The Reply

Abstract

I would like to thank Keller for his comments on my paper on the association between alcohol use and mortality among participants in the Health and Retirement Study.1Goulden R. Moderate alcohol consumption is not associated with reduced all-cause mortality.Am J Med. 2016; 129 (180.e4-186.e4)Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar Keller raises the possibility that the “occasional drinkers” group is, in fact, a group of light drinkers who have under-reported their level of consumption. If this is indeed the case for all “occasional drinkers,” he is correct to note that the study's findings are consistent with the previously reported J-shaped association between alcohol use and all-cause mortality. Without objective measurements of alcohol intake among Health and Retirement Study participants, this interpretation cannot be definitively refuted. However, even if we assume that only half of the “occasional drinkers” have accurately reported that they drink less than once per week—a level for which a significant beneficial effect of alcohol on mortality seems biologically implausible—one would still expect to see some evidence of benefit, if it truly exists, among the regular light drinkers group, assuming that there is minimal over-reporting of consumption and that they do indeed all drink regularly. Instead, the point estimate for the fully adjusted hazard ratio for light drinkers (vs occasional drinkers) is 1.02 (95% confidence interval, 0.94-1.11), strongly suggesting no effect. Research in other population groups comparing self-reported alcohol consumption with external verification have generally found good levels of concordance.2Babor T.F. Steinberg K. Anton R. Del Boca F. Talk is cheap: measuring drinking outcomes in clinical trials.J Stud Alcohol. 2000; 61: 55-63Crossref PubMed Scopus (428) Google Scholar, 3Chermack S.T. Singer K. Beresford T.P. Screening for alcoholism among medical inpatients: how important is corroboration of patient self-report?.Alcohol Clin Exp Res. 1998; 22: 1393-1398Crossref PubMed Scopus (62) Google Scholar However, the extent to which these findings were influenced by participants being aware of external verification is difficult to determine.4Del Boca F.K. Darkes J. The validity of self-reports of alcohol consumption: state of the science and challenges for research.Addiction. 2003; 98: 1-12Crossref PubMed Scopus (843) Google Scholar I agree with Keller that a randomized controlled trial of moderate alcohol use is the only way to definitively evaluate its effects on health. A recent, 2-year randomized trial looking at alcohol's effects on surrogate markers of cardiovascular disease in diabetic patients suggests such a trial is feasible.5Gepner Y. Golan R. Harman-Boehm I. et al.Effects of initiating moderate alcohol intake on cardiometabolic risk in adults with type 2 diabetes: a 2-year randomized, controlled trial.Ann Intern Med. 2015; 163: 569-579Crossref PubMed Scopus (127) Google Scholar If the benefits of light/moderate alcohol consumption are indeed of the magnitude suggested by previous observational research—a 10%-20% reduction in all-cause mortality6Di Castelnuovo A. Costanzo S. Bagnardi V. Donati M. Iacoviello L. de Gaetano G. Alcohol dosing and total mortality in men and women: an updated meta-analysis of 34 prospective studies.Arch Intern Med. 2006; 166: 2437-2445Crossref PubMed Scopus (710) Google Scholar, 7Jayasekara H. English D.R. Room R. MacInnis R.J. Alcohol consumption over time and risk of death: a systematic review and meta-analysis.Am J Epidemiol. 2014; 179: 1049-1059Crossref PubMed Scopus (68) Google Scholar—this would make ethanol a dramatically effective drug. I remain skeptical that such a large effect exists. Benefits of Moderate Alcohol Consumption Not DisprovenThe American Journal of MedicineVol. 129Issue 8PreviewGoulden's1 conclusion that moderate alcohol consumption is not associated with reduced all-cause mortality in older adults conflicts with the findings of other studies, which he attributes mainly to residual confounding and bias. However, Goulden's own Table 2 indicates that regular drinkers who consume less than 7 drinks per week (whom I shall call “light drinkers”) actually do exhibit the lowest average mortality hazard ratio (HR), compared with nondrinkers or heavy drinkers (>21 drinks per week), even when fully adjusted by Goulden, for all 11 categories of subjects, based on age, sex, health, socioeconomic, and functional status. Full-Text PDF