Danford, Christopher J; Comerford, Megan; Bossi, Krista; Munir, Samina; Chalasani, Naga; Wattacheril, Julia

    2017-01-01

    AIM To identify risk factors associated with hepatocellular carcinoma (HCC), describe tumor characteristics and treatments pursed for a cohort of individuals with nonalcoholic steatohepatitis (NASH) cirrhosis. METHODS We conducted a retrospective case-control study of a well-characterized cohort of patients among five liver transplant centers with NASH cirrhosis with (cases) and without HCC (controls). RESULTS Ninety-four cases and 150 controls were included. Cases were significantly more likely to be male than controls (67% vs 45%, P < 0.001) and of older age (61.9 years vs 58 years, P = 0.002). In addition, cases were more likely to have had complications of end stage liver disease (83% vs 71%, P = 0.032). On multivariate analysis, the strongest association with the presence of HCC were male gender (OR 4.3, 95%CI: 1.83-10.3, P = 0.001) and age (OR = 1.082, 95%CI: 1.03-1.13, P = 0.001). Hispanic ethnicity was associated with a decreased prevalence of HCC (OR = 0.3, 95%CI: 0.09-0.994, P = 0.048). HCC was predominantly in the form of a single lesion with regional lymph node(s) and distant metastasis in only 2.6% and 6.3%, respectively. Fifty-nine point three percent of individuals with HCC underwent locoregional therapy and 61.5% underwent liver transplantation for HCC. CONCLUSION Male gender, increased age and non-Hispanic ethnicity are associated with HCC in NASH cirrhosis. NASH cirrhosis associated HCC in this cohort was characterized by early stage disease at diagnosis and treatment with locoregional therapy and transplant. PMID:28321274

  18. 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.

  19. Is there an association between prior anti-inflammatory drug exposure and occurrence of peritonsillar abscess (PTA)? A national multicenter prospective observational case-control study.

    PubMed

    Lepelletier, D; Pinaud, V; Le Conte, P; Bourigault, C; Asseray, N; Ballereau, F; Caillon, J; Ferron, C; Righini, C; Batard, E; Potel, G

    2017-01-01

    The aim of this study was to evaluate whether recent systemic anti-inflammatory agents (AIAs) exposure in patients with sore throat managed with or without antibiotic therapy influenced the risk of peritonsillar abscess (PTA). We conducted a multicenter case-control study in 13 French university hospitals in 2009-2012 comparing patients admitted with PTA to matched controls: patients with sore throat but without PTA who were followed up for 10 days after visiting their primary-care physician. In the multivariate stepwise logistic regression model comparing 120 cases with PTA to 143 controls, factors significantly associated with PTA were male gender (odds ratio [OR], 2.0; p = 0.03), smoking (OR, 2.0; p = 0.03), and prior self-medication with systemic AIAs (OR, 3.5; p = 0.01). Topical treatment was associated with significant protection against PTA (OR, 0.3; p < 0.001). In conclusion, self-medication with systemic AIAs appears to be an independent factor associated with the occurrence of PTA. This is an important message as non-steroidal AIAs access is favored by their over-counter availability in pharmacies. This finding must be interpreted with caution due to the study design and a prospective, randomized study is needed to substantiate these possible causal risk factors.

  20. Mendelian Randomization Studies for a Continuous Exposure Under Case-Control Sampling

    PubMed Central

    Dai, James Y.; Zhang, Xinyi Cindy

    2015-01-01

    In this article, we assess the impact of case-control sampling on mendelian randomization analyses with a dichotomous disease outcome and a continuous exposure. The 2-stage instrumental variables (2SIV) method uses the prediction of the exposure given genotypes in the logistic regression for the outcome and provides a valid test and an approximation of the causal effect. Under case-control sampling, however, the first stage of the 2SIV procedure becomes a secondary trait association, which requires proper adjustment for the biased sampling. Through theoretical development and simulations, we compare the naïve estimator, the inverse probability weighted estimator, and the maximum likelihood estimator for the first-stage association and, more importantly, the resulting 2SIV estimates of the causal effect. We also include in our comparison the causal odds ratio estimate derived from structural mean models by double-logistic regression. Our results suggest that the naïve estimator is substantially biased under the alternative, yet it remains unbiased under the null hypothesis of no causal effect; the maximum likelihood estimator yields smaller variance and mean squared error than other estimators; and the structural mean models estimator delivers the smallest bias, though generally incurring a larger variance and sometimes having issues in algorithm stability and convergence. PMID:25713335

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

    PubMed

    Joseph, Lawrence; Bélisle, Patrick

    2013-12-01

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

  2. 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

  3. Spanish Multicenter Normative Studies (NEURONORMA Project): methods and sample characteristics.

    PubMed

    Peña-Casanova, Jordi; Blesa, Rafael; Aguilar, Miquel; Gramunt-Fombuena, Nina; Gómez-Ansón, Beatriz; Oliva, Rafael; Molinuevo, José Luis; Robles, Alfredo; Barquero, María Sagrario; Antúnez, Carmen; Martínez-Parra, Carlos; Frank-García, Anna; Fernández, Manuel; Alfonso, Verónica; Sol, Josep M

    2009-06-01

    This paper describes the methods and sample characteristics of a series of Spanish normative studies (The NEURONORMA project). The primary objective of our research was to collect normative and psychometric information on a sample of people aged over 49 years. The normative information was based on a series of selected, but commonly used, neuropsychological tests covering attention, language, visuo-perceptual abilities, constructional tasks, memory, and executive functions. A sample of 356 community dwelling individuals was studied. Demographics, socio-cultural, and medical data were collected. Cognitive normality was validated via informants and a cognitive screening test. Norms were calculated for midpoint age groups. Effects of age, education, and sex were determined. The use of these norms should improve neuropsychological diagnostic accuracy in older Spanish subjects. These data may also be of considerable use for comparisons with other normative studies. Limitations of these normative data are also commented on.

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

    PubMed Central

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

    2013-01-01

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

  5. Carcinogen metabolism in human lung tissues and the effect of tobacco smoking: results from a case--control multicenter study on lung cancer patients.

    PubMed Central

    Bartsch, H; Petruzzelli, S; De Flora, S; Hietanen, E; Camus, A M; Castegnaro, M; Alexandrov, K; Rojas, M; Saracci, R; Giuntini, C

    1992-01-01

    Cigarette smoking is the strongest risk factor for lung cancer, but genetically determined variations in the activities of pulmonary enzyme that metabolize tobacco-derived carcinogens may affect individual risk. To investigate whether these enzymes (e.g., CYP1A-related) can serve as markers for carcinogen-DNA damage, lung tissue specimens were taken during surgery from middle-aged men with either lung cancer or non-neoplastic lung disease. Phase I [aryl hydrocarbon hydroxylase (AHH), ethoxycoumarin O-deethylase (ECOD)] and phase II (epoxide hydrolase, UDP-glucuronosyltransferase, glutathione S-transferase) enzyme activities, glutathione and malondialdehyde contents were determined in lung parenchyma and/or bronchial tissues; some samples were also analyzed for DNA adducts, using 32P-postlabeling. The data were then analyzed for the following: a) differences in metabolic profiles between bronchial and parenchymal lung tissue; b) the effect of recent exposure to tobacco smoke on enzyme inducibility and benzo[a]pyrene metabolism; c) differences in enzyme inducibility between lung cancer and non-lung cancer patients; d) the effect of smoking on metabolism of mutagens in vitro; e) pulmonary DNA adduct levels and AHH activity in lung parenchyma of smokers and ex-smokers; f) lipid peroxidation products in lung tissue from lung cancer and non-lung cancer patients, as related to smoking habits and degree of airway obstruction; and g) prognostic value of AHH pulmonary activity in lung cancer patients. The results demonstrate a pronounced effect of tobacco smoke on pulmonary metabolism of xenobiotics and prooxidant state and suggest the existence of a metabolic phenotype at higher risk for tobacco-associated lung cancer. PMID:1336722

  6. Replication of association between schizophrenia and ZNF804A in the Irish Case Control Study of Schizophrenia (ICCSS) sample

    PubMed Central

    Riley, Brien; Thiselton, Dawn; Maher, Brion S.; Bigdeli, Tim; Wormley, Brandon; McMichael, G. Omari; Fanous, Ayman H.; Vladimirov, Vladimir; O’Neill, F. Anthony; Walsh, Dermot; Kendler, Kenneth S.

    2009-01-01

    A recent genomewide association study reported association between schizophrenia and the ZNF804A gene on chromosome 2q32.1. We attempted to replicate these findings in our Irish Case-Control Study of Schizophrenia (ICCSS) sample (N=1021 cases, 626 controls). Following consultation with the original investigators we genotyped 3 of the most promising SNPs from the Cardiff study. We replicate association with rs1344706 (trend test one tailed p=0.0113 with the previously associated A allele) in ZNF804A. We detect no evidence of association with rs6490121 in NOS1 (one tailed p=0.21), and only a trend with rs9922369 in RGRIP1L (one tailed p=0.0515). Based on these results, we completed genotyping of 11 additional LD-tagging SNPs in ZNF804A. Of 12 SNPs genotyped, 11 pass QC criteria and 4 are nominally associated, with our most significant evidence of association at rs7597593 (p=0.0013) followed by rs1344706. We observe no evidence of differential association in ZNF804A based on family history or sex of case. The associated SNP rs1344706 lies in ~30 bp of conserved mammalian sequence and the associated A allele is predicted to maintain binding sites for the brain-expressed transcription factors MYT1L and POU3F1/OCT-6. In controls, expression is significantly increased from the A allele of rs1344706 compared to the C allele. Expression is increased in schizophrenic cases compared to controls, but this difference does not achieve statistical significance. This study replicates the original reported association of ZNF804A with schizophrenia and suggests that there is a consistent link between the the A allele of rs1344706, increased expression of ZNF804A and risk for schizophrenia. PMID:19844207

  7. 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

  8. The impact of exposure-biased sampling designs on detection of gene-environment interactions in case-control studies with potential exposure misclassification.

    PubMed

    Stenzel, Stephanie L; Ahn, Jaeil; Boonstra, Philip S; Gruber, Stephen B; Mukherjee, Bhramar

    2015-05-01

    With limited funding and biological specimen availability, choosing an optimal sampling design to maximize power for detecting gene-by-environment (G-E) interactions is critical. Exposure-enriched sampling is often used to select subjects with rare exposures for genotyping to enhance power for tests of G-E effects. However, exposure misclassification (MC) combined with biased sampling can affect characteristics of tests for G-E interaction and joint tests for marginal association and G-E interaction. Here, we characterize the impact of exposure-biased sampling under conditions of perfect exposure information and exposure MC on properties of several methods for conducting inference. We assess the Type I error, power, bias, and mean squared error properties of case-only, case-control, and empirical Bayes methods for testing/estimating G-E interaction and a joint test for marginal G (or E) effect and G-E interaction across three biased sampling schemes. Properties are evaluated via empirical simulation studies. With perfect exposure information, exposure-enriched sampling schemes enhance power as compared to random selection of subjects irrespective of exposure prevalence but yield bias in estimation of the G-E interaction and marginal E parameters. Exposure MC modifies the relative performance of sampling designs when compared to the case of perfect exposure information. Those conducting G-E interaction studies should be aware of exposure MC properties and the prevalence of exposure when choosing an ideal sampling scheme and method for characterizing G-E interactions and joint effects.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. Risk Factors for HIV Diagnosis Among Men Who Have Sex with Men: Results of a Case-Control Study in One Sample of Eastern China.

    PubMed

    Yang, Zhongrong; Huang, Zhaohui; Dong, Zhengquan; Li, Jing; Zhang, Sichao; Wu, Nanping; Jin, Meihua

    2016-12-01

    Substantial increases in human immunodeficiency virus (HIV) have been reported worldwide in recent years, particularly among men who have sex with men (MSM). We conducted a matched case-control study to examine the factors associated with HIV diagnosis among MSM in one sample of eastern China. Between February 2012 and December 2014, we used surveillance records to identify MSM diagnosed with HIV (case participants); we also recruited MSM who did not have HIV (controls) and then matched them (2:1) with control cases in terms of age (±3 years). Multivariate logistic regression models were used to assess the factors associated with HIV diagnosis. According to a multivariate analysis using logistic regression model involving 101 cases and 202 matched controls, a lack of comprehensive knowledge of HIV (adjusted odds ratio [OR] = 0.40; 95% confidence interval [CI] = 0.18, 0.89), a monthly income of ≥4,000 RMB (adjusted OR = 2.99; 95% CI = 1.45, 6.16), having at least two male sexual partners in the past 6 months (adjusted OR = 2.85; 95% CI = 1.28, 6.31), participating in at least four anal sex experiences with a man in the past month (adjusted OR = 3.56; 95% CI = 1.64, 7.73), and having a current syphilis infection (adjusted OR = 3.30; 95% CI = 1.06, 10.25) were associated with an increased risk for HIV diagnosis. MSM with a comprehensive knowledge of HIV were at reduced risk of HIV diagnosis, whereas those with more male sexual partners, more male anal sexual experiences (including receptive or/and insertive anal intercourse, rimming, and fisting), and a current syphilis infection were at increased risk of HIV diagnosis. Focus on protection and safer sex behaviors during male sexual activity (i.e., consistent condom use, pre-exposure prophylaxis, closed sexual networks among MSM) would likely be effective for reducing the HIV transmission rate.

  15. Are nested case-control studies biased?

    PubMed Central

    Langholz, Bryan; Richardson, David

    2014-01-01

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

  16. Ras-Association Domain Family 1 Isoform A (RASSF1A) Gene Polymorphism rs1989839 is Associated with Risk and Metastatic Potential of Osteosarcoma in Young Chinese Individuals: A Multi-Center, Case-Control Study

    PubMed Central

    Xu, Hongwei; Zhan, Wang; Chen, Zhiyuan

    2016-01-01

    Background The ras-association domain family 1 isoform A (RASSF1A) gene serves as a bona fide tumor suppressor gene. The polymorphisms in RASSF1A were previously reported to be associated with the risk of solid malignant tumors. We hypothesized herein that RASSF1A gene polymorphisms are involved in the risk and prognosis of osteosarcoma (OS). Material/Methods We recruited 279 young OS cases and 286 tumor-free controls from the east Chinese population. Five tagSNPs of RASSF1A gene (rs2236947A/C, rs2073497A/C, rs1989839C/T, rs72932987C/T, and rs4688728G/T) were genotyped. DNA was isolated from blood samples and then underwent PCR analysis for genotyping. Results rs1989839C/T is an important predictor of osteosarcoma risk and outcome. The CT genotype of rs1989839 is highly related to elevated risk of osteosarcoma. Furthermore, rs1989839C/T is also associated with the Enneking stage of osteosarcoma and risk of lung metastasis. One of the other 4 SNPs, rs2236947A/C, shows a borderline significance in predicting osteosarcoma risk. Conclusions Our study is the first to prove that RASSF1A gene polymorphisms may potentially be predictive for osteosarcoma risk and prognosis. PMID:27880743

  17. [A case-control study of factors associated with repeat teen pregnancy based on a sample from a university maternity hospital].

    PubMed

    Silva, Andréa de Albuquerque Arruda; Coutinho, Isabela C; Katz, Leila; Souza, Alex Sandro Rolland

    2013-03-01

    Repeat teen pregnancy is a frequent issue and is considered an aggravating factor for increased maternal and fetal morbidity and social problems. The aim of the study was to identify factors associated with repeat teen pregnancy. A case-control study was conducted in 90 postpartum adolescents with more than one pregnancy (cases) and 90 adult women with a history of only one pregnancy during adolescence (controls). Statistical analysis used hierarchical logistic regression with 5% significance. Early sexual initiation (< 15 years), early age at first pregnancy (< 16 years), not raising the children themselves, and low family income (< one minimum wage) were associated with repeat teenage pregnancy, while partner change was inversely associated. Repeat teen pregnancy was mainly associated with reproductive and socioeconomic factors. Partner change appeared as a protective factor. Measures should be adopted during the postpartum period of teenage mothers in order to avoid repeat pregnancy.

  18. 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

  19. Levels of heavy metals and essential minerals in hair samples of children with autism in Oman: a case-control study.

    PubMed

    Al-Farsi, Yahya M; Waly, Mostafa I; Al-Sharbati, Marwan M; Al-Shafaee, Mohammed A; Al-Farsi, Omar A; Al-Khaduri, Maha M; Gupta, Ishita; Ouhtit, Allal; Al-Adawi, Samir; Al-Said, Mona F; Deth, Richard C

    2013-02-01

    Toxic levels of heavy metals and low levels of essential minerals have been suggested to play a critical role in the pathogenesis of autism spectrum disorders (ASD). This study documents the levels of heavy metals and essential minerals in hair samples of children with ASD in Muscat, the urbanized capital of Oman, Muscat. The study included 27 children with ASD and 27 matched non-ASD controls. Parental interviews were held and dietary intake questionnaires completed in conjunction with the collection of hair samples. Analysis of heavy metals and essential minerals was carried out by inductively coupled plasma mass spectrometry. Chi-square analysis and non-parametric Fisher's exact tests were used to assess statistical significance. Children with ASD had significantly higher levels of all 11 analyzed heavy metals in their hair samples (P < 0.05), ranging from 150 to 365 % of control levels. ASD children also had significantly higher levels of essential minerals sulfur, sodium, magnesium, potassium, zinc, and iron, but lower levels of calcium and copper in their hair samples. This study corroborates data from previous studies in different parts of the world indicating the presence of elevated levels of heavy metals and selective depletion of essential minerals in the hair of children with ASD.

  20. CERAMIC: Case-Control Association Testing in Samples with Related Individuals, Based on Retrospective Mixed Model Analysis with Adjustment for Covariates

    PubMed Central

    Zhong, Sheng; McPeek, Mary Sara

    2016-01-01

    We consider the problem of genetic association testing of a binary trait in a sample that contains related individuals, where we adjust for relevant covariates and allow for missing data. We propose CERAMIC, an estimating equation approach that can be viewed as a hybrid of logistic regression and linear mixed-effects model (LMM) approaches. CERAMIC extends the recently proposed CARAT method to allow samples with related individuals and to incorporate partially missing data. In simulations, we show that CERAMIC outperforms existing LMM and generalized LMM approaches, maintaining high power and correct type 1 error across a wider range of scenarios. CERAMIC results in a particularly large power increase over existing methods when the sample includes related individuals with some missing data (e.g., when some individuals with phenotype and covariate information have missing genotype), because CERAMIC is able to make use of the relationship information to incorporate partially missing data in the analysis while correcting for dependence. Because CERAMIC is based on a retrospective analysis, it is robust to misspecification of the phenotype model, resulting in better control of type 1 error and higher power than that of prospective methods, such as GMMAT, when the phenotype model is misspecified. CERAMIC is computationally efficient for genomewide analysis in samples of related individuals of almost any configuration, including small families, unrelated individuals and even large, complex pedigrees. We apply CERAMIC to data on type 2 diabetes (T2D) from the Framingham Heart Study. In a genome scan, 9 of the 10 smallest CERAMIC p-values occur in or near either known T2D susceptibility loci or plausible candidates, verifying that CERAMIC is able to home in on the important loci in a genome scan. PMID:27695091

  1. Replication of bipolar disorder susceptibility alleles and identification of 2 novel genome-wide significant associations in a new bipolar disorder case-control sample

    PubMed Central

    Green, Elaine K; Hamshere, Marian; Forty, Liz; Gordon-Smith, Katherine; Fraser, Christine; Russell, Elen; Grozeva, Detelina; Kirov, George; Holmans, Peter; Moran, Jennifer L; Purcell, Shaun; Sklar, Pamela; Owen, Michael J; O’Donovan, Michael C; Jones, Lisa; Jones, Ian R; Craddock, Nick

    2014-01-01

    We have conducted a genotyping study using a custom Illumina Infinium HD genotyping array, the ImmunoChip, in a new UK sample of 1,218 bipolar disorder cases and 2,913 controls that have not been used in any studies previously reported independently or in meta-analyses. The ImmunoChip was designed prior to the publication of the Psychiatric GWAS Consortium Bipolar Disorder Working Group (PGC-BD) meta-analysis data. As such 3106 SNPs with a P value less than 1×10−3 from the bipolar disorder meta-analysis by Ferreira et al., 2008 were genotyped. We report support for two of the three most strongly associated chromosomal regions in the Ferreira study, CACNA1C (rs1006737, p=4.09×10−4) and 15q14 (rs2172835, p=0.043) but not ANK3 (rs10994336, p=0.912). We have combined our ImmunoChip data (569 quasi-independent SNPs from the 3016 SNPs genotyped) with the recently published PGC-BD meta-analysis data, using either the PGC-BD combined discovery and replication data where available or just the discovery data where the SNP was not typed in a replication sample in PGC-BD. Our data provide support for two regions, at ODZ4 and CACNA1C, with prior evidence for genome-wide significant association in PGC-BD meta-analysis. In addition, the combined analysis shows two novel genome-wide significant associations. First, rs7296288 (P = 8.97 × 10−9, OR = 0.9), an intergenic polymorphism on chromosome 12 located between RHEBL1 and DHH. Secondly, rs3818253 (P = 3.88 × 10−8, OR = 1.16), an intronic SNP on chromosome 20q11.2 in the gene TRPC4AP which lies in a high linkage disequilibrium region along with the genes GSS and MYH7B. PMID:23070075

  2. 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

  3. Large-scale prospective T cell function assays in shipped, unfrozen blood samples: experiences from the multicenter TRIGR trial.

    PubMed

    Hadley, David; Cheung, Roy K; Becker, Dorothy J; Girgis, Rose; Palmer, Jerry P; Cuthbertson, David; Krischer, Jeffrey P; Dosch, Hans-Michael

    2014-02-01

    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.

  4. The dopamine transporter gene and the impulsivity phenotype in attention deficit hyperactivity disorder: a case-control association study in a Korean sample.

    PubMed

    Kim, Jae-won; Kim, Boong-nyun; Cho, Soo-churl

    2006-12-01

    The dopamine transporter gene (DAT1) has been extensively studied as one of the candidate genes in attention-deficit/hyperactivity disorder (ADHD). Several studies have reported on the association between the DAT1 10-repeat allele and cognitive variables in ADHD. However, few studies have been designed to ascertain the association between DAT1 genotypes other than the 10-repeat allele and cognitive endophenotypes in ADHD. The aim of this study was to examine the relationship between the DAT1 genotypes and the candidate endophenotypes, inattention and impulsivity symptoms, as measured by the continuous performance test (CPT), in a Korean sample of 85 children diagnosed with DSM-IV ADHD. Compared to the normal control group, the frequencies of the 9/10 genotype were significantly higher in the ADHD probands (chi(2)=13.45, p=0.02, OR=4.12, 95% CI: 2.21-12.34) and parents of probands (chi(2)=11.60, p=0.03). The 9-repeat allele frequencies were significantly higher in the ADHD probands (chi(2)=11.55, p=0.03, OR=4.43, 95% CI: 1.55-11.78) and parents of probands (chi(2)=12.70,p=0.03) than the normal control group. Compared to the ADHD probands without the 9-repeat allele (n=74), the mean T-score, with regard to the commission errors of the CPT, was significantly higher (p<0.05) in the ADHD probands with the 9-repeat allele (n=11). Compared to the ADHD probands with other DAT1 genotypes, the mean T-score, with respect to the commission errors of the CPT, was significantly higher in the ADHD probands with the 9/10 genotype (p<0.05). The results of this study suggest the possibility of an association between the DAT1 9-repeat allele and the impulsivity phenotype of ADHD.

  5. 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

  6. Case-control studies: basic concepts.

    PubMed

    Vandenbroucke, Jan P; Pearce, Neil

    2012-10-01

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

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

    PubMed

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

    2014-01-01

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

  8. Bolting multicenter solutions

    NASA Astrophysics Data System (ADS)

    Bena, Iosif; Bossard, Guillaume; Katmadas, Stefanos; Turton, David

    2017-01-01

    We introduce a solvable system of equations that describes non-extremal multicenter solutions to six-dimensional ungauged supergravity coupled to tensor multiplets. The system involves a set of functions on a three-dimensional base metric. We obtain a family of non-extremal axisymmetric solutions that generalize the known multicenter extremal solutions, using a particular base metric that introduces a bolt. We analyze the conditions for regularity, and in doing so we show that this family does not include solutions that contain an extremal black hole and a smooth bolt. We determine the constraints that are necessary to obtain smooth horizonless solutions involving a bolt and an arbitrary number of Gibbons-Hawking centers.

  9. 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…

  10. Community Laboratory Testing for Cryptosporidium: Multicenter Study Retesting Public Health Surveillance Stool Samples Positive for Cryptosporidium by Rapid Cartridge Assay with Direct Fluorescent Antibody Testing

    PubMed Central

    Roellig, Dawn M.; Yoder, Jonathan S.; Madison-Antenucci, Susan; Robinson, Trisha J.; Van, Tam T.; Collier, Sarah A.; Boxrud, Dave; Monson, Timothy; Bates, Leigh Ann; Blackstock, Anna J.; Shea, Shari; Larson, Kirsten; Xiao, Lihua; Beach, Michael

    2017-01-01

    Cryptosporidium is a common cause of sporadic diarrheal disease and outbreaks in the United States. Increasingly, immunochromatography-based rapid cartridge assays (RCAs) are providing community laboratories with a quick cryptosporidiosis diagnostic method. In the current study, the Centers for Disease Control and Prevention (CDC), the Association of Public Health Laboratories (APHL), and four state health departments evaluated RCA-positive samples obtained during routine Cryptosporidium testing. All samples underwent “head to head” re-testing using both RCA and direct fluorescence assay (DFA). Community level results from three sites indicated that 54.4% (166/305) of Meridian ImmunoCard STAT! positives and 87.0% (67/77) of Remel Xpect positives were confirmed by DFA. When samples were retested by RCA at state laboratories and compared with DFA, 83.3% (155/186) of Meridian ImmunoCard STAT! positives and 95.2% (60/63) of Remel Xpect positives were confirmed. The percentage of confirmed community results varied by site: Minnesota, 39.0%; New York, 63.9%; and Wisconsin, 72.1%. The percentage of confirmed community results decreased with patient age; 12.5% of community positive tests could be confirmed by DFA for patients 60 years of age or older. The percentage of confirmed results did not differ significantly by sex, storage temperature, time between sample collection and testing, or season. Findings from this study demonstrate a lower confirmation rate of community RCA positives when compared to RCA positives identified at state laboratories. Elucidating the causes of decreased test performance in order to improve overall community laboratory performance of these tests is critical for understanding the epidemiology of cryptosporidiosis in the United States (US). PMID:28085927

  11. Community Laboratory Testing for Cryptosporidium: Multicenter Study Retesting Public Health Surveillance Stool Samples Positive for Cryptosporidium by Rapid Cartridge Assay with Direct Fluorescent Antibody Testing.

    PubMed

    Roellig, Dawn M; Yoder, Jonathan S; Madison-Antenucci, Susan; Robinson, Trisha J; Van, Tam T; Collier, Sarah A; Boxrud, Dave; Monson, Timothy; Bates, Leigh Ann; Blackstock, Anna J; Shea, Shari; Larson, Kirsten; Xiao, Lihua; Beach, Michael

    2017-01-01

    Cryptosporidium is a common cause of sporadic diarrheal disease and outbreaks in the United States. Increasingly, immunochromatography-based rapid cartridge assays (RCAs) are providing community laboratories with a quick cryptosporidiosis diagnostic method. In the current study, the Centers for Disease Control and Prevention (CDC), the Association of Public Health Laboratories (APHL), and four state health departments evaluated RCA-positive samples obtained during routine Cryptosporidium testing. All samples underwent "head to head" re-testing using both RCA and direct fluorescence assay (DFA). Community level results from three sites indicated that 54.4% (166/305) of Meridian ImmunoCard STAT! positives and 87.0% (67/77) of Remel Xpect positives were confirmed by DFA. When samples were retested by RCA at state laboratories and compared with DFA, 83.3% (155/186) of Meridian ImmunoCard STAT! positives and 95.2% (60/63) of Remel Xpect positives were confirmed. The percentage of confirmed community results varied by site: Minnesota, 39.0%; New York, 63.9%; and Wisconsin, 72.1%. The percentage of confirmed community results decreased with patient age; 12.5% of community positive tests could be confirmed by DFA for patients 60 years of age or older. The percentage of confirmed results did not differ significantly by sex, storage temperature, time between sample collection and testing, or season. Findings from this study demonstrate a lower confirmation rate of community RCA positives when compared to RCA positives identified at state laboratories. Elucidating the causes of decreased test performance in order to improve overall community laboratory performance of these tests is critical for understanding the epidemiology of cryptosporidiosis in the United States (US).

  12. Comparison of oncogenic HPV type-specific viral DNA load and E6/E7 mRNA detection in cervical samples: results from a multicenter study.

    PubMed

    Broccolo, Francesco; Fusetti, Lisa; Rosini, Sandra; Caraceni, Donatella; Zappacosta, Roberta; Ciccocioppo, Lucia; Matteoli, Barbara; Halfon, Philippe; Malnati, Mauro S; Ceccherini-Nelli, Luca

    2013-03-01

    High-risk human papillomavirus (HR-HPV) genotype viral load and E6/E7 mRNA detection are proposed as surrogate markers of malignant cervical lesion progression. Currently, the use of commercially available DNA-based or mRNA-based tests is under investigation. In this study, the viral DNA load and E6/E7 mRNA detection of the five most common HR-HPV types detected in cervical cancer worldwide were compared in 308 cervical samples by using in-house type-specific quantitative real-time PCR assays and PreTect HPV-Proofer test, respectively. Sensitivity and negative predictive values were higher for the HPV-DNA assays combined (95.0% and 96.0%, respectively) than the RNA assays (77.0% and 88.0%, respectively); conversely, the mRNA test showed a higher specificity and higher positive predictive value (81.7% and 66.9%, respectively) than the DNA test (58.6% and 52.5%, respectively) for detecting histology-confirmed high-grade cervical intraepithelial neoplasia. A significantly higher association between viral DNA load and severity of disease was observed for HPV 16 and 31 (γ = 0.62 and γ = 0.40, respectively) than for the other HPV types screened. A good degree of association between the two assays was found for detection of HPV 16 (k = 0.83), HPV 18 (k = 0.72), HPV 33 (k = 0.66), and HPV 45 (k = 0.60) but not for HPV 31 (k = 0.24). Sequence analysis in L1 and E6-LCR regions of HPV 31 genotypes showed a high level of intra-type variation. HR-HPV viral DNA load was significantly higher in E6/E7 mRNA positive than negative samples (P < 0.001), except for HPV 31. These findings suggest that transcriptional and replicative activities can coexist within the same sample.

  13. 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

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

    PubMed

    Kalton, Graham; Piesse, Andrea

    2007-04-15

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

  15. 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

  16. 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

  17. 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

  18. Mixed Model with Correction for Case-Control Ascertainment Increases Association Power

    PubMed Central

    Hayeck, Tristan J.; Zaitlen, Noah A.; Loh, Po-Ru; Vilhjalmsson, Bjarni; Pollack, Samuela; Gusev, Alexander; Yang, Jian; Chen, Guo-Bo; Goddard, Michael E.; Visscher, Peter M.; Patterson, Nick; Price, Alkes L.

    2015-01-01

    We introduce a liability-threshold mixed linear model (LTMLM) association statistic for case-control studies and show that it has a well-controlled false-positive rate and more power than existing mixed-model methods for diseases with low prevalence. Existing mixed-model methods suffer a loss in power under case-control ascertainment, but no solution has been proposed. Here, we solve this problem by using a χ2 score statistic computed from posterior mean liabilities (PMLs) under the liability-threshold model. Each individual’s PML is conditional not only on that individual’s case-control status but also on every individual’s case-control status and the genetic relationship matrix (GRM) obtained from the data. The PMLs are estimated with a multivariate Gibbs sampler; the liability-scale phenotypic covariance matrix is based on the GRM, and a heritability parameter is estimated via Haseman-Elston regression on case-control phenotypes and then transformed to the liability scale. In simulations of unrelated individuals, the LTMLM statistic was correctly calibrated and achieved higher power than existing mixed-model methods for diseases with low prevalence, and the magnitude of the improvement depended on sample size and severity of case-control ascertainment. In a Wellcome Trust Case Control Consortium 2 multiple sclerosis dataset with >10,000 samples, LTMLM was correctly calibrated and attained a 4.3% improvement (p = 0.005) in χ2 statistics over existing mixed-model methods at 75 known associated SNPs, consistent with simulations. Larger increases in power are expected at larger sample sizes. In conclusion, case-control studies of diseases with low prevalence can achieve power higher than that in existing mixed-model methods. PMID:25892111

  19. Mixed model with correction for case-control ascertainment increases association power.

    PubMed

    Hayeck, Tristan J; Zaitlen, Noah A; Loh, Po-Ru; Vilhjalmsson, Bjarni; Pollack, Samuela; Gusev, Alexander; Yang, Jian; Chen, Guo-Bo; Goddard, Michael E; Visscher, Peter M; Patterson, Nick; Price, Alkes L

    2015-05-07

    We introduce a liability-threshold mixed linear model (LTMLM) association statistic for case-control studies and show that it has a well-controlled false-positive rate and more power than existing mixed-model methods for diseases with low prevalence. Existing mixed-model methods suffer a loss in power under case-control ascertainment, but no solution has been proposed. Here, we solve this problem by using a χ(2) score statistic computed from posterior mean liabilities (PMLs) under the liability-threshold model. Each individual's PML is conditional not only on that individual's case-control status but also on every individual's case-control status and the genetic relationship matrix (GRM) obtained from the data. The PMLs are estimated with a multivariate Gibbs sampler; the liability-scale phenotypic covariance matrix is based on the GRM, and a heritability parameter is estimated via Haseman-Elston regression on case-control phenotypes and then transformed to the liability scale. In simulations of unrelated individuals, the LTMLM statistic was correctly calibrated and achieved higher power than existing mixed-model methods for diseases with low prevalence, and the magnitude of the improvement depended on sample size and severity of case-control ascertainment. In a Wellcome Trust Case Control Consortium 2 multiple sclerosis dataset with >10,000 samples, LTMLM was correctly calibrated and attained a 4.3% improvement (p = 0.005) in χ(2) statistics over existing mixed-model methods at 75 known associated SNPs, consistent with simulations. Larger increases in power are expected at larger sample sizes. In conclusion, case-control studies of diseases with low prevalence can achieve power higher than that in existing mixed-model methods.

