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Sample records for helios-i multicenter case-control

  1. 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

  2. 77 FR 12598 - Notice Correction; A Multi-Center International Hospital-Based Case-Control Study of Lymphoma in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-01

    ...-Based Case-Control Study of Lymphoma in Asia (AsiaLymph) (NCI) The Federal Register notice published on February 24, 2012 (77 FR 11136) announcing the submission to OMB of the project titled, ``A multi-center international hospital-based case-control study of lymphoma in Asia (AsiaLymph) (NCI)'' was submitted with...

  3. 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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2001-01-01

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

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

    PubMed

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

    1991-07-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  11. 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

  12. 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

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

    PubMed

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

    2015-12-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2014-10-01

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

  16. 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

  17. 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

  18. 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

  19. Designing case-control studies.

    PubMed Central

    Yanagawa, T

    1979-01-01

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

  20. 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…

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2016-04-10

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

  3. 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

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

    PubMed

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

    2016-06-15

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

  5. 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

  6. 77 FR 11136 - Proposed Collection; Comment Request; a Multi-Center International Hospital-Based Case-Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

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

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

    PubMed Central

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

    2015-01-01

    Outdoor air pollution is increasingly considered as a serious threat for cardiovascular diseases (CVD). The aim of this study is to investigate the association between outdoor pollutants and cardiovascular diseases among adults in Lebanon and to examine the possible moderator effect of cigarette smoking status on this association. A multicenter case-control study was conducted between October 2011 and October 2012. Cases were hospitalized patients diagnosed with CVD by a cardiologist while the control group subjects were free of any cardiac diseases. Information on sociodemographic characteristics, tobacco consumption, self-rated global health, pollution exposure, and other risk factors was collected using a questionnaire. The results of the logistic regression revealed that living near busy highway (OR 5.04, 95% CI (4.44–12.85), P < 0.001) and close to local diesel generator (OR 4.76, 95% CI (2.07–10.91), P < 0.001) was significantly associated with CVD. The association between the CVD and exposure to outside pollutants differed by cigarette smoking status. A clear difference was noted between nonsmokers and current smokers OR 4.6, 95% CI (1.10–19.25) and OR 10.11, 95% CI (7.33–20.23), respectively. Forthcoming studies are needed to clarify the potential link between outdoor air pollution and cardiovascular diseases in Lebanon. Public health interventions must be implemented to reduce air pollution and to improve air quality. PMID:25653681

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

    PubMed

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

    2015-01-01

    Outdoor air pollution is increasingly considered as a serious threat for cardiovascular diseases (CVD). The aim of this study is to investigate the association between outdoor pollutants and cardiovascular diseases among adults in Lebanon and to examine the possible moderator effect of cigarette smoking status on this association. A multicenter case-control study was conducted between October 2011 and October 2012. Cases were hospitalized patients diagnosed with CVD by a cardiologist while the control group subjects were free of any cardiac diseases. Information on sociodemographic characteristics, tobacco consumption, self-rated global health, pollution exposure, and other risk factors was collected using a questionnaire. The results of the logistic regression revealed that living near busy highway (OR 5.04, 95% CI (4.44-12.85), P < 0.001) and close to local diesel generator (OR 4.76, 95% CI (2.07-10.91), P < 0.001) was significantly associated with CVD. The association between the CVD and exposure to outside pollutants differed by cigarette smoking status. A clear difference was noted between nonsmokers and current smokers OR 4.6, 95% CI (1.10-19.25) and OR 10.11, 95% CI (7.33-20.23), respectively. Forthcoming studies are needed to clarify the potential link between outdoor air pollution and cardiovascular diseases in Lebanon. Public health interventions must be implemented to reduce air pollution and to improve air quality. PMID:25653681

  9. Multicenter breast cancer collaborative registry.

    PubMed

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

    2011-01-01

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

  10. 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

  11. Multicenter Guidelines | Division of Cancer Prevention

    Cancer.gov

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  14. 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.

  15. On combining family and case-control studies.

    PubMed

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

    2008-11-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed

    Setia, Maninder Singh

    2016-01-01

    Case-Control study design is a type of observational study. In this design, participants are selected for the study based on their outcome status. Thus, some participants have the outcome of interest (referred to as cases), whereas others do not have the outcome of interest (referred to as controls). The investigator then assesses the exposure in both these groups. The investigator should define the cases as specifically as possible. Sometimes, definition of a disease may be based on multiple criteria; thus, all these points should be explicitly stated in case definition. An important aspect of selecting a control is that they should be from the same 'study base' as that of the cases. We can select controls from a variety of groups. Some of them are: General population; relatives or friends; and hospital patients. Matching is often used in case-control control studies to ensure that the cases and controls are similar in certain characteristics, and it is a useful technique to increase the efficiency of the study. Case-Control studies can usually be conducted relatively faster and are inexpensive - particularly when compared with cohort studies (prospective). It is useful to study rare outcomes and outcomes with long latent periods. This design is not very useful to study rare exposures. Furthermore, they may also be prone to certain biases - selection bias and recall bias. PMID:27057012

  18. Methodology Series Module 2: Case-control Studies

    PubMed Central

    Setia, Maninder Singh

    2016-01-01

    Case-Control study design is a type of observational study. In this design, participants are selected for the study based on their outcome status. Thus, some participants have the outcome of interest (referred to as cases), whereas others do not have the outcome of interest (referred to as controls). The investigator then assesses the exposure in both these groups. The investigator should define the cases as specifically as possible. Sometimes, definition of a disease may be based on multiple criteria; thus, all these points should be explicitly stated in case definition. An important aspect of selecting a control is that they should be from the same ‘study base’ as that of the cases. We can select controls from a variety of groups. Some of them are: General population; relatives or friends; and hospital patients. Matching is often used in case-control control studies to ensure that the cases and controls are similar in certain characteristics, and it is a useful technique to increase the efficiency of the study. Case-Control studies can usually be conducted relatively faster and are inexpensive – particularly when compared with cohort studies (prospective). It is useful to study rare outcomes and outcomes with long latent periods. This design is not very useful to study rare exposures. Furthermore, they may also be prone to certain biases – selection bias and recall bias. PMID:27057012

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

    PubMed Central

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

    2005-01-01

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

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

    PubMed

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

    1985-08-01

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

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

    PubMed

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

    2010-11-01

    Following favourable results from a previous study, a large, multicentre, prospective, case-control study was performed to further assess the incidence of bleeding complications after dental extraction in patients taking oral anticoagulant therapy (OAT). Four hundred fifty-one patients being treated with warfarin who required dental extraction were compared with a control group of 449 non-anticoagulated subjects undergoing the same procedure. In the warfarin-treated group, the oral anticoagulant regimen was maintained unchanged, such that the patients had an International Normalised Ratio ranging between 1.8 and 4, and local haemostatic measures (i.e. fibrin sponges, silk sutures and gauzes saturated with tranexamic acid) were adopted. All the procedures were performed in an outpatient setting. Seven bleeding complications occurred in the OAT group and four in the control group; the difference in the number of bleeding events between the two groups was not statistically significant (OR=1.754; 95% CI 0.510 - 6.034; p=0.3727). No post-operative late bleeds requiring hospitalisation and/or blood transfusions were recorded, and the adjunctive local haemostatic measures were adequate to stop the bleeding. The results of our protocol applied in this large, multicenter study show that dental extractions can be performed easily and safely in anticoagulated outpatients without any modification of the ongoing anticoagulant therapy, thus minimising costs and reducing discomfort for patients. PMID:20806110

  2. 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

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

    PubMed

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

    2011-09-01

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

  4. Dose-response in case-control studies.

    PubMed Central

    Berry, G

    1980-01-01

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

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

    PubMed

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

    1982-02-01

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

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

    PubMed

    Chu, Rong; Gustafson, Paul; Le, Nhu

    2010-04-30

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

  7. 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.

