American journal of epidemiology
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In this article, the authors demonstrate a time-series analysis based on a hierarchical Bayesian model of a Poisson outcome with an excessive number of zeroes. The motivating example for this analysis comes from the intensive care unit (ICU) of an urban university teaching hospital (New Haven, Connecticut, 2002-2004). Studies of medication use among older patients in the ICU are complicated by statistical factors such as an excessive number of zero doses, periodicity, and within-person autocorrelation. ⋯ By applying elements of time-series analysis within both frequentist and Bayesian frameworks, the authors evaluate differences in shift-based dosing of medication in a medical ICU. From a small sample and with adjustment for excess zeroes, linear trend, autocorrelation, and clinical covariates, both frequentist and Bayesian models provide evidence of a significant association between a specific nursing shift and dosing level of a sedative medication. Furthermore, the posterior distributions from a Bayesian random-effects Poisson model permit posterior predictive simulations of related results that are potentially difficult to model.
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In 1949, Alexander Langmuir became the first chief epidemiologist at the Communicable Disease Center (CDC) in Atlanta, Georgia. Among his many contributions to the agency and to public health, 2 of the most important--the Epidemic Intelligence Service (EIS) and his particular brand of epidemic-assistance investigation (the Epi-Aid)--are highlighted in this supplement to the American Journal of Epidemiology. ⋯ Support to state and local health departments has been instrumental to CDC's success during its first 60 years, and the articles describing Epi-Aids in this supplement capture this partnership elegantly. They also reflect the evolution of CDC from an agency focused almost entirely on communicable diseases to one engaged in a broad array of global public health challenges.
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Knowledge of the association between body mass index (weight (kg)/height (m)(2)) and premature death in young adulthood is very limited, especially for specific causes of death. Using the US National Health Interview Survey linked mortality files, the authors examined the relation between body mass index and premature death from all causes, cardiovascular disease (CVD), and cancer among 112,328 persons aged 18-39 years who participated in the National Health Interview Survey in the years 1987, 1988, and 1990-1995. During an average of 16 years of follow-up (ending on December 31, 2006), there were 3,178 deaths: 573 from CVD and 733 from cancer. ⋯ In analyses restricted to participants who had never smoked, the hazard ratios for death from all causes were 1.07 (95% confidence interval (CI): 0.91, 1.26) for overweight participants, 1.41 (95% CI: 1.16, 1.73) for obese participants, and 2.46 (95% CI: 1.91, 3.16) for extremely obese participants, compared with those of normal weight. Monotonically increasing risks for excess body weight were also observed for deaths from cancer and CVD. The associations found in this young cohort were much stronger than those in middle-aged or older populations.
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Chronic musculoskeletal pain constitutes a large socioeconomic challenge, and preventive measures with documented effects are warranted. The authors' aim in this study was to prospectively investigate the association between physical exercise, body mass index (BMI), and risk of chronic pain in the low back and neck/shoulders. The study comprised data on approximately 30,000 women and men in the Nord-Trøndelag Health Study (Norway) who reported no pain or physical impairment at baseline in 1984-1986. ⋯ Obese women and men had an approximately 20% increased risk of chronic pain in both the low back and the neck/shoulders. Exercising for 1 or more hours per week compensated, to some extent, for the adverse effect of high BMI on risk of chronic pain. The authors conclude that physical inactivity and high BMI are associated with an increased risk of chronic pain in the low back and neck/shoulders in the general adult population.
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Data indicate an inverse association between dietary calcium and magnesium intakes and blood pressure (BP); however, much less is known about associations between urinary calcium and magnesium excretion and BP in general populations. The authors assessed the relation of BP to 24-hour excretion of calcium and magnesium in 2 cross-sectional studies. The International Study of Macro- and Micro-Nutrients and Blood Pressure (INTERMAP) comprised 4,679 persons aged 40-59 years from 17 population samples in China, Japan, the United Kingdom, and the United States, and the International Cooperative Study on Salt, Other Factors, and Blood Pressure (INTERSALT) comprised 10,067 persons aged 20-59 years from 52 samples around the world. ⋯ Qualitatively similar associations were observed in INTERSALT analyses. Associations between magnesium excretion and BP were small and nonsignificant for most of the models examined. The present data suggest that altered calcium homoeostasis, as exhibited by increased calcium excretion, is associated with higher BP levels.