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.