Studies on natural recovery from alcohol dependence: sample selection biasby media solicitation?

Aims. To assess the selection bias of recruiting participants in studies on natural recovery from alcohol dependence through media solicitation. Desig n. Two samples with different recruitment strategies are compared. Setting. Media solicitation and general population. Participants. Sample I consists of 176 alcohol-dependent individuals remitted without formal help and recr uited through media solicatation, sample 2 consists of 32 natural remitters derived from a representative general population study with a sample size of 4075 respondents and a response rate of 70.2%. Measurements. Several tri ggering mechanisms and maintenance factors of remission were assessed in a personal interview using standardized questionnaires. Findings. Results of logistic regression analyses show that media-solicited subjects were more o ften abstinent in the last 12 months, were more severely dependent, were le ss satisfied with eight life domains prior to remission and showed higher s cores in a coping behaviour measure. Besides these major differences from t he multivariate analysis, media subjects revealed more health problems prio r to remission, experienced more social pressure to change drinking behavio ur, and showed differences in reasons for not seeking help. Conclusions. Me dia solicitation leads to a sample selection bias in research an natural re covery from alcohol dependence. When measures to foster self-change are der ived from such studies, findings from representative samples have to be con sidered.