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Sample records for multicenter case-control samples

  1. Predictors of wound infection in elective colorectal surgery. Multicenter observational case-control study.

    PubMed

    Fraccalvieri, Doménico; Kreisler Moreno, Esther; Flor Lorente, Blas; Torres García, Antonio; Muñoz Calero, Alberto; Mateo Vallejo, Francisco; Biondo, Sebastiano

    2014-01-01

    The aim of this study is to evaluate the usefulness of Vicryl Plus(®) suture in reducing the rate of postoperative wound infection in elective colorectal surgery. A prospective case-control multicenter study with 480 patients undergoing elective colorectal surgery was performed between 2006 and 2007. Patients were divided in 2 groups of equal sample size: group 1, closure of the abdominal wall using Vicryl Plus(®) and group 2 where PDS II(®) was used. The study involved 5 hospitals in the Spanish State. Wound infection was classified into superficial and deep. All patients diagnosed of wound infection during the hospital stay and up to 30 days after discharge were studied. For the statistical analysis Chi-square test and Fisher exact were used for bivariate analysis and logistic regression model for multivariate analysis. Wound infection rates were significantly lower in group 1: 14.6 vs. 29.2. Multivariate analysis showed that risk of wound infection was higher in patients with cancer, lung disease, anemia, operative time greater than 2 h, lack of second dose intra-operative prophylactic antibiotic and laparotomy closure with PDS suture II(®). The use of suture coated with triclosan can be an effective prophylactic tool in reducing wound infection rate in patients undergoing elective colorectal surgery. Copyright © 2013 AEC. Published by Elsevier Espana. All rights reserved.

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

    PubMed Central

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

    1984-01-01

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

  3. Risk Factors for Contact Lens-Related Microbial Keratitis: A Case-Control Multicenter Study.

    PubMed

    Sauer, Arnaud; Meyer, Nicolas; Bourcier, Tristan

    2016-05-01

    The most feared complication of contact lens (CL) wear is microbial keratitis (MK), even though its incidence remains low. This study aimed to identify the risk factors of CL-related MK in a large, prospective, multicenter case-control study. A multicenter case-control study was designed. The CL-related MK subpopulation (Case) was compared with healthy CL wearers (Control) using a 52-item anonymous questionnaire designed to determine subject demographics and lens wear history. Univariate and multivariate logistic regression analyses were performed to compare both groups. The study enrolled 499 cases and 508 controls. The risk factors associated with the greatest increased odds of CL-related MK were as follows: using disinfecting solution more than 3 months (odds ratio [OR]=1.94), cosmetic CL wear and use of multipurpose disinfection solution (1.37 each), overnight wear, and soft lens use (OR=1.24 each). The protective factors associated with the greatest reduction in OR were fitting by an ophthalmologist (OR=0.73) and hyperopia versus myopia (OR=0.75). The infectious determinants were linked to the type of lenses, hygiene routine, CL handling, disinfecting solution, and storage case. This study aimed to highlight the increasingly CL-related MK, which likely occurs because of lack of patient information regarding basic rules of hygiene and CL care and handling.

  4. [Risk factors for contact lens-related microbial keratitis: A multicenter case-control study].

    PubMed

    Becmeur, P H; Abry, F; Bourcier, T; Meyer, N; Sauer, A

    2017-03-01

    Currently, the most feared complication by ophthalmologists of contact lens (CL) wear is microbial keratitis (MK), even though its incidence remains low. It is also a significant financial burden for society. This study aimed to identify the risk factors for CL-related MK especially with regard to hygiene and pattern of use, in a large, prospective, multicenter, case-control study. A multicenter retrospective case-control study was designed. The CL-related MK subpopulation (case) was compared with healthy CL wearers (control) using a 52-item anonymous questionnaire designed to determine subject demographics, lens wear history, lens type and disinfection solution, fitting, patient education, hygiene and maintenance of contact lenses, and patient history. Univariate logistic regression analysis was performed to compare both groups. The study included 497 cases and 364 controls. The risk factors associated with the greatest increased odds of CL-related MK were as follows: extended wear (OR=2.96 [1.65-5.33], P<0.001), occasional overnight lens use (OR=6.37 [4,55-8.90], P<0.001), fitting by an optician (OR=1.97 [1.38-2.83], P<0.001), absence of ophthalmologic exam (OR=6.56 [2-22], P<0.01) or no training in handling the contact lens (OR=4.47 [2.27-8.77], P<0.01), use of optician's disinfection solution (OR=5.55 [3.12-9.85], P<0.001), mixing solutions ("topping off") (OR=4.68 [2.73-8.04], P<0.001), no case replacement (OR=3.95 [2.28-6.82] P<0.01), no compliance with hygiene rules and smoking (OR=2.29 [1.67-3.14], P<0.01). The protective factors associated with the greatest reduction in OR were female gender (OR=0.49 [0.36-0.66], P<0.01), hypermetropia (OR=0.28 [0.16-0.48], P=0.01), rigid contact lens wear, fitting by an ophthalmologist, written and verbal instruction, and daily case maintenance. The knowledge of these risks factors incentivizes action at all levels to reduce the incidence of MK, from the prescriber to the patient, including the type of CL, case and

  5. 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

  6. Occupation and risk of parkinsonism: a multicenter case-control study.

    PubMed

    Tanner, Caroline M; Ross, G Webster; Jewell, Sarah A; Hauser, Robert A; Jankovic, Joseph; Factor, Stewart A; Bressman, Susan; Deligtisch, Amanda; Marras, Connie; Lyons, Kelly E; Bhudhikanok, Grace S; Roucoux, Diana F; Meng, Cheryl; Abbott, Robert D; Langston, J William

    2009-09-01

    We examined risk of parkinsonism in occupations (agriculture, education, health care, welding, and mining) and toxicant exposures (solvents and pesticides) putatively associated with parkinsonism. To investigate occupations, specific job tasks, or exposures and risk of parkinsonism and clinical subtypes. Case-control. Eight movement disorders centers in North America. Inclusion criteria were parkinsonism (>or=2 cardinal signs), diagnosis within 8 years of recruitment (to minimize survival bias), and ability to participate in detailed telephone interviews. Control subjects were primarily nonblood relatives or acquaintances of patients. This multicenter case-control study compared lifelong occupational and job task histories to determine associations with parkinsonism and certain clinical subtypes (postural instability and gait difficulty and age at diagnosis

  7. Past medical history and pancreatic cancer risk: Results from a multicenter case-control study.

    PubMed

    Maisonneuve, Patrick; Lowenfels, Albert B; Bueno-de-Mesquita, H Bas; Ghadirian, Parviz; Baghurst, Peter A; Zatonski, Witold A; Miller, Anthony B; Duell, Eric J; Boffetta, Paolo; Boyle, Peter

    2010-02-01

    To investigate risk factors that may be linked to pancreatic cancer. We designed a multicenter population-based case-control (823 cases, 1679 control patients) study with data collection by using a common protocol and questionnaire. Participating centers were located in Australia, Canada, the Netherlands, and Poland. After adjustment for confounding factors, a positive history of pancreatitis was associated with pancreatic cancer (odds ratio [OR], 4.68; 95% confidence interval [95% CI], 2.23-9.84). The risk was especially high in heavy smokers (OR, 15.4; 95% CI, 3.18-74.9). Patients with diabetes had an increased risk of developing pancreatic cancer (OR, 2.16; 95% CI, 1.60-2.91). The risk was highest in the first year after the development of diabetes (OR, 6.68; 95% CI, 3.56-12.6) and decreased over time. A history of allergy was associated with a reduced risk of pancreas cancer (OR, 0.64; 95% CI, 0.50-0.82). Patients with newly diagnosed diabetes and patients with pancreatitis, particularly in heavy smokers, have an increased risk for developing pancreatic cancer. In addition to being risk factors, these conditions could be early manifestations of underlying pancreatic cancer. A history of allergy decreases the risk of pancreatic cancer. 2010 Elsevier Inc. All rights reserved.

  8. 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.

  9. Multicenter case-control study protocol of pneumonia etiology in children: Global Approach to Biological Research, Infectious diseases and Epidemics in Low-income countries (GABRIEL network).

    PubMed

    Picot, Valentina Sanchez; Bénet, Thomas; Messaoudi, Melina; Telles, Jean-Noël; Chou, Monidarin; Eap, Tekchheng; Wang, Jianwei; Shen, Kunling; Pape, Jean-William; Rouzier, Vanessa; Awasthi, Shally; Pandey, Nitin; Bavdekar, Ashish; Sanghvi, Sonali; Robinson, Annick; Contamin, Bénédicte; Hoffmann, Jonathan; Sylla, Maryam; Diallo, Souleymane; Nymadawa, Pagbajabyn; Dash-Yandag, Budragchaagiin; Russomando, Graciela; Basualdo, Wilma; Siqueira, Marilda M; Barreto, Patricia; Komurian-Pradel, Florence; Vernet, Guy; Endtz, Hubert; Vanhems, Philippe; Paranhos-Baccalà, Gláucia

    2014-12-10

    Data on the etiologies of pneumonia among children are inadequate, especially in developing countries. The principal objective is to undertake a multicenter incident case-control study of <5-year-old children hospitalized with pneumonia in developing and emerging countries, aiming to identify the causative agents involved in pneumonia while assessing individual and microbial factors associated with the risk of severe pneumonia. A multicenter case-control study, based on the GABRIEL network, is ongoing. Ten study sites are located in 9 countries over 3 continents: Brazil, Cambodia, China, Haiti, India, Madagascar, Mali, Mongolia, and Paraguay. At least 1,000 incident cases and 1,000 controls will be enrolled and matched for age and date. Cases are hospitalized children <5 years with radiologically confirmed pneumonia, and the controls are children without any features suggestive of pneumonia. Respiratory specimens are collected from all enrolled subjects to identify 19 viruses and 5 bacteria. Whole blood from pneumonia cases is being tested for 3 major bacteria. S. pneumoniae-positive specimens are serotyped. Urine samples from cases only are tested for detection of antimicrobial activity. The association between procalcitonin, C-reactive protein and pathogens is being evaluated. A discovery platform will enable pathogen identification in undiagnosed samples. This multicenter study will provide descriptive results for better understanding of pathogens responsible for pneumonia among children in developing countries. The identification of determinants related to microorganisms associated with pneumonia and its severity should facilitate treatment and prevention.

  10. Multicenter case-control study on restless legs syndrome in multiple sclerosis: the REMS study.

    PubMed

    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; Lo Fermo, Salvatore; Ubiali, Emilio; Viscardi, Massimo; Rottoli, Mariarosa; Nobili, Lino; Protti, Alessandra; Ferrillo, Franco; Allena, Marta; Mancardi, Gianluigi; Guarnieri, Biancamaria; Londrillo, Francesco

    2008-07-01

    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. Prospective, multicenter, case-control epidemiologic survey. Twenty sleep centers certified by the Italian Association of Sleep Medicine. Eight hundred and sixty-one patients affected by MS and 649 control subjects. N/A. 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. 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.

  11. Macrophage activation syndrome in systemic lupus erythematosus: a multicenter, case-control study in China.

    PubMed

    Liu, Ai-Chun; Yang, Yue; Li, Meng-Tao; Jia, Yuan; Chen, Sheng; Ye, Shuang; Zeng, Xiang-Zong; Wang, Zhao; Zhao, Jin-Xia; Liu, Xiang-Yuan; Zhu, Jian; Zhao, Yan; Zeng, Xiao-Feng; Li, Zhan-Guo

    2017-04-13

    The objective of this study was to describe the clinical and laboratory characteristics, precipitating factors, treatment, and outcome of macrophage activation syndrome (MAS) complicating systemic lupus erythematosus (SLE). A multicenter case-control study was performed across six tertiary hospitals from 1997 to 2014. A total of 32 patients with SLE-associated MAS were enrolled. Sixty-four age- and sex-matched SLE patients diagnosed in the same period without MAS episodes were selected as controls. The most frequent clinical feature was fever, followed by splenomegaly. Hyperferritinemia, hypoalbuminemia, and hyper-lactate dehydrogenase (LDH)-nemia were among the most common laboratory abnormalities. Compared with pre-MAS visit, patients at the onset of MAS had greater frequencies of renal involvement, liver dysfunction, and cytopenia. Receiver operating characteristic (ROC) analysis identified optimal cutoff values of ferritin (>662.5 ng/mL) and LDH (>359 U/mL) to predict the occurrence of MAS in SLE. SLE flare and infection were the common triggers of MAS in SLE. Abortion and parturition were recorded as well. The overall mortality rate was 12.5%. All patients received corticosteroids. Cyclosporine A, cyclophosphamide, and etoposide were the three most commonly used immunosuppressants. Rituximab was given to one patient. Intravenous immunoglobulin (IVIG) was added for 46.9% patients. MAS is a potentially fatal complication of SLE. Its occurrence is most frequently associated with active SLE disease or infection. The presentation of unexplained fever, cytopenia, or liver dysfunction, with high levels of ferritin and LDH, in patients with SLE should raise the suspicion of MAS. Corticosteroids with immunosuppressants and IVIG may be an appropriate treatment.

  12. Diet and risk of adult leukemia: a multicenter case-control study in China.

    PubMed

    Liu, Ping; Holman, C D'Arcy J; Jin, Jie; Zhang, Min

    2015-08-01

    Epidemiologic studies on diet and leukemia risk have shown inconsistent results. This study examined the associations between dietary factors and the risk of adult leukemia in Chinese populations. A multicenter case-control study was conducted in southeast and northeast China between 2008 and 2013. It included 442 incident cases with hematologically confirmed leukemia and 442 controls, individually match to cases by gender, birth quinquennium, and study site. Information on diet was sought from face-to-face interviews using a validated and reliable 103-item food frequency questionnaire. Odds ratios (ORs) and confidence intervals (CIs) were estimated by conditional logistic regression. Vegetables intake was associated with decreased risk of adult leukemia, with a significant dose-response relationship and adjusted OR of 0.30 (95 % CI 0.18-0.50) for the highest versus the lowest quartiles intake. Compared with non-consumers, the adjusted OR was 0.51 (95 % CI 0.29-0.93) for those who consumed milk at the highest tertile. Intakes of fruits, red meat, poultry, and fish were not associated with the risk. Dietary nutrients, including dietary fiber, carotenoids, vitamins B1, B2, and C, niacin, and folate, were significantly associated with reduced risks. Elevated risk was related to dietary intake animal fat and dietary habits with frequent intakes of fat, deep-fried, and smoked foods ( p for trend <0.05). Our findings suggest that diets rich in vegetables and adequate amount of milk reduce the risk of adult leukemia, whereas diets preferring fat, deep-fried, and smoked foods increase the risk in Chinese populations.

  13. Mobile phone use and brain tumors in children and adolescents: a multicenter case-control study.

    PubMed

    Aydin, Denis; Feychting, Maria; Schüz, Joachim; Tynes, Tore; Andersen, Tina Veje; Schmidt, Lisbeth Samsø; Poulsen, Aslak Harbo; Johansen, Christoffer; Prochazka, Michaela; Lannering, Birgitta; Klæboe, Lars; Eggen, Tone; Jenni, Daniela; Grotzer, Michael; Von der Weid, Nicolas; Kuehni, Claudia E; Röösli, Martin

    2011-08-17

    It has been hypothesized that children and adolescents might be more vulnerable to possible health effects from mobile phone exposure than adults. We investigated whether mobile phone use is associated with brain tumor risk among children and adolescents. CEFALO is a multicenter case-control study conducted in Denmark, Sweden, Norway, and Switzerland that includes all children and adolescents aged 7-19 years who were diagnosed with a brain tumor between 2004 and 2008. We conducted interviews, in person, with 352 case patients (participation rate: 83%) and 646 control subjects (participation rate: 71%) and their parents. Control subjects were randomly selected from population registries and matched by age, sex, and geographical region. We asked about mobile phone use and included mobile phone operator records when available. Odds ratios (ORs) for brain tumor risk and 95% confidence intervals (CIs) were calculated using conditional logistic regression models. Regular users of mobile phones were not statistically significantly more likely to have been diagnosed with brain tumors compared with nonusers (OR = 1.36; 95% CI = 0.92 to 2.02). Children who started to use mobile phones at least 5 years ago were not at increased risk compared with those who had never regularly used mobile phones (OR = 1.26, 95% CI = 0.70 to 2.28). In a subset of study participants for whom operator recorded data were available, brain tumor risk was related to the time elapsed since the mobile phone subscription was started but not to amount of use. No increased risk of brain tumors was observed for brain areas receiving the highest amount of exposure. The absence of an exposure-response relationship either in terms of the amount of mobile phone use or by localization of the brain tumor argues against a causal association.

  14. Risk and protective factors for falls from furniture in young children: multicenter case-control study.

    PubMed

    Kendrick, Denise; Maula, Asiya; Reading, Richard; Hindmarch, Paul; Coupland, Carol; Watson, Michael; Hayes, Mike; Deave, Toity

    2015-02-01

    Falls from furniture are common in young children but there is little evidence on protective factors for these falls. To estimate associations for risk and protective factors for falls from furniture in children aged 0 to 4 years. Multicenter case-control study at hospitals, minor injury units, and general practices in and around 4 UK study centers. Recruitment commenced June 14, 2010, and ended April 27, 2012. Participants included 672 children with falls from furniture and 2648 control participants matched on age, sex, calendar time, and study center. Thirty-five percent of cases and 33% of control individuals agreed to participate. The mean age was 1.74 years for cases and 1.91 years for control participants. Fifty-four percent of cases and 56% of control participants were male. Exposures included safety practices, safety equipment use, and home hazards. Falls from furniture occurring at the child's home resulting in attendance at an emergency department, minor injury unit, or hospital admission. Compared with parents of control participants, parents of cases were significantly more likely not to use safety gates in the home (adjusted odds ratio [AOR], 1.65; 95% CI, 1.29-2.12) and not to have taught their children rules about climbing on kitchen objects (AOR, 1.58; 95% CI, 1.16-2.15). Cases aged 0 to 12 months were significantly more likely to have been left on raised surfaces (AOR, 5.62; 95% CI, 3.62-8.72), had their diapers changed on raised surfaces (AOR, 1.89; 95% CI, 1.24-2.88), and been put in car/bouncing seats on raised surfaces (AOR, 2.05; 95% CI, 1.29-3.27). Cases 3 years and older were significantly more likely to have played or climbed on furniture (AOR, 9.25; 95% CI, 1.22-70.07). Cases were significantly less likely to have played or climbed on garden furniture (AOR, 0.74; 95% CI, 0.56-0.97). If estimated associations are causal, some falls from furniture may be prevented by incorporating advice into child health contacts, personal child health

  15. Risk factors for operated carpal tunnel syndrome: a multicenter population-based case-control study

    PubMed Central

    Mattioli, Stefano; Baldasseroni, Alberto; Bovenzi, Massimo; Curti, Stefania; Cooke, Robin MT; Campo, Giuseppe; Barbieri, Pietro G; Ghersi, Rinaldo; Broccoli, Marco; Cancellieri, Maria Pia; Colao, Anna Maria; dell'Omo, Marco; Fateh-Moghadam, Pirous; Franceschini, Flavia; Fucksia, Serenella; Galli, Paolo; Gobba, Fabriziomaria; Lucchini, Roberto; Mandes, Anna; Marras, Teresa; Sgarrella, Carla; Borghesi, Stefano; Fierro, Mauro; Zanardi, Francesca; Mancini, Gianpiero; Violante, Francesco S

    2009-01-01

    Background Carpal tunnel syndrome (CTS) is a socially and economically relevant disease caused by compression or entrapment of the median nerve within the carpal tunnel. This population-based case-control study aims to investigate occupational/non-occupational risk factors for surgically treated CTS. Methods Cases (n = 220) aged 18-65 years were randomly drawn from 13 administrative databases of citizens who were surgically treated with carpal tunnel release during 2001. Controls (n = 356) were randomly sampled from National Health Service registry records and were frequency matched by age-gender-specific CTS hospitalization rates. Results At multivariate analysis, risk factors were blue-collar/housewife status, BMI ≥ 30 kg/m2, sibling history of CTS and coexistence of trigger finger. Being relatively tall (cut-offs based on tertiles: women ≥165 cm; men ≥175 cm) was associated with lower risk. Blue-collar work was a moderate/strong risk factor in both sexes. Raised risks were apparent for combinations of biomechanical risk factors that included frequent repetitivity and sustained force. Conclusion This study strongly underlines the relevance of biomechanical exposures in both non-industrial and industrial work as risk factors for surgically treated CTS. PMID:19758429

  16. 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.

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

    PubMed

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

    2016-01-01

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

  18. A multicenter case-control study of risk factors for equine protozoal myeloencephalitis.

    PubMed

    Cohen, Noah D; Mackay, Robert J; Toby, Ellen; Andrews, Frank M; Barr, Bonnie S; Beech, Jill; Bernard, William V; Clark, Carol K; Divers, Thomas J; Furr, Martin O; Kohn, Catherine W; Levy, Michel; Reed, Stephen M; Seahorn, Thomas L; Slovis, Nathan M

    2007-12-15

    To identify risk factors for equine protozoal myeloencephalitis (EPM) among horses examined at 11 equine referral hospitals. Case-control study. 183 horses with EPM, 297 horses with neurologic disease other than EPM (neurologic controls), and 168 horses with non-neurologic diseases (non-neurologic controls) examined at 11 equine referral hospitals in the United States. A study data form was completed for all horses. Data were compared between the case group and each of the control groups by means of bivariate and multivariate polytomous logistic regression. Relative to neurologic control horses, case horses were more likely to be > or = 2 years old and to have a history of cats residing on the premises. Relative to non-neurologic control horses, case horses were more likely to be used for racing or Western performance. Results indicated that cats may play a role in the natural epidemiology of EPM, that the disease is less common among horses < 2 years of age relative to other neurologic diseases, and that horses used for particular types of competition may have an increased risk of developing EPM.

  19. 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

  20. Urinary bladder cancer risk factors in Egypt: a multi-center case-control study

    PubMed Central

    Zheng, Yun-Ling; Amr, Sania; Saleh, Doa’a A.; Dash, Chiranjeev; Ezzat, Sameera; Mikhail, Nabiel N.; Gouda, Iman; Loay, Iman; Hifnawy, Tamer; Abdel-Hamid, Mohamed; Khaled, Hussein; Wolpert, Beverly; Abdel-Aziz, Mohamed A.; Loffredo, Christopher A.

    2011-01-01

    Background We investigated associations between tobacco exposure, history of schistosomiasis and bladder cancer risk in Egypt. Methods We analyzed data from a case-control study (1,886 newly diagnosed and histologically confirmed cases and 2,716 age-, gender-, and residence-matched, population-based controls). Using logistic regression we estimated the covariate-adjusted odds ratios (OR) and 95% confidence interval (CI) of the associations. Results Among men, cigarette smoking was associated with an increased risk of urothelial carcinoma (UC) (OR = 1.8, 95% CI = 1.4, 2.2), but not squamous cell carcinoma (SCC); smoking both waterpipes and cigarettes was associated with an even greater risk for UC (OR = 2.9, 95% CI = 2.1, 3.9) and a statistically significant risk for SCC (OR = 1.8, 95% CI = 1.2, 2.6). Among non-smoking men and women, to environmental tobacco smoke exposure was associated with an increased risk of UC. History of schistosomiasis was associated with increased risk of both UC (OR = 1.9, 95% CI = 1.2, 2.9) and SCC (OR = 1.9, 95% CI = 1.2, 3.0) in women and to a lesser extent (OR = 1.4, 95% CI = 1.2, 1.7 and OR = 1.4, 95% CI = 1.1, 1.7, for UC and SCC respectively) in men. Conclusions The results suggest that schistosomiasis and tobacco smoking increase the risk of both SCC and UC. Impact This study provides new evidence for associations between bladder cancer subtypes and schistosomiasis, and suggests that smoking both cigarettes and waterpipes increases the risk for SCC and UC in Egyptian men. PMID:22147365

  1. Meat consumption, genetic susceptibility, and colon cancer risk: a United States multicenter case-control study.

    PubMed

    Kampman, E; Slattery, M L; Bigler, J; Leppert, M; Samowitz, W; Caan, B J; Potter, J D

    1999-01-01

    Meat consumption may especially increase risk of colon cancer when the meat is prepared at high temperatures and consumed by subjects with an inherited susceptibility to well-done meat. In this United States case-control study, the association between meat consumption, genetic susceptibility, and colon cancer risk was studied. Meat consumption data were available from a detailed diet history questionnaire and from questions about methods of preparation. Molecular variants in the carcinogen-metabolizing genes NAT2 and GSTM1 were determined in DNA extracted from WBCs. A total of 1542 cases and 1860 population-based controls were included in these analyses. The amount of red and white meat consumed was not associated with overall colon cancer risk. Processed meat consumption was weakly positively associated with colon cancer risk in men only (odds ratio for highest versus lowest quintile of intake = 1.4, 95% confidence interval = 1.0-1.9). The frequency of fried, broiled, baked, or barbecued meat, use of drippings, and doneness of meat were not significantly associated with risk. The Mutagen Index, as an estimate for exposure to mutagenic or carcinogenic substances, was slightly positively associated with colon cancer risk in men (odds ratio = 1.3, 95% confidence interval = 1.0-1.7). No significant associations with colon cancer risk were observed for different NAT2 and GSTM1 gene variants. The observed associations with processed meat and the Mutagen Index were strongest for those with the intermediate or rapid NAT2 acetylator phenotype. Associations were not markedly influenced by lack of the GSTM1 gene. This study provides little support for an association between meat consumption and colon cancer risk but does provide some, albeit not strong, evidence for a modifying effect of molecular variants of the NAT2 gene.

  2. [Risk factors for methicillin-resistant Staphylococcus aureus bacteremia: A multicenter matched case-control study].

    PubMed

    Arias-Ortiz, Paola Mariana; Calderón, Libia Del Pilar; Castillo, Juan Sebastián; Moreno, José; Leal, Aura Lucía; Cortés, Jorge Alberto; Álvarez, Carlos Arturo; Grebo, Grupo

    2016-12-01

    Methicillin-resistant Staphylococcus aureus is a frequent pathogen at critical care services. Its presence leads to increased hospital stays and mortality risk in patients with bacteremia. However, the etiology of this resistance marker has not been fully studied. To identify risk factors associated with the emergence of methicillin-resistant S. aureus bacteremia in critically ill patients treated at intensive care units in Bogotá, Colombia. We conducted a retrospective paired case-control study, nested in a cohort of patients diagnosed with S. aureus bacteremia and treated at intensive care units between 2006 and 2008 in Bogotá. Cases were patients with positive blood culture to methicillin resistance, matched in a 1:1 ratio with methicillin-sensitive controls isolated from the same institution and hospitalization year. We used conditional logistic regression to analyze the risk factors associated with the presence of resistance, with emphasis on prior antibiotic therapy. We included 372 patients with S. aureus bacteremia. Factors such as the use of pre-hospital devices: vascular (OR=1.986, 95% CI 1.038 to 3.801) and urinary (OR=2.559, 95% CI: 1.170 to 5.596), along with the number of previously used antibiotics, were associated with the emergence of resistance. The number of antibiotics used previously was determined to have a gradient effect, particularly carbapenems. The rational use of antibiotics and surveillance of exposure to surgical procedures or use of invasive devices are interventions that could diminish the emergence of methicillin-resistant S. aureus bacteremia causes.

  3. 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

  4. Nocardia Infection in Solid Organ Transplant Recipients: A Multicenter European Case-control Study.

    PubMed

    Coussement, Julien; Lebeaux, David; van Delden, Christian; Guillot, Hélène; Freund, Romain; Marbus, Sierk; Melica, Giovanna; Van Wijngaerden, Eric; Douvry, Benoit; Van Laecke, Steven; Vuotto, Fanny; Tricot, Leïla; Fernández-Ruiz, Mario; Dantal, Jacques; Hirzel, Cédric; Jais, Jean-Philippe; Rodriguez-Nava, Veronica; Lortholary, Olivier; Jacobs, Frédérique

    2016-08-01

    Nocardiosis is a rare, life-threatening opportunistic infection, affecting 0.04% to 3.5% of patients after solid organ transplant (SOT). The aim of this study was to identify risk factors for Nocardia infection after SOT and to describe the presentation of nocardiosis in these patients. We performed a retrospective case-control study of adult patients diagnosed with nocardiosis after SOT between 2000 and 2014 in 36 European (France, Belgium, Switzerland, the Netherlands, Spain) centers. Two control subjects per case were matched by institution, transplant date, and transplanted organ. A multivariable analysis was performed using conditional logistic regression to identify risk factors for nocardiosis. One hundred and seventeen cases of nocardiosis and 234 control patients were included. Nocardiosis occurred at a median of 17.5 (range, 2-244) months after transplant. In multivariable analysis, high calcineurin inhibitor trough levels in the month before diagnosis (odds ratio [OR], 6.11; 95% confidence interval [CI], 2.58-14.51), use of tacrolimus (OR, 2.65; 95% CI, 1.17-6.00) and corticosteroid dose (OR, 1.12; 95% CI, 1.03-1.22) at the time of diagnosis, patient age (OR, 1.04; 95% CI, 1.02-1.07), and length of stay in the intensive care unit after SOT (OR, 1.04; 95% CI, 1.00-1.09) were independently associated with development of nocardiosis; low-dose cotrimoxazole prophylaxis was not found to prevent nocardiosis. Nocardia farcinica was more frequently associated with brain, skin, and subcutaneous tissue infections than were other Nocardia species. Among the 30 cases with central nervous system nocardiosis, 13 (43.3%) had no neurological symptoms. We identified 5 risk factors for nocardiosis after SOT. Low-dose cotrimoxazole was not found to prevent Nocardia infection. These findings may help improve management of transplant recipients. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For

  5. 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

  6. Occupational and environmental risk factors for idiopathic pulmonary fibrosis in Egypt: a multicenter case-control study.

    PubMed

    Awadalla, N J; Hegazy, A; Elmetwally, R A; Wahby, I

    2012-07-01

    Despite the advances in medical therapy and technology, the prognosis of idiopathic pulmonary fibrosis (IPF) remains poor and the need for disease prevention based on identifying the risk factors becomes mandatory. Occupational and environmental exposures were studied in several countries and found to play important role in the disease development. However, in Egypt, a little attention has been paid to study the effect of these factors in the disease development. To identify the occupational and environmental risk factors associated with the development of IPF in Egypt. A multicenter hospital-based case-control study was carried out in chest hospitals affiliated to three Egyptian cities-Cairo, Tanta and Mansoura. Subjects were 201 patients with confirmed IPF (cases) and 205 age-, sex- and residence-matched controls. Data on occupational and environmental factors were obtained from a questionnaire. Multiple logistic regression analysis was used to determine the independent risk factors of IPF in both sexes for single factors with adjustment for age, residence and smoking status. Compared with the controls, the risk of IPF in male workers was observed to increase significantly in chemical and petrochemical industries and carpentry and wood working (OR = 2.56, 95% CI: 1.02-7.01), and with occupational exposures to wood dust and wood preservatives. Among female workers, a significant increase was observed in farming (OR = 3.34, 95% CI: 1.17-10.12), raising birds and occupational exposures to animal feeds, products and dusts and pesticides. Risk of IPF decreased significantly in male workers and insignificantly among female workers in sales and clerical related activities. The environmental exposures to birds and cats were significantly associated with elevated risk of IPF development in both sexes. In Egypt, farming, raising birds and wood working are important risk factors for the development of IPF.

  7. Occupation and risk of lung cancer in Central and Eastern Europe: the IARC multi-center case-control study.

    PubMed

    Bardin-Mikolajczak, Alicja; Lissowska, Jolanta; Zaridze, David; Szeszenia-Dabrowska, Neonila; Rudnai, Peter; Fabianova, Eleonora; Mates, Dana; Navratilova, Marie; Bencko, Vladimir; Janout, Vladimir; Fevotte, Joelle; Fletcher, Tony; 't Mannetje, Andrea; Brennan, Paul; Boffetta, Paolo

    2007-08-01

    We sought to evaluate the role of occupation and industry in lung carcinogenesis in six countries in Central and Eastern Europe. This multi-center case-control study included 2,056 male and 576 female lung cancer incidence cases diagnosed from 1998 to 2001 and 2,144 male and 727 female controls frequency-matched for sex and age. Unconditional regression models were applied to calculate the odds ratios after controlling for potential confounders including age (5-year groups), study center (15 centers), and tobacco pack-years. Elevated odds ratios (ORs) were found for men employed as production workers (OR 1.45, 95% CI 1.22-1.72), bookkeepers and cashiers (1.81, 1.03-3.24), general farmers (1.67, 1.08-2.60), livestock workers (2.54, 1.09-5.88), miners (2.17, 1.47-3.23), toolmakers and metal patternmakers (2.56, 1.34-4.94), glass formers (2.55, 1.18-5.50), dockworkers, and freight handlers (1.49, 1.04-2.12). Industries with elevated risk among men included mining (1.75, 1.20-2.57), manufacture of cement, lime, or plaster (3.62, 1.11-12.00), casting of metals (2.00, 1.17-3.45), manufacture of electric motors (2.18, 1.24-3.86). For women, elevated ORs were found for medical, dental, veterinary doctors (2.54, 1.01-6.31), librarians and curators (7.03, 1.80-27.80), sewers 3.63 (1.12-10.23). This study identifies new areas for further, explanatory analyses, especially in production work, and indicates new possible sources of exposure to cancer risk for women.

  8. Protocol of the Stroke in Korean Young Adults Study: A Multicenter Case-Control Study and Prospective Cohort Study.

    PubMed

    Kwon, Hyuk Sung; Kim, Chulho; Lee, Seung-Hoon; Jung, Keun-Hwa; Kim, Young Dae; Kwon, Hyung-Min; Heo, Sung Hyuk; Chang, Dae-Il; Kim, Beom Joon; Kim, Jeong-Min; Kim, Hyun Young; Kim, Young Seo

    2016-06-01

    The incidence of ischemic stroke in young adults has been rising over recent decades, but there is still limited information on its risk factors, etiologies, and outcomes. Because these patients generally participate in social life, risk factors associated with lifestyle may have a great impact and need to be identified. The SKY (Stroke in Korean Young Adults) study is a multicenter case-control study and a prospective cohort study in 8 tertiary medical centers in the Republic of Korea. The case subjects are patients aged 18-44 years with first-ever ischemic stroke occurring within 1 month of stroke onset, and the control subjects are age- and gender-matched community controls. Our aim is to include 470 cases and 470 controls. The main objective of our study is to determine the risk factors and the causes of ischemic stroke in Korean young adults. Both well-documented risk factors and little-known lifestyle-related risk factors such as lifestyle habits and psychological distress including job strain will be evaluated by comparing cases and controls using a structured questionnaire. Secondary objectives are to determine the risks of mortality, recurrent vascular events, and poststroke epilepsy in these patients. Conditional logistic regression analysis will be used to estimate odds ratios and 95% confidence intervals. The SKY study is designed to obtain more insights into relatively little-known risk factors in young Korean adults with ischemic stroke. The results may also help identify the frequencies of uncommon etiologies and outcomes in these patients. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  9. 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. Copyright © 2013 UICC.

  10. Adult female acne and associated risk factors: Results of a multicenter case-control study in Italy.

    PubMed

    Di Landro, Anna; Cazzaniga, Simone; Cusano, Francesco; Bonci, Angela; Carla, Cardinali; Musumeci, Maria Letizia; Patrizi, Annalisa; Bettoli, Vincenzo; Pezzarossa, Enrico; Caproni, Marzia; Fortina, Anna Belloni; Campione, Elena; Ingordo, Vito; Naldi, Luigi

    2016-12-01

    The reasons for the appearance of acne in adulthood are largely unknown. We explored the role of personal and environmental factors in adult female acne. We conducted a multicenter case-control study in the outpatient departments of 12 Italian cities. Cases (n = 248) were consecutive women ≥25 years of age with newly diagnosed acne of any grade. Controls (n = 270) were females diagnosed with conditions other than acne. In multivariate analysis, a history of acne in parents (odds ratio [OR] = 3.02) or siblings (OR = 2.40), history of acne during adolescence (OR = 5.44), having no previous pregnancies (OR = 1.71), having hirsutism (OR = 3.50), being an office worker versus being unemployed or being a housewife (OR = 2.24), and having a high level of reported psychological stress (OR = 2.95) were all associated with acne. A low weekly intake of fruits or vegetables (OR = 2.33) and low consumption of fresh fish (OR = 2.76) were also associated with acne. We did not establish an onset date for acne. Some of our associations may reflect consequences of established acne. Lifestyle factors may play an important role for acne development in adulthood, but their role should be further assessed in prospective studies. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  11. Efficacy of sublingual specific immunotherapy in intermittent and persistent allergic rhinitis in children: an observational case-control study on 171 patients. The EFESO-children multicenter trial.

    PubMed

    Acquistapace, Franca; Agostinis, Fabio; Castella, Vincenzo; Kantar, Ahmad; Novembre, Elio; Perrone, Maria Rosaria; Pietrasanta, Michele; Sambugaro, Renato; Milani, Massimo

    2009-11-01

    Sublingual-specific immunotherapy (SLIT) is considered as a valid treatment of respiratory allergies. However, there are few data on large sample size regarding its clinical role in 'real life' in term of reduction of symptoms, rescue medications and prevention of asthma in patients suffering from allergic rhinitis (AR) especially in children. We performed a multicenter, case-control study to evaluate the effect of SLIT in children (age 6-18 yr) with intermittent or persistent AR. 171 children (27% girls and 73% boys) with AR due to seasonal or perennial allergens were enrolled in a multicenter case-control study. Cases (n = 90) were defined as patients with intermittent (64%) or persistent (36%) AR who were treated for at least two consecutive years with specific SLIT with the related allergen extracts (SLITone ALK-Abellò). Controls (n = 81) were defined as sex-age- and type of allergen matched AR children who were never treated with specific immunotherapy and had no asthmatic symptoms at the beginning of observation period. Main outcomes of the study were the rhinoconjunctivitis symptom score (SS) (sneezing, rhinorrea, nasal itch, congestion, ocular itch and watery eyes) with a ranging scale from 0 (=no symptoms) to 3 (=severe symptoms) and the medication score (MS) evaluating symptomatic drug intake (antihystamine and inhaled corticosteroids). SS and MS were evaluated at the end of the observational period in relation with the period, considering the last 12 months, in which patients suffered the highest symptoms levels (i.e., peak of relevant pollen season (seasonal AR) or during the period of maximum allergen exposure in case of perennial AR). Secondary outcome of the study was the development of asthma symptoms during the observation period. SS (mean +/- SD) was 4.5 +/- 2.5 in cases and 9.0 +/- 3.0 in controls (-50%) (p = 0.0001). MS (mean +/- SD) was 2.5 +/- 1.9 and 3.6 +/- 2.1 in the case and control groups, respectively (-31%) (p = 0.0001). At the end of

  12. 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...

  13. Factors associated to temporal artery biopsy result in suspects of giant cell arteritis: a retrospective, multicenter, case-control study.

    PubMed

    González-López, Julio J; González-Moraleja, Julio; Burdaspal-Moratilla, Ana; Rebolleda, Gema; Núñez-Gómez-Álvarez, María T; Muñoz-Negrete, Francisco J

    2013-12-01

    To evaluate the positivity rate of temporal artery biopsies (TAB) performed in suspects of giant cell arteritis (GCA) and to study the epidemiological and clinical factors associated to the biopsy result. A retrospective, multicenter, case-control study was performed, including three hundred and thirty-five patients who underwent TAB for a suspicion of GCA from 2001 to 2010. Clinical, epidemiological and pathology data were recovered from the patients' clinical records. Histologic diagnosis of GCA was made when active inflammation or giant cells were found in the arterial wall. Eighty-one biopsies (24.2%) were considered positive for GCA. Clinical factors independently associated to TAB result in a logistic regression analysis were temporal cutaneous hyperalgesia (OR = 10.8; p < 0.001), jaw claudication (OR = 4.6; p = 0.001), recent-onset headache (OR = 4.4; p = 0.001), decreased temporal pulse (OR = 2.8; p = 0.02), pain and stiffness in neck and shoulders (OR = 2.3; p = 0.05), unintentional weight loss (OR = 1.33; p = 0.003) and age (OR = 1.085; p = 0.004). Other factors such as length of the surgical specimen (OR = 1.079; p = 0.028) and erythrocyte sedimentation rate (OR = 1.042; p < 0.001) were also statistically significant. The model was accurate (C-index = 0.921), reliable (pHosmer-Lemeshow = 0.733) and consistent in the bootstrap sensitivity analysis. No significant association was detected between TAB result and number of days of previous systemic corticosteroid treatment (p = 0.146). However, an association was observed between TAB result and the total accumulated dose of previous systemic corticotherapy (p = 0.043). Exhaustive anamnesis and clinical examination remain of paramount importance in the diagnosis of GCA. To improve the yield of TAB, it should be performed specially in older patients with GCA-compatible clinic. TAB could be avoided in patients with an isolated elevation of acute phase reactants, without GCA-compatible clinic. © 2012 The

  14. 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

  15. Microorganisms Associated With Pneumonia in Children <5 Years of Age in Developing and Emerging Countries: The GABRIEL Pneumonia Multicenter, Prospective, Case-Control Study.

