Improving the Validity of the Behavioral Risk Factor Surveillance System Alcohol Measures.

BACKGROUND

Valid measurement of alcohol use can be difficult in surveys, which are subject to biases like underreporting and differential nonresponse. Still, monitoring trends, policy impacts, disparities, and related issues all require valid individual- and state-level drinking data collected over time. Here, we propose a double-adjustment approach for improving the validity of the Behavioral Risk Factor Surveillance System (BRFSS) alcohol measures.

METHODS

Validity analyses of the 1999 to 2016 BRFSS, a general population survey of U.S. adults. Measures are aggregated to state level for N = 918 observations, single-adjusted for BRFSS methodologic changes, and double-adjusted by per capita consumption. Fixed-effects models: (i) assess predictive validity using adjusted BRFSS drink volume to predict mortality outcomes and (ii) assess outcome validity using state-level alcohol taxes to predict adjusted BRFSS volume.

RESULTS

Neither the raw nor the single-adjusted BRFSS drinking measures were related to mortality in the expected direction, while double-adjusted BRFSS volume and 5+ days were significantly positively related to mortality, as expected. Spirits and beer taxes were not related to single-adjusted BRFSS drinking in the expected direction. However, spirits and beer taxes were both significantly related to double-adjusted BRFSS volume in the expected directions.

CONCLUSIONS

Future studies should consider using the double-adjusted BRFSS measures to ensure the validity of drinking survey data in analyses where variation over time is considered.