Reliability of the timeline follow-back sexual behavior interview

The reliability of self-reported sexual behavior is a question of utmost importance to human immunodeficiency virus (HIV) prevention research. The Timeline Follow-Back (TLFB) interview, which was developed to assess alcohol consumption on the event level, incorporates recall-enhancing techniques that result in reliable information. In this study, the TLFB interview was adapted to assess HIV-related sexual behaviors and their antecedents, and its reliability was assessed. The interview was administered to 110 participants (46% women, M age = 19.7; range = 18-41), and 58 participants who reported sexual behavior during the previous three months returned one week later for a second interview. Test-retest intraclass correlations (p) from the TLFB protocol showed that all sexual behaviors were reported reliably (p range = .86 to .97, median = .96). Bootstrapping, a nonparametric statistical technique, was used for significance testing in the reliability analyses. Reliability was equivalent across each of the three months assessed with the TLFB and was equivalent to conventional assessment methods (i.e. single-item questions). These findings show that the TLFB sexual behavior interview provides reliable reports of sexual behavior over three months and yields event-level data that are extremely valuable for sexual behavior and HIV- prevention research.