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

    PubMed

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

    1989-05-01

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

  1. PGA: power calculator for case-control genetic association analyses

    PubMed Central

    Menashe, Idan; Rosenberg, Philip S; Chen, Bingshu E

    2008-01-01

    Background Statistical power calculations inform the design and interpretation of genetic association studies, but few programs are tailored to case-control studies of single nucleotide polymorphisms (SNPs) in unrelated subjects. Results We have developed the "Power for Genetic Association analyses" (PGA) package which comprises algorithms and graphical user interfaces for sample size and minimum detectable risk calculations using SNP or haplotype effects under different genetic models and study constrains. The software accounts for linkage disequilibrium and statistical multiple comparisons. The results are presented in graphs or tables and can be printed or exported in standard file formats. Conclusion PGA is user friendly software that can facilitate decision making for association studies of candidate genes, fine-mapping studies, and whole-genome scans. Stand-alone executable files and a Matlab toolbox are available for download at: PMID:18477402

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

    PubMed Central

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

    2011-01-01

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

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

    PubMed

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

    2016-05-19

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

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

    PubMed Central

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

    2012-01-01

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

  5. Population-based case-control association studies.

    PubMed

    Hancock, Dana B; Scott, William K

    2012-07-01

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

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

    PubMed

    Tchetgen Tchetgen, Eric J

    2014-01-01

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

  7. Euclidean supergravity and multi-centered solutions

    NASA Astrophysics Data System (ADS)

    Sabra, W. A.

    2017-04-01

    In ungauged supergravity theories, the no-force condition for BPS states implies the existence of stable static multi-centered solutions. The first solutions to Einstein-Maxwell theory with a positive cosmological constant describing an arbitrary number of charged black holes were found by Kastor and Traschen. Generalisations to five and higher dimensional theories were obtained by London. Multi-centered solutions in gauged supergravity, even with time-dependence allowed, have yet to be constructed. In this letter we construct supersymmetry-preserving multi-centered solutions for the case of D = 5, N = 2 Euclidean gauged supergravity coupled to an arbitrary number of vector multiplets. Higher dimensional Einstein-Maxwell multi-centered solutions are also presented.

  8. 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

    ... National Institutes of Health (NIH) will publish periodic summaries of proposed projects to be submitted to... enrolled at treating hospitals. The annual reporting burden is estimated at 5,302 hours (see Table...

  9. Autologous Skin Cell Spray for Massive Soft Tissue War Injuries: A Prospective, Case-Control, Multicenter Trial

    DTIC Science & Technology

    2014-04-01

    extrapolated to complex traumatic civilian injuries that likewise pose significant issues with available autologous skin coverage (e.g. necrotizing ... fasciitis , motor vehicle accidents or other trauma with associated soft tissue avulsion injuries, etc.). Important data on the mechanism of action

  10. A multicenter case-control study of diagnostic tests for urinary tract infection in the presence of urolithiasis.

    PubMed

    Yilmaz, S; Pekdemir, M; Aksu, N M; Koyuncu, N; Cinar, O; Akpinar, E

    2012-02-01

    Urinary stone disease (USD) alone can cause much morbidity, but when present in conjunction with urinary tract infection, complications and morbidity increase even more. This study investigated the clinical and laboratory findings in patients who had USD with and without infection and evaluated the most suitable diagnostic value for urinary tract infection parameters before urine culture results were available. In a prospective fashion, patients who presented to the emergency department with a complaint of colicky flank pain (with or without hematuria) and who were diagnosed as having urolithiasis with ultrasound were evaluated for 1 year. The gold standard for the diagnosis of urinary tract infection was urine culture. The most suitable diagnostic value for urinary tract infection parameters was determined by receiver operating characteristic (ROC) curves. Logistic regression was used to identify independent variables that predicted a positive urine culture. Of the 192 eligible patients, 177 agreed to participate in the study. Of the clinical and laboratory characteristics analyzed, urine WBC, blood WBC, and fever were significantly different between culture positive and negative patients (p < 0.001, p = 0.04 p = 0.012, respectively). Using ROC curve analysis, pyuria (over 10 WBCs per HPF), fever over 37.9°C, and leucocytosis over 11,300 were the best predictors of a positive culture result. The logistic regression model for leukocytosis >11,300 (OR 2.1), pyuria (OR 2.8), and temperature >37.9°C (OR 3.1) showed a significantly increased risk of having a positive urine culture (correct class 87.9%). While a single physical examination or laboratory finding cannot predict urinary tract infection in USD patients with complete reliability, the presence of pyruria, fever, and leukocytosis significantly increases the odds of a positive urine culture.

  11. Autologous Skin Cell Spray for Massive Soft Tissue War Injuries: A Prospective, Case-Control, Multicenter Trial

    DTIC Science & Technology

    2015-01-01

    experimental group 2; sprayed cells only, no graft). To measure the outcome of specific aim 1, all patients will be assessed with serial photography , range of...all patients will be assessed with serial photography , range of motion testing, functional limb use, and objective measures of gross wound healing

  12. Risk of upper aerodigestive tract cancer and type of alcoholic beverage: a European multicenter case-control study.

    PubMed

    Marron, Manuela; Boffetta, Paolo; Møller, Henrik; Ahrens, Wolfgang; Pohlabeln, Hermann; Benhamou, Simone; Bouchardy, Christine; Lagiou, Pagona; Lagiou, Areti; Slámová, Alena; Schejbalová, Miriam; Merletti, Franco; Richiardi, Lorenzo; Kjaerheim, Kristina; Agudo, Antonio; Castellsague, Xavier; Macfarlane, Tatiana Victorovna; Macfarlane, Gary John; Talamini, Renato; Barzan, Luigi; Canova, Cristina; Simonato, Lorenzo; Biggs, Anne-Marie; Thomson, Peter; Conway, David Ian; McKinney, Patricia Ann; Znaor, Ariana; Healy, Claire Marie; McCartan, Bernard Eugene; Brennan, Paul; Hashibe, Mia

    2012-07-01

    The general relationship between cancers of the upper aerodigestive tract (UADT) and alcohol drinking is established. Nevertheless, it is uncertain whether different types of alcoholic beverages (wine, beer and liquor) carry different UADT cancer risks. Our study included 2,001 UADT cancer cases and 2,125 controls from 14 centres in 10 European countries. All cases were histologically or cytologically confirmed squamous cell carcinomas. Controls were frequency matched by sex, age and centre. Logistic regression models were used to estimate odds ratios (OR) and 95 % confidence intervals (95 %CI) adjusted for age, sex, centre, education level, vegetable and fruit intake, tobacco smoking and alcohol drinking, where appropriate. Risk of beverage-specific alcohol consumption were calculated among 'pure drinker' who consumed one beverage type exclusively, among 'predominant drinkers' who consumed one beverage type to more than 66 % and among 'mixed drinkers' who consumed more than one beverage type to similar proportions. Compared to never drinkers and adjusted for cumulative alcohol consumption, the OR and 95 %CI for wine, beer and liquor drinking, respectively, were 1.24 (0.86, 1.78), 1.54 (1.05, 2.27) and 0.94 (0.53, 1.64) among 'pure drinkers' (p value for heterogeneity across beverage types = 0.306), 1.05 (0.76,1.47), 1.25 (0.87,1.79) and 1.43 (0.95, 2.16) among 'predominant drinkers' (p value = 0.456), and 1.09 (0.79, 1.50), 1.20 (0.88, 1.63) and 1.12 (0.82, 1.53) among 'mixed drinkers' (p value = 0.889). Risk of UADT cancer increased with increasing consumption of all three alcohol beverage types. Our findings underscore the strong and comparable carcinogenic effect of ethanol in wine, beer and liquor on organs of the UADT.

  13. Brazilian multicenter study on prevalence of preterm birth and associated factors

    PubMed Central

    2010-01-01

    Background The occurrence of preterm birth remains a complex public health condition. It is considered the main cause of neonatal morbidity and mortality, resulting in a high likelihood of sequelae in surviving children. With variable incidence in several countries, it has grown markedly in the last decades. In Brazil, however, there are still difficulties to estimate its real occurrence. Therefore, it is essential to establish the prevalence and causes of this condition in order to propose prevention actions. This study intend to collect information from hospitals nationwide on the prevalence of preterm births, their associated socioeconomic and environmental factors, diagnostic and treatment methods resulting from causes such as spontaneous preterm labor, prelabor rupture of membranes, and therapeutic preterm birth, as well as neonatal results. Methods/Design This proposal is a multicenter cross-sectional study plus a nested case-control study, to be implemented in 27 reference obstetric centers in several regions of Brazil (North: 1; Northeast: 10; Central-west: 1; Southeast: 13; South: 2). For the cross sectional component, the participating centers should perform, during a period of six months, a prospective surveillance of all patients hospitalized to give birth, in order to identify preterm birth cases and their main causes. In the first three months of the study, an analysis of the factors associated with preterm birth will also be carried out, comparing women who have preterm birth with those who deliver at term. For the prevalence study, 37,000 births will be evaluated (at term and preterm), corresponding to approximately half the deliveries of all participating centers in 12 months. For the case-control study component, the estimated sample size is 1,055 women in each group (cases and controls). The total number of preterm births estimated to be followed in both components of the study is around 3,600. Data will be collected through a questionnaire all

  14. The association of beta-2 adrenoceptor genotype with short-cervix mediated preterm birth: a case-control study

    PubMed Central

    Miller, Russell; Smiley, Richard; Thom, Elizabeth A.; Grobman, William A.; Iams, Jay D.; Mercer, Brian M.; Saade, George; Tita, Alan T.; Reddy, Uma M.; Rouse, Dwight J.; Sorokin, Yoram; Blackwell, Sean C.; Esplin, M. Sean; Tolosa, Jorge E.; Caritis, Steve N.

    2014-01-01

    OBJECTIVE To determine if β2-adrenoceptor (β2AR) genotype is associated with shortening of the cervix or with preterm birth (PTB) risk among subjects with a short cervix in the second trimester. DESIGN A case-control ancillary study to a multicenter randomized controlled trial. SETTING 14 participating centers of the Maternal-Fetal Medicine Units Network of the Eunice Kennedy Shriver National Institute of Child Health and Human Development. POPULATION 439 subjects, including 315 with short cervix and 124 with normal cervical length. METHODS Nulliparous women with cervical length <30mm upon 16–22 week transvaginal sonogram and controls frequency-matched for race/ethnicity with cervical lengths ≥40mm were studied. β2AR genotype was determined at positions encoding for amino acid residues 16 and 27. MAIN OUTCOME MEASURES Genotype distributions were compared between case and control groups. Within the short cervix group, pregnancy outcomes were compared by genotype, with a primary outcome of PTB <37 weeks. RESULTS Genotype data were available at position 16 for 433 subjects and position 27 for 437. Using a recessive model testing for association between short cervix and genotype, and adjusted for ethnicity, there was no statistical difference between cases and controls for Arg16 homozygosity (OR 0.7, 95% CI 0.4–1.3) or Gln27 homozygosity (OR 0.9, 95% CI 0.3–2.7). Among cases, Arg16 homozygosity was not associated with protection from PTB or spontaneous PTB. Gln27 homozygosity was not associated with PTB risk, although sample size was limited. CONCLUSIONS β2AR genotype does not seem to be associated with short cervical length or with PTB following the second-trimester identification of a short cervix. Influences on PTB associated with β2AR genotype do not appear to involve a short cervix pathway. TWEETABLE ABSTRACT β2AR gene variation was not associated with short cervix or with PTB risk following a short cervix diagnosis. PMID:25600430

  15. 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

  16. 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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2006-09-01

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

  19. 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.

  20. A modular informatics platform for effective support of collaborative and multicenter studies in cardiology.

    PubMed

    Marinelli, Martina; Positano, Vincenzo; Lorenzoni, Valentina; Caselli, Chiara; Mangione, Maurizio; Marcheschi, Paolo; Puzzuoli, Stefano; Esposito, Natalia; L'Abbate, Giuseppe Andrea; Neglia, Danilo

    2016-12-01

    Collaborative and multicenter studies permit a large number of patients to be enrolled within a reasonable time and providing the opportunity to collect different data. Informatics platforms play an important role in management, storage, and exchange of data between the participants involved in the study. In this article, we describe a modular informatics platform designed and developed to support collaborative and multicenter studies in cardiology. In each developed module, data management is implemented following local defined protocols. The modular characteristic of the developed platform allows independent transfer of different kinds of data, such as biological samples, imaging raw data, and patients' digital information. Moreover, it offers safe central storage of the data collected during the study. The developed platform was successfully tested during a European collaborative and multicenter study, focused on evaluating multimodal non-invasive imaging to diagnose and characterize ischemic heart disease.

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

    PubMed

    Tweel, Ingeborg van der; Schipper, Maria

    2004-12-30

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

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

    PubMed

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

    2017-03-28

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

  3. The Global Enteric Multicenter Study (GEMS): Impetus, Rationale, and Genesis

    PubMed Central

    Levine, Myron M.; Kotloff, Karen L.; Nataro, James P.; Muhsen, Khitam

    2012-01-01

    Diarrheal disease remains one of the top 2 causes of young child mortality in the developing world. Whereas improvements in water/sanitation infrastructure and hygiene can diminish transmission of enteric pathogens, vaccines can also hasten the decline of diarrheal disease morbidity and mortality. From 1980 through approximately 2004, various case/control and small cohort studies were undertaken to address the etiology of pediatric diarrhea in developing countries. Many studies had methodological limitations and came to divergent conclusions, making it difficult to prioritize the relative importance of different pathogens. Consequently, in the first years of the millennium there was no consensus on what diarrheal disease vaccines should be developed or implemented; however, there was consensus on the need for a well-designed study to obtain information on the etiology and burden of more severe forms of diarrheal disease to guide global investment and implementation decisions. Accordingly, the Global Enteric Multicenter Study (GEMS) was designed to overcome drawbacks of earlier studies and determine the etiology and population-based burden of pediatric diarrheal disease. GEMS, which includes one of the largest case/control studies of an infectious disease syndrome ever undertaken (target approximately 12 600 analyzable cases and 12 600 controls), was rolled out in 4 sites in sub-Saharan Africa (Gambia, Kenya, Mali, Mozambique) and 3 in South Asia (Bangladesh, India, Pakistan), with each site linked to a population under demographic surveillance (total approximately 467 000 child years of observation among children <5 years of age). GEMS data will guide investment and help prioritize strategies to mitigate the morbidity and mortality of pediatric diarrheal disease. PMID:23169934

  4. The Global Enteric Multicenter Study (GEMS): impetus, rationale, and genesis.

    PubMed

    Levine, Myron M; Kotloff, Karen L; Nataro, James P; Muhsen, Khitam

    2012-12-01

    Diarrheal disease remains one of the top 2 causes of young child mortality in the developing world. Whereas improvements in water/sanitation infrastructure and hygiene can diminish transmission of enteric pathogens, vaccines can also hasten the decline of diarrheal disease morbidity and mortality. From 1980 through approximately 2004, various case/control and small cohort studies were undertaken to address the etiology of pediatric diarrhea in developing countries. Many studies had methodological limitations and came to divergent conclusions, making it difficult to prioritize the relative importance of different pathogens. Consequently, in the first years of the millennium there was no consensus on what diarrheal disease vaccines should be developed or implemented; however, there was consensus on the need for a well-designed study to obtain information on the etiology and burden of more severe forms of diarrheal disease to guide global investment and implementation decisions. Accordingly, the Global Enteric Multicenter Study (GEMS) was designed to overcome drawbacks of earlier studies and determine the etiology and population-based burden of pediatric diarrheal disease. GEMS, which includes one of the largest case/control studies of an infectious disease syndrome ever undertaken (target approximately 12,600 analyzable cases and 12,600 controls), was rolled out in 4 sites in sub-Saharan Africa (Gambia, Kenya, Mali, Mozambique) and 3 in South Asia (Bangladesh, India, Pakistan), with each site linked to a population under demographic surveillance (total approximately 467,000 child years of observation among children <5 years of age). GEMS data will guide investment and help prioritize strategies to mitigate the morbidity and mortality of pediatric diarrheal disease.

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

    PubMed

    Kim, Ryung S; Kaplan, Robert C

    2014-10-30

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

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

    PubMed

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

    2015-04-01

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

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

    PubMed

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

    2011-12-01

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

  8. Estimating marginal causal effects in a secondary analysis of case-control data.

    PubMed

    Persson, Emma; Waernbaum, Ingeborg; Lind, Torbjörn

    2017-03-09

    When an initial case-control study is performed, data can be used in a secondary analysis to evaluate the effect of the case-defining event on later outcomes. In this paper, we study the example in which the role of the event is changed from a response variable to a treatment of interest. If the aim is to estimate marginal effects, such as average effects in the population, the sampling scheme needs to be adjusted for. We study estimators of the average effect of the treatment in a secondary analysis of matched and unmatched case-control data where the probability of being a case is known. For a general class of estimators, we show the components of the bias resulting from ignoring the sampling scheme and demonstrate a design-weighted matching estimator of the average causal effect. In simulations, the finite sample properties of the design-weighted matching estimator are studied. Using a Swedish diabetes incidence register with a matched case-control design, we study the effect of childhood onset diabetes on the use of antidepressant medication as an adult. Copyright © 2017 John Wiley & Sons, Ltd.

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

    PubMed

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

    2013-06-01

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

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

    PubMed

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

    2011-09-01

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

  11. 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: |

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

    PubMed

    Havelaar, Arie H; Swart, Arno

    2016-12-01

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

  13. A case-control study of dietary salt intake in pediatric-onset multiple sclerosis

    PubMed Central

    McDonald, Jamie; Graves, Jennifer; Waldman, Amy; Lotze, Timothy; Schreiner, Teri; Belman, Anita; Greenberg, Benjamin; Weinstock-Guttman, Bianca; Aaen, Gregory; Tillema, Jan-Mendelt; Hart, Janace; Lulu, Sabeen; Ness, Jayne; Harris, Yolanda; Rubin, Jennifer; Candee, Meghan; Krupp, Lauren B.; Gorman, Mark; Benson, Leslie; Rodriguez, Moses; Chitnis, Tanuja; Mar, Soe; Barcellos, Lisa F.; Laraia, Barbara; Rose, John; Roalstad, Shelly; Simmons, Timothy; Casper, T. Charles; Waubant, Emmanuelle

    2016-01-01

    Background High salt intake may be associated with pro-inflammatory changes in the immune response, and increased clinical and MRI activity in adults with relapsing-remitting multiple sclerosis. Objective We sought to determine if dietary salt intake is associated with pediatric-onset MS risk in a multicenter, case-control study. Methods Pediatric-onset CIS/MS cases within four years of onset and controls less than 22 years old recruited from 14 pediatric-MS centers were studied. Dietary sodium intake was assessed using the validated Block Kids Food Screener (NutritionQuest). Sodium intake, excess sodium, and sodium terciles were compared between cases and controls. Logistic regression models were adjusted for age, gender, ethnicity, body mass index, and socioeconomic status. Results Among 170 cases (mean age=15.2±3.5) and 331 controls (mean age=14.0±3.7), no significant difference in unadjusted mean sodium intake was found between cases (2044 mg/d) and controls (2030 mg/d, p=0.99). The proportion of subjects consuming excess sodium, based on the adequate intake for age and gender, was similar between cases and controls (65% versus 69%, p=0.34). There were no increased odds of higher sodium intake among cases as compared to controls (for each 100 mg/d increase in sodium, OR=1.00, 95% CI 0.98, 1.02; p=0.93, for excess sodium intake, OR=1.05, 95% CI 0.67, 1.64; p=0.84). Conclusions Our results show no strong association between dietary salt intake and pediatric-onset MS risk, suggesting that salt intake may not play a prominent role in susceptibility to MS in children. PMID:27063630

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2000-01-01

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

  16. CAPL: a novel association test using case-control and family data and accounting for population stratification.

    PubMed

    Chung, Ren-Hua; Schmidt, Michael A; Morris, Richard W; Martin, Eden R

    2010-11-01

    The recent successes of GWAS based on large sample sizes motivate combining independent datasets to obtain larger sample sizes and thereby increase statistical power. Analysis methods that can accommodate different study designs, such as family-based and case-control designs, are of general interest. However, population stratification can cause spurious association for population-based association analyses. For family-based association analysis that infers missing parental genotypes based on the allele frequencies estimated in the entire sample, the parental mating-type probabilities may not be correctly estimated in the presence of population stratification. Therefore, any approach to combining family and case-control data should also properly account for population stratification. Although several methods have been proposed to accommodate family-based and case-control data, all have restrictions. Most of them require sampling a homogeneous population, which may not be a reasonable assumption for data from a large consortium. One of the methods, FamCC, can account for population stratification and uses nuclear families with arbitrary number of siblings but requires parental genotype data, which are often unavailable for late-onset diseases. We extended the family-based test, Association in the Presence of Linkage (APL), to combine family and case-control data (CAPL). CAPL can accommodate case-control data and families with multiple affected siblings and missing parents in the presence of population stratification. We used simulations to demonstrate that CAPL is a valid test either in a homogeneous population or in the presence of population stratification. We also showed that CAPL can have more power than other methods that combine family and case-control data.

  17. 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

  18. Exposure enriched case-control (EECC) design for the assessment of gene-environment interaction

    PubMed Central

    Carroll, Raymond J.; Diao, Nancy; Christiani, David C.; Ryan, Louise M.

    2016-01-01

    Genetic susceptibility and environmental exposure both play an important role in the aetiology of many diseases. Case-control studies are often the first choice to explore the joint influence of genetic and environmental factors on the risk of developing a rare disease. In practice, however, such studies may have limited power, especially when susceptibility genes are rare and exposure distributions are highly skewed. We propose a variant of the classical case-control study, the exposure enriched case-control (EECC) design, where not only cases, but also high (or low) exposed individuals are oversampled, depending on the skewness of the exposure distribution. Of course, a traditional logistic regression model is no longer valid and results in biased parameter estimation. We show that addition of a simple covariate to the regression model removes this bias and yields reliable estimates of main and interaction effects of interest. We also discuss optimal design, showing that judicious over-sampling of high/low exposed individuals can boost study power considerably. We illustrate our results using data from a study involving arsenic exposure and detoxification genes in Bangladesh. PMID:27313007

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

    PubMed

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

    2017-01-18

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

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

    PubMed

    Borgan, Ørnulf; Zhang, Ying

    2015-09-01

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

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

    PubMed

    Silva Ayçaguer, L C

    2004-01-01

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

  2. 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…

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

    PubMed

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

    1991-01-01

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

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

    PubMed

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

    1988-01-01

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

  5. 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.

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

    PubMed

    Borgan, Ørnulf; Keogh, Ruth

    2015-10-01

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

  7. 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.

  8. KRAS mutations in blood circulating cell-free DNA: a pancreatic cancer case-control

    PubMed Central

    Le Calvez-Kelm, Florence; Foll, Matthieu; Wozniak, Magdalena B.; Delhomme, Tiffany M.; Durand, Geoffroy; Chopard, Priscilia; Pertesi, Maroulio; Fabianova, Eleonora; Adamcakova, Zora; Holcatova, Ivana; Foretova, Lenka; Janout, Vladimir; Vallee, Maxime P.; Rinaldi, Sabina; Brennan, Paul; McKay, James D.; Byrnes, Graham B.; Scelo, Ghislaine

    2016-01-01

    The utility of KRAS mutations in plasma circulating cell-free DNA (cfDNA) samples as non-invasive biomarkers for the detection of pancreatic cancer has never been evaluated in a large case-control series. We applied a KRAS amplicon-based deep sequencing strategy combined with analytical pipeline specifically designed for the detection of low-abundance mutations to screen plasma samples of 437 pancreatic cancer cases, 141 chronic pancreatitis subjects, and 394 healthy controls. We detected mutations in 21.1% (N=92) of cases, of whom 82 (89.1%) carried at least one mutation at hotspot codons 12, 13 or 61, with mutant allelic fractions from 0.08% to 79%. Advanced stages were associated with an increased proportion of detection, with KRAS cfDNA mutations detected in 10.3%, 17,5% and 33.3% of cases with local, regional and systemic stages, respectively. We also detected KRAS cfDNA mutations in 3.7% (N=14) of healthy controls and in 4.3% (N=6) of subjects with chronic pancreatitis, but at significantly lower allelic fractions than in cases. Combining cfDNA KRAS mutations and CA19-9 plasma levels on a limited set of case-control samples did not improve the overall performance of the biomarkers as compared to CA19-9 alone. Whether the limited sensitivity and specificity observed in our series of KRAS mutations in plasma cfDNA as biomarkers for pancreatic cancer detection are attributable to methodological limitations or to the biology of cfDNA should be further assessed in large case-control series. PMID:27705932

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

    PubMed

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

    2015-09-01

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

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

    PubMed Central

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

    1987-01-01

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

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

    PubMed

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

    1987-07-01

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

  12. A Bayesian Approach to Multicenter Trials and Metaanalysis.

    ERIC Educational Resources Information Center

    Berry, Donald A.

    The use of a Bayesian approach in evaluating data from clinical trials with many treatment centers and from many studies is discussed. The main distinction between a metaanalysis and an analysis of a multicenter trial is that different studies may have very different designs, while the centers in a multicenter trial usually follow the same…

  13. 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.

  14. 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

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

    PubMed

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

    2012-12-01

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

  16. 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

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

    PubMed Central

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

    2000-01-01

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


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

  18. Case-control study of respiratory cancer and employment

    SciTech Connect

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

    1984-04-01

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

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

    PubMed Central

    Kar, Bikash Ranjan; Panda, Maitreyee

    2016-01-01

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

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

    PubMed

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

    1990-11-01

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

  1. 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.

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

    PubMed Central

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

    1990-01-01

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

  3. 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

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

    PubMed

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

    1987-01-01

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

  5. 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

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

    PubMed

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

    2008-11-01

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

  7. 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

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

    PubMed

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

    2010-07-01

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

  9. Cartilage Loss Occurs in the Same Subregions as Subchondral Bone Attrition: A Within-Knee Subregion-Matched Approach From the Multicenter Osteoarthritis Study

    PubMed Central

    Neogi, T.; Felson, D.; Niu, J.; Lynch, J.; Nevitt, M.; Guermazi, A.; Roemer, F.; Lewis, C. E.; Wallace, B.; Zhang, Y.

    2009-01-01

    Objective By magnetic resonance imaging (MRI), subchondral bone attrition (SBA) can be seen in early osteoarthritis (OA), but the significance of this is unknown. We therefore evaluated whether SBA was associated with cartilage loss within the same subregion of the knee. Methods The Multicenter Osteoarthritis Study is a cohort of individuals who have or are at high risk for knee OA. At baseline and 30 months, participants’ knee MRIs were graded using the Whole-Organ Magnetic Resonance Imaging Score in the 10 subregions of the tibiofemoral joint for cartilage morphology and SBA. We conducted analyses within a knee to eliminate between-person confounding, using an M:N (cases:controls) matched case–control approach with the 10 subregions of a person’s knee forming a matched set. Cases within a knee were defined as subregions with cartilage loss, while controls were subregions in that same knee without cartilage loss. We evaluated the association of cartilage loss over 30 months with the presence of baseline SBA in the same subregion within that knee using conditional logistic regression. Results SBA was associated with an odds ratio of 7.5 (95% confidence interval 5.6 –9.9, P < 0.0001) for cartilage loss in the same subregion compared with subregions without any baseline SBA in our sample of 459 knees from participants, 64% of whom were women, with a mean age of 63 years and a mean body mass index of 30.5 kg/m2. Conclusion SBA is strongly associated with cartilage loss within the same subregion of a knee. SBA may directly influence overlying cartilage loss or serve as a marker of an area undergoing great compressive stress and in which cartilage loss is inevitable. PMID:19877101

  10. 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

  11. Multicenter Epidemiological Studies of Atherosclerosis Imaging

    PubMed Central

    Liu, Songtao; Bluemke, David A.

    2011-01-01

    Cardiovascular disease is the leading course of death and disability. Conventional cardiac risk factors do not fully explain the level of cardiovascular risk, incidence of coronary artery disease, and coronary events. Risk stratification and therapy based solely on these conventional risk factors may overlook a population who would benefit from lifestyle and risk factor modification. Thus, research has recently focused on improving risk assessment with new tools in an effort to better identify subjects at highest risk and in need of aggressive management. Cardiovascular imaging, both in coronary and extracoronary arterial beds, has proven to be very helpful in this regard. In this article, we review the current literature from multicenter epidemiology studies on the utility of noninvasive imaging modalities for risk stratification in the context of conventional risk factor evaluation. PMID:20805734

  12. Multicenter Clinical Trial of Keratin Biomaterial for Peripheral Nerve Regeneration

    DTIC Science & Technology

    2015-12-01

    Award Number: W81XWH-10-1-0894 TITLE: Multicenter Clinical Trial of Keratin Biomaterial for Peripheral Nerve Regeneration PRINCIPAL...DATES COVERED 15Sep2010 - 14Sep2015 4. TITLE AND SUBTITLE Multicenter Clinical Trial of Keratin Biomaterial for 5a. CONTRACT NUMBER W81XWH-10-1-0894... clinical trial was to be initiated as soon as the FDA provided an IND for the keratin biomaterial hydrogel. However, due to delays in the FDA approval

  13. Multicenter Clinical Trial of Keratin Biomaterial for Peripheral Nerve Regeneration

    DTIC Science & Technology

    2014-10-01

    AD_________________ Award Number: W81XWH-10-1-0894 TITLE: Multicenter Clinical Trial of Keratin Biomaterial for Peripheral Nerve Regeneration...DATES COVERED 15 Sep 2013 - 14 Sep 2014 4. TITLE AND SUBTITLE Multicenter Clinical Trial of Keratin Biomaterial for 5a. CONTRACT NUMBER Peripheral...has developed a keratin biomaterial hydrogel that can be used as luminal filler in nerve guidance conduits to facilitate nerve regeneration

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

    PubMed

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

    2017-04-01

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

  15. 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

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

    PubMed

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

    2016-03-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2001-08-01

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

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

    PubMed Central

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

    2006-01-01

    Background Several studies have suggested an association between periodontal disease and prematurity but this finding has not been consistently observed. Methods Case control study. Cases (n = 50) were women who had delivered after spontaneous preterm labor at <35 weeks gestation. Two groups of controls (n = 101) were recruited: women who were undelivered but at a preterm gestation and women who delivered at term. A standard, clinical, periodontal examination was performed and gingival crevicular fluid was obtained from standardized locations and tested for neutrophil elastase along with the bacterial enzymes gingipain and dipeptidylpeptidase. Data were analyzed with Fisher's exact tests, ANOVA and multivariate logistic regression. Results There was no difference in the proportion of sites with significant attachment loss (≥3 mm): Cases-3.2%, Controls-2.2% p = 0.21. The gingival crevicular fluid concentrations of elastase and gingipain were elevated in cases vs. controls 238.8 uU/ul vs. 159.6 uU/ul p = .007 and 2.70 uU/ul vs. 1.56 uU/ul p = .001. On multivariate analysis, the mean log concentration of elastase, but not of gingipain, remained a significant predictor of preterm labor p = .0.015. Conclusion We found no evidence that clinical periodontal disease is associated with spontaneous preterm birth. Elevated gingival crevicular fluid levels of elastase were associated with preterm birth but further research is needed before this can be assumed to be a causal relationship. PMID:16848912

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

    PubMed Central

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

    1994-01-01

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

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

    PubMed

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

    2016-03-01

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

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

    PubMed

    Keogh, Ruth H; White, Ian R

    2013-10-15

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed

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

    2012-11-01

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

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

    PubMed

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

    2006-12-15

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

  6. Weighted pseudolikelihood for SNP set analysis with multiple secondary outcomes in case-control genetic association studies.

    PubMed

    Sofer, Tamar; Schifano, Elizabeth D; Christiani, David C; Lin, Xihong

    2017-03-27

    We propose a weighted pseudolikelihood method for analyzing the association of a SNP set, example, SNPs in a gene or a genetic pathway or network, with multiple secondary phenotypes in case-control genetic association studies. To boost analysis power, we assume that the SNP-specific effects are shared across all secondary phenotypes using a scaled mean model. We estimate regression parameters using Inverse Probability Weighted (IPW) estimating equations obtained from the weighted pseudolikelihood, which accounts for case-control sampling to prevent potential ascertainment bias. To test the effect of a SNP set, we propose a weighted variance component pseudo-score test. We also propose a penalized IPW pseudolikelihood method for selecting a subset of SNPs that are associated with the multiple secondary phenotypes. We show that the proposed variable selection procedure has the oracle properties and is robust to misspecification of the correlation structure among secondary phenotypes. We select the tuning parameter using a weighted Bayesian Information-like Criterion (wBIC). We evaluate the finite sample performance of the proposed methods via simulations, and illustrate the methods by the analysis of the multiple secondary smoking behavior outcomes in a lung cancer case-control genetic association study.