    PubMed

    Bénet, Thomas; Sánchez Picot, Valentina; Messaoudi, Mélina; Chou, Monidarin; Eap, Tekchheng; Wang, Jianwei; Shen, Kunling; Pape, Jean-William; Rouzier, Vanessa; Awasthi, Shally; Pandey, Nitin; Bavdekar, Ashish; Sanghavi, Sonali; Robinson, Annick; Rakoto-Andrianarivelo, Mala; Sylla, Maryam; Diallo, Souleymane; Nymadawa, Pagbajabyn; Naranbat, Nymadawaagiin; Russomando, Graciela; Basualdo, Wilma; Komurian-Pradel, Florence; Endtz, Hubert; Vanhems, Philippe; Paranhos-Baccalà, Gláucia

    2017-06-12

    Pneumonia, the leading infectious cause of child mortality globally, mainly afflicts developing countries. This prospective observational study aimed to assess the microorganisms associated with pneumonia in children aged <5 years in developing and emerging countries. A multicenter, case-control study by the GABRIEL (Global Approach to Biological Research, Infectious diseases and Epidemics in Low-income countries) network was conducted between 2010 and 2014 in Cambodia, China, Haiti, India (2 sites), Madagascar, Mali, Mongolia, and Paraguay. Cases were hospitalized children with radiologically confirmed pneumonia; controls were children from the same setting without any features suggestive of pneumonia. Nasopharyngeal swabs were collected from all subjects; 19 viruses and 5 bacteria were identified by reverse-transcription polymerase chain reaction. Associations between microorganisms and pneumonia were quantified by calculating the adjusted population attributable fraction (aPAF) after multivariate logistic regression analysis adjusted for sex, age, time period, other pathogens, and site. Overall, 888 cases and 870 controls were analyzed; ≥1 microorganism was detected in respiratory samples in 93.0% of cases and 74.4% of controls (P < .001). Streptococcus pneumoniae, Mycoplasma pneumoniae, human metapneumovirus, rhinovirus, respiratory syncytial virus (RSV), parainfluenza virus 1, 3, and 4, and influenza virus A and B were independently associated with pneumonia; aPAF was 42.2% (95% confidence interval [CI], 35.5%-48.2%) for S. pneumoniae, 18.2% (95% CI, 17.4%-19.0%) for RSV, and 11.2% (95% CI, 7.5%-14.7%) for rhinovirus. Streptococcus pneumoniae, RSV, and rhinovirus may be the major microorganisms associated with pneumonia infections in children <5 years of age from developing and emerging countries. Increasing S. pneumoniae vaccination coverage may substantially reduce the burden of pneumonia among children in developing countries.

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

    PubMed

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

    2001-01-01

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

  17. 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

  18. An incidence density sampling program for nested case-control analyses

    PubMed Central

    Richardson, D

    2004-01-01

    Methods: This paper presents a simple computer program for incidence density sampling. This program was evaluated using data derived from a cohort study of mortality among workers employed in the nuclear weapons industry. Controls were selected for cases via incidence density sampling; an estimate of the exposure-mortality association was obtained via conditional logistic regression. After 100 iterations of this procedure, the average effect estimate was compared to the risk estimate obtained via proportional hazards regression. The same methods were used to evaluate a program for incidence density sampling that was proposed previously by Pearce in 1989.5 Results: Relative risk estimates obtained from nested case-control analyses conducted using the incidence density sampling program reported in this paper are unbiased. In contrast, the program for incidence density sampling proposed by Pearce5 tended to produce biased relative risk estimates; the magnitude of bias increased with increasing numbers of controls selected per case. Conclusions: The computer program described in this paper offers a simple approach to incidence density sampling for nested case-control analyses with exact matching on attained age and appropriate enumeration of the pool of eligible controls for each case. This method overcomes problems of bias inherent in a previously proposed program for incidence density sampling. PMID:15550597

  19. 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.

  20. 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).

  1. 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

  2. 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

  3. Burden and aetiology of diarrhoeal disease in infants and young children in developing countries (the Global Enteric Multicenter Study, GEMS): a prospective, case-control study.

    PubMed

    Kotloff, Karen L; Nataro, James P; Blackwelder, William C; Nasrin, Dilruba; Farag, Tamer H; Panchalingam, Sandra; Wu, Yukun; Sow, Samba O; Sur, Dipika; Breiman, Robert F; Faruque, Abu Sg; Zaidi, Anita Km; Saha, Debasish; Alonso, Pedro L; Tamboura, Boubou; Sanogo, Doh; Onwuchekwa, Uma; Manna, Byomkesh; Ramamurthy, Thandavarayan; Kanungo, Suman; Ochieng, John B; Omore, Richard; Oundo, Joseph O; Hossain, Anowar; Das, Sumon K; Ahmed, Shahnawaz; Qureshi, Shahida; Quadri, Farheen; Adegbola, Richard A; Antonio, Martin; Hossain, M Jahangir; Akinsola, Adebayo; Mandomando, Inacio; Nhampossa, Tacilta; Acácio, Sozinho; Biswas, Kousick; O'Reilly, Ciara E; Mintz, Eric D; Berkeley, Lynette Y; Muhsen, Khitam; Sommerfelt, Halvor; Robins-Browne, Roy M; Levine, Myron M

    2013-07-20

    Diarrhoeal diseases cause illness and death among children younger than 5 years in low-income countries. We designed the Global Enteric Multicenter Study (GEMS) to identify the aetiology and population-based burden of paediatric diarrhoeal disease in sub-Saharan Africa and south Asia. The GEMS is a 3-year, prospective, age-stratified, matched case-control study of moderate-to-severe diarrhoea in children aged 0-59 months residing in censused populations at four sites in Africa and three in Asia. We recruited children with moderate-to-severe diarrhoea seeking care at health centres along with one to three randomly selected matched community control children without diarrhoea. From patients with moderate-to-severe diarrhoea and controls, we obtained clinical and epidemiological data, anthropometric measurements, and a faecal sample to identify enteropathogens at enrolment; one follow-up home visit was made about 60 days later to ascertain vital status, clinical outcome, and interval growth. We enrolled 9439 children with moderate-to-severe diarrhoea and 13,129 control children without diarrhoea. By analysing adjusted population attributable fractions, most attributable cases of moderate-to-severe diarrhoea were due to four pathogens: rotavirus, Cryptosporidium, enterotoxigenic Escherichia coli producing heat-stable toxin (ST-ETEC; with or without co-expression of heat-labile enterotoxin), and Shigella. Other pathogens were important in selected sites (eg, Aeromonas, Vibrio cholerae O1, Campylobacter jejuni). Odds of dying during follow-up were 8·5-fold higher in patients with moderate-to-severe diarrhoea than in controls (odd ratio 8·5, 95% CI 5·8-12·5, p<0·0001); most deaths (167 [87·9%]) occurred during the first 2 years of life. Pathogens associated with increased risk of case death were ST-ETEC (hazard ratio [HR] 1·9; 0·99-3·5) and typical enteropathogenic E coli (HR 2·6; 1·6-4·1) in infants aged 0-11 months, and Cryptosporidium (HR 2·3; 1·3-4·3

  4. 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

  5. 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.

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

    DTIC Science & Technology

    2015-01-01

    both WRNMMC (45) and UPITT (21), male or female, ages 18 years of age and older with wounds requiring skin grafts will be asked to participate...AD______________ AWARD NUMBER: W81XWH-13-2-0031 TITLE: Autologous Skin Cell Spray for Massive Soft Tissue War Injuries: A Prospective, Case...DATES COVERED 15Mar2013-31Oct2014 4. TITLE AND SUBTITLE Autologous Skin Cell Spray for Massive Soft Tissue War Injuries: A Prospective, Case-Control

  7. Lack of association of CASC8 rs1447295 with colorectal cancer in Iranian population: A multicenter case-control study.

    PubMed

    Haerian, Monir Sadat; Haerian, Batoul Sadat; Molanaei, Saadat; Kosari, Farid; Sabeti, Shahram; Bidari-Zerehpoosh, Farahnaz; Abdolali, Ebrahim

    2017-11-15

    Several studies reported the potential role of the rs1447295 polymorphism in susceptibility to cancer. This variant located in the cancer susceptibility candidate 8 (CASC8) is a long noncoding RNA (lnRNA) gene and does not code protein. LnRNA transcripts play a potential regulatory role in the expression of key genes involved in multiple cellular pathways, including cell cycle, pluripotency, and immune response. The aim of this study is to evaluate this association with colorectal cancer (CRC) in a large case-control study of the Iranian population. After extraction of genomic DNA by the standard protocols, the rs1447295 was genotyped in 2416 subjects (46% patients). Results of this case-control demonstrated no significant association between the rs1447295 polymorphism and risk of CRC or its characteristics under allele or alternative genotype models. In conclusion, it is unlikely that the rs1447295 polymorphism is a risk variant for the development of CRC in Iranian population. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. A web application for sample size and power calculation in case-control microbiome studies.

    PubMed

    Mattiello, Federico; Verbist, Bie; Faust, Karoline; Raes, Jeroen; Shannon, William D; Bijnens, Luc; Thas, Olivier

    2016-07-01

    : When designing a case-control study to investigate differences in microbial composition, it is fundamental to assess the sample sizes needed to detect an hypothesized difference with sufficient statistical power. Our application includes power calculation for (i) a recoded version of the two-sample generalized Wald test of the 'HMP' R-package for comparing community composition, and (ii) the Wilcoxon-Mann-Whitney test for comparing operational taxonomic unit-specific abundances between two samples (optional). The simulation-based power calculations make use of the Dirichlet-Multinomial model to describe and generate abundances. The web interface allows for easy specification of sample and effect sizes. As an illustration of our application, we compared the statistical power of the two tests, with and without stratification of samples. We observed that statistical power increases considerably when stratification is employed, meaning that less samples are needed to detect the same effect size with the same power. The web interface is written in R code using Shiny (RStudio Inc., 2016) and it is available at https://fedematt.shinyapps.io/shinyMB The R code for the recoded generalized Wald test can be found at https://github.com/mafed/msWaldHMP CONTACT: Federico.Mattiello@UGent.be. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  9. Characterizing restless legs syndrome and leg motor restlessness in patients with Parkinson's disease: A multicenter case-controlled study.

    PubMed

    Suzuki, Keisuke; Okuma, Yasuyuki; Uchiyama, Tomoyuki; Miyamoto, Masayuki; Sakakibara, Ryuji; Shimo, Yasushi; Hattori, Nobutaka; Kuwabara, Satoshi; Yamamoto, Toshimasa; Kaji, Yoshiaki; Hirano, Shigeki; Numao, Ayaka; Hirata, Koichi

    2017-08-14

    We investigated the prevalence and impact of restless legs syndrome (RLS) and leg motor restlessness (LMR) in patients with Parkinson's disease (PD) in a multicenter study. A total of 436 PD patients and 401 age- and sex-matched controls were included in this study. RLS was diagnosed based on four essential features. LMR was diagnosed when a participant exhibited the urge to move his or her legs but did not meet the four essential features of RLS. The RLS prevalence did not differ between PD patients and controls (3.4% vs. 2.7%), while LMR prevalence was significantly higher in PD patients than in controls (12.8% vs. 4.5%). PD patients with RLS or LMR had a higher prevalence of excessive daytime sleepiness (EDS) (50.7%, vs. 6.9%), probable REM sleep behavior disorder (38.0% vs. 3.4%) and PD-related sleep problems (49.3% vs. 20.7%) than controls with RLS or LMR. RLS/LMR preceding PD onset was related to an older age of PD onset. Our study revealed an increased prevalence of LMR but not RLS in PD patients. LMR could be an early manifestation of PD; however, whether LMR is within the range of RLS or whether LMR and RLS constitute different entities in PD requires further studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. XM: Association Testing on the X-Chromosome in Case-Control Samples with Related Individuals

    PubMed Central

    Thornton, Timothy; Zhang, Qian; Cai, Xiaochen; Ober, Carole; McPeek, Mary Sara

    2013-01-01

    Genetic variants on the X-chromosome could potentially play an important role in some complex traits. However, development of methods for detecting association with X-linked markers has lagged behind that for autosomal markers. We propose methods for case-control association testing with X-chromosome markers in samples with related individuals. Our method, XM, appropriately adjusts for both correlation among relatives and male-female allele copy number differences. Features of XM include: (1) it is applicable to and computationally feasible for completely general combinations of family and case-control designs; (2) it allows for both unaffected controls and controls of unknown phenotype to be included in the same analysis; (3) it can incorporate phenotype information on relatives with missing genotype data; and (4) it adjusts for sex-specific trait prevalence values. We propose two other tests, Xχ and XW, which can also be useful in certain contexts. We derive the best linear unbiased estimator of allele frequency, and its variance, for X-linked markers. In simulation studies with related individuals, we demonstrate the power and validity of the proposed methods. We apply the methods to X-chromosome association analysis of (1) asthma in a Hutterite sample and (2) alcohol dependence in the GAW 14 COGA data. In analysis (1), we demonstrate computational feasibility of XM and the applicability of our robust variance estimator. In analysis (2), we detect significant association, after Bonferroni correction, between alcohol dependence and SNP rs979606 in the MAOA gene, where this gene has previously been found to be associated with substance abuse and antisocial behavior. PMID:22552845

  11. Pre-Illness Isoflavone Consumption and Disease Risk of Ulcerative Colitis: A Multicenter Case-Control Study in Japan

    PubMed Central

    Ohfuji, Satoko; Fukushima, Wakaba; Watanabe, Kenji; Sasaki, Satoshi; Yamagami, Hirokazu; Nagahori, Masakazu; Watanabe, Mamoru; Hirota, Yoshio

    2014-01-01

    Introduction Previous studies have suggested that estrogens play a role in the development of ulcerative colitis (UC). Because isoflavones have a similar structure to 17β-estradiol, dietary consumption of isoflavones may have similar influences on the development of UC. We examined the association between pre-illness isoflavone consumption and the risk of UC. Materials and Methods We conducted a hospital-based case control study, and compared the dietary habits of 126 newly diagnosed UC cases with those of 170 age- and gender-matched hospital controls. Information on dietary factors was collected using a self-administered diet history questionnaire. To consider potential changes in dietary habits due to disease symptoms, the habits were assessed separately during the previous 1 month and at 1 year before the recruitment. Results In the assessment of dietary habits during the previous 1 month, the highest tertile of isoflavone consumption revealed an increased odds ratio (OR) for UC (OR = 2.79; 95% confidence interval (CI), 1.39–5.59; Trend P = 0.004). A significant association was also observed for the dietary assessment at 1 year before, when most UC cases had not yet experienced their first disease symptoms (OR = 2.06; 95% CI, 1.05–4.04; Trend P = 0.04). Associations were more pronounced in females (OR in highest tertile of isoflavone consumption at 1 year before = 4.76; 95% CI, 1.30–17.5; Trend P = 0.02) but were obscured in males (corresponding OR = 1.21; 95% CI, 0.49–3.01; Trend P = 0.63). Conclusions Dietary isoflavone consumption may be associated with an increased risk of UC, particularly in females. Prospective cohort studies are warranted to confirm these findings. PMID:25314032

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. A non-endoscopic device to sample the oesophageal microbiota: a case-control study.

    PubMed

    Elliott, Daffolyn R Fels; Walker, Alan W; O'Donovan, Maria; Parkhill, Julian; Fitzgerald, Rebecca C

    2017-01-01

    The strongest risk factor for oesophageal adenocarcinoma is reflux disease, and the rising incidence of this coincides with the eradication of Helicobacter pylori, both of which might alter the oesophageal microbiota. We aimed to profile the microbiota at different stages of Barrett's carcinogenesis and investigate the Cytosponge as a minimally invasive tool for sampling the oesophageal microbiota. In this case-control study, 16S rRNA gene amplicon sequencing was done on 210 oesophageal samples from 86 patients representing the Barrett's oesophagus progression sequence (normal squamous controls [n=20], non-dysplastic [n=24] and dysplastic Barrett's oesophagus [n=23], and oesophageal adenocarcinoma [n=19]), relevant negative controls, and replicates on the Illumina MiSeq platform. Samples were taken from patients enrolled in the BEST2 study at five UK hospitals and the OCCAMS study at six UK hospitals. We compared fresh frozen tissue, fresh frozen endoscopic brushings, and the Cytosponge device for microbial DNA yield (qPCR), diversity, and community composition. There was decreased microbial diversity in oesophageal adenocarcinoma tissue compared with tissue from healthy control patients as measured by the observed operational taxonomic unit (OTU) richness (p=0·0012), Chao estimated total richness (p=0·0004), and Shannon diversity index (p=0·0075). Lactobacillus fermentum was enriched in oesophageal adenocarcinoma (p=0·028), and lactic acid bacteria dominated the microenvironment in seven (47%) of 15 cases of oesophageal adenocarcinoma. Comparison of oesophageal sampling methods showed that the Cytosponge yielded more than ten-times higher quantities of microbial DNA than did endoscopic brushes or biopsies using quantitative PCR (p<0·0001). The Cytosponge samples contained the majority of taxa detected in biopsy and brush samples, but were enriched for genera from the oral cavity and stomach, including Fusobacterium, Megasphaera, Campylobacter, Capnocytophaga

  17. Asymptotic Properties of the Sequential Empirical ROC, PPV and NPV Curves Under Case-Control Sampling

    PubMed Central

    Koopmeiners, Joseph S.; Feng, Ziding

    2013-01-01

    The receiver operating characteristic (ROC) curve, the positive predictive value (PPV) curve and the negative predictive value (NPV) curve are three measures of performance for a continuous diagnostic biomarker. The ROC, PPV and NPV curves are often estimated empirically to avoid assumptions about the distributional form of the biomarkers. Recently, there has been a push to incorporate group sequential methods into the design of diagnostic biomarker studies. A thorough understanding of the asymptotic properties of the sequential empirical ROC, PPV and NPV curves will provide more flexibility when designing group sequential diagnostic biomarker studies. In this paper we derive asymptotic theory for the sequential empirical ROC, PPV and NPV curves under case-control sampling using sequential empirical process theory. We show that the sequential empirical ROC, PPV and NPV curves converge to the sum of independent Kiefer processes and show how these results can be used to derive asymptotic results for summaries of the sequential empirical ROC, PPV and NPV curves. PMID:24039313

  18. Physical workload and accelerated occurrence of lumbar spine diseases: risk and rate advancement periods in a German multicenter case-control study.

    PubMed

    Seidler, Andreas; Euler, Ulrike; Bolm-Audorff, Ulrich; Ellegast, Rolf; Grifka, Joachim; Haerting, Johannes; Jäger, Matthias; Michaelis, Martina; Kuss, Oliver

    2011-01-01

    In a German multicenter case-control study of lumbar disc diseases, we calculated risk and rate advancement periods (RAP) for physical workload. Patients aged 25-70 years with clinically and radiologically verified lumbar disc herniation (286 males, 278 females) or symptomatic lumbar disc narrowing (145 males, 206 females) were compared with population control subjects (453 males and 448 females). For this analysis, all manual handling of objects of about ≥5 kg and postures with trunk inclination of ≥20 °, as assessed by technical experts, were included in the calculation of cumulative lumbar load, determined by biomechanical model calculations. Logistic regression analysis was applied to calculate RAP, adjusted for region. We found a steep positive dose-response relationship between age and lumbar disc narrowing among men as well as women; however, we did not find a monotonic increase in lumbar disc herniation risk with age. As a monotonic increase in disease risk with age constitutes a fundamental assumption underlying the RAP concept, we restricted our RAP analysis to cases with symptomatic lumbar disc narrowing. Among men, there was a positive dose-response relationship between the cumulative lumbar load and the acceleration of lumbar disc narrowing. In the highest exposure category, a RAP of 28.0 years [95% confidence interval (95% CI) 9.7-46.3 years] was found. Among women, the RAP was 8.8 years (95% CI 2.4-15.2 years) in the highest exposure category. This study emphasizes the conceptual importance of risk acceleration - causation not only comprises the occurrence of a disease (that without a specific exposure would not have occurred at all) but also the accelerated occurrence of a disease (that without exposure would have occurred later in life).

  19. 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

  20. Retrospective multicenter matched case-control study on the risk factors for narcolepsy with special focus on vaccinations (including pandemic influenza vaccination) and infections in Germany.

    PubMed

    Oberle, Doris; Pavel, Jutta; Mayer, Geert; Geisler, Peter; Keller-Stanislawski, Brigitte

    2017-06-01

    Studies associate pandemic influenza vaccination with narcolepsy. In Germany, a retrospective, multicenter, matched case-control study was performed to identify risk factors for narcolepsy, particularly regarding vaccinations (seasonal and pandemic influenza vaccination) and infections (seasonal and pandemic influenza) and to quantify the detected risks. Patients with excessive daytime sleepiness who had been referred to a sleep center between April 2009 and December 2012 for multiple sleep latency test (MSLT) were eligible. Case report forms were validated according to the criteria for narcolepsy defined by the Brighton Collaboration (BC). Confirmed cases of narcolepsy (BC level of diagnostic certainty 1-4a) were matched with population-based controls by year of birth, gender, and place of residence. A second control group was established including patients in whom narcolepsy was definitely excluded (test-negative controls). A total of 103 validated cases of narcolepsy were matched with 264 population-based controls. The second control group included 29 test-negative controls. A significantly increased odd ratio (OR) to develop narcolepsy (crude OR [cOR] = 3.9, 95% confidence interval [CI] = 1.8-8.5; adjusted OR [aOR] = 4.5, 95% CI = 2.0-9.9) was detected in individuals immunized with pandemic influenza A/H1N1/v vaccine prior to symptoms onset as compared to nonvaccinated individuals. Using test-negative controls, in individuals immunized with pandemic influenza A/H1N1/v vaccine prior to symptoms onset, a nonsignificantly increased OR of narcolepsy was detected when compared to nonvaccinated individuals (whole study population, BC levels 1-4a: cOR = 1.9, 95% CI = 0.5-6.9; aOR = 1.8, 95% CI = 0.3-10.1). The findings of this study support an increased risk for narcolepsy after immunization with pandemic influenza A/H1N1/v vaccine. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Clinical predictors of methicillin-resistant Staphylococcus aureus in nosocomial and healthcare-associated pneumonia: a multicenter, matched case-control study.

    PubMed

    Torre-Cisneros, J; Natera, C; Mesa, F; Trikic, M; Rodríguez-Baño, J

    2017-09-08

    The situations in which coverage for methicillin-resistant Staphylococcus aureus (MRSA) in the empirical treatment of nosocomial pneumonia (NP) or severe healthcare-associated pneumonia (HCAP) is needed are poorly defined, particularly outside intensive care units (ICUs). Our aim was to characterize if the risk of MRSA NP/HCAP can be defined by clinical variables. We designed an observational, retrospective, multicenter, case-control study to analyze the association between defined clinical variables and risk of MRSA NP/HCAP in non-ICU patients using conditional multivariable logistic regression. Cases and controls (1:2) with microbiological diagnosis were included. Controls were matched for hospital, type of pneumonia (NP or HCAP), and date of isolation. A total of 140 cases (77 NP and 63 HCAP) and 280 controls were studied. The variables associated with the risk of MRSA pneumonia were: (i) respiratory infection/colonization caused by MRSA in the previous year [odds ratio (OR) 14.81, 95% confidence interval (CI) 4.13-53.13, p < 0.001]; (ii) hospitalization in the previous 90 days (OR 2.41, 95% CI 1.21-4.81, p = 0.012); and (iii) age (OR 1.02, 95% CI 1.001-1.05, p = 0.040). The area under the receiver operating characteristic (ROC) curve for the multivariable model was 0.72 (95% CI 0.66-0.78). The multivariate model had a sensitivity of 74.5% (95% CI 65.3-83.6), a specificity of 63.3% (95% CI 56.0-70.6), a positive predictive value of 52.5% (95% CI 43.9-61.2), and a negative predictive value of 82.0% (95% CI 75.3-88.8) for the observed data. Clinical predictors of MRSA NP/HCAP can be used to define a low-risk population in whom coverage against MRSA may not be needed.

  2. Alternative population sampling frames produced important differences in estimates of association: a case-control study of vasculitis.

    PubMed

    Macfarlane, Gary J; Jones, Gareth T; Swafe, Leyla; Reid, David M; Basu, Neil

    2013-06-01

    A common population sampling frame in countries with universal health care is health service registers. We have evaluated the use of such a register, in the United Kingdom, against a commercially available database claiming large population coverage, an alternative that offers ease of access and flexibility of use. A case-control study of vasculitis, which recruited cases from secondary care clinics in Scotland, compared two alternative sampling frames for population controls, namely the registers of National Health Service (NHS) primary care practices and a commercially available database. The characteristics of controls recruited from both sources were compared in addition to separate case-control comparison using logistic regression. A total of 166 of 189 cases participated (88% participation rate), while both the commercial database and NHS Central Register (NHSCR) controls achieved a participation rate of 24% among persons assumed to have received the invitation. On several measures, the NHSCR patients reported poorer health than the commercial database controls: low scores on the physical component score of the Short Form 36 (odds ratio [OR]: 2.3; 95% confidence interval [CI]: 1.3-4.1), chronic widespread pain (OR: 2.3; CI: 1.1-4.7), and high levels of fatigue (OR: 2.0; CI: 1.3-3.1). These had an important influence on the estimates of association with case status with one association (pain) showing a strong and significant association using commercial database controls, which was absent with NHSCR controls. There are important differences in self-reported measures of health and quality of life using controls from two alternative population sampling frames. It emphasizes the importance of methodological rigor and prior assessment in choosing sampling frames for case-control studies. Copyright © 2013 Elsevier Inc. All rights reserved.

  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. Adjusting for outcome misclassification: the importance of accounting for case-control sampling and other forms of outcome-related selection.

    PubMed

    Jurek, Anne M; Maldonado, George; Greenland, Sander

    2013-03-01

    Special care must be taken when adjusting for outcome misclassification in case-control data. Basic adjustment formulas using either sensitivity and specificity or predictive values (as with external validation data) do not account for the fact that controls are sampled from a much larger pool of potential controls. A parallel problem arises in surveys and cohort studies in which participation or loss is outcome related. We review this problem and provide simple methods to adjust for outcome misclassification in case-control studies, and illustrate the methods in a case-control birth certificate study of cleft lip/palate and maternal cigarette smoking during pregnancy. Adjustment formulas for outcome misclassification that ignore case-control sampling can yield severely biased results. In the data we examined, the magnitude of error caused by not accounting for sampling is small when population sensitivity and specificity are high, but increases as (1) population sensitivity decreases, (2) population specificity decreases, and (3) the magnitude of the differentiality increases. Failing to account for case-control sampling can result in an odds ratio adjusted for outcome misclassification that is either too high or too low. One needs to account for outcome-related selection (such as case-control sampling) when adjusting for outcome misclassification using external information. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Comparing the Asthma APGAR system and the Asthma Control Test™ in a multicenter primary care sample.

    PubMed

    Rank, Matthew A; Bertram, Susan; Wollan, Peter; Yawn, Roy A; Yawn, Barbara P

    2014-07-01

    To compare asthma control assessment using the Asthma APGAR system, a tool developed by primary care clinicians, in a multicenter primary care sample with the Asthma Control Test (ACT™)/Childhood Asthma Control Test (CACT™), a tool developed by asthma specialists. This is a substudy of a multicenter, randomized, controlled pragmatic trial that tests the effectiveness of the Asthma APGAR system in primary care practices. As part of the study, enrolled patients completed both the ACT™/CACT™ and the Asthma APGAR system between March 1, 2011, and December 31, 2011. Kappa and McNemar statistics were used to compare the results of questionnaires. Of the 468 patients in our sample, 306 (65%) were classified as not controlled by the ACT™/CACT™ or the Asthma APGAR system. The overall agreement was 84.4%, with a kappa value of .68 (substantial agreement) and a McNemar test P value of .35 (suggesting no significant difference in the direction of disagreement). Of those with poor control as defined by the Asthma APGAR system, 23.8% (73) had no controller medications and 76.5% (234) were seldom or sometimes able to avoid identified triggers for their asthma. Of those who stated that they had been prescribed controller medications, 116 of 332 (35%) stated that they did not use the controller medication on a daily basis. The Asthma APGAR system and the ACT™/CACT™ similarly assess asthma control in a multicenter primary care-based sample. The Asthma APGAR system identified an "actionable item" in more than 75% (234) of the individuals with poor asthma control, thus linking an assessment of poor asthma control with a management strategy. Copyright © 2014 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  6. Strategies for recruiting representative samples of Asian Americans for a population-based case-control study.

    PubMed

    Wong, Celeste K; Horn-Ross, Pamela L; Gee, Gilbert C; Shariff-Marco, Salma; Quach, Thu; Allen, Laura; Bautista, Roxanna; La Chica, Patricia Quema; Tseng, Winston; Chang, Pancho; Clarke, Christina A; Yang, Juan; Le, Gem M; Canchola, Alison; Irwin, Melinda L; Lee, Sandra Soo-Jin; Gomez, Scarlett Lin

    2016-10-01

    Data are limited on effective methods for recruiting persons, especially from ethnically diverse populations, into population-based studies. The goal of this study was to evaluate the variation among and representativeness of controls identified using multiple methods for a population-based case-control study of breast cancer among Asian Americans, Native Hawaiians and Pacific Islanders (AANHPIs) in the San Francisco Bay Area. We used a unique combination of targeted recruitment strategies, including address-based sampling, community-based methods, and internet-based and media-based approaches for recruiting controls, frequency matched on age and ethnicity to a population-based sample of cases. To characterise the participating controls, we compared the distribution of sociodemographic characteristics and cancer risk factors between recruitment sources using χ(2) tests. To ensure that the controls we recruited were representative of the underlying at-risk population, we compared characteristics of the controls, by ethnicity and in aggregate, to data from the California Health Interview Survey (CHIS), and adjusted the relative mix of recruitment strategies throughout the study as needed to achieve representativeness. As expected, controls (n=483) recruited by any single method were not representative. However, when aggregated across methods, controls were largely representative of the underlying source population, as characterised by CHIS, with regard to the characteristics under study, including nativity, education, marital status and body mass index. A multimode approach using targeted recruitment strategies is an effective and feasible alternative to using a single recruitment method in identifying a representative, diverse control sample for population-based studies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  7. Main Risk Factors for Ectopic Pregnancy: A Case-Control Study in A Sample of Iranian Women

    PubMed Central

    Parashi, Shayesteh; Moukhah, Somayeh; Ashrafi, Mahnaz

    2014-01-01

    Background Although the risk factors of ectopic pregnancy have been determined in previous studies, the main risk factors of ectopic pregnancy are different in various countries due to different cultural and social characteristics. Determination of main risk factors of ectopic pregnancy leads to a rapid diagnosis and an improvement in strategies for its prevention. The purpose of this study was to determine the main risk factors of ectopic pregnancy in a sample of Iranian women. Materials and Methods We designed a case-control study to include 150 cases and 300 controls and to compare them by the following factors: socio-demographic characteristics, contraceptive methods, prior tubal surgery, tubal pathology, prior ectopic pregnancy, prior caesarean section, prior abortion, prior infertility, and prior abdominal/pelvic surgery. Results The case and control groups were significantly similar in term of education and parity. There was an association between ectopic pregnancy and age which was disappeared after controlling for the main risk factors (adjusted OR=2.45, 95% CI: 0.86-6.97). There was no statistically significant relation between ectopic pregnancy and prior tubal surgery, tubal pathology, prior abortion, prior infertility, assisted reproductive technology, and oral contraceptive method (p>0.05). However, there was a significant association between prior ectopic pregnancy, prior tubal ligation, use of intrauterine device, and prior abdominal/pelvic surgery with ectopic pregnancy (p<0.05). The risk of ectopic pregnancy increased with the use of intrauterine device and tubal ligation, whereas decreased with use of oral contraception. Conclusion This study identified prior ectopic pregnancy, prior tubal ligation, use of intrauterine device, and prior pelvic/abdominal surgery as the main risk factors for ectopic pregnancy in a sample of Iranian women. Our findings can be useful for early diagnosis of ectopic pregnancy and for improvement in strategies of its

  8. 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

  9. Location in the right hemi-colon is an independent risk factor for delayed post-polypectomy hemorrhage: a multi-center case-control study.

    PubMed

    Buddingh, K Tim; Herngreen, Thomas; Haringsma, Jelle; van der Zwet, Wil C; Vleggaar, Frank P; Breumelhof, Ronald; Ter Borg, Frank

    2011-06-01

    Delayed hemorrhage is an infrequent, but serious complication of colonoscopic polypectomy. Large size is the only polyp-related factor that has been unequivocally proven to increase the risk of delayed bleeding. It has been suggested that location in the right hemi-colon is also a risk factor. The objective of this study was to determine whether polyp location is an independent risk factor for delayed post-polypectomy hemorrhage. A retrospective case-control study was conducted in two university hospitals and two community hospitals. Thirty-nine cases and 117 controls were identified. In multivariate analysis, size and location were found to be independent polyp-related risk factors for delayed type hemorrhage. The risk increased by 13% for every 1 mm increase in polyp diameter (odds ratio (OR) 1.13, 95% confidence interval (CI) 1.05-1.20, P<0.001). Polyps located in the right hemi-colon had an OR of 4.67 (1.88-11.61, P=0.001) for delayed hemorrhage. Polyps in the cecum seemed to be especially at high risk in univariate analysis (OR 13.82, 95% CI 2.66-71.73), but this could not be assessed in multivariate analysis as the number of cases was too small. Polyp type (sessile or pedunculated) was not a risk factor. Polyp location in the right hemi-colon seems to be an independent and substantial risk factor for delayed post-polypectomy hemorrhage. A low threshold for preventive hemostatic measures is advised when removing polyps from this region.

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

    PubMed

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

    2015-12-01

    The increasing prevalence of colistin resistance (ColR) Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (Kp) is a matter of concern because of its unfavourable impact on mortality of KPC-Kp bloodstream infections (BSI) and the shortage of alternative therapeutic options. A matched case-control-control analysis was conducted. The primary study end point was to assess risk factors for ColR KPC-Kp BSI. The secondary end point was to describe mortality and clinical characteristics of these infections. To assess risk factors for ColR, 142 patients with ColR KPC-Kp BSI were compared to two controls groups: 284 controls without infections caused by KPC-Kp (control group A) and 284 controls with colistin-susceptible (ColS) KPC-Kp BSI (control group B). In the first multivariate analysis (cases vs. group A), previous colistin therapy, previous KPC-Kp colonization, ≥3 previous hospitalizations, Charlson score ≥3 and neutropenia were found to be associated with the development of ColR KPC-Kp BSI. In the second multivariate analysis (cases vs. group B), only previous colistin therapy, previous KPC-Kp colonization and Charlson score ≥3 were associated with ColR. Overall, ColR among KPC-Kp blood isolates increased more than threefold during the 4.5-year study period, and 30-day mortality of ColR KPC-Kp BSI was as high as 51%. Strict rules for the use of colistin are mandatory to staunch the dissemination of ColR in KPC-Kp-endemic hospitals. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  11. The Karachi intracranial stenosis study (KISS) Protocol: An urban multicenter case-control investigation reporting the clinical, radiologic and biochemical associations of intracranial stenosis in Pakistan

    PubMed Central

    Kamal, Ayeesha Kamran; Taj, Fawad; Junaidi, Babar; Rasheed, Asif; Zaidi, Moazzam; Murtaza, Muhammed; Iqbal, Naved; Hashmat, Fahad; Alam, Syed Vaqas; Saleem, Uzma; Waheed, Shahan; Bansari, Lajpat; Shah, Nabi; Samuel, Maria; Yameen, Madiha; Naz, Sobia; Khan, Farrukh Shahab; Ahmed, Naveeduddin; Mahmood, Khalid; Sheikh, Niaz; Makki, Karim Ullah; Ahmed, Muhammad Masroor; Memon, Abdul Rauf; Wasay, Mohammad; Syed, Nadir Ali; Khealani, Bhojo; Frossard, Philippe M; Saleheen, Danish

    2009-01-01

    Background Intracranial stenosis is the most common cause of stroke among Asians. It has a poor prognosis with a high rate of recurrence. No effective medical or surgical treatment modality has been developed for the treatment of stroke due to intracranial stenosis. We aim to identify risk factors and biomarkers for intracranial stenosis and to develop techniques such as use of transcranial doppler to help diagnose intracranial stenosis in a cost-effective manner. Methods/Design The Karachi Intracranial Stenosis Study (KISS) is a prospective, observational, case-control study to describe the clinical features and determine the risk factors of patients with stroke due to intracranial stenosis and compare them to those with stroke due to other etiologies as well as to unaffected individuals. We plan to recruit 200 patients with stroke due to intracranial stenosis and two control groups each of 150 matched individuals. The first set of controls will include patients with ischemic stroke that is due to other atherosclerotic mechanisms specifically lacunar and cardioembolic strokes. The second group will consist of stroke free individuals. Standardized interviews will be conducted to determine demographic, medical, social, and behavioral variables along with baseline medications. Mandatory procedures for inclusion in the study are clinical confirmation of stroke by a healthcare professional within 72 hours of onset, 12 lead electrocardiogram, and neuroimaging. In addition, lipid profile, serum glucose, creatinine and HbA1C will be measured in all participants. Ancillary tests will include carotid ultrasound, transcranial doppler and magnetic resonance or computed tomography angiogram to rule out concurrent carotid disease. Echocardiogram and other additional investigations will be performed at these centers at the discretion of the regional physicians. Discussion The results of this study will help inform locally relevant clinical guidelines and effective public health

  12. 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

  13. A multi-center population-based case-control study of ovarian cancer in African-American women: the African American Cancer Epidemiology Study (AACES).

    PubMed

    Schildkraut, Joellen M; Alberg, Anthony J; Bandera, Elisa V; Barnholtz-Sloan, Jill; Bondy, Melissa; Cote, Michelle L; Funkhouser, Ellen; Peters, Edward; Schwartz, Ann G; Terry, Paul; Wallace, Kristin; Akushevich, Lucy; Wang, Frances; Crankshaw, Sydnee; Moorman, Patricia G

    2014-09-22

    Ovarian cancer (OVCA) is the leading cause of death from gynecological cancer, with poorer survival for African American (AA) women compared to whites. However, little is known about risk factors for OVCA in AA. To study the epidemiology of OVCA in this population, we started a collaborative effort in 10 sites in the US. Here we describe the study and highlight the challenges of conducting a study of a lethal disease in a minority population. The African American Cancer Epidemiology Study (AACES) is an ongoing, population-based case-control study of OVCA in AA in 10 geographic locations, aiming to recruit 850 women with invasive epithelial OVCA and 850 controls age- and geographically-matched to cases. Rapid case ascertainment and random-digit-dialing systems are in place to ascertain cases and controls, respectively. A telephone survey focuses on risk factors as well as factors of particular relevance for AAs. Food-frequency questionnaires, follow-up surveys, biospecimens and medical records are also obtained. Current accrual of 403 AA OVCA cases and 639 controls exceeds that of any existing study to date. We observed a high proportion (15%) of deceased non-responders among the cases that in part is explained by advanced stage at diagnosis. A logistic regression model did not support that socio-economic status was a factor in advanced stage at diagnosis. Most risk factor associations were in the expected direction and magnitude. High BMI was associated with ovarian cancer risk, with multivariable adjusted ORs and 95% CIs of 1.50 (0.99-2.27) for obese and 1.27 (0.85- 1.91) for morbidly obese women compared to normal/underweight women. AACES targets a rare tumor in AAs and addresses issues most relevant to this population. The importance of the study is accentuated by the high proportion of OVCA cases ascertained as deceased. Our analyses indicated that obesity, highly prevalent in this population (>60% of the cases), was associated with increased OVCA risk. While

  14. Correlates of suicide among veterans treated in primary care: case-control study of a nationally representative sample.

