Epidemiology
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Two modeling approaches are commonly used to estimate the associations between neighborhood characteristics and individual-level health outcomes in multilevel studies (subjects within neighborhoods). Random effects models (or mixed models) use maximum likelihood estimation. Population average models typically use a generalized estimating equation (GEE) approach. ⋯ We propose a perspective that treats regression models for what they are in most circumstances: reasonable approximations of some true underlying relationship. We argue in general that mixed models involve unverifiable assumptions on the data-generating distribution, which lead to potentially misleading estimates and biased inference. We conclude that the estimation-equation approach of population average models provides a more useful approximation of the truth.
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Multicenter Study
Use of oral contraceptives in pregnancy and major structural birth defects in offspring.
Oral contraceptives (OCs) are the most commonly used reversible contraceptive method among US women. Although the majority of previous studies have reported no association between OC use during pregnancy and birth defects, some studies have reported increased occurrence of neural tube defects, limb reduction defects, and urinary tract anomalies. ⋯ Previous reports of associations between OC use and specific types of anomalies were not corroborated. Given that associations were assessed for 32 types of birth defects, our findings of 2 increased associations between OC use and gastroschisis and hypoplastic left heart syndrome should be interpreted as hypotheses until they can be evaluated further. Overall, our findings are consistent with the majority of previous studies that found women who use OCs during early pregnancy have no increased risk for most types of major congenital malformations.
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Occupational cohort mortality studies rarely include information on smoking history. Consequently, smoking is often an unmeasured potential confounder in analyses of associations between occupational exposures and lung cancer. Several authors have recommended sensitivity analyses to assess confounding by smoking, which require speculation about the prevalence of smokers in different occupational exposure groups. ⋯ This approach to adjustment for confounding by smoking can be employed without explicitly positing the distribution of smoking with respect to occupational exposure. The approach is easily implemented in analyses of occupational cohort data and should facilitate quantitative assessments of bias due to unmeasured confounding by smoking in occupational studies of lung cancer.
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Historical Article
The ghost of public health journalism: past, present, and future.
The news industry is undergoing shrinking newspaper circulations, cuts in science and health coverage, and expansion of Internet news sources. We examine the impact of these changes using a case study set in Libby, Montana. In 1999, a Seattle newspaper story focused attention on asbestos exposure and related diseases in this small town. ⋯ Environmental Protection Agency issued a public health emergency. Online newspaper archives and a collaboration between the University of Montana's journalism and law schools contributed to coverage of these developments. Continued efforts to promote interest in and skills needed for high-quality public health and environmental reporting are needed.