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

    PubMed

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

    2009-06-01

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

  8. 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

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

    PubMed

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

    2004-03-01

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

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

    PubMed

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

    2011-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2004-07-01

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

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

    PubMed Central

    Alvarado-Esquivel, Cosme

    2013-01-01

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

  14. 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

  15. 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

  16. Improved survival among ICU-hospitalized patients with community-acquired pneumonia by unidentified organisms: a multicenter case-control study.

    PubMed

    Rello, J; Diaz, E; Mañez, R; Sole-Violan, J; Valles, J; Vidaur, L; Zaragoza, R; Gattarello, S

    2017-01-01

    A retrospective analysis from prospectively collected data was conducted in intensive care units (ICUs) at 33 hospitals in Europe comparing the trend in ICU survival among adults with severe community-acquired pneumonia (CAP) due to unknown organisms from 2000 to 2015. The secondary objective was to establish whether changes in antibiotic policies were associated with different outcomes. ICU mortality decreased (p = 0.02) from 26.9 % in the first study period (2000-2002) to 15.7 % in the second period (2008-2015). Demographic data and clinical severity at admission were comparable between groups, except for age over 65 years and incidence of cardiomyopathy. Over time, patients received higher rates of combination therapy (94.3 vs. 77.2 %; p < 0.01) and early (<3 h) antibiotic delivery (72.9 vs. 50.3 %; p < 0.01); likewise, the 2008-2015 group was more likely to receive adequate antibiotic prescription [as defined by the Infectious Diseases Society of America/American Thoracic Society (IDSA/ATS) guidelines] than the 2000-2002 group (70.7 vs. 48.2 %; p < 0.01). Multivariate analysis showed an independent association between decreased ICU mortality and early (<3 h) antibiotic administration [odds ratio (OR) 3.48 [1.70-7.15], p < 0.01] or adequate antibiotic prescription according to guidelines (OR 2.22 [1.11-4.43], p = 0.02). In conclusion, our findings suggest that ICU mortality in severe CAP due to unidentified organisms has decreased in the last 15 years. Several changes in management and better compliance with guidelines over time were associated with increased survival.

  17. A multicenter case-control study on screening of single nucleotide polymorphisms in estrogen-metabolizing enzymes and susceptibility to uterine leiomyoma in han chinese.

    PubMed

    Shen, Yang; Ren, Mu-Lan; Xu, Jie; Xu, Qian; Ding, Yi-Qian; Wu, Zhi-Cong; Zhang, Hai-Bao; Huang, Xian-Xia; Cai, Yun-Lang

    2014-01-01

    Uterine leiomyoma (UL) is an estrogen-responsive benign tumor in the female reproductive system and the main risk of hysterectomy for women. However, gene polymorphism of estrogen-metabolizing enzymes may lead to the different susceptibility to UL. We detected 10 single mucleotide polymorphisms in three key estrogen metabolite enzymes (COMT, CYP1A1, CYP1B1) in a Chinese Han population consisting of 800 patients and 800 healthy women from five different medical centers. The genetic polymorphism of rs3087869 (IVS1+2329C>T) (OR 3.200, 95% CI 1.614-6.345) and rs4680 (Val158Met) (OR 5.675, 95% CI 2.696-11.942) loci on COMT, rs1048943 (Ile462Val) (OR 4.629, 95% CI 2.216-9.672) and rs4646422 (Gly45Asp) (OR 3.240, 95% CI 1.624-6.461) loci on CYP1A1 and rs1065827 (Ala119Ser) (OR 5.635, 95% CI 2.990-10.619) locus on CYP1B1 were the risk factors to UL development and rs1056836 (Leu432Val) (OR 0.188, 95% CI 0.061-0.575) locus on CYB1B1 may be the protective factor to UL. The results provide a theoretical basis for genetic screening and early intervention to UL-susceptible populations.

  18. 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.

  19. Case-control study for colorectal cancer genetic susceptibility in EPICOLON: previously identified variants and mucins

    PubMed Central

    2011-01-01

    Background Colorectal cancer (CRC) is the second leading cause of cancer death in developed countries. Familial aggregation in CRC is also important outside syndromic forms and, in this case, a polygenic model with several common low-penetrance alleles contributing to CRC genetic predisposition could be hypothesized. Mucins and GALNTs (N-acetylgalactosaminyltransferase) are interesting candidates for CRC genetic susceptibility and have not been previously evaluated. We present results for ten genetic variants linked to CRC risk in previous studies (previously identified category) and 18 selected variants from the mucin gene family in a case-control association study from the Spanish EPICOLON consortium. Methods CRC cases and matched controls were from EPICOLON, a prospective, multicenter, nationwide Spanish initiative, comprised of two independent stages. Stage 1 corresponded to 515 CRC cases and 515 controls, whereas stage 2 consisted of 901 CRC cases and 909 controls. Also, an independent cohort of 549 CRC cases and 599 controls outside EPICOLON was available for additional replication. Genotyping was performed for ten previously identified SNPs in ADH1C, APC, CCDN1, IL6, IL8, IRS1, MTHFR, PPARG, VDR and ARL11, and 18 selected variants in the mucin gene family. Results None of the 28 SNPs analyzed in our study was found to be associated with CRC risk. Although four SNPs were significant with a P-value < 0.05 in EPICOLON stage 1 [rs698 in ADH1C (OR = 1.63, 95% CI = 1.06-2.50, P-value = 0.02, recessive), rs1800795 in IL6 (OR = 1.62, 95% CI = 1.10-2.37, P-value = 0.01, recessive), rs3803185 in ARL11 (OR = 1.58, 95% CI = 1.17-2.15, P-value = 0.007, codominant), and rs2102302 in GALNTL2 (OR = 1.20, 95% CI = 1.00-1.44, P-value = 0.04, log-additive 0, 1, 2 alleles], only rs3803185 achieved statistical significance in EPICOLON stage 2 (OR = 1.34, 95% CI = 1.06-1.69, P-value = 0.01, recessive). In the joint analysis for both stages, results were only significant for rs

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

    PubMed

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

    2004-02-01

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

  1. 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

  2. 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

  3. Multicenter Quality Control of Hepatitis C Virus Protease Inhibitor Resistance Genotyping

    PubMed Central

    Larrat, Sylvie; Laperche, Syria; Le Guillou-Guillemette, Hélène; Legrand-Abravanel, Florence; Bouchardeau, Françoise; Pivert, Adeline; Henquell, Cécile; Mirand, Audrey; André-Garnier, Elisabeth; Giordanengo, Valérie; Lagathu, Gisèle; Thibault, Vincent; Scholtes, Caroline; Schvoerer, Evelyne; Gaudy-Graffin, Catherine; Maylin, Sarah; Trimoulet, Pascale; Brochot, Etienne; Hantz, Sébastien; Gozlan, Joël; Roque-Afonso, Anne-Marie; Soussan, Patrick; Plantier, Jean-Christophe; Charpentier, Charlotte; Chevaliez, Stéphane; Colson, Philippe; Mackiewicz, Vincent; Aguilera, Lina; Rosec, Sylvain; Gouriou, Stéphanie; Magnat, Nelly; Lunel-Fabiani, Françoise; Izopet, Jacques; Morand, Patrice; Payan, Christopher; Pawlotsky, Jean-Michel

    2013-01-01

    Hepatitis C virus (HCV) protease inhibitor resistance-associated substitutions are selected during triple-therapy breakthrough. This multicenter quality control study evaluated the expertise of 23 French laboratories in HCV protease inhibitor resistance genotyping. A panel of 12 well-defined blinded samples comprising two wild-type HCV strains, nine transcripts from synthetic NS3 mutant samples or from clinical strains, and one HCV RNA-negative sample was provided to the participating laboratories. The results showed that any laboratory with expertise in sequencing techniques should be able to provide reliable HCV protease inhibitor resistance genotyping. Only a 0.7% error rate was reported for the amino acid sites studied. The accuracy of substitution identification ranged from 75% to 100%, depending on the laboratory. Incorrect results were mainly related to the methodology used. The results could be improved by changing the primers and modifying the process in order to avoid cross-contamination. This study underlines the value of quality control programs for viral resistance genotyping, which is required prior to launching observational collaborative multicenter studies on HCV resistance to direct-acting antiviral agents. PMID:23426922

  4. Multicenter quality control of hepatitis C virus protease inhibitor resistance genotyping.

    PubMed

    Vallet, Sophie; Larrat, Sylvie; Laperche, Syria; Le Guillou-Guillemette, Hélène; Legrand-Abravanel, Florence; Bouchardeau, Françoise; Pivert, Adeline; Henquell, Cécile; Mirand, Audrey; André-Garnier, Elisabeth; Giordanengo, Valérie; Lagathu, Gisèle; Thibault, Vincent; Scholtes, Caroline; Schvoerer, Evelyne; Gaudy-Graffin, Catherine; Maylin, Sarah; Trimoulet, Pascale; Brochot, Etienne; Hantz, Sébastien; Gozlan, Joël; Roque-Afonso, Anne-Marie; Soussan, Patrick; Plantier, Jean-Christophe; Charpentier, Charlotte; Chevaliez, Stéphane; Colson, Philippe; Mackiewicz, Vincent; Aguilera, Lina; Rosec, Sylvain; Gouriou, Stéphanie; Magnat, Nelly; Lunel-Fabiani, Françoise; Izopet, Jacques; Morand, Patrice; Payan, Christopher; Pawlotsky, Jean-Michel

    2013-05-01

    Hepatitis C virus (HCV) protease inhibitor resistance-associated substitutions are selected during triple-therapy breakthrough. This multicenter quality control study evaluated the expertise of 23 French laboratories in HCV protease inhibitor resistance genotyping. A panel of 12 well-defined blinded samples comprising two wild-type HCV strains, nine transcripts from synthetic NS3 mutant samples or from clinical strains, and one HCV RNA-negative sample was provided to the participating laboratories. The results showed that any laboratory with expertise in sequencing techniques should be able to provide reliable HCV protease inhibitor resistance genotyping. Only a 0.7% error rate was reported for the amino acid sites studied. The accuracy of substitution identification ranged from 75% to 100%, depending on the laboratory. Incorrect results were mainly related to the methodology used. The results could be improved by changing the primers and modifying the process in order to avoid cross-contamination. This study underlines the value of quality control programs for viral resistance genotyping, which is required prior to launching observational collaborative multicenter studies on HCV resistance to direct-acting antiviral agents.

  5. Acute necrotizing pancreatitis: a multicenter study.

    PubMed

    Fernández-Cruz, L; Navarro, S; Valderrama, R; Sáenz, A; Guarner, L; Aparisi, L; Espi, A; Jaurietta, E; Marruecos, L; Gener, J

    1994-04-01

    A multicenter study of acute necrotizing pancreatitis (ANP) classified in accordance with the Balthazar criteria (grades D and E), has been performed in 12 teaching hospitals. A total of 233 patients were reviewed, and the mortality rate was 26.6%. The most common etiology was biliary pancreatitis (45.5%). Among the complications, shock, renal insufficiency, pulmonary insufficiency and hemorrhagic gastritis were associated with a mortality rate of 51-66%. Diffuse fluid collections were associated with a higher mortality rate (26.8%) than localized fluid collections (14.5%). In 106 patients with gallstone pancreatitis, early surgery was performed in 17, and 5 patients (29.4%) died. No mortality was observed in 32 patients with delayed surgery. Sphincterotomy was performed in 13 patients, and 4 (30.7%) died. Early surgery (necrosectomy and closed peritoneal lavage) was undertaken in 75 patients, with a mortality rate of 39%. In conclusion, the morbidity and mortality rates of ANP can be improved with proper monitoring, adequate supportive care and the judicious use of surgery based on clinical and morphological findings.

  6. Wandering spleen in children: multicenter retrospective study.

    PubMed

    Fiquet-Francois, Caroline; Belouadah, Mohamed; Ludot, Hugues; Defauw, Benoit; Mcheik, Jiad Noel; Bonnet, Jean Paul; Kanmegne, Charly Udozen; Weil, Dominique; Coupry, Lionel; Fremont, Benjamin; Becmeur, Francois; Lacreuse, Isabelle; Montupet, Philippe; Rahal, Eliane; Botto, Nathalie; Cheikhelard, Alaa; Sarnacki, Sabine; Petit, Thierry; Poli Merol, Marie Laurence

    2010-07-01

    Wandering spleen in children is a rare condition. The diagnosis is difficult, and any delay can cause splenic ischemia. An epidemiologic, semiological, and surgical diagnosis questionnaire on incidence of wandering spleen in children was sent to several French surgical teams. We report the results of this multicenter retrospective study. Fourteen cases (6 girls, 8 boys) were reported between 1984 and 2009; the age range varies between 1-day-old and 15 years; 86% were seen in the emergency department. Ninety-three percent had diffuse abdominal pain. For 57% of the cases, it was their first symptomatic episode of this type. No diagnosis was established based on the clinical results alone. All patients had presurgical imaging diagnosis. Open surgery was performed on 64% cases. Forty-three had splenectomy for splenic ischemia. Thirty-six percent had splenopexy, 14% had laparoscopic gastropexy, and 7% had spleen repositioning and regeneration. Complications were noted in 60% of the cases resulting in postsplenopexy splenic ischemia. Early diagnosis and surgery are the best guarantee for spleen preservation. Even if the choice of one technique, splenopexy or gastropexy, can be argued, gastropexy has the advantage of avoiding splenic manipulation and restoring proper physiologic anatomy. When there is no history of abdominal surgery, laparoscopy surgery seems the best procedure.

  7. Multicenter Comparison of Seven 25OH Vitamin D Automated Immunoassays

    PubMed Central

    Lippi, Giuseppe; Salvagno, Gian Luca; Fortunato, Antonio; Dipalo, Mariella; Aloe, Rosalia; Da Rin, Giorgio; Giavarina, Davide

    2015-01-01

    Summary Background The measurement of 25OH vitamin D continues to grow in clinical laboratories. The aim of this multi-center study was to compare the results of seven automated commercial immunoassays with a reference HPLC technique. Methods One hundred and twenty consecutive outpatient serum samples were centrifuged, divided in aliquots, frozen and shipped to the participating laboratories. 25OH Vitamin D was measured with a reference HPLC system and with seven automated commercial immunoassays (Roche Cobas E601, Beckman Coulter Unicel DXI 800, Ortho Vitros ES, DiaSorin Liaison, Siemens Advia Centaur, Abbott Architect i System and IDS iSYS). Results Compared to the reference method, the regression coefficients ranged from 0.923 to 0.961 (all p<0.001). The slope of Deming fit ranged from 0.95 to 1.06, whereas the intercept was comprised between −15.2 and 9.2 nmol/L. The bias from the reference HPLC technique varied from −14.5 to 8.7 nmol/L. The minimum performance goal for bias was slightly exceeded by only one immunoassay. The agreement between HPLC and the different immunoassays at 50 nmol/L 25OH Vitamin D varied between 0.61 and 0.85 (all p<0.001). The percentage of samples below this cut-off was significantly different with only one immunoassay. Conclusions The excellent correlation with the reference HPLC technique attests that all seven automated immunoassays may be reliably used for routine assessment of 25OH-D in clinical laboratories. The significant bias among the different methods seems mostly attributable to the lack of standardization and calls for additional efforts for improving harmonization of 25OH-D immunoassays. PMID:28356846

  8. A fully nonparametric estimator of the marginal survival function based on case-control clustered age-at-onset data.

    PubMed

    Gorfine, Malka; Bordo, Nadia; Hsu, Li

    2017-01-01

    SummaryConsider a popular case-control family study where individuals with a disease under study (case probands) and individuals who do not have the disease (control probands) are randomly sampled from a well-defined population. Possibly right-censored age at onset and disease status are observed for both probands and their relatives. For example, case probands are men diagnosed with prostate cancer, control probands are men free of prostate cancer, and the prostate cancer history of the fathers of the probands is also collected. Inherited genetic susceptibility, shared environment, and common behavior lead to correlation among the outcomes within a family. In this article, a novel nonparametric estimator of the marginal survival function is provided. The estimator is defined in the presence of intra-cluster dependence, and is based on consistent smoothed kernel estimators of conditional survival functions. By simulation, it is shown that the proposed estimator performs very well in terms of bias. The utility of the estimator is illustrated by the analysis of case-control family data of early onset prostate cancer. To our knowledge, this is the first article that provides a fully nonparametric marginal survival estimator based on case-control clustered age-at-onset data.

  9. 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

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

    PubMed

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

    2013-03-01

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

  11. 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

  12. ROADTRIPS: case-control association testing with partially or completely unknown population and pedigree structure.

    PubMed

    Thornton, Timothy; McPeek, Mary Sara

    2010-02-12

    Genome-wide association studies are routinely conducted to identify genetic variants that influence complex disorders. It is well known that failure to properly account for population or pedigree structure can lead to spurious association as well as reduced power. We propose a method, ROADTRIPS, for case-control association testing in samples with partially or completely unknown population and pedigree structure. ROADTRIPS uses a covariance matrix estimated from genome-screen data to correct for unknown population and pedigree structure while maintaining high power by taking advantage of known pedigree information when it is available. ROADTRIPS can incorporate data on arbitrary combinations of related and unrelated individuals and is computationally feasible for the analysis of genetic studies with millions of markers. In simulations with related individuals and population structure, including admixture, we demonstrate that ROADTRIPS provides a substantial improvement over existing methods in terms of power and type 1 error. The ROADTRIPS method can be used across a variety of study designs, ranging from studies that have a combination of unrelated individuals and small pedigrees to studies of isolated founder populations with partially known or completely unknown pedigrees. We apply the method to analyze two data sets: a study of rheumatoid arthritis in small UK pedigrees, from Genetic Analysis Workshop 15, and data from the Collaborative Study of the Genetics of Alcoholism on alcohol dependence in a sample of moderate-size pedigrees of European descent, from Genetic Analysis Workshop 14. We detect genome-wide significant association, after Bonferroni correction, in both studies.

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

    PubMed

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

    2000-01-01

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

  14. 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

  15. 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

  16. 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

  17. A Multicenter Reference Intervals Study for Specific Proteins in China

    PubMed Central

    Qin, Xuzhen; Tang, Guodong; Qiu, Ling; Li, Peng Chang; Xia, Liangyu; Chen, Ming; Tao, Zhihua; Li, Shijun; Liu, Min; Wang, Liang; Gao, Shang; Yu, Songlin; Cheng, Xinqi; Han, Jianhua; Hou, Li’an; Kawano, Reo; Ichihara, Kiyoshi

    2015-01-01

    Abstract A multicenter study conducted in healthy population of 6 cities from the 4 corners and central China for 7 serum-specific proteins to identify the sources of variation and establish the reference intervals on 2 automation platforms. A total of 3148 subjects aged 19 to 64 years old were enrolled in this study to ensure at least 120 participants in each 10-year age group and each city. The majority of samples were transported to central laboratory and measured on both Beckman AU5800 and Immage 800 analytical systems. Three-level nested ANOVA, multiple regression analysis, and the scatter plot were used to explore the variations from sex, age, region, BMI, cigarette smoking, and so on. The latent abnormal value exclusion (LAVE) method was applied at the time of computing RIs as a method for secondary exclusion. Regionality was not observed in any of the immunoassay in China. Variations for sex were significant for IgM among the immune analytes. For CRP and hsCRP results with turbidimetry method (Beckman Coulter AU5800) were lower than the nephelometry method (Beckman Immage). The LAVE method did not affect the RIs computed for the majority of analytes except C4, CRP, and hsCRP. In the scatter plot at the age of 45 years old C3, C4, and IgM reached an inflection point, accordingly RIs were separated by the age group. With the lack of regional differences and the well-standardized status of test results, the RIs of C3, IgG, IgA, IgM derived from this nationwide study can be used for the entire Chinese population. C4, CRP, and hsCRP were affected by different platforms and gender was a significant source of variation for IgM, so they had separated RIs. PMID:26656356

  18. 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

  19. HLA-DR EXPRESSION AS A BIOMARKER OF INFLAMMATION FOR MULTICENTER CLINICAL TRIALS OF OCULAR SURFACE DISEASE

    PubMed Central

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

    2014-01-01

    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

  20. A molecular case-control study of the Merkel cell polyomavirus in colon cancer.

    PubMed

    Campello, Cesare; Comar, Manola; D'Agaro, Pierlanfranco; Minicozzi, Anna; Rodella, Luca; Poli, Albino

    2011-04-01

    To explore the putative role of the Merkel cell polyomavirus in human colon cancer, a prospective molecular case-control study was undertaken in patients and their relatives enrolled during a screening program. Fresh tissue samples from 64 cases of colon cancer (mean age 69.9 ± 11.0 years; 40 males) and fresh biopsies from 80 relatives (mean age 53.7 ± 8.6 years; 43 male; 55 son/daughter, 23 brother/sister, 2 parents) were analyzed by PCR and sequencing. Pre-cancerous lesions, namely adenomas and polyps, were detected in 15 (18.8%) and 9 (11.2%) of the controls, respectively. In addition, 144 blood samples were examined. Merkel cell polyomavirus DNA was detected in 6.3% of cases and 8.8% of controls. This difference was not statistically significant in the logistic regression analysis, after adjustment for age. Whereas blood samples from both cases and controls tested negative, the DNA Merkel cell polyomavirus was identified in 12.5% of adenoma/polyp tissues. No statistically significant difference was found when prevalence rates of Merkel cell polyomavirus in normal, pre-cancerous and cancer tissues were compared. Sequence analysis of the viral LT3 and VP1 regions showed high homology (>99%) with those of strains circulating worldwide, especially with genotypes detected in France. The findings of this survey are consistent with the hypothesis that the Merkel cell polyomavirus, in addition to other human polyomaviruses, can be recovered frequently from the gastrointestinal tract, because it is transmitted throughout the fecal-oral route. Moreover, the study does not indicate a role for Merkel cell polyomavirus in the genesis of colon cancer.

  1. Prospective Multicenter International Surveillance of Azole Resistance in Aspergillus fumigatus

    PubMed Central

    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.

    2015-01-01

    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

  2. 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.

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

    PubMed Central

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

    2010-01-01

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

  4. Urine metabolomics in neonates with late-onset sepsis in a case-control study

    PubMed Central

    Sarafidis, Kosmas; Chatziioannou, Anastasia Chrysovalantou; Thomaidou, Agathi; Gika, Helen; Mikros, Emmanouel; Benaki, Dimitra; Diamanti, Elisavet; Agakidis, Charalampos; Raikos, Nikolaos; Drossou, Vasiliki; Theodoridis, Georgios

    2017-01-01

    Although late-onset sepsis (LOS) is a major cause of neonatal morbidity and mortality, biomarkers evaluated in LOS lack high diagnostic accuracy. In this prospective, case-control, pilot study, we aimed to determine the metabolic profile of neonates with LOS. Urine samples were collected at the day of initial LOS evaluation, the 3rd and 10th day, thereafter, from 16 septic neonates (9 confirmed and 7 possible LOS cases) and 16 non-septic ones (controls) at respective time points. Urine metabolic profiles were assessed using non-targeted nuclear magnetic resonance spectroscopy and targeted liquid chromatography-tandem mass spectrometry analysis. Multivariate statistical models with data from either analytical approach showed clear separation between the metabolic profiles of septic neonates (both possible and confirmed) and the controls. Metabolic changes appeared to be related to disease progression. Overall, neonates with confirmed or possible LOS exhibited comparable metabolic profiles indicating similar metabolic alternations upon the onset of clinical manifestations. This methodology therefore enabled the discrimination of neonates with LOS from non-septic individuals, providing potential for further research toward the discovery of LOS-related biomarkers. PMID:28374757

  5. 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

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

    PubMed Central

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

    2016-01-01

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

  7. 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

  8. A class of multiplicity adjusted tests for spatial clustering based on case-control point data.

    PubMed

    Tango, Toshiro

    2007-03-01

    A class of tests with quadratic forms for detecting spatial clustering of health events based on case-control point data is proposed. It includes Cuzick and Edwards's test statistic (1990, Journal of the Royal Statistical Society, Series B 52, 73-104). Although they used the property of asymptotic normality of the test statistic, we show that such an approximation is generally poor for moderately large sample sizes. Instead, we suggest a central chi-square distribution as a better approximation to the asymptotic distribution of the test statistic. Furthermore, not only to estimate the optimal value of the unknown parameter on the scale of cluster but also to adjust for multiple testing due to repeating the procedure by changing the parameter value, we propose the minimum of the profile p-value of the test statistic for the parameter as an integrated test statistic. We also provide a statistic to estimate the areas or cases which make large contributions to significant clustering. The proposed methods are illustrated with a data set concerning the locations of cases of childhood leukemia and lymphoma and another on early medieval grave site locations consisting of affected and nonaffected grave sites.

  9. 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

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

    PubMed

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

    2012-09-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2005-01-01

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

  13. 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.

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

    PubMed Central

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

    1996-01-01

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

  15. A case-control study of the impact of improved sanitation on diarrhoea morbidity in Lesotho.

    PubMed Central

    Daniels, D. L.; Cousens, S. N.; Makoae, L. N.; Feachem, R. G.

    1990-01-01

    A health impact evaluation of the Rural Sanitation Pilot Project in Mohale's Hoek district, Lesotho, was conducted from October 1987 to September 1988. A clinic-based case-control design was used to investigate the impact of improved sanitation on diarrhoea morbidity in young children. The results indicate that under-5-year-olds from households with a latrine may experience 24% fewer episodes of diarrhoea than such children from households without a latrine (odds ratio = 0.76; 95% confidence interval, 0.58-1.01). The impact of latrines on diarrhoea was greater in those households that used more water, practised better personal hygiene, and where the mothers had a higher level of education or worked outside the home. In common with studies conducted in Malawi, Philippines, and Sri Lanka, little evidence was found that the relationship between latrine ownership and diarrhoea was confounded by socioeconomic status or environmental variables. For a sample of cases and controls, data on exposure status (presence or absence of a latrine) that were collected by interview at the clinics agreed closely with those obtained by observation during a home visit. PMID:2208559

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

    PubMed Central

    Stein, H S; Jones, I S

    1988-01-01

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

  17. 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.

  18. 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.

  19. A Case-controlled Investigation of Pain Experience and Sensory Function in Neuronal Ceroid Lipofuscinosis

    PubMed Central

    Barney, Chantel C.; Hoch, John; Byiers, Breanne; Dimian, Adele; Symons, Frank J.

    2014-01-01

    Objectives This case-control study explored pain experience and expression among individuals with Neuronal Ceroid Lipofuscinosis (NCL) through parental report, tactile-sensory testing, and infrared thermography (IRT). Methods Individuals with NCL (n=8; M age= 14.8 years) and their unaffected siblings (n=8;M age 23.5 years) were characterized in terms of pain response to a brief tactile sensory test (light touch, Von Frey monofilament). During sensory testing, behavioral expression was measured using the Battens Observational Pain Scale (BOPS) and infrared thermography (IRT) was used to quantify changes in skin/eye temperature. Results Individuals with NCL experienced pain frequently and from multiple sources that negatively impacted their lives. Individuals with NCL were reactive to the sensory testing as indexed by significant increased IRT temperature change (p<.001). Across combined sensory conditions, individuals with NCL were significantly more reactive (BOPS total score) to sensory testing compared to siblings (p< .05). Similarly, IRT difference scores between sensory conditions revealed a significant increase in temperature for individuals with NCL compared to siblings (p<.001). Discussion Ongoing reported pain was a problem for the individuals with NCL in this sample. Increased pain expression during the repeated Von Frey filament suggests that the pathophysiology of the ongoing pain may be centrally mediated. PMID:25569218

  20. [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.

  1. GATM polymorphism associated with the risk for statin-induced myopathy does not replicate in case-control analysis of 715 dyslipidemic individuals.

    PubMed

    Luzum, Jasmine A; Kitzmiller, Joseph P; Isackson, Paul J; Ma, Changxing; Medina, Marisa W; Dauki, Anees M; Mikulik, Eduard B; Ochs-Balcom, Heather M; Vladutiu, Georgirene D

    2015-04-07

    Statin-induced myopathy (SIM) is the most common reason for discontinuation of statin therapy. A polymorphism affecting the gene encoding glycine amidinotransferase (GATM rs9806699 G > A) was previously associated with reduced risk for SIM. Our objective was to replicate the GATM association in a large, multicenter SIM case-control study. Mild and severe SIM cases and age- and gender-matched controls were enrolled. Participants were genotyped, and associations were tested (n = 715) using chi-square and logistic regression with consideration for SIM severity and exclusion of subjects with potentially confounding comedications. The minor allele (A) frequencies of GATM rs9806699 in the controls (n = 106), mild SIM (n = 324), and severe SIM (n = 285) cases were 0.26, 0.28, and 0.29, respectively (p = 0.447). The unadjusted odds ratio for the A allele for any SIM (mild or severe) was 1.14 (0.82-1.61; p = 0.437), which remained nonsignificant in all models. Our results do not replicate the association between GATM rs9806699 and SIM.

  2. Multi-center harmonization of flow cytometers in the context of the European "PRECISESADS" project.

    PubMed

    Jamin, Christophe; Le Lann, Lucas; Alvarez-Errico, Damiana; Barbarroja, Nuria; Cantaert, Tineke; Ducreux, Julie; Dufour, Aleksandra Maria; Gerl, Velia; Kniesch, Katja; Neves, Esmeralda; Trombetta, Elena; Alarcón-Riquelme, Marta; Marañon, Concepción; Pers, Jacques-Olivier

    2016-11-01

    The innovative medicine initiative project called PRECISESADS will study 2.500 individuals affected by systemic autoimmune diseases (SADs) and controls. Among extensive OMICS approaches, multi-parameter flow cytometry analyses will be performed in eleven different centers. Therefore, the integration of all data in common bioinformatical and biostatistical investigations requires a fine mirroring of all instruments. We describe here the procedure elaborated to achieve this prerequisite. One flow cytometer chosen as reference instrument fixed the mean fluorescence intensities (MFIs) of 8 different fluorochrome-conjugated antibodies (Abs) using VersaComp Ab capture beads. The ten other centers adjusted their own PMT voltages to reach the same MFIs. Subsequently, all centers acquired Rainbow 8-peak beads data on a daily basis to follow the stability of their instrument overtime. One blood sample has been dispatched and concomitantly stained in all centers. Comparison of leukocytes frequencies and cell surface marker MFIs demonstrated the close sensitivity of all flow cytometers, allowing a multicenter analysis. The effective multi-center harmonization enables the constitution of a workable wide flow cytometry database for the identification of specific molecular signatures in individuals with SADs.

  3. 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.

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

    PubMed

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

    1999-01-01

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

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

    PubMed Central

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

    2017-01-01

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

  6. 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

  7. Stable Atlas-based Mapped Prior (STAMP) machine-learning segmentation for multicenter large-scale MRI data.

    PubMed

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

    2014-09-01

    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

  8. Amniocentesis and chorionic villus sampling.

    PubMed Central

    Shulman, L P; Elias, S

    1993-01-01

    Amniocentesis and chorionic villus sampling have been shown through prospective, multicenter trials to be safe and effective methods of prenatal diagnosis; accordingly, a knowledge of these tests is important for those physicians who care for women during their childbearing years. We review the indications, techniques, safety, accuracy, and efficacy of amniocentesis and chorionic villus sampling and compare the advantages and disadvantages of each diagnostic test. This review should enable physicians to provide appropriate counseling and information to women at increased risk for fetal abnormalities detectable by either of these procedures. Images PMID:8236967

  9. Spanish Multicenter Normative Studies (NEURONORMA Project): norms for Boston naming test and token test.

    PubMed

    Peña-Casanova, Jordi; Quiñones-Ubeda, Sonia; Gramunt-Fombuena, Nina; Aguilar, Miquel; Casas, Laura; Molinuevo, José Luis; Robles, Alfredo; Rodríguez, Dolores; Barquero, María Sagrario; Antúnez, Carmen; Martínez-Parra, Carlos; Frank-García, Anna; Fernández, Manuel; Molano, Ana; Alfonso, Verónica; Sol, Josep M; Blesa, Rafael

    2009-06-01

    As part of the Spanish Multicenter Normative Studies (NEURONORMA project), we provide age- and education-adjusted norms for the Boston naming test and Token test. The sample consists of 340 and 348 participants, respectively, who are cognitively normal, community-dwelling, and ranging in age from 50 to 94 years. Tables are provided to convert raw scores to age-adjusted scaled scores. These were further converted into education-adjusted scaled scores by applying regression-based adjustments. Age and education affected the score of the both tests, but sex was found to be unrelated to naming and verbal comprehension efficiency. Our norms should provide clinically useful data for evaluating elderly Spaniards. The normative data presented here were obtained from the same study sample as all the other NEURONORMA norms and the same statistical procedures for data analyses were applied. These co-normed data allow clinicians to compare scores from one test with all tests.