    PubMed

    Dobscha, Steven K; Denneson, Lauren M; Kovas, Anne E; Teo, Alan; Forsberg, Christopher W; Kaplan, Mark S; Bossarte, Robert; McFarland, Bentson H

    2014-12-01

    Veterans receiving Veterans Affairs (VA) healthcare have increased suicide risk compared to the general population. Many patients see primary care clinicians prior to suicide. Yet little is known about the correlates of suicide among patients who receive primary care treatment prior to death. Our aim was to describe characteristics of veterans who received VA primary care in the 6 months prior to suicide; and to compare these to characteristics of control patients who also received VA primary care. This was a retrospective case-control study. The investigators partnered with VA operations leaders to obtain death certificate data from 11 states for veterans who died by suicide in 2009. Cases were matched 1:2 to controls based on age, sex, and clinician. Demographic, diagnosis, and utilization data were obtained from VA's Corporate Data Warehouse. Additional clinical and psychosocial context data were collected using manual medical record review. Multivariate conditional logistic regression was used to examine associations between potential predictor variables and suicide. Two hundred and sixty-nine veteran cases were matched to 538 controls. Average subject age was 63 years; 97 % were male. Rates of mental health conditions, functional decline, sleep disturbance, suicidal ideation, and psychosocial stressors were all significantly greater in cases compared to controls. In the final model describing men in the sample, non-white race (OR = 0.51; 95 % CI = 0.27-0.98) and VA service-connected disability (OR = 0.54; 95 % CI = 0.36-0.80) were associated with decreased odds of suicide, while anxiety disorder (OR = 3.52; 95 % CI = 1.79-6.92), functional decline (OR = 2.52; 95 % CI = 1.55-4.10), depression (OR = 1.82; 95 % CI = 1.07-3.10), and endorsement of suicidal ideation (OR = 2.27; 95 % CI = 1.07-4.83) were associated with greater odds of suicide. Assessment for anxiety disorders and functional decline in addition to

  15. 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

  16. Laparoscopic surgery for colorectal cancer is safe and has survival outcomes similar to those of open surgery in elderly patients with a poor performance status: subanalysis of a large multicenter case-control study in Japan.

    PubMed

    Niitsu, Hiroaki; Hinoi, Takao; Kawaguchi, Yasuo; Ohdan, Hideki; Hasegawa, Hirotoshi; Suzuka, Ichio; Fukunaga, Yosuke; Yamaguchi, Takashi; Endo, Shungo; Tagami, Soichi; Idani, Hitoshi; Ichihara, Takao; Watanabe, Kazuteru; Watanabe, Masahiko

    2016-01-01

    It remains controversial whether open or laparoscopic surgery should be indicated for elderly patients with colorectal cancer and a poor performance status. In those patients aged 80 years or older with Eastern Cooperative Oncology Group performance status score of 2 or greater who received elective surgery for stage 0 to stage III colorectal adenocarcinoma and had no concomitant malignancies and who were enrolled in a multicenter case-control study entitled "Retrospective study of laparoscopic colorectal surgery for elderly patients" that was conducted in Japan between 2003 and 2007, background characteristics and short-term and long-term outcomes for open surgery and laparoscopic surgery were compared. Of the 398 patients included, 295 underwent open surgery and 103 underwent laparoscopic surgery. There were no significant differences in the baseline characteristics between open surgery and laparoscopic surgery patients, except for previous abdominal surgery and TNM stage. The median operation duration was shorter with open surgery (open surgery, 153 min; laparoscopic surgery, 202 min; P < 0.001), and less blood loss occurred with laparoscopic surgery (median open surgery, 109 g; median laparoscopic surgery, 30 g; P < 0.001). An operation duration of 180 min or more (odds ratio, 1.97; 95 % confidence interval, 1.17-3.37; P = 0.011) and selection of laparoscopic surgery (odds ratio, 0.41; 95 % confidence interval, 0.22-0.75; P = 0.003) were statistically significant in the multivariate analysis for postoperative morbidity. Moreover, laparoscopic surgery did not result in an inferior overall survival rate compared with open surgery (log-rank test P = 0.289, 0.278, 0.346, 0.199, for all-stage, stage 0-I, stage II, and stage III disease, respectively). Laparoscopic surgery in elderly colorectal cancer patients with a poor performance status is safe and not inferior to open surgery in terms of overall survival.

  17. Analysis of Clinical Cohort Data Using Nested Case-control and Case-cohort Sampling Designs. A Powerful and Economical Tool.

    PubMed

    Ohneberg, K; Wolkewitz, M; Beyersmann, J; Palomar-Martinez, M; Olaechea-Astigarraga, P; Alvarez-Lerma, F; Schumacher, M

    2015-01-01

    Sampling from a large cohort in order to derive a subsample that would be sufficient for statistical analysis is a frequently used method for handling large data sets in epidemiological studies with limited resources for exposure measurement. For clinical studies however, when interest is in the influence of a potential risk factor, cohort studies are often the first choice with all individuals entering the analysis. Our aim is to close the gap between epidemiological and clinical studies with respect to design and power considerations. Schoenfeld's formula for the number of events required for a Cox' proportional hazards model is fundamental. Our objective is to compare the power of analyzing the full cohort and the power of a nested case-control and a case-cohort design. We compare formulas for power for sampling designs and cohort studies. In our data example we simultaneously apply a nested case-control design with a varying number of controls matched to each case, a case cohort design with varying subcohort size, a random subsample and a full cohort analysis. For each design we calculate the standard error for estimated regression coefficients and the mean number of distinct persons, for whom covariate information is required. The formula for the power of a nested case-control design and the power of a case-cohort design is directly connected to the power of a cohort study using the well known Schoenfeld formula. The loss in precision of parameter estimates is relatively small compared to the saving in resources. Nested case-control and case-cohort studies, but not random subsamples yield an attractive alternative for analyzing clinical studies in the situation of a low event rate. Power calculations can be conducted straightforwardly to quantify the loss of power compared to the savings in the num-ber of patients using a sampling design instead of analyzing the full cohort.

  18. 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

    Baker, Kelly K; O'Reilly, Ciara E; Levine, Myron M; Kotloff, Karen L; Nataro, James P; Ayers, Tracy L; Farag, Tamer H; Nasrin, Dilruba; Blackwelder, William C; Wu, Yukun; 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

    2016-05-01

    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. 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 area near the home, soap or ash

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

    PubMed Central

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

    2016-01-01

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

  20. Automated cell counts on CSF samples: A multicenter performance evaluation of the GloCyte system.

    PubMed

    Hod, E A; Brugnara, C; Pilichowska, M; Sandhaus, L M; Luu, H S; Forest, S K; Netterwald, J C; Reynafarje, G M; Kratz, A

    2017-09-07

    Automated cell counters have replaced manual enumeration of cells in blood and most body fluids. However, due to the unreliability of automated methods at very low cell counts, most laboratories continue to perform labor-intensive manual counts on many or all cerebrospinal fluid (CSF) samples. This multicenter clinical trial investigated if the GloCyte System (Advanced Instruments, Norwood, MA), a recently FDA-approved automated cell counter, which concentrates and enumerates red blood cells (RBCs) and total nucleated cells (TNCs), is sufficiently accurate and precise at very low cell counts to replace all manual CSF counts. The GloCyte System concentrates CSF and stains RBCs with fluorochrome-labeled antibodies and TNCs with nucleic acid dyes. RBCs and TNCs are then counted by digital image analysis. Residual adult and pediatric CSF samples obtained for clinical analysis at five different medical centers were used for the study. Cell counts were performed by the manual hemocytometer method and with the GloCyte System following the same protocol at all sites. The limits of the blank, detection, and quantitation, as well as precision and accuracy of the GloCyte, were determined. The GloCyte detected as few as 1 TNC/μL and 1 RBC/μL, and reliably counted as low as 3 TNCs/μL and 2 RBCs/μL. The total coefficient of variation was less than 20%. Comparison with cell counts obtained with a hemocytometer showed good correlation (>97%) between the GloCyte and the hemocytometer, including at very low cell counts. The GloCyte instrument is a precise, accurate, and stable system to obtain red cell and nucleated cell counts in CSF samples. It allows for the automated enumeration of even very low cell numbers, which is crucial for CSF analysis. These results suggest that GloCyte is an acceptable alternative to the manual method for all CSF samples, including those with normal cell counts. © 2017 John Wiley & Sons Ltd.

  1. Type 1 diabetes risk analysis on dried blood spot samples from population-based newborns: design and feasibility of an unselected case-control study.

    PubMed

    Eising, Stefanie; Svensson, Jannet; Skogstrand, Kristin; Nilsson, Anita; Lynch, Kristian; Andersen, Paal Skytt; Lernmark, Ake; Hougaard, David M; Pociot, Flemming; Nørgaard-Pedersen, Bent; Nerup, Jørn

    2007-11-01

    Development of type 1 diabetes mellitus (T1D) may be triggered pre- or perinatally by multiple factors. Identifying new predisposing T1D markers or combinations of markers in a large, well-characterised case-control collection may be important for future T1D prevention. The present work describes the design and feasibility of a large and unselected case-control study, which will define and evaluate prediction criteria for T1D at the time of birth. Danish registries (Biological Specimen Bank for Neonatal Screening, and the National Discharge Registry) made it possible to identify and collect dried blood spots (DBS) from newborns who later developed T1D (cases) born 1981-2002. DBS samples from 2086 cases and two matching control subjects per case were analysed for genetic and immune factors that are associated with T1D: (a) candidate genes (HLA, INS and CTLA4), (b) cytokines and inflammatory markers, (c) islet auto-antibodies (GAD65A, IA-2A). The objective of the study was to define reliable prediction tools for T1D using samples available at the time of birth. In a unique approach, the study linked a large unselected and population-based sample resource to well-ascertained clinical databases and advanced technology. It combined genetic, immunological and demographic data to develop prediction algorithms. It also provided a resource for future studies in which new genetic markers can be included as they are identified.

  2. Computing power and sample size for case-control association studies with copy number polymorphism: application of mixture-based likelihood ratio test.

    PubMed

    Kim, Wonkuk; Gordon, Derek; Sebat, Jonathan; Ye, Kenny Q; Finch, Stephen J

    2008-01-01

    Recent studies suggest that copy number polymorphisms (CNPs) may play an important role in disease susceptibility and onset. Currently, the detection of CNPs mainly depends on microarray technology. For case-control studies, conventionally, subjects are assigned to a specific CNP category based on the continuous quantitative measure produced by microarray experiments, and cases and controls are then compared using a chi-square test of independence. The purpose of this work is to specify the likelihood ratio test statistic (LRTS) for case-control sampling design based on the underlying continuous quantitative measurement, and to assess its power and relative efficiency (as compared to the chi-square test of independence on CNP counts). The sample size and power formulas of both methods are given. For the latter, the CNPs are classified using the Bayesian classification rule. The LRTS is more powerful than this chi-square test for the alternatives considered, especially alternatives in which the at-risk CNP categories have low frequencies. An example of the application of the LRTS is given for a comparison of CNP distributions in individuals of Caucasian or Taiwanese ethnicity, where the LRTS appears to be more powerful than the chi-square test, possibly due to misclassification of the most common CNP category into a less common category.

  3. 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.

  4. Application of systems biology approach identifies and validates GRB2 as a risk gene for schizophrenia in the Irish Case Control Study of Schizophrenia (ICCSS) sample.

    PubMed

    Sun, Jingchun; Wan, Chunling; Jia, Peilin; Fanous, Ayman H; Kendler, Kenneth S; Riley, Brien P; Zhao, Zhongming

    2011-02-01

    Recently, we prioritized 160 schizophrenia candidate genes (SZGenes) by integrating multiple lines of evidence and subsequently identified twenty-four pathways in which these 160 genes are overrepresented. Among them, four neurotransmitter-related pathways were top ranked. In this study, we extended our previous pathway analysis by applying a systems biology approach to identifying candidate genes for schizophrenia. We constructed protein-protein interaction subnetworks for four neurotransmitter-related pathways and merged them to obtain a general neurotransmitter network, from which five candidate genes stood out. We tested the association of four genes (GRB2, HSPA5, YWHAG, and YWHAZ) in the Irish Case-Control Study of Schizophrenia (ICCSS) sample (1021 cases and 626 controls). Interestingly, six of the seven tested SNPs in GRB2 showed significant signal, two of which (rs7207618 and rs9912608) remained significant after permutation test or Bonferroni correction, suggesting that GRB2 might be a risk gene for schizophrenia in Irish population. To our knowledge, this is the first report of GRB2 being significantly associated with schizophrenia in a specific population. Our results suggest that the systems biology approach is promising for identification of candidate genes and understanding the etiology of complex diseases. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Baby knows best? The impact of weaning style on food preferences and body mass index in early childhood in a case-controlled sample.

    PubMed

    Townsend, Ellen; Pitchford, Nicola J

    2012-01-01

    The impact of different weaning methods on food preferences and body mass index (BMI) in early childhood is not known. Here, we examine if weaning method-baby-led weaning versus traditional spoon feeding-influences food preferences and health-related outcomes. Parents (n=155) recruited through the Nottingham Toddler laboratory and relevant internet sites completed a questionnaire concerning (1) infant feeding and weaning style (baby-led=92, spoon-fed=63, age range 20-78 months), (2) their child's preference for 151 foods (analysed by common food categories, eg, carbohydrates, proteins, dairy) and (3) exposure (frequency of consumption). Food preference and exposure data were analysed using a case-controlled matched sample to account for the effect of age on food preference. All other analyses were conducted with the whole sample. The primary outcome measures were food preferences, exposure and weaning style. The secondary outcome measures were BMI and picky eating. Compared to the spoon-fed group, the baby-led group demonstrated (1) significantly increased liking for carbohydrates (no other differences in preference were found) and (2) carbohydrates to be their most preferred foods (compared to sweet foods for the spoon-fed group). Preference and exposure ratings were not influenced by socially desirable responding or socioeconomic status, although an increased liking for vegetables was associated with higher social class. There was an increased incidence of (1) underweight in the baby-led group and (2) obesity in the spoon-fed group. No difference in picky eating was found between the two weaning groups. Weaning style impacts on food preferences and health in early childhood. Our results suggest that infants weaned through the baby-led approach learn to regulate their food intake in a manner, which leads to a lower BMI and a preference for healthy foods like carbohydrates. This has implications for combating the well-documented rise of obesity in contemporary

  6. 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.

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

    PubMed

    Jung, Sun-Young; Sohn, Hyun Soon; Park, Eun-Ja; Suh, Hae Sun; Park, Ji-Won; Kwon, Jin-Won

    2016-01-01

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

  8. Evaluation of Legionella Air Contamination in Healthcare Facilities by Different Sampling Methods: An Italian Multicenter Study

    PubMed Central

    Montagna, Maria Teresa; De Giglio, Osvalda; Cristina, Maria Luisa; Napoli, Christian; Pacifico, Claudia; Agodi, Antonella; Baldovin, Tatjana; Casini, Beatrice; Coniglio, Maria Anna; D’Errico, Marcello Mario; Delia, Santi Antonino; Deriu, Maria Grazia; Guida, Marco; Laganà, Pasqualina; Liguori, Giorgio; Moro, Matteo; Mura, Ida; Pennino, Francesca; Privitera, Gaetano; Romano Spica, Vincenzo; Sembeni, Silvia; Spagnolo, Anna Maria; Tardivo, Stefano; Torre, Ida; Valeriani, Federica; Albertini, Roberto; Pasquarella, Cesira

    2017-01-01

    Healthcare facilities (HF) represent an at-risk environment for legionellosis transmission occurring after inhalation of contaminated aerosols. In general, the control of water is preferred to that of air because, to date, there are no standardized sampling protocols. Legionella air contamination was investigated in the bathrooms of 11 HF by active sampling (Surface Air System and Coriolis®μ) and passive sampling using settling plates. During the 8-hour sampling, hot tap water was sampled three times. All air samples were evaluated using culture-based methods, whereas liquid samples collected using the Coriolis®μ were also analyzed by real-time PCR. Legionella presence in the air and water was then compared by sequence-based typing (SBT) methods. Air contamination was found in four HF (36.4%) by at least one of the culturable methods. The culturable investigation by Coriolis®μ did not yield Legionella in any enrolled HF. However, molecular investigation using Coriolis®μ resulted in eight HF testing positive for Legionella in the air. Comparison of Legionella air and water contamination indicated that Legionella water concentration could be predictive of its presence in the air. Furthermore, a molecular study of 12 L. pneumophila strains confirmed a match between the Legionella strains from air and water samples by SBT for three out of four HF that tested positive for Legionella by at least one of the culturable methods. Overall, our study shows that Legionella air detection cannot replace water sampling because the absence of microorganisms from the air does not necessarily represent their absence from water; nevertheless, air sampling may provide useful information for risk assessment. The liquid impingement technique appears to have the greatest capacity for collecting airborne Legionella if combined with molecular investigations. PMID:28640202

  9. Evaluation of Legionella Air Contamination in Healthcare Facilities by Different Sampling Methods: An Italian Multicenter Study.

    PubMed

    Montagna, Maria Teresa; De Giglio, Osvalda; Cristina, Maria Luisa; Napoli, Christian; Pacifico, Claudia; Agodi, Antonella; Baldovin, Tatjana; Casini, Beatrice; Coniglio, Maria Anna; D'Errico, Marcello Mario; Delia, Santi Antonino; Deriu, Maria Grazia; Guida, Marco; Laganà, Pasqualina; Liguori, Giorgio; Moro, Matteo; Mura, Ida; Pennino, Francesca; Privitera, Gaetano; Romano Spica, Vincenzo; Sembeni, Silvia; Spagnolo, Anna Maria; Tardivo, Stefano; Torre, Ida; Valeriani, Federica; Albertini, Roberto; Pasquarella, Cesira

    2017-06-22

    Healthcare facilities (HF) represent an at-risk environment for legionellosis transmission occurring after inhalation of contaminated aerosols. In general, the control of water is preferred to that of air because, to date, there are no standardized sampling protocols. Legionella air contamination was investigated in the bathrooms of 11 HF by active sampling (Surface Air System and Coriolis(®)μ) and passive sampling using settling plates. During the 8-hour sampling, hot tap water was sampled three times. All air samples were evaluated using culture-based methods, whereas liquid samples collected using the Coriolis(®)μ were also analyzed by real-time PCR. Legionella presence in the air and water was then compared by sequence-based typing (SBT) methods. Air contamination was found in four HF (36.4%) by at least one of the culturable methods. The culturable investigation by Coriolis(®)μ did not yield Legionella in any enrolled HF. However, molecular investigation using Coriolis(®)μ resulted in eight HF testing positive for Legionella in the air. Comparison of Legionella air and water contamination indicated that Legionella water concentration could be predictive of its presence in the air. Furthermore, a molecular study of 12 L. pneumophila strains confirmed a match between the Legionella strains from air and water samples by SBT for three out of four HF that tested positive for Legionella by at least one of the culturable methods. Overall, our study shows that Legionella air detection cannot replace water sampling because the absence of microorganisms from the air does not necessarily represent their absence from water; nevertheless, air sampling may provide useful information for risk assessment. The liquid impingement technique appears to have the greatest capacity for collecting airborne Legionella if combined with molecular investigations.

  10. 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.

  11. The unseen sample in cohort studies: estimation of its size and effect. Multicenter AIDS Cohort Study.

    PubMed

    Hoover, D R; Muñoz, A; Carey, V; Odaka, N; Taylor, J M; Chmiel, J S; Armstrong, J; Vermund, S H

    1991-12-01

    Recruitment of disease-free subjects into cohort studies and measurement of their time from exposure/infection to disease selectively excludes individuals (the unseen sample) who had earlier exposure and who have shorter times to disease. The unseen and observed samples may differ in other characteristics in addition to incubation period and exposure/infection time. For data with known truncation times, we develop non-parametric maximum likelihood estimates of the size, exposure/infection dates and distribution of incubation time in the unseen sample. We provide procedures to estimate and compensate for the biasing effects due to exclusion of the unseen sample in descriptive and survival analysis. We give consistency properties of these estimates and assess variability using bootstrap methods. One can use imputation to derive the above estimates from data with unknown truncation times that have been estimated parametrically. Application is made to an AIDS cohort study of over 5000 homosexual men. Important estimates obtained from this application are the annual seroconversion rates from 1978 to 1983, not otherwise obtainable in this study population.

  12. 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.

  13. Patients' bath basins as potential sources of infection: a multicenter sampling study.

    PubMed

    Johnson, Debra; Lineweaver, Lauri; Maze, Lenora M

    2009-01-01

    Nosocomial infections are a marked burden on the US health care system and are linked to a high number of patient deaths. To identify and quantify bacteria in patients' bath basins and evaluate the basins as a possible reservoir for bacterial colonization and a risk factor for subsequent hospital-acquired infection. In a prospective study at 3 acute care hospitals, 92 bath basins, including basins from 3 intensive care units, were evaluated. Sterile culture sponges were used to obtain samples from the basins. The culture sponges were sent to an outside laboratory, and qualitative and quantitative microbial tests were conducted and the results reported. Some form of bacteria grew in 98% of the samples (90 sponges), either by plating or on enrichment (95% confidence interval, 92%-99.7%). The organisms with the highest positive rates of growth on enrichment were enterococci (54%), gram-negative organisms (32%), Staphylococcus aureus (23%), vancomycin-resistant enterococci (13%), methicillin-resistant S aureus (8%), Pseudomonas aeruginosa (5%), Candida albicans (3%), and Escherichia coli (2%). Mean plate counts, in colony-forming units, were 10 187 for gram-negative organisms, 99 for E coli, 30 for P aeruginosa, 86 for S aureus, 207 for enterococci, and 31 for vancomycin-resistant enterococci. Bath basins are a reservoir for bacteria and may be a source of transmission of hospital-acquired infections. Increased awareness of bath basins as a possible source of transmission of hospital-acquired infections is needed, particularly for high-risk patients.

  14. 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

  15. Prevalence, incidence estimation, risk factors and characterization of chronic prostatitis/chronic pelvic pain syndrome in urological hospital outpatients in Italy: results of a multicenter case-control observational study.

    PubMed

    Bartoletti, Riccardo; Cai, Tommaso; Mondaini, Nicola; Dinelli, Nicola; Pinzi, Novello; Pavone, Carlo; Gontero, Paolo; Gavazzi, Andrea; Giubilei, Gianluca; Prezioso, Domenico; Mazzoli, Sandra; Boddi, Vieri; Naber, Kurt G

    2007-12-01

    We evaluated the prevalence and estimated the incidence and risk factors of chronic prostatitis/chronic pelvic pain syndrome in urological hospital outpatients in Italy. From January to June 2006 patients from 28 Italian urological centers who were between 25 and 50 years old with symptoms of chronic prostatitis/chronic pelvic pain syndrome were consecutively enrolled in this prospective epidemiological case-control study. A total of 152 subjects of similar age, race and area of origin who were investigated for infertile couples but were otherwise healthy served as controls. All subjects provided a medical history and underwent different symptom scorings, clinical evaluation and microbiological tests. Of 5,540 male urological outpatients 764 with chronic prostatitis/chronic pelvic pain syndrome were enrolled, including 225 (29.4%) at the first presentation and 539 (70.6%) who underwent previous treatment. Thus, the prevalence of the syndrome was 13.8%, while the estimated incidence was 4.5%. Cigarette smoking, a high caloric diet with low fruit and vegetable consumption, constipation, meteorism, slow digestion, a sexual relationship with more than 1 partner and coitus interruptus were more likely in patients with chronic prostatitis/chronic pelvic pain syndrome than in controls (each p <0.001). The syndrome had a negative influence on sexual desire, erectile dysfunction and premature ejaculation (p <0.001). The Meares and Stamey test was positive in 13.3% of patients and in 2.9% of controls. Urethral swabs in patients with a negative Meares and Stamey test were positive for sexually transmitted pathogens in 6%. The prevalence and estimated incidence of chronic prostatitis/chronic pelvic pain syndrome in urological hospital outpatients in Italy are high. The syndrome is closely related to lifestyle, diet, smoking, gastrointestinal or anorectal disease and impaired sexual function.

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

    PubMed

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

    2016-04-01

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

  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. 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

  19. 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.

  20. Pain catastrophizing and lower physical fitness in a sample of computer screen workers with early non-specific upper limb disorders: a case-control study.

    PubMed

    Van Eijsden-Besseling, Marjon D F; van Attekum, Antonius; de Bie, Rob A; Staal, J Bart

    2010-01-01

    In computer workers psychological factors and physical fitness may play an important role in the onset and course of non-specific work-related upper limb disorders (WRULD) beyond socio-demographic factors. Based on our experiences in daily practice we assumed that pain catastrophizing and other psychological variables such as perfectionism, anxiety state and trait, and low physical fitness, are possibly associated with the occurrence of WRULD. We aim to study the association between pain catastrophizing, perfectionism, anxiety (state and trait), physical fitness, sex and level of education and the occurrence of WRULD, controlling for age as a confounder. Eighty-eight computer workers with early non-specific WRULD, who had been recruited for an intervention study, were compared with 31 healthy computer workers (controls) recruited from different departments of a university. This cross-sectional case-control study examined the influence of aforementioned variables on WRULD by means of logistic regression analyses. Among the different predictor variables investigated, pain catastrophizing (OR=1.37; 95%CI 1.17-1.59) and lower physical fitness had a positive relationship with WRULD (OR=0.65; 95%CI 0.48-0.87). According to this study, pain catastrophizing and lower physical fitness seem to be associated with early non-specific WRULD in computer workers. Prospective studies are needed to unravel these relationships.

  1. 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

    Xu, Hongwei; Zhan, Wang; Chen, Zhiyuan

    2016-11-23

    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 AND 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.

  2. 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

  3. Comparative analysis of perioperative complications between a multicenter prospective cervical deformity database and the Nationwide Inpatient Sample database.

    PubMed

    Passias, Peter G; Horn, Samantha R; Jalai, Cyrus M; Poorman, Gregory; Bono, Olivia J; Ramchandran, Subaraman; Smith, Justin S; Scheer, Justin K; Sciubba, Daniel M; Hamilton, D Kojo; Mundis, Gregory; Oh, Cheongeun; Klineberg, Eric O; Lafage, Virginie; Shaffrey, Christopher I; Ames, Christopher P

    2017-05-17

    Complication rates for adult cervical deformity are poorly characterized given the complexity and heterogeneity of cases. To compare perioperative complication rates following adult cervical deformity corrective surgery between a prospective multicenter database for patients with cervical deformity (PCD) and the Nationwide Inpatient Sample (NIS). Retrospective review of prospective databases. A total of 11,501 adult patients with cervical deformity (11,379 patients from the NIS and 122 patients from the PCD database). Perioperative medical and surgical complications. The NIS was queried (2001-2013) for cervical deformity discharges for patients ≥18 years undergoing cervical fusions using International Classification of Disease, Ninth Revision (ICD-9) coding. Patients ≥18 years from the PCD database (2013-2015) were selected. Equivalent complications were identified and rates were compared. Bonferroni correction (p<.004) was used for Pearson chi-square. Binary logistic regression was used to evaluate differences in complication rates between databases. A total of 11,379 patients from the NIS database and 122 patiens from the PCD database were identified. Patients from the PCD database were older (62.49 vs. 55.15, p<.001) but displayed similar gender distribution. Intraoperative complication rate was higher in the PCD (39.3%) group than in the NIS (9.2%, p<.001) database. The PCD database had an increased risk of reporting overall complications than the NIS (odds ratio: 2.81, confidence interval: 1.81-4.38). Only device-related complications were greater in the NIS (7.1% vs. 1.1%, p=.007). Patients from the PCD database displayed higher rates of the following complications: peripheral vascular (0.8% vs. 0.1%, p=.001), gastrointestinal (GI) (2.5% vs. 0.2%, p<.001), infection (8.2% vs. 0.5%, p<.001), dural tear (4.1% vs. 0.6%, p<.001), and dysphagia (9.8% vs. 1.9%, p<.001). Genitourinary, wound, and deep vein thrombosis (DVT) complications were similar between

  4. 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.

  5. 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

  6. 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

  7. Case-control and within-family tests for association between 5HTTLPR and conduct problems in a longitudinal adolescent sample.

    PubMed

    Sakai, Joseph T; Lessem, Jeff M; Haberstick, Brett C; Hopfer, Christian J; Smolen, Andrew; Ehringer, Marissa A; Timberlake, David; Hewitt, John K

    2007-08-01

    Several recent studies have reported an association between the serotonin transporter 5HTTLPR (s-allele) and aggression; however, non-replications have also been reported. Inconsistencies may be explained by gene-environment interactions. Using a large general population sample, we sought to test for an association between 5HTTLPR and conduct problems, and to explore for a possible 5HTTLPR by maltreatment interaction. Using Caucasian adolescents from the genetic-pairs sample of the National Longitudinal Study of Adolescent Health (n=1,736), we tested for an association between 5HTTLPR and both a categorical and, separately, a continuous measure of conduct problems using regression analyses while controlling for sex, family effects, and age. We then tested for an association between 5HTTLPR and conduct problems using the within-family test Quantitative Transmission Disequilibrium Test. Analyses were repeated for a measure of adolescence-limited delinquency. Results did not support an association between 5HTTLPR and conduct problems or delinquency. The Quantitative Transmission Disequilibrium Test analyses, which account for population stratification, were nonsignificant (F=0.17; P=0.68); introducing maltreatment as a covariate into the model did not affect this association (F=0.17; P=0.68). No association was seen between 5HTTLPR and a measure of adolescence-limited delinquency (F=0.54; P=0.46). Using two methods in a large general population sample we did not find a significant association between 5HTTLPR and conduct problems. A gene by maltreatment interaction was not supported.

  8. 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.

  9. Clinical utility and validity of the Functional Disability Inventory (FDI) among a multicenter sample of youth with chronic pain

    PubMed Central

    Kashikar-Zuck, Susmita; Flowers, Stacy R.; Claar, Robyn Lewis; Guite, Jessica W.; Logan, Deirdre E.; Lynch-Jordan, Anne M; Palermo, Tonya M.; Wilson, Anna C.

    2011-01-01

    The Functional Disability Inventory (FDI) is a well-established and commonly used measure of physical functioning and disability in youth with chronic pain. Further validation of the measure has been called for, in particular, examination of the clinical utility and factor structure of the measure. To address this need, we utilized a large multicenter dataset of pediatric patients with chronic pain who had completed the FDI and other measures assessing pain and emotional functioning. Clinical reference points to allow for interpretation of raw scores were developed to enhance clinical utility of the measure and exploratory factor analysis was performed to examine its factor structure. Participants included 1300 youth ages 8 to 18 years (M=14.2 years; 76% female) with chronic pain. Examination of the distribution of FDI scores and validation with measures of depressive symptoms and pain intensity yielded three distinct categories of disability: No/Minimal Disability, Moderate Disability and Severe Disability. Factor analysis of FDI scores revealed a two-factor solution representing vigorous Physical Activities and non-physically strenuous Daily Activities. The three-level classification system and factor structure were further explored via comparison across the four most commonly encountered pain conditions in clinical settings (head, back, abdominal and widespread pain). Our findings provide important new information regarding the clinical utility and validity of the FDI. This will greatly enhance the interpretability of scores for research and clinical use in a wide range of pediatric pain conditions. In particular these findings will facilitate use of the FDI as an outcome measure in future clinical trials. PMID:21458162

  10. 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

  11. Importance of high IgG anti-Toxoplasma gondii titers and PCR detection of T. gondii DNA in peripheral blood samples for the diagnosis of AIDS-related cerebral toxoplasmosis: a case-control study.

    PubMed

    Vidal, José E; Diaz, Adrián Vladimir Hernández; de Oliveira, Augusto César Penalva; Dauar, Rafi Felicio; Colombo, Fabio Antonio; Pereira-Chioccola, Vera Lucia

    2011-01-01

    Cerebral toxoplasmosis (CT) continues to cause significant morbidity and mortality in human immunodeficiency virus (HIV)-infected patients in Brazil. In clinical practice, the initial diagnosis is usually presumptive and alternative diagnosis tools are necessary. Our objective was to evaluate whether the detection of high titers of IgG anti-Toxoplasma gondii and T. gondii DNA in blood samples are associated with the diagnosis of CT. In this case-control study we included 192 patients with HIV-1 infection: 64 patients with presumptive CT (cases) and 128 patients with other diseases (controls). Blood samples to perform indirect immunofluorescense reaction (IFI) to detect anti-T. gondii IgG antibodies and polymerase chain reaction (PCR) were collected before or within the first three days of anti-Toxoplasma therapy. Two multivariate logistic regression models were performed: one including the variable qualitative serology and another including quantitative serology. In the first model, positive IgG anti-T. gondii (OR 4.7, 95% CI 1.2-18.3; p = 0.027) and a positive T. gondii PCR result (OR 132, 95% CI 35-505; p < 0.001) were associated with the diagnosis. In the second model, IgG anti-T. gondii titres > 1:1024 (OR 7.6, 95% CI 2.3-25.1; p = 0.001) and a positive T. gondii PCR result (OR 147, 95% CI 35-613; p < 0.001) were associated with the diagnosis. Quantitative serology and molecular diagnosis in peripheral blood samples were independently associated with the diagnosis of CT in HIV-infected patients. These diagnostic tools can contribute to a timely diagnosis of CT in settings where Toxoplasma infection is common in the general population.

  12. Increased detection of Barrett's esophagus-associated neoplasia using wide-area trans-epithelial sampling: a multicenter, prospective, randomized trial.

    PubMed

    Vennalaganti, Prashanth R; Kaul, Vivek; Wang, Kenneth K; Falk, Gary W; Shaheen, Nicholas J; Infantolino, Anthony; Johnson, David A; Eisen, Glenn; Gerson, Lauren B; Smith, Michael S; Iyer, Prasad G; Lightdale, Charles J; Schnoll-Sussman, Felice; Gupta, Neil; Gross, Seth A; Abrams, Julian; Haber, Gregory B; Chuttani, Ram; Pleskow, Douglas K; Kothari, Shivangi; Goldblum, John R; Zhang, Yaxia; Sharma, Prateek

    2017-07-27

    Wide-area transepithelial sampling (WATS) with computer-assisted 3-dimensional analysis is a sampling technique that combines abrasive brushing of the Barrett's esophagus (BE) mucosa followed by neural network analysis to highlight abnormal-appearing cells. We performed a randomized trial of referred BE patients undergoing surveillance at 16 medical centers. Subjects received either biopsy sampling followed by WATS or WATS followed by biopsy sampling. The primary outcome was rate of detection of high-grade dysplasia/esophageal adenocarcinoma (HGD/EAC) using WATS in conjunction with biopsy sampling compared with biopsy sampling alone using standard histopathologic criteria. Secondary aims included evaluating neoplasia detection rates based on the procedure order (WATS vs biopsy sampling first), of each procedure separately, and the additional time required for WATS. One hundred sixty patients (mean age, 63.4 years; 76% men; 95% white) completed the trial. The median circumferential and maximal BE extents were 1.0 cm (interquartile range: .0-5.0) and 4.0 cm (interquartile range, 2.0-8.0), respectively. The diagnostic yield for biopsy sampling alone was as follows: HGD/EAC, 7 (4.4%); low-grade dysplasia (LGD), 28 (17.5%); nondysplastic BE (NDBE), 106 (66.25%); and no BE, 19 (11.9%). The addition of WATS to biopsy sampling yielded an additional 23 cases of HGD/EAC (absolute increase, 14.4%; 95% confidence interval, 7.5%-21.2%). Among these 23 patients, 11 were classified by biopsy sampling as NDBE and 12 as LGD/indefinite for dysplasia (IND); 14 received biopsy sampling first and 9 WATS first (not significant) and most (n = 21; 91.7%) had a prior dysplasia history. WATS added an average of 4.5 minutes to the procedure. Results of this multicenter, prospective, randomized trial demonstrate that the use of WATS in a referral BE population increases the detection of HGD/EAC. (Clinical trial registration number: NCT03008980.). Copyright © 2017. Published by Elsevier Inc.

  13. 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.

  14. 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

  15. A randomized controlled multicenter trial on the multimodal treatment of adult attention-deficit hyperactivity disorder: enrollment and characteristics of the study sample.

    PubMed

    Philipsen, Alexandra; Graf, Erika; Jans, Thomas; Matthies, Swantje; Borel, Patricia; Colla, Michael; Gentschow, Laura; Langner, Daina; Jacob, Christian; Groß-Lesch, Silke; Sobanski, Esther; Alm, Barbara; Schumacher-Stien, Martina; Roesler, Michael; Retz, Wolfgang; Retz-Junginger, Petra; Kis, Bernhard; Abdel-Hamid, Mona; Heinrich, Viola; Huss, Michael; Kornmann, Catherine; Bürger, Arne; van Elst, Ludger Tebartz; Berger, Mathias

    2014-03-01

    Adult ADHD is a frequent psychiatric disorder affecting relevant aspects of an individual's life. The aim of our study group was to carry out the first randomized controlled multicenter study to evaluate the effects of psychotherapy compared to clinical management in combination with psychopharmacological treatment with methylphenidate (MPH) or placebo (Plac) in a factorial four-arm design. Here, we present the enrollment procedure and description of adult ADHD patients recruited for the trial. Four hundred and thirty-three adult patients with ADHD were randomized at seven study sites in Germany to four treatment conditions: manualized dialectical-behavioral-therapy-based group psychotherapy (GPT) plus MPH or Plac, or clinical management (CM) including supportive counseling plus MPH or Plac with weekly sessions in the first 12 weeks and monthly sessions thereafter. Assessment for eligibility included standardized scales and instruments. After prescreening of 1,480 patients, 518 were evaluated for trial participation and 433 were randomized. The main reasons for prescreening failure were lack of interest in participating (n = 205), difficulties in meeting the time and effort requirements for participation (n = 186), and contraindications for psychopharmacological treatment with MPH (n = 194). The full analysis set (FAS) comprised 419 adult ADHD patients (mean age 35.2 years, males/females 1:1). Fifty-seven percent of the patients suffered from the combined ADHD subtype. Prevalence of at least one current or lifetime axis-I comorbidity was 66 %. Axis-II comorbidity rates was 18 % (patients with comorbid borderline and antisocial personality disorders were excluded). Our network was able to recruit an adult ADHD sample essentially comparable to community samples. A selection bias was created by excluding patients unable or unwilling to participate, or who had somatic and psychiatric contraindications for stimulant treatment (Current Controlled Trials ISRCTN54096201

  16. Agreement between factor XIII activity and antigen assays in measurement of factor XIII: A French multicenter study of 147 human plasma samples.

    PubMed

    Caron, C; Meley, R; Le Cam Duchez, V; Aillaud, M F; Lavenu-Bombled, C; Dutrillaux, F; Flaujac, C; Ryman, A; Ternisien, C; Lasne, D; Galinat, H; Pouplard, C

    2017-06-01

    Factor XIII (FXIII) deficiency is a rare hemorrhagic disorder whose early diagnosis is crucial for appropriate treatment and prophylactic supplementation in cases of severe deficiency. International guidelines recommend a quantitative FXIII activity assay as first-line screening test. FXIII antigen measurement may be performed to establish the subtype of FXIII deficiency (FXIIID) when activity is decreased. The aim of this multicenter study was to evaluate the analytical and diagnostic levels of performance of a new latex immunoassay, K-Assay(®) FXIII reagent from Stago, for first-line measurement of FXIII antigen. Results were compared to those obtained with the Berichrom(®) FXIII chromogenic assay for measurement of FXIII activity. Of the 147 patient plasma samples, 138 were selected for analysis. The accuracy was very good, with intercenter reproducibility close to 7%. Five groups were defined on FXIII activity level (<5% (n = 5), 5%-30% (n = 23), 30%-60% (n = 17), 60%-120% (n = 69), above 120% (n = 24)), without statistical differences between activity and antigen levels (P value >0.05). Correlation of the K-Assay(®) with the Berichrom(®) FXIII activity results was excellent (r = 0.919). Good agreement was established by the Bland and Altman method, with a bias of +9.4% on all samples, and of -1.4% for FXIII levels lower than 30%. One patient with afibrinogenemia showed low levels of Berichrom(®) FXIII activity but normal antigen level and clot solubility as expected. The measurement of FXIII antigen using the K-Assay(®) is a reliable first-line tool for detection of FXIII deficiency when an activity assay is not available. © 2017 John Wiley & Sons Ltd.

  17. Comparison of automated devices UX-2000 and SediMAX/AutionMax for urine samples screening: A multicenter Spanish study.

