Increased long-term mortality among survivors of acute carbon monoxide poisoning.

Objective: Recent data suggest that patients surviving acute carbon monoxide (CO) poisoning (COP) may have increased risk for long-term mortality. The objective of this study was to analyze long-term mortality of a large population of CO-poisoned patients treated at one medical center over three decades.

Design: Retrospective cohort study of patients treated with hyperbaric oxygen and surviving the acute poisoning episode.

National surveillance for asthma--United States, 1980-2004.

Problem/condition: Asthma, a chronic respiratory disease with episodic symptoms, increased in prevalence during 1980-1996 in the United States. Asthma has been the focus of numerous provider interventions (e.g.

Asthma incidence: data from the National Health Interview Survey, 1980-1996.

Objective: To obtain historical estimates of US asthma incidence from 17 years of health survey data.

Methods: The 1980 through 1996 National Health Interview Survey contained a question asking about the time of asthma onset in persons with asthma. Annual past year incidence estimates were calculated from self-reports of asthma status.

The geography of power: statistical performance of tests of clusters and clustering in heterogeneous populations.

Heterogeneous population densities complicate comparisons of statistical power between hypothesis tests evaluating spatial clusters or clustering of disease. Specifically, the location of a cluster within a heterogeneously distributed population at risk impacts power properties, complicating comparisons of tests, and allowing one to map spatial variations in statistical power for different tests. Such maps provide insight into the overall power of a particular test, and also indicate areas within the study area where tests are more or less likely to detect the same local increase in relative risk.