Comparison of assessment methods for self-reported alcohol consumption in health interview surveys

OBJECTIVE: To select a simple method for assessing alcohol consumption and to compare how different reference periods and response categories influence the self-reported frequency of binge drinking. DESIGN: Four random samples of 1000 adult Danes. Data were collected via personal interview at the respondents' home. SETTING: Denmark, nationwide. PARTICIPANTS: The total number of interviewed was 2593 individuals. MEASUREMENTS: The assessment methods in the four samples were (1) the 7-day recall method, (2) intake each day in a typical week, (3) intake last weekend, and (4) intake in a typical week. Furthermore, binge drinking was assessed in the samples using different reference periods and response formats. FINDINGS: The sex- and age-adjusted mean number of drinks in the last week (the 7-day recall method) was 10.6 drinks compared to 10.4 drinks among respondents reporting their intake for each day in a typical week and 8.7 drinks among subjects reporting the average intake in a typical week. Furthermore, subjects that reported their typical intake for each day were as likely as subjects that had the 7-day recall method to report a high weekly alcohol intake. Respondents who had close-ended questions were more likely to report binge drinking compared to respondents that had open-ended questions. CONCLUSIONS: Questions concerning typical alcohol intake for each day of the week are feasible to use in epidemiological studies. Furthermore, it is more appropriate to use close-ended questions compared to open-ended questions in measuring binge-drinking when the reference period is long.