    PubMed

    Sánchez-Mora, Catalina; Acevedo, Delia; Porres, Maria Amelia; Chaqués, Ana María; Zapardiel, Javier; Gallego-Cabrera, Aurelia; López, Jose María; Maesa, Jose María

    2017-08-01

    In this study we aim to compare UX2000 (Sysmex Corp, Japan) and SediMAX/AutionMax (Arkray Factory Inc., Japan), totally automatized analyzers, against Fuchs-Rosenthal counting chamber, the gold standard technique for sediment analysis. Urine samples of 1454 patients from three Spanish hospitals were assessed for red and white blood cells (RBC; WBC) using three different techniques: flow cytometry, image-based method and Fuchs-Rosenthal counting chamber. Test strip results were subjected to concordance evaluation. Agreement was assessed by Cohen's weighted kappa for multinomial results. Sensitivity (SE) and specificity (SP) were calculated. The categorization of the results showed that UX-2000 had higher concordance over SediMAX for WBC (0.819 vs. 0.546) and similar for RBC (0.573 vs. 0.630). For RBC, UX-2000 had higher SE (92.7% vs. 80.3%) but lower SP (77.1% vs. 87.4%), and showed higher both SE (94.3% vs. 76.7%) and SP (94.7% vs. 88.2%) for WBC. Inter-devices test strip agreement was substantial (kappa>0.600) for all variables except for bilirubin (kappa: 0.598). Intra-device test strip agreement was similar for UX2000 and SediMAX with regard to RBC (kappa: 0.553 vs. 0.482) but better for UX2000 with regard to WBC (0.688 vs. 0.465). Both analyzers studied are acceptable for daily routine lab work, even though SediMAX is easier to use in laboratories thanks to its lower maintenance procedure. UX-2000 has shown to have better concordance with the gold standard method. However, it needs some improvements such as an image module in order to decrease manual microscopy review for urine samples. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  18. Cardiovascular and psychiatric morbidity in obstructive sleep apnea (OSA) with insomnia (sleep apnea plus) versus obstructive sleep apnea without insomnia: a case-control study from a Nationally Representative US sample.

    PubMed

    Gupta, Madhulika A; Knapp, Katie

    2014-01-01

    To evaluate cardiovascular and psychiatric morbidity in patient visits with obstructive sleep apnea (OSA) with insomnia (OSA+Insomnia) versus OSA without insomnia (OSA-Insomnia) in a nationally representative US sample. A retrospective case-control study of epidemiologic databases (National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey) representing an estimated ± standard error (SE) 62,253,910 ± 5,274,747 (unweighted count=7234) patient visits with diagnosis of OSA from 1995-2010, was conducted. An estimated 3,994,104 ± 791,386 (unweighted count=658) were classified as OSA+Insomnia and an estimated 58,259,806 ± 4,849,800 (unweighted count=6576) as OSA-Insomnia. Logistic regression analysis was carried out using OSA+Insomnia versus OSA-Insomnia as the dependent variable, and age (>50 years versus ≤ 50 years), sex, race ('White' versus 'non-White'), essential hypertension, heart failure, ischemic heart disease, cardiac dysrhythmia, cerebrovascular disease, diabetes, obesity, hyperlipidemia, depressive, anxiety, and adjustment disorders (includes PTSD), hypersomnia and all medications used as independent variables. All comorbidities were physician diagnosed using the ICD9-CM. Among patient visits with OSA, an estimated 6.4%± 0.9% also had insomnia. Logistic regression analysis revealed that the OSA+Insomnia group was significantly more likely to have essential hypertension (all ICD9-CM codes 401) (OR=1.83, 95% CI 1.27-2.65) and provisionally more likely to have cerebrovascular disease (ICD9-CM codes 430-438) (OR=6.58, 95% CI 1.66-26.08). The significant OR for cerebrovascular disease was considered provisional because the unweighted count was <30. In a nationally representative sample, OSA+Insomnia was associated significantly more frequently with essential hypertension than OSA-Insomnia, a finding that has not been previously reported. In contrast to studies that have considered patient self-reports of psychological

  19. The case-control design in veterinary sciences: A survey.

    PubMed

    Cullen, Jonah N; Sargeant, Jan M; Makielski, Kelly M; O'Connor, Annette M

    2016-11-01

    The case-control study design is deceptively simple. However, many design considerations influence the estimated effect measure. An investigation of case-control studies in the human health literature suggested that some of these considerations are not described in reports of case-control studies. Our hypothesis was that the majority of veterinary studies labeled as case-controls would be incident density designs, and many would not interpret the effect measure obtained from those studies as the rate ratio rather than the odds ratio. Reference databases were searched for author-designated case-control studies. A survey of 100 randomly selected studies was conducted to examine the different design options described and estimated effect measures. Of the 100 author-identified case-control studies, 83 assessed an exposure-outcome association and, of those, only 54 (65.1%) sampled the study population based on an outcome and would thus be considered case-control designs. Twelve studies were incidence density designs but none used this terminology. Of the studies that reported an odds ratio as the effect measure, none reported on additional considerations that would have enabled a more interpretable result. This survey indicated many case-control-labeled studies were not case-control designs and among case-control studies, key design aspects were not often described. The absence of information about study design elements and underlying assumptions in case-control studies limits the ability to establish the effect measured by the study and the evidentiary value of the study might be underestimated. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    PubMed

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

    2015-04-01

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

  1. 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.

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

    PubMed Central

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

    2005-01-01

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

  3. 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.

  4. Case-Control Study of Writer's Cramp

    ERIC Educational Resources Information Center

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

    2009-01-01

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

  5. 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…

  6. Case-control studies in neurosurgery.

    PubMed

    Nesvick, Cody L; Thompson, Clinton J; Boop, Frederick A; Klimo, Paul

    2014-08-01

    Observational studies, such as cohort and case-control studies, are valuable instruments in evidence-based medicine. Case-control studies, in particular, are becoming increasingly popular in the neurosurgical literature due to their low cost and relative ease of execution; however, no one has yet systematically assessed these types of studies for quality in methodology and reporting. The authors performed a literature search using PubMed/MEDLINE to identify all studies that explicitly identified themselves as "case-control" and were published in the JNS Publishing Group journals (Journal of Neurosurgery, Journal of Neurosurgery: Pediatrics, Journal of Neurosurgery: Spine, and Neurosurgical Focus) or Neurosurgery. Each paper was evaluated for 22 descriptive variables and then categorized as having either met or missed the basic definition of a case-control study. All studies that evaluated risk factors for a well-defined outcome were considered true case-control studies. The authors sought to identify key features or phrases that were or were not predictive of a true case-control study. Those papers that satisfied the definition were further evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist. The search detected 67 papers that met the inclusion criteria, of which 32 (48%) represented true case-control studies. The frequency of true case-control studies has not changed with time. Use of odds ratios (ORs) and logistic regression (LR) analysis were strong positive predictors of true case-control studies (for odds ratios, OR 15.33 and 95% CI 4.52-51.97; for logistic regression analysis, OR 8.77 and 95% CI 2.69-28.56). Conversely, negative predictors included focus on a procedure/intervention (OR 0.35, 95% CI 0.13-0.998) and use of the word "outcome" in the Results section (OR 0.23, 95% CI 0.082-0.65). After exclusion of nested case-control studies, the negative correlation between focus on a procedure

  7. Kidney function in obese adolescents with or without metabolic syndrome in a nationally-representative sample of pediatric population: First report from the Middle East and North Africa: The CASPIAN-III Study: A Case-Control Study

    PubMed Central

    Kelishadi, Roya; Gheissari, Alaleh; Bazookar, Neda; Motlagh, Mohammad Esmaeil; Taslimi, Mahnaz; Ardalan, Gelayol

    2013-01-01

    Background: Obesity in accordance with metabolic syndrome (MetS) confronts populations at the higher risk of morbidity and mortality of chronic diseases including, chronic kidney diseases (CKD). The renal complication of obesity and MetS has been less debated in young adolescents. The objective of this study was to assess the kidney function in obese adolescents with or without MetS. Materials and Methods: The data used in this study were collected as part of a national study entitled Childhood and Adolescence Surveillance and Prevention of Adult Non-communicable disease Study. The present study was conducted on a sub-sample of 113 obese adolescents (body mass index >95th percentile) aged between 10 years and 16 years selected by convenient sampling from the whole population studied. Anthropometric indexes and blood pressure were examined. A 12-h fasting serum was obtained for each participant to measure blood glucose, lipid profile, quantitative C-reactive protein (hs-CRP), Cystatin-c, urea, and creatinine. Fasting spot urine was collected to determine microalbumin and creatinine. Based on the study findings, participants were assigned into two groups with and without MetS. Results: The mean of microalbuminuria was in similar ranges in two groups and while the mean glomerular filtration rate (GFR) calculated by Bokenkamp's, updated and combined Schwartz's formulas were significantly lower in MetS + obese group in comparison with obese group. The similar result was not achieved by Filler's formula. Among MetS components, waist circumference had a correlation with hs-CRP (P = 0.04; r = 0.15). GFR was calculated based on the Schwartz formula and Cystatin-c formulas had no significant correlation with any MetS components. Conclusion: Our findings suggest that MetS can increase the risk of kidney dysfunction in obese adolescents. More studies are suggested in this regard in the pediatric population. PMID:23930111

  8. Performance of the G4 Xpert(®) MTB/RIF assay for the detection of Mycobacterium tuberculosis and rifampin resistance: a retrospective case-control study of analytical and clinical samples from high- and low-tuberculosis prevalence settings.

    PubMed

    Dharan, Nila J; Blakemore, Robert; Sloutsky, Alex; Kaur, Devinder; Alexander, Richard C; Ghajar, Minoo; Musser, Kimberlee A; Escuyer, Vincent E; Rowlinson, Marie-Claire; Crowe, Susanne; Laniado-Laborin, Rafael; Valli, Eloise; Nabeta, Pamela; Johnson, Pamela; Alland, David

    2016-12-20

    The Xpert(®) MTB/RIF (Xpert) assay is a rapid PCR-based assay for the detection of Mycobacterium tuberculosis complex DNA (MTBc) and mutations associated with rifampin resistance (RIF). An updated version introduced in 2011, the G4 Xpert, included modifications to probe B and updated analytic software. An analytical study was performed to assess Xpert detection of mutations associated with rifampin resistance in rifampin-susceptible and -resistant isolates. A clinical study was performed in which specimens from US and non-US persons suspected of tuberculosis (TB) were tested to determine Xpert performance characteristics. All specimens underwent smear microscopy, mycobacterial culture, conventional drug-susceptibility testing and Xpert testing; DNA from isolates with discordant rifampin resistance results was sequenced. Among 191 laboratory-prepared isolates in the analytical study, Xpert sensitivity for detection of rifampin resistance associated mutations was 97.7% and specificity was 90.8%, which increased to 99.0% after DNA sequencing analysis of the discordant samples. Of the 1,096 subjects in the four clinical studies, 49% were from the US. Overall, Xpert detected MTBc in 439 of 468 culture-positive specimens for a sensitivity of 93.8% (95% confidence interval [CI]: 91.2%-95.7%) and did not detect MTBc in 620 of 628 culture-negative specimens for a specificity of 98.7% (95% CI: 97.5%-99.4%). Sensitivity was 99.7% among smear-positive cases, and 76.1% among smear-negative cases. Non-determinate MTBc detection and false-positive RIF resistance results were low (1.2 and 0.9%, respectively). The updated Xpert assay retained the high sensitivity and specificity of the previous assay versions and demonstrated low rates of non-determinate and RIF resistance false positive results.

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

    PubMed

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

    2015-01-01

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

  10. 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.

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

    PubMed

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

    2014-10-01

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

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

    PubMed Central

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

    2009-01-01

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

  13. 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

  14. MassARRAY, pyrosequencing, and PNA clamping for EGFR mutation detection in lung cancer tissue and cytological samples: a multicenter study.

    PubMed

    Min, Kyueng-Whan; Kim, Wan-Seop; Jang, Se Jin; Choi, Yoo Duk; Chang, Sunhee; Jung, Soon Hee; Kim, Lucia; Roh, Mee-Sook; Lee, Choong Sik; Shim, Jung Weon; Kim, Mi Jin; Lee, Geon Kook

    2016-10-01

    Testing for epidermal growth factor receptor (EGFR) mutation is an important process in the therapeutic plan of patients with lung cancer. Recently, MassARRAY, based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, has been shown to be a useful method for somatic mutation analysis with pyrosequencing and peptide nucleic acid clamping (PNAc). A total of 107 tissues and 67 cytological samples, which were confirmed to have lung adenocarcinoma at nine hospitals in Korea, were collected. Among the MassARRAY, pyrosequencing, and PNAc, the concordance rates and sensitivity of EGFR mutation detection were analyzed and validated in comparative tissue and cytological specimens. The concordance rate between pyrosequencing and PNAc was higher than that between MassARRAY and either of the pyrosequencing and PNAc in both tissue and cytological samples. In a comparison of diagnostic performance, MassARRAY (sensitivity: 85.7 %) was higher than pyrosequencing (74.3 %) and PNAc (70 %) in tissue, although pyrosequencing (80.5 %) was more highly sensitive, compared to MassARRAY (70.7 %) and PNAc (70.7 %) in terms of cytology. Unexpectedly, use of MassARRAY resulted in a significantly different EGFR mutation detection rate between tissue and cytological samples. When used for the detection of EGFR mutations, MassARRAY was more sensitive than pyrosequencing or PNA clamping in tissue, but not in cytological samples. In EGFR mutation detection between tissues and cytology, PNAc showed relatively higher concordance than MassARRAY or pyrosequencing.

  15. 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).

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. Multicenter Patient Records Research

    PubMed Central

    Behlen, Fred M.; Johnson, Stephen 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. PMID:10579601

  1. 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

  2. Case-control studies in diabetes. Do they really use a case-control design?

    PubMed

    Ramos, Analía; Mendoza, Lilian Cristina; Rabasa, Fernanda; Bolíbar, Ignasi; Puig, Teresa; Corcoy, Rosa

    2017-07-01

    Studies defined as case-control do not always use this design. We aimed to estimate the frequency of mislabelled case-control studies in published articles in the area of diabetes and to identify the predictors of incorrect labelling. We searched Medline and Web of Science for articles with "diabetes" and "case control" in title and filtered for language (English/Romance) and period (January 2010-December 2014). Inclusion criteria were: (1) statement to use a case-control design in title, (2) to be a final full-length publication and (3) to have original data in the area of diabetes. Three independent reviewers went through titles, looked for full texts and reviewed them. Discrepancies were settled with a fourth reviewer. Expert epidemiologist advice was requested in case of doubt. case-control mislabelling; addressed predictors: publication year, journal impact factor and journal subject. proportion of mislabelled CC articles and assessment of predictors by multivariate logistic regression analysis. We retrieved 362 articles, 251 of them fulfilling inclusion criteria. The proportion of mislabelled CC studies was 43.8% (confidence interval 95% 37.7-50.0%). Most mislabelled studies had a cross-sectional design (82.7%). Predictors of mislabelling were publication year, journal impact factor and journal area. A relevant subset of studies defined as case-control in the area of diabetes correspond to mislabelled cross-sectional studies. Incorrect labelling misleads readers regarding the interpretation of results and the cause-effect hypothesis. Researchers, reviewers and editors should be aware of and commit to settle this issue.

  3. 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

  4. 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.

  5. Serotonin transporter 5HTTLPR polymorphism and affective disorders: no evidence of association in a large European multicenter study.

    PubMed

    Mendlewicz, Julien; Massat, Isabelle; Souery, Daniel; Del-Favero, Jurgen; Oruc, Lilijana; Nöthen, Markus M; Blackwood, Douglas; Muir, Walter; Battersby, Sharon; Lerer, Beny; Segman, Ronen H; Kaneva, Radka; Serretti, Alessandro; Lilli, Roberta; Lorenzi, Christian; Jakovljevic, Miro; Ivezic, Sladana; Rietschel, Marcella; Milanova, Vihra; Van Broeckhoven, Christine

    2004-05-01

    The available data from preclinical and pharmacological studies on the role of the serotonin transporter (5-HTT) support the hypothesis that a dysfunction in brain serotonergic system activity contributes to the vulnerability to affective disorders (AD). 5-HTT is the major site of serotonin reuptake into the presynaptic neuron, and it has been shown that the polymorphic repeat polymorphism in the 5-HTT promotor region (5-HTTLPR) may affect gene-transcription activity. 5-HTT maps to chromosome 17 at position 17q11.17-q12, and the 5-HTTLPR polymorphisms have been extensively investigated in AD with conflicting results. The present study tested the genetic contribution of the 5-HTTLPR polymorphism in a large European multicenter case-control sample, including 539 unipolar (UPAD), 572 bipolar patients (BPAD), and 821 controls (C). Our European collaboration has led to efforts to optimize a methodology that attenuates some of the major limitations of the case-control association approach. No association was found with primary psychiatric diagnosis (UPAD and BPAD) and with phenotypic traits (family history of AD, suicidal attempt, and presence of psychotic features). Our negative findings are not attributable to the lack of statistical power, and may contribute to clarify the role of 5-HTTLPR polymorphism in AD.

  6. AURORA: bariatric surgery registration in women of reproductive age - a multicenter prospective cohort study.

    PubMed

    Jans, Goele; Matthys, Christophe; Bel, Sarah; Ameye, Lieveke; Lannoo, Matthias; Van der Schueren, Bart; Dillemans, Bruno; Lemmens, Luc; Saey, Jean-Pierre; van Nieuwenhove, Yves; Grandjean, Pascale; De Becker, Ben; Logghe, Hilde; Coppens, Marc; Roelens, Kristien; Loccufier, Anne; Verhaeghe, Johan; Devlieger, Roland

    2016-07-29

    The expansion of the obesity epidemic is accompanied with an increase in bariatric procedures, in particular in women of reproductive age. The weight loss induced by the surgery is believed to reverse the negative impact of overweight and obesity on female reproduction, however, research is limited to in particular retrospective cohort studies and a growing number of small case-series and case-(control) studies. AURORA is a multicenter prospective cohort study. The main objective is to collect long-term data on reproductive outcomes before and after bariatric surgery and in a subsequent pregnancy. Women aged 18-45 years are invited to participate at 4 possible inclusion moments: 1) before surgery, 2) after surgery, 3) before 15 weeks of pregnancy and 4) in the immediate postpartum period (day 3-4). Depending on the time of inclusion, data are collected before surgery (T1), 3 weeks and 3, 6, 12 or x months after surgery (T2-T5) and during the first, second and third trimester of pregnancy (T6-T8), at delivery (T9) and 6 weeks and 6 months after delivery (T10-T11). Online questionnaires are send on the different measuring moments. Data are collected on contraception, menstrual cycle, sexuality, intention of becoming pregnant, diet, physical activity, lifestyle, psycho-social characteristics and dietary supplement intake. Fasting blood samples determine levels of vitamin A, D, E, K, B-1, B-12 and folate, albumin, total protein, coagulation parameters, magnesium, calcium, zinc and glucose. Participants are weighted every measuring moment. Fetal ultrasounds and pregnancy course and complications are reported every trimester of pregnancy. Breastfeeding is recorded and breast milk composition in the postpartum period is studied. AURORA is a multicenter prospective cohort study extensively monitoring women before undergoing bariatric surgery until a subsequent pregnancy and postpartum period. Retrospectively registered (July 2015 - NCT02515214 ).

  7. 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

  8. 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

  9. Early pyloric stenosis: a case control study.

    PubMed

    Demian, Marie; Nguyen, Son; Emil, Sherif

    2009-12-01

    Pyloric stenosis (PS) is rare in the first 2 weeks of life, often leading to delays in diagnosis and treatment. We conducted a case control study to delineate the characteristics of patients with early PS (EPS). In addition, we tested the hypothesis that patients with EPS present with a smaller pylorus than older patients. A database of all patients presenting with PS to a children's hospital over a 5-year period (2002-2006) was obtained. Each patient admitted during the first 2 weeks of life (subject) was matched to a patient admitted after 4 weeks of age (control), with the same gender, electrolyte status, and treating surgeon. A single pediatric radiologist, blinded to patient age, reviewed all available ultrasounds retrospectively. Demographic, clinical, diagnostic, therapeutic, and outcome data were compared. During the study period, 278 pyloromyotomies were performed for PS. Sixteen patients (5.8%) presented with EPS between 2 and 14 days of life. EPS patients had a higher prevalence of positive family history (31 vs. 0%, P = 0.043), and breast milk feeding (75 vs. 31%, P = 0.045). Sonographic measurements showed a pylorus that was of significantly less length (17.1 +/- 0.6 vs. 20.5 +/- 0.9 mm, P = 0.006) and muscle thickness (3.5 +/- 0.2 vs. 4.9 +/- 0.2 mm, P < 0.001) in patients with EPS. Hospital stay was significantly longer for EPS patients (4.3 +/- 0.9 vs. 2.0 +/- 0.1 days, P = 0.19). Babies presenting with EPS are more likely to be breast fed and to have a positive family history. EPS is associated with a longer hospital stay. Use of sonographic diagnostic measurements specific to this age group may prevent delays in diagnosis and treatment, and improve outcomes.

  10. 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

  11. Mixed Model Association with Family-Biased Case-Control Ascertainment.

    PubMed

    Hayeck, Tristan J; Loh, Po-Ru; Pollack, Samuela; Gusev, Alexander; Patterson, Nick; Zaitlen, Noah A; Price, Alkes L

    2017-01-05

    Mixed models have become the tool of choice for genetic association studies; however, standard mixed model methods may be poorly calibrated or underpowered under family sampling bias and/or case-control ascertainment. Previously, we introduced a liability threshold-based mixed model association statistic (LTMLM) to address case-control ascertainment in unrelated samples. Here, we consider family-biased case-control ascertainment, where case and control subjects are ascertained non-randomly with respect to family relatedness. Previous work has shown that this type of ascertainment can severely bias heritability estimates; we show here that it also impacts mixed model association statistics. We introduce a family-based association statistic (LT-Fam) that is robust to this problem. Similar to LTMLM, LT-Fam is computed from posterior mean liabilities (PML) under a liability threshold model; however, LT-Fam uses published narrow-sense heritability estimates to avoid the problem of biased heritability estimation, enabling correct calibration. In simulations with family-biased case-control ascertainment, LT-Fam was correctly calibrated (average χ(2) = 1.00-1.02 for null SNPs), whereas the Armitage trend test (ATT), standard mixed model association (MLM), and case-control retrospective association test (CARAT) were mis-calibrated (e.g., average χ(2) = 0.50-1.22 for MLM, 0.89-2.65 for CARAT). LT-Fam also attained higher power than other methods in some settings. In 1,259 type 2 diabetes-affected case subjects and 5,765 control subjects from the CARe cohort, downsampled to induce family-biased ascertainment, LT-Fam was correctly calibrated whereas ATT, MLM, and CARAT were again mis-calibrated. Our results highlight the importance of modeling family sampling bias in case-control datasets with related samples. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  12. 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.

  13. 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

  14. 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.

  15. 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).

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

    PubMed

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

    2014-12-01

    Nested case-control sampling is a popular design for large epidemiological cohort studies due to its cost effectiveness. A number of methods have been developed for the estimation of the proportional hazards model with nested case-control data; however, the evaluation of modeling assumption is less attended. In this article, we propose a class of goodness-of-fit test statistics for testing the proportional hazards assumption based on nested case-control data. The test statistics are constructed based on asymptotically mean-zero processes derived from Samuelsen's maximum pseudo-likelihood estimation method. In addition, we develop an innovative resampling scheme to approximate the asymptotic distribution of the test statistics while accounting for the dependent sampling scheme of nested case-control design. Numerical studies are conducted to evaluate the performance of our proposed approach, and an application to the Wilms' Tumor Study is given to illustrate the methodology. © 2014, The International Biometric Society.

  18. 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

  19. 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.

  20. 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.

  1. 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.

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

    PubMed

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

    2016-05-01

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

  3. 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

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

    PubMed

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

    2015-01-01

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

  5. 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

  6. Family-Based versus Unrelated Case-Control Designs for Genetic Associations

    PubMed Central

    Evangelou, Evangelos; Trikalinos, Thomas A; Salanti, Georgia; Ioannidis, John P. A

    2006-01-01

    The most simple and commonly used approach for genetic associations is the case-control study design of unrelated people. This design is susceptible to population stratification. This problem is obviated in family-based studies, but it is usually difficult to accumulate large enough samples of well-characterized families. We addressed empirically whether the two designs give similar estimates of association in 93 investigations where both unrelated case-control and family-based designs had been employed. Estimated odds ratios differed beyond chance between the two designs in only four instances (4%). The summary relative odds ratio (ROR) (the ratio of odds ratios obtained from unrelated case-control and family-based studies) was close to unity (0.96 [95% confidence interval, 0.91–1.01]). There was no heterogeneity in the ROR across studies (amount of heterogeneity beyond chance I2 = 0%). Differences on whether results were nominally statistically significant (p < 0.05) or not with the two designs were common (opposite classification rates 14% and 17%); this reflected largely differences in power. Conclusions were largely similar in diverse subgroup analyses. Unrelated case-control and family-based designs give overall similar estimates of association. We cannot rule out rare large biases or common small biases. PMID:16895437

  7. 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.

  8. 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.

  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. 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 below...

  11. Is intravesical instillation of hyaluronic acid and chondroitin sulfate useful in preventing recurrent bacterial cystitis? A multicenter case control analysis.

    PubMed

    Gugliotta, Giorgio; Calagna, Gloria; Adile, Giorgio; Polito, Salvatore; Saitta, Salvatore; Speciale, Patrizia; Palomba, Stefano; Perino, Antonino; Granese, Roberta; Adile, Biagio

    2015-10-01

    Urinary tract infections (UTIs) are common in the female population and, over a lifetime, about half of women have at least one episode of UTI requiring antibiotic therapy. The aim of the current study was to compare two different strategies for preventing recurrent bacterial cystitis: intravesical instillation of hyaluronic acid (HA) plus chondroitin sulfate (CS), and antibiotic prophylaxis with sulfamethoxazole plus trimethoprim. This was a retrospective review of two different cohorts of women affected by recurrent bacterial cystitis. Cases (experimental group) were women who received intravesical instillations of a sterile solution of high concentration of HA + CS in 50 mL water with calcium chloride every week during the 1(st) month and then once monthly for 4 months. The control group included women who received traditional therapy for recurrent cystitis based on daily antibiotic prophylaxis using sulfamethoxazole 200 mg plus trimethoprim 40 mg for 6 weeks. Ninety-eight and 76 patients were treated with experimental and control treatments, respectively. At 12 months after treatment, 69 and 109 UTIs were detected in the experimental and control groups, respectively. The proportion of patients free from UTIs was significantly higher in the experimental than in the control group (36.7% vs. 21.0%; p = 0.03). Experimental treatment was well tolerated and none of the patients stopped it. The intravesical instillation of HA + CS is more effective than long-term antibiotic prophylaxis for preventing recurrent bacterial cystitis. Copyright © 2015. Published by Elsevier B.V.

  12. The association between breast cancer and S100P methylation in peripheral blood by multicenter case-control studies.

    PubMed

    Yang, Rongxi; Stöcker, Sarah; Schott, Sarah; Heil, Jörg; Marme, Frederik; Cuk, Katarina; Chen, Bowang; Golatta, Michael; Zhou, Yan; Sutter, Christian; Wappenschmidt, Barbara; Schmutzler, Rita; Bugert, Peter; Qu, Bin; Bartram, Claus R; Sohn, Christof; Schneeweiss, Andreas; Burwinkel, Barbara

    2017-03-01

    Breast cancer (BC) is the leading cancer in women worldwide. Changes in DNA methylation in peripheral blood could be associated with malignant diseases. Making use of screening results by llumina 27K Methylation Assay, we validated demethylation of five CpG sites of S100P gene in blood cell DNA of BC patients by three independent retrospective studies with subjects from different centers (Validation I: 235 familial BC case and 206 controls, odds ratio per -1% methylation > 1.03, and P < 6.00 × 10-8 for all five CpG sites; Validation II: 189 sporadic BC case and 189 controls, odds ratio per -1% methylation > 1.03, P < 8.0 × 10-5 for four CpG sites; Validation III: 156 sporadic BC case and 151 controls, odds ratio per -1% methylation > 1.03, P < 6.0 × 10-4 for four CpG sites). In addition, the blood-based S100P methylation pattern was similar among BC patients with differential clinical characteristics regardless of stage, receptor status and menopause status. The observed BC-associated decreased S100P methylation in blood mainly originates from the leucocytes subpopulations but not B cells. The methylation levels of most S100P CpG sites were inversely correlated with the expression of S100P in leucocytes (P < 1.2 × 10-4) and in tissue (P < 1.1 × 10-4). This study reveals significant association between blood-based decreased S100P methylation and BC, and provides another proof for the application of altered DNA methylation signatures from blood cells as potential markers for the detection of BC, especially for the early stage. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. The effect of personal, familial, and environmental characteristics on acne vulgaris: a prospective, multicenter, case controlled study from Turkey.

    PubMed

    Karadağ, Ayşe S; Balta, İlknur; Saricaoğlu, Hayriye; Kiliç, Selim; Kelekçi, Kıymet H; Yildirim, Mehmet; Arica, Deniz A; Öztürk, Savaş; Karaman, Göksun; Çerman, Aslı A; Bilgili, Serap G; Turan, Enver; Demirci, Mustafa M; Uzunçakmak, Tuğba K; Güvenç, Serdar C; Ataseven, Arzu; Ferahbaş, Ayten; Aksoy, Berna; Çölgeçen, Emine; Ekiz, Özlem; Topaloğlu Demir, Filiz; Bilgiç, Özlem; Çakmak, Seray; Uçmak, Derya; Özuğuz, Pınar; Kaymak Konkuralp, Yeşim; Ermertcan, Aylin T; Gökdemir, Gonca; Bülbül Başkan, Emel; Alyamaç, Gökçen; Şanli, Hatice

    2017-07-11

    There are only a few studies about epidemiological features of acne vulgaris in the literature. The aim of this study was to analyze demographic, clinical, familial and environmental characteristics of acne, the role of diet and aggravating factors and association of these factors with acne severity. Patients with a diagnosis of mild-moderate to severe acne were consecutively interviewed at the participating centers during the study period. A total of 3826 patients and 759 control patients were involved in this study. Mild acne was the most common type of acne, and most of the lesions were localized on face followed by the trunk. The severity of acne was worse in patients who had a positive family history of acne. The most common triggering factor was psychological stress. We found a positive correlation with chocolate, bread, green tea, milk, white sugar, ripe banana, ice cream, apple, orange, and red meat consumption. As we compare the acne severity according to geographical features we detected mildmoderate acne was more common in Mediterrenean region and severe acne was more common in East Anatolian region. Family history positivity was more common in Aegean region and least common in Middle Anatolian region. There was statistically significant relationship as we compare acne severity and dietary factors such as chocolate, dairy products such as milk, sunflower seed consumption within the geographical regions. This study presents the demographic and clinical characteristics of acne patients in Asian and the European parts of Turkey. We believe that this study will provide a useful overview of acne in Turkey.

  14. Head trauma and Parkinson's disease: results from an Italian case-control study.

    PubMed

    Nicoletti, Alessandra; Vasta, Rosario; Mostile, Giovanni; Nicoletti, Giuseppe; Arabia, Gennarina; Iliceto, Giovanni; Lamberti, Paolo; Marconi, Roberto; Morgante, Letterio; Barone, Paolo; Quattrone, Aldo; Zappia, Mario

    2017-07-26

    We evaluated the possible association between head trauma and Parkinson's disease (PD). The FRAGAMP (Fattori di Rischio Ambientali e Genetici Associati alla Malattia di Parkinson) study is a large Italian multicenter case-control study carried out to evaluate the possible role of environmental and genetic factors in PD. Cases and controls were enrolled from six movement disorders centers located in the Central-Southern Italy. A standardized questionnaire was administered to record demographic, epidemiological, and clinical data. Positive history of head trauma was considered only if the head trauma preceded the onset of PD. All cases and controls underwent a standard neurological examination. Adjusted ORs and 95% CI were estimated using multivariate analysis (logistic regression). Four hundred ninety-two PD patients (292 men and 200 women) and 459 controls (160 men and 299 women) were enrolled in the study. A positive history for head trauma was reported by 106 (21.5%) PD patients and by 62 (13.5%) healthy controls. Multivariate analysis (OR adjusted by age, sex, family history, coffee smoking, and alcohol consumption) showed a significant positive association between PD and head trauma with an adjusted OR of 1.50 (95%CI 1.04-2.17; p value 0.03). In agreement with literature data, our study supports the positive association between head trauma and PD.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 25-hydroxyvitamin D and breast cancer, colorectal cancer, and colorectal adenomas: case-control versus nested case-control studies.

    PubMed

    Grant, William B

    2015-02-01

    Existing literature includes concerns regarding reliability of case-control studies of breast cancer incidence with respect to 25-hydroxyvitamin D (25(OH)D) concentrations. For breast cancer, only case-control studies consistently find inverse correlations between 25(OH)D and breast cancer. However, for colorectal cancer, nested case-control studies find significant inverse correlations with respect to 25(OH)D concentrations at baseline for mean follow-up times of 7 years. This is a review of results currently existing in literature. I provide evidence that 25(OH)D concentration values are only useful for short follow-up times for breast cancer since it develops rapidly. To support the robust nature of breast cancer case-control studies, I show that results from 11 studies from seven countries align in a robust power-law fit to the odds ratio versus mean 25(OH)D concentrations. Case-control studies of breast cancer incidence rates provide reliable results. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  2. Human papillomaviruses in colorectal cancers: A case-control study in western patients.

    PubMed

    Vuitton, Lucine; Jaillet, Carine; Jacquin, Elise; Monnien, Franck; Heberle, Marine; Mihai, Maria I; Lassabe, Catherine; Raffoul, Johnny; Puyraveau, Marc; Lakkis, Zaher; Lamfichekh, Najib; Picard, Alain; Prétet, Jean-Luc; Mougin, Christiane; Valmary-Degano, Séverine

    2017-04-01

    Colorectal cancer (CRC) is one of the most common cancers. As in other cancer locations, the involvement of human papillomaviruses (HPV) has been suggested but remains highly debated with wide differences among reported prevalence of HPV infection in CRCs. To determine the actual prevalence of high risk HPV16 and 18 in a large case-control study. CRC specimens were used for analysis of both tumor and distant healthy tissue. As a non-malignant control group, samples from sigmoid diverticulosis resections were studied. Detection of HPV16 and HPV18 DNA was performed using a real time polymerase chain reaction (qPCR). Ten percent of tumor samples were also randomly subjected to a complete HPV genotyping using the INNO-LiPA technique. 467 samples were analyzed: 217 tumor samples from 210 CRCs, 210 distant healthy tissue samples, and 40 sigmoid samples. HPV18 DNA was never amplified and HPV16 was amplified only three times in tumor tissues with viral loads under or at the limit of quantification. New extraction from the same tumor blocks for these samples revealed no HPV with qPCR and INNO-Lipa assays. With adequate procedures and reliable techniques, no HPV was detected in the largest case-control study so far, bringing more evidence on the absence of involvement of HPV in CRCs. Copyright © 2016 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  3. 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.

  4. Impact of preoperative immunonutrition on morbidity following cystectomy for bladder cancer: a case-control pilot study.

    PubMed

    Bertrand, J; Siegler, N; Murez, T; Poinas, G; Segui, B; Ayuso, D; Gres, P; Wagner, L; Thuret, R; Costa, P; Droupy, S

    2014-02-01

    To compare postoperative complications in patients with or without preoperative immunonutrition before cystectomy. A prospective, multicenter, pilot, case-control study was conducted during 6 months. Patients with 7-day preoperative immunonutrition were prospectively included and compared with a retrospective, matched control group without immunonutrition. Early complication rates and the length of hospital stay were analyzed. The bilateral type I error was <0.05; the power was 90%. Thirty patients in each group were required. Thirty patients were included in each group, on a comparable basis. In the immunonutrition group, fewer postoperative complications (40 vs. 76.7%; p = 0.008), less paralytic ileus at D7 (6.6 vs. 33.3%; p = 0.02), fewer infections (23.3 vs. 60%; p = 0.008), and in particular less pyelonephritis (16.7 vs. 46.7%; p = 0.03) occurred. Clavien's grades for complications were higher in the control group (p = 0.04). Mortality, pulmonary embolism, anastomotic fistulae, and wound dehiscence were similar between two groups. The length of stay was reduced by 3 days in the immunonutrition group. In this pilot case-control study, immunonutrition is associated with a decrease in postoperative complications, urinary tract infections, Clavien's grade for complications, and paralytic ileus in patients undergoing cystectomy for bladder cancer. Prospective randomized placebo control studies are needed to confirm these promising results.

  5. An alternative hypothesis testing strategy for secondary phenotype data in case-control genetic association studies.

    PubMed

    Lutz, Sharon M; Hokanson, John E; Lange, Christoph

    2014-01-01

    Motivated by the challenges associated with accounting for the ascertainment when analyzing secondary phenotypes that are correlated with case-control status, Lin and Zeng have proposed a method that properly reflects the case-control sampling (Lin and Zeng, 2009). The Lin and Zeng method has the advantage of accurately estimating effect sizes for secondary phenotypes that are normally distributed or dichotomous. This method can be computationally intensive in practice under the null hypothesis when the likelihood surface that needs to be maximized can be relatively flat. We propose an extension of the Lin and Zeng method for hypothesis testing that uses proportional odds logistic regression to circumvent these computational issues. Through simulation studies, we compare the power and type-1 error rate of our method to standard approaches and Lin and Zeng's approach.

  6. 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

  7. 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

  8. Spatial analysis of childhood cancer: a case/control study.

    PubMed

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

    2015-01-01

    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. 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. 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. 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. 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 the population; however, according to the literature

  9. 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.

  10. 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

  11. [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.

  12. 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.

  13. 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.

  14. CONTROL FUNCTION ASSISTED IPW ESTIMATION WITH A SECONDARY OUTCOME IN CASE-CONTROL STUDIES.

    PubMed

    Sofer, Tamar; Cornelis, Marilyn C; Kraft, Peter; Tchetgen Tchetgen, Eric J

    2017-04-01

    Case-control studies are designed towards studying associations between risk factors and a single, primary outcome. Information about additional, secondary outcomes is also collected, but association studies targeting such secondary outcomes should account for the case-control sampling scheme, or otherwise results may be biased. Often, one uses inverse probability weighted (IPW) estimators to estimate population effects in such studies. IPW estimators are robust, as they only require correct specification of the mean regression model of the secondary outcome on covariates, and knowledge of the disease prevalence. However, IPW estimators are inefficient relative to estimators that make additional assumptions about the data generating mechanism. We propose a class of estimators for the effect of risk factors on a secondary outcome in case-control studies that combine IPW with an additional modeling assumption: specification of the disease outcome probability model. We incorporate this model via a mean zero control function. We derive the class of all regular and asymptotically linear estimators corresponding to our modeling assumption, when the secondary outcome mean is modeled using either the identity or the log link. We find the efficient estimator in our class of estimators and show that it reduces to standard IPW when the model for the primary disease outcome is unrestricted, and is more efficient than standard IPW when the model is either parametric or semiparametric.

  15. 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

  16. 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.

  17. 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.

  18. 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.

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

    PubMed

    Borgan, Ørnulf; Keogh, Ruth

    2015-10-01

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

  20. Assessment of global phase uncertainty in case-control studies

    PubMed Central

    Uh, Hae-Won; Houwing-Duistermaat, Jeanine J; Putter, Hein; van Houwelingen, Hans C

    2009-01-01

    Background In haplotype-based candidate gene studies a problem is that the genotype data are unphased, which results in haplotype ambiguity. The measure [1] quantifies haplotype predictability from genotype data. It is computed for each individual haplotype, and for a measure of global relative efficiency a minimum value is suggested. Alternatively, we developed methods directly based on the information content of haplotype frequency estimates to obtain global relative efficiency measures: and based on A- and D-optimality, respectively. All three methods are designed for single populations; they can be applied in cases only, controls only or the whole data. Therefore they are not necessarily optimal for haplotype testing in case-control studies. Results A new global relative efficiency measure was derived to maximize power of a simple test statistic that compares haplotype frequencies in cases and controls. Application to real data showed that our proposed method gave a clear and summarizing measure for the case-control study conducted. Additionally this measure might be used for selection of individuals, who have the highest potential for improving power by resolving phase ambiguity. Conclusion Instead of using relative efficiency measure for cases only, controls only or their combined data, we link uncertainty measure to case-control studies directly. Hence, our global efficiency measure might be useful to assess whether data are informative or have enough power for estimation of a specific haplotype risk. PMID:19751505

  1. Assessment of global phase uncertainty in case-control studies.

    PubMed

    Uh, Hae-Won; Houwing-Duistermaat, Jeanine J; Putter, Hein; van Houwelingen, Hans C

    2009-09-14

    In haplotype-based candidate gene studies a problem is that the genotype data are unphased, which results in haplotype ambiguity. The R(h)(2) measure 1 quantifies haplotype predictability from genotype data. It is computed for each individual haplotype, and for a measure of global relative efficiency a minimum R(h)(2) value is suggested. Alternatively, we developed methods directly based on the information content of haplotype frequency estimates to obtain global relative efficiency measures: R(A)(2) and R(D)(2) based on A- and D-optimality, respectively. All three methods are designed for single populations; they can be applied in cases only, controls only or the whole data. Therefore they are not necessarily optimal for haplotype testing in case-control studies. A new global relative efficiency measure R(T)(2) was derived to maximize power of a simple test statistic that compares haplotype frequencies in cases and controls. Application to real data showed that our proposed method R(T)(2) gave a clear and summarizing measure for the case-control study conducted. Additionally this measure might be used for selection of individuals, who have the highest potential for improving power by resolving phase ambiguity. Instead of using relative efficiency measure for cases only, controls only or their combined data, we link uncertainty measure to case-control studies directly. Hence, our global efficiency measure might be useful to assess whether data are informative or have enough power for estimation of a specific haplotype risk.

