Secular trends in the lifetime prevalence of alcohol dependence in the United States: a re-evaluation

Abstract

Background: U.S. epidemiologic surveys have consistently found higher lifetime prevalence of alcohol dependence among younger subjects than among older groups. Because lifetime prevalence is cumulative, such patterns are suggestive of strong secular trends; i.e., more-recently born subjects have developed more disease in a shorter period of time than their elders. However, it remains unclear whether such patterns truly reflect secular trends or are confounded by age-dependent factors such as differential recall, differential mortality, and other effects.

Methods: Using data from 2 large, national epidemiological surveys, a repeated cross-sectional analysis was conducted to compare lifetime prevalence of alcohol dependence across temporally adjacent birth cohorts surveyed at the same age, thus enabling estimates of cross-cohort differences while controlling for age-related factors.

Results: In contrast with results from single cross-sectional analyses, there were few significant cross-cohort differences among groups of men compared at similar ages. On the other hand, women born between 1954 and 1963 were at 1.2-fold higher odds for lifetime drinking, and those who drank were at 1.5-fold higher odds for lifetime alcohol dependence, compared with the immediately preceding birth cohort (1944 to 1953). The 1944 to 1953 cohort was also at elevated odds for lifetime drinking compared with their predecessors (1934 to 1943). These results were largely due to changes among White and Hispanic women.

Conclusions: These results suggest that there have been substantial secular increases in drinking and alcohol dependence among women, but not men. Analyses of single cross-sectional studies may tend to over-estimate secular trends by failing to account for age-dependent effects. Nonetheless, secular increases in drinking and alcohol dependence among women are evident after taking age-related factors into account.

Figure 1

Schematic illustration of cross-survey comparisons. Dashed line corresponds to comparisons of the same birth cohort at different ages (Intra-cohort comparisons, Table 1), which assesses the magnitude of age-related effects on reported prevalence. Solid lines correspond to age-matched comparisons of temporally adjacent birth cohorts (Cross-cohort comparisons, Tables 2 and 3), which are used to provide data on differences in lifetime prevalence between birth cohorts, while controlling for the effects of age by comparing similarly aged cohorts.