Rate of decay in proportion of condom-protected sex acts among adolescents after participation in an HIV risk-reduction intervention.

objectiveHIV risk-reduction interventions have demonstrated efficacy in enhancing the proportion of condom-protected sex (CPS) acts among diverse populations. Although postintervention exposure increase in CPS are often observed, there is scant empirical data quantifying decay of intervention efficacy (declines in CPS after cessation of the intervention among participants reporting an initial postintervention increase in CPS). Thus, the objective of this study was to quantify the rate of decay in intervention efficacy over a 24-month follow-up.

designAfrican American adolescent females (ages: 14-20; n = 349) completed a baseline audio computer-assisted self-administered interview, participated in an HIV risk-reduction intervention, and were assessed at 6-month intervals for 24 months postintervention. Intervention efficacy was conceptualized as an increase in participants' CPS relative to baseline.

methodsAnalyses focused on the subset of participants who reported an initial increase in CPS from baseline to the 6-month postintervention assessment (n = 121) to quantify the rate of decay in intervention efficacy over a 24-month follow-up period.

resultsCPS increased markedly from baseline to 6-month follow-up assessment. However, from 6 to 12 months, a marked decline in CPS was observed. Further CPS declines, though not statistically significant, were observed from 12 to 18 months and 18 to 24 months. Cumulative reductions in CPS over the entire 24-month follow-up resulted in no statistical difference between baseline and 24-month follow-up; indicative of a nonsignificant intervention effect at 24-month assessment.

conclusionsInnovative postintervention optimization strategies are needed to minimize CPS decay over protracted time periods by reinforcing, sustaining, and potentially amplifying initial gains in condom use.