scholarly journals O6E.6 Occupational exposures and ALS: international collaborations and new ways to identify risk factors

2019 ◽  
Vol 76 (Suppl 1) ◽  
pp. A61.1-A61
Author(s):  
Susan Peters ◽  
Leonard van den Berg ◽  
Jan Veldink ◽  
Roel Vermeulen
Keyword(s):  
Risk Factors ◽  
Case Control Study ◽  
Disease Onset ◽  
Occupational Exposures ◽  
Case Control ◽  
Incidence Density ◽  
Recall Bias ◽  
Case Control Studies ◽  
Incident Cases ◽  
Control Study

BackgroundAssociations between occupational exposures and amyotrophic lateral sclerosis (ALS) have been suggested, but results are inconsistent. Case-control studies are best suited for inclusion of clinically confirmed incident cases, but prone to recall bias. Cohort studies are free from recall bias and may have pre-symptomatic blood stored, to inform about exposures (e.g. lead) well before disease onset.MethodsAn ongoing nation-wide ALS case-control study has been conducted in the Netherlands since 2006 (currently over 3000 cases and 4500 controls) to study risk factors and possible gene-environment interactions. Part of this study has been pooled with case-control studies from Ireland and Italy (Euro-MOTOR), where the same questionnaire was administered.ResultsWithin the Euro-MOTOR study, ∼1300 cases and ∼2600 controls had full job histories available. Occupational exposures to a range of agents were assessed using job-exposure matrices. Analyses were adjusted for age, sex, centre, education, smoking and alcohol. We found significant associations between ALS and exposure to silica (OR 1.73, 95% CI 1.28–2.33), extremely low-frequency magnetic fields (OR 1.16, 95% CI 1.01–1.33) and electric shocks (OR 1.23, 95% CI 1.05–1.43), independent of the other occupational exposures studied.Future perspectivesA nested ALS case-control study was conducted within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. 219 people who died from ALS have been identified, and pre-symptomatic blood samples from 168 of these cases are available for analyses. Three controls per case were selected by incidence density sampling matched by age at recruitment, sex and study centre. Metal concentrations will be analysed in the erythrocytes. This would be the first prospective study on the association between exposure to metals and ALS.ConclusionEach study design has its strengths and weaknesses, and ALS should be investigated in a range of (occupational) studies to gain better understanding of its aetiology.

scholarly journals Risk factors for progression of juvenile-onset non-radiographic axial spondyloarthritis to juvenile-onset ankylosing spondylitis: a nested case–control study

RMD Open ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. e001867
Author(s):  
Hao-Guang Li ◽  
Dan-Min Wang ◽  
Feng-Cai Shen ◽  
Shu-Xin Huang ◽  
Zhi-Duo Hou ◽  
...  
Keyword(s):  
Risk Factors ◽  
Case Control Study ◽  
Axial Spondyloarthritis ◽  
Disease Onset ◽  
Case Control ◽  
Buttock Pain ◽  
Juvenile Onset ◽  
Factors Associated ◽  
Nested Case Control ◽  
Control Study

ObjectiveTo evaluate the clinical characteristics of juvenile-onset non-radiographic axial spondyloarthritis (nr-axSpA) and to investigate risk factors associated with progression to juvenile-onset ankylosing spondylitis (JoAS).MethodsA nested case–control study was conducted using the retrospectively collected data of 106 patients with juvenile-onset nr-axSpA (age at disease onset, <16 years) in the Clinical characteristic and Outcome in Chinese Axial Spondyloarthritis study cohort. Baseline demographic and clinical characteristics and prognosis were reviewed. Logistic regression analyses were performed to investigate risk factors associated with progression to JoAS.ResultsOverall, 58.5% of patients with juvenile-onset nr-axSpA presented with peripheral symptoms at disease onset. In 82.1% of these patients, axial with peripheral involvement occurred during the disease course. The rate of disease onset at >12 years and disease duration of ≤10 years were significantly higher in those with progression to JoAS than in those without progression to JoAS (83.0% vs 52.8%, p=0.001; 92.5% vs 56.6%, p<0.001, respectively). Multivariable logistic regression analysis revealed that inflammatory back pain (IBP) (OR 13.359 (95% CI 2.549 to 70.013)), buttock pain (OR 10.171 (95% CI 2.197 to 47.085)), enthesitis (OR 7.113 (95% CI 1.670 to 30.305)), elevated baseline C reactive protein (CRP) levels (OR 7.295 (95% CI 1.984 to 26.820)) and sacroiliac joint-MRI (SIJ-MRI) positivity (OR 53.821 (95% CI 9.705 to 298.475)) were significantly associated with progression to JoAS.ConclusionPeripheral involvement was prevalent in juvenile-onset nr-axSpA. IBP, buttock pain, enthesitis, elevated baseline CRP levels and SIJ-MRI positivity in patients with the disease are associated with higher risk of progression to JoAS.

