Using state-issued identification cards for obesity tracking.

Obesity prevention has emerged as one of public health's top priorities. Public health agencies need reliable data on population health status to guide prevention efforts. Existing survey data sources provide county-level estimates; obtaining sub-county estimates from survey data can be prohibitively expensive. State-issued identification cards are an alternate data source for community-level obesity estimates. We computed body mass index for 3.2 million adult Oregonians who were issued a driver license or identification card between 2003 and 2010. Statewide estimates of obesity prevalence and average body mass index were compared to the Oregon Behavioral Risk Factor Surveillance System (BRFSS). After geocoding addresses we calculated average adult body mass index for every census tract and block group in the state. Sub-county estimates reveal striking patterns in the population's weight status. Annual obesity prevalence estimates from identification cards averaged 18% lower than the BRFSS for men and 31% lower for women. Body mass index estimates averaged 2% lower than the BRFSS for men and 5% lower for women. Identification card records are a promising data source to augment tracking of obesity. People do tend to misrepresent their weight, but the consistent bias does not obscure patterns and trends. Large numbers of records allow for stable estimates for small geographic areas.

Evaluation of a heat vulnerability index on abnormally hot days: an environmental public health tracking study.

BACKGROUND: Extreme hot weather conditions have been associated with increased morbidity and mortality, but risks are not evenly distributed throughout the population. Previously, a heat vulnerability index (HVI) was created to geographically locate populations with increased vulnerability to heat in metropolitan areas throughout the United States. OBJECTIVES: We sought to determine whether areas with higher heat vulnerability, as characterized by the HVI, experienced higher rates of morbidity and mortality on abnormally hot days. METHODS: We used Poisson regression to model the interaction of HVI and deviant days (days whose deviation of maximum temperature from the 30-year normal maximum temperature is at or above the 95th percentile) on hospitalization and mortality counts in five states participating in the Environmental Public Health Tracking Network for the years 2000 through 2007. RESULTS: The HVI was associated with higher hospitalization and mortality rates in all states on both normal days and deviant days. However, associations were significantly stronger (interaction p-value < 0.05) on deviant days for heat-related illness, acute renal failure, electrolyte imbalance, and nephritis in California, heat-related illness in Washington, all-cause mortality in New Mexico, and respiratory hospitalizations in Massachusetts. CONCLUSION: Our results suggest that the HVI may be a marker of health vulnerability in general, although it may indicate greater vulnerability to heat in some cases.