Screening for alcohol dependence and abuse in women: description, validation, and psychometric properties of a new screening instrument, SWAG, in a population study.

In this study, we have evaluated the use of a screening instrument in the first phase of a population study of female alcoholism and alcohol problems. The instrument, called SWAG (Screening, Women, and Alcohol in Göteborg), is a 13-item questionnaire. It includes a modified version of CAGE. The study sample consisted of 3,130 women. Of these, a stratified sample of 479 were invited for interview. Validation was done against interview-based clinical diagnosis according to DSM-III-R (alcohol dependence and abuse), with additional use of medical record information. SWAG had similar sensitivity and specificity used on a population sample, as previously has been found for alcohol problem screening instruments tested in clinical settings. Positive predictive value, rarely reported in studies of other alcohol screening instruments, was 40 to 50%. With logistic regression, we developed a promising set of criteria, called SWAG-L, that had similar sensitivity, specificity, and positive predictive value as the longer version SWAG-1, at the same time it consisted of only four items. CAGE had considerably lower sensitivity than SWAG. SWAG can, so far, be recommended for use in epidemiological studies. It may also prove valuable in clinical settings, although that requires a different scoring method. The question, "I have/have had alcohol problems" was the single item that best predicted alcohol dependence and abuse.