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

    PubMed

    Yaseen, Hakam

    2009-03-01

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

  11. Plasma Protein Biomarkers for Depression and Schizophrenia by Multi Analyte Profiling of Case-Control Collections

    PubMed Central

    Domenici, Enrico; Willé, David R.; Tozzi, Federica; Prokopenko, Inga; Miller, Sam; McKeown, Astrid; Brittain, Claire; Rujescu, Dan; Giegling, Ina; Turck, Christoph W.; Holsboer, Florian; Bullmore, Edward T.; Middleton, Lefkos; Merlo-Pich, Emilio; Alexander, Robert C.; Muglia, Pierandrea

    2010-01-01

    Despite significant research efforts aimed at understanding the neurobiological underpinnings of psychiatric disorders, the diagnosis and the evaluation of treatment of these disorders are still based solely on relatively subjective assessment of symptoms. Therefore, biological markers which could improve the current classification of psychiatry disorders, and in perspective stratify patients on a biological basis into more homogeneous clinically distinct subgroups, are highly needed. In order to identify novel candidate biological markers for major depression and schizophrenia, we have applied a focused proteomic approach using plasma samples from a large case-control collection. Patients were diagnosed according to DSM criteria using structured interviews and a number of additional clinical variables and demographic information were assessed. Plasma samples from 245 depressed patients, 229 schizophrenic patients and 254 controls were submitted to multi analyte profiling allowing the evaluation of up to 79 proteins, including a series of cytokines, chemokines and neurotrophins previously suggested to be involved in the pathophysiology of depression and schizophrenia. Univariate data analysis showed more significant p-values than would be expected by chance and highlighted several proteins belonging to pathways or mechanisms previously suspected to be involved in the pathophysiology of major depression or schizophrenia, such as insulin and MMP-9 for depression, and BDNF, EGF and a number of chemokines for schizophrenia. Multivariate analysis was carried out to improve the differentiation of cases from controls and identify the most informative panel of markers. The results illustrate the potential of plasma biomarker profiling for psychiatric disorders, when conducted in large collections. The study highlighted a set of analytes as candidate biomarker signatures for depression and schizophrenia, warranting further investigation in independent collections. PMID

  12. 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.

  13. 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

  14. 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

  15. The Glioma International Case-Control Study: A Report From the Genetic Epidemiology of Glioma International Consortium

    PubMed Central

    Amirian, E. Susan; Armstrong, Georgina N.; Zhou, Renke; Lau, Ching C.; Claus, Elizabeth B.; Barnholtz-Sloan, Jill S.; Il'yasova, Dora; Schildkraut, Joellen; Ali-Osman, Francis; Sadetzki, Siegal; Johansen, Christoffer; Houlston, Richard S.; Jenkins, Robert B.; Lachance, Daniel; Olson, Sara H.; Bernstein, Jonine L.; Merrell, Ryan T.; Wrensch, Margaret R.; Davis, Faith G.; Lai, Rose; Shete, Sanjay; Amos, Christopher I.; Scheurer, Michael E.; Aldape, Kenneth; Alafuzoff, Irina; Brännström, Thomas; Broholm, Helle; Collins, Peter; Giannini, Caterina; Rosenblum, Marc; Tihan, Tarik; Melin, Beatrice S.; Bondy, Melissa L.

    2016-01-01

    Decades of research have established only a few etiological factors for glioma, which is a rare and highly fatal brain cancer. Common methodological challenges among glioma studies include small sample sizes, heterogeneity of tumor subtypes, and retrospective exposure assessment. Here, we briefly describe the Glioma International Case-Control (GICC) Study (recruitment, 2010–2013), a study being conducted by the Genetic Epidemiology of Glioma International Consortium that integrates data from multiple data collection sites, uses a common protocol and questionnaire, and includes biospecimen collection. To our knowledge, the GICC Study is the largest glioma study to date that includes collection of blood samples, which will allow for genetic analysis and interrogation of gene-environment interactions. PMID:26656478

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

    PubMed

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

    2007-01-01

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

  17. An updated review of case-control studies of lung cancer and indoor radon-Is indoor radon the risk factor for lung cancer?

    PubMed

    Sheen, Seungsoo; Lee, Keu Sung; Chung, Wou Young; Nam, Saeil; Kang, Dae Ryong

    2016-01-01

    Lung cancer is a leading cause of cancer-related death in the world. Smoking is definitely the most important risk factor for lung cancer. Radon ((222)Rn) is a natural gas produced from radium ((226)Ra) in the decay series of uranium ((238)U). Radon exposure is the second most common cause of lung cancer and the first risk factor for lung cancer in never-smokers. Case-control studies have provided epidemiological evidence of the causative relationship between indoor radon exposure and lung cancer. Twenty-four case-control study papers were found by our search strategy from the PubMed database. Among them, seven studies showed that indoor radon has a statistically significant association with lung cancer. The studies performed in radon-prone areas showed a more positive association between radon and lung cancer. Reviewed papers had inconsistent results on the dose-response relationship between indoor radon and lung cancer risk. Further refined case-control studies will be required to evaluate the relationship between radon and lung cancer. Sufficient study sample size, proper interview methods, valid and precise indoor radon measurement, wide range of indoor radon, and appropriate control of confounders such as smoking status should be considered in further case-control studies.

  18. Prospective Multicenter Study of Children With Bronchiolitis Requiring Mechanical Ventilation

    PubMed Central

    Piedra, Pedro A.; Stevenson, Michelle D.; Sullivan, Ashley F.; Forgey, Tate F.; Clark, Sunday; Espinola, Janice A.; Camargo, Carlos A.

    2012-01-01

    OBJECTIVE: To identify factors associated with continuous positive airway pressure (CPAP) and/or intubation for children with bronchiolitis. METHODS: We performed a 16-center, prospective cohort study of hospitalized children aged <2 years with bronchiolitis. For 3 consecutive years from November 1 until March 31, beginning in 2007, researchers collected clinical data and a nasopharyngeal aspirate from study participants. We oversampled children from the ICU. Samples of nasopharyngeal aspirate were tested by polymerase chain reaction for 18 pathogens. RESULTS: There were 161 children who required CPAP and/or intubation. The median age of the overall cohort was 4 months; 59% were male; 61% white, 24% black, and 36% Hispanic. In the multivariable model predicting CPAP/intubation, the significant factors were: age <2 months (odds ratio [OR] 4.3; 95% confidence interval [CI] 1.7–11.5), maternal smoking during pregnancy (OR 1.4; 95% CI 1.1–1.9), birth weight <5 pounds (OR 1.7; 95% CI 1.0–2.6), breathing difficulty began <1 day before admission (OR 1.6; 95% CI 1.2–2.1), presence of apnea (OR 4.8; 95% CI 2.5–8.5), inadequate oral intake (OR 2.5; 95% CI 1.3–4.3), severe retractions (OR 11.1; 95% CI 2.4–33.0), and room air oxygen saturation <85% (OR 3.3; 95% CI 2.0–4.8). The optimism-corrected c-statistic for the final model was 0.80. CONCLUSIONS: In this multicenter study of children hospitalized with bronchiolitis, we identified several demographic, historical, and clinical factors that predicted the use of CPAP and/or intubation, including children born to mothers who smoked during pregnancy. We also identified a novel subgroup of children who required mechanical respiratory support <1 day after respiratory symptoms began. PMID:22869823

  19. 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

  20. Multicenter patient records research: security policies and tools.

    PubMed

    Behlen, F M; Johnson, S B

    1999-01-01

    The expanding health information infrastructure offers the promise of new medical knowledge drawn from patient records. Such promise will never be fulfilled, however, unless researchers first address policy issues regarding the rights and interests of both the patients and the institutions who hold their records. In this article, the authors analyze the interests of patients and institutions in light of public policy and institutional needs. They conclude that the multicenter study, with Institutional Review Board approval of each study at each site, protects the interests of both. "Anonymity" is no panacea, since patient records are so rich in information that they can never be truly anonymous. Researchers must earn and respect the trust of the public, as responsible stewards of facts about patients' lives. The authors find that computer security tools are needed to administer multicenter patient records studies and describe simple approaches that can be implemented using commercial database products.

  1. 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.

  2. Bacteraemic urinary tract infections may mimic respiratory infections: a nested case-control study.

    PubMed

    Denis, E; Martis, N; Guillouet-de Salvador, F; Demonchy, E; Degand, N; Carles, K; Roger, P-M

    2016-10-01

    Daily practice suggests that respiratory signs may be observed in bacteraemic urinary infections (BUI). Our objective was to search for an association between the presence of respiratory symptoms and the bacteraemic nature of urinary tract infections (UTI). A nested case-control study was carried out based on our computerised dashboard from January 2011 to June 2015. Cases were defined as patients with a BUI due to Enterobacteriaceae species, identified in blood and urine cultures. Controls had fever and a positive urinary sample but sterile blood cultures (NBUI) and a final diagnosis of urinary infection. Patients from the BUI group were 1:1 matched to the NBUI group according to four parameters: age, gender, cardiovascular and pulmonary comorbid conditions. Subjects with cognitive impairment limiting clinical accuracy and those with healthcare-associated infections were excluded. We compared systematically recorded respiratory and urinary symptoms between groups: signs on auscultation, dyspnoea, chest pain, cough and sputum, dysuria with burning, pollakiuria, flank or costovertebral angle tenderness and ischuria. One hundred BUI were compared to 100 NBUI, both groups exhibiting a similar rate for all considered comorbid conditions. In the BUI group, 58 % showed at least one respiratory sign vs. 20 % in the NBUI group, p < 0.001, while urinary signs were less frequent: 54 % vs. 71 %, p = 0.013. In the multivariate analysis, BUI was associated with the presence of abnormal pulmonary auscultation [adjusted odds ratio (AOR), 5.91; p < 0.001] and a trend towards less urinary symptoms (AOR, 1.58; p = 0.058). Patients with BUI presented with significantly more respiratory signs, which overshadowed urinary symptoms, compared to those with non-bacteraemic UTI. Such observations impact clinical decision-making.

  3. Ultrasound evaluation of intrinsic plantar muscles and fascia in hallux valgus: A case-control study.

    PubMed

    Lobo, César Calvo; Marín, Alejandro Garrido; Sanz, David Rodríguez; López, Daniel López; López, Patricia Palomo; Morales, Carlos Romero; Corbalán, Irene Sanz

    2016-11-01

    A cross-sectional area (CSA) and thickness reduction of the abductor hallucis (AbH) is shown in subjects with hallux valgus (HV). To date, other soft-tissue structures have not been researched in relation with HV. The aim of this study was to compare the CSA and thickness of the intrinsic plantar muscles and fascia (PF) between feet with and without HV. Therefore, a cross-sectional and case-control study was performed using B-mode with an iU22 Philips ultrasound system and a 5 to 17-MHz transducer. The CSA and thickness were measured for the AbH, flexor digitorum brevis (FDB) and flexor hallucis brevis (FHB), and also the thickness for the anterior, middle, and posterior PF portions. A convenience sample of 40 feet, 20 with HV and 20 without HV, was recruited from a clinical and research center. A multivariate regression analysis using linear regression was performed to evaluate the ultrasound imaging measurements (α = 0.05). Consequently, statistically significant differences were observed between the groups (P < 0.05) for the AbH and FHB thickness, and CSA reduction, and also the plantar fascia thickness increase in favor of the HV group. On the contrary, the FDB thickness and CSA did not show statistically significant differences (P ≥ 0.05). In conclusion, the CSA and thickness of the AbH and FHB intrinsic plantar muscles are reduced, whereas the thickness of the anterior, middle, and posterior PF portions are increased, in subjects with HV compared with those without HV.

  4. Predictors of acute diarrhoea among hospitalized children in Gaza Governorates: a case-control study.

    PubMed

    Alnawajha, Samer Khader; Bakry, Ghadeer Abdo; Aljeesh, Yousef Ibrahim

    2015-03-01

    This study aims to determine the predictors of acute diarrhoea among hospitalized children in the Gaza Governorates. The case-control design included 140 children (70 cases and 70 controls) in a stratified cluster sample from Naser Medical Complex and Alnasser Pediatric Hospital. An interview questionnaire was used, and face and content validations were performed. Multiple logistic regression was used for the multivariate analysis of risk factors of diarrhoea in children aged less than five years. Results showed a significant association between diarrhoea and family income, residence, complementary feeding, and age of weaning (p<0.05). Children living in villages had lower odds of having diarrhoea by 53.2% than children living in cities. Children of families with incomes between US$ 485 and 620 had lower odds of having diarrhoea by 80.8% than children of families with incomes less than US$ 485. Moreover, children who did not receive complementary feeding had lower odds of having diarrhoea by 59.0%. We found that, for one month increase in weaning age, the odds of diarrhoea decreased by 1.06 times (adjusted OR=1.05, 95% CI 1.0180-1.100). The study concludes that urban residence, lower family income, complementary feeding, and lower age of weaning are risk factors of diarrhoea among children aged less than five years in the Gaza Strip. The results of the study suggest that children of low-income families and those who were not naturally breastfed may warrant more attention for prevention and/or treatment of diarrhoea.

  5. 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

  6. Case-control study of breast cancer in south east England: nutritional factors

    PubMed Central

    Cade, J.; Thomas, E.; Vail, A.

    1998-01-01

    OBJECTIVES: To explore dietary risk factors, in particular fat intake, for breast cancer, using an approach to reduce recall bias of subjects and so provide a more reliable estimate of dietary intake than previous similar studies. DESIGN: A case-control study of women aged 50-65 years attending the breast assessment clinics of the breast screening programme in Southampton and Portsmouth, southern England. Data were analysed for all women requiring further clinical procedures; all women recalled to have an early rescreen; and a random sample of women found to be normal and referred for a routine rescreening appointment (standard recall). MEASUREMENTS: An interview obtained information on various lifestyle characteristics including smoking and alcohol intake, weight, waist, and hip measurements were also taken at the clinic. Women were given a detailed questionnaire on food intake to complete at home and return by post. RESULTS: 1577 women were included in the study: 220 with breast cancer (cases); 179 with benign breast disease; 353 early rescreen and 825 given a standard recall appointment. There were few differences in nutritional intake between the four groups. Logistic regression analyses were carried out comparing the dietary intake of cases with that of each control group adjusting for important demographic and reproductive factors. Results for the case and standard recall comparison are presented. The only non-calorific nutrient to reach significance was iron, which was negatively associated with risk (p = 0.03). For fat intake, the odds decreased with increasing polyunsaturated fat (p = 0.15), showed no trend with monounsaturated fat (p = 0.37) and increased (p = 0.10) with increasing saturated fat. No pattern was clear for the other calorie providing nutrients. CONCLUSIONS: In line with recent cohort studies, this study has shown no evidence to support the hypothesis that dietary fat is an important contributor to breast cancer rates. Biases should have

  7. 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

  8. 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

  9. Risk Factor of Preterm Labor in the West of Iran: A Case-Control Study

    PubMed Central

    DERAKHSHI, Bahareh; ESMAILNASAB, Nader; GHADERI, Ebrahim; HEMMATPOUR, Siroos

    2014-01-01

    Abstract Background Prematurity is the most common cause of neonatal death. Risk factors of premature birth can be related with ethnicity and genetic. There is no comprehensive high sample size study in Kurdish ethnicity to determine risk factors related to prematurity. This study evaluated risk factors of preterm labor in Kurdish ethnicity. Methods This case-control study was conducted in 200 preterm infants (case group) and 400 term infants (control group), in Besat Hospital, Sanandaj, Iran, in the year 2012. Data was analyzed using SPSS software and analysis was performed by Chi-square, Mann-Whitney and logistic regression tests. Results In univariate analysis, mother’s own prematurity, history of previous preterm labor, prematurity in the first-degree family members, history of dead children, premature rupture of membranes, multiple pregnancies, overt diabetes, chronic hypertension, preeclampsia and eclampsia, infertility and cervical incompetence had significant relation-ship with preterm labor. However, multivariate analysis results showed that abnormal amniotic fluid, premature rupture of membranes, double and multiple pregnancies, chronic hypertension, family history of premature birth, mothers age over 35 years, and cervical incompetence (P<0.05) had significant relationship with the premature birth. Conclusion Screening of newborns at risk of preterm labor could be achieved by these risk factors: family history of prematurity, mother’s own history of prematurity and previous preterm labor, history of previous neonatal death, decreased amniotic fluid, multiple pregnancies, overt diabetes, hypertension, preeclampsia, infertility and cervical incompetence, however some of these factors are not the direct cause of prematurity. Our study suggests genetic’ s role in preterm labor. PMID:26005661

  10. Antipsychotic Medications and Risk of Acute Coronary Syndrome in Schizophrenia: A Nested Case-Control Study

    PubMed Central

    Liu, Hsing-Cheng; Yang, Shu-Yu; Liao, Ya-Tang; Chen, Chiao-Chicy; Kuo, Chian-Jue

    2016-01-01

    Background This study assessed the risk of developing acute coronary syndrome requiring hospitalization in association with the use of certain antipsychotic medications in schizophrenia patients. Methods A nationwide cohort of 31,177 inpatients with schizophrenia between the ages of 18 and 65 years whose records were enrolled in the National Health Insurance Research Database in Taiwan from 2000 to 2008 and were studied after encrypting the identifications. Cases (n = 147) were patients with subsequent acute coronary syndrome requiring hospitalization after their first psychiatric admission. Based on a nested case-control design, each case was matched with 20 controls for age, sex and the year of first psychiatric admission using risk-set sampling. The effects of antipsychotic agents on the development of acute coronary syndrome were assessed using multiple conditional logistic regression and sensitivity analyses to confirm any association. Results We found that current use of aripiprazole (adjusted risk ratio [RR] = 3.68, 95% CI: 1.27–10.64, p<0.05) and chlorpromazine (adjusted RR = 2.96, 95% CI: 1.40–6.24, p<0.001) were associated with a dose-dependent increase in the risk of developing acute coronary syndrome. Although haloperidol was associated with an increased risk (adjusted RR = 2.03, 95% CI: 1.20–3.44, p<0.01), there was no clear dose-dependent relationship. These three antipsychotic agents were also associated with an increased risk in the first 30 days of use, and the risk decreased as the duration of therapy increased. Sensitivity analyses using propensity score-adjusted modeling showed that the results were similar to those of multiple regression analysis. Conclusions Patients with schizophrenia who received aripiprazole, chlorpromazine, or haloperidol could have a potentially elevated risk of developing acute coronary syndrome, particularly at the start of therapy. PMID:27657540

  11. 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

  12. Hyperemesis gravidarum and maternal cancer risk, a Scandinavian nested case-control study.

    PubMed

    Vandraas, Kathrine F; Grjibovski, Andrej M; Støer, Nathalie C; Troisi, Rebecca; Stephansson, Olof; Ording, Anne Gulbech; Vangen, Siri; Grotmol, Tom; Vikanes, Åse V

    2015-09-01

    Reproductive factors have been shown to influence cancer risk. Several pathological conditions during pregnancy have also been associated with subsequent altered cancer risk in the mother. Hyperemesis gravidarum (hyperemesis) is an early pregnancy condition characterized by severe nausea and vomiting resulting in weight loss and metabolic disturbances. Studies have reported associations between hyperemesis and cancer, but results are inconsistent. In this nested case-control study we linked the population-based medical birth registries and cancer registries in Norway, Sweden and Denmark in order to examine overall cancer risk and risk of specific cancer types in women with a history of hyperemesis, using conditional logistic regression. In total, 168,501 cases of cancer in addition to up to 10 cancer-free controls per case were randomly sampled, matched on year of birth and birth registry (n = 1,721,626). Hyperemesis was defined through the International Classification of Diseases. Analyses were adjusted for potential confounders. Hyperemesis was inversely associated with overall cancer risk with adjusted relative risk (aRR) of 0.93 (95% CI: 0.88-0.99), with cancer in the lungs (aRR: 0.60, 95% CI: 0.44-0.81), cervix (aRR: 0.66, 95% CI: 0.49-0.91) and rectum (aRR: 0.48, 95% CI: 0.29-0.78). Thyroid cancer was positively associated with hyperemesis (aRR 1.45, 95% CI: 1.06-1.99) and risk increased with more than one hyperemetic pregnancy (aRR 1.80, 95% CI: 1.23-2.63). Hormonal factors, in particular human chorionic gonadotropin, are likely to be involved in mediating these effects. This study is the first to systematically address these associations and provides valuable knowledge on potential long-term consequences of hyperemesis.

  13. Gender Specific Association of RAS Gene Polymorphism with Essential Hypertension: A Case-Control Study

    PubMed Central

    Dhanachandra Singh, Kh.; Jajodia, Ajay; Kaur, Harpreet; Kukreti, Ritushree; Karthikeyan, Muthusamy

    2014-01-01

    Renin-angiotensin system (RAS) polymorphisms have been studied as candidate risk factors for hypertension with inconsistent results, possibly due to heterogeneity among various genetic and environmental factors. A case-control association study was conducted to investigate a possible involvement of polymorphisms of three RAS genes: AGT M235T (rs699), ACE I/D (rs4340) and G2350A (rs4343), and AGTR1 A1166C (rs5186) in essential hypertensive patients. A total of 211 cases and 211 controls were recruited for this study. Genotyping was performed using PCR-RFLP method. The genotype and allele distribution of the M235T variant differed significantly in hypertensives and normotensives (OR-CI = 2.62 (1.24–5.76), P = 0.006; OR-CI = 0.699 (0.518–0.943), P = 0.018), respectively. When the samples were segregated based on sex, the 235TT genotype and T allele were predominant in the female patients (OR-CI = 5.68 (1.60-25.10), P = 0.002; OR-CI = 0.522 (0.330–0.826), P = 0.005) as compare to the male patients (OR-CI = 1.54 (1.24–5.76), P = 0.34; OR-CI = 0.874 (0.330–0.826), P = 0.506), respectively. For ACE DD variant, we found overrepresentation of “I”-allele (homozygous II and heterozygous ID) in unaffected males which suggest its protective role in studied population (OR-CI = 0.401 (0.224–0.718); P = 0.0009). The M235T variant of the AGT is significantly associated with female hypertensives and ACE DD variant could be a risk allele for essential hypertension in south India. PMID:24860821

  14. Case-control study of colon cancer and drinking water trihalomethanes in Wisconsin.

    PubMed

    Young, T B; Wolf, D A; Kanarek, M S

    1987-06-01

    A case-control study was conducted to test the hypothesis that chronic ingestion of trihalomethanes (THMs), occurring as chlorination byproducts in drinking water, carries a risk of colon cancer. Lifetime residential and water source histories and information on water-drinking habits, diet, sociodemographics, medical and occupation histories, lifestyle and other factors were obtained by questionnaire from a statewide sample of newly-diagnosed colon cancer cases (N = 347), controls with cancer of other sites (N = 639) and general population controls (N = 611). Since no data on past THM levels exists, it was necessary to devise a scheme to generate THM estimates for all Wisconsin water sources. For this, a statistical model based on quantitative THM measures and routinely-recorded data taken at 81 municipal water facilities was used in conjunction with individual residential histories to estimate lifetime and period-specific THM exposure for each case and control. Logistic regression was used to estimate odds ratios adjusted for age, sex and urban living, for colon cancer and THM exposure. The study results indicate that THM in Wisconsin drinking water does not pose a significant colon cancer risk. Odds ratios for exposure to the middle and highest category of lifetime cumulative THM were 1.05 (95% Cl = 0.66-1.68) and 0.93(95%Cl = 0.55-1.57) respectively, relative to the cancer control group, and 1.10 (95%Cl = 0.68-1.78) and 0.73 (95% Cl = 0.44-1.21) respectively, relative to the general population controls.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Subfertility and Risk of Testicular Cancer in the EPSAM Case-Control Study

    PubMed Central

    Zugna, Daniela; Fiano, Valentina; Robles Rodriguez, Nena; Maule, Milena; Gillio-Tos, Anna; Ciuffreda, Libero; Lista, Patrizia; Segnan, Nereo; Merletti, Franco; Richiardi, Lorenzo

    2016-01-01

    Background/objectives It has been suggested that subfertility and testicular cancer share genetic and environmental risk factors. We studied both subfertility and the strongest known testicular cancer susceptibility gene, the c-KIT ligand (KITLG), whose pathway is involved in spermatogenesis. Methods The EPSAM case-control study is comprised of testicular cancer patients from the Province of Turin, Italy, diagnosed between 1997 and 2008. The present analysis included 245 cases and 436 controls from EPSAM, who were aged 20 years or older at diagnosis/recruitment. The EPSAM questionnaire collected information on factors such as number of children, age at first attempt to conceive, duration of attempt to conceive, use of assisted reproduction techniques, physician-assigned diagnosis of infertility, number of siblings, and self-reported cryptorchidism. Genotyping of the KITLG single nucleotide polymorphism (SNP) rs995030 was performed on the saliva samples of 202 cases and 329 controls. Results Testicular cancer was associated with the number of children fathered 5 years before diagnosis (odds ratio (OR) per additional child: 0.78, 95% confidence interval (CI): 0.58–1.04) and sibship size (OR per additional sibling: 0.76, 95% CI: 0.66–0.88). When considering the reproductive history until 1 year before diagnosis, attempting to conceive for at least 12 months or fathering a child using assisted reproduction techniques was not associated with the risk of testicular cancer, nor was age at first attempt to conceive or physician-assigned diagnosis of infertility. The SNP rs995030 was strongly associated with risk of testicular cancer (per allele OR: 1.83; 95%CI: 1.26–2.64), but it did not modify the association between number of children and the risk of testicular cancer. Conclusion This study supports the repeatedly reported inverse association between number of children and risk of testicular cancer, but it does not find evidence of an association for other

  16. Metabolic disorders and the risk of nasopharyngeal carcinoma: a case-control study in Italy.

    PubMed

    Zucchetto, Antonella; Taborelli, Martina; Bosetti, Cristina; Montella, Maurizio; La Vecchia, Carlo; Franchin, Gianni; Libra, Massimo; Serraino, Diego; Polesel, Jerry

    2016-07-29

    The aim of this study is to evaluate the association between metabolic disorders and the risk of nasopharyngeal carcinoma, considering different histological subtypes. Between 1992 and 2008, we carried out a multicentre case-control study in Italy. One-hundred and ninety-seven White patients with histologically confirmed nasopharyngeal carcinoma were enrolled as cases. The control group included 592 cancer-free patients, frequency matched by study centre, area of residence, sex, age and period of interview. Odds ratios (OR) and corresponding 95% confidence intervals (CI), for nasopharyngeal carcinoma according to obesity and self-reported history of other metabolic disorders, were calculated through logistic regression models adjusted for matching variables and tobacco smoking and drinking habits. Obesity (OR=1.44; 95% CI: 0.88-2.36), diabetes mellitus (OR=0.91; 95% CI: 0.42-1.98), hypertension (OR=0.79; 95% CI: 0.48-1.32), hypercholesterolaemia (OR=1.41; 95% CI: 0.84-2.35) and metabolic syndrome (i.e. at least three among the four previously cited metabolic disorders; OR=1.11; 95% CI: 0.86-1.43) were not significantly associated with the overall risk of nasopharyngeal carcinoma. However, the associations observed for diabetes mellitus, hypercholesterolaemia and metabolic syndrome were stronger among differentiated nasopharyngeal carcinomas than among undifferentiated ones. In particular, 21.7% of differentiated nasopharyngeal carcinoma cases and 7.8% of controls reported a history of metabolic syndrome (OR=3.37; 95% CI: 1.05-10.81). The results of the study indicated no overall association between metabolic disorders and nasopharyngeal carcinoma. Nonetheless, although the small sample size calls for caution in interpretation, metabolic disorders could increase the risk of differentiated nasopharyngeal carcinoma. This finding further supports a different aetiology of the two histological subtypes.

  17. 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.

  18. Understanding patient-initiated frequent attendance in primary care: a case-control study.

    PubMed Central

    Báez, K; Aiarzaguena, J M; Grandes, G; Pedrero, E; Aranguren, J; Retolaza, A

    1998-01-01

    BACKGROUND: Frequent attendance, which accounts for a high proportion of the general practitioner's (GP's) workload, is still poorly understood. AIM: To assess the association and impact of exposure to chronic physical illness, mental disorders, life stress, and sociodemographic factors on the frequent attendance of primary health care medical services. METHOD: Nine general practices in Bizkaia, Spain, participated in a case-control study. Cases were patients who exceeded the 90th percentile in the distribution of the number of visits that they made on their own initiative from January 1993 to March 1994. Controls were those for whom a single, patient-initiated consultation was registered. A total of 102 cases and 100 controls were selected by stratified sampling proportional to the size of each practice. We estimated odds ratios and population attributable fractions for frequent attendance in relation to being exposed to the study variables, adjusted by demographic characteristics by means of logistic regression analysis. RESULTS: Medium-high life stress (adjusted odds ratio (AOR) = 4.5, 95% confidence interval (CI) = 1.7-12.8), chronic physical illness (AOR = 3.1; 95% CI = 1.4-6.9), mental disorder (AOR = 2.5; 95% CI = 1.3-5.1), and age were associated with patient-initiated frequent attendance. The adjusted population attributable fraction for chronic physical illness was 41%, 30.9% for mental disorder, and 15.2% for life stress. CONCLUSION: There is evidence that patient-initiated frequent attendance is related to genuine physical and psychosocial needs; therefore, recognition requires a bio-psychosocial approach on the part of GP. PMID:10198500

  19. Environmental risk factors contributing to traffic accidents in children: a case-control study.

    PubMed

    Jamshidi, Ensiyeh; Moradi, Ali; Majdzadeh, Reza

    2016-06-09

    The aim of this study is to identify environmental risk factors related to road accidents in children of Tehran. This case-control study was performed in 2013. The cases were injured pedestrians aged 5-15 who were admitted to major hospitals supervised by Tehran University of Medical Sciences. The sample size for the cases was 273 and for the control group was 546. For the completeness of the clusters, 7 extra persons in case (total = 280) and 14 persons (total = 560) in control group were included. The interference of confounding variables assessed through forward conditional logistic regression. Result shows occurrence of traffic accidents was significantly associate with the width of the alleys or (<5 m: OR = 8.4, 95% CI: 3.3-21.5; 5-8 m: OR = 4.7, 95% CI: 1.8-12.2), distance from home to school((<100 m: OR = 1.7, 95% CI: 1.0-2.8), existence of parking lot (OR = 1.5, 95% CI: 1.0-2.3), traffic congestion (OR = 4.1, 95% CI: 2.6-6.4), traffic speed (OR = 2.1, 95% CI: 1.3-3.2) and existence of pedestrian bridges(OR = 4.2, 95% CI: 2.6-6.8). In the light of the important role of environmental factors in the occurrence of child traffic accidents, alleviating structural risk factors in addition to education and enforcement need more systematic efforts and planning by policymakers and urban planners to attain pedestrian safety goals.

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

    PubMed Central

    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.

    2015-01-01

    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

  1. The pediatric heart network: meeting the challenges to multicenter studies in pediatric heart disease

    PubMed Central

    Burns, Kristin M.; Pemberton, Victoria L.; Pearson, Gail D.

    2017-01-01

    Purpose of review Because of the relatively small numbers of pediatric patients with congenital heart disease cared for in any individual center, there is a significant need for multicenter clinical studies to validate new medical or surgical therapies. The Pediatric Heart Network (PHN), with 15 years of experience in multicenter clinical research, has tackled numerous challenges when conducting multicenter studies. Recent findings This review describes the challenges encountered and the strategies employed to conduct high-quality, collaborative research in pediatric cardiovascular disease. Summary Sharing lessons learned from the PHN can provide guidance to investigators interested in conducting pediatric multicenter studies. PMID:26196261

  2. Spanish Multicenter Normative Studies (NEURONORMA Project): norms for verbal fluency tests.

    PubMed

    Peña-Casanova, Jordi; Quiñones-Ubeda, Sonia; Gramunt-Fombuena, Nina; Quintana-Aparicio, María; Aguilar, Miquel; Badenes, Dolors; Cerulla, Noemí; Molinuevo, José Luis; Ruiz, Eva; Robles, Alfredo; Barquero, Maria Sagrario; Antúnez, Carmen; Martínez-Parra, Carlos; Frank-García, Anna; Fernández, Manuel; Alfonso, Verónica; Sol, Josep M; Blesa, Rafael

    2009-06-01

    Lexical fluency tests are frequently used in clinical practice to assess language and executive function. As part of the Spanish multicenter normative studies (NEURONORMA project), we provide age- and education-adjusted norms for three semantic fluency tasks (animals, fruit and vegetables, and kitchen tools), three formal lexical tasks (words beginning with P, M, and R), and three excluded letter fluency tasks (excluded A, E, and S). The sample consists of 346 participants who are cognitively normal, community dwelling, and ranging in age from 50 to 94 years. Tables are provided to convert raw scores to age-adjusted scaled scores. These were further converted into education-adjusted scaled scores by applying regression-based adjustments. The current norms should provide clinically useful data for evaluating elderly Spanish people. These data may also be of considerable use for comparisons with other international normative studies. Finally, these norms should help improve the interpretation of verbal fluency tasks and allow for greater diagnostic accuracy.

  3. Correlation between nutritional biomarkers and breast cancer: a case-control study.

    PubMed

    Zaroukian, S; Pineault, R; Gandini, S; Lacroix, A; Ghadirian, P

    2005-06-01

    A case-control study to explore associations between retinoids, tocopherols, total and beta-carotenes and breast cancer was conducted by analysing concentrations of these biomarkers in adipose tissue, cheek cells and plasma. A total of 414 French-Canadians in Montreal with new diagnoses of breast cancer were age-matched to 429 population-based controls. Subjects were interviewed using a questionnaire, and biological samples from 287 cases and 112 controls were collected within 3 months of the diagnosis. Mean beta carotene concentrations in cheek cells were significantly lower among controls. Odds ratios (ORs) from logistic regression analysis were used to compare higher and lower tercile concentrations. Significant positive associations were observed in adipose tissue for retinoid [OR=2.11; 95% CI (1.09-4.08)] and beta carotene [OR=3.18; 95% CI (1.70-5.93)]; in cheek cells for beta carotene [OR=2.22; 95% CI (1.21-4.50)] and for total carotenes [OR=2.94; 95% CI (1.59-5.42)] and in plasma for beta carotene [OR=1.53; 95% CI (0.80-2.93)] and total carotenes [OR=1.04; 95% CI (0.53-2.05)]. Among the control groups, significant Pearson correlations were observed between cheek cells and adipose tissue for total carotenes (r=0.27; p=0.01) and cheek cells and plasma (r=0.22; p=0.04). In contrast to previous works, this study shows that high concentrations of retinoids and carotenes in adipose tissue and cheek cells are associated with increased risk of breast cancer. However, all these studies are limited by small sample size. Although our study tested a limited number of controls, important associations were observed. These results suggest that the effect of disease on biomarkers is fundamental to the interpretation of epidemiological data. We suggest either that the high levels of these biomarkers found in cancer patients in this study may be due to the disease process that affects the pharmacokinetics of the biomarker or that the disease causes a change in dietary habits

  4. Interventions to Increase Enrollment in a Large Multicenter Phase 3 Trial of Carotid Stenting versus Endarterectomy

    PubMed Central

    Longbottom, Mary E.; Roberts, Jamie N.; Tom, MeeLee; Hughes, Susan E.; Howard, Virginia J.; Sheffet, Alice J.; Meschia, James F.; Brott, Thomas G.