  8. 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

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

    PubMed

    Lee, Wen-Chung

    2004-07-01

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

  10. 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

  11. 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

  12. 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

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

    PubMed

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

    2007-06-01

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

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

    SciTech Connect

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

    1987-01-01

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

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

    PubMed

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

    2016-05-01

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

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

    PubMed Central

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

    2007-01-01

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

  18. 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

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

    PubMed

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

    2013-12-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed Central

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

    1995-01-01

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

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

    PubMed

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

    2010-01-01

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

  3. 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

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

    PubMed Central

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

    2011-01-01

    Demodex has been considered to be related with multiple skin disorders, but controversy persists. In this case-control study, a survey was conducted with 860 dermatosis patients aged 12 to 84 years in Xi’an, China to identify the association between facial dermatosis and Demodex. Amongst the patients, 539 suffered from facial dermatosis and 321 suffered from non-facial dermatosis. Demodex mites were sampled and examined using the skin pressurization method. Multivariate regression analysis was applied to analyze the association between facial dermatosis and Demodex infestation, and to identify the risk factors of Demodex infestation. The results showed that total detection rate of Demodex was 43.0%. Patients aged above 30 years had higher odds of Demodex infestation than those under 30 years. Compared to patients with neutral skin, patients with mixed, oily, or dry skin were more likely to be infested with Demodex (odds ratios (ORs) were 2.5, 2.4, and 1.6, respectively). Moreover, Demodex infestation was found to be statistically associated with rosacea (OR=8.1), steroid-induced dermatitis (OR=2.7), seborrheic dermatitis (OR=2.2), and primary irritation dermatitis (OR=2.1). In particular, ORs calculated from the severe infestation (≥5 mites/cm2) rate were significantly higher than those of the total rate. Therefore, we concluded that Demodex is associated with rosacea, steroid-induced dermatitis, seborrheic dermatitis, and primary irritation dermatitis. The rate of severe infestation is found to be more correlated with various dermatosis than the total infestation rate. The risk factors of Demodex infestation, age, and skin types were identified. Our study also suggested that good hygiene practice might reduce the chances of demodicosis and Demodex infestation. PMID:22135150

  5. 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

  6. 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

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

    PubMed Central

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

    2008-01-01

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

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

    PubMed

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

    2014-10-01

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

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

    PubMed

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

    2002-06-01

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

  10. 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

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

    PubMed

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

    2002-05-01

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

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

    PubMed

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

    2015-11-01

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

  13. Lessons from Korean Capsule Endoscopy Multicenter Studies

    PubMed Central

    Kim, Kyeong Ok

    2012-01-01

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

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

    PubMed

    Pandey, M; Shukla, V K

    2002-08-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  17. Multicenter pediatric emergency medicine research and Rhode Island.

    PubMed

    Chun, Thomas H

    2014-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  19. 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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2012-01-01

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

  2. Infliximab-induced autoantibodies: a multicenter study.

    PubMed

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

    2016-02-01

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

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

    PubMed

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

    2015-06-01

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

  4. 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

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

    PubMed

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

    2007-11-15

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

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

    PubMed

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

    2011-01-01

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

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

    PubMed

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

    2010-03-01

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

  8. 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

  9. 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

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

    PubMed

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

    2002-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    ERIC Educational Resources Information Center

    McGraw, Sarah A.; And Others

    1994-01-01

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

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

    ERIC Educational Resources Information Center

    Stretesky, Paul B.

    2009-01-01

    The purpose of this study is to examine the relationship between methamphetamine use and homicide. To carry out this study, data from the National Household Survey on Drug Abuse and Survey of Inmates in State and Federal Correctional Facilities were combined to create a case-control design. The main exposure measure is methamphetamine use and the…

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

    ERIC Educational Resources Information Center

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

    2011-01-01

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

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

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

    PubMed Central

    Kim, Ryung S.; Kaplan, Robert C.

    2014-01-01

    One of the main perceived advantages of using a case-cohort design compared to a nested case-control design in an epidemiologic study is the ability to evaluate with the same subcohort outcomes other than the primary outcome of interest. In this paper, we show that valid inferences about secondary outcomes can also be achieved in nested case-control studies by using the inclusion probability weighting method originally proposed by Samuelsen (1997) in combination with an approximate jackknife standard error that can be computed using existing software. Simulation studies demonstrate that when the sample size is sufficient, this approach yields valid type 1 error and coverage rates for the analysis of secondary outcomes in nested case-control designs. Interestingly, the statistical power of the nested case-control design was comparable to that of the case-cohort design when the primary and secondary outcomes were positively correlated. The proposed method is illustrated with data from a cohort in Cardiovascular Health Study to study the association of C-reactive protein levels and the incidence of congestive heart failure. PMID:24919979

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

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

    ERIC Educational Resources Information Center

    Baker, David; Green, Lucy

    2013-01-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    ERIC Educational Resources Information Center

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

    2010-01-01

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

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

    EPA Science Inventory

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

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

    ERIC Educational Resources Information Center

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

    2015-01-01

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

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

    PubMed

    Marshall, J; Graham, S; Swanson, M

    1982-06-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2016-05-01

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

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

    PubMed

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

    2011-02-01

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

  11. Multicentered black holes with a negative cosmological constant

    NASA Astrophysics Data System (ADS)

    Chimento, Samuele; Klemm, Dietmar

    2014-01-01

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

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

    PubMed

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

    2013-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2016-06-01

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

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

    SciTech Connect

    Brownson, R.C.

    1988-05-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2011-09-01

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

  1. 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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2016-05-15

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

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

    PubMed

    Lane, D A; Kramer, M S

    1999-12-01

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

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

    PubMed

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

    2009-08-01

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

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

    PubMed

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

    1998-03-01

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

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

    PubMed Central

    Likosky, Donald S.

    2009-01-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2004-12-01

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

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

    PubMed Central

    2013-01-01

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

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

    SciTech Connect

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

    2010-12-14

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

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

    PubMed Central

    2006-01-01

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

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

    PubMed

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

    2015-01-15

    Bricklayers may be exposed to several lung carcinogens, including crystalline silica and asbestos. Previous studies that analyzed lung cancer risk among these workers had several study design limitations. We examined lung cancer risk among bricklayers within SYNERGY, a large international pooled analysis of case-control studies on lung cancer and the joint effects of occupational carcinogens. For men ever employed as bricklayers we estimated odds ratios (OR) and 95% confidence intervals (CI) adjusted for study center, age, lifetime smoking history and employment in occupations with exposures to known or suspected lung carcinogens. Among 15,608 cases and 18,531 controls, there were 695 cases and 469 controls who had ever worked as bricklayers (OR: 1.47; 95% CI: 1.28-1.68). In studies using population controls the OR was 1.55 (95% CI: 1.32-1.81, 540/349 cases/controls), while it was 1.24 (95% CI: 0.93-1.64, 155/120 cases/controls) in hospital-based studies. There was a clear positive trend with length of employment (p < 0.001). The relative risk was higher for squamous (OR: 1.68, 95% CI: 1.42-1.98, 309 cases) and small cell carcinomas (OR: 1.78, 95% CI: 1.44-2.20, 140 cases), than for adenocarcinoma (OR: 1.17, 95% CI: 0.95-1.43, 150 cases) (p-homogeneity: 0.0007). ORs were still elevated after additional adjustment for education and in analyses using blue collar workers as referents. This study provided robust evidence of increased lung cancer risk in bricklayers. Although non-causal explanations cannot be completely ruled out, the association is plausible in view of the potential for exposure to several carcinogens, notably crystalline silica and to a lesser extent asbestos. PMID:24861979

  14. 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

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

    PubMed

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

    2015-01-01

    Older adults are underrepresented in medical research for many reasons, including recruitment difficulties. Recruitment of older adults for research studies is often a time-consuming process and can be more challenging when the study involves older adults with unique exposures to traumatic events and from minority groups. The current article provides a brief overview of (a) challenges encountered while recruiting aging women Holocaust survivors for a case control study and (b) strategies used for meeting those challenges. The case group comprised women Holocaust survivors who were recently diagnosed with breast cancer and the control group comprised healthy women from a Holocaust-survivor community in Israel. PMID:26020580

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

    PubMed

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

    2015-08-01

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

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

    PubMed Central

    Young, B; Briscoe, J

    1988-01-01

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

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

    PubMed

    Young, B; Briscoe, J

    1988-03-01

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

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

    PubMed

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

    1997-06-01

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

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

    PubMed

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

    2005-06-01

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

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

    PubMed Central

    Hardell, L.; Sandström, A.