scholarly journals Do Case-Control Studies Always Estimate Odds Ratios?

2020 ◽  
Author(s):  
Jeremy A Labrecque ◽  
Myriam M G Hunink ◽  
M Arfan Ikram ◽  
M Kamran Ikram
Keyword(s):  
Incidence Rate ◽  
Case Control Study ◽  
Case Control ◽  
Small Sample ◽  
Incidence Density ◽  
Odds Ratios ◽  
Case Control Studies ◽  
Rate Ratios ◽  
Study Designs ◽  
Control Study

Abstract Case-control studies are an important part of the epidemiologic literature, yet confusion remains about how to interpret estimates from different case-control study designs. We demonstrate that not all case-control study designs estimate odds ratios. On the contrary, case-control studies in the literature often report odds ratios as their main parameter even when using designs that do not estimate odds ratios. Only studies using specific case-control designs should report odds ratios, whereas the case-cohort and incidence-density sampled case-control studies must report risk ratio and incidence rate ratios, respectively. This also applies to case-control studies conducted in open cohorts, which often estimate incidence rate ratios. We also demonstrate the misinterpretation of case-control study estimates in a small sample of highly cited case-control studies in general epidemiologic and medical journals. We therefore suggest that greater care be taken when considering which parameter is to be reported from a case-control study.

Risk Factors for IgA Nephropathy: A Case-Control Study with Incident Cases in Japan

Nephron ◽  
2001 ◽  
Vol 90 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Kenji Wakai ◽  
Shigeru Nakai ◽  
Seiichi Matsuo ◽  
Takashi Kawamura ◽  
Nigishi Hotta ◽  
...  
Keyword(s):  
Risk Factors ◽  
Iga Nephropathy ◽  
Case Control Study ◽  
Case Control ◽  
Incident Cases ◽  
Control Study

scholarly journals Bias control in the analysis of case–control studies with incidence density sampling

2019 ◽  
Vol 48 (6) ◽  
pp. 1981-1991 ◽  
Author(s):  
Yin Bun Cheung ◽  
Xiangmei Ma ◽  
K F Lam ◽  
Jialiang Li ◽  
Paul Milligan
Keyword(s):  
Logistic Regression ◽  
Reduction Method ◽  
Case Control Study ◽  
Case Control ◽  
Bias Reduction ◽  
Incidence Density ◽  
Haemophilus Influenzae Type ◽  
Case Control Studies ◽  
Residual Time ◽  
Control Study

Abstract Background Previous simulation studies of the case–control study design using incidence density sampling, which required individual matching for time, showed biased estimates of association from conditional logistic regression (CLR) analysis; however, the reason for this is unknown. Separately, in the analysis of case–control studies using the exclusive sampling design, it has been shown that unconditional logistic regression (ULR) with adjustment for an individually matched binary factor can give unbiased estimates. The validity of this analytic approach in incidence density sampling needs evaluation. Methods In extensive simulations using incidence density sampling, we evaluated various analytic methods: CLR with and without a bias-reduction method, ULR with adjustment for time in quintiles (and residual time within quintiles) and ULR with adjustment for matched sets and bias reduction. We re-analysed a case–control study of Haemophilus influenzae type B vaccine using these methods. Results We found that the bias in the CLR analysis from previous studies was due to sparse data bias. It can be controlled by the bias-reduction method for CLR or by increasing the number of cases and/or controls. ULR with adjustment for time in quintiles usually gave results highly comparable to CLR, despite breaking the matches. Further adjustment for residual time trends was needed in the case of time-varying effects. ULR with adjustment for matched sets tended to perform poorly despite bias reduction. Conclusions Studies using incidence density sampling may be analysed by either ULR with adjustment for time or CLR, possibly with bias reduction.

