Cognitive-behavioral intervention to enhance adherence to antiretroviral therapy: a randomized controlled trial (CCTG 578)

Objective: We conducted a randomized, multi-site, controlled trial of a cognitive-behavioral adherence intervention for patients initiating or changing an antiretroviral (ART) regimen. Design: A 3 x 2 factorial design was used with the primary randomization assigning patients (I : I : 1) to one of two adherence interventions or usual care. Methods: The five-session adherence interventions consisted of cognitive-behavioral and motivational components, with or without a 2-week pre-treatment placebo practice trial. Intent-to-treat analysis used probability weights and regression tree analysis to account for missing data. Results: A total of 230 patients were randomized; 199 started ART, of whom 74% completed the 48-week study. Electronic monitored adherence outcomes between the two intervention groups did not differ significantly and were thus pooled in analyses. At week 4, 82% of intervention patients had taken at least 90% of their prescribed ART doses, compared with 65% of controls (P < 0.01); this group difference dropped to 12% at week 12 (72 versus 60%; P = 0.15) and 11 % at week 24 (66 versus 55%; P = 0.28). Mean adherence in the intervention group was significantly higher than the control group at week 24 (89 versus 81 %; P < 0.05) only. There were no group differences with respect to HIV-1 RNA throughout the study. Conclusions: The effects of the cognitive-behavioral intervention on adherence were modest and transient, and no effects were observed on viral load or CD4 cell count. More robust effects may require a more intense intervention that combines ongoing adherence monitoring and individualized intervention 'dosage' that matches the need and performance of each patient. (c) 2006 Lippincott Williams & Wilkins.