    2012-01-01

    Background Randomized clinical trials often encounter slow enrollment. Failing to meet sample size requirements has scientific, financial, and ethical implications. Aims We report interventions used to accelerate recruitment in a large multicenter clinical trial that was not meeting prespecified enrollment commitments. Methods The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) began randomization in December 2000. To accelerate enrollment, multiple recruitment tactics were initiated, which included expanding the number of sites; hiring a Recruitment Director (May 2003); broadening eligibility criteria (April 2005); branding with a study logo, website, and recruitment materials; increasing site visits by study leadership; sending emails to the site teams after every enrollment; distributing electronic newsletters; and implementing investigator and coordinator conferences. Results From December 2000 through May 2003, 14 sites became active (54 patients randomized); from June 2003 through April 2005, 44 sites were added (404 patients randomized); and from May 2005 through July 2008, 54 sites were added (2044 patients randomized). During these time intervals, the number of patients enrolled per site per year was 1.5, 3.6, and 5.6. For the single years 2004 to 2008, the mean monthly randomization rates per year were 19.7, 38.1, 56.4, 53.0, and 54.7 (annualized), respectively. Enrollment was highest after recruitment tactics were implemented: 677 patients in 2006, 636 in 2007, and 657 in 2008 (annualized). The prespecified sample size of 2502 patients, 47% asymptomatic, was accomplished July 2008. Conclusions Aggressive recruitment tactics and investment in a full-time Recruitment Director who can lead implementation may be effective in accelerating recruitment in multicenter trials. PMID:22631861

  5. Standardization of microparticle enumeration across different flow cytometry platforms: results of a multicenter collaborative workshop.

    PubMed

    Cointe, S; Judicone, C; Robert, S; Mooberry, M J; Poncelet, P; Wauben, M; Nieuwland, R; Key, N S; Dignat-George, F; Lacroix, R

    2017-01-01

    Essentials The clinical enumeration of microparticles (MPs) is hampered by a lack of standardization. A new strategy to standardize MP counts by flow cytometry was evaluated in a multicenter study. No difference was found between instruments using forward or side scatter as the trigger parameter. This study demonstrated that beads can be used as a standardization tool for MPs. Click to hear the ISTH Academy's webinar on microvesicles SUMMARY: Background Microparticles (MPs) are extracellular vesicles resulting from the budding of cellular membranes that have a high potential as emergent biomarkers; however, their clinical relevance is hampered by methodological enumeration concerns and a lack of standardization. Flow cytometry (FCM) remains the most commonly used technique with the best capability to determine the cellular origin of single MPs. However, instruments behave variably depending on which scatter parameter (forward (FSC) or side scatter (SSC)) provides the best resolution to discriminate submicron particles. To overcome this problem, a new approach, based on two sets of selected beads adapted to FSC or SSC-optimized instruments, was recently proposed to reproducibly enumerate platelet-derived MP counts among instruments with different optical systems. Objective The objective was to evaluate this strategy in an international workshop that included 44 laboratories accounting for 52 cytometers of 14 types. Methods/Results Using resolution capability and background noise level as criteria to qualify the instruments, the standardization strategy proved to be compatible with 85% (44/52) of instruments. All instruments correctly ranked the platelet MP (PMP) levels of two platelet-free plasma samples. The inter-laboratory variability of PMP counts was 37% and 28% for each sample. No difference was found between instruments using forward or side-scattered light as the relative sizing parameter. Conclusions Despite remaining limitations, this study is the first to

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

    PubMed

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

    2015-02-10

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

  7. Lysyl oxidase rs1800449 polymorphism and cancer risk among Asians: evidence from a meta-analysis and a case-control study of colorectal cancer.

    PubMed

    Gao, Xueren; Zhang, Shulong; Zhu, Zhansheng

    2015-02-01

    Growing evidence has indicated that lysyl oxidase (LOX) G473A polymorphism (rs1800449) is associated with cancer risk among Asians. However, results of single center and small sample study lack enough power. We first investigated the effect of LOX G473A polymorphism on cancer risk among Asians by a meta-analysis, and then further validated this association by a case-control study of colorectal cancer (CRC) with LOX G473A polymorphism in a Chinese population. STATA 12.0 software was used for the meta-analysis. The relationships were evaluated by calculating the pooled odds ratios (ORs) and their 95 % confidence intervals (CIs). In a case-control study comprising 577 CRC patients and 696 controls, LOX G473A polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Logistic regression was used to evaluate genetic associations with the occurrence of CRC. The results of our meta-analysis, including seven case-control studies with a total of 2,377 cancer patients and 2,499 controls, suggested that LOX G473A polymorphism might be associated with an increased risk of cancer among Asians. In addition, results of a case-control study indicated that individuals with the AA or AG genotype had a significantly increased susceptibility to CRC occurrence, compared with individuals who had GG genotype. Overall, this meta-analysis and case-control study of CRC observed convincing association of LOX G473A polymorphism with cancer risk in Asians; our study would contribute to complete elucidation of carcinogenesis.

  8. Risk factors in multiple sclerosis: a population-based case-control study in Sicily. Background and methods.

    PubMed

    Nicoletti, Alessandra; Messina, Silvia; Bruno, Elisa; Mostile, Giovanni; Quattrocchi, Graziella; Raciti, Loredana; Dibilio, Valeria; Cappellani, Roberto; D'Amico, Emanuele; Sciacca, Giorgia; Lo Fermo, Salvatore; Paradisi, Vincenza; Patti, Francesco; Zappia, Mario

    2016-12-01

    Incidence of multiple sclerosis (MS) has steeply increased over time during the last 30 years in the city of Catania. We carried out a population-based case-control study to evaluate the possible role of both environmental and genetic factors. From 1975 to 2004 in Catania, 367 MS patients diagnosed according to the Poser's criteria had the onset of disease. A sample of MS patients was randomly selected from this incident cohort. Three controls matched by age and sex were randomly selected from the rosters of 14 GPs. Controls were proportionally selected according to the distribution by municipality of the target population using a multistage sampling methods. All cases and controls underwent a face-to-face interview to record information concerning environmental factors and a blood sample was taken for serological and genetic analysis. 164 MS patients (64 % women; mean age of 46.4 ± 10.7) and 481 controls (69 % women; mean age of 47.7 ± 14.8) were enrolled in the study. The distribution of the whole population and the selected controls by municipalities was similar. A blood sample was taken from 150 MS cases and from 337 controls. At the end of the enrolment, we obtained a representative sample of the MS cases and population controls avoiding possible selection bias. Participation rate was very high also concerning the collection of biological specimens.

  9. 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

  10. Role of Parental Smoking in Severe Bronchiolitis: A Hospital Based Case-Control Study

    PubMed Central

    Hoque, Mujibul; Kamal, Mohammad Shah; Choudhury, Md. Moseh Uddin

    2017-01-01

    Objective. Bronchiolitis is one of the commonest causes of hospitalization of infants and young children in Bangladesh. About 21% of under 5 children attending different hospitals of Bangladesh have bronchiolitis. Fifty percent (50%) men and three percent (3%) women of Bangladesh are smokers. Parental smoking is an important risk factor for both susceptibility and severity of bronchiolitis. The aim of this study was to find out the role of parental smoking in severe bronchiolitis. Design. Case-control study. Place and Duration of Study. The study was conducted in the Department of Paediatrics, Sylhet MAG Osmani Medical College Hospital, Bangladesh, from July 2013 to December 2015. Patients and Methods. Sixty-four patients admitted into the ward with severe bronchiolitis were enrolled as cases and sixty-four suitably matched apparently healthy children attending EPI centre and outpatient department presenting with nonrespiratory illness were enrolled as controls. Sample size was calculated using Guilford and Frucher formula. The technique was systematic random sampling. Every second case satisfying the inclusion and exclusion criteria was enrolled in the study. Results. The mean age of the patients was 7.53 (SD ± 4.75) months. Forty (62.5%) patients were male and twenty four (37.5%) patients were female. Male-to-female ratio was 1.7 : 1. Most of the cases (60.95%) came from low socioeconomic background. More than half of the cases (53.13%) were not exclusively breastfed babies. Mean length of hospital stay was 6.41 (SD ± 2.82) days. Thirty eight (59%) cases and twenty six (34%) controls were exposed to parental smoking. Result was highly significant (p = 0.005). Odds ratio was 2.8 (95% CI from 1.36 to 5.72). Conclusion. Exposure to parental smoking causes a statistically significant (p = 0.005, odds ratio = 2.8) increase in the risk of developing severe bronchiolitis in the first year of life. PMID:28356915

  11. A gene-based information gain method for detecting gene-gene interactions in case-control studies.

    PubMed

    Li, Jin; Huang, Dongli; Guo, Maozu; Liu, Xiaoyan; Wang, Chunyu; Teng, Zhixia; Zhang, Ruijie; Jiang, Yongshuai; Lv, Hongchao; Wang, Limei

    2015-11-01

    Currently, most methods for detecting gene-gene interactions (GGIs) in genome-wide association studies are divided into SNP-based methods and gene-based methods. Generally, the gene-based methods can be more powerful than SNP-based methods. Some gene-based entropy methods can only capture the linear relationship between genes. We therefore proposed a nonparametric gene-based information gain method (GBIGM) that can capture both linear relationship and nonlinear correlation between genes. Through simulation with different odds ratio, sample size and prevalence rate, GBIGM was shown to be valid and more powerful than classic KCCU method and SNP-based entropy method. In the analysis of data from 17 genes on rheumatoid arthritis, GBIGM was more effective than the other two methods as it obtains fewer significant results, which was important for biological verification. Therefore, GBIGM is a suitable and powerful tool for detecting GGIs in case-control studies.

  12. Polymorphisms of the lipoprotein lipase gene as genetic markers for stroke in colombian population: a case control study

    PubMed Central

    Vargas Castellanos, Clara Inés; Silva Sieger, Federico Arturo

    2016-01-01

    Abstract Objective: To analyze if there is an association between the presence of polymorphisms in the LPL gene (rs320, rs285 and rs328) with development of acute ischemic stroke in Colombian population. Methods: In a case control design, 133 acute ischemic stroke patients (clinical diagnosis and x-ray CT) and 269 subjects without stroke as controls were studied. PCR -RFLP technique was used to detect rs320, rs285 and rs328 polymorphisms in the LPL gene. Results: In the present research was not found any association between any of the LPL gene polymorphism and acute ischemic stroke in the population studied; the allele and genotypic frequencies of the studied polymorphisms were similar in cases and controls and followed the Hardy-Weinberg equilibrium. The study was approved by the IRB and each subject signed the informed consent. Conclusion: LPL gene polymorphisms are not genetic markers for the development of stroke in the Colombian sample used. PMID:28293042

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

    PubMed Central

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

    1994-01-01

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

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

    ERIC Educational Resources Information Center

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

    2009-01-01

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

  15. 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…

  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. 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…

  18. 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...

  19. 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…

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

    PubMed

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

    2012-09-01

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

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

    ERIC Educational Resources Information Center

    Beautrais, Annette L.

    2002-01-01

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

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

    PubMed

    Lee, Wen-Chung

    2014-01-01

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

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

    PubMed

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

    2013-07-10

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

  4. 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…

  5. 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…

  6. 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

  7. Case-control analysis in highway safety: Accounting for sites with multiple crashes.

    PubMed

    Gross, Frank

    2013-12-01

    There is an increased interest in the use of epidemiological methods in highway safety analysis. The case-control and cohort methods are commonly used in the epidemiological field to identify risk factors and quantify the risk or odds of disease given certain characteristics and factors related to an individual. This same concept can be applied to highway safety where the entity of interest is a roadway segment or intersection (rather than a person) and the risk factors of interest are the operational and geometric characteristics of a given roadway. One criticism of the use of these methods in highway safety is that they have not accounted for the difference between sites with single and multiple crashes. In the medical field, a disease either occurs or it does not; multiple occurrences are generally not an issue. In the highway safety field, it is necessary to evaluate the safety of a given site while accounting for multiple crashes. Otherwise, the analysis may underestimate the safety effects of a given factor. This paper explores the use of the case-control method in highway safety and two variations to account for sites with multiple crashes. Specifically, the paper presents two alternative methods for defining cases in a case-control study and compares the results in a case study. The first alternative defines a separate case for each crash in a given study period, thereby increasing the weight of the associated roadway characteristics in the analysis. The second alternative defines entire crash categories as cases (sites with one crash, sites with two crashes, etc.) and analyzes each group separately in comparison to sites with no crashes. The results are also compared to a "typical" case-control application, where the cases are simply defined as any entity that experiences at least one crash and controls are those entities without a crash in a given period. In a "typical" case-control design, the attributes associated with single-crash segments are weighted

  8. Some epidemiologic, clinical, microbiologic, and organizational assumptions that influenced the design and performance of the Global Enteric Multicenter Study (GEMS).

    PubMed

    Farag, Tamer H; Nasrin, Dilruba; Wu, Yukun; Muhsen, Khitam; Blackwelder, William C; Sommerfelt, Halvor; Panchalingam, Sandra; Nataro, James P; Kotloff, Karen L; Levine, Myron M

    2012-12-01

    The overall aim of the Global Enteric Multicenter Study-1 (GEMS-1) is to identify the etiologic agents associated with moderate-to-severe diarrhea (MSD) among children <5 years of age, and thereby the attributable pathogen-specific population-based incidence of MSD, to guide investments in research and public health interventions against diarrheal disease. To accomplish this, 9 core assumptions were vetted through widespread consultation: (1) a limited number of etiologic agents may be responsible for most MSD; (2) a definition of MSD can be crafted that encompasses cases that might otherwise be fatal in the community without treatment; (3) MSD seen at sentinel centers is a proxy for fatal diarrheal disease in the community; (4) matched case/control is the appropriate epidemiologic design; (5) methods across the sites can be standardized and rigorous quality control maintained; (6) a single 60-day postenrollment visit to case and control households creates mini-cohorts, allowing comparisons; (7) broad support for GEMS-1 messages can be achieved by incorporating advice from public health spokespersons; (8) results will facilitate the setting of investment and intervention priorities; and (9) wide acceptance and dissemination of the GEMS-1 results can be achieved.

  9. Some Epidemiologic, Clinical, Microbiologic, and Organizational Assumptions That Influenced the Design and Performance of the Global Enteric Multicenter Study (GEMS)

    PubMed Central

    Farag, Tamer H.; Nasrin, Dilruba; Wu, Yukun; Muhsen, Khitam; Blackwelder, William C.; Sommerfelt, Halvor; Panchalingam, Sandra; Nataro, James P.; Kotloff, Karen L.; Levine, Myron M.

    2012-01-01

    The overall aim of the Global Enteric Multicenter Study–1 (GEMS-1) is to identify the etiologic agents associated with moderate-to-severe diarrhea (MSD) among children <5 years of age, and thereby the attributable pathogen-specific population-based incidence of MSD, to guide investments in research and public health interventions against diarrheal disease. To accomplish this, 9 core assumptions were vetted through widespread consultation: (1) a limited number of etiologic agents may be responsible for most MSD; (2) a definition of MSD can be crafted that encompasses cases that might otherwise be fatal in the community without treatment; (3) MSD seen at sentinel centers is a proxy for fatal diarrheal disease in the community; (4) matched case/control is the appropriate epidemiologic design; (5) methods across the sites can be standardized and rigorous quality control maintained; (6) a single 60-day postenrollment visit to case and control households creates mini-cohorts, allowing comparisons; (7) broad support for GEMS-1 messages can be achieved by incorporating advice from public health spokespersons; (8) results will facilitate the setting of investment and intervention priorities; and (9) wide acceptance and dissemination of the GEMS-1 results can be achieved. PMID:23169935

  10. 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.

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

    PubMed Central

    Caballería, Llorenç; Auladell, Ma Antonia; Torán, Pere; Pera, Guillem; Miranda, Dolores; Alumà, Alba; Casas, José Dario; Muñoz, Laura; Sanchez, Carmen; Tibau, Albert; Birules, Marti; Canut, Santiago; Bernad, Jesús; Aubà, Josep; Aizpurua, Miren Maite; Alcaraz, Enriqueta

    2008-01-01

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

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

    PubMed

    Xiao, Ying; Zhao, Yubin; Xie, Yanming

    2011-10-01

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

  13. Association between Dietary Inflammatory Index (DII) and risk of prediabetes: a case-control study.

    PubMed

    Vahid, Farhad; Shivappa, Nitin; Karamati, Mohsen; Naeini, Alireza Jafari; Hebert, James R; Davoodi, Sayed Hossein

    2017-04-01

    The possible relationship between diet-related inflammation and the risk of prediabetes requires further investigation, especially in non-Western populations. We examined the ability of the dietary inflammatory index (DII) to predict the risk of prediabetes in a case-control study conducted at specialized centers in Esfahan, Iran. A total of 214 incident cases of prediabetes were selected with the nonrandom sampling procedure, and the 200 controls randomly selected from the same clinics were frequency-matched on age (±5 years) and sex. DII scores were computed based on dietary intake assessed using a validated and reproducible 168-item food-frequency questionnaire. Linear and logistic regression models were used to estimate multivariable beta estimates and odds ratios (ORs). Subjects in tertile 3 versus tertile 1 (T3VS1) of DII had significantly higher fasting plasma glucose (DIIT3VS1: b = 4.49; 95% CI 1.89, 7.09), oral glucose tolerance (DIIT3VS1: b = 8.76; 95% CI 1.78, 15.73), HbA1c (DIIT3VS1: b = 0.30; 95% CI 0.17, 0.42), low-density lipoprotein (DIIT3VS1: b = 16.37; 95% CI 11.04, 21.69), triglyceride (DIIT3VS1: b = 21.01; 95% CI 8.61, 33.42) and body fat (DIIT3VS1: b = 2.41; 95% CI 0.56, 4.26) and lower high-density lipoprotein (DIIT3VS1: b = -3.39; 95% CI -5.94, -0.84) and lean body mass (DIIT3VS1: b = -3.11; 95% CI -4.83, -1.39). After multivariate adjustment, subjects in the most pro-inflammatory DII group had 19 times higher odds of developing prediabetes compared with subjects in tertile 1 (DIIT3VS1: OR = 18.88; 95% CI 7.02, 50.82). Similar results were observed when DII was used as a continuous variable, (DIIcontinuous: OR = 3.62; 95% CI 2.50, 5.22). Subjects who consumed a more pro-inflammatory diet were at increased risk of prediabetes compared with those who consumed a more anti-inflammatory diet.

  14. Vitamin D status and breast cancer in Saudi Arabian women: case-control study1234

    PubMed Central

    Yousef, Fatimah M; Jacobs, Elizabeth T; Kang, Paul T; Hakim, Iman A; Going, Scott; Yousef, Jehad M; Al-Raddadi, Rajaa M; Kumosani, Taha A; Thomson, Cynthia A

    2013-01-01

    Background: The role of vitamin D in breast cancer prevention is equivocal. Saudi Arabian women may be at greater risk of vitamin D deficiency because of a darker skin type and a greater likelihood of reduced ultraviolet B radiation exposure. Data regarding the vitamin D status of Saudi Arabian women and its relation to breast cancer risk are lacking. Objective: The purpose of this research was to evaluate the association between circulating concentrations of 25-hydroxyvitamin D [25(OH)D] and breast cancer risk in Saudi Arabian women. Design: A case-control study was conducted among 120 breast cancer cases and 120 controls. The study population was drawn from patients admitted to King Fahd Hospital in Jeddah, Saudi Arabia, from June to August 2009. Participants completed questionnaires on diet and medical history, and serum samples were collected from all women to measure circulating 25(OH)D concentrations. Results: The participants had a mean age of 47.8 y and a mean body mass index (BMI; in kg/m2) of 30.0. Breast cancer cases had significantly lower (mean ± SD) serum concentrations of 25(OH)D (9.4 ± 6.4 ng/mL) than did controls (15.4 ± 12.3 ng/mL; P = 0.001). In comparison with those in the highest category of vitamin D status for this population (≥20 ng/mL), the adjusted ORs (95% CIs) for invasive breast cancer were 6.1 (2.4, 15.1) for women with a serum 25(OH)D concentration <10 ng/mL and 4.0 (1.6, 10.4) for women with a serum concentration of ≥10 to <20 ng/mL (P-trend = 0.0001). Conclusion: An inverse association exists between serum 25(OH)D concentrations and breast cancer risk in Saudi Arabian women. This trial was registered at clinicaltrials.gov as NCT01817231. PMID:23697705

  15. Case-control study of occupational exposures and male breast cancer

    PubMed Central

    Cocco, P.; Figgs, L.; Dosemeci, M.; Hayes, R.; Linet, M. S.; Hsing, A. W.

    1998-01-01

    OBJECTIVE: To investigate whether risk of male breast cancer is associated with workplace exposures. METHODS: A case-control study of 178 cases of male breast cancer and 1041 controls was carried out with data from the United States national mortality follow-back survey, which collected questionnaire information from proxy respondents of a 1% sample of all 1986 United States deaths among subjects aged 25-74 years. Occupational exposure to electromagnetic fields, high temperatures, polycyclic aromatic hydrocarbons (PAHs), herbicides, other pesticides, and organic solvents was assessed by applying job- exposure matrices, based on the 1980 United States census occupation and industry codes, to the longest job held by study subjects as reported by the informants. A socioeconomic status index was created by combining information on annual family income, education, assets, and occupation to assess the association of socioeconomic status with male breast cancer. Relative risks were derived from logistic regression modelling, which included age, socioeconomic status, marital status, and body mass index, as well as occupational exposures. RESULTS: Risk for male breast cancer increased significantly with increasing socioeconomic status index (test for trend: p < 0.01), but the risks associated with individual socioeconomic status variables were smaller and the trends were not significant. A significant increase in risk of male breast cancer was associated with employment in blast furnaces, steel works, and rolling mills (odds ratio (OR) 3.4; 95% confidence interval (95% CI) 1.1 to 10.1, based on six cases), and motor vehicle manufacturing (OR 3.1; 95% CI 1.2 to 8.2, based on seven cases). However, exposures to electromagnetic fields, high temperature, PAHs, herbicides, other pesticides, and organic solvents were not associated with risk of male breast cancer. CONCLUSIONS: The role of workplace exposures in increasing risk of breast cancer among men employed in motor vehicle

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

    DTIC Science & Technology

    2010-05-01

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

  17. 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

  18. Determinants of first trimester attendance at antenatal care clinics in the Amazon region of Peru: A case-control study

    PubMed Central

    Moore, Nora; Blouin, Brittany; Razuri, Hugo; Casapia, Martin; Gyorkos, Theresa W.

    2017-01-01

    Objective To identify determinants which influence the timing of the first antenatal care (ANC) visit in pregnant women. Design Retrospective matched nested case-control study. Setting Two health centres, Belén and 6 de Octubre, in the Peruvian Amazon. Population All pregnant women who had attended ANC during the years 2010, 2011, and 2012. Methods All cases (819 women initiating ANC in their first trimester) were selected from ANC registries from 2010 to 2012. A random sample of controls (819 women initiating ANC in their second or third trimester) was matched 1:1 to cases on health centre and date of first ANC visit. Data were obtained from ANC registries. Conditional logistic regression analyses were performed. Main outcome measure Case-control status of each woman determined by the gestational age at first ANC visit. Results Cases had higher odds of: 1) being married or cohabiting (aOR = 1.69; 95% CI: 1.19, 2.41); 2) completing secondary school or attending post-secondary school (aOR = 1.45; 95% CI: 1.02, 2.06); 3) living in an urban environment (aOR = 1.79; 95% CI: 1.04, 3.10) and 4) having had a previous miscarriage (aOR = 1.56; 95% CI: 1.13, 2.15), compared to controls. No statistically significant difference in odds was found for parity (aOR = 1.08; 95% CI: 0.85, 1.36). Conclusions This study provides empirical evidence of determinants of first ANC attendance. These findings are crucial to the planning and timing of local interventions, like deworming, aimed at pregnant women so that they can access and benefit fully from all government-provided ANC services. PMID:28207749

  19. 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.

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

    PubMed Central

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

    2015-01-01

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

    PubMed Central

    Crombie, I K

    1981-01-01

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

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

    PubMed

    Rose, Sherri; van der Laan, Mark

    2014-03-15

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

  4. [Multicenter trial for sudden hearing loss therapy - planning and concept].

    PubMed

    Plontke, S K; Girndt, M; Meisner, C; Probst, R; Oerlecke, I; Richter, M; Steighardt, J; Dreier, G; Weber, A; Baumann, I; Plößl, S; Löhler, J; Laszig, R; Werner, J A; Rahne, T

    2016-04-01

    Systemic steroids are widely used worldwide as a standard of care for primary therapy of idiopathic sudden sensorineural hearing loss (ISSHL). The German ISSHL guideline recommends high-dose steroids for primary therapy of ISSHL, without evidence from randomized controlled trials (RCTs). The rationale for the treatment of ISSHL using high dose steroids is only based on retrospective cohort studies.This article describes the planning and initiation of a multicenter, national, randomized, controlled clinical trial entitled Efficacy and safety of high dose glucocorticosteroid treatment for idiopathic sudden sensorineural hearing loss - a three-armed, randomized, triple-blind, multicenter trial (HODOKORT). This clinical trial aims to compare standard dose with two types of high-dose steroids for primary systemic therapy with respect to their efficacy in improving hearing, and thus communication ability, in patients with idiopathic sudden sensorineural hearing loss.This study is funded by the "Clinical Trials with High Patient Relevance" research program in the health research framework of the German Federal Ministry of Education and Research. It is one of two studies by the German Study Center of Clinical Trials of the German Society of Otorhinolaryngology, Head and Neck Surgery (DSZ-HNO). Planning and initiation was done in cooperation with the DSZ-HNO, the Coordination Center of Clinical Trials of the Martin-Luther-University Halle-Wittenberg, and the Study Center of the University Hospital Freiburg.

  5. Primary Hepatic Lymphoma: A Retrospective, Multicenter Rare Cancer Network Study

    PubMed Central

    Ugurluer, Gamze; Miller, Robert C.; Li, Yexiong; Thariat, Juliette; Ghadjar, Pirus; Schick, Ulrike; Ozsahin, Mahmut

    2016-01-01

    Primary hepatic lymphoma (PHL) is a rare malignancy. We aimed to assess the clinical profile, outcome and prognostic factors in PHL through the Rare Cancer Network (RCN). A retrospective analysis of 41 patients was performed. Median age was 62 years (range, 23-86 years) with a male-to-female ratio of 1.9:1.0. Abdominal pain or discomfort was the most common presenting symptom. Regarding B-symptoms, 19.5% of patients had fever, 17.1% weight loss, and 9.8% night sweats. The most common radiological presentation was multiple lesions. Liver function tests were elevated in 56.1% of patients. The most common histopathological diagnosis was diffuse large B-cell lymphoma (65.9%). Most of the patients received Chop-like (cyclophosphamide, doxorubicin, vincristine, and prednisone) regimens; 4 patients received radiotherapy (dose range, 30.6-40.0 Gy). Median survival was 163 months, and 5- and 10-year overall survival rates were 77 and 59%, respectively. The 5- and 10-year disease-free and lymphoma-specific survival rates were 69, 56, 87 and 70%, respectively. Multivariate analysis revealed that fever, weight loss, and normal hemoglobin level were the independent factors influencing the outcome. In this retrospective multicenter RCN study, patients with PHL had a relatively better prognosis than that reported elsewhere. Multicenter prospective studies are still warranted to establish treatment guidelines, outcome, and prognostic factors. PMID:27746888

  6. MAIN ETHICAL BREACHES IN MULTICENTER CLINICAL TRIALS REGULATIONS OF TURKEY

    PubMed Central

    Ekmekci, P. Elif

    2017-01-01

    Turkey has been a growing market for multicenter clinical trials for the last ten years and is considered among the top ten countries in terms of potential study subject populations. The objective of increasing the share of Turkey in multicenter clinical trials is strongly supported. This ambitious goal of Turkey raises the need to have regulations in compliance with other leading countries conducting clinical trials. The latest published Turkish regulations on clinical trials are structured in compliance with the International Conference on Harmonization (ICH) Guidelines and in harmony with the regulations of other leading countries in clinical research, such as the US. There are still flaws in Turkish regulation with the risk of violating human subjects’ rights and issues with responsible conduct of research. The aim of this article is to compare Turkish clinical trials regulations with those of the US, to determine if there exists any incompatibility between the countries’ regulations and, if so, how to ameliorate these. The main flaws in Turkish clinical trials regulations are identified as follows: lack of definition of the term “human subject; absence of explicit referral to the unacceptability of Conflict of Interest (COI) and taking measures to avoid it; exiguity of emphasis on plurality of the IRB members; nonexistence of a clear expression that this is research; and clinical equipoise, regarding the treatment of the existing clinical problem and lack of integration with international accreditation systems for Institutional Review Boards.

  7. Research and operational applications in multi-center ensemble forecasting

    NASA Astrophysics Data System (ADS)

    Zhu, Y.; Toth, Z.

    2009-05-01

    The North American Ensemble Forecast System (NAEFS) was built up in 2004 by the Meteorological Service of Canada (MSC), the National Meteorological Service of Mexico (NMSM), and the US National Weather Service (NWS) as an operational multi-center ensemble forecast system. Currently it combines the 20-member MSC and NWS ensembles to form a joint ensemble of 40 members twice a day. The joint ensemble forecast, after bias correction and statistical downscaling, is used to generate a suite of products for CONUS, North America and for other regions of the globe. The THORPEX Interactive Grand Global Ensemble (TIGGE) project has been established a few years ago to collect operational global ensemble forecasts from world centers, and distribute to the scientific community, to encourage research leading to the acceleration of improvements in the skill and utility of high impact weather forecasts. TIGGE research is expected to advise the development of the operational NAEFS system and eventually the two projects are expected to converge into a single operational system, the Global Interactive Forecast System (GIFS). This presentation will review recent developments, the current status, and plans related to the TIGGE research and NAEFS operational multi-center ensemble projects.

  8. Computational method for general multicenter electronic structure calculations.

    PubMed

    Batcho, P F

    2000-06-01

    Here a three-dimensional fully numerical (i.e., chemical basis-set free) method [P. F. Batcho, Phys. Rev. A 57, 6 (1998)], is formulated and applied to the calculation of the electronic structure of general multicenter Hamiltonian systems. The numerical method is presented and applied to the solution of Schrödinger-type operators, where a given number of nuclei point singularities is present in the potential field. The numerical method combines the rapid "exponential" convergence rates of modern spectral methods with the multiresolution flexibility of finite element methods, and can be viewed as an extension of the spectral element method. The approximation of cusps in the wave function and the formulation of multicenter nuclei singularities are efficiently dealt with by the combination of a coordinate transformation and a piecewise variational spectral approximation. The complete system can be efficiently inverted by established iterative methods for elliptical partial differential equations; an application of the method is presented for atomic, diatomic, and triatomic systems, and comparisons are made to the literature when possible. In particular, local density approximations are studied within the context of Kohn-Sham density functional theory, and are presented for selected subsets of atomic and diatomic molecules as well as the ozone molecule.

  9. 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

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

    PubMed Central

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

    2012-01-01

    Background Case-control studies are a common and efficient means of studying rare diseases or illnesses with long latency periods. Matching of cases and controls is frequently employed to control the effects of known potential confounding variables. The analysis of matched data requires specific statistical methods. Methods The objective of this study was to determine the proportion of published, peer-reviewed matched case-control studies that used statistical methods appropriate for matched data. Using a comprehensive set of search criteria we identified 37 matched case-control studies for detailed analysis. Results Among these 37 articles, only 16 studies were analyzed with proper statistical techniques (43%). Studies that were properly analyzed were more likely to have included case patients with cancer and cardiovascular disease compared to those that did not use proper statistics (10/16 or 63%, versus 5/21 or 24%, P = 0.02). They were also more likely to have matched multiple controls for each case (14/16 or 88%, versus 13/21 or 62%, P = 0.08). In addition, studies with properly analyzed data were more likely to have been published in a journal with an impact factor listed in the top 100 according to the Journal Citation Reports index (12/16 or 69%, versus 1/21 or 5%, P ≤ 0.0001). Conclusion The findings of this study raise concern that the majority of matched case-control studies report results that are derived from improper statistical analyses. This may lead to errors in estimating the relationship between a disease and exposure, as well as the incorrect adaptation of emerging medical literature. PMID:22570570

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

    DTIC Science & Technology

    2009-05-01

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

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

    DTIC Science & Technology

    2011-05-01

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

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

    DTIC Science & Technology

    2010-05-01

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

  14. 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

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

    PubMed

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

    1988-10-01

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

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

    PubMed

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

    2012-12-01

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

  17. 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

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

    PubMed

    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; Fernandes Filho, J Americo M; 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

    2014-06-01

    Abstract 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 utilize an extensive structured telephone interview ascertaining environmental, lifestyle, dietary and psychological risk factors associated with OS. Detailed assessments were performed at baseline and at 3-6 month intervals during the ensuing 30 months. Our biorepository includes DNA, plasma, urine, and skin. Three hundred and fifty-five 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. Results showed that demographic and disease characteristics were similar between 477 eligible/non-enrolled and enrolled patients, the only difference being type of health insurance among enrolled patients. Sites were divided into three groups by the number of enrolled subjects. Comparing these three groups, the Columbia site had fewer 'definite ALS' diagnoses. This is the first prospective, interdisciplinary, in-depth, multicenter epidemiological investigation of OS related to ALS progression and has been accomplished by an aggressive recruitment process. The baseline demographic and disease features of the study sample are now fully characterized.

