American journal of epidemiology
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Use of protective equipment is an important sports injury prevention strategy, yet use of protective equipment by high school athletes has seldom been studied. The authors analyzed data from a 3-year (1996-1999), stratified, two-stage cluster sample of athletes from 12 organized sports in 100 North Carolina high schools (n = 19,728 athlete-seasons). Information on each athlete's use of protective equipment and prior injury was collected during the preseason. ⋯ Knee brace use and ankle brace use were associated with increased rates of knee injury (RR = 1.61, 95% CI: 1.08, 2.41) and ankle injury (RR = 1.74, 95% CI: 1.11, 2.72), respectively. This could be due to slippage of the brace during use, increased fatigue due to the energy cost of wearing a brace, or bias in the study. Further investigation into the effects of brace use is warranted.
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Randomized Controlled Trial Clinical Trial
Predictors of lung cancer among asbestos-exposed men in the {beta}-carotene and retinol efficacy trial.
Despite numerous published studies, debate continues regarding the risk of developing lung cancer among men exposed occupationally to asbestos, particularly those without radiographic or functional evidence of asbestosis. The beta-Carotene and Retinol Efficacy Trial (CARET), a study of vitamin supplementation for chemoprevention of lung cancer, has followed 4,060 heavily exposed US men for 9-17 years. Lung cancer incidence for 1989-2002 was analyzed using a stratified proportional hazards model. ⋯ In the large subgroup of men with normal lung parenchyma on chest radiograph at baseline, there was evidence of exposure-related lung cancer risk: Men with more than 40 years' exposure in high-risk trades had a risk approximately fivefold higher than men with 5-10 years, after adjustment for covariates. The effect in these men was independent of study intervention arm, but pleural plaques on the baseline radiograph and abnormal baseline flow rate were strong independent predictors of subsequent lung cancer. Residual confounding by subclinical asbestosis, exposure to unmeasured lung carcinogens, or differences in smoking are unlikely to explain these observations better than a carcinogenic effect of asbestos per se.
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Variations in the validity of hospital discharge diagnoses can complicate the assessment of trends in incidence of acute myocardial infarction (AMI). To clarify trends in the validity of discharge codes, the authors compared event classification based on published Atherosclerosis Risk in Communities (ARIC) Study criteria with the presence or absence of an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) hospital discharge code for AMI (code 410). ⋯ The ethnic difference was related to a greater frequency of hypertensive heart disease and congestive heart failure codes encompassing AMI among Blacks as compared with Whites. The authors found that although the validity of ICD-9-CM code 410 to identify AMI was generally stable from 1987 through 2000, differences between Blacks and Whites and across geographic locations support investment in validation efforts in ongoing surveillance studies.
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Higher intake of fruits, vegetables, and antioxidants may help protect against oxidative damage, thus lowering cancer and cardiovascular disease risk. This Washington County, Maryland, prospective study examined the association of fruit, vegetable, and antioxidant intake with all-cause, cancer, and cardiovascular disease death. CLUE participants who donated a blood sample in 1974 and 1989 and completed a food frequency questionnaire in 1989 (N = 6,151) were included in the analysis. ⋯ No statistically significant associations were observed between dietary vitamin C, vitamin E, and beta-carotene intake and mortality. Overall, greater intake of fruits and vegetables was associated with lower risk of all-cause, cancer, and cardiovascular disease death. These findings support the general health recommendation to consume multiple servings of fruits and vegetables (5-9/day).
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The authors estimated the association between asthma and body mass index in a 1963-2002 study of 135,000 Norwegians aged 14-60 years who were followed on average for 21 years. Cox proportional hazards regression models were fitted to estimate the relative risk of asthma adjusting for smoking, education, and physical activity. Compared with persons with a body mass index (weight (kg)/height (m)(2)) of less than 25, overweight (body mass index: 25-29) men and women had relative risks of asthma of 1.27 (95% confidence interval (CI): 1.13, 1.43) and 1.30 (95% CI: 1.17, 1.45), respectively, while obese (body mass index: >/=30) men and women had relative risks of 1.78 (95% CI: 1.35, 2.34) and 1.99 (95% CI: 1.67, 2.37), respectively. ⋯ In men, the risk of asthma increased by 10% with each unit of increased body mass index between 25 and 30. The similar value for women was 7%. Overweight or obese persons reported asthma more often than did thinner persons after adjustment for smoking, education, and physical activity.