  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. 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…

  4. Mobile phone use and brain tumours in the CERENAT case-control study.

    PubMed

    Coureau, Gaëlle; Bouvier, Ghislaine; Lebailly, Pierre; Fabbro-Peray, Pascale; Gruber, Anne; Leffondre, Karen; Guillamo, Jean-Sebastien; Loiseau, Hugues; Mathoulin-Pélissier, Simone; Salamon, Roger; Baldi, Isabelle

    2014-07-01

    The carcinogenic effect of radiofrequency electromagnetic fields in humans remains controversial. However, it has been suggested that they could be involved in the aetiology of some types of brain tumours. The objective was to analyse the association between mobile phone exposure and primary central nervous system tumours (gliomas and meningiomas) in adults. CERENAT is a multicenter case-control study carried out in four areas in France in 2004-2006. Data about mobile phone use were collected through a detailed questionnaire delivered in a face-to-face manner. Conditional logistic regression for matched sets was used to estimate adjusted ORs and 95% CIs. A total of 253 gliomas, 194 meningiomas and 892 matched controls selected from the local electoral rolls were analysed. No association with brain tumours was observed when comparing regular mobile phone users with non-users (OR=1.24; 95% CI 0.86 to 1.77 for gliomas, OR=0.90; 95% CI 0.61 to 1.34 for meningiomas). However, the positive association was statistically significant in the heaviest users when considering life-long cumulative duration (≥896 h, OR=2.89; 95% CI 1.41 to 5.93 for gliomas; OR=2.57; 95% CI 1.02 to 6.44 for meningiomas) and number of calls for gliomas (≥18,360 calls, OR=2.10, 95% CI 1.03 to 4.31). Risks were higher for gliomas, temporal tumours, occupational and urban mobile phone use. These additional data support previous findings concerning a possible association between heavy mobile phone use and brain tumours. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

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

    PubMed

    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

    2016-03-01

    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. We sought to determine if dietary salt intake is associated with pediatric-onset MS risk in a multicenter, case-control study. 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. 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 (2044mg/d) and controls (2030mg/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 100mg/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). 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. Copyright © 2016. Published by Elsevier B.V.

  6. Dietary water intake and bladder cancer risk: An Italian case-control study.

    PubMed

    Di Maso, Matteo; Bosetti, Cristina; Taborelli, Martina; Montella, Maurizio; Libra, Massimo; Zucchetto, Antonella; Turati, Federica; Parpinel, Maria; Negri, Eva; Tavani, Alessandra; Serraino, Diego; Ferraroni, Monica; La Vecchia, Carlo; Polesel, Jerry

    2016-12-01

    Previous studies on the relationship between fluid intake and risk of bladder cancer have generally focused on beverages, and results have been inconsistent. We investigated the relationship between water intake and bladder cancer risk, considering water from both beverages and foods. Between 2003 and 2014 we conducted a multicenter hospital-based case-control study in Italy on 690 cases and 665 frequency-matched controls. Water intake for beverages and foods was computed using the Italian food composition database. Odds ratios (ORs) and the corresponding 95% confidence intervals (95%CIs) for water intake were estimated by unconditional multiple logistic regression models, adjusting for major risk factors for bladder cancer. In the control group, the 64.7% of water intake derived from beverages and 35.4% from foods. Comparing the highest with the lowest quartile of intake, water from beverages (OR=1.14; 95%CI: 0.82-1.59) and water from foods (OR=0.88; 95%CI: 0.61-1.28) were not significantly associated with bladder cancer risk. Some specific water sources showed significant associations with bladder cancer risk (e.g. water from vegetables, OR=0.58; 95%CI: 0.40-0.86). However, these associations may be due to the effect of other components contained in beverages and foods rather than to the water content itself. Considering the intakes of water from both beverages and foods, total water intake was not associated with bladder cancer risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Dietary inflammatory index and non-Hodgkin lymphoma risk in an Italian case-control study.

    PubMed

    Shivappa, Nitin; Hébert, James R; Taborelli, Martina; Montella, Maurizio; Libra, Massimo; Zucchetto, Antonella; Crispo, Anna; Grimaldi, Maria; La Vecchia, Carlo; Serraino, Diego; Polesel, Jerry

    2017-07-01

    While dietary factors have been shown to play an important etiologic role in non-Hodgkin lymphoma (NHL), little is known about the association between inflammatory properties of diet and NHL risk. We explored the association between the dietary inflammatory index (DII) and NHL risk in a multicenter Italian case-control study conducted between 1999 and 2014. Cases were 536 subjects with incident, histologically confirmed NHL from three areas in Italy. Controls were 984 subjects admitted to the same network of hospitals as the cases for acute, nonmalignant conditions, unrelated to diet. DII scores were computed based on 30 nutrients and food items assessed using a reproducible and validated 78-item food-frequency questionnaire. Odds ratios (ORs) were estimated through logistic regression models adjusting for age, total energy intake, and other recognized confounding factors. Subjects in the highest quartile of DII scores (i.e., with the most pro-inflammatory diets) had a higher risk of NHL compared with subjects in the lowest quartile (i.e., with the most anti-inflammatory diets) (ORQuartile4vs1 1.61, 95% confidence interval CI 1.07-2.43; p-trend = 0.01). Stratified analyses produced stronger associations between DII and NHL among males (ORQuartile4vs1 2.14; 95% CI 1.25-3.67) with significant heterogeneity (p value = 0.02); when analyzed by histologic subtype, a significant association was observed with diffuse large B-cell lymphoma (ORQuartile4vs1 1.84; 95% CI 1.09-3.10). A pro-inflammatory diet, as indicated by higher DII scores, is associated with elevated odds of NHL, especially among males.

  8. 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

  9. 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

  10. ATRIUM: testing untyped SNPs in case-control association studies with related individuals.

    PubMed

    Wang, Zuoheng; McPeek, Mary Sara

    2009-11-01

    In genome-wide association studies, only a subset of all genomic variants are typed by current, high-throughput, SNP-genotyping platforms. However, many of the untyped variants can be well predicted from typed variants, with linkage disequilibrium (LD) information among typed and untyped variants available from an external reference panel such as HapMap. Incorporation of such external information can allow one to perform tests of association between untyped variants and phenotype, thereby making more efficient use of the available genotype data. When related individuals are included in case-control samples, the dependence among their genotypes must be properly addressed for valid association testing. In the context of testing untyped variants, an additional analytical challenge is that the dependence, across related individuals, of the partial information on untyped-SNP genotypes must also be assessed and incorporated into the analysis for valid inference. We address this challenge with ATRIUM, a method for case-control association testing with untyped SNPs, based on genome screen data in samples in which some individuals are related. ATRIUM uses LD information from an external reference panel to specify a one-degree-of-freedom test of association with an untyped SNP. It properly accounts for dependence in the partial information on untyped-SNP genotypes across related individuals. We demonstrate that ATRIUM is robust in that it maintains the nominal type I error rate even when the external reference panel is not well matched to the case-control sample. We apply the method to detect association between type 2 diabetes and variants on chromosome 10 in the Framingham SHARe data.

  11. 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.

  12. [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.

  13. Risk factors associated with lipomyelomeningocele: a case-control study.

    PubMed

    Esmaeili, Arash; Hanaei, Sara; Fadakar, Kaveh; Dadkhah, Sahar; Arjipour, Mahdi; Habibi, Zohreh; Nejat, Farideh; El Khashab, Mostafa

    2013-01-01

    In general, it seems that both genetic and environmental factors play important roles in the induction of neural tube defects. Lipomyelomeningocele (LipoMMC) is a rather common type of closed neural tube defect, but only limited studies have investigated the potential risk factors of this anomaly. Therefore, the purpose of this case-control study was to investigate the risk factors involved in LipoMMC formation. Various risk factors were evaluated in 35 children between 1 month and 10 years of age with LipoMMC in a hospital-based case-control study. The 2 control arms consisted of 35 children with myelomeningocele (MMC group) and 35 children with congenital anomalies other than central nervous system problems (control group). All groups were matched for age and visited the same hospital. A structured questionnaire was used for the collection of all data, including the mothers' weight and height during pregnancy, education, reproductive history, previous abortions, and socioeconomic status, as well as the parents' consanguinity and family history of the same anomalies. Univariate analysis of the children with LipoMMC compared to the control group showed that the use of periconceptional folic acid supplementation was significantly lower in the MMC and LipoMMC groups compared to the control group. In addition, comparison of the MMC and control groups revealed statistically significant differences regarding the use of folic acid and maternal obesity. In multivariate analysis, use of folic acid in the periconceptional period and during the first trimester was an independent risk factor for LipoMMC and MMC. Furthermore, maternal obesity was a significantly positive risk factor for MMC. The probable risk factors for LipoMMC were investigated in this case-control study. Consumption of folic acid in the periconceptional period and during the first trimester is an independent protective factor against LipoMMC. It seems that larger studies are needed to examine other possible

  14. 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

  15. 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.

  16. Sequential analysis of longitudinal data in a prospective nested case-control study.

    PubMed

    Park, Eunsik; Chang, Yuan-chin I

    2010-12-01

    The nested case-control design is a relatively new type of observational study whereby a case-control approach is employed within an established cohort. In this design, we observe cases and controls longitudinally by sampling all cases whenever they occur but controls at certain time points. Controls can be obtained at time points randomly scheduled or prefixed for operational convenience. This design with longitudinal observations is efficient in terms of cost and duration, especially when the disease is rare and the assessment of exposure levels is difficult. In our design, we propose sequential sampling methods and study both (group) sequential testing and estimation methods so that the study can be stopped as soon as the stopping rule is satisfied. To make such a longitudinal sampling more efficient in terms of both numbers of subjects and replications, we propose applying sequential sampling methods to subjects and replications, simultaneously, until the information criterion is fulfilled. This simultaneous sequential sampling on subjects and replicates is more flexible for practitioners designing their sampling schemes, and is different from the classical approaches used in longitudinal studies. We newly define the σ-field to accommodate our proposed sampling scheme, which contains mixtures of independent and correlated observations, and prove the asymptotic optimality of sequential estimation based on the martingale theories. We also prove that the independent increment structure is retained so that the group sequential method is applicable. Finally, we present results by employing sequential estimation and group sequential testing on both simulated data and real data on children's diarrhea. © 2009, The International Biometric Society.

  17. Risk factors for ovarian cancer: a case-control study.

    PubMed Central

    Booth, M.; Beral, V.; Smith, P.

    1989-01-01

    A hospital-based case-control study of ovarian cancer was conducted in London and Oxford between October 1978 and February 1983. Menstrual characteristics, reproductive and contraceptive history and history of exposure to various environmental factors were compared between 235 women with histologically diagnosed epithelial ovarian cancer and 451 controls. High gravidity, hysterectomy, female sterilisation and oral contraceptive use were associated with a reduced risk of ovarian cancer. Infertility and late age at menopause were associated with an increase in risk. While these factors were related, they were each found to be independently associated with ovarian cancer risk after adjusting for the effect of the other factors. PMID:2679848

  18. 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

  19. 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.

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

    PubMed

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

    2007-03-08

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

  1. Multilocus genetic risk score associates with ischemic stroke in case-control and prospective cohort studies.

    PubMed

    Malik, Rainer; Bevan, Steve; Nalls, Michael A; Holliday, Elizabeth G; Devan, William J; Cheng, Yu-Ching; Ibrahim-Verbaas, Carla A; Verhaaren, Benjamin F J; Bis, Joshua C; Joon, Aron Y; de Stefano, Anita L; Fornage, Myriam; Psaty, Bruce M; Ikram, M Arfan; Launer, Lenore J; van Duijn, Cornelia M; Sharma, Pankaj; Mitchell, Braxton D; Rosand, Jonathan; Meschia, James F; Levi, Christopher; Rothwell, Peter M; Sudlow, Cathie; Markus, Hugh S; Seshadri, Sudha; Dichgans, Martin

    2014-02-01

    Genome-wide association studies have revealed multiple common variants associated with known risk factors for ischemic stroke (IS). However, their aggregate effect on risk is uncertain. We aimed to generate a multilocus genetic risk score (GRS) for IS based on genome-wide association studies data from clinical-based samples and to establish its external validity in prospective population-based cohorts. Three thousand five hundred forty-eight clinic-based IS cases and 6399 controls from the Wellcome Trust Case Control Consortium 2 were used for derivation of the GRS. Subjects from the METASTROKE consortium served as a replication sample. The validation sample consisted of 22 751 participants from the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium. We selected variants that had reached genome-wide significance in previous association studies on established risk factors for IS. A combined GRS for atrial fibrillation, coronary artery disease, hypertension, and systolic blood pressure significantly associated with IS both in the case-control samples and in the prospective population-based studies. Subjects in the top quintile of the combined GRS had >2-fold increased risk of IS compared with subjects in the lowest quintile. Addition of the combined GRS to a simple model based on sex significantly improved the prediction of IS in the combined clinic-based samples but not in the population-based studies, and there was no significant improvement in net reclassification. A multilocus GRS based on common variants for established cardiovascular risk factors was significantly associated with IS both in clinic-based samples and in the general population. However, the improvement in clinical risk prediction was found to be small.

  2. Multilocus genetic risk score associates with ischemic stroke in case-control and prospective cohort studies

    PubMed Central

    Malik, R; Bevan, S; Nalls, MA; Holliday, EG; Devan, WJ; Cheng, YC; Ibrahim-Verbaas, CA; Verhaaren, BF; Bis, JC; Joon, AY; de Stefano, AL; Fornage, M; Psaty, BM; Ikram, MA; Launer, LJ; van Duijn, CM; Sharma, P; Mitchell, BD; Rosand, J; Meschia, JF; Levi, C; Rothwell, PM; Sudlow, C; Markus, HS; Seshadri, S; Dichgans, M

    2014-01-01

    BACKGROUND AND PURPOSE Genome-wide association studies have revealed multiple common variants associated with known risk factors for ischemic stroke (IS). However, their aggregate effect on risk is uncertain. We aimed to generate a multilocus genetic risk score (GRS) for IS based on genome-wide association studies data from clinical-based samples and to establish its external validity in prospective population-based cohorts. METHODS Three thousand five hundred forty-eight clinic-based IS cases and 6399 controls from the Wellcome Trust Case Control Consortium 2 were used for derivation of the GRS. Subjects from the METASTROKE consortium served as a replication sample. The validation sample consisted of 22 751 participants from the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium. We selected variants that had reached genome-wide significance in previous association studies on established risk factors for IS. RESULTS A combined GRS for atrial fibrillation, coronary artery disease, hypertension, and systolic blood pressure significantly associated with IS both in the case-control samples and in the prospective population-based studies. Subjects in the top quintile of the combined GRS had >2-fold increased risk of IS compared with subjects in the lowest quintile. Addition of the combined GRS to a simple model based on sex significantly improved the prediction of IS in the combined clinic-based samples but not in the population-based studies, and there was no significant improvement in net reclassification. CONCLUSIONS A multilocus GRS based on common variants for established cardiovascular risk factors was significantly associated with IS both in clinic-based samples and in the general population. However, the improvement in clinical risk prediction was found to be small. PMID:24436234

  3. Interlaboratory quality control of total HIV-1 DNA load measurement for multicenter reservoir studies.

    PubMed

    Gantner, Pierre; Mélard, Adeline; Damond, Florence; Delaugerre, Constance; Dina, Julia; Gueudin, Marie; Maillard, Anne; Sauné, Karine; Rodallec, Audrey; Tuaillon, Edouard; Plantier, Jean-Christophe; Rouzioux, Christine; Avettand-Fenoel, Véronique

    2017-11-01

    Viral reservoirs represent an important barrier to HIV cure. Accurate markers of HIV reservoirs are needed to develop multicenter studies. The aim of this multicenter quality control (QC) was to evaluate the inter-laboratory reproducibility of total HIV-1-DNA quantification. Ten laboratories of the ANRS-AC11 working group participated by quantifying HIV-DNA with a real-time qPCR assay (Biocentric) in four samples (QCMD). Good reproducibility was found between laboratories (standard deviation ≤ 0.2 log10 copies/10(6) PBMC) for the three positive QC that were correctly classified by each laboratory (QC1multicenter studies using this standardized assay. © 2017 Wiley Periodicals, Inc.

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. Association between migraine and asthma: matched case-control study.

    PubMed Central

    Davey, Gail; Sedgwick, Philip; Maier, Will; Visick, George; Strachan, David P; Anderson, H Ross

    2002-01-01

    BACKGROUND: Earlier studies have suggested a link between asthma and severe headache, and also between migraine and wheezing illness. Recent analysis have also shown an increase of asthma among cases with a prior history of migraine but without a history of hay fever, allergic rhinitis or eczema. AIM: To examine whether there is an association between migraine and asthma in the United Kingdom. DESIGN OF STUDY: Matched case-control study using the General Practice Research Database (GPRD). SETTING: Practices in the United Kingdom providing data on 5,110,619 patients to the GPRD. METHOD: The subjects were the patients with one or more diagnoses of migraine plus treatment for migraine. Each case was matched by general practice, sex, and age, with one control who had never been given a diagnosis of migraine. Case and control groups were compared for prevalence of asthma, chronic obstructive pulmonary disease, respiratory symptoms treated with inhalers or hay fever. Investigations were carried out to determine whether the association between migraine and asthma was stronger among patients with hayfever or those without hayfever, and whether patients with migraine had an increased prescription of other (non-migraine and non-asthma) medications. RESULTS: Among 64 678 case-control pairs, the relative risk of asthma in patients with migraine was 1.59 (95% CI = 1.54 to 1.65) among definite cases, and 0.75 (95% CI = 0.67 to 0.83) among those whose selection as case included beta-blocker prophylaxis. Among definite migraine cases, relative risks of chronic obstructive pulmonary disease, respiratory symptoms, eczema, and hay fever (pollinosis), were all raised (at 1.22, 1.85, 1.55, and 1.67, respectively). The association between migraine and asthma was stronger in patients without a diagnosis of hay fever, than in those with hayfever (relative risk = 1.32 and 1.19, respectively). The relative risk of prescription for a range of non-migraine, non-asthma medications was raised

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

    PubMed Central

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

    2015-01-01

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

  10. 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

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

    PubMed

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

    2016-05-15

    In a case-control study, matching on a disease risk score (DRS), which includes many confounders, should theoretically result in greater precision than matching on only a few confounders; however, this has not been investigated. We simulated 1,000 hypothetical cohorts with a binary exposure, a time-to-event outcome, and 13 covariates. Each cohort comprised 2 subcohorts of 10,000 patients each: a historical subcohort and a concurrent subcohort. DRS were estimated in the historical subcohorts and applied to the concurrent subcohorts. Nested case-control studies were conducted in the concurrent subcohorts using incidence density sampling with 2 strategies-matching on age and sex, with adjustment for additional confounders, and matching on DRS-followed by conditional logistic regression for 9 outcome-exposure incidence scenarios. In all scenarios, DRS matching yielded lower average standard errors and mean squared errors than did matching on age and sex. In 6 scenarios, DRS matching also resulted in greater empirical power. DRS matching resulted in less relative bias than did matching on age and sex at lower outcome incidences but more relative bias at higher incidences. Post-hoc analysis revealed that the effect of DRS model misspecification might be more pronounced at higher outcome incidences, resulting in higher relative bias. These results suggest that DRS matching might increase the statistical efficiency of case-control studies, particularly when the outcome is rare. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Nigerian juvenile offenders: a case-controlled study.

    PubMed

    Ogunlesi, A O

    1991-01-01

    A case-controlled study was carried out on all the 51 juvenile delinquents found in a point prevalence survey of a Nigerian Borstal Remand Centre. Mean age of the delinquents was 17-27 years. They were mostly from the low social class (70.6%) and the commonest reason for admission was for being beyond parental control (68.6%). Identified risk factors found for juvenile delinquency were death of biological mother, parental marital failure, growing up with relatives rather than parents, drug abuse and ordinal position in the family. Possible cultural explanations for some of these observations were proffered. The need to improve on the living conditions of these juveniles and their assessment procedure were highlighted. Finally, it is imperative that the obsolete Nigerian Children and Young Person's Law be updated.

  13. 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.

  14. 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

  15. Case-control study of respiratory cancer and employment

    SciTech Connect

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

    1984-04-01

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

  16. Risk factors for anal fistula: a case-control study.

    PubMed

    Wang, D; Yang, G; Qiu, J; Song, Y; Wang, L; Gao, J; Wang, C

    2014-07-01

    The aim of our study was to identify potential risk factors for anal fistula in order to improve prevention and treatment of anal fistula. A retrospective case-control study for anal fistula was conducted at our unit. Logistic regression analyses were carried out to identify associated risk factors for anal fistula. The final model obtained by the stepwise forward logistic regression analysis method identified the following items as independent risk factors: body mass index of >25.0 kg/m(2), high daily salt intake, history of diabetes, hyperlipidemia, dermatosis, anorectal surgery, history of smoking and alcohol intake, sedentary lifestyle, excessive intake of spicy/greasy food, very infrequent participation in sports and prolonged sitting on the toilet for defecation. Our results indicate that lifestyle factors and certain medical conditions increase an individual's risk of developing anal fistula.

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. Toxocariasis and childhood asthma: A case-control study.

    PubMed

    Cadore, Priscila Silva; Zhang, Linjie; Lemos, Liliam de Lima; Lorenzi, Carolina; Telmo, Paula de Lima; Dos Santos, Paula Costa; Mattos, Gabriela Torres; Vignol, Flávia Saraçol; Prietsch, Silvio O M; Berne, Maria Elisabeth Aires; Scaini, Carlos James

    2016-08-01

    The objective of this study is to investigate the association between anti-Toxocara IgG seropositivity and asthma in children. This was a case-control study conducted in a university hospital in south Brazil between May 2012 and June 2013. Were recruited 208 children up to 12 years old of whom 156 had asthma (cases) and 52 did not have asthma (controls), with a case-control ratio of 3:1 matched by age. Children's parents or guardians were interviewed using a structured questionnaire with closed questions. Serology was performed using enzyme-linked immunosorbent assay (ELISA) with excretory-secretory antigen of Toxocara canis (TES). The seroprevalence of IgG anti-T. canis antibodies was 12.8% in the cases and 7.7% in the controls. There was no significant association between seropositivity to T. canis and risk of asthma (adjusted odds ratio [OR]: 1.89, 95% CI: 0.52 to 6.89, p = 0.33). Household income < 2 minimum salaries, paternal school years < 9, allergic rhinitis in children, a positive family history of asthma and rhinitis and contact with cats were significantly associated with asthma, with adjusted ORs (95% CIs) of 3.05 (1.21 to 7.73), 2.83 (1.11 to 7.18), 10.5 (4.32 to 25.6), 2.65 (1.14 to 6.17), 2.49 (1.07 to 5.78) and 2.73 (1.03 to 7.27), respectively. This study did not find a statistically significant association between seropositivity to Toxocara sp. and risk of asthma in children. Low family income, low paternal education level, concomitant allergic rhinitis, family history of asthma and allergic rhinitis and contact with cats were independent factors associated with childhood asthma.

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

    PubMed Central

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

    2013-01-01

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

  3. 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

  4. Comparison of Estimates between Cohort and Case-Control Studies in Meta-Analyses of Therapeutic Interventions: A Meta-Epidemiological Study.

    PubMed

    Lanza, Amy; Ravaud, Philippe; Riveros, Carolina; Dechartres, Agnes

    2016-01-01

    Observational studies are increasingly being used for assessing therapeutic interventions. Case-control studies are generally considered to have greater risk of bias than cohort studies, but we lack evidence of differences in effect estimates between the 2 study types. We aimed to compare estimates between cohort and case-control studies in meta-analyses of observational studies of therapeutic interventions by using a meta-epidemiological study. We used a random sample of meta-analyses of therapeutic interventions published in 2013 that included both cohort and case-control studies assessing a binary outcome. For each meta-analysis, the ratio of estimates (RE) was calculated by comparing the estimate in case-control studies to that in cohort studies. Then, we used random-effects meta-analysis to estimate a combined RE across meta-analyses. An RE < 1 indicated that case-control studies yielded larger estimates than cohort studies. The final analysis included 23 meta-analyses: 138 cohort and 133 case-control studies. Treatment effect estimates did not significantly differ between case-control and cohort studies (combined RE 0.97 [95% CI 0.86-1.09]). Heterogeneity was low, with between-meta-analysis variance τ2 = 0.0049. Estimates did not differ between case-control and prospective or retrospective cohort studies (RE = 1.05 [95% CI 0.96-1.15] and RE = 0.99 [95% CI, 0.83-1.19], respectively). Sensitivity analysis of studies reporting adjusted estimates also revealed no significant difference (RE = 1.03 [95% CI 0.91-1.16]). Heterogeneity was also low for these analyses. We found no significant difference in treatment effect estimates between case-control and cohort studies assessing therapeutic interventions.

  5. Disease risk estimation by combining case-control data with aggregated information on the population at risk.

    PubMed

    Chang, Xiaohui; Waagepetersen, Rasmus; Yu, Herbert; Ma, Xiaomei; Holford, Theodore R; Wang, Rong; Guan, Yongtao

    2015-03-01

    We propose a novel statistical framework by supplementing case-control data with summary statistics on the population at risk for a subset of risk factors. Our approach is to first form two unbiased estimating equations, one based on the case-control data and the other on both the case data and the summary statistics, and then optimally combine them to derive another estimating equation to be used for the estimation. The proposed method is computationally simple and more efficient than standard approaches based on case-control data alone. We also establish asymptotic properties of the resulting estimator, and investigate its finite-sample performance through simulation. As a substantive application, we apply the proposed method to investigate risk factors for endometrial cancer, by using data from a recently completed population-based case-control study and summary statistics from the Behavioral Risk Factor Surveillance System, the Population Estimates Program of the US Census Bureau, and the Connecticut Department of Transportation. © 2014, The International Biometric Society.

  6. Differences in risk factors of malignancy between men and women with type 2 diabetes: A retrospective case-control study.

    PubMed

    Dąbrowski, Mariusz; Szymańska-Garbacz, Elektra; Miszczyszyn, Zofia; Dereziński, Tadeusz; Czupryniak, Leszek

    2017-09-15

    The aim of this multicenter, retrospective, case-control study was to identify differences in risk factors of malignancy between men and women with type 2 diabetes. Among women the most prevalent malignancies were: breast and uterine cancers (35.6% and 14.4% respectively), while among men there were: colorectal and prostate cancers (24.5% and 13.3% respectively). In both gender metformin use was associated with lower cancer risk. Obesity and insulin treatment in dose-dependent and time-varying manner were associated with significantly increased risk of malignancy in females. In men, unexpectedly, cardiovascular disease was more prevalent in control group. Other variables did not show significant association with malignancy risk. 118 women and 98 men with type 2 diabetes mellitus who developed cancer after diagnosis of diabetes and the same number of strictly age matched controls with type 2 diabetes and without malignancy were included into the study. Diabetes duration, antidiabetic medications use, glycated hemoglobin level, body mass index, smoking habits, occupation, presence of comorbidities and aspirin use were included into analyses. Metformin demonstrated protective effect against cancer in both sexes. Obesity and insulin treatment seem to have greater impact on cancer risk among women.

  7. Increased frequency of hematopoietic malignancies in relatives of patients with lymphoid neoplasms: a French case-control study

    PubMed Central

    Villeneuve, Sara; Orsi, Laurent; Monnereau, Alain; Berthou, Christian; Fenaux, Pierre; Marit, Gerald; Soubeyran, Pierre; Huguet, Françoise; Milpied, Noël; Leporrier, Michel; Hemon, Denis; Troussard, Xavier; Clavel, Jacqueline

    2009-01-01

    Lymphoid neoplasms (LN), including non-Hodgkin’s lymphoma (NHL), Hodgkin’s lymphoma (HL), lymphoproliferative syndrome (LPS) and multiple myeloma (MM), are among the most frequent cancers (approximately 17,000 new cases per year in France), after those related to smoking. LN were investigated using the data from the ENGELA study. ENGELA is a multicenter hospital-based case-control study that was carried out in France over the period September 2000 – December2004. In all, 822 cases (397 NHL, 149 LH, 168 SLP and 108 MM) and 752 controls were included and described 5481 and 5188 first degree relatives, respectively. A positive association with a familial history of hematopoietic cancer was observed for LN (OR = 1.7 [1.0–2.8]) overall and for LPS (OR = 3.2 [1.4–6.8]). The associations with HL (OR = 10.4 [2.0–53.8]) and NHL (OR = 2.4 [1.0–5.9]) were stronger for men. The associations were also stronger when the disease had been diagnosed before the relatives were aged 45 years. The results mainly support the involvement of genetic factors and suggest that at least some of those factors may be sex-linked. However, the slight overrepresentation of affected spouses among the cases might also support the responsibility of environmental factors. PMID:19058175

  8. 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.

  9. Increased Risk of Nasopharyngeal Carcinoma with Increasing Levels of Diet-Associated Inflammation in an Italian Case-Control Study.

    PubMed

    Shivappa, Nitin; Hébert, James R; Zucchetto, Antonella; Montella, Maurizio; Libra, Massimo; Garavello, Werner; Rossi, Marta; La Vecchia, Carlo; Serraino, Diego

    2016-10-01

    Components of diet can modulate inflammation and therefore may have an important role in the development of nasopharyngeal carcinoma (NPC). Little is known about the inflammatory potential of diet in relation to nasopharyngeal carcinogenesis. Data from an Italian multicenter case-control study conducted between 1992 and 2008 and including 198 cases with incident, histologically confirmed NPC, and 594 controls hospitalized for acute nonneoplastic diseases were used to estimate the relation between a dietary inflammatory index (DII) and the risk of NPC. The DII was computed based on the intake of selected dietary factors assessed by a validated 78-item food frequency questionnaire. Logistic regression models were used to estimate odds ratios (ORs) adjusted for study center, place of living, sex, age, year of interview, education, tobacco smoking, alcohol drinking, and energy intake using the residual method. Subjects with higher DII scores had an increased risk of NPC, with each DII point increasing risk by nearly 20% [OR: 1.19; 95% confidence interval (CI): 1.05-1.36]. Compared to subjects in the lowest DII tertile, those in the highest tertile had >60% higher risk of NPC (OR: 1.64; 95% CI: 1.06-2.55; Ptrend = 0.04). These results indicate that inflammatory potential of diet plays a role in NPC.

  10. [Case-control study of risk factors associated with constipation. The FREI Study].

    PubMed

    Comas Vives, A; Polanco Allué, I

    2005-04-01

    Children represent one of the patient groups most affected by constipation. Our objective was to identify and describe the risk factors associated with childhood constipation. The study had a case-control, retrospective, open and multicenter design. Clinical data on possible risk factors were collected through an ad-hoc questionnaire. Two groups were studied: children with and without constipation. Nine hundred twenty-one children were recruited; of these, 898 (97.6%) were included in the statistical analysis. There were 408 (45.4%) children in the constipated group and 490 (54.5%) in the non-constipated group. Most of the children with constipation (53.6%) had a maternal history of constipation compared with 21.4% of children without constipation (p < 0.05). More than half (53.2%) of the constipated children reported a lack of regularity in their toilet habits while 64.9 % of the children without constipation went to the toilet regularly. Toilet training started slightly earlier (at 3 years) in children without constipation (93.2%) than in those with the disorder (83.8%) (p < 0.05). At school, 57.4% of the children with constipation never used the toilet compared with 26.8% of those without constipation (p < 0.05). A total of 73.4% of children with constipation drank less than four glasses of water per day compared with 47.1% of those without constipation (p < 0.05). Consumption of vegetables and legumes in the diet was significantly lower in children with constipation than in those without (p < 0.05). The risk factors linked to childhood constipation found in this study were a familial history of constipation, irregular toilet habits, low dietary fiber contents and no fruit intake. The main preventive factors against constipation were water and vegetable consumption and training on the use of the toilet at school. Daily toilet training and dietary changes are needed to prevent constipation among children and to achieve regular defecation. This preventive

  11. 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.

  12. Risk factors of Streptococcus suis infection in Vietnam. A case-control study.

    PubMed

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

    2011-03-08

    Streptococcus suis infection, an emerging zoonosis, is an increasing public health problem across South East Asia and the most common cause of acute bacterial meningitis in adults in Vietnam. Little is known of the risk factors underlying the disease. A case-control study with appropriate hospital and matched community controls for each patient was conducted between May 2006 and June 2009. Potential risk factors were assessed using a standardized questionnaire and investigation of throat and rectal S. suis carriage in cases, controls and their pigs, using real-time PCR and culture of swab samples. We recruited 101 cases of S. suis meningitis, 303 hospital controls and 300 community controls. By multivariate analysis, risk factors identified for S. suis infection as compared to either control group included eating "high risk" dishes, including such dishes as undercooked pig blood and pig intestine (OR(1) = 2.22; 95%CI = [1.15-4.28] and OR(2) = 4.44; 95%CI = [2.15-9.15]), occupations related to pigs (OR(1) = 3.84; 95%CI = [1.32-11.11] and OR(2) = 5.52; 95%CI = [1.49-20.39]), and exposures to pigs or pork in the presence of skin injuries (OR(1) = 7.48; 95%CI = [1.97-28.44] and OR(2) = 15.96; 95%CI = [2.97-85.72]). S. suis specific DNA was detected in rectal and throat swabs of 6 patients and was cultured from 2 rectal samples, but was not detected in such samples of 1522 healthy individuals or patients without S. suis infection. This case control study, the largest prospective epidemiological assessment of this disease, has identified the most important risk factors associated with S. suis bacterial meningitis to be eating 'high risk' dishes popular in parts of Asia, occupational exposure to pigs and pig products, and preparation of pork in the presence of skin lesions. These risk factors can be addressed in public health campaigns aimed at preventing S. suis infection.

  13. 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

  14. 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.

  15. Violence against women and gastroschisis: a case-control study.

    PubMed

    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

    2013-10-17

    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. 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). 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.

  16. 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.

  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. 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. © 2016 American Society of Andrology and European Academy of Andrology.

  19. Headaches and pineal cyst: a case-control study.

    PubMed

    Seifert, Christian L; Woeller, Andreas; Valet, Michael; Zimmer, Claus; Berthele, Achim; Tölle, Thomas; Sprenger, Till

    2008-03-01

    Pineal cysts have been suggested to be linked to headache pathogenesis. However, no systematic studies on this topic have been performed so far. The aim of this study was to investigate the relationship between pineal cysts and headache and to determine the relevance of the cyst size in this context. We conducted a case-control study of patients who consulted the neurological department between 1999 and 2006 to investigate the relationship between pineal cysts and headache and to determine the relevance of the cyst size. A total of 51 patients with pineal cyst were identified, thereby 51% were suffering from headache (half of them had migraine), whereas in the control group, only 25% had headache (thereof 31% suffered from migraine). There was a significant relationship between headache (as well as migraine) and pineal cysts (chi-square test), but no significant difference in pineal cyst diameter between the patient group with headache versus without headache (t-test). Our data provide evidence for a causal relationship between pineal cysts and headache, respectively, migraine in this patient cohort.

  20. 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

  1. 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.

  2. Determinants of gestational diabetes mellitus: a case-control study.

    PubMed

    Feleke, Berhanu Elfu

    2017-07-09

    Gestational diabetes mellitus (GDM) is glucose intolerance first recognized during pregnancy. The objective of this study was to identify the determinant factors of GDM. An unmatched case-control study was conducted. Descriptive statistics were used to describe the profile of study participants and binary logistic regression was used to identify the determinants of GDM. GDM was associated with history of abortion (AOR 5.05 [95% CI: 2.65-9.63]), family history of diabetes mellitus (AOR 8.63 [95% CI: 5.19-14.35]), chronic hypertension (AOR 4.63 [95% CI: 1.27-16.86]), dietary diversification score (AOR 2.96 [95% CI: 2-4.46]), regular physical exercise (AOR 0.03 [95% CI: 0.01-0.04]), history of infertility (AOR 6.19 [95%CI: 1.86-20.16]), history of Caesarean section (AOR 3.24 [95% CI: 1.58-6.63]), previous history of GDM (AOR 8.21 [95% CI: 3.18-21.24]), previous history of intrauterine fetal death (AOR 3.96 [95% CI: 1.56-10.04]), literacy (AOR 0.6 [95% CI: 0.43-0.85]), body mass index (AOR 2.96 [95% CI: 2.08-4.2]), parity (AOR 1.78 [95% CI: 1.3-2.49]). Regular physical exercise should be used as the main tool in preventing GDM.

  3. Case-control study of a gastroschisis cluster in Nevada.

    PubMed

    Elliott, Leslie; Loomis, Dana; Lottritz, Lisa; Slotnick, Robert Nathan; Oki, Earle; Todd, Randall

    2009-11-01

    To identify potential risk factors associated with a sudden increase in gastroschisis cases in northern Nevada. Case-control study. Medical centers and a pregnancy care center in Reno, Nevada. Participants (n = 14) were women who gave birth to infants with gastroschisis at either of the 2 medical centers in Reno, Nevada, from April 5, 2007, through April 4, 2008. Controls (n = 57) were selected from the same pregnancy center providing perinatal care to the cases and were matched 4:1 to the case mothers by maternal date of birth within 1 year. Environmental exposures and illnesses during pregnancy. Association of gastroschisis with illnesses, medications, or environmental exposures. Gastroschisis was associated with the use of methamphetamine (odds ratio [OR], 7.15; 95% confidence interval [CI], 1.35-37.99) or any vasoconstrictive recreational drug (methamphetamine, amphetamine, cocaine, ecstasy) (OR, 4.46; 95% CI, 1.21-16.44) before pregnancy. When we limited self-reported illnesses to those occurring during the first trimester of pregnancy, chest colds (OR, 16.77; 95% CI, 1.88-150.27) and sore throats (OR, 12.72; 95% CI, 1.32-122.52) were associated with gastroschisis. These findings add strength to the hypothesis that use of methamphetamine and related drugs is a risk factor for gastroschisis and raise questions about the risks associated with infections.

  4. CIGARETTE SMOKING AND MALIGNANT MELANOMA: A CASE-CONTROL STUDY

    PubMed Central

    Kessides, Maria C.; Wheless, Lee; Hoffman-Bolton, Judith; Clipp, Sandra; Alani, Rhoda M.; Alberg, Anthony J.

    2010-01-01

    Background Several previous studies have reported inverse associations between cigarette smoking and melanoma. Often these studies have not adjusted for ultraviolet (UV) exposure history, skin type, or number of blistering sunburns, which could confound the observed associations between cigarette smoking and melanoma. Objective To assess whether this reported inverse association persists after adjusting for UV exposure, skin type, and number of blistering sunburns. Methods We conducted a population-based case-control study (82 melanoma cases, 164 controls). Two controls were matched to each case by age, sex, race, and skin type. Conditional logistic regression models were fit to assess the association between cigarette smoking history and melanoma, with additional adjustments for UV exposure and sunburns. Results Compared to never smokers, both former (OR 0.43, 95% CI 0.18–1.04) and current (OR 0.65, 95% CI 0.19–2.24) smoking were inversely associated with melanoma, but the associations were not statistically significant. Limitations The number of cutaneous nevi was not assessed in this study. Additionally, the relatively small number of cases limits the statistical precision of the observed associations. Conclusions After matching for age, sex, race, and skin type, and further adjusting for UV exposure and number of sunburns, cigarette smoking was not statistically significantly associated with melanoma risk, but the results were consistent with previous observations of an inverse association. PMID:20334951

  5. 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

  6. 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

  7. 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.