    1979-01-01

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

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

    PubMed

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

    2007-01-01

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

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

    PubMed

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

    2006-02-01

    The killing of women by men who then take their own lives (femicide-suicide) is the most common form of homicide-suicide. This study identified femicide-suicide risk factors in an 11-city case-control study of femicide in the United States. Perpetrator, victim, relationship, and incident characteristics were analyzed for femicide-suicide cases (n = 67) and controls (n = 356, women living in the community with nonfatal physical abuse) using logistic regression modeling. Two risk factors emerged that were unique to femicide-suicides cases compared to overall femicide risk analyses: prior perpetrator suicide threats and victims having ever been married to the perpetrator. PMID:16494130

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

    PubMed

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

    1989-10-01

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

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

    SciTech Connect

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

    1988-12-01

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

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

    SciTech Connect

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

    1984-06-01

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

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

    PubMed

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

    1994-12-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed Central

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

    2004-01-01

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

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

    SciTech Connect

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

    1984-04-01

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

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

    PubMed

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

    1998-09-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

    Wang, Zuoheng

    2011-01-01

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

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

    PubMed Central

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

    2002-01-01

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

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

    PubMed Central

    Morabia, Alfredo

    2013-01-01

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

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

    PubMed

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

    2015-06-01

    Successful investigation of national outbreaks of communicable disease relies on rapid identification of the source. Case-control methodologies are commonly used to achieve this. We assessed control selection methods used in recently published case-control studies for methodological and resource issues to determine if a standard approach could be identified. Neighbourhood controls were the most frequently used method in 53 studies of a range of different sizes, infections and settings. The most commonly used method of data collection was face to face interview. Control selection issues were identified in four areas: method of identification of controls, appropriateness of controls, ease of recruitment of controls, and resource requirements. Potential biases arising from the method of control selection were identified in half of the studies assessed. There is a need to develop new ways of selecting controls in a rapid, random and representative manner to improve the accuracy and timeliness of epidemiological investigations and maximise the effectiveness of public health interventions. Innovative methods such as prior recruitment of controls could improve timeliness and representativeness of control selection. PMID:25762171

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

    SciTech Connect

    Ocasio-Alvarex, A.

    1988-01-01

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

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

    PubMed

    Morabia, Alfredo

    2013-12-15

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-03-01

    Case-control studies of sporadic Campylobacter infections have predominately been conducted in non-Hispanic populations. In Arizona, rates of campylobacteriosis have been historically higher than the national average, with particularly high rates in Hispanics. In 2010, health departments and a state university collaborated to conduct a statewide case-control study to determine whether risk factors differ in an ethnically diverse region of the United States. Statistically significant risk factors in the final multivariate model were: eating cantaloupe [odds ratio (OR) 7·64], handling raw poultry (OR 4·88) and eating queso fresco (OR 7·11). In addition, compared to non-Hispanic/non-travellers, the highest risk group were Hispanic/non-travellers (OR 7·27), and Hispanic/travellers (OR 5·87, not significant). Results of this study suggest Hispanics have higher odds of disease, probably due to differential exposures. In addition to common risk factors, consumption of cantaloupe was identified as a significant risk factor. These results will inform public health officials of the varying risk factors for Campylobacter in this region. PMID:26828241

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

    PubMed Central

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

    2005-01-01

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

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

    SciTech Connect

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

    1996-12-01

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

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

    PubMed

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

    2007-07-01

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

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

    PubMed

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

    2005-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    1999-01-01

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

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

    PubMed

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

    2016-06-01

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

  8. 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

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

    PubMed

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

    2014-12-01

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

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

    PubMed

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

    1994-11-01

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

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

    PubMed

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

    2005-09-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2011-01-01

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

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

    PubMed

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

    2004-08-10

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

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

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

    PubMed

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

    2003-01-01

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

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

    SciTech Connect

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

    1987-02-01

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

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

    PubMed

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

    2011-01-01

    In this case control study, the risk factors of lung cancer was assessed in the north of Iran. Two groups were matched for gender and age (+/- 5 years). Data were collected from 40 cases and 40 controls attending to hospitals. A public information questionnaire was used for data collection. Incidence odds ratios (OR) and corresponding 95% confidence intervals calculated using logistic regression analyses. Results showed that in adjusted odd ratio positive family history of cancer (OR = 0/19, 95% CI: 0/04-0/8) was associated with a reduction, and consumption of baked bread in traditional oven (OR = 22/6, 95% CI: 1/9-270), was associated with increase in lung cancer risk. Based on the results, smoking was not correlated with lung cancer. In conclusion, the data offers consumption of traditional oven-baked bread may enhance the risk of lung cancer but positive family history of cancer may reduce it. PMID:21699022

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

    PubMed

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

    1992-09-01

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

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

    PubMed

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

    2014-03-01

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

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

    PubMed Central

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

    1989-01-01

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

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

    PubMed Central

    Shahar, Eyal; Shahar, Doron J

    2012-01-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    SciTech Connect

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

    1985-08-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    SciTech Connect

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

    1980-07-01

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

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

    PubMed Central

    Damber, L A; Larsson, L G

    1987-01-01

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

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

    PubMed

    Vannasaeng, S; Nitiyanant, W; Vichayanrat, A

    1988-12-01

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

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

    PubMed Central

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

    2009-01-01

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

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

    PubMed

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

    2016-09-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

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

    PubMed Central

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

    1988-01-01

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

  13. Multicenter mapping of structural network alterations in autism.

    PubMed

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

    2015-06-01

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

  14. Multicenter clinical trial using next-generation Internet technology

    NASA Astrophysics Data System (ADS)

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

    2001-08-01

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

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

    PubMed Central

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

    2010-01-01

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

  16. Mycobacterium tuberculosis Pyrazinamide Resistance Determinants: a Multicenter Study

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2016-05-01

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

  18. 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

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

    PubMed

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

    1984-04-01

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

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

    PubMed Central

    James, David

    2010-01-01

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

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

    PubMed

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

    2010-04-01

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

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

    PubMed

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

    2015-04-01

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

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

    PubMed Central

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

    2014-01-01

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

  4. 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

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

    PubMed

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

    2015-08-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2007-08-01

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

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

    PubMed

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

    2014-09-01

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

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

    PubMed Central

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

    2005-01-01

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

  12. 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

  13. Stevens-Johnson Syndrome Associated with Drugs and Vaccines in Children: A Case-Control Study

    PubMed Central

    Raucci, Umberto; Rossi, Rossella; Da Cas, Roberto; Rafaniello, Concita; Mores, Nadia; Bersani, Giulia; Reale, Antonino; Pirozzi, Nicola; Menniti-Ippolito, Francesca; Traversa, Giuseppe; in Drug and Children, Italian Multicenter Study Group for Vaccine Safety

    2013-01-01

    Objective Stevens-Johnson Syndrome (SJS) is one of the most severe muco-cutaneous diseases and its occurrence is often attributed to drug use. The aim of the present study is to quantify the risk of SJS in association with drug and vaccine use in children. Methods A multicenter surveillance of children hospitalized through the emergency departments for acute conditions of interest is currently ongoing in Italy. Cases with a diagnosis of SJS were retrieved from all admissions. Parents were interviewed on child’s use of drugs and vaccines preceding the onset of symptoms that led to the hospitalization. We compared the use of drugs and vaccines in cases with the corresponding use in a control group of children hospitalized for acute neurological conditions. Results Twenty-nine children with a diagnosis of SJS and 1,362 with neurological disorders were hospitalized between 1st November 1999 and 31st October 2012. Cases were more frequently exposed to drugs (79% vs 58% in the control group; adjusted OR 2.4; 95% CI 1.0–6.1). Anticonvulsants presented the highest adjusted OR: 26.8 (95% CI 8.4–86.0). Significantly elevated risks were also estimated for antibiotics use (adjusted OR 3.3; 95% CI 1.5–7.2), corticosteroids (adjusted OR 4.2; 95% CI 1.8–9.9) and paracetamol (adjusted OR 3.2; 95% CI 1.5–6.9). No increased risk was estimated for vaccines (adjusted OR: 0.9; 95% CI 0.3–2.8). Discussion Our study provides additional evidence on the etiologic role of drugs and vaccines in the occurrence of SJS in children. PMID:23874553

  14. The Relationship Between Distance to Water Source and Moderate-to-Severe Diarrhea in the Global Enterics Multi-Center Study in Kenya, 2008-2011.

