Test-retest reliability and validity of life-course alcohol consumption measures: the 2005 National Alcohol Survey follow-up.

BACKGROUND

Few studies assess reliability and validity of lifetime alcohol measures. We undertook extended test-retest analyses of retrospective lifetime drinking measures and of incremental predictive ability of lifetime heavy drinking (days 5+ drinks) in teens, 20s, and 30s for current (12-month) alcohol use disorders (AUDs).

METHODS

A subset (31.4%; 962 men, 1,220 women) of the 2005 U.S. National Alcohol Survey (NAS; N11) completed a follow-up survey (N11T) by phone or mail (mean delay of 2.7 years). Both surveys assessed lifetime drinking.

RESULTS

In N11T, drinking status was reported consistently by 94.7% of N11 current drinkers, 85.5% of ex-drinkers, and 74.4% of lifetime abstainers (93.5% overall). Cumulative number of prior heavy drinking days (teens through 30s) were moderately consistent (Pearson's ρ = 0.6, p < 0.001, n = 1,636). Reliability was lower for younger respondents under 30 and higher for Whites versus Blacks and Hispanics (ρ = 0.68 vs. ρ = 0.56 vs. ρ = 0.56, both p = 0.01), but did not differ by gender. Heavy drinking days in teens correlated 0.63 (p < 0.001) for those aged 20 or older, higher for women than men and for Whites versus ethnic minorities. Heavy drinking days in the 20s and 30s reported by those 30 and older and 40 and older correlated at 0.63 and 0.67, respectively, being higher for Whites. Age of drinking onset and of lifetime maximum quantity reports were also consistent (0.65, 0.73), higher for women versus men, for those older than 29 versus younger, and for Whites versus Blacks and Hispanics. In N11, controlling for gender, age, ethnicity, and current 5+ frequency, cumulative prior 5+ days (teens to age 39) predicted current alcohol-related consequences and dependence (both p = 0.003).

CONCLUSIONS

Measurements of earlier heavy drinking are feasible, efficient, and reasonably reliable, albeit with some individual imprecision. Prior drinking data improve prediction of current AUDs, adjusting for demographics and current drinking.