Abstract
This paper presents a comparison between matched and unmatched respondents in a longitudinal study on alcohol use. Nineteen hundred high school students were twice tested for alcohol use twelve months apart. The questionnaires of 1,446 respondents (76% of the respondents) were successfully matched up by means of a self‐generated code. Four hundred fifty‐four (24%) subjects have dropped out. Prevalence and incidence of alcohol use were assessed by two indices: ever (life time) use and current (last month) use. The major findings were as follows: Dropouts consumed all types of alcoholic beverages at rates considerably exceeding those found among the matched subjects. Also, significant differences were found between dropouts and matched subjects in their sociodemographic background. However, in spite of the differences in alcohol consumption, the same variables‐sensation seeking, gender and age‐explained alcohol use among both groups. The results are discussed in relation to prevention.