  19. 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

  20. Meat and fish consumption and risk of lung cancer: A case-control study in Galicia, Spain.

    PubMed

    Dosil-Díaz, O; Ruano-Ravina, A; Gestal-Otero, J J; Barros-Dios, J M

    2007-07-08

    Diet is one of the elements that may influence the development of lung cancer. To ascertain the relationship between meat and fish consumption and the appearance of this disease, a case-control study was conducted on a population in Galicia (NW Spain), with a sample of 295 cases and 322 controls. All cases had histologic confirmation, and controls were individuals who were attending the hospital to undergo trivial surgery. All subjects were over 35, and sampling was based on sex frequency. Frequent consumption of meat seemed to have a protective effect, with an OR of 0.24 (95% CI 0.11-0.50), an effect that was maintained for pork consumption (OR 0.35; 95% CI 0.18-0.67). In contrast, consumption of fish showed an association with lung cancer, with an OR of 1.67 (95% CI 0.99-2.81), an association that extended to both white (OR 1.61 95% CI 0.93-2.79) and blue fish (OR 2.03 95% CI 1.23-3.34). Consumption of meat seems to reduce the risk of lung cancer, whereas consumption of fish could exert an influence by increasing the risk of this disease.

  1. Beta Human Papillomavirus Infection Is Prevalent in Elephantiasis and Exhibits a Productive Phenotype: A Case-Control Study.

    PubMed

    Carlson, John Andrew; Rady, Peter; Kadam, Pooja; He, Qin; Simonette, Rebecca; Tyring, Stephen

    2017-02-03

    Elephantiasis is considered a cutaneous region of immune deficiency with cobblestone-like surface caused by a wart-like eruption. Verrucosis is a diffuse human papillomavirus (HPV) infection linked to immunodeficiency disorders. The objective of this study was to examine the prevalence of HPV infection in lymphedema and its pathogenic role in elephantiasis. A retrospective case-control study was performed examining lymphedematous skin and controls of peritumoral normal skin. HPV infection was evaluated at the DNA, protein, and histopathologic levels by polymerase chain reaction, immunohistochemistry, and light microscopy, respectively. Overall, 540 HPV DNAs were detected in 120 of 122 cutaneous samples (median 4 HPV DNAs per sample, range 0-9). Compared with controls, no differences existed in type or number of HPVs identified. Instead, a diverse spectrum of HPV-related histopathologies were evident, likely reflecting the multiplicity of HPV genotypes detected. Most notably, increasing histopathologic lymphedema stage significantly correlated with markers of productive HPV infection such as altered keratohyaline granules and HPV L1 capsid expression. Limitations of this study are the absence of normal skin controls not associated with neoplasia or subclinical lymphedema, and lack of assessment of HPV copy number per keratinocyte infected. In conclusion, productive HPV infection, not HPV type or numbers detected, distinguished lymphedematous skin from controls. These findings support the theory that lymphedema creates a region of depressed immunity that permits productive HPV infection, manifested clinically by diffuse papillomatosis, characteristic of elephantiasis.

  2. Family clustering of secondary chronic kidney disease with hypertension or diabetes mellitus. A case-control study.

    PubMed

    de Almeida, Fernando Antonio; Ciambelli, Giuliano Serafino; Bertoco, André Luz; Jurado, Marcelo Mai; Siqueira, Guilherme Vasconcelos; Bernardo, Eder Augusto; Pavan, Maria Valeria; Gianini, Reinaldo José

    2015-02-01

    In Brazil hypertension and type 2 diabetes mellitus are responsible for 60% of cases of end-stage renal disease in renal replacement therapy. In the United States studies have identified family clustering of chronic kidney disease, predominantly in African-Americans. A single Brazilian study observed family clustering among patients with chronic kidney disease when compared with hospitalized patients with normal renal function. This article aims to assess whether there is family clustering of chronic kidney disease in relatives of individuals in renal replacement therapy caused by hypertension and/or diabetes mellitus. A case-control study with 336 patients in renal replacement therapy with diabetes mellitus or hypertension for at least 5 years (cases) and a control matched sample group of individuals with hypertension or diabetes mellitus and normal renal function (n = 389). Individuals in renal replacement therapy (cases) had a ratio of 2.35 (95% CI 1.42-3.89, p < 0.001) versus the control group in having relatives with chronic renal disease, irrespective of race or causative illness. There is family clustering of chronic kidney disease in the sample studied, and this predisposition is irrespective of race and underlying disease (hypertension or diabetes mellitus).

  3. Effect of Latent Myofascial Trigger Points on Strength Measurements of the Upper Trapezius: A Case-Controlled Trial

    PubMed Central

    Anshul

    2011-01-01

    ABSTRACT Purpose: The purpose of this article was to determine whether strength is altered in the upper trapezius in the presence of latent myofascial trigger points (MTrP). Methods: This study was case controlled and used convenience sampling. The sample recruited was homogeneous with respect to age, sex, height, and body mass. Participants were assessed for the presence of latent MTrP in the upper trapezius and placed into two groups: an experimental group that had latent MTrP in the upper trapezius and a control group that did not. Eighteen women (mean age 21.4 y, SD 1.89; mean height 156.9 cm, SD 4.03; and mean body mass 51.7 kg, SD 5.84) made up the experimental group, and 19 women (mean age 20.3 y, SD 1.86; mean height 158.6 cm, SD 3.14; and mean body mass 53.2 kg, SD 5.17) made up the control group. We obtained strength measurements of the non-dominant arm using a handheld dynamometer and compared them between the two groups. Results: The difference in the strength measurements between the two groups was not statistically significant (p=0.59). Conclusions: The presence of latent MTrPs may not affect the strength of the upper trapezius. PMID:22942517

  4. 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

  5. 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

  6. 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

  7. Protocol and standard operating procedures for common use in a worldwide multicenter study on reference values.

    PubMed

    Ozarda, Yesim; Ichihara, Kiyoshi; Barth, Julian H; Klee, George

    2013-05-01

    The reference intervals (RIs) given in laboratory reports have an important role in aiding clinicians in interpreting test results in reference to values of healthy populations. In this report, we present a proposed protocol and standard operating procedures (SOPs) for common use in conducting multicenter RI studies on a national or international scale. The protocols and consensus on their contents were refined through discussions in recent C-RIDL meetings. The protocol describes in detail (1) the scheme and organization of the study, (2) the target population, inclusion/exclusion criteria, ethnicity, and sample size, (3) health status questionnaire, (4) target analytes, (5) blood collection, (6) sample processing and storage, (7) assays, (8) cross-check testing, (9) ethics, (10) data analyses, and (11) reporting of results. In addition, the protocol proposes the common measurement of a panel of sera when no standard materials exist for harmonization of test results. It also describes the requirements of the central laboratory, including the method of cross-check testing between the central laboratory of each country and local laboratories. This protocol and the SOPs remain largely exploratory and may require a reevaluation from the practical point of view after their implementation in the ongoing worldwide study. The paper is mainly intended to be a basis for discussion in the scientific community.

  8. Hydrogen multicenter bond in oxide and nitride semiconductors

    NASA Astrophysics Data System (ADS)

    Janotti, Anderson

    2009-03-01

    Hydrogen is a very reactive atom, occurring in virtually all organic and in many inorganic compounds. It can form a purely covalent bond, in which two hydrogen atoms share a pair of electrons in a two-electron two-center bond, as well as polar covalent bonds, such as in an H2O molecule. In solids, hydrogen is usually considered as an interstitial impurity. In elemental semiconductors, such as silicon, hydrogen forms a three-center bond when located at the bond center. In compound semiconductors, hydrogen bonds to the anionic species in p-type material, and to the cationic species in n-type. Thus far, hydrogen in solids has been found to form chemical bonds with one, two, or at most three other atoms. Higher coordination numbers are exceedingly rare and have been reported only for clusters. In this talk we will show that hydrogen is capable of forming multicenter bonds in solids, occupying substitutional sites. As examples, we discuss substitutional hydrogen impurities in oxides (ZnO, MgO, SnO2, TiO2) [1,2] and nitrides (InN, AlN, GaN) [3]. Based on first-principles calculations we show that hydrogen replaces oxygen (nitrogen) and forms genuine chemical bonds with multiple metal atoms, in truly multicoordinated configurations. These multicenter bonds are surprisingly strong despite the large hydrogen-metal distances when compared to typical values in hydrogen two-center bonds. Hydrogen in the multicenter bond configuration is a shallow donor in a number of materials. In conducting oxides, it provides a consistent explanation for the observed dependence of electrical conductivity on oxygen partial pressure, thus resolving a long-standing controversy on the role of point defects in unintentional n-type conductivity [1,2]. [4pt] [1] A. Janotti and C. G Van de Walle, Nature Materials 6, 44 (2007). [0pt] [2] A. K. Singh, A. Janotti, M. Scheffler, and C. G. Van de Walle, Phys. Rev. Lett. 101, 055502 (2008). [0pt] [3] A. Janotti and C. G. Van de Walle, Appl. Phys. Lett. 92

  9. Is Content of Medical Journals Related to Advertisements? Case-control Study

    PubMed Central

    Vlassov, Vasiliy V.

    2007-01-01

    Aim To assess the relatedness of journal content to paid advertisements published in the journal. Methods The case-control study was performed on a convenience sample of 7 journals subscribed by Central Medical Library in Moscow – 4 international (American Journal of Hypertension, British Journal of General Practice, The Lancet, and New England Journal of Medicine) and 3 Russian peer reviewed journals (Terapevticheskii Arkhiv, Khirurgiia, and Voeno-Meditsinskii Zhurnal). In each issue containing a paid advertisement, classifieds excluded, we searched for articles related to the advertised product and compared this issue with a control issue – the next or a later issue without this advertisement. Results In American Journal of Hypertension (33 issues from 2002-2004) 94 placements of advertisements were found, 7 of which were closely related to the article topic in the same issue (7/94) vs 2/66 in the control issue. The odds ratio (OR) and 95% confidence interval (CI) for advertisements to be accompanied by related articles was OR, 2.6; 95%CI, 0.5-13). In British Journal of General Practice (27 issues from 2003-2005) there were 7/63 advertisements related to the article topic vs 0/28 in the control issue (OR, 7.2; 95% CI, 1.3 to 44). In The Lancet (49 issues from 2004) there were 8/162 advertisements related to the article topic vs 8/104 in the control issue (OR, 0.6; 95% CI, 0.3-1.5). In New England Journal of Medicine (37 issues from 2004) there were 12/81 advertisements related to the article topic vs 8/75 in the control issue (OR, 1.5; 95% CI, 0.56-3.79). In Terapevticheskii Arkhiv (10 issues from 2004) there were 38/93 advertisements related to the article topic vs 1/83 in the control issue (OR, 56.66; 95% CI, 4.4-253). In Khirurgiia (25 issues from 2003-2005) there were 3/83 advertisements related to the article topic vs 0/70 in the control issue (OR, 2.7; 95% CI, 0.3-26). In Voeno-Meditsinskii Zhurnal (33 issues from 2003-2005) there were 17

  10. Factors predicting survival in ALS: a multicenter Italian study.

    PubMed

    Calvo, Andrea; Moglia, Cristina; Lunetta, Christian; Marinou, Kalliopi; Ticozzi, Nicola; Ferrante, Gianluca Drago; Scialo, Carlo; Sorarù, Gianni; Trojsi, Francesca; Conte, Amelia; Falzone, Yuri M; Tortelli, Rosanna; Russo, Massimo; Chiò, Adriano; Sansone, Valeria Ada; Mora, Gabriele; Silani, Vincenzo; Volanti, Paolo; Caponnetto, Claudia; Querin, Giorgia; Monsurrò, Maria Rosaria; Sabatelli, Mario; Riva, Nilo; Logroscino, Giancarlo; Messina, Sonia; Fini, Nicola; Mandrioli, Jessica

    2017-01-01

    The aim of this multicenter, retrospective study is to investigate the role of clinical characteristics and therapeutic intervention on ALS prognosis. The study included patients diagnosed from January 1, 2009 to December 31, 2013 in 13 Italian referral centers for ALS located in 10 Italian regions. Caring neurologists collected a detailed phenotypic profile and follow-up data until death into an electronic database. One center collected also data from a population-based registry for ALS. 2648 incident cases were collected. The median survival time from onset to death/tracheostomy was 44 months (SE 1.18, CI 42-46). According to univariate analysis, factors related to survival from onset to death/tracheostomy were: age at onset, diagnostic delay, site of onset, phenotype, degree of certainty at diagnosis according to revised El Escorial criteria (R-EEC), presence/absence of dementia, BMI at diagnosis, patients' provenance. In the multivariate analysis, age at onset, diagnostic delay, phenotypes but not site of onset, presence/absence of dementia, BMI, riluzole use, R-EEC criteria were independent prognostic factors of survival in ALS. We compared patients from an ALS Registry with patients from tertiary centers; the latter ones were younger, less frequently bulbar, but more frequently familial and definite at diagnosis. Our large, multicenter study demonstrated the role of some clinical and demographic factors on ALS survival, and showed some interesting differences between referral centers' patients and the general ALS population. These results can be helpful for clinical practice, in clinical trial design and to validate new tools to predict disease progression.

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

    PubMed Central

    Strachan, D.; Cook, D.

    1998-01-01

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

 PMID:9659358

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

    PubMed

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

    2017-04-01

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

  13. 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.

  14. 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

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

    PubMed

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

    1989-10-15

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

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

    PubMed

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

    2008-10-01

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

  17. 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.

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

    SciTech Connect

    Ames, R.G.

    1983-10-01

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

  19. 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.

  20. 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

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

    PubMed

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

    2009-08-01

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

  2. Socio-Demographic and Other Risk Factors of Pre Eclampsia at a Tertiary Care Hospital, Karnataka: Case Control Study

    PubMed Central

    Gandhi, Sangeetha; Rao, Vishwas

    2014-01-01

    Background: Pre-eclampsia is one of the leading causes of maternal and infant morbidity and mortality worldwide. The aetiopathogenesis of this condition involves combination of genetic predisposition and environmental factors. The aim of the study was to determine the socio demographic and other risk factors of pre-eclampsia. Materials and Methods: A case control study was conducted at a tertiary care hospital, Karnataka among 100 cases of pre-eclampsia and 200 controls without pre eclampsia. Non probability purposive sampling technique was adopted to select the study subjects. Data was collected by using a pre tested semi structured questionnaire which included information related to socio-demographic and other known risk factors of pre eclampsia. Primary data was collected by interviewing study subjects and secondary data of cases was obtained from case records. Data was analysed using SPSS. Results: Study subjects included 100 cases and 200 controls. Age of less than 20 y (OR=3.8), monthly income of less than Rs4000 (OR=6.8), age of menarche of less than 12 y (OR=13.1), family h/o pre eclampsia (OR=36.0), family h/o Diabetes (OR=44.9), family h/o hypertension (OR=16.7) and previous h/o PIH (OR=58.5) are found to be significant risk factors of pre eclampsia. Conclusion: The significant risk factors may be used for screening pre-eclampsia during registration of pregnancy. PMID:25386463

  3. 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.

  4. 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.

  5. 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

  6. Natural Killer Cell Assessment in Peripheral Circulation and Bronchoalveolar Lavage Fluid of Patients with Severe Sepsis: A Case Control Study.

    PubMed

    Souza-Fonseca-Guimaraes, Paulo; Guimaraes, Fernando; Natânia De Souza-Araujo, Caroline; Maria Boldrini Leite, Lidiane; Cristina Senegaglia, Alexandra; Nishiyama, Anita; Souza-Fonseca-Guimaraes, Fernando

    2017-03-12

    Sepsis is a complex systemic inflammatory syndrome, the most common cause of which is attributed to systemic underlying bacterial infection. The complete mechanisms of the dynamic pro- and anti-inflammatory processes underlying the pathophysiology of sepsis remain poorly understood. Natural killer (NK) cells play a crucial role in the pathophysiology of sepsis, leading to exaggerated inflammation due their rapid response and production of pro-inflammatory cytokines such as interferon gamma (IFN-γ). Several studies have already shown that NK cells undergo lymphopenia in the peripheral blood of patients with sepsis. However, our understanding of the mechanisms behind its cellular trafficking and its role in disease development is restricted to studies in animal models. In this study, we aimed to compare the human NK cell subset (CD56(bright or dim)) levels in the peripheral blood and bronchoalveolar lavage (BAL) fluid of sepsis patients. We conducted a case-control study with a sample size consisting of 10 control patients and 23 sepsis patients enrolled at the Hospital Cajuru (Curitiba/PR, Brazil) from 2013 to 2015. Although we were able to confirm previous observations of peripheral blood lymphopenia, no significant differences were detected in NK cell levels in the BAL fluid of these patients. Overall, these findings strengthened the evidence that peripheral blood lymphopenia is likely to be associated with cell death as a consequence of sepsis.

  7. 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.

  8. Association between Vitamin D Status and Coronary Heart Disease among Adults in Saudi Arabia: A Case-Control Study

    PubMed Central

    Aljefree, Najlaa M.; Lee, Patricia; Alsaqqaf, Jamal M.; Ahmed, Faruk

    2016-01-01

    Recent evidence has pointed out an association between vitamin D deficiency and coronary heart disease (CHD). Due to the growing epidemic of CHD and vitamin D deficiency in Saudi Arabia, exploring the role of vitamin D in the prevention of CHD is crucial. The aim of this study was to examine the association between vitamin D status and CHD in Saudi Arabian adults. This case-control study included 130 CHD cases and 195 age-sex matched controls. Study subjects were recruited from three hospitals in the western region of Saudi Arabia. Study participants were interviewed face-to-face to collect data on their socio-demographic characteristics and family history of CHD. Fasting blood samples were collected, and serum levels of vitamin D, glucose, and total cholesterol were measured. Body weight, height, and blood pressure measurements were also recorded. Severe vitamin D deficiency (25(OH)D < 10 ng/mL) was much more prevalent in CHD cases than in controls (46% and 3%, respectively). The results of multivariate logistic regression showed that vitamin D deficiency (25(OH)D < 20 ng/mL) was associated with CHD, with an odds ratio of 6.5 (95% CI: 2.7–15, p < 0.001). The current study revealed that vitamin D deficiency is independently associated with CHD, suggesting an important predictor of CHD among Saudi adults. PMID:27763496

  9. Outlining a Population “at Risk” of Parkinson's Disease: Evidence from a Case-Control Study

    PubMed Central

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

    2016-01-01

    The multifactorial pathogenesis of Parkinson's Disease (PD) requires a careful identification of populations “at risk” of developing the disease. In this case-control study we analyzed a large Italian population, in an attempt to outline general criteria to define a population “at risk” of PD. We enrolled 300 PD patients and 300 controls, gender and age matched, from the same urban geographical area. All subjects were interviewed on demographics, family history of PD, occupational and environmental toxicants exposure, smoking status, and alcohol consumption. A sample of 65 patients and 65 controls also underwent serum dosing of iron, copper, mercury, and manganese by means of Inductively Coupled-Plasma-Mass-Spectrometry (ICP-MS). Positive family history, toxicants exposure, non-current-smoker, and alcohol nonconsumer status occurred as significant risk factors in our population. The number of concurring risk factors overlapping in the same subject impressively increased the overall risk. No significant differences were measured in the metal serum levels. Our findings indicate that combination of three to four concurrent PD-risk factors defines a condition “at risk” of PD. A simple stratification, based on these questionnaires, might be of help in identifying subjects suitable for neuroprotective strategies. PMID:27651975

  10. Psychiatric disorders and cardiac anxiety in exercising and sedentary coronary artery disease patients: a case-control study

    PubMed Central

    Sardinha, A.; Araújo, C.G.S.; Nardi, A.E.

    2012-01-01

    Regular physical exercise has been shown to favorably influence mood and anxiety; however, there are few studies regarding psychiatric aspects of physically active patients with coronary artery disease (CAD). The objective of the present study was to compare the prevalence of psychiatric disorders and cardiac anxiety in sedentary and exercising CAD patients. A total sample of 119 CAD patients (74 men) were enrolled in a case-control study. The subjects were interviewed to identify psychiatric disorders and responded to the Cardiac Anxiety Questionnaire. In the exercise group (N = 60), there was a lower prevalence (45 vs 81%; P < 0.001) of at least one psychiatric diagnosis, as well as multiple comorbidities, when compared to the sedentary group (N = 59). Considering the Cardiac Anxiety Questionnaire, sedentary patients presented higher scores compared to exercisers (mean ± SEM = 55.8 ± 1.9 vs 37.3 ± 1.6; P < 0.001). In a regression model, to be attending a medically supervised exercise program presented a relevant potential for a 35% reduction in cardiac anxiety. CAD patients regularly attending an exercise program presented less current psychiatric diagnoses and multiple mental-related comorbidities and lower scores of cardiac anxiety. These salutary mental effects add to the already known health benefits of exercise for CAD patients. PMID:23011407

  11. Body Mass Index Is Associated With Mucosal Disease in Crohn’s: Results of a Case-Control Study

    PubMed Central

    Malik, Talha A.; Kaslow, Richard A.; Cofield, Stacey S.; Mannon, Peter J.

    2014-01-01

    Background Recent studies have suggested that increased body mass index (BMI) may have an adverse effect on treatment outcomes and natural history in Crohn’s disease (CD). We aimed to test the hypothesis that CD patients with higher BMI would be more likely than those with lower BMI to have persistent active mucosal disease. Methods We designed a case-control study. Sample population comprised CD patients with active disease at the beginning of observation. At the end of observation, cases had persistent active mucosal disease and controls had entered remission. With multivariable logistic regression models, we evaluated the effect of baseline BMI as a continuous variable and a categorical variable on persistent active mucosal disease. Results We analyzed data from 104 patients (36 cases and 68 controls). In a model containing BMI as a continuous variable, higher BMI was significantly associated with persistent active mucosal disease (odds ratio (OR) = 1.09 per unit increase; 95% confidence interval (CI), 1.02 - 1.17; P = 0.012). In a model containing BMI as a categorical variable, obese patients were 2.7 times more likely to have persistent active mucosal disease compared to non-obese patients (OR = 2.72; 95% CI, 1.00 - 7.35; P = 0.049). Conclusion Excessive weight measured both quantitatively as BMI and categorically as obesity in CD patients is associated with persistent active mucosal disease. PMID:27785280

  12. Natural Killer Cell Assessment in Peripheral Circulation and Bronchoalveolar Lavage Fluid of Patients with Severe Sepsis: A Case Control Study

    PubMed Central

    Souza-Fonseca-Guimaraes, Paulo; Guimaraes, Fernando; Natânia De Souza-Araujo, Caroline; Maria Boldrini Leite, Lidiane; Cristina Senegaglia, Alexandra; Nishiyama, Anita; Souza-Fonseca-Guimaraes, Fernando

    2017-01-01

    Sepsis is a complex systemic inflammatory syndrome, the most common cause of which is attributed to systemic underlying bacterial infection. The complete mechanisms of the dynamic pro- and anti-inflammatory processes underlying the pathophysiology of sepsis remain poorly understood. Natural killer (NK) cells play a crucial role in the pathophysiology of sepsis, leading to exaggerated inflammation due their rapid response and production of pro-inflammatory cytokines such as interferon gamma (IFN-γ). Several studies have already shown that NK cells undergo lymphopenia in the peripheral blood of patients with sepsis. However, our understanding of the mechanisms behind its cellular trafficking and its role in disease development is restricted to studies in animal models. In this study, we aimed to compare the human NK cell subset (CD56bright or dim) levels in the peripheral blood and bronchoalveolar lavage (BAL) fluid of sepsis patients. We conducted a case-control study with a sample size consisting of 10 control patients and 23 sepsis patients enrolled at the Hospital Cajuru (Curitiba/PR, Brazil) from 2013 to 2015. Although we were able to confirm previous observations of peripheral blood lymphopenia, no significant differences were detected in NK cell levels in the BAL fluid of these patients. Overall, these findings strengthened the evidence that peripheral blood lymphopenia is likely to be associated with cell death as a consequence of sepsis. PMID:28287491

  13. Association between Vitamin D Status and Coronary Heart Disease among Adults in Saudi Arabia: A Case-Control Study.

    PubMed

    Aljefree, Najlaa M; Lee, Patricia; Alsaqqaf, Jamal M; Ahmed, Faruk

    2016-10-17

    Recent evidence has pointed out an association between vitamin D deficiency and coronary heart disease (CHD). Due to the growing epidemic of CHD and vitamin D deficiency in Saudi Arabia, exploring the role of vitamin D in the prevention of CHD is crucial. The aim of this study was to examine the association between vitamin D status and CHD in Saudi Arabian adults. This case-control study included 130 CHD cases and 195 age-sex matched controls. Study subjects were recruited from three hospitals in the western region of Saudi Arabia. Study participants were interviewed face-to-face to collect data on their socio-demographic characteristics and family history of CHD. Fasting blood samples were collected, and serum levels of vitamin D, glucose, and total cholesterol were measured. Body weight, height, and blood pressure measurements were also recorded. Severe vitamin D deficiency (25(OH)D < 10 ng/mL) was much more prevalent in CHD cases than in controls (46% and 3%, respectively). The results of multivariate logistic regression showed that vitamin D deficiency (25(OH)D < 20 ng/mL) was associated with CHD, with an odds ratio of 6.5 (95% CI: 2.7-15, p < 0.001). The current study revealed that vitamin D deficiency is independently associated with CHD, suggesting an important predictor of CHD among Saudi adults.

  14. Blood fatty acid patterns are associated with prostate cancer risk in a prospective nested case-control study

    PubMed Central

    Yang, Meng; Ayuningtyas, Azalea; Kenfield, Stacey A.; Sesso, Howard D.; Campos, Hannia; Ma, Jing; Stampfer1, Meir J.; Chavarro, Jorge E.

    2016-01-01

    Background Circulating fatty acids are highly correlated with each other and analyzing fatty acid patterns could better capture their interactions and their relation to prostate cancer. We aimed to assess the associations between data-derived blood fatty acid patterns and prostate cancer risk. Methods We conducted a nested case-control study in the Physicians’ Health Study. Fatty acids levels were measured in whole blood samples of 476 cases and their matched controls by age and smoking status. Fatty acid patterns were identified using principal component analysis. Conditional logistic regression was used to estimate odds ratio (OR) and 95% confidence interval (CI). Results Two patterns explaining 40.9% of total variation in blood fatty acid levels were identified. Pattern 1, which mainly reflects polyunsaturated fatty acid metabolism, was suggestively positively related to prostate cancer risk (ORquintile 5 vs. quintile 1=1.37, 95%CI=0.91–2.05, Ptrend=0.07). Pattern 2, which largely reflects de novo lipogenesis, was significantly associated with higher prostate cancer risk (ORquintile5 vs quintile1=1.63, 95%CI=1.04–2.55, Ptrend=0.02). This association was similar across tumor stage, grade, clinical aggressiveness categories and follow-up time. Conclusion The two patterns of fatty acids we identified were consistent with known interactions between fatty acid intake and metabolism. A pattern suggestive of higher activity in the de novo lipogenesis pathway was related to higher risk of prostate cancer. PMID:27488836

  15. DNA repair gene XRCC3 Thr241Met polymorphism and susceptibility to glioma: A case-control study.

    PubMed

    Xu, Gaofeng; Wang, Maode; Xie, Wanfu; Bai, Xiaobin

    2014-08-01

    The DNA repair gene, X-ray repair cross-complementing group 3 (XRCC3) Thr241Met polymorphism may be associated with a susceptibility to glioma. The present study aimed to investigate the association between the XRCC3 Thr241Met polymorphism and the potential susceptibility to gliomas. A hospital-based case-control study was conducted, which included a total of 886 patients with glioma and 886 healthy control subjects. Peripheral blood samples were extracted and the polymerase chain reaction-restriction fragment length polymorphism method was performed to analyze the genotypes. The glioma patients had a significantly higher frequency of the XRCC3 241 MetMet genotype [odds ratio (OR) = 1.62; 95% confidence interval (CI): 1.09-2.41; P=0.02] compared with the control subjects. When stratified by the grade of the glioma, the patients with stage IV glioma (according to the World Health Organization classification) had a significantly higher frequency of the XRCC3 241 MetMet genotype (OR=1.61; 95% CI: 1.06-2.44; P=0.03). When stratified by the histology of the glioma, there was no significant difference in the distribution of each genotype. The findings of the present study indicate that the XRCC3 Thr241Met polymorphism is associated with a susceptibility to glioma.

  16. 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.

  17. A Case-Control Study of the Association between Polymorphisms in the Fibrinogen Alpha Chain Gene and Schizophrenia

    PubMed Central

    2017-01-01

    Our previous studies using the mass spectrum analysis provided evidence that fibrinopeptide A (FPA) could be a potential biomarker for schizophrenia diagnosis. We sought further to demonstrate that variants in the fibrinogen alpha chain gene (FGA) coded FPA might confer vulnerability to schizophrenia. 1,145 patients with schizophrenia and 1,016 healthy volunteers from the Han population in Northeast China were recruited. The association of three tag single nucleotide polymorphisms (SNPs) (rs2070011 in the 5′UTR, rs2070016 in intron 4, and rs2070022 in the 3′UTR) in FGA and schizophrenia was examined using a case-control study design. Genotypic distributions of these three SNPs were not found to be significantly different between cases and controls (rs2070011: χ2 = 1.28, P = 0.528; rs2070016: χ2 = 4.11, P = 0.128; rs2070022: χ2 = 1.23, P = 0.541). There were also no significant differences in SNP allelic frequencies between cases and controls (all P > 0.05). Additionally, the frequency of haplotypes consisting of alleles of these three SNPs was not significantly different between cases and healthy control subjects (global χ2 = 9.27, P = 0.159). Our study did not show a significant association of FGA SNPs with schizophrenia. Future studies may need to test more FGA SNPs in a larger sample to identify those SNPs with a minor or moderate effect on schizophrenia. PMID:28203040

  18. Hyperactivity of the default-mode network in first-episode, drug-naive schizophrenia at rest revealed by family-based case-control and traditional case-control designs.

    PubMed

    Guo, Wenbin; Liu, Feng; Chen, Jindong; Wu, Renrong; Li, Lehua; Zhang, Zhikun; Chen, Huafu; Zhao, Jingping

    2017-03-01

    Abnormal regional activity and functional connectivity of the default-mode network (DMN) have been reported in schizophrenia. However, previous studies may have been biased by unmatched case-control design. To limit such bias, the present study used both the family-based case-control design and the traditional case-control design to investigate abnormal regional activity of the DMN in patients with schizophrenia at rest.Twenty-eight first-episode, drug-naive patients with schizophrenia, 28 age-, sex-matched unaffected siblings of the patients (family-based controls, FBC), and 40 healthy controls (HC) underwent resting-state functional magnetic resonance imaging (fMRI) scans. The group-independent component analysis and fractional amplitude of low-frequency fluctuation (fALFF) methods were used to analyze the data.Patients with schizophrenia show increased fALFF in an overlapped region of the right superior medial prefrontal cortex (MPFC) relative to the FBC and the HC. Compared with the HC, the patients and the FBC exhibit increased fALFF in an overlapped region of the left posterior cingulate cortex/precuneus (PCC/PCu). Furthermore, the z values of the 2 overlapped regions can separate the patients from the FBC/HC, and separate the patients/FBC from the HC with relatively high sensitivity and specificity.Both the family-based case-control and traditional case-control designs reveal hyperactivity of the DMN in first-episode, drug-naive patients with paranoid schizophrenia, which highlights the importance of the DMN in the neurobiology of schizophrenia. Family-based case-control design can limit the confounding effects of environmental factors in schizophrenia. Combination of the family-based case-control and traditional case-control designs may be a viable option for the neuroimaging studies.

  19. 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

  20. 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

  1. 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

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

    PubMed

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

    2011-04-01

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

  3. 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

  4. 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

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

    PubMed Central

    de Groh, Margaret; Morrison, Howard

    2017-01-01

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

  6. 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.

  7. 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.

  8. 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.