  8. 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: |

  9. 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.

  10. Attention-Deficit/Hyperactivity Disorder and Monetary Delay Discounting: A Meta-Analysis of Case-Control Studies

    PubMed Central

    Jackson, Jacob N S; MacKillop, James

    2016-01-01

    Background A growing number of studies have investigated delay discounting, a behavioral economic index of impulsivity, and its relevance to attention deficit hyperactivity disorder (ADHD), but with mixed findings. The current meta-analysis synthesizes the literature on the relationship between monetary delay discounting and ADHD in studies using case-control designs. Specifically, the objectives were: 1) to characterize the aggregated differences in monetary delay discounting between individuals with ADHD (cases) and controls in studies using categorical case-control designs; 2) to examine potential differences based on sample age (<18 vs. >18), reward outcome (real vs. hypothetical), and prevalence of conduct disorder and oppositional defiant disorder in the sample; and 3) to evaluate potential small-study (publication) bias in the literature. Methods From 567 candidate articles, 21 independent investigations yielded 25 case-control comparisons (total N=3,913). Random effects meta-analysis was conducted using Cohen's d as the common effect size. Publication bias was evaluated using fail-safe N, Begg-Mazumdar and Egger tests, and metaregression of publication year and effect size. Results Across studies, a statistically significant difference of medium magnitude effect size was present for the case-control comparisons (d=0.43; p < 10−15). No significant differences based on sample age, reward outcome, or comorbid status was detected. Minimal heterogeneity and evidence of publication bias was present. Conclusions These findings provide robust evidence that delay discounting is significantly elevated among individuals with ADHD compared to controls. Gaps in the literature and the importance of characterizing the neural and genetic bases of this relationship are discussed. PMID:27722208

  11. Case-Control Study of Risk Factors for Meningococcal Disease in Chile.

    PubMed

    Olea, Andrea; Matute, Isabel; González, Claudia; Delgado, Iris; Poffald, Lucy; Pedroni, Elena; Alfaro, Tania; Hirmas, Macarena; Nájera, Manuel; Gormaz, Ana; López, Darío; Loayza, Sergio; Ferreccio, Catterina; Gallegos, Doris; Fuentes, Rodrigo; Vial, Pablo; Aguilera, Ximena

    2017-07-01

    An outbreak of meningococcal disease with a case-fatality rate of 30% and caused by predominantly serogroup W of Neisseria meningitidis began in Chile in 2012. This outbreak required a case-control study to assess determinants and risk factors for infection. We identified confirmed cases during January 2012-March 2013 and selected controls by random sampling of the population, matched for age and sex, resulting in 135 case-patients and 618 controls. Sociodemographic variables, habits, and previous illnesses were studied. Analyses yielded adjusted odds ratios as estimators of the probability of disease development. Results indicated that conditions of social vulnerability, such as low income and overcrowding, as well as familial history of this disease and clinical histories, especially chronic diseases and hospitalization for respiratory conditions, increased the probability of illness. Findings should contribute to direction of intersectoral public policies toward a highly vulnerable social group to enable them to improve their living conditions and health.

  12. [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.

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

    PubMed

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

    2015-01-01

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

  14. A case-control study of pediatric falls using electronic medical records.

    PubMed

    Messmer, Patricia Ruth; Williams, Phoebe D; Williams, Arthur R

    2013-01-01

    The purpose of this study was to retrospectively review Humpty Dumpty Falls Scale (HDFS) scores using electronic medical records (EMR) reports at a pediatric hospital to determine characteristics related to falls, injuries, and performance of the HDFS tool. The specific research question was: Is there a significant difference in HDFS total scores between cases (children who fell) and controls (those who did not fall)? Results from 74 cases and 242 controls revealed the number of falls did not differ significantly between those who obtained high HDFS scores and those who obtained low scores. HDFS sensitivity was 57%, specificity was 39%. The pediatric patients who fell were mostly oriented and ambulating; falls with injury did not exceed 19%. Future case-control studies should use larger sample sizes across multiple institutions with EMR capability. © 2013 Association of Rehabilitation Nurses.

  15. 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.

  16. Benzodiazepines and hip fractures in elderly people: case-control study

    PubMed Central

    Pierfitte, Corinne; Macouillard, Gerard; Thicoïpe, Michel; Chaslerie, Anicet; Pehourcq, Fabienne; Aïssou, Myriam; Martinez, Béatrice; Lagnaoui, Rajaa; Fourrier, Annie; Bégaud, Bernard; Dangoumau, Jacques; Moore, Nicholas

    2001-01-01

    Objective To determine whether benzodiazepines are associated with an increased risk of hip fracture. Design Case-control study. Participants All incident cases of hip fracture not related to traffic accidents or cancer in patients over 65 years of age. 245 cases were matched to 817 controls. Setting Emergency department of a university hospital. Main outcome measures Exposure to benzodiazepines and other potential risk or protective factors or lifestyle items. Results The use of benzodiazepines as determined from questionnaires, medical records, or plasma samples at admission to hospital was not associated with an increased risk of hip fracture (odds ratio 0.9, 95% confidence interval 0.5 to 1.5). Hip fracture was, however, associated with the use of two or more benzodiazepines, as determined from questionnaires or medical records but not from plasma samples. Of the individual drugs, only lorazepam was significantly associated with an increased risk of hip fracture (1.8, 1.1 to 3.1). Conclusion Except for lorazepam, the presence of benzodiazepines in plasma was not associated with an increased risk of hip fracture. The method used to ascertain exposure could influence the results of case-control studies. What is already known on this topicBenzodiazepines increase the risk of elderly people falling in a dose dependent wayTheir role in hip fracture remains disputed, with increased risk sometimes attributed to drugs with a longer half life or those used to induce sleepWhat this study addsBenzodiazepines were not associated with hip fracture either as a group or according to half life or to characterisation as hypnotic or anxiolyticPatients using two or more benzodiazepines may be at higher riskPatients using lorazepam or certain other benzodiazepines may also be at a higher risk of fracture PMID:11264208

  17. Salivirus in Children and Its Association with Childhood Acute Gastroenteritis: A Paired Case-Control Study.

    PubMed

    Yu, Jie-Mei; Ao, Yuan-Yun; Liu, Na; Li, Li-Li; Duan, Zhao-Jun

    2015-01-01

    Salivirus was recently discovered in children with gastroenteritis and in sewage. Though a causative role for salivirus in childhood gastroenteritis was suggested in the previous study, the relationship between salivirus and acute gastroenteritis has not yet been clearly clarified. The sewage strain reported by Ng, although represented by incomplete genome sequencing data, was distinct from previously reported saliviruses, and had not previously been detected in humans. A case-control study examining 461 paired stool samples from children with diarrhea and healthy controls (1:1) was conducted in this study. Also, common diarrheal viruses were detected and complete genome of a salivirus was determined. Results showed that salivirus was detected in 16 (3.5%) and 13 (2.8%) of the case and control samples, respectively; no differences in detection rates (p=0.571) or mean values of viral loads (p=0.400) were observed between the groups. Multivariate Cox regression revealed no association between salivirus and gastroenteritis (p=0.774). The data also demonstrated that salivirus infection did not exacerbate clinical symptoms of gastroenteritis in children. Furthermore, complete genome sequence of a salivirus recovered from the feces of a child with diarrhea (i.e., SaliV-FHB) shared a 99% nucleotide identity with the sewage strain. In conclusion, a paired case-control study did not support a causative role for salivirus strains detected in this study with pediatric gastroenteritis. This study also demonstrated that all known saliviruses can be detected in the feces of children with or without gastroenteritis.

  18. Salivirus in Children and Its Association with Childhood Acute Gastroenteritis: A Paired Case-Control Study

    PubMed Central

    Yu, Jie-mei; Ao, Yuan-yun; Liu, Na; Li, Li-li; Duan, Zhao-jun

    2015-01-01

    Salivirus was recently discovered in children with gastroenteritis and in sewage. Though a causative role for salivirus in childhood gastroenteritis was suggested in the previous study, the relationship between salivirus and acute gastroenteritis has not yet been clearly clarified. The sewage strain reported by Ng, although represented by incomplete genome sequencing data, was distinct from previously reported saliviruses, and had not previously been detected in humans. A case-control study examining 461 paired stool samples from children with diarrhea and healthy controls (1:1) was conducted in this study. Also, common diarrheal viruses were detected and complete genome of a salivirus was determined. Results showed that salivirus was detected in 16 (3.5%) and 13 (2.8%) of the case and control samples, respectively; no differences in detection rates (p=0.571) or mean values of viral loads (p=0.400) were observed between the groups. Multivariate Cox regression revealed no association between salivirus and gastroenteritis (p=0.774). The data also demonstrated that salivirus infection did not exacerbate clinical symptoms of gastroenteritis in children. Furthermore, complete genome sequence of a salivirus recovered from the feces of a child with diarrhea (i.e., SaliV-FHB) shared a 99% nucleotide identity with the sewage strain. In conclusion, a paired case-control study did not support a causative role for salivirus strains detected in this study with pediatric gastroenteritis. This study also demonstrated that all known saliviruses can be detected in the feces of children with or without gastroenteritis. PMID:26193371

  19. Do the poor sue more? A case-control study of malpractice claims and socioeconomic status.

    PubMed

    Burstin, H R; Johnson, W G; Lipsitz, S R; Brennan, T A

    1993-10-13

    To evaluate whether socioeconomic status is associated with risk of malpractice claims, particularly among those who have suffered medical injury. Case-control study. Fifty-one hospitals in New York State. The presence and severity of medical injury, defined as disability at the time of discharge or prolongation of the hospitalization caused by medical treatment as opposed to the disease process, were assessed through review of approximately 31,000 hospital records in New York in 1984. These sampled records were then linked to formal malpractice claims. To estimate the risk of malpractice claims by age, gender, race, insurance status, and income, we conducted a case-control study of claimant cases matched with nonclaimant controls. The cases were all those patients who filed malpractice claims referring to alleged malpractice during a sampled hospitalization. Physician reviewers had previously judged the level of disability that resulted from the medical injury. Claimants (n = 51) were each matched with five nonclaimant controls on the basis of injury. Noninjured cases were matched with noninjured controls and injured cases were matched with injured controls. We found that poor patients (odds ratio [OR], 0.2; 95% confidence interval [CI], 0.03 to 0.8) and uninsured patients (OR, 0.1; 95% CI, 0.005 to 0.9) were significantly less likely to file malpractice claims, after controlling for the severity of medical injury. Among patients who suffered medical injury, the elderly (OR, 0.2; 95% CI, 0.03 to 0.9) were also less likely to file claims. Gender and race were not independently associated with risk of malpractice claims. Poor and uninsured patients are significantly less likely to sue for malpractice, even after controlling for the presence of medical injury. Fear of malpractice risk should not be a significant factor in the decision to serve the poor. Tort reforms that would protect physicians who serve the medically indigent from malpractice suits may not be

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

    PubMed

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

    2017-06-01

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

  1. Risk factors for syphilis in women: case-control study

    PubMed Central

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

    2017-01-01

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

  2. 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

  3. Zinc status in febrile seizure: a case-control study.

    PubMed

    Salehiomran, Mohammad Reza; Mahzari, Masoumeh

    2013-01-01

    Febrile seizure is the most common type of seizure in children. Their incidence is 2-5%. There are different hypotheses about relationship between neurotransmitters and trace elements (such as zinc) and febrile seizure. Zinc, as a major element of some enzymes, plays an important role in the central nervous system (CNS) and can affect some inhibitory mechanisms of CNS. The aim of the present study was to determine whether there were any changes in serum zinc level in children with febrile seizure in comparison with febrile children without seizure. This case-control study was performed on 100 patients aged 6 months to 6 years. This study was conducted between January and August 2012, on 50 children with febrile seizures (case) and 50 febrile children without seizures (control), that were referred to Amirkola Children Hospital (a referral hospital in the north of Iran). Two groups were matched for age and sex. The serum zinc levels in the both groups were determined by atomic absorption spectrophotometry method. The mean serum zinc level was 0.585±0.166 mg/L and 0.704±0.179 mg/L in the case group and the control group, respectively (p=0.001). The mean serum zinc level was significantly lower in the febrile seizure group compared to the control groups. Our findings revealed that serum zinc level was significantly lower in children with simple febrile seizure in comparison with febrile children without seizure. It can emphasize the hypothesis that there is a relation between serum zinc level and febrile seizure in children.

  4. Dermatological indicators of coronary risk: a case-control study.

    PubMed

    Mirić, D; Fabijanić, D; Giunio, L; Eterović, D; Culić, V; Bozić, I; Hozo, I

    1998-12-31

    We examined the association of dermatological signs such as baldness, thoracic hairiness, hair greying and diagonal earlobe crease with the risk of myocardial infarction in men under the age of 60 years. A hospital-based, case-control study included 842 men admitted for the first non-fatal myocardial infarction, the controls were 712 men admitted with noncardiac diagnoses, without clinical signs of coronary disease. The relative risks were estimated as odds ratios. Logistic regression was used to control for the confounding variables. Baldness, thoracic hairiness and earlobe crease were approximately 40% more prevalent in cases (P<10(-6) in each case). In both cases and controls, baldness and thoracic hairiness were frequently coexistent, as well as hair greying and earlobe crease (P<10(-4) in each case). After allowing for age and other established coronary risk factors, the relative risk of myocardial infarction for fronto-parietal baldness compared with no hair loss was 1.77 (95% CI 1.27-2.45) and it was 1.83 (95 CI 1.4-2.3) for men with thick, extended thoracic hairiness. The presence of a diagonal earlobe crease yielded a relative risk of 1.37 (95% CI 1.25-1.5), while hair greying was associated with myocardial infarction only in men under the age of 50 years. It appears that baldness, thoracic hairiness and diagonal earlobe crease indicate an additional risk of myocardial infarction in men under the age of 60 years, independently of age and other established coronary risk factors.

  5. Snow sports injuries in Scotland: a case-control study

    PubMed Central

    Langran, M; Selvaraj, S

    2002-01-01

    Objectives: To examine the incidence and patterns of snow sports injuries at the three largest commercial ski areas in Scotland and to identify factors associated with injury risk. Methods: A prospective case-control study of all injured people at Cairngorm, Glenshee, and Nevis Range ski areas during the 1999–2000 winter season. Personal details, snow sports related variables, diagnosis, and treatment were recorded. Control data were collected at random from uninjured people at all three areas. Random counts were performed to analyse the composition of the on slope population. Results: A total of 732 injuries were recorded in 674 people. Control data were collected from 336 people. The injury rate for the study was 3.7 injuries per 1000 skier days. Alpine skiers comprised 67% of the on slope population, snowboarders 26%, skiboarders 4%, and telemark skiers 2%. Lower limb injuries and sprains were the commonest injuries in alpine skiers and skiboarders. Snowboarders sustained more injuries to the upper limb and axial areas. Skiboarders and snowboarders had a higher incidence of fractures. After adjustment for other variables, three factors were all independently associated with injury: snowboarding (odds ratio (OR) 4.07, 95% confidence interval (CI) 1.65 to 10.08), alpine skiing (OR 3.82, CI 1.6 to 9.13), and age <16 years (OR 1.9, CI 1.14 to 3.17). More than five days of experience in the current season and at least one week of experience in total had a protective effect against injury. Conclusions: Despite a change in the composition of the alpine population at Scottish ski areas, the overall rate and pattern of injury are similar to those reported previously in comparable studies. Several factors are associated with an increased risk of injury and should be targeted in future injury prevention campaigns. PMID:11916898

  6. 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.

  7. 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

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

    PubMed Central

    Siener, Roswitha; Netzer, Linda; Hesse, Albrecht

    2013-01-01

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

  9. 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.

  10. [Risk factors associated with preeclampsia: case-control study].

    PubMed

    Morgan-Ortiz, Fred; Calderón-Lara, Sergio Alberto; Martínez-Félix, Jesús Israel; González-Beltrán, Aurelio; Quevedo-Castro, Everardo

    2010-03-01

    Preeclampsia is one of the most frequent and serious complication of pregnancy characterized by systemic perfusion reduction generated by vasospasm and activation of coagulation systems. To evaluate the association between preeclampsia sociodemographics and obstetrics antecedents. An unmatched case-control study was carried out in which all the clinical registries of patients with preeclampsia (cases: n = 196) assisted in the period 2003-2007 in the Hospital Civil of Culiacan, Sinaloa State of Mexico were analyzed. As controls the clinical registries of patients assisted during the same period were selected at random but that they didn't show up preeclampsia (n = 470). The association of preeclampsia with socioeconomic level, tobacco use, alcohol use, gynecologic and obstetric antecedents (sexual partners, pregnancies, deliveries and abortions number, prenatal control, contraceptive method) and previous pregnancy with preeclampsia were analyzed. There were not association between tobacco use (OR: 3.05; 95% CI: 0.81-11.48), beginning of sexual activity (p = 0.1509), number of sexual partners (OR: 1.23; 95% CI: 0.83-1.83; p = 0.3009) and sexual cohabitation less than 12 months (OR: 0.90; 95% CI: 0.63-1.27). The alcoholism (OR: 5.77; 95% CI: 1.48-22.53), socioeconomic level (p < 0.05), pregnancy previous with preeclampsia (RM:14.81; 95% CI: 1.77-123.85; p = 0.0006) were associated with preeclampsia. There were differences in the use of the contraceptive method between groups (p < 0.005). Preeclampsia was significantly associated with the alcoholism, low socioeconomic level and pregnancy previous with preeclampsia.

  11. [Risk factors associated with trigger finger. Case-control study].

    PubMed

    De la Parra-Márquez, Miguel Leonardo; Tamez-Cavazos, Roberto; Zertuche-Cedillo, Luis; Martínez-Pérez, Juan José; Velasco-Rodríguez, Víctor; Cisneros-Pérez, Vicente

    2008-01-01

    We undertook this study to identify risk factors in our population associated with trigger finger. The study was conducted at the Instituto Mexicano del Seguro Social, UMAE 21, Monterrey, Nuevo Leon, Mexico. This was a case-control, retrospective, and observational study. There were 250 patients in each group. For cases, patients who were operated on for trigger finger from March 2006 to August 2006 were included. Controls included patients admitted to the Emergency Department with hand injuries that fulfilled the selection criteria. Risk factors analyzed were diabetes, hypertension, smoking, sex, age, weight, and 19 different occupations. Mean age of the cases was 52 years (SE +/- 14.19 years) with a median and mode of 53 years. The right hand was the most common with the middle, thumb, ring, index and little fingers, respectively. A significant statistical relationship was found: females (OR 7.57, 95% CI 5.07-11.31); diabetes (OR 3.72, 95% CI 2.43-5.70); obesity (OR 1.49, 95% CI 1.02-2.19). With regard to occupation, a statistical relationship was found: homemaker (OR 2.44, 95% CI 1.62-3.69); seamstress (OR 4.8, 95% CI 1.3-21.6); and secretary (OR 2.74, 95% CI 1.38-5.52). Trigger finger is a common pathology in our population and is more frequent in women >53 years old. It may be related to diabetes, body mass index (obesity) and certain occupations such as secretary, seamstress and homemaker.

  12. Childhood trauma in multiple sclerosis: a case-control study.

    PubMed

    Spitzer, Carsten; Bouchain, Miriam; Winkler, Liza Y; Wingenfeld, Katja; Gold, Stefan M; Grabe, Hans Joergen; Barnow, Sven; Otte, Christian; Heesen, Christoph

    2012-04-01

    To investigate the association between childhood trauma and multiple sclerosis (MS) by comparing histories of child abuse and neglect between patients with MS and adults from the general population in a cross-sectional case-control study. Previous research has demonstrated a connection between MS and a variety of emotional stressors, but childhood trauma, which is known to have long-lasting negative consequences for physical health decades into adulthood, has not been studied. The self-reported Childhood Trauma Questionnaire for the assessment of emotional, physical, and sexual abuse and emotional and physical neglect was administered to 234 patients with definite MS and 885 adults from the general population. After adjusting for sociodemographic factors and current depression, patients with MS scored significantly higher in all Childhood Trauma Questionnaire subscales apart from physical abuse and neglect than adults from the general population. Adjusted odds ratios for these types of childhood trauma were higher in the MS group than in controls, ranging from 2.0 for emotional neglect (95% confidence interval = 1.3-3.2) to 3.4 for emotional abuse (95% confidence interval = 2.0-5.7). Although childhood trauma was not associated with the degree of current MS-related disability, patients with MS with histories of physical and/or sexual abuse had significantly higher relapse rates than patients without early-life stress. Our findings suggest an association between childhood trauma and MS in this cross-sectional study. Larger prospective longitudinal studies are needed to clarify the relationship between early-life stress and the risk for MS in genetically susceptible individuals.

  13. 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.

  14. Case-control analysis of paternal age and trisomic anomalies.

    PubMed

    De Souza, E; Morris, J K

    2010-11-01

    To determine whether older paternal age increases the risk of fathering a pregnancy with Patau (trisomy 13), Edwards (trisomy 18), Klinefelter (XXY) or XYY syndrome. Case-control: cases with each of these syndromes were matched to four controls with Down syndrome from within the same congenital anomaly register and with maternal age within 6 months. Data from 22 EUROCAT congenital anomaly registers in 12 European countries. Diagnoses with observed or (for terminations) predicted year of birth from 1980 to 2005, comprising live births, fetal deaths with gestational age ≥ 20 weeks and terminations after prenatal diagnosis of the anomaly. Data include 374 cases of Patau syndrome, 929 of Edwards syndrome, 295 of Klinefelter syndrome, 28 of XYY syndrome and 5627 controls with Down syndrome. Odds ratio (OR) associated with a 10-year increase in paternal age for each anomaly was estimated using conditional logistic regression. Results were adjusted to take account of the estimated association of paternal age with Down syndrome (1.11; 95% CI 1.01 to 1.23). The OR for Patau syndrome was 1.10 (95% CI 0.83 to 1.45); for Edwards syndrome, 1.15 (0.96 to 1.38); for Klinefelter syndrome, 1.35 (1.02 to 1.79); and for XYY syndrome, 1.99 (0.75 to 5.26). There was a statistically significant increase in the odds of Klinefelter syndrome with increasing paternal age. The larger positive associations of Klinefelter and XYY syndromes with paternal age compared with Patau and Edwards syndromes are consistent with the greater percentage of these sex chromosome anomalies being of paternal origin.

  15. 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

  16. [Oxidative stress and longevity; a case-control study].

    PubMed

    Belenguer Varea, Ángel; Mohamed Abdelaziz, Kheira; Avellana Zaragoza, Juan Antonio; Borrás Blasco, Consuelo; Sanchis Aguilar, Paula; Viña Ribes, José

    2015-01-01

    Human longevity is a complex issue influenced by genetic and environmental factors. Oxidative stress (OE) could play an important role in this process. Succesful aging could be related with the organism ability facing OE. In the present study we compared malondialdehyde (MDA) and oxidized proteins (OP) plasma levels, in elderly people older than 97 years and 70-80 years old, to better understand the effects of OE on human longevity. Population-based case control study. We considered as cases patients who were born and live on la Ribera county in Valencia (Spain) older than 97 years old and who accepted to participate in the study. Controls were from the same poblational base, chosen randomly, and 70-80 years old. We made a descriptive analysis of sociodemographic, clinic and functional variables; an odds ratio (OR) estimation of being centenarian by OP and MDA quartiles; and a tendency analysis by Mantel-Haenszel test. Twenty eight cases and 31 controls were included. Functional state and robust percentage were worse in cases. MDA (1,44±0,45 vs 1,84±0,59, p=0,005), and OP (64,29±15,73 vs. 76,52±13,44, p=0,002) levels, were significantly lower in cases. The OR of being centenarian in lower/higher quartile were 3,8 for MDA and 5,7 for OP, with a Mantel-Haenszel signification of 0,029 and 0,044 respectively. In our study OE level were lower in centenarians than in younger elderly, and the lower the OE grade, the higher were the likelihood of being centenarian. Copyright © 2014. Published by Elsevier Espana.

  17. 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

  18. Comorbidities in rotator cuff disease: a case-control study.

    PubMed

    Titchener, Andrew G; White, Jonathan J E; Hinchliffe, Sally R; Tambe, Amol A; Hubbard, Richard B; Clark, David I

    2014-09-01

    Rotator cuff disease is a common condition in the general population, but relatively little is known about its associated risk factors. We have undertaken a large case-control study using The Health Improvement Network database to assess and to quantify the relative contributions of some constitutional and environmental risk factors for rotator cuff disease in the community. Our data set included 5000 patients with rotator cuff disease who were individually matched with a single control by age, sex, and general practice (primary care practice). The median age at diagnosis was 55 years (interquartile range, 44-65 years). Multivariate analysis showed that the risk factors associated with rotator cuff disease were Achilles tendinitis (odds ratio [OR] = 1.78), trigger finger (OR = 1.99), lateral epicondylitis (OR = 1.71), and carpal tunnel syndrome (OR = 1.55). Oral corticosteroid therapy (OR = 2.03), oral antidiabetic use (OR = 1.66), insulin use (OR = 1.77), and "overweight" body mass index of 25.1 to 30 (OR = 1.15) were also significantly associated. Current or previous smoking history, body mass index of greater than 30, any alcohol intake, medial epicondylitis, de Quervain syndrome, cubital tunnel syndrome, and rheumatoid arthritis were not found to be associated with rotator cuff disease. We have identified a number of comorbidities and risk factors for rotator cuff disease. These include lateral epicondylitis, carpal tunnel syndrome, trigger finger, Achilles tendinitis, oral corticosteroid use, and diabetes mellitus. The findings should alert the clinician to comorbid pathologic processes and guide future research into the etiology of this condition. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  19. 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.

  20. 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.

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

    PubMed

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

    2010-08-01

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

  2. Mortality in Multicenter Critical Care Trials: An Analysis of Interventions With a Significant Effect.

    PubMed

    Landoni, Giovanni; Comis, Marco; Conte, Massimiliano; Finco, Gabriele; Mucchetti, Marta; Paternoster, Gianluca; Pisano, Antonio; Ruggeri, Laura; Alvaro, Gabriele; Angelone, Manuela; Bergonzi, Pier C; Bocchino, Speranza; Borghi, Giovanni; Bove, Tiziana; Buscaglia, Giuseppe; Cabrini, Luca; Callegher, Lino; Caramelli, Fabio; Colombo, Sergio; Corno, Laura; Del Sarto, Paolo; Feltracco, Paolo; Forti, Alessandro; Ganzaroli, Marco; Greco, Massimiliano; Guarracino, Fabio; Lembo, Rosalba; Lobreglio, Rosetta; Meroni, Roberta; Monaco, Fabrizio; Musu, Mario; Pala, Giovanni; Pasin, Laura; Pieri, Marina; Pisarra, Stefania; Ponticelli, Giuseppe; Roasio, Agostino; Santini, Francesco; Silvetti, Simona; Székely, Andrea; Zambon, Massimo; Zucchetti, Maria Chiara; Zangrillo, Alberto; Bellomo, Rinaldo

    2015-08-01

    We aimed to identify all treatments that affect mortality in adult critically ill patients in multicenter randomized controlled trials. We also evaluated the methodological aspects of these studies, and we surveyed clinicians' opinion and usual practice for the selected interventions. MEDLINE/PubMed, Scopus, and Embase were searched. Further articles were suggested for inclusion from experts and cross-check of references. We selected the articles that fulfilled the following criteria: publication in a peer-reviewed journal; multicenter randomized controlled trial design; dealing with nonsurgical interventions in adult critically ill patients; and statistically significant effect in unadjusted landmark mortality. A consensus conference assessed all interventions and excluded those with lack of reproducibility, lack of generalizability, high probability of type I error, major baseline imbalances between intervention and control groups, major design flaws, contradiction by subsequent larger higher quality trials, modified intention to treat analysis, effect found only after adjustments, and lack of biological plausibility. For all selected studies, we recorded the intervention and its comparator, the setting, the sample size, whether enrollment was completed or interrupted, the presence of blinding, the effect size, and the duration of follow-up. We found 15 interventions that affected mortality in 24 multicenter randomized controlled trials. Median sample size was small (199 patients) as was median centers number (10). Blinded trials enrolled significantly more patients and involved more centers. Multicenter randomized controlled trials showing harm also involved significantly more centers and more patients (p = 0.016 and p = 0.04, respectively). Five hundred fifty-five clinicians from 61 countries showed variable agreement on perceived validity of such interventions. We identified 15 treatments that decreased/increased mortality in critically ill patients in 24

  3. Multicenter Validation of an MMSE-MoCA Conversion Table.

    PubMed

    Bergeron, David; Flynn, Kelsey; Verret, Louis; Poulin, Stéphane; Bouchard, Rémi W; Bocti, Christian; Fülöp, Tamàs; Lacombe, Guy; Gauthier, Serge; Nasreddine, Ziad; Laforce, Robert Jr

    2017-05-01

    Accumulating evidence points to the superiority of the MoCA over the MMSE as a cognitive screening tool. To facilitate the transition from the MMSE to the MoCA in clinical and research settings, authors have developed MMSE-MoCA conversion tables. However, it is unknown whether a conversion table generated from Alzheimer's disease (AD) patients would apply to patients with other dementia subtypes like vascular dementia or frontotemporal dementia. Furthermore, the reliability and accuracy of MMSE-MoCA conversion tables has not been properly evaluated. We retrospectively examined the MMSE-MoCA relationship in a large multicenter sample gathered from 3 Memory Clinics in Quebec, Canada (1492 patients). We produced an MMSE-MoCA conversion table using the equi-percentile method with log-linear smoothing. We then cross-validated our conversion table with the ADNI dataset (1202 patients) and evaluated its accuracy for future predictions. The MMSE-MoCA conversion table is consistent with previously published tables and has an intra-class correlation of 0.633 with the ADNI sample. However, we found that the MMSE-MoCA relationship is significantly modified by diagnosis (P < .01), with dementia subtypes associated with a dysexecutive syndrome showing a trend towards higher MMSE than other dementia syndromes for a given MoCA score. The large width of 95% confidence interval (CI) for a new prediction suggests questionable reliability for clinical use. In this study, we validated a conversion table between MMSE and MoCA using a large multicenter sample. Our results suggest caution in interpreting the tables in heterogeneous clinical populations, as the MMSE-MoCA relationship may be different across dementia subtypes. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

  4. 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

  5. Diet and cataract: a case-control study.

    PubMed

    Theodoropoulou, Sofia; Samoli, Evangelia; Theodossiadis, Panagiotis G; Papathanassiou, Miltiadis; Lagiou, Areti; Lagiou, Pagona; Tzonou, Anastasia

    2014-02-01

    We conducted a case-control study to assess the association between diet and risk of cataract in Athens, Greece. Totals of 314 cases and 314 frequency-matched controls of both sexes, aged 45-85 years and attending the ophthalmology department of a major teaching hospital in Athens, Greece, were included in the study. All participants were interviewed using a semi-quantitative food-frequency questionnaire, covering the average frequency of consumption of about 120 food items. Analyses were conducted through multiple logistic regression. The analysis was carried out taking cataract as a general outcome (all types of cataract combined) and repeated by the specific type of cataract. We found significant inverse associations of cataract with dietary consumption of fish (OR = 0.69, p < 0.001), vegetables (OR = 0.47, p < 0.001), fruits (OR = 0.53, p < 0.001), and potatoes (OR = 0.76, p = 0.004), while consumption of meat was positively associated with cataract (OR = 1.46, p = 0.001). High intake of total fat (OR = 2.00, p < 0.001) and cholesterol (OR = 1.65, p < 0.001) increased the risk of cataract. There was a protective association between cataract risk and intake of carbohydrates (OR = 0.39, p < 0.001), carotene (OR = 0.56, p < 0.001), vitamins C and E (OR = 0.50, p < 0.001 and OR = 0.50, p < 0.001 respectively). We identified an association between the risk of cataract and several food groups and nutrients. Diets rich in fruits, vegetables, fish, pulses and starchy foods may protect against cataract. In addition, high intake of vitamins C and E and carotene with reduction of intake in total fat and cholesterol may be beneficial. Dietary advice along these lines may provide adequate public health guidelines for the delay of age-related cataract.

  6. Multicenter observational prehospital resuscitation on helicopter study.

    PubMed

    Holcomb, John B; Swartz, Michael D; DeSantis, Stacia M; Greene, Thomas J; Fox, Erin E; Stein, Deborah M; Bulger, Eileen M; Kerby, Jeffrey D; Goodman, Michael; Schreiber, Martin A; Zielinski, Martin D; O'Keeffe, Terence; Inaba, Kenji; Tomasek, Jeffrey S; Podbielski, Jeanette M; Appana, Savitri N; Yi, Misung; Wade, Charles E

    2017-07-01

    at any time point, although only 10% of the high-risk sample were able to be matched. Because of the unexpected imbalance in systolic blood pressure, Glasgow Coma Scale, and Injury Severity Score between systems with and without blood products on helicopters, matching was limited, and the results of this study are inconclusive. With few units transfused to each patient and small outcome differences between groups, it is likely large, multicenter, randomized studies will be required to detect survival differences in this important population. Level II.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2000-04-01

    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. 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. 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. 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.

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

    PubMed Central

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

    2009-01-01

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

  11. Case-control admixture mapping in Latino populations enriches for known asthma-associated genes

    PubMed Central

    Torgerson, Dara G.; Gignoux, Christopher R.; Galanter, Joshua M.; Drake, Katherine A.; Roth, Lindsey A.; Eng, Celeste; Huntsman, Scott; Torres, Raul; Avila, Pedro C.; Chapela, Rocio; Ford, Jean G.; Rodríguez-Santana, José R.; Rodríguez-Cintrón, William; Hernandez, Ryan D.; Burchard, Esteban G.

    2012-01-01

    Background Polymorphisms in more than 100 genes have been associated with asthma susceptibility, yet much of the heritability remains to be explained. Asthma disproportionately affects different racial and ethnic groups in the United States, suggesting that admixture mapping is a useful strategy to identify novel asthma-associated loci. Objective We sought to identify novel asthma-associated loci in Latino populations using case-control admixture mapping. Methods We performed genome-wide admixture mapping by comparing levels of local Native American, European, and African ancestry between children with asthma and nonasthmatic control subjects in Puerto Rican and Mexican populations. Within candidate peaks, we performed allelic tests of association, controlling for differences in local ancestry. Results Between the 2 populations, we identified a total of 62 admixture mapping peaks at a P value of less than 10−3 that were significantly enriched for previously identified asthma-associated genes (P = .0051). One of the peaks was statistically significant based on 100 permutations in the Mexican sample (6q15); however, it was not significant in Puerto Rican subjects. Another peak was identified at nominal significance in both populations (8q12); however, the association was observed with different ancestries. Conclusion Case-control admixture mapping is a promising strategy for identifying novel asthma-associated loci in Latino populations and implicates genetic variation at 6q15 and 8q12 regions with asthma susceptibility. This approach might be useful for identifying regions that contribute to both shared and population-specific differences in asthma susceptibility. PMID:22502797

  12. Statin use and risk of endometrial cancer: a nationwide registry-based case-control study.

    PubMed

    Sperling, Cecilie D; Verdoodt, Freija; Friis, Søren; Dehlendorff, Christian; Kjaer, Susanne K

    2017-02-01

    Laboratory and epidemiological evidence have suggested that statin use may protect against the development of certain cancers, including endometrial cancer. In a nationwide registry-based case-control study, we examined the association between statin use and risk of endometrial cancer. Cases were female residents of Denmark with a primary diagnosis of endometrial cancer during 2000-2009. For each case, we selected 15 female population controls matched on date of birth (±one month) using risk-set sampling. Ever use of statin was defined as two or more prescriptions on separate dates. Conditional logistic regressions were used to estimate age-matched (by design) and multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CI) for endometrial cancer associated with statin use. The multivariable-adjusted models included parity, hormone replacement therapy (HRT), obesity, diabetes, chronic obstructive pulmonary disease and education. We evaluated whether the association between statin use and endometrial cancer varied with duration and intensity of statin use, type of endometrial cancer or patient characteristics. The study population comprised 5382 endometrial cancer cases and 72 127 population controls. We observed no association between ever use of statins and endometrial cancer risk (OR 1.03, 95% CI 0.94-1.14). In addition, endometrial cancer risk did not vary substantially with duration or intensity of statin use. Stratification by type of endometrial cancer also yielded neutral ORs. In our nationwide case-control study, we found no association between statin use and risk of endometrial cancer. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

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

    PubMed

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

    2017-02-05

    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. 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. 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). 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 between smoking and DELC was found.

  14. Factors Associated With Unplanned Extubation in Children: A Case-Control Study.

    PubMed

    da Silva, Paulo Sérgio Lucas; Fonseca, Marcelo Cunio Machado

    2017-01-01

    Although several studies assess unplanned extubation (UE) in children, few have addressed determinants of UE and factors associated with reintubation in a case-controlled manner. We aimed to identify the risk factors and outcomes associated with UE in a pediatric intensive care unit. Cases of UE were randomly matched with control patients at a ratio of 1:4 for age, severity of illness, and admission diagnosis. For cases and controls, we also collected data associated with UE events, reintubation, and outcomes. We analyzed 94 UE patients (0.75 UE per 100 intubation days) and found no differences in demographics between the 2 groups. Logistic regression revealed that patient agitation (odds ratio [OR]: 2.44; 95% confidence interval [CI]: 1.28-4.65), continuous sedation infusion (OR: 3.27; 95% CI: 1.70-6.29), night shifts (OR: 9.16; 95% CI: 4.25-19.72), in-charge nurse experience <2 years (OR: 2.38; 95% CI: 1.13-4.99), and oxygenation index (OI) >5 (OR: 76.9; 95% CI: 16.79-352.47) were associated with UE. Risk factors for reintubation after UE included prior level of sedation (COMFORT score < 27; OR: 7.93; 95% CI: 2.30-27.29), copious secretion (OR: 11.88; 95% CI: 2.20-64.05), and OI > 5 (OR: 9.32; 95% CI: 2.45-35.48). This case-control study showed that both patient- and nurse-associated risk factors were related to UE. Risk factors associated with reintubation included lower levels of consciousness, copious secretions, and higher OI. Further evidence-based studies, including a larger sample size, are warranted to identify predisposing factors in UEs.

  15. Limited hip rotation and non-contact anterior cruciate ligament injury: a case-control study.

    PubMed

    Tainaka, Koji; Takizawa, Tsuyoshi; Kobayashi, Hiroyuki; Umimura, Masakazu

    2014-01-01

    Insufficient hip flexibility, a limiting factor for lower extremity rotation, can cause great rotational stress and consequent injury to the knees and ankles. A limited range of motion (ROM) of the hip might be associated with increased risk of non-contact anterior cruciate ligament (ACL) injury. We investigated the association between the risk of non-contact ACL injured student athletes and limitations of hip ROM. A case-control study was conducted at an orthopaedic clinic in Japan. Cases included all patients with non-contact ACL injury and without known marked alignment abnormalities who visited the orthopaedic clinic during 2000-2008. Controls included all patients with non-ACL sports-related injuries who visited the same clinic in 2000. The adjusted odds ratio of ROM of the hip was evaluated for non-contact ACL injury risk. These cases were 44 ACL cases and 123 controls aged 13-17 years. The odds ratios (ORs) of internal and external rotations of hip ROMs were adjusted for age, sex, BMI, type of sports and hip ROM (flexion, extension, adduction, abduction). The adjusted ORs for a 10° increase of the sum of the right and left internal hip rotations were 0.18 (95% confidence interval [CI], 0.10-0.34, p<0.0001), and 0.23 (95% CI, 0.14-0.39, p<0.0001) for external rotations, and the observed ORs were small. Data obtained from this small sample indicate that limited hip rotation ROMs in young athletes have the possibility of association with increased risk of non-contact ACL injury. III - case-control study. © 2013.