scholarly journals A case control study in BMC Sagar to identify the risk factors for heart failure in patients with recently diagnosed myocardial infarction

2017 ◽  
Vol 4 (5) ◽  
pp. 1222
Author(s):  
Ramesh Pandey ◽  
Shikha Pandey
Keyword(s):  
Risk Factors ◽  
Myocardial Infarction ◽  
Heart Failure ◽  
Case Control Study ◽  
Conditional Logistic Regression ◽  
Case Control ◽  
Madhya Pradesh ◽  
Incidence Density ◽  
Potential Risk Factors ◽  
Control Study

Background: This study was conducted to identify the risk factors for heart failure (HF) in recently diagnosed myocardial infarction (MI) patients in Bundelkhand region of Madhya Pradesh, India.Methods: In this hospital-based, case-control study, the participants were all new myocardial infarction patients hospitalized from April 2016 to March 2017 in Bundelkhand Medical College (BMC) and associated hospital Sagar, Madhya Pradesh. There were 1,691 new cases with heart failure and 6,764 patients without heart failure as controls. Controls were selected randomly as per incidence density sampling. Odds ratios (ORs) with a 95% confidence interval (CI) was calculated to identify potential risk factors, using conditional logistic regression models.Results: The mortality rate was 18.2% in the cases and (12.1%) in the controls (p<0.05). Important risk factors for heart failure were: stroke (OR, 2.00; 95% CI, 1.39 to 2.89), and right bundle branch block (RBBB) (OR, 2.86; 95% CI, 1.95 to 4.19). The factors significantly associated with heart failure Diabetes, hypertension, atrial fibrillation, ventricular tachycardia, and age. Incidence (p<0.05). Significant factor in women was diabetes (OR, 1.41; 95% CI, 1.05 to 1.88) while in men age, hypertension, and RBBB are important.Conclusions: This study might help to identify and monitor the predictive risk factors for heart failure in myocardial infarction patients. The type of risk factors was different in men and women.  

scholarly journals Risk Factors for Mortality Among Patients Diagnosed With Multi-Drug Resistant Tuberculosis In Uganda- A Case-Control Study

2020 ◽  
Author(s):  
Enock Kizito ◽  
Joseph Musaazi ◽  
Kenneth Mutesasira ◽  
Fred Twinomugisha ◽  
Helen Namwanje ◽  
...  
Keyword(s):  
Risk Factors ◽  
Case Control Study ◽  
Conditional Logistic Regression ◽  
Case Control ◽  
World Health ◽  
Incidence Density ◽  
Tb Treatment ◽  
Resistant Tuberculosis ◽  
Mdr Tb ◽  
Control Study

Abstract Background:The World Health Organization (WHO) End TB strategy aims to reduce mortality due to tuberculosis (TB) to less than 5% by 2035. However, mortality due to multidrug-resistant tuberculosis (MDR-TB) is particularly high and stood at 15% globally in 2018. In Uganda, MDR-TB associated mortality was 19% in the same year. We set out to examine the risk factors for mortality among a cohort of patients diagnosed with MDR-TB in Uganda.Methods:We conducted a case-control study nested within the national MDR-TB cohort. We defined cases as patient who died from any cause during the two years following treatment initiation. We selected two controls for each case from patients alive and on MDR-TB treatment at the time that the death occurred (incidence-density sampling) and matched the cases and controls on health facility at which they were receiving care. We performed conditional logistic regression to identify the risk factors for mortality. Results:Data from 198 patients (66 cases and 132 controls) started on TB from January 1 to December 31, 2016, was analyzed for this study. Majority of patients (60.6%) were male and were HIV positive (59.6%). About half (46.0%) were aged 19-34 years. On multiple regression analysis, co-infection with HIV (aOR 1.9, 95% CI [1.1-4.92]p=0.05); non-adherence to TB treatment (aOR 1.92, 95% CI [1.02-4.83] p=0.04); age over 50 years (aOR 3.04, 95% CI [1.13-8.20] p=0.03); and not having any education (aOR 3.61, 95% CI [1.1-10.4] p=0.03) were associated with MDR TB mortality. Conclusion: To improve MDR-TB treatment outcomes, to attention must be paid to provision of social support particularly for older persons on MDR TB treatment. Interventions that support treatment adherence and promote early detection of HIV infection should also be emphasized for all persons diagnosed with TB.