    PubMed

    Nygren, Benjamin L; O'Reilly, Ciara E; Rajasingham, Anangu; Omore, Richard; Ombok, Maurice; Awuor, Alex O; Jaron, Peter; Moke, Fenny; Vulule, John; Laserson, Kayla; Farag, Tamer H; Nasrin, Dilruba; Nataro, James P; Kotloff, Karen L; Levine, Myron M; Derado, Gordana; Ayers, Tracy L; Lash, R Ryan; Breiman, Robert F; Mintz, Eric D

    2016-05-01

    In the developing world, fetching water for drinking and other household uses is a substantial burden that affects water quantity and quality in the household. We used logistic regression to examine whether reported household water fetching times were a risk factor for moderate-to-severe diarrhea (MSD) using case-control data of 3,359 households from the Global Enterics Multi-Center Study in Kenya in 2009-2011. We collected additional global positioning system (GPS) data for a subset of 254 randomly selected households and compared GPS-based straight line and actual travel path distances to fetching times reported by respondents. GPS-based data were highly correlated with respondent-provided times (Spearman correlation coefficient = 0.81, P < 0.0001). The median estimated one-way distance to water source was 200 m for cases and 171 for controls (Wilcoxon rank sums/Mann-Whitney P = 0.21). A round-trip fetching time of > 30 minutes was reported by 25% of cases versus 15% of controls and was significantly associated with MSD where rainwater was not used in the last 2 weeks (odds ratio = 1.97, 95% confidence interval = 1.56-2.49). These data support the United Nations definition of access to an improved water source being within 30 minutes total round-trip travel time. PMID:26928833

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

    PubMed

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

    2014-10-01

    We describe the "tumor-based case-control" study as a type of epidemiologic study used to evaluate associations between infectious agents and cancer. These studies assess exposure using diseased tissues from affected individuals (i.e., evaluating tumor tissue for cancer cases), but they must utilize nondiseased tissues to assess control subjects, who do not have the disease of interest. This approach can lead to exposure misclassification in two ways. First, concerning the "when" of exposure assessment, retrospective assessment of tissues may not accurately measure exposure at the key earlier time point (i.e., during the etiologic window). Second, concerning the "where" of exposure assessment, use of different tissues in cases and controls can have different accuracy for detecting the exposure (i.e., differential exposure misclassification). We present an example concerning the association of human papillomavirus with various cancers, where tumor-based case-control studies likely overestimate risk associated with infection. In another example, we illustrate how tumor-based case-control studies of Helicobacter pylori and gastric cancer underestimate risk. Tumor-based case-control studies can demonstrate infection within tumor cells, providing qualitative information about disease etiology. However, measures of association calculated in tumor-based case-control studies are prone to over- or underestimating the relationship between infections and subsequent cancer risk. PMID:25063520

  16. Analgesics use and ESRD in younger age: a case-control study

    PubMed Central

    van der Woude, Fokke J; Heinemann, Lothar AJ; Graf, Helmut; Lewis, Michael; Moehner, Sabine; Assmann, Anita; Kühl-Habich, Doerthe

    2007-01-01

    Background An ad hoc peer-review committee was jointly appointed by Drug Authorities and Industry in Germany, Austria and Switzerland in 1999/2000 to review the evidence for a causal relation between phenacetin-free analgesics and nephropathy. The committee found the evidence as inconclusive and requested a new case-control study of adequate design. Methods We performed a population-based case-control study with incident cases of end-stage renal disease (ESRD) under the age of 50 years and four age and sex-matched neighborhood controls in 170 dialysis centers (153 in Germany, and 17 in Austria) from January 1, 2001 to December 31, 2004. Data on lifetime medical history, risk factors, treatment, job exposure and intake of analgesics were obtained in a standardized face-to-face interview using memory aids to enhance accuracy. Study design, study performance, analysis plan, and study report were approved by an independent international advisory committee and by the Drug Authorities involved. Unconditional logistic regression analyses were performed. Results The analysis included 907 cases and 3,622 controls who had never used phenacetin-containing analgesics in their lifetime. The use of high cumulative lifetime dose (3rd tertile) of analgesics in the period up to five years before dialysis was not associated with later ESRD. Adjusted odds ratios with 95% confidence intervals were 0.8 (0.7 – 1.0) and 1.0 (0.8 – 1.3) for ever- compared with no or low use and high use compared with low use, respectively. The same results were found for all analgesics and for mono-, and combination preparations with and without caffeine. No increased risk was shown in analyses stratifying for dose and duration. Dose-response analyses showed that analgesic use was not associated with an increased risk for ESRD up to 3.5 kg cumulative lifetime dose (98 % of the cases with ESRD). While the large subgroup of users with a lifetime dose up to 0.5 kg (278 cases and 1365 controls) showed a

  17. Ongoing monitoring of data clustering in multicenter studies

    PubMed Central

    2012-01-01

    Background Multicenter study designs have several advantages, but the possibility of non-random measurement error resulting from procedural differences between the centers is a special concern. While it is possible to address and correct for some measurement error through statistical analysis, proactive data monitoring is essential to ensure high-quality data collection. Methods In this article, we describe quality assurance efforts aimed at reducing the effect of measurement error in a recent follow-up of a large cluster-randomized controlled trial through periodic evaluation of intraclass correlation coefficients (ICCs) for continuous measurements. An ICC of 0 indicates the variance in the data is not due to variation between the centers, and thus the data are not clustered by center. Results Through our review of early data downloads, we identified several outcomes (including sitting height, waist circumference, and systolic blood pressure) with higher than expected ICC values. Further investigation revealed variations in the procedures used by pediatricians to measure these outcomes. We addressed these procedural inconsistencies through written clarification of the protocol and refresher training workshops with the pediatricians. Further data monitoring at subsequent downloads showed that these efforts had a beneficial effect on data quality (sitting height ICC decreased from 0.92 to 0.03, waist circumference from 0.10 to 0.07, and systolic blood pressure from 0.16 to 0.12). Conclusions We describe a simple but formal mechanism for identifying ongoing problems during data collection. The calculation of the ICC can easily be programmed and the mechanism has wide applicability, not just to cluster randomized controlled trials but to any study with multiple centers or with multiple observers. PMID:22413923

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

    PubMed

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

    2014-01-01

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

  19. The Multi-center Airborne Coherent Atmospheric Wind Sensor.

    NASA Astrophysics Data System (ADS)

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

    1998-04-01

    In 1992 the atmospheric lidar remote sensing groups of the National Aeronautics and Space Administration Marshall Space Flight Center, the National Oceanic and Atmospheric Administration/Environmental Technology Laboratory (NOAA/ETL), and the Jet Propulsion Laboratory began a joint collaboration to develop an airborne high-energy Doppler laser radar (lidar) system for atmospheric research and satellite validation and simulation studies. The result is the Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS), which has the capability to remotely sense the distribution of wind and absolute aerosol backscatter in three-dimensional volumes in the troposphere and lower stratosphere.A factor critical to the programmatic feasibility and technical success of this collaboration has been the utilization of existing components and expertise that were developed for previous atmospheric research by the respective institutions. For example, the laser transmitter is that of the mobile ground-based Doppler lidar system developed and used in atmospheric research for more than a decade at NOAA/ETL.The motivation for MACAWS is threefold: 1) to obtain fundamental measurements of subsynoptic-scale processes and features to improve subgrid-scale parameterizations in large-scale models, 2) to obtain datasets in order to improve the understanding of and predictive capabilities for meteorological systems on subsynoptic scales, and 3) to validate (simulate) the performance of existing (planned) satellite-borne sensors.Initial flight tests were made in September 1995; subsequent flights were made in June 1996 following system improvements. This paper describes the MACAWS instrument, principles of operation, examples of measurements over the eastern Pacific Ocean and western United States, and future applications.

  20. Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS)

    NASA Astrophysics Data System (ADS)

    Rhothermel, Jeffry; Jones, W. D.; Dunkin, J. A.; McCaul, E. W., Jr.

