Selection biases may lead to systematic overestimate of protective effects from 'moderate' alcohol consumption. Overall, most sources of selection bias favor low-volume drinkers in relation to non-drinkers. Studies that attempt to address these types of bias generally find attenuated or non-significant relationships between low-volume alcohol consumption and cardiovascular disease, which is the major source of possible protective effects on mortality from low-volume consumption. Furthermore, observed mortality effects among established low-volume consumers are of limited relevance to health-related decisions about whether to initiate consumption or to continue drinking purposefully into old age. Short of randomized trials with mortality end-points, there are a number of approaches that can minimize selection bias involving low-volume alcohol consumption.
BACKGROUND: A large body of research suggests that light or moderate alcohol consumption is associated with reduced all-cause mortality. However, concerns remain that the observed relationship is due to selection bias, misclassification of ex-drinkers, or residual confounding.
METHODS: The association between alcohol consumption and all-cause mortality was analyzed using Cox regression. The analysis was performed using data from the Health and Retirement Study, a longitudinal cohort of 24,029 individuals from a nationally representative sample of US adults aged more than 50 years. Drinking level was based on alcohol consumption measured at 3 points over the 4 years before the start of follow-up. Occasional drinkers-those who reported drinking on at least 1 occasion, but always less than once per week-served as the reference category. There was extensive adjustment for sociodemographic variables, health status, and functional status.
RESULTS: During 206,966 person-years of follow up, 7902 individuals died. No level of regular alcohol consumption was associated with reduced all-cause mortality. The hazard ratio and 95% confidence interval in fully adjusted analyses was 1.02 (0.94-1.11) for /=21 drinks/week.
CONCLUSIONS: Moderate alcohol consumption is not associated with reduced all-cause mortality in older adults. The previously observed association may have been due to residual confounding.
BACKGROUND: Prior research examining the association between retirement and alcohol consumption is inconsistent with respect to salience, direction and magnitude. Reasonable conceptual arguments for both positive (e.g. coping, introduction of leisure time) and negative (e.g. severance of work-related social relationships) changes further complicate investigations of this critical association, as do differences in study design, national setting and measurement of alcohol use.
METHODS: This prospective longitudinal study analyses 2-year wave-pairs drawn from seven waves (14 years) of data from the US Health and Retirement Study to assess the effect of complete retirement on weekly alcohol consumption (n = 9979 observations; 4674 unique participants). We use multiple regression analysis in a two-period follow-up design and account for potential selection bias and reverse causality not addressed in prior research on this topic.
RESULTS: We find that retirement is positively associated with subsequent weekly alcohol consumption for men who reported drinking at both follow-up and the prior study wave (beta = 1.9, 95% confidence interval = 0.43-3.36). No association was observed among women.
CONCLUSION: Our results suggest that health care professionals should monitor the drinking habits of retired men, as older individuals are particularly susceptible to the adverse effects of heavy alcohol use.