Epidemiologic reviews
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Epidemiologic reviews · Jan 2012
Review Meta AnalysisRoadway characteristics and pediatric pedestrian injury.
Changing the built environment is a sound, but often underutilized approach to injury control. The authors reviewed the literature and conducted a meta-analysis to synthesize the evidence on the association of roadway characteristics with risk of pediatric pedestrian injury. To synthesize the data, they converted results to odds ratios based on direct results or abstracted outcomes and used Bayesian meta-analytic approaches by modeling outcomes as the logit of a normally distributed set of outcomes with vague prior distributions for the central measure of effect and its variance. ⋯ The probability of a new study showing an association between the built roadway and pediatric pedestrian injury was nearly 100%. The authors concluded that the built environment is directly related to the risk of pedestrian injury. This review and meta-analysis suggests that even modest interventions to the built roadway environment may result in meaningful reductions in the risk of pediatric pedestrian injury.
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Worldwide, two billion people have been infected with hepatitis B virus (HBV), 360 million have chronic infection, and 600,000 die each year from HBV-related liver disease or hepatocellular carcinoma. This comprehensive review of hepatitis B epidemiology and vaccines focuses on definitive and influential studies and highlights current trends, policies, and directions. HBV can be transmitted vertically, through sexual or household contact, or by unsafe injections, but chronic infections acquired during infancy or childhood account for a disproportionately large share of worldwide morbidity and mortality. ⋯ For example, in Taiwan, the prevalence of chronic infection in children declined by more than 90%. Many resource-poor nations have recently initiated universal hepatitis B immunization programs with assistance from the Global Alliance for Vaccines and Immunization. Further progress towards the elimination of HBV transmission will require sustainable vaccination programs with improved vaccination coverage, practical methods of measuring the impact of vaccination programs, and targeted vaccination efforts for communities at high risk of infection.
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Although the sophistication and flexibility of the statistical technology available to the data analyst have increased, some durable, simple principles remain valid. Hypothesis-driven analyses, which were anticipated and specified in the protocol, must still be kept separate and privileged relative to the important, but risky data mining made possible by modern computers. Analyses that have a firm basis in the randomization are interpreted more easily than those that rely heavily on statistical models. ⋯ Inevitably, such trials will have to deal with more missing data, especially because of dropout and noncompliance. There are fundamental limits on the ability of statistical methods to compensate for such problems, so they must be considered when studies are designed. Finally, it must be emphasized that the availability of software is not a substitute for experience and statistical expertise.