    1993-01-01

    This effort involves development of a calibrated, pulsed coherent CO2 Doppler lidar, followed by a carefully-planned and -executed program of multi-dimensional wind velocity and aerosol backscatter measurements from the NASA DC-8 research aircraft. The lidar, designated as the Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS), will be applicable to two research areas. First, MACAWS will enable specialized measurements of atmospheric dynamical processes in the planetary boundary layer and free troposphere in geographic locations and over scales of motion not routinely or easily accessible to conventional sensors. The proposed observations will contribute fundamentally to a greater understanding of the role of the mesoscale, helping to improve predictive capabilities for mesoscale phenomena and to provide insights into improving model parameterizations of sub-grid scale processes within large-scale circulation models. As such, it has the potential to contribute uniquely to major, multi-institutional field programs planned for the mid 1990's. Second, MACAWS measurements can be used to reduce the degree of uncertainty in performance assessments and algorithm development for NASA's prospective Laser Atmospheric Wind Sounder (LAWS), which has no space-based instrument heritage. Ground-based lidar measurements alone are insufficient to address all of the key issues. To minimize costs, MACAWS is being developed cooperatively by the lidar remote sensing groups of the Jet Propulsion Laboratory, NOAA Wave Propagation Laboratory, and MSFC using existing lidar hardware and manpower resources. Several lidar components have already been exercised in previous airborne lidar programs (for example, MSFC Airborne Doppler Lidar System (ADLS) used in 1981,4 Severe Storms Wind Measurement Program; JPL Airborne Backscatter Lidar Experiment (ABLE) used in 1989,90 Global Backscatter Experiment Survey Missions). MSFC has been given responsibility for directing the overall

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

    PubMed Central

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

    2014-01-01

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

  2. Multicenter assessment of burn team injury prevention knowledge.

    PubMed

    Klas, Karla S; Smith, Sue Jane; Matherly, Annette F; Dillard, B Daniel; Grant, Ernest J; Cusick-Jost, Janet

    2015-01-01

    Engaging burn professionals to utilize "teachable moments" and provide accurate fire safety and burn prevention (FSBP) education is essential in reducing injury incidence. Minimal data is available regarding burn clinicians' evidence-based FSBP knowledge. A committee of prevention professionals developed, pilot-tested, and distributed a 52-question online survey assessing six major categories: demographical information (n = 7); FSBP knowledge (n = 24); home FSBP practices (n = 6); burn center FSBP education (n = 7); self-assessed competence and confidence in providing FSBP education (n = 2); and improving ABA reach (n = 6). Responses with <50% completion of FSBP knowledge section were excluded. Total group's (TG) mean FSBP score of 61.5% was used to define and compare underperformers (UP). After excluding 36 incomplete responses, test scores ranged: TG (n = 427) 21-88% and UP (n = 183) 21-58%. Ten FSBP knowledge questions covering seven topics were incorrectly answered by >50% of TG. ANOVA showed self-reported competence and confidence in providing FSBP education were not good predictors of FSBP scores, but staff with <2 years experience scored lower. Over 90% of TG wants FSBP fact sheets for patient education. Burn professionals have a responsibility to educate patients, families, and communities on FSBP. Team members report competence and confidence in their ability to provide FSBP education. However, this multicenter survey demonstrates the need for professional training on best practices in injury prevention, specifically targeting knowledge gaps on: smoke alarms, fire-safe cigarettes, children's sleepwear, burn/fire epidemiology, fireworks, bathing/scald injuries, and residential sprinklers. Based on these findings, FSBP educational materials will be created. PMID:25094010

  3. Neurophysiology versus clinical genetics in Rett syndrome: A multicenter study.

    PubMed

    Halbach, Nicky; Smeets, Eric E; Julu, Peter; Witt-Engerström, Ingegerd; Pini, Giorgio; Bigoni, Stefania; Hansen, Stig; Apartopoulos, Flora; Delamont, Robert; van Roozendaal, Kees; Scusa, Maria F; Borelli, Paolo; Candel, Math; Curfs, Leopold

    2016-09-01

    Many studies have attempted to establish the genotype-phenotype correlation in Rett syndrome (RTT). Cardiorespiratory measurements provide robust objective data, to correlate with each of the different clinical phenotypes. It has important implications for the management and treatment of this syndrome. The aim of this study was to correlate the genotype with the quantitative cardiorespiratory data obtained by neurophysiological measurement combined with a clinical severity score. This international multicenter study was conducted in four European countries from 1999 to 2012. The study cohort consisted of a group of 132 well-defined RTT females aged between 2 and 43 years with extended clinical, molecular, and neurophysiological assessments. Diagnosis of RTT was based on the consensus criteria for RTT and molecular confirmation. Genotype-phenotype analyses of clinical features and cardiorespiratory data were performed after grouping mutations by the same type and localization or having the same putative biological effect on the MeCP2 protein, and subsequently on eight single recurrent mutations. A less severe phenotype was seen in females with CTS, p.R133C, and p.R294X mutations. Autonomic disturbances were present in all females, and not restricted to nor influenced by one specific group or any single recurrent mutation. The objective information from non-invasive neurophysiological evaluation of the disturbed central autonomic control is of great importance in helping to organize the lifelong care for females with RTT. Further research is needed to provide insights into the pathogenesis of autonomic dysfunction, and to develop evidence-based management in RTT. © 2016 Wiley Periodicals, Inc. PMID:27354166

  4. Analytically reduced form of multicenter integrals from Gaussian transforms. [in atomic and molecular physics

    NASA Technical Reports Server (NTRS)

    Straton, Jack C.

    1989-01-01

    The four-dimensional Fourier-Feynman transformations previously used in analytically reducing the general class of integrals containing multicenter products of 1s hydrogenic orbitals, Coulomb or Yukawa potentials, and plane waves, are replaced by the one-dimensional Gaussian transformation. This reduces the previously required double-diagonalization of the quadratic form of the multicenter integrals to only one diagonalization, yielding a simpler reduced form of the integral. The present work also extends the result to include all s states and pairs of states with l not equal to zero summed over the m quantum number.

  5. MGMT Leu84Phe Polymorphism Contributes to Cancer Susceptibility: Evidence from 44 Case-Control Studies

    PubMed Central

    Yu, Cuicui; Sun, Yan; Jia, Chuanliang; Zhang, Lijing; Salahuddin, Taufiq; Li, Xiaodong; Lang, Juntian; Song, Xicheng

    2013-01-01

    Background O6-methylguanine-DNA methyltransferase is one of the few proteins to directly remove alkylating agents in the human DNA direct reversal repair pathway. A large number of case-control studies have been conducted to explore the association between MGMT Leu84Phe polymorphism and cancer risk. However, the results were not consistent. Methods We carried out a meta-analysis of 44 case-control studies to clarify the association between the Leu84Phe polymorphism and cancer risk. Results Overall, significant association of the T allele with cancer susceptibility was verified with meta-analysis under a recessive genetic model (P<0.001, OR=1.30, 95%CI 1.24-1.50) and TT versus CC comparison (P=0.001, OR=1.29, 95% CI 1.12-1.50). In subgroup analysis, a significant increased risk was found for lung cancer (TT versus CC, P=0.027, OR=1.67, 95% CI 1.06-2.63; recessive genetic model, P=0.32, OR=1.64, 95% CI 1.04-2.58), whereas risk of colorectal cancer was significantly low under a dominant genetic model (P=0.019, OR=0.84, 95% CI 0.72-0.97). Additionally, a significant association between TT genetic model and total cancer risk was found in the Caucasian population (TT versus CC, P=0.014, OR=1.29, 95% CI 1.05-1.59; recessive genetic model, P=0.009, OR=1.31, 95% CI 1.07-1.61), but not in the Asian population. An increased risk for lung cancer was also verified in the Caucasian population (TT versus CC, P=0.035, OR=1.62, 95% CI 1.04-2.53; recessive genetic model, P=0.048, OR=1.57, 95% CI 1.01-2.45). Conclusions These results suggest that MGMT Leu84Phe polymorphism might contribute to the susceptibility of certain cancers. PMID:24086516

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

    PubMed

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

    2016-02-01

    Bovine viral diarrhoea virus (BVDV) causes one of the most important diseases of cattle in terms of economic costs and welfare. The aims were to estimate herd prevalence and to investigate the factors associated with antibodies in bulk tank milk (BTM) in dairy herds through a matched case-control study. To estimate herd prevalence, BTM samples were randomly selected (n = 314) from a population (N = 1604). The true prevalence of BVDV was 24.3% (CI 95% = 20.1-29.3%). For the case-control study, BVDV antibody-positive herds (high antibody titres) were classified as cases (n = 21) and matched (n = 63) by milk production with herds presenting low antibody titres (ratio of 1 : 3). Three multivariable models were built: 1) full model, holding all 21 variables, and two models divided according to empirical knowledge and similarity among variables; 2) animal factor model; and 3) biosecurity model. The full model (model 1) identified: age as a culling criteria (OR = 0.10; CI 95% = 0.02-0.39; P < 0.01); farms that provided milk to other industries previously (OR = 4.13; CI 95% = 1.17-14.49; P = 0.02); and isolation paddocks for ill animals (OR = 0.14; CI 95% = 0.01-0.26; P = 0.02). The biosecurity model revealed a significant association with the use of natural mating (OR = 9.03; CI 95% = 2.14-38.03; P < 0.01); isolation paddocks for ill animals (OR = 0.06; CI 95% = 0.05-0.83; P = 0.03); years providing milk for the same industry (OR = 0.94; CI 95% = 0.91-0.97; P = 0.02); and direct contact over fences among cattle of neighbouring farms (OR = 5.78; CI 95% = 1.41-23.67; P = 0.04). We recommend the application of grouping predictors as a good choice for model building because it could lead to a better understanding of disease-exposure associations. PMID:24661884

  7. A Metagenomics and Case-Control Study To Identify Viruses Associated with Bovine Respiratory Disease

    PubMed Central

    Kondov, Nikola O.; Deng, Xutao; Van Eenennaam, Alison; Neibergs, Holly L.

