Use of Unannounced Telephone Pill Counts to Measure Medication Adherence Among Adolescents and Young Adults Living With Perinatal HIV Infection.

Objective: To examine unannounced telephone pill counts as a measure of adherence to antiretroviral therapy among adolescents and young adults living with perinatal HIV infection.

Methods: Participants were recruited from an ongoing longitudinal study to complete four monthly, unannounced telephone pill counts. Detailed notes concerning participants' medication habits surrounding adherence were recorded.

Results: Two-thirds of 102 eligible participants aged 18-27 years participated; 57% were female, 69% were Black. Blacks and participants with viral loads >40 and >1,000 copies/ml were less likely to participate. Average adherence across calls was 77%. Those who completed all calls averaged significantly higher adherence scores than those who did not. Calls revealed adherence barriers at individual (e.g., medication disorganization), social (e.g., limited support), and system (e.g., pharmacy problems) levels.

Conclusions: Despite challenges, this procedure can be implemented with this population and can help identify adherence barriers important for interventions that address medication-taking behaviors.