Follow-up contact bias in adolescent substance abuse treatment outcome research.

This study examined the problem of follow-up contact bias in adolescent substance abuse treatment outcome research. The sample consisted of 299 male and female adolescents at an AA-oriented hospital-based inpatient substance abuse treatment program. Six-month and 12-month follow-up data were collected from adolescents and their parents with a sequence of standard and supplementary follow-up data collection procedures. Standard efforts were implemented first and subjects contacted were assigned to the easy-to-contact group. Those subjects not contacted with the initial standard efforts were included in the supplementary effort. Subjects contacted with supplementary efforts constituted the difficult-to-contact group. The difficult-to-contact group exhibited consistently poorer outcomes compared to the easy-to-contact group across most outcome variables and for both follow-up periods. Outcome results from extant studies with a significant number of noncontacted subjects may represent overestimates of outcome and may not be generalizable to the noncontacted group.