    2015-01-01

    approach, we characterized the viruses in respiratory secretions from BRD cases and identified known and previously uncharacterized viruses belonging to seven viral families. Using a case-control format with location-matched animals, we compared the rates of viral detection and identified 3 viruses associated with severe BRD signs. Combining a metagenomics and case-control format can provide candidate pathogens associated with complex infectious diseases and inform further studies aimed at reducing their impact. PMID:25740998

  8. Case-control study of sudden infant death syndrome in Lithuania, 1997–2000

    PubMed Central

    Bubnaitienė, Vilija; Kalėdienė, Ramunė; Kėvalas, Rimantas

    2005-01-01

    Background To identify risk factors for sudden infant death syndrome relevant in Lithuania. Methods A nationwide case-control study surveying parents of 35 infants who died from sudden infant death syndrome during the period of 1997–2000 and parents of 145 control infants matched with SIDS infants for date of birth and for region of birth was carried out. Results Deaths incidence was greater in the warm period (60%) vs. cold period (40%). Prone and side sleeping positions both carried no increased risk of sudden infant death syndrome compared with supine because of a rare prone sleeping (4.1% of controls vs. 0% of dead infants) and more prevalent side than supine sleeping (84.8% of controls vs. 94.3% of dead infants) in the controls as well as the cases. Bed sharing for the whole night as a risk factor for sudden infant death syndrome has not been confirmed, either, as bed sharing was common only for the controls (13.8% of controls vs. 0% of dead infants). Routine sleeping environment factors such as heavy wrapping (≥4 togs) of an infant (odds ratio 8.49; 95% confidence interval 2.38 to 30.32), sleeping in a bassinet (4.22; 1.16 to 15.38) and maternal factors such as maternal education ≤12 years (4.48; 1.34 to 14.94), unplanned pregnancy (5.22; 1.49 to 18.18) and ≥2 previous live births (3.90; 1.00 to 15.10) were significantly associated with sudden infant death syndrome on multivariate analysis. Conclusion The results of this first population-based case-control study have shed some light on the epidemiology of the syndrome in Lithuania. Although the mortality of sudden infant death syndrome in Lithuania is not high, it might be lowered moreover by public informing about sudden infant death syndrome and related risk factors. Special attention must be paid to mothers with low education on potentially modifiable risk factors such as routine heavy wrapping of an infant during sleep, routine sleeping in a bassinet and unplanned pregnancy. PMID:16283946

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

    PubMed Central

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

    2012-01-01

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

  10. An overview of the North American residential radon and lung cancer case-control studies.

    PubMed

    Field, R William; Krewski, Daniel; Lubin, Jay H; Zielinski, Jan M; Alavanja, Michael; Catalan, Vanessa S; Klotz, Judith B; Létourneau, Ernest G; Lynch, Charles F; Lyon, Joseph L; Sandler, Dale P; Schoenberg, Janet B; Steck, Daniel J; Stolwijk, Jan A; Weinberg, Clarice; Wilcox, Homer B

    2006-04-01

    Lung cancer has held the distinction as the most common cancer type worldwide since 1985 (Parkin et al., 1993). Recent estimates suggest that lung cancer accounted for 1.2 million deaths worldwide in 2002, which represents 17.6% of the global cancer deaths (Parkin et al., 2005). During 2002, the highest lung cancer rates for men worldwide reportedly occurred in North America and Eastern Europe, whereas the highest rates in females occurred in North America and Northern Europe (Parkin et al., 2005). While tobacco smoking is the leading risk factor for lung cancer, because of the magnitude of lung cancer mortality, even secondary causes of lung cancer present a major public health concern (Field, 2001). Extrapolations from epidemiologic studies of radon-exposed miners project that approximately 18,600 lung cancer deaths per year (range 3000 to 41,000) in the United States alone are attributable to residential radon progeny exposure (National Research Council, 1999). Because of differences between the mines and the home environment, as well as differences (such as breathing rates) between miners and the general public, there was a need to directly evaluate effects of radon in homes. Seven major residential case-control radon studies have been conducted in North America to directly examine the association between prolonged radon progeny (radon) exposure and lung cancer. Six of the studies were performed in the United States including studies in New Jersey, Missouri (two studies), Iowa, and the combined states study (Connecticut, Utah, and southern Idaho). The seventh study was performed in Winnipeg, Manitoba, Canada. The residential case-control studies performed in the United States were previously reviewed elsewhere (Field, 2001). The goal of this review is to provide additional details regarding the methodologies and findings for the individual studies. Radon concentration units presented in this review adhere to the types (pCi/L or Bq/m3) presented in the

  11. 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

  12. 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

  13. Vitamin C Intake and Pancreatic Cancer Risk: A Meta-Analysis of Published Case-Control and Cohort Studies

    PubMed Central

    Hua, Yong-Fei; Wang, Gao-Qing; Jiang, Wei; Huang, Jing; Chen, Guo-Chong; Lu, Cai-De

    2016-01-01

    Background Observational studies inconsistently reported the relationship between vitamin C intake and risk of pancreatic cancer. We conducted a meta-analysis of published case-control and cohort studies to quantify the association. Methods Potentially eligible studies were found on PubMed and EMBASE databases through May 31, 2015. A random-effects model was assigned to compute summary point estimates with corresponding 95% confidence intervals (CIs). Subgroup and meta-regression analyses were also performed to explore sources of heterogeneity. Results Our final analyses included 20 observational studies comprising nearly 5 thousand cases of pancreatic cancer. When comparing the highest with the lowest categories of vitamin C intake, the summary odds ratio/relative risk for case-control studies (14 studies), cohort studies (6 studies) and all studies combined was 0.58 (95% CI: 0.52–0.66), 0.93 (95% CI: 0.78–1.11) and 0.66 (95% CI: 0.58–0.75), respectively. The difference in the findings between case-control and cohort studies was statistically significant (P < .001). Possible publication bias was shown in the meta-analysis of case-control studies. Conclusion There is insufficient evidence to conclude any relationship between vitamin C intake and risk of pancreatic cancer. The strong inverse association observed in case-control studies may be affected by biases (eg, recall and selection biases) that particularly affect case-control studies and/or potential publication bias. Future prospective studies of vitamin C intake and pancreatic cancer are needed. PMID:26859881

  14. Borderline Ovarian Tumors and Diagnostic Dilemma of Intraoperative Diagnosis: Could Preoperative He4 Assay and ROMA Score Assessment Increase the Frozen Section Accuracy? A Multicenter Case-Control Study

    PubMed Central

    Gizzo, Salvatore; Berretta, Roberto; Di Gangi, Stefania; Guido, Maria; Zanni, Giuliano Carlo; Franceschetti, Ilaria; Quaranta, Michela; Plebani, Mario; Nardelli, Giovanni Battista; Patrelli, Tito Silvio

    2014-01-01

    The aim of our study was to assess the value of a preoperative He4-serum-assay and ROMA-score assessment in improving the accuracy of frozen section histology in the diagnosis of borderline ovarian tumors (BOT). 113 women presenting with a unilateral ovarian mass diagnosed as serous/mucinous BOT at frozen-section-histology (FS) and/or confirmed on final pathology were recruited. Pathologists were informed of the results of preoperative clinical/instrumental assessment of all patients. For Group_A patients, additional information regarding He4, CA125, and ROMA score was available (in Group_B only CA125 was known). The comparison between Group A and Group B in terms of FS accuracy, demonstrated a consensual diagnosis in 62.8% versus 58.6% (P: n.s.), underdiagnosis in 25.6% versus 41.4% (P < 0.05), and overdiagnosis in 11.6% versus 0% (P < 0.01). Low FS diagnostic accuracy was associated with menopausal status (OR: 2.13), laparoscopic approach (OR: 2.18), mucinous histotype (OR: 2.23), low grading (OR: 1.30), and FIGO stage I (OR: 2.53). Ultrasound detection of papillae (OR: 0.29), septa (OR: 0.39), atypical vascularization (OR: 0.34), serum He4 assay (OR: 0.39), and ROMA score assessment (OR: 0.44) decreased the probability of underdiagnosis. A combined preoperative assessment through serum markers and ultrasonographic features may potentially reduce the risk of underdiagnosis of BOTs on FS while likely increasing the concomitant incidence of false-positive events. PMID:25431767