  16. Case-control admixture mapping in Latino populations enriches for known asthma-associated genes.

    PubMed

    Torgerson, Dara G; Gignoux, Christopher R; Galanter, Joshua M; Drake, Katherine A; Roth, Lindsey A; Eng, Celeste; Huntsman, Scott; Torres, Raul; Avila, Pedro C; Chapela, Rocio; Ford, Jean G; Rodríguez-Santana, José R; Rodríguez-Cintrón, William; Hernandez, Ryan D; Burchard, Esteban G

    2012-07-01

    Polymorphisms in more than 100 genes have been associated with asthma susceptibility, yet much of the heritability remains to be explained. Asthma disproportionately affects different racial and ethnic groups in the United States, suggesting that admixture mapping is a useful strategy to identify novel asthma-associated loci. We sought to identify novel asthma-associated loci in Latino populations using case-control admixture mapping. We performed genome-wide admixture mapping by comparing levels of local Native American, European, and African ancestry between children with asthma and nonasthmatic control subjects in Puerto Rican and Mexican populations. Within candidate peaks, we performed allelic tests of association, controlling for differences in local ancestry. Between the 2 populations, we identified a total of 62 admixture mapping peaks at a P value of less than 10(-3) that were significantly enriched for previously identified asthma-associated genes (P= .0051). One of the peaks was statistically significant based on 100 permutations in the Mexican sample (6q15); however, it was not significant in Puerto Rican subjects. Another peak was identified at nominal significance in both populations (8q12); however, the association was observed with different ancestries. Case-control admixture mapping is a promising strategy for identifying novel asthma-associated loci in Latino populations and implicates genetic variation at 6q15 and 8q12 regions with asthma susceptibility. This approach might be useful for identifying regions that contribute to both shared and population-specific differences in asthma susceptibility. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  17. Association between protozoa in sputum and asthma: a case-control study.

    PubMed

    van Woerden, Hugo C; Ratier-Cruz, Adriana; Aleshinloye, Olabode B; Martinez-Giron, Rafael; Gregory, Clive; Matthews, Ian P

    2011-06-01

    Atypical infectious agents have been proposed as potential contributors to asthma. A novel set of morphological and staining criteria permit the identification of flagellated protozoa in sputum. This case-control study was designed to use this novel method and to assess: (1) are protozoa more common in asthmatics than in non-asthmatics; (2) is the presence of protozoa associated with the use of steroid inhalers; and (3) is the presence of protozoa associated with living in damp housing? Induced sputum samples were collected from asthma patients and local non-atopic, non-smoking controls. Questionnaires assessed asthma severity and housing conditions. Sputum was examined for flagellated protozoa using a previously described staining technique. 96 participants were recruited for this study; 54 asthma patients and 42 controls, age range 21-62 years, 70% female participants. Limiting results to those who were clearly positive or negative for flagellated protozoa, 66.7% (20/30) of asthmatics and 30.8% (4/13) of controls had protozoa (p = 0.046). Among the asthma patients, prevalence of protozoa was not significantly different between those who had (10/18), and those who had not (10/12), used steroid inhaler in the preceding two weeks (p = 0.11). Similarly, the prevalence of protozoa was not significantly different between those who did (6/11) and those who did not (18/32), live in damp homes (p = 0.92). This case-control study demonstrates an association between flagellated protozoa in sputum and asthma. It is now necessary to confirm and characterise the protozoa using genetic techniques based on 18S ribosomal RNA. Once tis is established it would be worthwhile to determine if asthma symptoms improve when treated by anti-protozoal agents. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. 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.

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

    PubMed

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

    2014-02-01

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

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

    PubMed

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

    2016-12-22

    To test the association between diabetes and tuberculosis. 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. 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). 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. Testar a associação entre diabetes e tuberculose. Trata-se de estudo caso-controle, pareado por idade e sexo. Foram incluídos 323 casos novos de tuberculose com resultados positivos à baciloscopia. Os controles foram 323 sintomáticos respiratórios com baciloscopia negativa, oriundos dos mesmos serviços de saúde dos casos: ambulatórios de três hospitais de referência e seis unidades básicas de saúde responsáveis pelas notificações dos casos novos de

  1. 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

  2. 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.

  3. Risk factors for in-hospital venous thromboembolism in children: a case-control study employing diagnostic validation.

    PubMed

    Branchford, Brian R; Mourani, Peter; Bajaj, Lalit; Manco-Johnson, Marilyn; Wang, Michael; Goldenberg, Neil A

    2012-04-01

    Studies evaluating risk factors for in-hospital venous thromboembolism in children are limited by quality assurance of case definition and/or lack of controlled comparison. The objective of this study is to determine risk factors for the development of in-hospital venous thromboembolism in children. In a case-control study at The Children's Hospital, Colorado, from 1(st) January 2003 to 31(st) December 2009 we employed diagnostic validation methods to determine pediatric in-hospital venous thromboembolism risk factors. Clinical data on putative risk factors were retrospectively collected from medical records of children with International Classification of Diseases, 9th edition codes of venous thromboembolism at discharge, in whom radiological reports confirmed venous thromboembolism and no signs/symptoms of venous thromboembolism were noted on admission. We verified 78 cases of in-hospital venous thromboembolism, yielding an average incidence of 5 per 10,000 hospitalized children per year. Logistical regression analyses revealed that mechanical ventilation, systemic infection, and hospitalization duration of five days or over were statistically significant, independent risk factors for in-hospital venous thromboembolism (OR=3.29, 95%CI=1.53-7.06, P=0.002; OR=3.05, 95%CI=1.57-5.94, P=0.001; and OR=1.03, 95%CI=1.01-1.04, P=0.001, respectively). Using these factors in a risk model, post-test probability of venous thromboembolism was 3.6%. These data indicate that risk of in-hospital venous thromboembolism in children with this risk factor combination may exceed that of hospitalized adults in whom prophylactic anticoagulation is indicated. Substantiation of these findings via multicenter studies could provide the basis for future risk-stratified randomized control trials of pediatric venous thromboembolism prevention.

  4. 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

  5. [Pneumonia in the elderly population over 70 years with limited functional condition: case-control study of institutionalized patients].

    PubMed

    Serra Sanchis, B; Martínez Moragón, E; Aguar, M; Fernández Fabrellas, E; Sanz, F; Blanquer, J

    2007-12-01

    Community acquired pneumonia (CAP) of the elderly is an increasingly important growing health problem due to its prevalence and mortality. Among the factors that are usually related with poor evolution are advanced age, poor functional status and coming from a socio-health care institution such as residential homes for the elderly. In this study, we have chosen a population over 70 years of age with limited functional capacity (Barthel Index < 50) in order to know if coming from a residential home for the elderly is an isolated factor that is associated to worse prognosis of CAP. We selected 87 patients over 70 years from a prospective and multicenter study of the hospitalized CAPs during one year. We analyzed the evolution and course of the CAP based on place or origin and then conducted a case-control study of the elderly over 70 years with the Barthel under 50, including 21 elderly from residences and 21 from the own home. In elderly patients over 70 years with CAP, those coming from the residence have a confusional picture more often and come to emergency with lower values of systolic and diastolic blood pressure, lower arterial oxygen saturation, greater involvement on the x-ray, Fine Index is worse and die more often. When we limit the population to those over 70 years with Barthel under 50, we do not find differences in institutionalized patients versus the others. In the elderly over 70 years with CAP, patients from assisted living residences have greater mortality. However, when functional capacity is bad (Barthel < 50), place or origin (community or elderly residence) loses importance and becomes a variable that has no more influence than others in the clinical evolution and course of the CAP.

  6. Outcome of acute upper gastrointestinal bleeding in patients with coronary artery disease: A matched case-control study.

    PubMed

    Thanapirom, Kessarin; Ridtitid, Wiriyaporn; Rerknimitr, Rungsun; Thungsuk, Rattikorn; Noophun, Phadet; Wongjitrat, Chatchawan; Luangjaru, Somchai; Vedkijkul, Padet; Lertkupinit, Comson; Poonsab, Swangphong; Ratanachu-Ek, Thawee; Hansomburana, Piyathida; Pornthisarn, Bubpha; Thongbai, Thirada; Mahachai, Varocha; Treeprasertsuk, Sombat

    2016-01-01

    The risk of upper gastrointestinal bleeding (UGIB) increases in patients with coronary artery disease (CAD) due to the frequent use of antiplatelets. There is some data reporting on treatment outcomes in CAD patients presenting with UGIB. We aim to determine the clinical characteristics and outcomes of UGIB in patients with CAD, compared with non-CAD patients. We conducted a prospective multi-center cohort study (THAI UGIB-2010) that enrolled 981 consecutive hospitalized patients with acute UGIB. A matched case-control analysis using this database, which was collected from 11 tertiary referral hospitals in Thailand between January 2010 and September 2011, was performed. Of 981 hospitalized patients with UGIB, there were 61 CAD patients and 244 gender-matched non-CAD patients (ratio 1:4). UGIB patients with CAD were significantly older, and had more frequently used antiplatelets and warfarin than in non-CAD patients. Compared with non-CAD, the CAD patients had significantly higher Glasgow-Blatchford score, full and pre-endoscopic Rockall score and full. Peptic ulcer in CAD patients was identified more often than in non-CAD patients. UGIB patients with CAD and non-CAD had similar outcomes with regard to mortality rate, re-bleeding, surgery, embolization, and packed erythrocyte transfusion. However, CAD patients had longer duration of hospital stays than non-CAD patients. Two CAD patients died from cardiac arrest after endoscopy, whereas three non-CAD patients died from pneumonia and acute renal failure during their hospitalization. In Thailand, patients presenting with UGIB, concomitant CAD did not affect clinical outcome of treatment, compared with non-CAD patients, except for longer hospital stay.

  7. 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

  8. 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.

  9. 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.

  10. Risk factors for maternal mortality in Delhi slums: a community-based case-control study.

    PubMed

    Aggarwal, Abha; Pandey, Arvind; Bhattacharya, B N

    2007-09-01

    In order to develop, implement and evaluate policy for reducing maternal mortality, it is essential to study the risk factors associated with maternal deaths. The study aims to determine the epidemiological risk factors and its related causes associated with maternal deaths in Delhi slums. A community-based case-control study was designed, wherein snowball-sampling method was used to identify the maternal deaths (cases) in the community and circular systematic random sampling procedure was used to select the controls from the same area where a maternal death was found. Data on 70 cases and 384 controls that had live births as the outcome of the pregnancy were analyzed. Logistic regression was applied to identify the risk factors. In the study population, most of the deliveries were conducted at home by untrained 'dais.' Cases were mostly illiterate, young, having high parity and no antenatal care taken during pregnancy (P CONCLUSIONS: The study findings suggest that women should be educated about the importance of antenatal registration and regular checkups. Untrained 'dais' should be trained to recognize the obstetric complications at an early stage and refer high-risk cases for adequate management. These preventive measures could help in reducing maternal mortality at the community level.

  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. Overcoming the Winner’s Curse: Estimating Penetrance Parameters from Case-Control Data

    PubMed Central

    Zöllner, Sebastian; Pritchard, Jonathan K.

    2007-01-01

    Genomewide association studies are now a widely used approach in the search for loci that affect complex traits. After detection of significant association, estimates of penetrance and allele-frequency parameters for the associated variant indicate the importance of that variant and facilitate the planning of replication studies. However, when these estimates are based on the original data used to detect the variant, the results are affected by an ascertainment bias known as the “winner’s curse.” The actual genetic effect is typically smaller than its estimate. This overestimation of the genetic effect may cause replication studies to fail because the necessary sample size is underestimated. Here, we present an approach that corrects for the ascertainment bias and generates an estimate of the frequency of a variant and its penetrance parameters. The method produces a point estimate and confidence region for the parameter estimates. We study the performance of this method using simulated data sets and show that it is possible to greatly reduce the bias in the parameter estimates, even when the original association study had low power. The uncertainty of the estimate decreases with increasing sample size, independent of the power of the original test for association. Finally, we show that application of the method to case-control data can improve the design of replication studies considerably. PMID:17357068

  13. 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.

  14. CASE-CONTROL SURVIVAL ANALYSIS WITH A GENERAL SEMIPARAMETRIC SHARED FRAILTY MODEL - A PSEUDO FULL LIKELIHOOD APPROACH.

    PubMed

    Gorfine, Malka; Zucker, David M; Hsu, Li

    2009-01-01

    In this work we deal with correlated failure time (age at onset) data arising from population-based case-control studies, where case and control probands are selected by population-based sampling and an array of risk factor measures is collected for both cases and controls and their relatives. Parameters of interest are effects of risk factors on the failure time hazard function and within-family dependencies among failure times after adjusting for the risk factors. Due to the retrospective sampling scheme, large sample theory for existing methods has not been established. We develop a novel technique for estimating the parameters of interest under a general semiparametric shared frailty model. We also present a simple, easily computed, and non-iterative nonparametric estimator for the cumulative baseline hazard function. We provide rigorous large sample theory for the proposed method. We also present simulation results and a real data example for illustrating the utility of the proposed method.

  15. Risk factors for syphilis in women: case-control study.

    PubMed

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

    2017-08-17

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

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

    PubMed

    Cantonwine, David; Meeker, John D; Hu, Howard; Sánchez, Brisa N; Lamadrid-Figueroa, Héctor; Mercado-García, Adriana; Fortenberry, Gamola Z; Calafat, Antonia M; Téllez-Rojo, Martha Maria

    2010-10-18

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

  17. The business case for bariatric surgery revisited: a non-randomized case-control study.

    PubMed

    Finkelstein, Eric A; Allaire, Benjamin T; Globe, Denise; Dixon, John B

    2013-01-01

    Prior studies reporting that bariatric surgery (including laparoscopic adjustable gastric band (LAGB) and [laparoscopic Roux-en-Y] Gastric Bypass (LRYGB)) is cost-saving relied on a comparison sample of those with a morbid obesity (MO) diagnosis code, a high cost group who may not be reflective of those who opt for the procedures. We re-estimate net costs and time to breakeven using an alternative sample that does not rely on this code. Non-randomized case-control study using medical claims data from a commercial database in the USA. LAGB and LRYGB claimants were propensity score matched to two control samples: one restricted to those with a MO diagnosis code and one without this restriction. When using the MO sample, costs for LAGB and LRYGB are recovered in 1.5 (Confidence Interval [CI]: 1.45 to 1.55) and 2.25 years (CI: 2.07 to 2.43), and 5 year savings are $78,980 (CI: 62,320 to 100,550) for LAGB and $61,420 (CI: 44,710 to 82,870) for LRYGB. Without the MO requirement, time to breakeven for LAGB increases to 5.25 (CI: 4.25 to 10+) years with a 5 year net cost of $690 (CI: 6,800 to 8.400). For LRYGB, time to breakeven exceeds 10 years and 5 year net costs are $18,940 (CI: 10,390 to 26,740). The net costs and time to breakeven resulting from bariatric surgery are likely less favorable than has been reported in prior studies, and especially for LRYGB, with a time to breakeven of more than twice the 5.25 year estimate for LAGB.

  18. Ocular Tonometry and Sporadic Creutzfeldt - Jakob Disease (sCJD): A Confirmatory Case-Control Study.

    PubMed

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

    2014-04-30

    To evaluate the hypothesis that sporadic Creutzfeldt-Jakob disease (sCJD) may be transmitted through ocular tonometry. The infectious agent of sCJD may be present in the cornea prior to clinical symptoms. Cornea infectiousness has been documented by cornea transplants in guinea pigs and humans. sCJD is resistant to complete inactivity by conventional sterilization techniques. Thus contact tonometry equipment is not disinfected sufficiently to kill sCJD. We previously hypothesized that contact tonometry is a sCJD risk factor. Population-based case-control study. Department of Neurology, School of Medicine, Loma Linda University, Loma Linda, CA, USA; 4 years. An 11-state case-control study of pathologically confirmed definite sCJD cases, individually matched controls, and a sample of control surrogates was conducted. Ocular tonometry histories were obtained from case-surrogates, controls, and a sample of control-surrogates. The odds ratio (OR) for ever vs never having had an ocular tonometry test was statistically significant for matched and unmatched analyses for 15 through 3 years prior to disease onset, using both control self-responses and control surrogates: ORs were ∞ and 19.4 with 1-sided P-values <0.0001 and 0.003 and ORs=∞ and 11.1 with 1-sided P-values <0.003 and 0.02, respectively. ORs increased as the number of tonometry tests increased during this age period: trend test, 2-sided P-value < 0.0001. For ≥5 vs <5 tonometry tests, the OR was 5.8 (unmatched) and 3.7 (matched), 2-sided P-value<0.00005. Respondents generally could not specify the type of tonometry. There was no indication of increased tonometry testing among cases within 2 years of disease onset. The a priori hypothesis was supported. Contact tonometry, preferred by ophthalmologists, may be capable of transmitting sCJD. Consideration should be given to using disposable instrument covers after each use. The use the disposable covers or non-contact tonometry is preferable in the absence of

  19. 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

  20. Epidemiological study of prostate cancer (EPICAP): a population-based case-control study in France.

    PubMed

    Menegaux, Florence; Anger, Antoinette; Randrianasolo, Hasina; Mulot, Claire; Laurent-Puig, Pierre; Iborra, François; Bringer, Jean-Pierre; Leizour, Benoit; Thuret, Rodolphe; Lamy, Pierre-Jean; Rébillard, Xavier; Trétarre, Brigitte

    2014-02-19

    Prostate cancer is the most common cancer in male in most Western countries, including France. Despite a significant morbidity and mortality to a lesser extent, the etiology of prostate cancer remains largely unknown. Indeed, the only well-established risk factors to date are age, ethnicity and a family history of prostate cancer. We present, here, the rationale and design of the EPIdemiological study of Prostate CAncer (EPICAP), a population-based case-control study specifically designed to investigate the role of environmental and genetic factors in prostate cancer. The EPICAP study will particularly focused on the role of circadian disruption, chronic inflammation, hormonal and metabolic factors in the occurrence of prostate cancer. EPICAP is a population-based case-control study conducted in the département of Hérault in France. Eligible cases are all cases of prostate cancers newly diagnosed in 2012-2013 in men less than 75 years old and residing in the département of Hérault at the time of diagnosis. Controls are men of the same age as the cases and living in the département of Hérault, recruited in the general population.The sample will include a total of 1000 incident cases of prostate cancer and 1000 population-based controls over a 3-year period (2012-2014).The cases and controls are face-to-face interviewed using a standardized computed assisted questionnaire. The questions focus primarily on usual socio-demographic characteristics, personal and family medical history, lifestyle, leisure activities, residential and occupational history. Anthropometric measures and biological samples are also collected for cases and controls. The EPICAP study aims to answer key questions in prostate cancer etiology: (1) role of circadian disruption through the study of working hours, chronotype and duration/quality of sleep, (2) role of chronic inflammation and anti-inflammatory drugs, (3) role of hormonal and metabolic factors through a detailed questionnaire, (4

  1. 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…

  2. Multicenter neonatal databases: Trends in research uses.

    PubMed

    Creel, Liza M; Gregory, Sean; McNeal, Catherine J; Beeram, Madhava R; Krauss, David R

    2017-01-13

    In the US, approximately 12.7% of all live births are preterm, 8.2% of live births were low birth weight (LBW), and 1.5% are very low birth weight (VLBW). Although technological advances have improved mortality rates among preterm and LBW infants, improving overall rates of prematurity and LBW remains a national priority. Monitoring short- and long-term outcomes is critical for advancing medical treatment and minimizing morbidities associated with prematurity or LBW; however, studying these infants can be challenging. Several large, multi-center neonatal databases have been developed to improve research and quality improvement of treatments for and outcomes of premature and LBW infants. The purpose of this systematic review was to describe three multi-center neonatal databases. We conducted a literature search using PubMed and Google Scholar over the period 1990 to August 2014. Studies were included in our review if one of the databases was used as a primary source of data or comparison. Included studies were categorized by year of publication; study design employed, and research focus. A total of 343 studies published between 1991 and 2014 were included. Studies of premature and LBW infants using these databases have increased over time, and provide evidence for both neonatology and community-based pediatric practice. Research into treatment and outcomes of premature and LBW infants is expanding, partially due to the availability of large, multicenter databases. The consistency of clinical conditions and neonatal outcomes studied since 1990 demonstrates that there are dedicated research agendas and resources that allow for long-term, and potentially replicable, studies within this population.

  3. Distal scar-to-midline distance in pilonidal Limberg flap surgery is a recurrence-promoting factor: A multicenter, case-control study.

    PubMed

    Kaplan, Mehmet; Ozcan, Onder; Bilgic, Ethem; Kaplan, Elif Tugce; Kaplan, Tugba; Kaplan, Fatma Cigdem

    2017-03-09

    The Limberg flap (LF) procedure is widely performed for the treatment of sacrococcygeal pilonidal sinus (SPS); however, recurrences continues to be observed. The aim of this study was to assess the relationship between LF designs and the risk of SPS recurrence. Sixty-one cases with recurrent disease (study group) and 194 controls, with a minimum of 5 recurrence-free years following surgery (control group), were included in the study. LF reconstructions performed in each group were classified as off-midline closure (OMC) and non-OMC types. Subsequently, the 2 groups were analyzed. After adjustment for all variables, non-OMC types showed the most prominent correlation with recurrence, followed by interrupted suturing type, family history of SPS, smoking, prolonged healing time, and younger age. The best cut-off value for the critical distance from the midline was found to be 11 mm (with 72% sensitivity and 95% specificity for recurrence). We recommend OMC modifications, with the flap tailored to create a safe margin of at least 2 cm between the flap borders and the midline. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    PubMed

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

    2015-11-01

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

  5. Hair dye use, regular exercise, and the risk and prognosis of prostate cancer: multicenter case-control and case-only studies.

    PubMed

    Tai, Shu-Yu; Hsieh, Hui-Min; Huang, Shu-Pin; Wu, Ming-Tsang

    2016-03-21

    This study investigated the effects that hair dye use and regular exercise exert on the risk and prognosis of prostate cancer. We studied 296 cases of histologically confirmed prostate cancer and 296 age- (in 2-y bands), ethnicity-, and hospital-matched controls in Taiwan between August 2000 and December 2008. To determine the rate of prostate cancer survival, another 608 incident prostate cancer cases occurring between August 2000 and December 2007 were investigated. Information on hair dye use and regular exercise was obtained using a standardized questionnaire. The use of hair dyes was associated with a significant 2.15-fold odds of developing prostate cancer (adjusted odds ratio = 2.15, 95% confidence interval [CI] = 1.32-3.57), but was not associated with prostate cancer survival, compared with no use. The significant risks were more prominent in users aged < 60 years who had used hair dyes for > 10 years, > 6 times per year, and started using hair dyes before 1980. By contrast, regular exercise significantly reduced the number of prostate-cancer-specific death (adjusted hazard ratio = 0.37, 95% CI = 0.16-0.83); the protective effect of exercise was more prominent among cancer patients who exercised daily (≥ 7 times/week). However, exercise could not prevent the development of prostate cancer. Hair dye use increased the risk of prostate cancer, whereas regular exercise reduced the number of prostate-cancer-specific deaths.

  6. Effect of perioperative oral care on prevention of postoperative pneumonia associated with esophageal cancer surgery: A multicenter case-control study with propensity score matching analysis.

    PubMed

    Soutome, Sakiko; Yanamoto, Souichi; Funahara, Madoka; Hasegawa, Takumi; Komori, Takahide; Yamada, Shin-Ichi; Kurita, Hiroshi; Yamauchi, Chika; Shibuya, Yasuyuki; Kojima, Yuka; Nakahara, Hirokazu; Oho, Takahiko; Umeda, Masahiro

    2017-08-01

    The aim of this study was to investigate the effectiveness of oral care in prevention of postoperative pneumonia associated with esophageal cancer surgery.Postoperative pneumonia is a severe adverse event associated with esophageal cancer surgery. It is thought to be caused by aspiration of oropharyngeal fluid containing pathogens. However, the relationship between oral health status and postoperative pneumonia has not been well investigated.This study included 539 patients with esophageal cancer undergoing surgery at 1 of 7 university hospitals. While 306 patients received perioperative oral care, 233 did not. Various clinical factors as well as occurrence of postoperative pneumonia were retrospectively evaluated. Propensity-score matching was performed to minimize selection biases associated with comparison of retrospective data between the oral care and control groups. Factors related to postoperative pneumonia were analyzed by logistic regression analysis.Of the original 539 patients, 103 (19.1%) experienced postoperative pneumonia. The results of multivariate analysis of the 420 propensity score-matched patients revealed longer operation time, postoperative dysphagia, and lack of oral care intervention to be significantly correlated with postoperative pneumonia.The present findings demonstrate that perioperative oral care can reduce the risk of postoperative pneumonia in patients undergoing esophageal cancer surgery.

  7. 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.

  8. 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.

  9. Clinicopathological features of patients with malignant mesothelioma in a multicenter, case-control study: no role for ABO-Rh blood groups.

    PubMed

    Utkan, Güngör; Ürün, Yüksel; Cangir, Ayten Kayi; Kılıç, Dalokay; Özdemir, Nuriye Yildirim; Oztuna, Derya Gokmen; Bulut, Erhan; Arslan, Ülkü Yalçintaş; Koçer, Murat; Kavukçu, Şevket; İçli, Fikri

    2013-01-01

    Malignant mesothelioma (MM) is an aggressive tumor of mesothelial surfaces. Previous studies have observed an association between ABO blood groups and risk of certain malignancies, including pancreatic and gastric cancer; however, no information on any association with MM risk is available. The aim of this study was to investigate possible associations amoong MM clinicopathological features and ABO blood groups and Rh factor. In 252 patients with MM, the ABO blood group and Rh factor were examined and compared with the control group of 3,022,883 healthy volunteer blood donors of Turkish Red Crescent between 2004 and 2011. The relationship of blood groups with various clinicopathological features were also evaluated in the patient group. The median age was 55 (range: 27-86) and 61.5% of patients were male. While 82.8% of patients had a history of exposure to asbestos, 60.7% of patients had a smoking history. Epithelioid (65.1%) was the most common histology and 18.7% of patients had mixed histology. Overall, the ABO blood group distribution of the 252 patients with MM was comparable with the general population. The median overall survival (OS) was 14 months (95% confidence interval, 11.3-16.6 months). The median OS for A, B, AB, and O were 11, 15, 16, and 15 months respectively (p=0.396). First line chemotherapy was administered to 118 patients. The median OS of patients on pemetrexed or gemcitabine was longer than patient who was not administered chemotherapy [17 months (95%CI, 11.7-22.2) vs. 9 months (95%CI, 6.9-11.0); p<0.001]. The results of this study suggest that patients with MM can benefit from treatment with pemetrexed or gemcitabine in combination with cisplatin. We did not observe a statistically significant association between ABO blood group and risk of MM.

  10. Variation in the Lysyl Oxidase (LOX) Gene Is Associated with Keratoconus in Family-Based and Case-Control Studies

    PubMed Central

    Bykhovskaya, Yelena; Li, Xiaohui; Epifantseva, Irina; Haritunians, Talin; Siscovick, David; Aldave, Anthony; Szczotka-Flynn, Loretta; Iyengar, Sudha K.; Taylor, Kent D.; Rotter, Jerome I.; Rabinowitz, Yaron S

    2012-01-01

    Purpose. Keratoconus is a bilateral noninflammatory progressive corneal disorder with complex genetic inheritance and a common cause for cornea transplantation in young adults. A genomewide linkage scan in keratoconus families identified a locus at 5q23.2, overlapping the gene coding for the lysyl oxidase (LOX). LOX encodes an enzyme responsible for collagen cross-linking in a variety of tissues including the cornea. Corneal collagen cross-linking with long-wave ultraviolet light and riboflavin is a promising new treatment for keratoconus. To determine whether LOX is a genetic determinant of the pathogenesis of keratoconus, we analyzed association results of LOX polymorphisms in two independent case-control samples and in keratoconus families. Methods. Association results were analyzed of single-nucleotide polymorphisms (SNPs) in the LOX gene from a Genome-Wide Association Study (GWAS) investigation in two independent panels of patients with keratoconus and controls and in keratoconus families. Results. Evidence of association was found at SNPs rs10519694 and rs2956540 located in intron 4 of LOX in the GWAS discovery case-control panel with P values of 2.3 × 10−3 and 7 × 10−3, respectively. The same two SNPs were found to be associated with keratoconus by family-based association testing with P values of 2.7 × 10−3 and 7.7 × 10−4, respectively. Meta P values of 4.0 × 10−5 and 4.0 × 10−7 were calculated for SNPs rs10519694 and rs2956540 by analyzing case-control and family samples simultaneously. Sequencing of LOX exons in a subset of keratoconus patients identified two polymorphisms, rs1800449 and rs2288393, located in LOX transcripts I and II, associated with keratoconus in case-control and family samples with a meta P value of 0.02. Conclusions. Results provided strong genetic evidence that LOX variants lead to increased susceptibility to developing of keratoconus. PMID:22661479

  11. 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.

  12. Lung cancer correlates in Lebanese adults: a pilot case--control study.

    PubMed

    Aoun, Joseph; Saleh, Nadine; Waked, Mirna; Salamé, Joseph; Salameh, Pascale

    2013-12-01

    Lung cancer is one of the most prevalent types of cancers. However, there are no epidemiological studies concerning lung cancer and its risk factors in Lebanon. This study was carried out to determine the association between lung cancer and its most common risk factors in a sample of the Lebanese population. A hospital-based case-control study was conducted. Patients were recruited in a tertiary health care center. A questionnaire in Arabic was designed to assess the possible risk factors for lung cancer. For females, cigarette smoking (ORa=9.76) and using fuel for heating (ORa=9.12) were found to be the main risk factors for lung cancer; for males, cigarette smoking (ORa=156.98), living near an electricity generator (ORa=13.26), consuming low quantities of fruits and vegetables (ORa=10.54) and a family history of cancer (ORa=8.75) were associated with lung cancer. Waterpipe smoking was significantly correlated with lung cancer in the bivariate analysis. In this pilot study, it was found that in addition to smoking, outdoor and indoor pollution factors were potential risk factors of lung cancer. Additional studies would be necessary to confirm these findings. Copyright © 2013 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

  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. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

    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.

  15. 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.

  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. 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

  18. Assessment of biomarkers for risk prediction with nested case-control studies.

    PubMed

    Zhou, Qian M; Zheng, Yingye; Cai, Tianxi

    2013-10-01

    Accurate risk prediction plays a key role in disease prevention and disease management; emergence of new biomarkers may lead to an important question about how much improvement in prediction accuracy it would achieve by adding the new markers into the existing risk prediction tools. In large prospective cohort studies, the standard full-cohort design, requiring marker measurement on the entire cohort, may be infeasible due to cost and low rate of the clinical condition of interest. To overcome such difficulties, nested case-control (NCC) studies provide cost-effective alternatives but bring about challenges in statistical analyses due to complex data sets generated. To evaluate prognostic accuracy of a risk model, Cai and Zheng proposed a class of nonparametric inverse probability weighting (IPW) estimators for accuracy measures in the time-dependent receiver operating characteristic curve analysis. To accommodate a three-phase NCC design in Nurses' Health Study, we extend the double IPW estimators of Cai and Zheng to develop risk prediction models under time-dependent generalized linear models and evaluate the incremental values of new biomarkers and genetic markers. Our results suggest that aggregating the information from both the genetic markers and biomarkers substantially improves the accuracy for predicting 5-year and 10-year risks of rheumatoid arthritis. Our method provided robust procedures to evaluate the incremental value of new biomarkers allowing for complex sampling designs.

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. [A case-control study of the influence of the smoking behaviour in multiple sclerosis].

    PubMed

    Rodríguez Regal, A; del Campo Amigo, M; Paz-Esquete, J; Martínez Feijoo, A; Cebrián, E; Suárez Gil, P; Mouriño, M A

    2009-04-01

    Several epidemiological studies have demonstrated that there is a genetic factor of susceptibility in Multiple Sclerosis (MS) and that the environmental factors play an important important role in their development. Smoking is among the environment factors studied. In fact, several studies have established a relationship between smoking and multiple sclerosis, although most of them did not find significant results or found that these were contradictory. To evaluate the influence of the smoking habit on the risk of suffering MS. This was a case-control matched study with 138 patients diagnosed of MS according to the McDonald criteria who were paired with the same number of controls of the same gender, residents in the same city and having the same age +/-2 years. Demographic data, smoking status (never, always smokers, ex-smokers), Kurtzke disability status scale (EDSS) and type of MS were collected. Out of a total of 138 MS patients (93 women, 43 men), 110 had relapsing-remitting MS, 20 secondary progressive MS and 7 primary progressive MS. Most of the patients were smokers and ex-smokers (63%). In the control group, only the 41,3% were smokers/ex-smokers. Moreover, the age of onset for smoking was earlier in the case group. Being a smoker/ex-smoker implies a 27% greater risk of developing MS compared to those who have never smoked. This risk is statistically significant for women but not for men due to the low number of them in the sample.

  4. Risk factors of early childhood caries among children in Beijing: a case-control study.

    PubMed

    Fan, Cancan; Wang, Wenhui; Xu, Tao; Zheng, Shuguo

    2016-09-17

    The prevalence of early childhood caries (ECC) among children in Beijing, China, has been increasing continuously though slowly. However, there is limited information about ECC in Beijing. The aim of this study was to identify risk factors of dental caries among preschool children in Beijing. For this case-control study, using a convenience sampling method, 787 children aged 3 and 4 years old were recruited; 386 children with caries constituted the early childhood caries (ECC) group and 401children without caries formed the caries-free (CF) group. Dental caries was diagnosed at the tooth surface level by two calibrated examiners according to the WHO 1997 criteria. A structured questionnaire was filled in by the children's main guardians. Mutans streptococci in non stimulated saliva and plaque were measured with the Dentocult SM Strip. Negative binomial regression was used for multivariate analysis. Analysis of the data showed that level of mutans streptococci in dental plaque and history of dental visit were significantly correlated with the prevalence of caries and the mean dmfs score. High level of plaque mutans streptococci is a risk factor for ECC in preschool children in Beijing. And longitudinal studies are needed to identify the causal relationships between the levels of mutans streptococci in dental plaque and caries development.

  5. Hyperthyroidism and erectile dysfunction: a population-based case-control study.

    PubMed

    Keller, J; Chen, Y-K; Lin, H-C

    2012-01-01

    Dysthyroidism has been highlighted as a common endocrine disorder associated with erectile dysfunction (ED); however, to date, no large-scale population-based study has investigated the association between hyperthyroidism and ED. This case-control study aimed to explore the association between ED and hyperthyroidism using a population-based data set. In total, 6310 adult patients who received new diagnoses of ED were recruited as cases together with 18 930 matched enrollees with no history of ED who served as controls. Conditional logistic regressions were conducted to explore the association between ED and having been previously diagnosed with hyperthyroidism. In total, 569 (2.3%) of the 25 240 sampled subjects had been diagnosed with hyperthyroidism before the index date; hyperthyroidism was found in 207 (3.3%) cases and 362 (1.90%) controls. After adjusting for potential confounding factors, the odds ratio (OR) of prior hyperthyroidism among cases was 1.64 (95% confidence interval=1.37-1.96, P<0.001) than that of controls. No association was detected between prior hyperthyroidism and ED for the 18-30, 30-39 and >70 age groups. Subjects aged between 60 and 69 years had the highest ORs for prior hyperthyroidism among cases when compared to controls (OR=1.84; 95% confidence interval=1.20-2.84; P<0.001). Our study further confirms the existence of an association between ED and prior hyperthyroidism.

  6. Farmer's lung disease and microbiological composition of hay: a case-control study.

    PubMed

    Roussel, Sandrine; Reboux, Gabriel; Dalphin, Jean-Charles; Pernet, Didier; Laplante, Jean-Jacques; Millon, Laurence; Piarroux, Renaud

    2005-11-01

    Previous studies performed in France have suggested that handling hay contaminated with high amounts of moulds, and especially Absidia corymbifera and Eurotium amstelodami, may favour farmer's lung disease. The circumstances favouring farmer's lung disease and the distinctive microbiological composition of hay samples that provoke attacks need to be specified. We present a case-control study which investigates the agricultural practices and the microbiological composition of hay handled in patients with farmer's lung disease as compared to those of a representative control population. Ten cases identified the hay they were handling at the onset of symptoms. The location, type of farm and working conditions were similar to those of the control farms. Conversely, the microbiological composition of hay differed, with significantly higher amounts of E. amstelodami (P < 0.01), A. corymbifera (P = 0.003), mesophilic Streptomyces (P < 0.01), thermophilic Streptomyces (P < 0.01) and Saccharomonospora viridis (P < 0.01) than in the control population. Our results demonstrate that hay identified by patients as having a harmful effect is characterized by a higher total amount of microorganisms, notably five microorganisms that seem discriminative. Mean concentrations are 2- to 115-fold higher in hay suspected to cause symptoms than in hay from a representative panel of farms. Handling hay with high amounts of these five microorganisms constitutes a risk factor for farmer's lung disease that should be considered for the development of prophylactic measures.

  7. 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

  8. Familial liability, obstetric complications and childhood development abnormalities in early onset schizophrenia: a case control study

    PubMed Central

    2011-01-01

    Background Genetic and environmental risk factors and gene-environment interactions are linked to higher likelihood of developing schizophrenia in accordance with the neurodevelopmental model of disease; little is known about risk factors and early development in early-onset schizophrenia (EOS) and very early-onset schizophrenia (VEOS). Methods We present a case-control study of a sample of 21 patients with EOS/VEOS and a control group of 21 patients with migraine, recruited from the Child Neuropsychiatry Unit, Department of Neurologic and Psychiatric Science, University of Bari, Italy. The aim was to assess the statistical association between VEOS/EOS and family history for psychiatric disorders, obstetric complications and childhood developmental abnormalities using 2 × 2 tables and a Chi Squared or Fisher test. Results The results show a statistical association between EOS/VEOS and schizophrenia and related disorders (P = 0.02) and personality disorders (P = 0.003) in relatives, and between EOS/VEOS and developmental abnormalities of early relational skills (P = 0.008) and learning (P = 0.04); there is not a statistically relevant difference between cases and controls (P > 0.05) for any obstetric complications (pre, peri and postpartum). Conclusions This study confirms the significant role of familial liability but not of obstetric complications in the pathogenesis of VEOS/EOS; the association between childhood developmental abnormalities and EOS/VEOS supports the neurodevelopmental model of disease. PMID:21492438

  9. Retrospective case-control study of viral pathogen screening in proliferative verrucous leukoplakia lesions.

    PubMed

    García-López, R; Moya, A; Bagan, J V; Pérez-Brocal, V

    2014-10-01

    This study aimed to survey the presence of known oncoviruses in oral biopsies from patients diagnosed with the aetiologically undetermined proliferative verrucous leukoplakia and compare results to those from milder oral leukoplakia (OL) cases, oral squamous cell carcinoma, a common outcome of the lesions of interest, and healthy controls. Blind, retrospective, case-control study. A stomatology unit in an academic Hospital and a Public Health laboratory. Forty patients were divided in four groups. Ten patients had been diagnosed with proliferative verrucous leukoplakia, 10 with OL and 10 with OSCC, and 10 were healthy subjects. The presence or absence of oncovirus DNA was assayed with the amplification of viral genetic markers using PCR and subsequent gel electrophoresis confirmation. Amplified fragments were sequenced and identified bioinformatically. No DNA from the herpesvirus, papillomavirus or polyomavirus species was detected in the samples. No association between proliferative verrucous leukoplakia and target viruses was detected. A higher throughput viral metagenomic approach may prove valuable for future analyses, as it would not be restricted to a priori knowledge of potential targets. © 2014 John Wiley & Sons Ltd.

  10. 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

  11. 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

  12. Dermatoglyphic patterns in dementia of the Alzheimer type: a case-control study.

    PubMed Central

    Berr, C; Okra-Podrabinek, N; Feteanu, D; Taurand, S; Hervy, M P; Forette, F; Piette, F; Sebag-Lanoe, R; Alperovitch, A

    1992-01-01

    STUDY OBJECTIVE--The aim was to compare digital and palmar dermatoglyphics in subjects with dementia of Alzheimer type and in mentally healthy elderly controls. DESIGN--This design was a case-control study. SETTING--The study was carried out in geriatric units and retirement communities in the Paris area. PARTICIPANTS--Cases were women with clinically diagnosed Alzheimer type dementia according to DSM III-R criteria (n = 82), mainly with late onset of the disease. Controls were women aged 85 years or older without cognitive deterioration (n = 76). MEASUREMENTS AND MAIN RESULTS--Finger and palm prints obtained from both hands by the classical ink method were examined. Fingerprints were classified into four types of figures. On palms, palmar flexion creases, palmar axial triradii, true patterns of the hypothenar area, and main line terminations were described. Examinations were performed by two examiners blind to the subjects's diagnostic category. For the different patterns studied, no major differences between dementia patients and elderly controls were found. Nor was there evidence of high frequencies of features commonly observed in Down's syndrome (trisomy 21), which have previously, though sporadically, been reported. CONCLUSIONS--On one of the largest samples of Alzheimer dementia patients studied, and with evaluation blind to diagnosis, no evidence has been found that particular dermatoglyphic patterns occur like those observed in Down's syndrome, a disease which is related to dementia of the Alzheimer type. PMID:1479321

  13. Case-Control Study of Injury Intervention for Preschool Children in Henggang, Shenzhen.

    PubMed

    Wang, Hong; Liu, Yi-Xin; Deng, Wen-Jiao; Yang, Wei-Jian; Wang, Fang

    2015-10-01

    To explore effective interventions for child accidental injury prevention and to reduce the incidence of injury. Cluster random sampling method was adopted, and children in 19 kindergartens in Henggang, Shenzhen and their parents were selected as the objects of study. Nineteen kindergartens were randomly divided into intervention group and control group to carry out the injury intervention case-control study. Through a series of interventions, there were certain effects. After the end of the project, the injury incidence rates of the intervention group and the control group were 4.91%, 10.64%, and the difference was significant; the average costs of treatment for injuries of the intervention group and the control group were 168.4 Yuan and 206.8 Yuan, and the difference was statistically significant; compared with before the implementation of the project, the rate of various types of injuries after the end of the project declined, in which, the rate of mechanical injury, pet bites, accidental falls, burns, and traffic accidents decreased significantly. The differences were significant. Injury interventions can effectively prevent and control the occurrence of injury.