scholarly journals Occupational exposure to organic dusts and risk of developing rheumatoid arthritis: findings from a Swedish population-based case–control study

RMD Open ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. e001049 ◽  
Author(s):  
Anna Ilar ◽  
Per Gustavsson ◽  
Pernilla Wiebert ◽  
Lars Alfredsson
Keyword(s):  
Rheumatoid Arthritis ◽  
Census Data ◽  
Case Control Study ◽  
Occupational Exposures ◽  
Population Based ◽  
Case Control ◽  
Increased Risk ◽  
Flour Dust ◽  
Incident Cases ◽  
Control Study

ObjectivesWe estimated the association between occupational exposures to five different organic dusts: wood, animal, paper, textile and flour dust and the risk of developing rheumatoid arthritis (RA).MethodsThis population-based case–control study analysed 12 582 incident cases and 129 335 controls. Participants were identified from national public authority and quality registers. Census data on occupations were collected 1960–2010 and we estimated the exposure to organic dust with the help of job-exposure matrices. We used logistic regression to assess the OR of seropositive or seronegative RA. Estimates were adjusted for the matching variables (sex, county, age and index year), education and occupational silica exposure.ResultsExposure to animal dust was associated with an increased risk of RA among both men and women. The OR was 1.2 (95% CI=1.1 to 1.4) for seropositive RA and 1.3 (95% CI=1.1 to 1.5) for seronegative RA among ever exposed participants compared with unexposed. The risk increased with duration of exposure for seropositive RA, and participants who had been exposed in five or more censuses had an OR of 1.6 (95% CI=1.1 to 2.2, p for trend=0.003). Exposure to textile dust also generated a significant dose–response relationship for seropositive RA (p for trend=0.014). We detected no association between exposure to wood, paper or flour dust and risk of RA.ConclusionsOverall, exposure to animal dust and textile dust was associated with an increased risk of developing RA. These observations give further support to the notion that airborne exposures are involved in the aetiology of RA.

scholarly journals Risk factors for endometrial carcinoma among postmenopausal women in Sri Lanka: a case control study

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Withanage Iresha udayangani Jayawickcrama ◽  
Chrishantha Abeysena
Keyword(s):  
Risk Factors ◽  
Sri Lanka ◽  
Endometrial Carcinoma ◽  
Postmenopausal Women ◽  
Case Control Study ◽  
Case Control ◽  
Low Level ◽  
Independent Risk Factors ◽  
Incident Cases ◽  
Control Study

Abstract Background Endometrial carcinoma burden is on the rise globally. The objective of this study was to determine the risk factors for endometrial carcinoma among postmenopausal women in Western province in Sri Lanka. Methods A case control study was conducted recruiting 83 incident cases of endometrial carcinoma and 332 unmatched hospital controls from all the secondary and tertiary care hospitals in the province using consecutive sampling technique. A case was defined as a postmenopausal woman who had been residing in the province for at least a period of 1 year, diagnosed to have endometrial carcinoma with histological confirmation within 3 months of the initiation of data collection of the study. Data were collected using validated interviewer administered questionnaire. Risk factor were identified through multiple logistic regression and results were expressed as adjusted odds ratios (AOR) and 95% confidence intervals (CI). Results The independent risk factors of endometrial carcinoma are having family history of any type of cancer among first degree relative (AOR = 12.6; 95% CI:5.14–30.9), generalized obesity (BMI ≥25 kg/m2) (AOR = 11.85; 95% CI:5.12–27.4), never conceived (AOR = 3.84; 95% CI:1.37–10.7), age at menarche ≤11 years (AOR = 4.07; 95% CI:1.16–14.2), age > 55 years (AOR = 4.69; 95% CI:2.16–10.2), monthly family income of ≤20,000 Rupees (AOR = 2.65; 95% CI:1.31–5.39), sub-optimal consumption of deep fried food (AOR = 0.17; 95% CI:0.06–0.46), and low level household activities (AOR = 2.82; 95% CI:1.34–5.92). Conclusions There were eight independent risk factors of endometrial carcinoma specific for Sri Lankan postmenopausal women identified. Some modifiable risk factors such as generalized obesity, sub-optimal dietary practices and low level physical activities need to be addressed at primary prevention level.

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