  15. Evaluation of sleep disturbances in children with epilepsy: a questionnaire-based case-control study.

    PubMed

    Chan, Bosco; Cheong, Eric Yau Kin; Ng, Sui Fun Grace; Chan, Yick Chun; Lee, Qun Ui; Chan, Kwok Yin

    2011-08-01

    Epilepsy is a chronic neurological disorder accompanied by a wide range of comorbid conditions that can adversely affect the quality of life of children. Sleep disturbances not only predispose children to mood, cognitive, and behavioral impairments, but also have a significant impact on physical health. The aim of this study was to evaluate sleep patterns among Chinese children with epilepsy and healthy subjects in Hong Kong, and examine the relationship between parent-reported sleep problems and specific epilepsy parameters. We conducted a cross-sectional, questionnaire-based, case-control study and included 63 children with epilepsy and 169 healthy children aged between 4 and 12 years. The Children's Sleep Habits Questionnaire (CSHQ) was used as an assessment tool. Our results indicated that children with epilepsy have similar sleep patterns but greater sleep disturbances compared with healthy subjects. Sleep problems should not be overlooked, and a comprehensive review of the sleep habits of this group of patients should be conducted. PMID:21704566

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

    PubMed

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

    2016-04-01

    This study aimed to comprehensively evaluate factors that influence the likelihood of syphilis infection from risk-taking behaviours and medical conditions. A retrospective case-control study was conducted by enrolling 664 syphilis inpatients (excluding 11 congenital syphilis patients) and 800 sex- and age-matched controls. Medical histories, clinical data and patient interview data were collected and subjected to logistic regression analyses. The prevalence of syphilis in the study population was 3·9% (675/17,304). By univariate analysis, syphilis infection was associated with migration between cities, marital status, smoking, reproductive history, hypertension, elevated blood urea nitrogen (BUN) and infection with hepatitis B virus (HBV) (P < 0·05). A high rate of syphilis-HBV co-infection was observed in HIV-negative patients and further research revealed an association between syphilis and specific HBV serological reactivity. Syphilis was also associated with the frequency, duration and status of tobacco use. Multivariate analysis indicated that syphilis infection was independently associated with migration between cities [adjusted odds ratio (aOR) 1·368, 95% confidence interval (CI) 1·048-1·785], current smoking (aOR 1·607, 95% CI 1·177-2·195), elevated BUN (aOR 1·782, 95% CI 1·188-2·673) and some serological patterns of HBV infection. To prevent the spread of infectious diseases, inpatients and blood donors should be tested for HIV, syphilis, HBV and HCV simultaneously. PMID:26467944

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

    PubMed Central

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

    2016-01-01

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

  18. Risk assessment of feline tooth resorption: a Portuguese clinical case control study.

    PubMed

    Mestrinho, Lisa A; Runhau, Jens; Bragança, Mauro; Niza, Maria M R E

    2013-01-01

    Tooth resorption (TR) is one of the most common dental diseases in cats. Determination of risk factors has not yet been fully assessed and, to the best knowledge of the authors, this disease has never been studied in Portuguese cats. The objective of this case-control study was to determine type and distribution of TR lesions, evaluate risk factors, and establish relationships between variables in this disease. The study included data from 71 cats admitted for general anesthesia for various reasons. The cats were randomly selected. The inclusion criteria were availability of clinical history and owner permission. Cats with known oral disease were not excluded from the study. All cats received ultrasonic scaling and polishing of the teeth, a thorough oral examination, and full-mouth radiographs. A strong statistical relation was found between age and TR. The age group of 10 to 15-years showed an increased risk of 6.56 times for TR occurrence compared with the group 0 to 4-years of age. Presence of gingivitis in all index levels was related to an increased risk for TR. No relation was found between age or gingivitis index and lesion type. Mandibular third premolar and molar teeth were most commonly affected by TR, especially for type 1 lesions. Canine teeth were statistically more likely to have type 2 lesions. The trend for the canine teeth to be more affected with type 2 lesions needs further verification. PMID:24006716

  19. Statin use and the risk of colorectal cancer: A population-based case-control study

    PubMed Central

    Cheng, Meng-Hsuan; Chiu, Hui-Fen; Ho, Shu-Chen; Tsai, Shang-Shyue; Wu, Trong-Neng; Yang, Chun-Yuh

    2011-01-01

    AIM: To investigate whether the use of statins is associated with colorectal cancer risk. METHODS: We conducted a population-based case-control study in Taiwan. Data were retrospectively collected from the Taiwan National Health Insurance Research Database. Cases consisted of all patients who were aged 50 years and older and had a first-time diagnosis of colorectal cancer between the period 2005 and 2008. The controls were matched to cases by age, sex, and index date. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multiple logistic regression. RESULTS: We examined 1156 colorectal cancer cases and 4624 controls. The unadjusted ORs for any statin prescription was 1.10 (95% CI = 0.94-1.30) and the adjusted OR was 1.09 (95% CI = 0.91-1.30). When statin use was categorized by cumulative dose, the adjusted ORs were 0.99 (95% CI = 0.78-1.27) for the group with cumulative statin use below 105 defined daily doses (DDDs); 1.07 (95% CI = 0.78-1.49) for the group with cumulative statin use between 106 and 298.66 DDDs; and 1.30 (95% CI = 0.96-1.75) for the group with cumulative statin use of 298.66 DDDs or more compared with nonusers. CONCLUSION: This study does not provide support for a protective effect of statins against colorectal cancer. PMID:22215945

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

    PubMed Central

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

    2016-01-01

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

  1. Melanoma and occupation: results of a case-control study in The Netherlands.

    PubMed

    Nelemans, P J; Scholte, R; Groenendal, H; Kiemeney, L A; Rampen, F H; Ruiter, D J; Verbeek, A L

    1993-07-01

    Several studies have reported excesses of risk of melanoma in specific industries. Data from a case-control study in The Netherlands, including 140 cases with a cutaneous melanoma and 181 controls with other types of malignancy, were used to evaluate whether the reported associations with these specific industries could be reproduced. Adjustment for characteristics of pigmentation and exposure to sunlight was made. Increased risks of cutaneous melanoma were found for subjects who had ever worked in the electronics industry (odds ratio (OR) = 2.03, 95% confidence interval (95% CI) 0.63-6.62), in the metal industry (OR = 2.61, 95% CI 0.96-7.10), and in the transport and communication branch (OR = 1.92, 95% CI 0.84-4.35). These ORs were adjusted for age, sex, education, hair colour, tendency to burn, freckling, and exposure to sunlight. No increased risks were seen for workers in the chemical industry, the textile industry, and among health care workers. Analyses according to duration and latency of exposure did not give consistent results, but existing patterns may be obscured by the imprecision of the estimates. PMID:8343426

  2. A Shrinkage Method for Testing the Hardy-Weinberg Equilibrium in Case-Control Studies

    PubMed Central

    Zang, Yong; Yuan, Ying

    2014-01-01

    Testing for the Hardy-Weinberg equilibrium (HWE) is often used as an initial step for checking the quality of genotyping. When testing the HWE for case-control data, the impact of a potential genetic association between the marker and the disease must be controlled for otherwise the results may be biased. Li and Li (2008) proposed a likelihood ratio test (LRT) that accounts for this potential genetic association and it is more powerful than the commonly used control-only χ2 test. However, the LRT is not efficient when the marker is independent of the disease, and also requires numerical optimization to calculate the test statistic. In this article, we propose a novel shrinkage test for assessing the HWE. The proposed shrinkage test yields higher statistical power than the LRT when the marker is independent of or weakly associated with the disease, and converges to the LRT when the marker is strongly associated with the disease. In addition, the proposed shrinkage test has a closed form and can be easily used to test the HWE for large datasets that result from genome-wide association studies. We compare the performance of the shrinkage test with existing methods using simulation studies, and apply the shrinkage test to a genome-wide association dataset for Alzheimer’s disease. PMID:23934751

  3. Urinary strontium and the risk of breast cancer: a case-control study in Guangzhou, China.

    PubMed

    Chen, Li-Juan; Tang, Lu-Ying; He, Jian-Rong; Su, Yi; Cen, Yu-Ling; Yu, Dan-Dan; Wu, Bang-Hua; Lin, Ying; Chen, Wei-Qing; Song, Er-Wei; Ren, Ze-Fang