  14. Molecular and epidemiological characterization of canine Pseudomonas otitis using a prospective case-control study design.

    PubMed

    Morris, Daniel O; Davis, Meghan F; Palmeiro, Brian S; O'Shea, Kathleen; Rankin, Shelley C

    2017-02-01

    Pseudomonas aeruginosa is an opportunistic pathogen of the canine ear canal and occupies aquatic habitats in the environment. Nosocomial and zoonotic transmission of P. aeruginosa have been documented, including clonal outbreaks. The primary objective of this study was to assess various environmental exposures as potential risk factors for canine Pseudomonas otitis. It was hypothesized that isolates derived from infected ears would be clonal to isolates derived from household water sources and the mouths of human and animal companions of the study subjects. Seventy seven privately owned dogs with otitis were enrolled, along with their human and animal household companions, in a case-control design. Data on potential risk factors for Pseudomonas otitis were collected. Oral cavities of all study subjects, their human and animal companions, and household water sources were sampled. Pulsed field gel electrophoresis was used to estimate clonal relatedness of P. aeruginosa isolates. In a multivariate model, visiting a dog park was associated with 77% increased odds of case status (P = 0.048). Strains clonal to the infection isolates were obtained from subjects' mouths (n = 18), companion pets' mouths (n = 5), pet owners' mouths (n = 2), water bowls (n = 7) and water taps (n = 2). Clonally related P. aeruginosa isolates were obtained from dogs that had no clear epidemiological link. Genetic homology between otic and environmental isolates is consistent with a waterborne source for some dogs, and cross-contamination with other human and animal members within some households. © 2016 ESVD and ACVD.

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

    PubMed Central

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

    2007-01-01

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

  16. Peanut butter intake, GSTM1 genotype and hepatocellular carcinoma: a case-control study in Sudan.

    PubMed

    Omer, R E; Verhoef, L; Van't Veer, P; Idris, M O; Kadaru, A M; Kampman, E; Bunschoten, A; Kok, F J

    2001-01-01

    Hepatocellular carcinoma (HCC) is one of the major cancers in the world. In Sudan the incidence is thought to be high and increasing. This study aims to assess the association between peanut butter intake, as a source of aflatoxins, and the GSTM1 genotype in the etiology of HCC. A case control study was conducted among 150 patients and 205 controls from two regions in Sudan. Food habits with special reference to peanut butter consumption, as well as peanut storage systems, have been investigated, as well as confounders such as hepatitis, drinking and smoking habits, and demographic characteristics. GSTM1 genotype was assessed in DNA extracted from blood samples (110 cases, 189 controls). A positive association was observed for highest vs. lowest quartile of peanut butter intake, humid storage system and HCC, with ORs (95% CI) being 3.0 (1.6-5.5) and 1.6 (1.1-2.5) respectively. The positive association with peanut butter intake was essentially limited to subjects with GSTM1 null genotype with OR for highest vs. lowest quartile 16.7 (2.7-105). Peanut butter consumption has been identified as a strong risk factor of HCC in a region with endemic aflatoxin contamination in Sudan and was essentially limited to subjects with the GSTM1 null genotype.

  17. 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.

  18. Occupational exposures and obstructive lung disease: a case-control study in hairdressers.

    PubMed

    Hashemi, Nastran; Boskabady, Mohammad Hossein; Nazari, Ashraf

    2010-07-01

    Hairdressers are exposed to various irritating chemicals during work. This study was designed as a case-control study to evaluate the risk of developing obstructive lung disease in relation to occupational exposures in hairdressers. We interviewed a cohort of 50 female hairdressers and 50 matched controls recruited from a random sample of the general population, using a validated questionnaire for occupational respiratory disease, to compare the prevalence of work-initiated and work-related respiratory symptoms in both groups. We also performed pulmonary function tests (PFTs) in all participants. Almost half of the hairdressers reported work-initiated respiratory symptoms. Cough (33%) and breathlessness (29%) were the most common self-reported symptoms after chemical exposures. All respiratory symptoms (cough, breathless, wheezing, and phlegm) were significantly higher in the hairdressers than in the control group (P < .001). The hairdressers reported that bleaching powder and hair spray were the most irritant chemicals that provoke their respiratory symptoms. The impaired PFT values (forced vital capacity, FEV(1), maximum mid-expiratory flow, peak expiratory flow) in the hairdressers, compared to the matched controls, were in line with the questionnaire data. Hairdressing work is associated with a high frequency of work-initiated respiratory symptoms and, to a lesser extent, with allergic symptoms, particularly after exposure to bleaching powder and hair spray. PFT values were significantly lower among the hairdressers, which might be a predictor for developing obstructive lung disease.

  19. Caregiver Illness Perception of Their Child’s Early Childhood Caries: A Case-Control Study

    PubMed Central

    Slusar, Mary Beth; Nelson, Suchitra

    2016-01-01

    Purpose This case-control study evaluated the association between parent/caregivers’ illness perception and early childhood caries (ECC). Methods Parent/caregivers of children less than six years old were recruited at the dental clinic of an urban children’s hospital (June 2013-September 2015). Cases were caregivers of children with ECC; controls were caregivers of children without ECC. Caregivers completed the Illness Perception Questionnaire-Revised for Dental (IPQ-RD) assessing cognitive (identity, consequences, control, timeline, illness coherence, cause) and emotional representations of dental caries. Twelve IPQ-RD construct-specific summary scores were calculated; higher scores represented less accurate perception. Logistic regression models examined the relationship between IPQ-RD constructs and ECC. Results The sample included a total of 165 parent/caregivers: 54 (33 percent) of children without ECC; 111 (67 percent) of children with ECC. Two of twelve constructs were related to ECC status. Controlling for caregiver age, education, race/ethnicity and child age, caregivers of children with ECC had less accurate perception of the consequences of dental caries (OR=2.24; 95% CI: 1.07–4.69) and more accurate perception of the controllability of caries (OR=0.29; 95% CI: 0.11–0.76), compared to caregivers of children without ECC. Conclusion Our results suggest that clinicians should emphasize the consequences and controllability of ECC to help caregivers self-manage their child’s oral health. PMID:28206900

  20. Assessment of vitamin K2 levels in osteoporotic patients: a case control study.

    PubMed

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

    2014-07-14

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

  1. Dietary inflammatory index and prostate cancer risk in a case-control study in Mexico.

    PubMed

    Vázquez-Salas, Ruth A; Shivappa, Nitin; Galván-Portillo, Marcia; López-Carrillo, Lizbeth; Hébert, James R; Torres-Sánchez, Luisa

    2016-12-01

    Recent evidence suggests that a pro-inflammatory diet could be associated with prostate cancer (PC) risk. To evaluate the association between dietary inflammatory index (DII) and PC risk as well as aggressiveness, we conducted a case-control study in Mexico City. Cases were 394 individuals with incident, histologically confirmed PC, who were matched by age (±5 years) with 794 population controls. Dietary information was obtained through a semi-quantitative FFQ with a 3-year frame of reference before diagnosis, for cases, or interview, for controls. On the basis of twenty-eight food parameters, we estimated the energy-adjusted DII (E-DII). According to the Gleason score at diagnosis, PC cases were categorised as high (≥8), moderate (=7) and low (≤6) PC risk. Independent, unconditional logistic regression models adjusted for potential confounders were used to estimate PC risk and PC aggressiveness. There were no significant associations between overall PC risk and E-DII (OR3rd v. 1st tertile 1·18; 95 % CI 0·85, 1·63; P=0·33) or among men with high-risk PC (Gleason≥8) (OR 1·46; 95 % CI 0·88, 2·42; P=0·14). These results do not support the hypothesis that a pro-inflammatory diet is related to PC risk and PC aggressiveness. However, further studies with larger sample sizes, with sufficient statistical power and of varying designs should be conducted to address this hypothesis.

  2. Collateral Weight Loss in Children Living with Adult Bariatric Surgery Patients: A Case Control Study

    PubMed Central

    Hirsch, Annemarie G.; Wood, G. Craig; Bailey-Davis, Lisa; Lent, Michelle R.; Gerhard, Glenn S.; Still, Christopher D.

    2014-01-01

    Objective To evaluate the impact of adult bariatric surgery on the Body Mass Index (BMI) of children living in the same household. Design and Methods A retrospective case-control study. Case dyads (n=128) were composed of one adult who had bariatric surgery and one child at the same address. Control dyads (n=384) were composed of an adult with obesity but no bariatric surgery and a child at the same address. We used a two-sample t-test to determine whether the differences between actual and expected BMI at follow-up (post-surgery) differed between children in the case and control dyads. Results Among boys who were overweight, boys who lived with a surgery patient had a lower than expected BMI post-surgery, while boys who did not live with a surgery patient had a higher than expected BMI at follow-up (p=0.045). Differences between actual and expected BMIs of children were not significantly different between cases and controls in girls or in children in other weight classes. Conclusions Overweight boys who lived with an adult bariatric surgery patient had a lower than expected BMI after surgery as compared to controls. Future studies may be warranted to determine the mechanisms by which these children experience collateral weight loss. PMID:24989939

  3. Oral and endotracheal tubes colonization by periodontal bacteria: a case-control ICU study.

    PubMed

    Porto, A N; Cortelli, S C; Borges, A H; Matos, F Z; Aquino, D R; Miranda, T B; Oliveira Costa, F; Aranha, A F; Cortelli, J R

    2016-03-01

    Periodontal infection is a possible risk factor for respiratory disorders; however, no studies have assessed the colonization of periodontal pathogens in endotracheal tubes (ET). This case-control study analyzed whether periodontal pathogens are able to colonize ET of dentate and edentulous patients in intensive care units (ICU) and whether oral and ET periodontal pathogen profiles have any correlation between these patients. We selected 18 dentate and 18 edentulous patients from 78 eligible ICU patients. Oral clinical examination including probing depth, clinical attachment level, gingival index , and plaque index was performed by a single examiner, followed by oral and ET sampling and processing by quantitative polymerase chain reaction (total bacterial load, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythia). Data were statistically analyzed by Mann-Whitney U, two-way analysis of variance (p < 0.05). Among dentate, there was no correlation between clinical parameters and ET bacterial levels. Both dentate and edentulous patients showed similar ET bacterial levels. Dentate patients showed no correlation between oral and ET bacterial levels, while edentulous patients showed positive correlations between oral and ET levels of A. actinomycetemcomitans, P. gingivalis, and T. forsythia. Periodontal pathogens can colonize ET and the oral cavity of ICU patients. Periodontal pathogen profiles tend to be similar between dentate and edentulous ICU patients. In ICU patients, oral cavity represents a source of ET contamination. Although accompanied by higher oral bacterial levels, teeth do not seem to influence ET bacterial profiles.

  4. Familial liability, obstetric complications and childhood development abnormalities in early onset schizophrenia: a case control study.

    PubMed

    Margari, Francesco; Petruzzelli, Maria G; Lecce, Paola A; Todarello, Orlando; De Giacomo, Andrea; Lucarelli, Elisabetta; Martinelli, Domenico; Margari, Lucia

    2011-04-14

    Genetic and environmental risk factors and gene-environment interactions are linked to higher likelihood of developing schizophrenia in accordance with the neurodevelopmental model of disease; little is known about risk factors and early development in early-onset schizophrenia (EOS) and very early-onset schizophrenia (VEOS). We present a case-control study of a sample of 21 patients with EOS/VEOS and a control group of 21 patients with migraine, recruited from the Child Neuropsychiatry Unit, Department of Neurologic and Psychiatric Science, University of Bari, Italy. The aim was to assess the statistical association between VEOS/EOS and family history for psychiatric disorders, obstetric complications and childhood developmental abnormalities using 2 × 2 tables and a Chi Squared or Fisher test. The results show a statistical association between EOS/VEOS and schizophrenia and related disorders (P = 0.02) and personality disorders (P = 0.003) in relatives, and between EOS/VEOS and developmental abnormalities of early relational skills (P = 0.008) and learning (P = 0.04); there is not a statistically relevant difference between cases and controls (P > 0.05) for any obstetric complications (pre, peri and postpartum). This study confirms the significant role of familial liability but not of obstetric complications in the pathogenesis of VEOS/EOS; the association between childhood developmental abnormalities and EOS/VEOS supports the neurodevelopmental model of disease.

  5. Influence of feeding practices on dental caries. A case-control study.

    PubMed

    Bahuguna, R; Younis Khan, S; Jain, A

    2013-03-01

    The aim of this study was to investigate the relationship of feeding practices with dental caries in a group of respondents of 1-18 years of age of Lucknow city, India. A case-control study was carried out in the outpatient department of Paedodontics and Preventive Dental Clinic, Saraswati Dental College and Hospital, Lucknow (UP), India. A total sample of 800 subjects in the 1- 18 years age group was equally divided among cases (DMFT/deft>0) and controls (DMFT/deft = 0). Cases matched with controls for age, sex and religion. Clinical examination (DMFT /deft index) was performed in accordance with the WHO criteria for epidemiological studies. Respondents were interviewed in depth and retrospectively by means of a self- administered questionnaire. Prolonged breast feeding beyond 6 months, bottle feeding, nocturnal bottle feeding containing sweet drink and milk and higher frequency of consumption of sweets emerged as significant risk factors for dental caries. Based on the differences between the caries and non-caries age groups, an educational and preventive programme should be initiated addressing the associated risk factors of specific age groups accordingly. In our present study nocturnal bottle feeding emerged as the most significant risk factor for dental caries in the 1-6 years age group. Hence health professionals should recognise the benefits of breastfeeding up to six months of life and should educate mothers about the importance of implementing beneficial dental habits to ensure that a child reaches oral health.

  6. 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.

  7. Histopathologic features of melanoma in difficult-to-diagnose lesions: A case-control study.

    PubMed

    Gonzalez, Manuel Lora; Young, Eric D; Bush, James; McKenzie, Katelyn; Hunt, Edgar; Tonkovic-Capin, Viseslav; Jacobs, Melissa; Kucenic, Michael; Fraga, Garth R

    2017-09-01

    Dermatopathology is considered the gold standard for melanoma diagnosis, but a subset of cases is difficult to diagnose by histopathology. The goals of this study were to measure the accuracy of histopathologic features in difficult-to-diagnose melanocytic tumors and the interobserver agreement of those features. This is a case-control study of histopathologic features of melanoma in 100 difficult-to-diagnose melanocytic neoplasms (40 melanomas and 60 nevi). Slides were blindly evaluated by 5 dermatopathologists. Frequencies, predictive values, and interobserver agreement were calculated. Univariate and multivariate logistic regression analyses were performed to identify the most influential features in arriving at a diagnosis of melanoma. Asymmetry, single-cell melanocytosis, solar elastosis, pagetoid melanocytosis, and broad surface diameter were most influential in arriving at a diagnosis of melanoma. Asymmetry and single-cell melanocytosis were most predictive of melanoma. Fleiss kappa was <0.6 for interobserver agreement in 9/10 histopathologic features of melanoma. This study is limited by the small sample size, selection bias, and binary classification of melanocytic lesions. Our results indicate histopathologic features of melanoma in difficult-to-diagnose lesions vary in accuracy and reproducibility. Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

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

    PubMed Central

    2016-01-01

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

  9. Laboratory assessment of sudden sensorineural hearing loss: A case-control study.

    PubMed

    Fasano, Tommaso; Pertinhez, Thelma A; Tribi, Lorenzo; Lasagni, Daniela; Pilia, Annalisa; Vecchia, Luigi; Baricchi, Roberto; Bianchin, Giovanni

    2017-10-01

    Sudden sensorineural hearing loss (SSHL) is an otologic emergency that affects five to 30 subjects per 100,000/year. The cause of SSHL remains unknown or uncertain in 70% to 90% of cases, and treatment decisions are usually made without knowing the etiology. Prospective case-control study. One hundred thirty-one idiopathic SSHL patients were recruited from January 2014 to June 2015 in concordance with the Statements of Clinical Practice Guideline and divided into groups according to the disease severity. A clinical laboratory assessment was completed on blood samples collected from SSHL patients and control subjects. Multivariable regression analysis was performed to investigate the association between laboratory data and SSHL basis. Only a few SSHL patients were positive for autoimmunity or viral infection. Statistically significant (P < .05) higher levels of blood glucose, glycated hemoglobin (HbA1C), lipoprotein (a), and factor VIII were found in SSHL patients compared to controls. Furthermore, blood glucose, HbA1C, uric acid, factor VIII, and homocysteine were significantly associated to disease severity. Gluco-metabolic, lipidic, and coagulative laboratory data support the vascular hypothesis for SSHL and its severity. 3b Laryngoscope, 127:2375-2381, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  10. Effects of maternal hypertension on the neonatal haemogram in southern Nigeria: A case-control study.

    PubMed

    Okoye, Helen C; Eweputanna, Lisa I; Korubo, Kaladada I; Ejele, Oseikhuemen A

    2016-12-01

    Hypertension in pregnancy is a leading cause of maternal and neonatal morbidity and mortality. This study aimed to compare the hematological parameters in neonates of hypertensive mothers with those of normotensive mothers, and also to compare the incidence of polycythaemia, neutropenia and thrombocytopenia in both groups. This was a hospital-based case control study. Three milliliters of cord blood from neonates of women with hypertension in pregnancy and those of normotensive pregnant women were sampled for haemogram parameters using a 3-part autoanalyser. Haematocrit and white blood cell differentials were done manually. Data were analysed using SPSS version 16. A total of 200 neonates were recruited, comprising 100 neonates of mothers with hypertensive disorders of pregnancy and 100 neonates of normotensive mothers. The mean haematocrit was significantly higher in neonates of hypertensive mothers than those of normotensive mothers. The neutrophil and platelet counts of neonates of hypertensive mothers were significantly lower than those of normotensive mothers. The incidences of polycythaemia, neutropenia, and thrombocytopenia were found to be 8%, 15%, and 38% among neonates of hypertensive mothers and 0%, 2%, and 8% among neonates of normotensive mothers, respectively. These incidences were significantly different between the groups. There was a positive association between hypertension in pregnancy and neonatal polycythaemia, neutropenia, and thrombocytopenia. Haematological parameters of neonates of mothers with hypertension in pregnancy should be properly evaluated and monitored to reduce the chances of developing complications associated with these abnormalities.

  11. 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.

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

    PubMed

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

    2016-06-22

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

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

    PubMed Central

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

    2016-01-01

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

  14. 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

  15. Association between serum adropin levels and gestational diabetes mellitus; a case-control study.

    PubMed

    Beigi, Aboutaleb; Shirzad, Nooshin; Nikpour, Fatemeh; Nasli Esfahani, Ensieh; Emamgholipour, Solaleh; Bandarian, Fatemeh

    2015-01-01

    Gestational diabetes mellitus (GDM) is increasing worldwide. The aim of this study was to investigate the association between serum adropin concentration and GDM. In a case-control study, conducted in 2013, 40 pregnant women with GDM and 40 healthy pregnant women (controls) were evaluated. Fasting serum adropin and lipid concentration were measured during 24th-28th weeks of gestation for both groups. These factors were compared between the two groups using independent sample t-test. There was a significant difference in adropin levels between the two groups and mean adropin levels were lower in GDM group (p: 0.016). There was no significant correlation between serum adropin levels and body mass index as well as fasting blood glucose (FBS) or serum lipid profile including high-density lipoprotein, low-density lipoprotein, cholesterol and triglyceride concentration (p > 0.05). There was a significant association between adropin concentration and GDM even after using regression model for removing confounding factors (odds ratio = 0.681). Low serum adropin concentration is associated with GDM in Iranian pregnant women.

  16. Work related etiology of de Quervain's tenosynovitis: a case-control study with prospectively collected data.

    PubMed

    Stahl, Stéphane; Vida, Daniel; Meisner, Christoph; Stahl, Adelana Santos; Schaller, Hans-Eberhard; Held, Manuel

    2015-05-28

    The etiology of de Quervain's tenosynovitis (dQ) has been based on conflicting small case series and cohort studies lacking methodological rigor. A prospective case-control study was conducted to analyze the most common risk factors for dQ. Between January 2003 and May 2011, 189 patients surgically treated for dQ vs. 198 patients with wrist ganglia (WG) (controls) were identified in our clinic's electronic database. Sample characteristics, exertional, anatomical, and medical risk factors were compared between groups. dQ vs. WG differed by average age (52 vs. 43 years) and gender ratio (15/62 vs. 26/39). No significant difference between dQ vs. WG was found after subgrouping professional activities (manual labor: 18 % vs. 26 %, respectively, p = 0.23). No asymmetric distribution of comorbidities, wrist trauma, forceful or repetitive manual work, or medication was observed. Neither heavy manual labor nor trauma could be shown to be predisposing risk factors for dQ.

  17. 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

  18. 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

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

    PubMed Central

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

    2014-01-01

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

  20. 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. © 2014 Blackwell Verlag GmbH.

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

    PubMed Central

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

    2017-01-01

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

  2. Case-control study of pathogens involved in piglet diarrhea.

    PubMed

    Ruiz, Vera L A; Bersano, Josete G; Carvalho, Aline F; Catroxo, Márcia H B; Chiebao, Daniela P; Gregori, Fábio; Miyashiro, Simone; Nassar, Alessandra F C; Oliveira, Trícia M F S; Ogata, Renato A; Scarcelli, Eliana P; Tonietti, Paloma O

    2016-01-11

    Diarrhea in piglets directly affects commercial swine production. The disease results from the interaction of pathogens with the host immune system and is also affected by management procedures. Several pathogenic agents such as Campylobacter spp., Clostridium perfringens, Escherichia coli, Salmonella spp., group A rotavirus (RV-A), coronaviruses (transmissible gastroenteritis virus; porcine epidemic diarrhea virus), as well as nematode and protozoan parasites, can be associated with disease cases. All bacterial, viral, protozoan, and parasitic agents here investigated, with the exception of Salmonella spp. as well as both coronaviruses, were detected in varying proportions in piglet fecal samples, and positive animals were equally distributed between case and control groups. A statistically significant difference between case and control groups was found only for Cystoisospora suis (p = 0.034) and Eimeria spp. (p = 0.047). When co-infections were evaluated, a statistically significant difference was found only for C. perfringens β2 and C. suis (p = 0.014). The presence of pathogens in piglets alone does not determine the occurrence of diarrhea episodes. Thus, the indiscriminate use of antibiotic and anthelminthic medication should be re-evaluated. This study also reinforces the importance of laboratory diagnosis and correct interpretation of results as well as the relevance of control and prophylactic measures.

  3. Multi-center MRI prediction models: Predicting sex and illness course in first episode psychosis patients.

    PubMed

    Nieuwenhuis, Mireille; Schnack, Hugo G; van Haren, Neeltje E; Lappin, Julia; Morgan, Craig; Reinders, Antje A; Gutierrez-Tordesillas, Diana; Roiz-Santiañez, Roberto; Schaufelberger, Maristela S; Rosa, Pedro G; Zanetti, Marcus V; Busatto, Geraldo F; Crespo-Facorro, Benedicto; McGorry, Patrick D; Velakoulis, Dennis; Pantelis, Christos; Wood, Stephen J; Kahn, René S; Mourao-Miranda, Janaina; Dazzan, Paola

    2017-01-15

    Structural Magnetic Resonance Imaging (MRI) studies have attempted to use brain measures obtained at the first-episode of psychosis to predict subsequent outcome, with inconsistent results. Thus, there is a real need to validate the utility of brain measures in the prediction of outcome using large datasets, from independent samples, obtained with different protocols and from different MRI scanners. This study had three main aims: 1) to investigate whether structural MRI data from multiple centers can be combined to create a machine-learning model able to predict a strong biological variable like sex; 2) to replicate our previous finding that an MRI scan obtained at first episode significantly predicts subsequent illness course in other independent datasets; and finally, 3) to test whether these datasets can be combined to generate multicenter models with better accuracy in the prediction of illness course. The multi-center sample included brain structural MRI scans from 256 males and 133 females patients with first episode psychosis, acquired in five centers: University Medical Center Utrecht (The Netherlands) (n=67); Institute of Psychiatry, Psychology and Neuroscience, London (United Kingdom) (n=97); University of São Paulo (Brazil) (n=64); University of Cantabria, Santander (Spain) (n=107); and University of Melbourne (Australia) (n=54). All images were acquired on 1.5-Tesla scanners and all centers provided information on illness course during a follow-up period ranging 3 to 7years. We only included in the analyses of outcome prediction patients for whom illness course was categorized as either "continuous" (n=94) or "remitting" (n=118). Using structural brain scans from all centers, sex was predicted with significant accuracy (89%; p<0.001). In the single- or multi-center models, illness course could not be predicted with significant accuracy. However, when reducing heterogeneity by restricting the analyses to male patients only, classification accuracy

  4. 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

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

    PubMed

    Yaseen, Hakam

    2009-03-01

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

  6. 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

  7. Effectiveness of reactive oral cholera vaccination in rural Haiti: a case-control study and bias-indicator analysis.

    PubMed

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

    2015-03-01

    Between April and June, 2012, a reactive cholera vaccination campaign was done in Haiti with an oral inactivated bivalent whole-cell vaccine. We aimed to assess the effectiveness of the vaccine in a case-control study and to assess the likelihood of bias in that study in a bias-indicator study. Residents of Bocozel or Grand Saline who were eligible for the vaccination campaign (ie, age ≥12 months, not pregnant, and living in the region at the time of the vaccine campaign) were included. In the primary case-control study, cases had acute watery diarrhoea, sought treatment at one of three participating cholera treatment units, and had a stool sample positive for cholera by culture. For each case, four control individuals who did not seek treatment for acute watery diarrhoea were matched by location of residence, enrolment time (within 2 weeks of the case), and age (1-4 years, 5-15 years, and >15 years). Cases in the bias-indicator study were individuals with acute watery diarrhoea with a negative stool sample for cholera. Controls were selected in the same manner as in the primary case-control study. Trained staff used standard laboratory procedures to do rapid tests and stool cultures from study cases. Participants were interviewed to collect data on sociodemographic characteristics, risk factors for cholera, and self-reported vaccination. Data were analysed by conditional logistic regression, adjusting for matching factors. From Oct 24, 2012, to March 9, 2014, 114 eligible individuals presented with acute watery diarrhoea and were enrolled, 25 of whom were subsequently excluded. 47 participants were analysed as cases in the vaccine effectiveness case-control study and 42 as cases in the bias-indicator study. 33 (70%) of 47 cholera cases self-reported vaccination versus 167 (89%) of 188 controls (vaccine effectiveness 63%, 95% CI 8-85). 27 (57%) of 47 cases had certified vaccination versus 147 (78%) of 188 controls (vaccine effectiveness 58%, 13-80). Neither self

  8. Assessing different measures of population-level vaccine protection using a case-control study.

    PubMed

    Ali, Mohammad; You, Young Ae; Kanungo, Suman; Manna, Byomkesh; Deen, Jacqueline L; Lopez, Anna Lena; Wierzba, Thomas F; Bhattacharya, Sujit K; Sur, Dipika; Clemens, John D

    2015-11-27

    Case-control studies have not been examined for their utility in assessing population-level vaccine protection in individually randomized trials. We used the data of a randomized, placebo-controlled trial of a cholera vaccine to compare the results of case-control analyses with those of cohort analyses. Cases of cholera were selected from the trial population followed for three years following dosing. For each case, we selected 4 age-matched controls who had not developed cholera. For each case and control, GIS was used to calculate vaccine coverage of individuals in a surrounding "virtual" cluster. Specific selection strategies were used to evaluate the vaccine protective effects. 66,900 out of 108,389 individuals received two doses of the assigned regimen. For direct protection among subjects in low vaccine coverage clusters, we observed 78% (95% CI: 47-91%) protection in a cohort analysis and 84% (95% CI: 60-94%) in case-control analysis after adjusting for confounding factors. Using our GIS-based approach, estimated indirect protection was 52% (95% CI: 10-74%) in cohort and 76% (95% CI: 47-89%) in case control analysis. Estimates of total and overall effectiveness were similar for cohort and case-control analyses. The findings show that case-control analyses of individually randomized vaccine trials may be used to evaluate direct as well as population-level vaccine protection. Copyright © 2015. Published by Elsevier Ltd.

  9. Influence of socioeconomic aspects on lymphatic filariasis: A case-control study in Andhra Pradesh, India.

    PubMed

    Mutheneni, Srinivasa Rao; Upadhyayula, Suryanaryana Murty; Kumaraswamy, Sriram; Kadiri, Madhusudhan Rao; Nagalla, Balakrishna

    2016-01-01

    Lymphatic filariasis (LF) is a major public health problem in India. The objective of the study was to assess the impact of socioeconomic conditions on LF in Chittoor district of Andhra Pradesh, India. A survey was carried out from 2004 to 2007 during which, an epidemiological and socioeconomic data were collected and analysed. The microfilaria (mf) positive samples were taken as cases and matched with control group by sex and age (1:1) for case-control study. Bivariate and multivariate logistic regression was used to identify the potential risk factors for filariasis. Using principal component analysis (PCA), a socioeconomic index was developed and the data/scores were classified into low, medium and high categories. In total 5,133 blood smears were collected, of which 77 samples were found positive for microfilaria (1.52%). Multivariate analysis showed that the risk of filariasis was higher in groups of people with income < ₹1000 per month [OR = 2.752 (95%CI, 0.435-17.429)]; ₹ 1000-3000 per month [3.079 (0.923-0.275)]; people living in tiled house structure [1.641 (0.534-5.048)], with kutcha (uncemented) drainage system [19.427 (2.985- 126.410)], respondents who did not implemented mosquito avoidance measures [1.737 (0.563-5.358)]; and in people who were not aware about prevention and control of filariasis [1.042 (0.368-2.956)]. PCA showed that respondents with low (41.6%) and medium (33.8%) socioeconomic status are more prone to filariasis (p=0.036). The cross sectional study showed that the population with low and medium socioeconomic status are at higher risk of filariasis. The identified socioeconomic risk factors can be used as a guideline for improving the conditions for effective management of filariasis.

  10. Cognitive and neurobiological alterations in electromagnetic hypersensitive patients: results of a case-control study.

    PubMed

    Landgrebe, M; Frick, U; Hauser, S; Langguth, B; Rosner, R; Hajak, G; Eichhammer, P

    2008-12-01

    Hypersensitivity to electromagnetic fields (EMF) is frequently claimed to be linked to a variety of non-specific somatic and neuropsychological complaints. Whereas provocation studies often failed to demonstrate a causal relationship between EMF exposure and symptom formation, recent studies point to a complex interplay of neurophysiological and cognitive alterations contributing to symptom manifestation in electromagnetic hypersensitive patients (EHS). However, these studies have examined only small sample sizes or have focused on selected aspects. Therefore this study examined in the largest sample of EHS EMF-specific cognitive correlates, discrimination ability and neurobiological parameters in order to get further insight into the pathophysiology of electromagnetic hypersensitivity. In a case-control design 89 EHS and 107 age- and gender-matched controls were included in the study. Health status and EMF-specific cognitions were evaluated using standardized questionnaires. Perception thresholds following single transcranial magnetic stimulation (TMS) pulses to the dorsolateral prefrontal cortex were determined using a standardized blinded measurement protocol. Cortical excitability parameters were measured by TMS. Discrimination ability was significantly reduced in EHS (only 40% of the EHS but 60% of the controls felt no sensation under sham stimulation during the complete series), whereas the perception thresholds for real magnetic pulses were comparable in both groups (median 21% versus 24% of maximum pulse intensity). Intra-cortical facilitation was decreased in younger and increased in older EHS. In addition, typical EMF-related cognitions (aspects of rumination, symptom intolerance, vulnerability and stabilizing self-esteem) specifically differentiated EHS from their controls. These results demonstrate significant cognitive and neurobiological alterations pointing to a higher genuine individual vulnerability of electromagnetic hypersensitive patients.

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

    PubMed

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

    2015-06-01

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

  12. Early Pregnancy Sex Steroids and Maternal Breast Cancer: A nested case-control study

    PubMed Central

    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

    2014-01-01

    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. Odds ratios were calculated using conditional logistic regression. Hormone concentrations were not associated with breast cancer overall. Estradiol was positively associated with risk of breast cancer diagnosed age <40 (4th vs. 1st quartile OR 1.60 (1.07–2.39); ptrend=0.01), and inversely associated with breast cancer diagnosed at age ≥40 (4th vs. 1st quartile OR 0.71 (0.51–1.00); ptrend=0.02). Elevated concentrations of the steroid hormones were associated with increased risk of estrogen receptor (ER) and progesterone receptor (PR) negative tumors in women age <40 at diagnosis. We observed no association between steroid hormones and ER+/PR+ disease. These data suggest a positive association between high concentrations of early pregnancy steroid hormones and risk of ER−/PR− breast cancer in women diagnosed age <40, and an inverse association for overall breast cancer diagnosed age ≥40. Further research on pregnancy hormones and risk of steroid receptor negative cancers is needed to further characterize this association. PMID:25281720

  13. Early pregnancy sex steroids and maternal breast cancer: a nested case-control study.

    PubMed

    Fortner, Renée T; Schock, Helena; Kaaks, Rudolf; Lehtinen, Matti; Pukkala, Eero; Lakso, Hans-Åke; Tanner, Minna; Kallio, Raija; Joensuu, Heikki; Grankvist, Kjell; Zeleniuch-Jacquotte, Anne; Toniolo, Paolo; Lundin, Eva; Surcel, Helja-Marja

    2014-12-01

    Pregnancy, parity, and circulating steroid hormone levels are associated with risk of breast cancer, but little is known about hormone concentrations during pregnancy and subsequent breast cancer risk. We evaluated early pregnancy (<140 days gestation) serum estradiol, estrone, progesterone, and testosterone and breast cancer risk in a nested case-control study in the Finnish Maternity Cohort. The cohort includes 98% of pregnancies registered in Finland since 1983. Individuals with samples collected in the first pregnancy leading to a live birth were eligible. Breast cancer cases (n = 1,199) were identified through linkage with the Finnish Cancer Registry; 2,281 matched controls were selected using incidence density sampling. ORs were calculated using conditional logistic regression. Hormone concentrations were not associated with breast cancer overall. Estradiol was positively associated with risk of breast cancer diagnosed age <40 [4th vs. 1st quartile OR 1.60 (1.07-2.39); Ptrend = 0.01], and inversely associated with breast cancer diagnosed at age ≥40 [4th vs. 1st quartile OR 0.71 (0.51-1.00); Ptrend = 0.02]. Elevated concentrations of the steroid hormones were associated with increased risk of estrogen receptor (ER)- and progesterone receptor (PR)-negative tumors in women age <40 at diagnosis. We observed no association between steroid hormones and ER(+)/PR(+) disease. These data suggest a positive association between high concentrations of early pregnancy steroid hormones and risk of ER(-)/PR(-) breast cancer in women diagnosed age <40, and an inverse association for overall breast cancer diagnosed age ≥40. Further research on pregnancy hormones and risk of steroid receptor-negative cancers is needed to further characterize this association.

  14. 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

  15. Human papillomavirus infection and spontaneous abortion: a case-control study performed in Mexico.

    PubMed

    Conde-Ferráez, Laura; Chan May, Alberto de A; Carrillo-Martínez, Jorge R; Ayora-Talavera, Guadalupe; González-Losa, María del Refugio

    2013-10-01

    To investigate if HPV cervical infection is associated with spontaneous abortion in a Mexican population. Case control study including 281 women from two Social Security Hospitals in Merida, Mexico. Cases were women with spontaneous abortion attending for curettage, and controls were pregnant women at term who attended for delivery. HPV molecular detection and typing of HPV 16, 18, 58 and 6/11 was performed on cervical samples, and TORCH serology IgM tests (against T. gondii, CMV, HSV) were performed on cases. Data were analyzed using Chi square, odds ratio and linear regression tests. HPV global prevalence was 19.8% (24.4% in cases and 15.2% in controls). HPV types 16 and 58 were the most frequently detected in both groups. Multiple HPV types concurrent infection were found in 31.4% of typified samples. Amongst cases 27.3% of HPV positive women reported at least one previous pregnancy loss; compared to 17.43% amongst HPV negative women. Nevertheless, HPV was not significantly associated with spontaneous or to repetitive abortion. Cases were 60.2% positive to any TORCH agent, although it was not significantly associated to referred miscarriage history. Spontaneous abortion was associated to a previous pregnancy loss and to women's age older than 35 years old. HPV infection was significantly associated to alcohol intake before pregnancy and to multiple sexual partners. HPV cervical infection was not associated with spontaneous abortion. HPV in spontaneous abortion and other adverse pregnancy outcomes merits further study. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  16. 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

  17. 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

  18. Brain anatomy and its relationship to behavior in adults with autism spectrum disorder: a multicenter magnetic resonance imaging study.

    PubMed

    Ecker, Christine; Suckling, John; Deoni, Sean C; Lombardo, Michael V; Bullmore, Ed T; Baron-Cohen, Simon; Catani, Marco; Jezzard, Peter; Barnes, Anna; Bailey, Anthony J; Williams, Steven C; Murphy, Declan G M

    2012-02-01

    There is consensus that autism spectrum disorder (ASD) is accompanied by differences in neuroanatomy. However, the neural substrates of ASD during adulthood, as well as how these relate to behavioral variation, remain poorly understood. To identify brain regions and systems associated with ASD in a large, well-characterized sample of adults. Multicenter case-control design using quantitative magnetic resonance imaging. Medical Research Council UK Autism Imaging Multicentre Study (MRC AIMS), with sites comprising the Institute of Psychiatry, Kings College London; the Autism Research Centre, University of Cambridge; and the Autism Research Group, University of Oxford. Eighty-nine men with ASD and 89 male control participants who did not differ significantly in mean age (26 and 28 years, respectively) and full-scale IQ (110 and 113, respectively). (1) Between-group differences in regional neuroanatomy assessed by voxel-based morphometry and (2) distributed neural systems maximally correlated with ASD, as identified by partial least-squares analysis. Adults with ASD did not differ significantly from the controls in overall brain volume, confirming the results of smaller studies of individuals in this age group without intellectual disability. However, voxelwise comparison between groups revealed that individuals with ASD had significantly increased gray matter volume in the anterior temporal and dorsolateral prefrontal regions and significant reductions in the occipital and medial parietal regions compared with controls. These regional differences in neuroanatomy were significantly correlated with the severity of specific autistic symptoms. The large-scale neuroanatomic networks maximally correlated with ASD identified by partial least-squares analysis included the regions identified by voxel-based analysis, as well as the cerebellum, basal ganglia, amygdala, inferior parietal lobe, cingulate cortex, and various medial, orbital, and lateral prefrontal regions. We also

  19. Environmental exposure to Toxocara as a possible risk factor for asthma: a clinic-based case-control study.

    PubMed

    Sharghi, N; Schantz, P M; Caramico, L; Ballas, K; Teague, B A; Hotez, P J

    2001-04-01

    The zoonotic ascarid Toxocara has been suggested as a possible etiologic agent of asthma. We conducted a clinic-based case-control study to examine whether the zoonotic infection acquired by ingesting Toxocara eggs is associated with asthma in children. Blood samples were collected from children aged 2-15 years, 95 of whom had asthma and 229 of whom did not have asthma. Risk factors for asthma and Toxocara infection were assessed by a questionnaire given to each child's parent or legal guardian. Blood samples were tested for the presence of Toxocara antibodies, using an enzyme-linked immunosorbent assay. No significant association was found between Toxocara infection and asthma. Significant associations were found between asthma and risk factors and between Toxocara infection and risk factors. High prevalence of Toxocara infection was noted among Hispanic children of Puerto Rican descent.

  20. 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,