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 × 2 factorial design was used with the primary randomization assigning patients (1: 1: 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.
From the aRAND Corporation, Santa Monica
bLos Angeles Biomedical Research Institute at Harbor-UCLA Medical Center and the David Geffen School of Medicine at UCLA, Torrance
cUniversity of California Irvine, Irvine
dSanta Clara Valley Medical Center, San Jose
eUniversity of Southern California- Los Angeles County Medical Center, Los Angeles
fUniversity of California San Diego, San Diego, California, USA.
Received 14 December, 2005
Revised 20 February, 2006
Accepted 23 March, 2006
Correspondence to Glenn Wagner PhD, RAND, 1776 Main St., Santa Monica, CA 90407, USA. E-mail: firstname.lastname@example.org