    2012-01-01

    Strontium has been widely used in industries like electronic and pharmacy. It has a carcinogenic potential, however, and no study has been conducted to evaluate its effects on cancer risk. The aim of this study was to explore the possible association between strontium and breast cancer risk in a case-control study including 240 incident invasive breast cancer patients and 246 age-matched controls. We measured the urinary concentrations of strontium by inductively coupled plasma mass spectrometry, and conducted face-to-face interviews to obtain information on potential breast cancer risk factors. Multivariable analysis was used to estimate the association. Creatinine-adjusted levels [median (25th, 75th) μg/g] of strontium were 155.59 (99.05, 230.70) in the breast cancer patients and 119.62 (81.97, 163.76) in the controls. Women in the highest tertile of strontium showed 124% increased risk of breast cancer, when compared with those in the lowest tertile after adjustment for the potential risk factors [OR (95% CI): 2.24 (1.42-3.81)]. This association was particularly strong for HER2 positive breast cancer [OR (95% CI): 10.92 (3.53-33.77)], and only occurred among premenopausal women. These results suggest a potential role of strontium in the development of breast cancer and urge further studies on the environmental contamination and the physiological and pathological mechanisms of strontium. PMID:22172139

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

    PubMed Central

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

    2012-01-01

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

  5. Case-control study of prenatal ultrasonography exposure in children with delayed speech.

    PubMed Central

    Campbell, J D; Elford, R W; Brant, R F

    1993-01-01

    OBJECTIVE: To determine whether there is an association between prenatal ultrasound exposure and delayed speech in children. DESIGN: Case-control study. SETTING: Network of community physicians affiliated with the Primary Care Research Unit, University of Calgary. SUBJECTS: Thirty-four practitioners identified 72 children aged 24 to 100 months who had undergone a formal speech-language evaluation and were found to have delayed speech of unknown cause by a speech-language pathologist. For each case subject the practitioners found two control subjects matched for sex, date of birth, sibling birth order and associated health problems. MAIN OUTCOME MEASURES: Rates of prenatal ultrasound exposure and delayed speech. RESULTS: The children with delayed speech had a higher rate of ultrasound exposure than the control subjects. The findings suggest that a child with delayed speech is about twice as likely as a child without delayed speech to have been exposed to prenatal ultrasound waves (odds ratio 2.8, 95% confidence limit 1.5 to 5.3; p = 0.001). CONCLUSION: An association between prenatal ultrasonography exposure and delayed speech was found. If there is no obvious clinical indication for diagnostic in-utero ultrasonography, physicians might be wise to caution their patients about the vulnerability of the fetus to noxious agents. PMID:8221427

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

    PubMed

    Lu, Haixia; Zhu, Ce; Li, Fei; Xu, Wei; Tao, Danying; Feng, Xiping

    2016-01-01

    Little is known about herpesvirus and putative periodontopathic bacteria in maternal chronic periodontitis. The present case-control study aimed to explore the potential relationship between putative periodontopathic bacteria and herpesviruses in maternal chronic periodontitis.Saliva samples were collected from 36 pregnant women with chronic periodontitis (cases) and 36 pregnant women with healthy periodontal status (controls). Six putative periodontopathic bacteria (Porphyromonas gingivalis [Pg], Aggregatibacer actinomycetemcomitans [Aa], Fusobacterium nucleatum [Fn], Prevotella intermedia [Pi], Tannerella forsythia [Tf], and Treponema denticola [Td]) and three herpesviruses (Epstein-Barr virus [EBV], human cytomegalovirus [HCMV], and herpes simplex virus [HSV]) were detected. Socio-demographic data and oral health related behaviors, and salivary estradiol and progesterone levels were also collected. The results showed no significant differences in socio-demographic background, oral health related behaviors, and salivary estradiol and progesterone levels between the two groups (all P > 0.05). The detection rates of included periodontopathic microorganisms were not significantly different between the two groups (all P > 0.05), but the coinfection rate of EBV and Pg was significantly higher in the case group than in the control group (P = 0.028). EBV and Pg coinfection may promote the development of chronic periodontitis among pregnant women. PMID:27301874

  7. Antidepressants and Gastric Cancer: A Nationwide Population-Based Nested Case-Control Study

    PubMed Central

    Lin, Chiao-Fan; Chan, Hsiang-Lin; Liang, Hsin-Yi; Lee, Yena; McIntyre, Roger S.; Chen, Vincent Chin-Hung

    2015-01-01

    Background To our knowledge, no epidemiological study has reported on whether an association between antidepressant exposure and gastric cancer exists. Herein, we aim to investigate the possible association between antidepressant exposure and gastric cancer incidence. Methods Using a nested case-control design, we identified 26289 cases with gastric cancer and 127984 controls from Taiwan’s National Health Insurance Research Database (NHIRD). The data were analyzed using a conditional logistic regression model adjusting for possible confounding variables. Results We found antidepressant use did not increase the risk of gastric cancer. The lack of an association between antidepressant prescription and elevated gastric cancer incidence was apparent for across selective serotonin-reuptake inhibitors (SSRIs), tricyclic agents (TCAs), serotonin-norepinephrine reuptake inhibitors (SNRIs), reversible inhibitors of monoamine oxidase A (RIMA), trazodone, mirtazapine and bupropion. There were slightly decreased gastric cancer risks of SSRIs use (≧28 DDD group, adjusted OR = 0.87; 95% CI = 0.78–0.96). Sensitive analysis showed SSRIs, TCAs, and SNRIs did not increase gastric cancer risks significantly even in the group with peptic ulcer history. Conclusions An association between antidepressant exposure and gastric cancer was not apparent in this analysis. PMID:26606417

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

    PubMed

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

    2005-07-01

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

  9. Chronic beryllium disease and beryllium sensitization at Rocky Flats: a case-control study.

    PubMed

    Viet, S M; Torma-Krajewski, J; Rogers, J

    2000-01-01

    A case-control study was conducted to evaluate the risk of chronic beryllium disease (CBD) and beryllium sensitization (SENS) associated with various levels of historical beryllium exposure at the Rocky Flats nuclear weapons facility. Fifty CBD and 74 SENS cases were matched to controls of the same age group, race, gender, and smoking status. A job exposure matrix was developed from job history data and fixed airhead (FAH) exposure data available from 1960 to 1988. Job titles and building areas were assigned factors based on exposure relative to a machinist in the Building 444 Beryllium Shop. Concurrence on these factors was obtained from past and present Rocky Flats industrial hygienists. Using the matrix, long-term mean and cumulative exposures were estimated for each subject. Both exposure estimates (p < 0.0001) and years of employment (p = 0.010) were found to be significantly higher for CBD cases as compared with their controls, but not so for the SENS cases as compared with their controls. Logistic regression analyses showed statistically significant relationships between both cumulative and mean exposure and CBD, but not for SENS. These findings suggest that reduced worker exposures might lower the future incidence of CBD, but may not necessarily lower the incidence of SENS. PMID:10782196

  10. Childhood Leukemia and 50 Hz Magnetic Fields: Findings from the Italian SETIL Case-Control Study

    PubMed Central

    Salvan, Alberto; Ranucci, Alessandra; Lagorio, Susanna; Magnani, Corrado

    2015-01-01

    We report on an Italian case-control study on childhood leukemia and exposure to extremely low frequency magnetic fields (ELF-MF). Eligible for inclusion were 745 leukemia cases, aged 0–10 years at diagnosis in 1998–2001, and 1475 sex- and age-matched population controls. Parents of 683 cases and 1044 controls (92% vs. 71%) were interviewed. ELF-MF measurements (24–48 h), in the child’s bedroom of the dwelling inhabited one year before diagnosis, were available for 412 cases and 587 controls included in the main conditional regression analyses. The magnetic field induction was 0.04 μT on average (geometric mean), with 0.6% of cases and 1.6% of controls exposed to >0.3 μT. The impact of changes in the statistical model, exposure metric, and data-set restriction criteria was explored via sensitivity analyses. No exposure-disease association was observed in analyses based on continuous exposure, while analyses based on categorical variables were characterized by incoherent exposure-outcome relationships. In conclusion, our results may be affected by several sources of bias and they are noninformative at exposure levels >0.3 μT. Nonetheless, the study may contribute to future meta- or pooled analyses. Furthermore, exposure levels among population controls are useful to estimate attributable risk. PMID:25689995