  9. Bridging ImmunoGenomic Data Analysis Workflow Gaps (BIGDAWG): An integrated case-control analysis pipeline.

    PubMed

    Pappas, Derek J; Marin, Wesley; Hollenbach, Jill A; Mack, Steven J

    2016-03-01

    Bridging ImmunoGenomic Data-Analysis Workflow Gaps (BIGDAWG) is an integrated data-analysis pipeline designed for the standardized analysis of highly-polymorphic genetic data, specifically for the HLA and KIR genetic systems. Most modern genetic analysis programs are designed for the analysis of single nucleotide polymorphisms, but the highly polymorphic nature of HLA and KIR data require specialized methods of data analysis. BIGDAWG performs case-control data analyses of highly polymorphic genotype data characteristic of the HLA and KIR loci. BIGDAWG performs tests for Hardy-Weinberg equilibrium, calculates allele frequencies and bins low-frequency alleles for k×2 and 2×2 chi-squared tests, and calculates odds ratios, confidence intervals and p-values for each allele. When multi-locus genotype data are available, BIGDAWG estimates user-specified haplotypes and performs the same binning and statistical calculations for each haplotype. For the HLA loci, BIGDAWG performs the same analyses at the individual amino-acid level. Finally, BIGDAWG generates figures and tables for each of these comparisons. BIGDAWG obviates the error-prone reformatting needed to traffic data between multiple programs, and streamlines and standardizes the data-analysis process for case-control studies of highly polymorphic data. BIGDAWG has been implemented as the bigdawg R package and as a free web application at bigdawg.immunogenomics.org.

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

    PubMed

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

    2004-04-05

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

  11. 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.

  12. Alveolar Ridge Reconstruction with Titanium Meshes and Simultaneous Implant Placement: A Retrospective, Multicenter Clinical Study

    PubMed Central

    Paraud Freixas, Andres; Han, Chang-Hun; Bechara, Sohueil; Tawil, Isaac

    2016-01-01

    Objective. To evaluate horizontal bone gain and implant survival and complication rates in patients treated with titanium meshes placed simultaneously with dental implants and fixed over them. Methods. Twenty-five patients treated with 40 implants and simultaneous guided bone regeneration with titanium meshes (i–Gen®, MegaGen, Gyeongbuk, Republic of Korea) were selected for inclusion in the present retrospective multicenter study. Primary outcomes were horizontal bone gain and implant survival; secondary outcomes were biological and prosthetic complications. Results. After the removal of titanium meshes, the CBCT evaluation revealed a mean horizontal bone gain of 3.67 mm (±0.89). The most frequent complications were mild postoperative edema (12/25 patients: 48%) and discomfort after surgery (10/25 patients: 40%); these complications were resolved within one week. Titanium mesh exposure occurred in 6 patients (6/25 : 24%): one of these suffered partial loss of the graft and another experienced complete graft loss and implant failure. An implant survival rate of 97.5% (implant-based) and a peri-implant marginal bone loss of 0.43 mm (±0.15) were recorded after 1 year. Conclusions. The horizontal ridge reconstruction with titanium meshes placed simultaneously with dental implants achieved predictable satisfactory results. Prospective randomized controlled trials on a larger sample of patients are required to validate these positive outcomes. PMID:27999799

  13. Reappraisal of known malaria resistance loci in a large multicenter study.

    PubMed

    2014-11-01

    Many human genetic associations with resistance to malaria have been reported, but few have been reliably replicated. We collected data on 11,890 cases of severe malaria due to Plasmodium falciparum and 17,441 controls from 12 locations in Africa, Asia and Oceania. We tested 55 SNPs in 27 loci previously reported to associate with severe malaria. There was evidence of association at P < 1 × 10(-4) with the HBB, ABO, ATP2B4, G6PD and CD40LG loci, but previously reported associations at 22 other loci did not replicate in the multicenter analysis. The large sample size made it possible to identify authentic genetic effects that are heterogeneous across populations or phenotypes, with a striking example being the main African form of G6PD deficiency, which reduced the risk of cerebral malaria but increased the risk of severe malarial anemia. The finding that G6PD deficiency has opposing effects on different fatal complications of P. falciparum infection indicates that the evolutionary origins of this common human genetic disorder are more complex than previously supposed.

  14. Alveolar Ridge Reconstruction with Titanium Meshes and Simultaneous Implant Placement: A Retrospective, Multicenter Clinical Study.

    PubMed

    Zita Gomes, Raquel; Paraud Freixas, Andres; Han, Chang-Hun; Bechara, Sohueil; Tawil, Isaac

    2016-01-01

    Objective. To evaluate horizontal bone gain and implant survival and complication rates in patients treated with titanium meshes placed simultaneously with dental implants and fixed over them. Methods. Twenty-five patients treated with 40 implants and simultaneous guided bone regeneration with titanium meshes (i-Gen®, MegaGen, Gyeongbuk, Republic of Korea) were selected for inclusion in the present retrospective multicenter study. Primary outcomes were horizontal bone gain and implant survival; secondary outcomes were biological and prosthetic complications. Results. After the removal of titanium meshes, the CBCT evaluation revealed a mean horizontal bone gain of 3.67 mm (±0.89). The most frequent complications were mild postoperative edema (12/25 patients: 48%) and discomfort after surgery (10/25 patients: 40%); these complications were resolved within one week. Titanium mesh exposure occurred in 6 patients (6/25 : 24%): one of these suffered partial loss of the graft and another experienced complete graft loss and implant failure. An implant survival rate of 97.5% (implant-based) and a peri-implant marginal bone loss of 0.43 mm (±0.15) were recorded after 1 year. Conclusions. The horizontal ridge reconstruction with titanium meshes placed simultaneously with dental implants achieved predictable satisfactory results. Prospective randomized controlled trials on a larger sample of patients are required to validate these positive outcomes.

  15. Laparoscopic versus open adhesiolysis for small bowel obstruction - a multicenter, prospective, randomized, controlled trial

    PubMed Central

    2014-01-01

    Background Laparoscopic adhesiolysis is emerging as an alternative for open surgery in adhesive small bowel obstruction. Retrospective studies suggest that laparoscopic approach shortens hospital stay and reduces complications in these patients. However, no prospective, randomized, controlled trials comparing laparoscopy to open surgery have been published. Methods/Design This is a multicenter, prospective, open label, randomized, controlled trial comparing laparoscopic adhesiolysis to open surgery in patients with computed-tomography diagnosed adhesive small bowel obstruction that is not resolving with conservative management. The primary study endpoint is the length of postoperative hospital stay in days. Sample size was estimated based on preliminary retrospective cohort, which suggested that 102 patients would provide 80% power to detect a difference of 2.5 days in the length of postoperative hospital stay with significance level of 0.05. Secondary endpoints include passage of stool, commencement of enteral nutrition, 30-day mortality, complications, postoperative pain, and the length of sick leave. Tertiary endpoints consist of the rate of ventral hernia and the recurrence of small bowel obstruction during long-term follow-up. Long-term follow-up by letter or telephone interview will take place at 1, 5, and 10 years. Discussion To the best of our knowledge, this trial is the first one aiming to provide level Ib evidence to assess the use of laparoscopy in the treatment of adhesive small bowel obstruction. Trial registration ClinicalTrials.gov identifier: NCT01867528. Date of registration May 26th 2013. PMID:25306234

  16. Multicenter evaluation of the interference of hemoglobin, bilirubin and lipids on Synchron LX-20 assays.

    PubMed

    Steen, Gerard; Vermeer, Henricus J; Naus, André J M; Goevaerts, Berrie; Agricola, Pauline T; Schoenmakers, Christian H H

    2006-01-01

    The influence of interference by hemolysis, icterus and lipemia on the results of routine chemistries may lead to wrong interpretations. The H-, I- and L-indices that can be measured by the Beckman LX-20 instrument (Beckman Coulter) in serum or plasma samples are a reliable semi-quantitative measure of the size of these interferences. A survey carried out in 16 Dutch clinical laboratories on the use of these indices demonstrated that in several of these laboratories, the influence of interferences is largely underestimated. Therefore, a multicenter study was carried out in which we examined the interference of hemolysis, icterus and lipemia on 32 analytes. On the basis of biological variation, we decided on cutoff indices above which analytically significant interference exists. We found analytically significant interference by hemolysis, icterus or lipemia, in 12, 7 and 15 of the 32 analytes studied, respectively. Flagging of results on the basis of analytically significant interference, however, results in too many clinically insignificant comments. On the basis of clinical significance, we conclude that significant interference by hemolysis, icterus or lipemia is present in only 5, 6 and 12 of the analytes studied, respectively. Use of the cutoff indices presented here facilitates optimal use of the LX-20 indices to prevent reporting of wrong results due to interference.

  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.

  19. Human leukocyte antigen polymorphisms in Italian primary biliary cirrhosis: a multicenter study of 664 patients and 1992 healthy controls

    PubMed Central

    Invernizzi, Pietro; Selmi, Carlo; Poli, Francesca; Frison, Sara; Floreani, Annarosa; Alvaro, Domenico; Almasio, Piero; Rosina, Floriano; Marzioni, Marco; Fabris, Luca; Muratori, Luigi; Qi, Lihong; Seldin, Michael F.; Gershwin, M. Eric; Podda, Mauro

    2008-01-01

    Genetic factors are critical in determining susceptibility to primary biliary cirrhosis (PBC), but there has not been a clear association with human leukocyte antigen (HLA) genes. We performed a multi-center case-control study and analyzed HLA class II DRB1 associations using a large cohort of 664 well-defined cases of PBC and 1,992 controls of Italian ancestry. Importantly, healthy controls were rigorously matched not only by age and gender, but also for the geographical origin of the proband four grandparents (Northern, Central, and Southern Italy). Following correction for multiple testing, DRB1*08 (Odds Ratio–OR, 3.3; 95% Confidence Interval–CI, 2.4−4.5) and DRB1*02 (OR 0.9; 95% CI 0.8−1.2) were significantly associated with PBC while alleles DRB1*11 (OR 0.4; 95% CI 0.3−0.4) and DRB1*13 (OR 0.7; 95% CI 0.6−0.9) were protective. When subjects were stratified according to their grandparental geographical origin, only the associations with DRB1*08 and DRB1*11 were common to all three areas. Associated DRB1 alleles were found only in a minority of patients while an additive genetic model is supported by the gene dosage effect for DRB1*11 allele and the interaction of DRB1*11,*13, and *08. Lastly, no significant associations were detected between specific DRB1 alleles and relevant clinical features represented by the presence of cirrhosis or serum autoantibodies. In conclusion, we confirm the role for HLA to determine PBC susceptibility and suggest that the effect of HLA is limited to patient subgroups. We suggest that a large whole-genome approach is required to identify further genetic elements contributing to the loss of tolerance in this disease. PMID:19003916

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

    PubMed

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

    2015-03-01

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

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

    PubMed

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

    2012-04-01

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

  2. Elevated Serum Levels of Retinol-Binding Protein 4 Are Associated with Breast Cancer Risk: A Case-Control Study

    PubMed Central

    Ma, Aiguo; Li, Na; Si, Hongzong

    2016-01-01

    Background Retinol binding protein 4 (RBP4) is a recently identified adipokine that is elevated in patients with obesity or type 2 diabetes. A growing body of research has shown that RBP4 is associated with several types of cancer. However, no studies have investigated the relationship between serum RBP4 levels and breast cancer risk. We performed a case-control study to evaluate the association between serum RBP4 levels and the risk of breast cancer. Methods From August 2012 to December 2013, four-hundred subjects including 200 patients diagnosed with primary breast cancer and 200 matched healthy women were consecutively enrolled from Affiliated Hospital of Qingdao University Medical College. Blood samples were collected from healthy controls and breast cancer patients before commencement of treatment. Enzyme-linked immunosorbent assay was used to evaluate the serum RBP4 levels in separated serum samples. Meanwhile, the characteristics of breast cancer cases and controls were collected from medical records and pathological data. Results The serum levels of RBP4 were significantly higher in patients with breast cancer than that in the healthy control group (33.77±9.92 vs. 28.77±6.47μg/ml, P < 0.05). Compared to the subjects in the lowest quartile of serum RBP4 level, the adjusted ORs (95% CIs) is 2.16(1.01–4.61) and 2.07 (1.07–4.00) for women in the second and highest RBP4 tertile, respectively. For breast cancer patients, patients with PR or ER negative displayed significantly higher serum RBP4 levels than those with PR or ER positive. Conclusion Our results for the first time suggested serum RBP4 levels could be associated with the risk of breast cancer. However, further prospective studies are essential to confirm these observed results. PMID:28002423

  3. Evaluation of 6 candidate genes on chromosome 11q23 for coeliac disease susceptibility: a case control study

    PubMed Central

    2010-01-01

    Background Recent whole genome analysis and follow-up studies have identified many new risk variants for coeliac disease (CD, gluten intolerance). The majority of newly associated regions encode candidate genes with a clear functional role in T-cell regulation. Furthermore, the newly discovered risk loci, together with the well established HLA locus, account for less than 50% of the heritability of CD, suggesting that numerous additional loci remain undiscovered. Linkage studies have identified some well-replicated risk regions, most notably chromosome 5q31 and 11q23. Methods We have evaluated six candidate genes in one of these regions (11q23), namely CD3E, CD3D, CD3G, IL10RA, THY1 and IL18, as risk factors for CD using a 2-phase candidate gene approach directed at chromosome 11q. 377 CD cases and 349 ethnically matched controls were used in the initial screening, followed by an extended sample of 171 additional coeliac cases and 536 additional controls. Results Promotor SNPs (-607, -137) in the IL18 gene, which has shown association with several autoimmune diseases, initially suggested association with CD (P < 0.05). Follow-up analyses of an extended sample supported the same, moderate effect (P < 0.05) for one of these. Haplotype analysis of IL18-137/-607 also supported this effect, primarily due to one relatively rare haplotype IL18-607C/-137C (P < 0.0001), which was independently associated in two case-control comparisons. This same haplotype has been noted in rheumatoid arthritis. Conclusion Haplotypes of the IL18 promotor region may contribute to CD risk, consistent with this cytokine's role in maintaining inflammation in active CD. PMID:20478055

  4. Nontyphoidal Salmonella Gastroenteritis in Baoshan, Shanghai, China, 2010 to 2014: An Etiological Surveillance and Case-Control Study.

    PubMed

    Yang, Xingtang; Jin, Kai; Yang, Fan; Yuan, Guoping; Liu, Wenbin; Xiang, Lunhui; Wu, Zhenqiang; Li, Zixiong; Mao, Jianying; Shen, Junqing; Lombe, Nelson; Zandamela, Hemitério; Hazoume, Lucrece; Hou, Xiaomei; Ding, Yibo; Cao, Guangwen

    2017-03-01

    Nontyphoidal Salmonella (NTS) gastroenteritis is a widespread global foodborne disease. To identify the epidemiologic characteristics, sources of food contamination, and risk factors of NTS gastroenteritis, epidemiologic data and stool specimens of diarrheal patients were collected from sentinel hospitals in Baoshan, Shanghai, People's Republic of China, between 2010 and 2014. Food products from nearby farmers' markets and animal feces from live poultry markets and livestock farms were sampled to identify the pathogen; a case-control study was conducted to characterize risk factors of NTS gastroenteritis. Of 3,906 diarrheal patients examined, 266 (6.8%) were positive for Salmonella. The positive rates were higher in summer than in the other seasons. Salmonella Typhimurium (36.1%) and Salmonella Enteritidis (30.8%) were the dominant serovars in the patients. Salmonella was detected in 26.2% pork samples, 7.1 to 7.8% poultry meats, and 3.3 to 8.9% poultry feces. Salmonella Typhimurium was the major serovar in contaminated food and animal feces. Multivariate conditional logistic regression analysis indicated that consumption of pork and quickly cooked eggs increased, whereas separating kitchen knives for cooked and raw food decreased the risk of NTS gastroenteritis, independently. We believe that NTS in poultry feces contaminated the meat products in the same markets and then infected humans if these foods were not sufficiently cooked. To prevent NTS gastroenteritis, it is necessary to survey Salmonella in meats and poultry feces, to cook eggs and pork sufficiently, to separate kitchen knives for cooked and raw food, and to prohibit live poultry trade in fresh meat markets.

  5. Human papilloma virus 16-18 infection and cervical cancer in Mexico: a case-control study.

    PubMed

    Hernández-Avila, M; Lazcano-Ponce, E C; Berumen-Campos, J; Cruz-Valdéz, A; Alonso de Ruíz, P P; Gonźalez-Lira, G

    1997-01-01

    Cervical cancer (CC) is one of the principal public health problems in Mexico. The national mortality rate due to CC was estimated at 21.8 per 100,000 among women over 15 years old during 1994. Despite this high incidence little is known in Mexico about the risk factors for CC. The objectives of the study were to evaluate the association between CC and HPV types 16 and 18 in women living in Mexico City. From August, 1990 to December, 1992, a case-control study was carried out in the metropolitan area of Mexico City. HPV 16-18 types were determined in a sample of 148 CC cases and 204 controls randomly selected from a sample frame representative of the metropolitan area of Mexico City. Sixty cases corresponded to in situ CC and 88 cases to the invasive phase. Determination of HPV 16 and 18 types was done by polymerase chain reaction using primers specific to E6/E7. Results showed that 48.3% of in situ CC cases and 48.8% of invasive CC cases were positive for HPV 16 while only 13.2% were positive among the 204 controls. Association between HPV 16 infection in the in situ cancer cases had an estimated odds ratio (OR) of 5.17 (95% CI 2.60-10.51). In the invasive cervical cancer cases, association between HPV 16 infection and invasive CC in this sample had an OR of 3.84 (95% CI 2.04-7.22). For the total sample, the estimated OR was 5.48 (95% CI 3.07-9.62). In the total sample, those women with a strong positive reaction to PCR were associated with a large increase in the risk, OR of 38.0 (95% CI 8.66-167.1). The prevalence the HPV 18 was 6.7%, only observed in the invasive cervical cancer cases. At present there is general consensus that HPV is the principal causal agent in C C etiology. This study intends to contribute to the knowledge concerning the etiology of cervical cancer. However, it is necessary to consider that the single most effective tool in the reduction of mortality due to cervical cancer has been the Pap test. Secondary prevention has proven to be highly

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

    PubMed Central

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

    2016-01-01

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

  7. The association between component malalignment and post-operative pain following navigation-assisted total knee arthroplasty: results of a cohort/nested case-control study.

    PubMed

    Czurda, Thomas; Fennema, Peter; Baumgartner, Martin; Ritschl, Peter

    2010-07-01

    Previous studies have noted an adverse relationship between implant malalignment during total knee arthroplasty (TKA) and post-operative pain. Although some evidence exists indicating that computer-assisted surgical navigation for TKA can improve the accuracy of component alignment, its impact on clinical outcomes is currently unknown. The dual goals of the present cohort/nested case-control study were to (1) compare self-reported responses to the Western Ontario-McMaster Osteoarthritis Index (WOMAC) questionnaire between computer-assisted TKA (123 patients) using the imageless PiGalileo navigation system and conventional TKA (207 patients) [cohort analysis], and (2) to investigate a potential association between malalignment and post-operative pain in 19 painful knees and 19 asymptomatic knees obtained from the cohort analysis using matched sampling [nested case-control study]. In the cohort analysis, a relevant but non-significant (P = 0.06) difference in the occurrence of chronic pain was observed between the navigated (12%) and conventional arms (20%). Median post-operative WOMAC pain score was 100 (range, 50-100) in the conventional group and 100 (range, 65-100) in the navigated group. However, the Mann-Whitney test revealed a significant difference in favor of the navigated group (P = 0.01). In the nested case-control analysis, radiological outcomes and computer tomography (CT) measurements of femoral rotation were compared between the groups. The CT rotation measurements yielded evidence of a relationship between post-operative pain and incorrect rotational alignment of the femoral component of more than 3 degrees (OR: 7; 95% CI: 1.2-42; P = .033). In conclusion, there was no clinical benefit to computer-assisted navigation; however, a statistically significant relationship was observed between incorrect rotational alignment of the femoral component and symptoms of post-operative pain following TKA.

  8. 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

  9. An open multicenter comparative randomized clinical study on chitosan.

    PubMed

    Mo, Xiaohui; Cen, John; Gibson, Elaine; Wang, Robin; Percival, Steven L

    2015-01-01

    Chitosan, a natural polysaccharide derivate from chitin, offers a promising alternative biomaterial for use in wound dressings. In this work, the safety and efficacy of a next-generation KA01 chitosan wound dressing in facilitating the healing of nonhealing chronic wounds was studied. This open multicenter comparative prospective randomized clinical study was conducted at three medical centers in China. A total of 90 patients (45 in test group and 45 in control group) with unhealed chronic wounds including pressure ulcers, vascular ulcers, diabetic foot ulcers, and wounds with minor infections, or at risk of infection, were treated with the next generation chitosan wound dressing as the test article or traditional vaseline gauze as a control. Baseline assessments were undertaken with the primary end point being wound area reduction. The secondary end points included pain reduction (using the NRS11 pain scale) at dressing change, wound exudate levels, wound depth and duration of the treatment. After 4 weeks treatment, the wound area reduction was significantly greater in the test group (65.97 ± 4.48%) than the control group (39.95 ± 4.48%). The average pain level in the test group was 1.12 ± 0.23 and 2.30 ± 0.23 in the control group. The wound depth was also lower in the test group 0.30 ± 0.48 cm than the control group 0.54 ± 0.86 cm. The level of exudate fell and the dressing could be removed integrally in both the test and control groups. The mean duration of the test group was 27.31 ± 5.37 days and control group 27.09 ± 6.44 days. No adverse events were reported in either group. In conclusion this open multicenter comparative prospective randomized clinical study has provided compelling evidence that the next generation chitosan wound dressing can enhance wound progression towards healing by facilitating wound reepithelialization and reducing the patients pain level. Furthermore the dressing was shown to be clinically safe and effective in the management

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

    PubMed

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

    2015-01-01

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

  11. Carcinogenicity of chrysotile asbestos: a case control study of textile workers

    SciTech Connect

    Dement, J.M. )

    1991-01-01

    Chrysotile is the predominant type of asbestos used in the United States and thus represents the most important source of exposure to asbestos already in place. While the steepest exposure-response observed for lung cancer has been in workers exposed to chrysotile in textile operations, some argue that chrysotile is less carcinogenic than amphibole asbestos types. Mineral oil exposures have been hypothesized to be responsible for the highly elevated lung cancer risk seen in textile workers. A lung cancer case-control analysis among a cohort of South Carolina chrysotile asbestos textile workers was conducted. Only a modest reduction in the slope of the lung cancer exposure-response relationship was observed after controlling for mineral oil exposures. These data do not support mineral oil exposure as a plausible explanation for the elevated lung cancer risk seen in chrysotile asbestos textile workers. The possible role of longer, thinner, more carcinogenic fibers in textiles is one plausible hypothesis needing further investigation.

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

    PubMed

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

    1996-07-01

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

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

    SciTech Connect

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

    1988-03-01

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

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

    PubMed

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

    1988-01-01

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

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

    PubMed

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

    2014-09-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2002-01-01

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

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

    PubMed

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

    1998-11-01

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

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

    PubMed

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

    2012-01-01

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

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

    PubMed

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

    2013-02-01

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

  1. 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.

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

    PubMed Central

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

    2009-01-01

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

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

    PubMed Central

    Ferns, Lyn; Dohoo, Ian; Donald, Alan

    1991-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2006-10-01

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

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

    PubMed Central

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

    2015-01-01

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

  7. Point source modeling of matched case-control data with multiple disease subtypes.

    PubMed

    Li, Shi; Mukherjee, Bhramar; Batterman, Stuart

    2012-12-10

    In this paper, we propose nonlinear distance-odds models investigating elevated odds around point sources of exposure, under a matched case-control design where there are subtypes within cases. We consider models analogous to the polychotomous logit models and adjacent-category logit models for categorical outcomes and extend them to the nonlinear distance-odds context. We consider multiple point sources as well as covariate adjustments. We evaluate maximum likelihood, profile likelihood, iteratively reweighted least squares, and a hierarchical Bayesian approach using Markov chain Monte Carlo techniques under these distance-odds models. We compare these methods using an extensive simulation study and show that with multiple parameters and a nonlinear model, Bayesian methods have advantages in terms of estimation stability, precision, and interpretation. We illustrate the methods by analyzing Medicaid claims data corresponding to the pediatric asthma population in Detroit, Michigan, from 2004 to 2006.

  8. 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.

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

    PubMed

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

    2017-01-23

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

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

    PubMed

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

    2015-09-28

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

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

    PubMed

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

    2013-10-01

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

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

    PubMed

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

    2014-01-09

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

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

    PubMed

    Zhang, M D

    1993-02-01

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

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

    PubMed

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

    2014-01-01

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

  16. 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.

  17. "Virtual" clinical trials: case control experiments utilizing a health services research workstation.

    PubMed Central

    Weiner, M. G.; Hillman, A. L.

    1998-01-01

    We created an interface to a growing repository of clinical and administrative information to facilitate the design and execution of case-control experiments. The system enables knowledgeable users to generate and test hypotheses regarding associations among diseases and outcomes. The intuitive interface allows the user to specify criteria for selecting cases and defining putative risks. The repository contains comprehensive administrative and selected clinical information on all ambulatory and emergency department visits as well as hospital admissions since 1994. We tested the workstation's ability to determine relationships between outpatient diagnoses including hypertension, osteoarthritis and hypercholesterolemia with the occurrence of admissions for stroke and myocardial infarction and achieved results consistent with published studies. Successful implementation of this Health Services Research Workstation will allow "virtual" clinical trials to validate the results of formal clinical trials on a local population and may provide meaningful analyses of data when formal clinical trials are not feasible. PMID:9929230

  18. Rare occurrence of occult hepatitis C virus in apparently uninfected injecting drug users: a two-centre, masked, case-control study.

    PubMed

    Sugden, P B; Pham, T N Q; Ratnarajah, S; Cameron, B; Bull, R; White, P A; Michalak, T I; Lloyd, A R

    2013-10-01

    Occult hepatitis C virus (HCV) is a phenomenon where serum HCV RNA is not detected by sensitive commercial assays, but viral RNA is detected by ultrasensitive techniques. Occult HCV infection has not previously been studied in highly exposed, but apparently uninfected (EU) individuals. Two studies examining occult infection in EU subjects were undertaken - an initial two-centre, masked, case-control study based on cross-sectional samples (n = 35 subjects) and a single-centre confirmatory study based on longitudinal samples (n = 32 subjects). Plasma and peripheral blood mononuclear cells were tested for HCV RNA using an ultrasensitive nested polymerase chain reaction assays. Two EU subjects in the first study (10%) and one in the second study (3%) were found to have consistently detectable HCV RNA. Occult HCV infection occurs in high-risk, apparently uninfected subjects.

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

    PubMed Central

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

    2011-01-01

    Background Selective serotonin reuptake inhibitors (SSRIs) have been associated with upper gastrointestinal (GI) bleeding. Given their worldwide use, even small risks account for a large number of cases. This study has been conducted with carefully collected information to further investigate the relationship between SSRIs and upper GI bleeding. Methods We conducted a case-control study in hospitals in Spain and in Italy. Cases were patients aged ≥18 years with a primary diagnosis of acute upper GI bleeding diagnosed by endoscopy; three controls were matched by sex, age, date of admission (within 3 months) and hospital among patients who were admitted for elective surgery for non-painful disorders. Exposures to SSRIs, other antidepressants and other drugs were defined as any use of these drugs in the 7 days before the day on which upper gastrointestinal bleeding started (index day). Results 581 cases of upper GI bleeding and 1358 controls were considered eligible for the study; no differences in age or sex distribution were observed between cases and controls after matching. Overall, 4.0% of the cases and 3.3% of controls used an SSRI antidepressant in the week before the index day. No significant risk of upper GI bleeding was encountered for SSRI antidepressants (adjusted odds ratio, 1.06, 95% CI, 0.57–1.96) or for whichever other grouping of antidepressants. Conclusions The results of this case-control study showed no significant increase in upper GI bleeding with SSRIs and provide good evidence that the magnitude of any increase in risk is not greater than 2. PMID:21625637

  20. 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

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

    PubMed

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

    2000-01-01

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

  2. 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

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

    PubMed

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

    2013-09-01

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

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

    PubMed

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

    2010-11-01

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

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

    PubMed

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

    2016-01-01

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

  6. 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

  7. 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

  8. Emergency Care for Homeless Patients: A French Multicenter Cohort Study

    PubMed Central

    Feral-Pierssens, Anne-Laure; Aubry, Adeline; Truchot, Jennifer; Raynal, Pierre-Alexis; Boiffier, Mathieu; Hutin, Alice; Leleu, Agathe; Debruyne, Geraud; Joly, Luc-Marie; Juvin, Philippe; Riou, Bruno

    2016-01-01

    Objectives. To determine whether homeless patients experience suboptimal care in the emergency department (ED) by the provision of fewer health care resources. Methods. We conducted a prospective multicenter cohort study in 30 EDs in France. During 72 hours in March 2015, all homeless patients that visited the participating EDs were included in the study. The primary health care service measure was the order by the physician of a diagnostic investigation or provision of a treatment in the ED. Secondary measures of health care services included ED waiting time, number and type of investigations per patient, treatment in the ED, and discharge disposition. Results. A total of 254 homeless patients and 254 nonhomeless patients were included. After excluding homeless patients that attended the ED for the sole purpose of housing, we analyzed 214 homeless and 214 nonhomeless. We found no significant difference between the 2 groups in terms of health care resource consumption, and for our secondary endpoints. Conclusions. We did not find significant differences in the level of medical care delivered in French EDs to homeless patients compared with matched nonhomeless patients. PMID:26985613

  9. 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.

  10. Uterine rupture in pregnancies following myomectomy: A multicenter case series

    PubMed Central

    Kim, Hee-Sun; Oh, Soo-Young; Choi, Suk-Joo; Park, Hyun-Soo; Cho, Geum-Joon; Chung, Jin-Hoon; Seo, Yong-Soo; Jung, Sun-Young; Kim, Jung-Eun; Chae, Su-Hyun

    2016-01-01

    Objective The purpose of this case series was to retrospectively examine records of cases with uterine rupture in pregnancies following myomectomy and to describe the clinical features and pregnancy outcomes. Methods This study was conducted as a multicenter case series. The patient databases at 7 tertiary hospitals were queried. Records of patients with a diagnosis of uterine rupture in the pregnancy following myomectomy between January 2012 and December 2014 were retrospectively collected. The uterine rupture cases enrolled in this study were defined as follows: through-and-through uterine rupture or tear of the uterine muscle and serosa, occurrence from 24+0 to 41+6 weeks’ gestation, singleton pregnancy, and previous laparoscopic myomectomy (LSM) or laparotomic myomectomy (LTM) status. Results Fourteen pregnant women experienced uterine rupture during their pregnancy after LSM or LTM. Preterm delivery of less than 34 weeks’ gestation occurred in 5 cases, while intrauterine fetal death occurred in 3, and 3 cases had fetal distress. Of the 14 uterine rupture cases, none occurred during labor. All mothers survived and had no sequelae, unlike the perinatal outcomes, although they were receiving blood transfusion or treatment for uterine artery embolization because of uterine atony or massive hemorrhage. Conclusion In women of childbearing age who are scheduled to undergo LTM or LSM, the potential risk of uterine rupture on subsequent pregnancy should be explained before surgery. Pregnancy in women after myomectomy should be carefully observed, and they should be adequately counseled during this period. PMID:27896247

  11. Multicenter Australian trial of islet transplantation: improving accessibility and outcomes.

    PubMed

    O'Connell, P J; Holmes-Walker, D J; Goodman, D; Hawthorne, W J; Loudovaris, T; Gunton, J E; Thomas, H E; Grey, S T; Drogemuller, C J; Ward, G M; Torpy, D J; Coates, P T; Kay, T W

    2013-07-01

    Whilst initial rates of insulin independence following islet transplantation are encouraging, long-term function using the Edmonton Protocol remains a concern. The aim of this single-arm, multicenter study was to evaluate an immunosuppressive protocol of initial antithymocyte globulin (ATG), tacrolimus and mycophenolate mofetil (MMF) followed by switching to sirolimus and MMF. Islets were cultured for 24 h prior to transplantation. The primary end-point was an HbA1c of <7% and cessation of severe hypoglycemia. Seventeen recipients were followed for ≥ 12 months. Nine islet preparations were transported interstate for transplantation. Similar outcomes were achieved at all three centers. Fourteen of the 17 (82%) recipients achieved the primary end-point. Nine (53%) recipients achieved insulin independence for a median of 26 months (range 7-39 months) and 6 (35%) remain insulin independent. All recipients were C-peptide positive for at least 3 months. All subjects with unstimulated C-peptide >0.2 nmol/L had cessation of severe hypoglycemia. Nine of the 17 recipients tolerated switching from tacrolimus to sirolimus with similar graft outcomes. There was a small but significant reduction in renal function in the first 12 months. The combination of islet culture, ATG, tacrolimus and MMF is a viable alternative for islet transplantation.

  12. The current state of facial prosthetics – A multicenter analysis.

    PubMed

    Thiele, Oliver C; Brom, Jörn; Dunsche, Anton; Ehrenfeld, Michael; Federspil, Philippe; Frerich, Bernhard; Hölzle, Frank; Klein, Martin; Kreppel, Matthias; Kübler, Alexander C; Kübler, Norbert R; Kunkel, Martin; Kuttenberger, Johannes; Lauer, Günter; Mayer, Boris; Mohr, Christopher; Neff, Andreas; Rasse, Michael; Reich, Rudolf H; Reinert, Siegmar; Rothamel, Daniel; Sader, Robert; Schliephake, Henning; Schmelzeisen, Rainer; Schramm, Alexander; Sieg, Peter; Terheyden, Hendrik; Wiltfang, Jörg; Ziegler, Christoph M; Mischkowski, Robert A; Zöller, Joachim E

    2015-09-01

    Even though modern surgical techniques are dominating reconstructive facial procedures, the capability to use facial epitheses for reconstruction is still an important skill for the maxillofacial surgeon. We present an international multicenter analysis to clarify which techniques are used to fixate facial prostheses. We contacted all maxillofacial departments in Germany, Austria, Switzerland and Norway which were registered with the German society for oral and maxillofacial surgery (DGMKG). These centers were asked via electronical mail to provide information on the type of epithesis fixation systems currently in use. The return rate from 58 departments was 43.1% (n = 25). Overall, implant fixation was the preferred fixation system (92%). Plates were the second most common fixation technique (32%). No centers reported the standard use of non-invasive fixation techniques for permanent epithesis fixation. The main retention systems in use were magnets (24/25), other retention systems are used much less often. The current preferred fixation technique for facial epitheses consists of implant-based, magnet-fixated epitheses. For nasal prostheses, a plate-based, magnet-fixated system is often used.

