The Association between Alcohol Exposure and Self-Reported Health Status: The Effect of Separating Former and Current Drinkers

AIMS To investigate the direction and degree of potential bias introducedto analyses of drinking and health status which exclude former drinkers from exposure groups. DESIGN Pooled analysis of 14 waves (1997-2010) of the U.S. National Health Interview Survey (NHIS). SETTING General population-based study. PARTICIPANTS 404,462 participants, from 14 waves of the NHIS, who had knownself-reported health status and alcohol consumption status. MEASUREMENTS Self-reported health status was used as the indicatorof health. Two approaches were used to classify alcohol consumption: (i) separation of former drinkers and current drinkers, and (ii) combined former and current drinkers. The prevalence of fair/poor health by alcohol use, gender and age with 95% confidence intervals was estimated. The difference in prevalence of fair/poor health status for lifetime abstainers, former drinkers, current drinkers and drinkers (former drinkers and current drinkers combined) were compared using Poisson regression with robust estimations of variance. FINDINGS Excluding former drinkers from drinker groups exaggerates the difference in health status between abstainers and drinkers, especially for males. CONCLUSIONS In cohort study analyses, former drinkers should be assigned to a drinking category based on their previous alcohol consumption patterns and not treated as a discrete exposure group.