US low-risk drinking guidelines: an examination of four alternatives.

BACKGROUND: This study compared four sets of US low-risk drinking guidelines (two interpretations of the US Dietary Guidelines and two variations of the NIAAA physicians' guidelines) in terms of adherence and how well they predicted five different alcohol-related outcomes.
METHODS: Using data from a nationally representative sample of 17,542 US adults 21 years of age and over who drank 12 or more drinks in the past year, this study assessed the sensitivity, specificity, overall accuracy, positive and negative predictive values, and odds ratios of the various drinking guidelines (specifically, of having exceeded them with different degrees of frequency) as predictors of alcohol dependence, impaired driving, liver disease, peptic ulcer, and hypertension.
RESULTS: The proportions of past-year regular drinkers exceeding the four sets of guidelines varied from 20.9%, whose average intake exceeded the weekly limits, to between 21.0% and 42.7% who exceeded the daily guidelines at least once a week, and to between 69.2% and 94.2% who ever exceeded the daily limits in the year preceding the interview. Sensitivity and odds ratios were highest for the ever exceeding the Dietary Guidelines daily limits, intermediate for ever exceeding the two variations based on the NIAAA physicians' guidelines, and lowest for exceeding the Dietary Guidelines interpreted as weekly limits. The opposite pattern was observed for specificity and overall predictive accuracy. When frequently exceeding the daily limits was considered, their sensitivity declined but their specificity and positive predictive value increased.
CONCLUSIONS: If sensitivity and specificity are deemed equally important, the NIAAA physicians' guidelines incorporating both daily and weekly limits seem to do the best job of balancing these dimensions in the prediction of a variety of alcohol-related outcomes.