Ensuring Retention in Longitudinal Studies: A Practical Evaluation of an Intensive Follow-up Protocol and Suggested Adaptations.

Ensuring retention in longitudinal studies of individuals with substance use disorders (SUD) is a continual challenge for researchers. This study made several modifications to a highly intensive follow-up protocol (Scott, 2004), originally designed for adults with SUD, in order to adapt it to a group of adolescents in low-intensity outpatient SUD treatment ( = 127, age 16.7 yrs) and to accommodate limitations in the financial resources available for study staffing and transportation. In the present sample, adolescent participants generally found it unreasonable for study staff to request to contact people outside their immediate family in order to locate them and to attempt to schedule interviews 3-6 months in advance, as specified in the original protocol. Changes were made to accommodate these concerns and follow-up rates remained high (85-91%). Even though this study is limited by its non-experimental nature, it provides a replicable example of a scaled-down, less costly version of a highly intensive follow-up protocol that can be used to achieve high follow-up rates in studies of adolescents with SUD. We hope this will be encouraging for researchers and program evaluators who have limited resources or who work with participants who express concerns about privacy or study burden.