  13. [National multicenter survey: the use of intravenous antimicrobial agents].

    PubMed

    Gutiérrez Zufiaurre, M N; García-Rodríguez, J A

    2006-12-01

    Infectious diseases are currently one of the major health problems worldwide. As a consequence, both nosocomial and community-acquired infections are responsible for a significant increase in workload and health costs for hospitals, particularly in Intensive Care Units (ICU), Internal Medicine and Surgery. The use of intravenous antimicrobial agents is common in hospitalized patients. In order to determine the use of antimicrobial agents and the most frequent procedures used for their administration in Spanish hospitals, a national multicenter survey was undertaken among ICU, Internal Medicine and Surgery health staff from 63 hospitals, in which data were collected on central and peripheral catheter manipulation and intravenous administration. Results showed that, in Spain, both catheter manipulation (insertion, maintenance and removal) and administration of antimicrobial agents are performed by the nursing staff following established protocols, particularly for central catheters. Moreover, the ICUs had the highest rates of catheter-bearing patients, as well as patients undergoing antimicrobial treatment, sometimes in combination. The use of intravenous antimicrobial agents in Spanish hospitals results in an increased workload for the nursing staff and higher health costs, not to mention the risk involved with the use of vascular catheters.

  14. Multi-center airborne coherent atmospheric wind sensor (MACAWS)

    SciTech Connect

    Rothermel, J.; Menzies, R.T.; Tratt, D.M.

    1996-11-01

    The Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS) is an airborne scanning coherent Doppler lidar designed to acquire remote multi-dimensional measurements of winds and absolute aerosol backscatter in the troposphere and lower stratosphere. These measurements enable study of atmospheric dynamic processes and features at scales of motion that may be undersampled by, or may be beyond the capability of, existing or planned sensors. MACAWS capabilities enable more realistic assessments of concepts in global tropospheric wind measurement with satellite Doppler lidar, as well as a unique capability to validate the NASA Scatterometer currently scheduled for launch in late 1996. MACAWS consists of a Joule-class CO{sub 2} coherent Doppler lidar on a ruggedized optical table, a programmable scanner to direct the lidar beam in the desired direction, and a dedicated inertial navigation system to account for variable aircraft attitude and speed. MACAWS was flown for the first time in September 1995, over the eastern Pacific Ocean and western US. 33 refs., 2 figs.

  15. Cardiac bioassist: results of the French multicenter cardiomyoplasty study.

    PubMed

    Chachques, Juan C; Jegaden, Olivier; Mesana, Thierry; Glock, Yves; Grandjean, Pierre A; Carpentier, Alain F

    2009-12-01

    The French multicenter experience (6 centers) of dynamic cardiomyoplasty was analyzed for long-term survival and functional outcome, the most important endpoints in congestive heart failure therapy. Cardiomyoplasty was performed in 212 patients with symptoms of chronic heart failure despite maximal pharmacological therapy. The etiology was ischemic (48%), idiopathic (45%) or other (7%). Cardiomyoplasty was performed using the latissimus dorsi muscle which was electrostimulated after surgery. During follow-up, 88% of patients improved clinically. Hospital death occurred in 29 (14%) patients and was related to the severity of preoperative heart failure symptoms. Late mortality occurred in 99 patients due to heart failure (44%), sudden death (37%), or noncardiac causes (18%). Combined dynamic cardiomyoplasty and implantation of a cardiac rhythm management system was safely achieved in 22 patients, and 26 underwent heart transplantation for recurrent heart failure. Long-term functional improvements were observed in most patients, and the best outcome was achieved in those with isolated right ventricular failure. Dynamic cardiomyoplasty can be considered as a destination therapy or a mid- to long-term biological bridge to heart transplantation.

  16. 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

  17. Cognitive-behavioral screening reveals prevalent impairment in a large multicenter ALS cohort

    PubMed Central

    Factor-Litvak, Pam; Goetz, Raymond; Lomen-Hoerth, Catherine; Nagy, Peter L.; Hupf, Jonathan; Singleton, Jessica; Woolley, Susan; Andrews, Howard; Heitzman, Daragh; Bedlack, Richard S.; Katz, Jonathan S.; Barohn, Richard J.; Sorenson, Eric J.; Oskarsson, Björn; Fernandes Filho, J. Americo M.; Kasarskis, Edward J.; Mozaffar, Tahseen; Rollins, Yvonne D.; Nations, Sharon P.; Swenson, Andrea J.; Koczon-Jaremko, Boguslawa A.; Mitsumoto, Hiroshi

    2016-01-01

    Objectives: To characterize the prevalence of cognitive and behavioral symptoms using a cognitive/behavioral screening battery in a large prospective multicenter study of amyotrophic lateral sclerosis (ALS). Methods: Two hundred seventy-four patients with ALS completed 2 validated cognitive screening tests and 2 validated behavioral interviews with accompanying caregivers. We examined the associations between cognitive and behavioral performance, demographic and clinical data, and C9orf72 mutation data. Results: Based on the ALS Cognitive Behavioral Screen cognitive score, 6.5% of the sample scored below the cutoff score for frontotemporal lobar dementia, 54.2% scored in a range consistent with ALS with mild cognitive impairment, and 39.2% scored in the normal range. The ALS Cognitive Behavioral Screen behavioral subscale identified 16.5% of the sample scoring below the dementia cutoff score, with an additional 14.1% scoring in the ALS behavioral impairment range, and 69.4% scoring in the normal range. Conclusions: This investigation revealed high levels of cognitive and behavioral impairment in patients with ALS within 18 months of symptom onset, comparable to prior investigations. This investigation illustrates the successful use and scientific value of adding a cognitive-behavioral screening tool in studies of motor neuron diseases, to provide neurologists with an efficient method to measure these common deficits and to understand how they relate to key clinical variables, when extensive neuropsychological examinations are unavailable. These tools, developed specifically for patients with motor impairment, may be particularly useful in patient populations with multiple sclerosis and Parkinson disease, who are known to have comorbid cognitive decline. PMID:26802094

  18. 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.

  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.

  20. Anxiety disorders and anxiety-related traits and serotonin transporter gene-linked polymorphic region (5-HTTLPR) in adolescents: case-control and trio studies.

    PubMed

    Bortoluzzi, Andressa; Blaya, Carolina; Salum, Giovanni A; Cappi, Carolina; Leistner-Segal, Sandra; Manfro, Gisele G

    2014-08-01

    The role of the serotonin transporter gene-linked polymorphic region (5-HTTLPR) in anxiety disorder and anxiety-related traits is controversial. Besides this study, few studies have evaluated the triallelic genotype in adolescents. The aim of this study was to investigate whether anxiety disorders and anxiety-related traits are associated with 5-HTTLPR (biallelic and triallelic) in adolescents, integrating both case-control-based and family-based designs in a community sample. This is a cross-sectional community study of 504 individuals and their families: 225 adolescents (129 adolescents with anxiety disorder and 96 controls) and their biological families. We assessed psychiatric diagnosis using the Kiddie Schedule for Affective Disorders and Schizophrenia. The Temperament and Character Inventory and the Resnick Behavioral Inhibition Scale were used to evaluate harm avoidance and behavioral inhibition. DNA was extracted from saliva and genotyped, including biallelic and triallelic 5-HTTLPR classification, by PCR-RFLP followed by agarose gel electrophoresis. We were not able to find any associations between 5-HTTLPR and anxiety-related phenotypes in both case-control and trio analyses. Further investigation and meta-analytic studies are needed to better clarify the inconsistent results with regard to the association between 5-HTTLPR and anxiety-related phenotypes in adolescents.

  1. Potential role of real-time PCR for detecting Mycobacterium avium subsp. paratuberculosis in chronically diseased milking cows: a case control study.

    PubMed

    Alajmi, Ahmad; Klein, Günter; Greiner, Matthias; Grabowski, Nils Th; Fohler, Svenja; Campe, Amely; Scheu, Theresa; Hoedemaker, Martina; Abdulmawjood, Amir

    2016-01-01

    Paratuberculosis caused by Mycobacterium avium subsp. paratuberculosis (MAP) is economically important to dairy operations. In the present study, a real-time PCR kit (certified for use in Germany) was used to detect MAP in bovine fecal and milk samples within a case control study examining different factors for their association with chronic disease in Northern Germany.The aim of this study was to describe the suitability of the MAP real-time PCR kit to detect MAP in feces and milk of chronically diseased dairy cows. For MAP detection a total of 928 fecal, 922 composite foremilk, and 92 bulk milk samples obtained from 58 cases and 35 control dairy herds were investigated. The real-time PCR showed MAP positive results for 11 (18.96%) and 6 (17.14%) of the case and control herds, respectively. All bulk milk samples were MAP negative. The results of fecal and milk samples were moderately correlated (kappa = 0.27). These data indicate that real-time PCR results have diagnostic value for diagnosing MAP positive animals, and that fecal samples are more suitable than milk samples for assessing the reasons for chronic disease on dairy farms.

  2. Rheumatoid Arthritis Was Negatively Associated with Alzheimer’s Disease: A Population-Based Case-Control Study

    PubMed Central

    Kao, Li-Ting; Kang, Jiunn-Horng; Lin, Herng-Ching

    2016-01-01

    Some of the prior literature investigated the potential association between rheumatoid arthritis (RA) and Alzheimer's disease (AD) because these two diseases may share similar inflammatory mechanisms. Nevertheless, to date, findings of the previous literature are still controversial, and some methodological limitations were observed in those studies. The aim of this case-control study was to investigate the relationship between prior RA and AD using a large population-based dataset. This study used the Taiwan Longitudinal Health Insurance Database 2005. We included 2271 patients with AD who had received prescriptions for acetylcholinesterase inhibitors (AChEIs) as cases and 6813 patients without AD as controls in this study. In addition, we performed a conditional logistic regression to examine the odds ratio (OR) and 95% confidence interval (CI) for prior RA between cases and controls. The study found that 330 (3.63%) of the total sampled patients had an RA diagnosis before the index date. Additionally, prior RA was found in 60 (2.64%) cases and in 270 (3.96%) controls. The conditional logistic regression analysis showed that the crude OR of prior RA for cases was 0.66 (95% confidence interval (CI): 0.49~0.87) compared to controls. After adjusting for patients’ geographic location, urbanization level, and comorbidities, the adjusted OR of prior RA for patients with AD was 0.73 (95% CI: 0.55~0.98) compared to those without AD. We concluded that there was an inverse association between prior RA and AD even after adjusting for potential confounders. PMID:27997574

  3. 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

  4. 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

  5. Restaurant outbreak of Legionnaires' disease associated with a decorative fountain: an environmental and case-control study

    PubMed Central

    O'Loughlin, Rosalyn E; Kightlinger, Lon; Werpy, Matthew C; Brown, Ellen; Stevens, Valerie; Hepper, Clark; Keane, Tim; Benson, Robert F; Fields, Barry S; Moore, Matthew R

    2007-01-01

    Background From June to November 2005, 18 cases of community-acquired Legionnaires' disease (LD) were reported in Rapid City South Dakota. We conducted epidemiologic and environmental investigations to identify the source of the outbreak. Methods We conducted a case-control study that included the first 13 cases and 52 controls randomly selected from emergency department records and matched on underlying illness. We collected information about activities of case-patients and controls during the 14 days before symptom onset. Environmental samples (n = 291) were cultured for Legionella. Clinical and environmental isolates were compared using monoclonal antibody subtyping and sequence based typing (SBT). Results Case-patients were significantly more likely than controls to have passed through several city areas that contained or were adjacent to areas with cooling towers positive for Legionella. Six of 11 case-patients (matched odds ratio (mOR) 32.7, 95% CI 4.7-∞) reported eating in Restaurant A versus 0 controls. Legionella pneumophila serogroup 1 was isolated from four clinical specimens: 3 were Benidorm type strains and 1 was a Denver type strain. Legionella were identified from several environmental sites including 24 (56%) of 43 cooling towers tested, but only one site, a small decorative fountain in Restaurant A, contained Benidorm, the outbreak strain. Clinical and environmental Benidorm isolates had identical SBT patterns. Conclusion This is the first time that small fountain without obvious aerosol-generating capability has been implicated as the source of a LD outbreak. Removal of the fountain halted transmission. PMID:17688692

  6. Plasma glutathione peroxidase (GSH-Px) concentration is elevated in rheumatoid arthritis: a case-control study.

    PubMed

    Jacobson, Glenn A; Ives, Stephen J; Narkowicz, Christian; Jones, Graeme

    2012-11-01

    Plasma glutathione peroxidase (GSH-Px) by enzyme-linked immunosorbent assay (ELISA) offers a complimentary measurement approach to traditional GSH-Px activity methods. The aim was to investigate whether GSH-Px measured by ELISA in rheumatoid arthritis patients was elevated compared to controls. This was a case-control study with rheumatoid arthritis patients recruited from private practice and gender and age-matched controls randomly selected from the electoral role. GSH-Px concentration was measured by ELISA. Plasma malondialdehyde was used as a measure of oxidative stress, and antioxidant capacity was measured based on reduction of Cu(++) to Cu(+) by antioxidants in the sample. Disease severity was measured using the Health Assessment Questionnaire-Disability Index (HAQ-DI) and C-reactive protein was measured using an immunoturbidometric method. A total of 74 patients were recruited, consisting of 35 rheumatoid arthritis cases and 39 healthy controls. There were no differences between rheumatoid arthritis cases and controls for oxidative stress and antioxidant capacity; however, GSH-Px concentration was markedly elevated in the rheumatoid arthritis sufferers (85.9 ± 147.7 versus 17.3 ± 13.0 mg/L, respectively; mean ± SD; p < 0.01). GSH-Px levels were not associated with severity measured by the HAQ-DI or C-reactive protein. Patients with rheumatoid arthritis demonstrated increased GSH-Px consistent with an adaptive upregulation of GSH-Px to protect against oxidative stress.

  7. 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

  8. Risk factors for classical Kaposi sarcoma in a population-based case-control study in Sicily

    PubMed Central

    Anderson, LA; Lauria, C; Romano, N; Brown, EE; Whitby, D; Graubard, BI; Li, Y; Messina, A; Gafà, L; Vitale, F

    2009-01-01

    Background Classical Kaposi sarcoma (cKS) is a rare complication of Kaposi sarcoma-associated herpes virus (KSHV) infection. We conducted a population-based, frequency-matched case-control study in Sicily to further investigate the reported inverse relationship between smoking and cKS and to identify other factors associated with altered risk. Methods All incident, histologically confirmed, cKS cases in Sicily were eligible. A two-stage cluster sample design was applied to select population controls. KSHV seropositivity was determined using 4 antibody assays (K8.1 and orf73 enzyme immunoassays and 2 immunofluroescence assays). Using SAS-callable SUDAAN we compared the characteristics of cKS cases and KSHV seropositive controls. Odds ratios (ORs) and 95% confidence intervals (CIs) are presented. Results In total, 142 cKS cases and 123 KSHV seropositive controls were recruited. Current cigarette smoking was associated with reduced risk of cKS (OR 0.20, 95% CI 0.06-0.67). Edema was associated with cKS, but only when it presented on the lower extremities (OR 3.65, 95% CI 1.62-8.23). Irrespective of presentation site, diabetes and oral corticosteroid medications were associated with increased risk (ORs, 95% CIs: 4.73, 2.02-11.1 and 2.34, 1.23-4.45, respectively). Never smoking, diabetes and oral corticosteroid medication use were all independently associated with cKS risk. Discussion We confirmed previous reports that cigarette smoking was associated with a reduced risk of cKS, and we found that risk was lowest among current smokers. We also found that cKS risk was strongly and independently associated with oral corticosteroid use and diabetes. Corroboration of these observations and investigation of possible underlying mechanisms are warranted. PMID:19064559

  9. 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.

  10. Insomnia in older adults with chronic obstructive pulmonary disease (COPD) in Hong Kong: a case-control study.

    PubMed

    Xiang, Yu-Tao; Wong, Tak-Shun; Tsoh, Joshua; Ungvari, Gabor S; Correll, Christoph U; Ko, Fanny W S; Hui, David S C; Chiu, Helen F K

    2014-06-01

    This study aimed to determine the frequency and sociodemographic/clinical correlates of insomnia in Chinese patients aged ≥60 years suffering from chronic obstructive pulmonary disease (COPD). In this case-control study of 142 outpatients with COPD and 218 sex- and age-matched control subjects, COPD patients were recruited from a prospective study sample hospitalized in Hong Kong for acute COPD exacerbation (≥2 major COPD symptoms or >1 major+minor COPD symptoms for ≥2 consecutive days). Controls were recruited from social centres in Hong Kong. Activity of daily living was assessed with the Instrumental Activities of Daily Living Scale, life events were evaluated using the Life Event Scale, depressive symptoms were ascertained with the Geriatric Depression Scale, and quality of life was measured using the Medical Outcomes Study Short Form-12. Early, middle and late insomnia were measured using items 4, 5 and 6 of the Hamilton Rating Scale for Depression. The frequency of ≥1 type of insomnia was 47.2% in patients and 25.7% in controls; frequencies of early, middle and late insomnia in patients were 24.6%, 31.0%, and 26.1%, respectively, compared to 14.7%, 14.7% and 11.9% in controls. Group differences were non-significant after controlling for relevant covariates. However, in multiple logistic regression analysis, more physical illnesses (p = 0.02, OR = 1.3, 95% CI = 1.1-1.7) and more severe depressive symptoms (p = 0.009, OR = 1.1, 95% CI = 1.03-1.3) were independently associated with any type of insomnia in COPD patients, accounting for 21.3% of the variance. A significant proportion of older adult Chinese COPD patients suffer from insomnia that warrants more attention in clinical practice.

  11. PAX9 polymorphism and susceptibility to sporadic non-syndromic severe anodontia: a case-control study in southwest China

    PubMed Central

    WANG, Jing; XU, Yuanzhi; CHEN, Jing; WANG, Feiyu; HUANG, Renhuan; WU, Songtao; SHU, Linjing; QIU, Jingyi; YANG, Zhi; XUE, Junjie; WANG, Raorao; ZHAO, Jilin; LAI, Wenli

    2013-01-01

    Our research aimed to look into the clinical traits and genetic mutations in sporadic non-syndromic anodontia and to gain insight into the role of mutations of PAX9, MSX1, AXIN2 and EDA in anodontia phenotypes, especially for the PAX9. Material and Methods: The female proband and her family members from the ethnic Han families underwent complete oral examinations and received a retrospective review. Venous blood samples were obtained to screen variants in the PAX9, MSX1, AXIN2, and EDA genes. A case-control study was performed on 50 subjects with sporadic tooth agenesis (cases) and 100 healthy controls, which genotyped a PAX9 gene polymorphism (rs4904210). Results: Intra-oral and panoramic radiographs revealed that the female proband had anodontia denoted by the complete absence of teeth in both the primary and secondary dentitions, while all her family members maintained normal dentitions. Detected in the female proband were variants of the PAX9 and AXIN2 including A240P (rs4904210) of the PAX9, c.148C>T (rs2240308), c.1365A>G (rs9915936) and c.1386C>T (rs1133683) of the AXIN2. The same variants were present in her unaffected younger brother. The PAX9 variations were in a different state in her parents. Mutations in the MSX1 and EDA genes were not identified. No significant diferences were found in the allele and genotype frequencies of the PAX9 polymorphism between the controls and the subjects with sporadic tooth agenesis. Conclusions: These results suggest that the association of A240P with sporadic tooth agenesis still remains obscure, especially for different populations. The genotype/phenotype correlation in congenital anodontia should be verified. PMID:23857653

  12. 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.

  13. 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

  14. Plasma biomarkers of risk for death in a multicenter phase 3 trial with uniform transplant characteristics post–allogeneic HCT

    PubMed Central

    Abu Zaid, Mohammad; Wu, Juan; Wu, Cindy; Logan, Brent R.; Yu, Jeffrey; Cutler, Corey; Antin, Joseph H.; Paczesny, Sophie

    2017-01-01

    A phase 3 clinical trial (BMT CTN 0402) comparing tacrolimus/sirolimus (Tac/Sir) vs tacrolimus/methotrexate (Tac/Mtx) as graft-versus-host disease (GVHD) prophylaxis after matched-related allogeneic hematopoietic cell transplantation (HCT) recently showed no difference between study arms in acute GVHD-free survival. Within this setting of a prospective, multicenter study with uniform GVHD prophylaxis, conditioning regimen, and donor source, we explored the correlation of 10 previously identified biomarkers with clinical outcomes after allogeneic HCT. We measured biomarkers from plasma samples collected in 211 patients using enzyme-linked immunosorbent assay (Tac/Sir = 104, Tac/Mtx = 107). High suppression of tumorigenicity-2 (ST2) and T-cell immunoglobulin mucin-3 (TIM3) at day 28 correlated with 2-year nonrelapse mortality in multivariate analysis (P = .0050, P = .0075, respectively) and in a proportional hazards model with time-dependent covariates (adjusted hazard ratio: 2.43 [1.49–3.95], P = .0038 and 4.87 [2.53–9.34], P < .0001, respectively). High ST2 and TIM3 correlated with overall survival. Chemokine (C-X-C motif) ligand 9 (CXCL9) levels above the median were associated with chronic GVHD compared with levels below the median in a time-dependent proportional hazard analysis (P = .0069). Low L-Ficolin was associated with hepatic veno-occlusive disease (P = .0053, AUC = 0.80). We confirmed the correlation of plasma-derived proteins, previously assessed in single-center cohorts, with clinical outcomes after allogeneic HCT within this prospective, multicenter study. PMID:27827824

  15. Coordination and management of multicenter clinical studies in trauma: Experience from the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) Study

    PubMed Central

    Rahbar, Mohammad H.; Fox, Erin E.; del Junco, Deborah J.; Cotton, Bryan A.; Podbielski, Jeanette M.; Matijevic, Nena; Cohen, Mitchell J.; Schreiber, Martin A.; Zhang, Jiajie; Mirhaji, Parsa; Duran, Sarah; Reynolds, Robert J.; Benjamin-Garner, Ruby; Holcomb, John B.

    2011-01-01

    Aim Early death due to hemorrhage is a major consequence of traumatic injury. Transfusion practices differ among hospitals and it is unknown which transfusion practices improve survival. This report describes the experience of the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) Study Data Coordination Center in designing and coordinating a study to examine transfusion practices at ten Level 1 trauma centers in the U.S. Methods PROMMTT was a multisite prospective observational study of severely injured transfused trauma patients. The clinical sites collected real-time information on the timing and amounts of blood product infusions as well as colloids and crystalloids, vital signs, initial diagnostic and clinical laboratory tests, life saving interventions and other clinical care data. Results Between July 2009 and October 2010, PROMMTT screened 12,561 trauma admissions and enrolled 1,245 patients who received one or more blood transfusions within 6 hours of ED admission. A total of 297 massive transfusions were observed over the course of the study at a combined rate of 5.0 massive transfusion patients/week. Conclusion PROMMTT is the first multisite study to collect real-time prospective data on trauma patients requiring transfusion. Support from the Department of Defense and collaborative expertise from the ten participating centers helped to demonstrate the feasibility of prospective trauma transfusion studies. The observational data collected from this study will be an invaluable resource for research in trauma surgery and it will guide the design and conduct of future randomized trials. PMID:22001613

  16. Research priorities for a multi-center child abuse pediatrics network - CAPNET.

    PubMed

    Lindberg, Daniel M; Wood, Joanne N; Campbell, Kristine A; Scribano, Philip V; Laskey, Antoinette; Leventhal, John M; Pierce, Mary Clyde; Runyan, Desmond K

    2017-03-01

    Although child maltreatment medical research has benefited from several multi-center studies, the new specialty of child abuse pediatrics has not had a sustainable network capable of pursuing multiple, prospective, clinically-oriented studies. The Child Abuse Pediatrics Network (CAPNET) is a new multi-center research network dedicated to child maltreatment medical research. In order to establish a relevant, practical research agenda, we conducted a modified Delphi process to determine the topic areas with highest priority for such a network. Research questions were solicited from members of the Ray E. Helfer Society and study authors and were sorted into topic areas. These topic areas were rated for priority using iterative rounds of ratings and in-person meetings. The topics rated with the highest priority were missed diagnosis and selected/indicated prevention. This agenda can be used to target future multi-center child maltreatment medical research.

  17. 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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    1999-01-01

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

  20. Validation of a real-time PCR based method for detection of Clostridium botulinum types C, D and their mosaic variants C-D and D-C in a multicenter collaborative trial.

    PubMed

    Woudstra, Cedric; Skarin, Hanna; Anniballi, Fabrizio; Auricchio, Bruna; De Medici, Dario; Bano, Luca; Drigo, Ilenia; Hansen, Trine; Löfström, Charlotta; Hamidjaja, Raditijo; van Rotterdam, Bart J; Koene, Miriam; Bäyon-Auboyer, Marie-Hélène; Buffereau, Jean-Philippe; Fach, Patrick

    2013-08-01

    Two real-time PCR arrays based on the GeneDisc(®) cycler platform (Pall-GeneDisc Technologies) were evaluated in a multicenter collaborative trial for their capacity to specifically detect and discriminate Clostridium botulinum types C, D and their mosaic variants C-D and D-C that are associated with avian and mammalian botulism. The GeneDisc(®) arrays developed as part of the DG Home funded European project 'AnibioThreat' were highly sensitive and specific when tested on pure isolates and naturally contaminated samples (mostly clinical specimen from avian origin). Results of the multicenter collaborative trial involving eight laboratories in five European Countries (two laboratories in France, Italy and The Netherlands, one laboratory in Denmark and Sweden), using DNA extracts issued from 33 pure isolates and 48 naturally contaminated samples associated with animal botulism cases, demonstrated the robustness of these tests. Results showed a concordance among the eight laboratories of 99.4%-100% for both arrays. The reproducibility of the tests was high with a relative standard deviation ranging from 1.1% to 7.1%. Considering the high level of agreement achieved between the laboratories these PCR arrays constitute robust and suitable tools for rapid detection of C. botulinum types C, D and mosaic types C-D and D-C. These are the first tests for C. botulinum C and D that have been evaluated in a European multicenter collaborative trial.

  1. 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

  2. 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.

  3. Influenza vaccination coverage among medical residents: an Italian multicenter survey.

    PubMed

    Costantino, Claudio; Mazzucco, Walter; Azzolini, Elena; Baldini, Cesare; Bergomi, Margherita; Biafiore, Alessio Daniele; Bianco, Manuela; Borsari, Lucia; Cacciari, Paolo; Cadeddu, Chiara; Camia, Paola; Carluccio, Eugenia; Conti, Andrea; De Waure, Chiara; Di Gregori, Valentina; Fabiani, Leila; Fallico, Roberto; Filisetti, Barbara; Flacco, Maria E; Franco, Elisabetta; Furnari, Roberto; Galis, Veronica; Gallea, Maria R; Gallone, Maria F; Gallone, Serena; Gelatti, Umberto; Gilardi, Francesco; Giuliani, Anna R; Grillo, Orazio C; Lanati, Niccolò; Mascaretti, Silvia; Mattei, Antonella; Micò, Rocco; Morciano, Laura; Nante, Nicola; Napoli, Giuseppe; Nobile, Carmelo Giuseppe; Palladino, Raffaele; Parisi, Salvatore; Passaro, Maria; Pelissero, Gabriele; Quarto, Michele; Ricciardi, Walter; Romano, Gabriele; Rustico, Ennio; Saponari, Anita; Schioppa, Francesco S; Signorelli, Carlo; Siliquini, Roberta; Trabacchi, Valeria; Triassi, Maria; Varetta, Alessia; Ziglio, Andrea; Zoccali, Angela; Vitale, Francesco; Amodio, Emanuele

    2014-01-01

    Although influenza vaccination is recognized to be safe and effective, recent studies have confirmed that immunization coverage among health care workers remain generally low, especially among medical residents (MRs). Aim of the present multicenter study was to investigate attitudes and determinants associated with acceptance of influenza vaccination among Italian MRs. A survey was performed in 2012 on MRs attending post-graduate schools of 18 Italian Universities. Each participant was interviewed via an anonymous, self-administered, web-based questionnaire including questions on attitudes regarding influenza vaccination. A total of 2506 MRs were recruited in the survey and 299 (11.9%) of these stated they had accepted influenza vaccination in 2011-2012 season. Vaccinated MRs were older (P = 0.006), working in clinical settings (P = 0.048), and vaccinated in the 2 previous seasons (P<0.001 in both seasons). Moreover, MRs who had recommended influenza vaccination to their patients were significantly more compliant with influenza vaccination uptake in 2011-2012 season (P<0.001). "To avoid spreading influenza among patients" was recognized as the main reason for accepting vaccination by less than 15% of vaccinated MRs. Italian MRs seem to have a very low compliance with influenza vaccination and they seem to accept influenza vaccination as a habit that is unrelated to professional and ethical responsibility. Otherwise, residents who refuse vaccination in the previous seasons usually maintain their behaviors. Promoting correct attitudes and good practice in order to improve the influenza immunization rates of MRs could represent a decisive goal for increasing immunization coverage among health care workers of the future.

  4. Neurophysiology versus clinical genetics in Rett syndrome: A multicenter study

    PubMed Central

    Halbach, Nicky; 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

    2016-01-01

    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 The Authors. American Journal of Medical Genetics Part A published by Wiley Periodicals, Inc. PMID:27354166

  5. Reducing between scanner differences in multi-center PET studies.

    PubMed

    Joshi, Aniket; Koeppe, Robert A; Fessler, Jeffrey A

    2009-05-15

    This work is part of the multi-center Alzheimer's Disease Neuroimaging Initiative (ADNI), a large multi-site study of dementia, including patients having mild cognitive impairment (MCI), probable Alzheimer's disease (AD), as well as healthy elderly controls. A major portion of ADNI involves the use of [(18)F]-fluorodeoxyglucose (FDG) with positron emission tomography (PET). The objective of this paper is the reduction of inter-scanner differences in the FDG-PET scans obtained from the 50 participating PET centers having fifteen different scanner models. In spite of a standardized imaging protocol, systematic inter-scanner variability in PET images from various sites is observed primarily due to differences in scanner resolution, reconstruction techniques, and different implementations of scatter and attenuation corrections. Two correction steps were developed by comparison of 3-D Hoffman brain phantom scans with the 'gold standard' digital 3-D Hoffman brain phantom: i) high frequency correction; where a smoothing kernel for each scanner model was estimated to smooth all images to a common resolution and ii) low frequency correction; where smooth affine correction factors were obtained to reduce the attenuation and scatter correction errors. For the phantom data, the high frequency correction reduced the variability by 20%-50% and the low frequency correction further reduced the differences by another 20%-25%. Correction factors obtained from phantom studies were applied to 95 scans from normal control subjects obtained from the participating sites. The high frequency correction reduced differences similar to the phantom studies. However, the low frequency correction did not further reduce differences; hence further refinement of the procedure is necessary.

  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. Association between signs and symptoms of temporomandibular disorders and pregnancy (case control study).

    PubMed

    Mayoral, Verónica A; Espinosa, Irene A; Montiel, Alvaro J

    2013-01-01

    Temporomandibular disorders (TMD) are a combination of multifactoral etiological muscular-skeletal symptoms. Prevalence is greater in women, where sexual hormones are important in pathogenesis, and its behavior at different stages of the reproductive life of women has never been fully documented. The general objective was to determine the association between signs and symptoms of temporomandibular disorders and pregnancy. A case-control study was conducted on 66 pregnant patients who met with a medical specialist and 66 non-pregnant women paired by age, who visited the General Regional Hospital 36 of Mexico's Social Security Institute (IMSS). These patients were examined for the Temporomandibular (TMD) research project to establish the prevalence of TMD in both groups. Descriptive variables were calculated through him SPSS 17 program and the association between groups with Xi Square and Ratio Possibilities (OR), The average age was 28.23 +/- 5.9 years in both groups, with median gestation 32.97 weeks. Most of the participants had a domestic partner. The prevalence of TDM in the non-pregnant group was 45.5% and only 15.2% in the pregnant group (chi2 = 14.34, p < .000). We calculated the ratio of possibilities (RP) pregnant/non-pregnant with a value of 41 with confidence intervals from 23 to 72. In conclusion, pregnancy protects women from TDM signs and symptoms. Pregnant women have a considerably lower prevalence of these disorders.

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

    PubMed

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

    2002-08-01

    This case-control study was designed to test the hypothesis that the risk of breast cancer varies by type and colour of the hair colouring products used. A total of 608 cases and 609 controls were included in the study. We found no increased risk associated with the overall use of hair dye products or exclusive use of permanent or temporary types of hair dye products. Among those who reported to have exclusively used semi-permanent types of hair colouring products, some of the ORs were elevated. However, none of the ORs related to age at first use, duration of use, total number of applications, and years since first use, was statistically significant. There was also no increased risk of breast cancer associated with exclusive use of dark or light hair colouring products, or use of mixed types or colours of hair dye products. We also found no increased risk of breast cancer associated with hair dye use based on an individual's reason for using a hair colouring product, such as to cover grey or to change natural hair colour. These data suggest that the use of hair colouring produc