Good mental health was the only significant factor associated with optimal pill-taking among people taking antiretroviral therapy (ART) for the prevention of sexual transmission of HIV, investigators from the HPTN 052 study report in the online edition of the Journal of Acquired Immune Deficiency Syndromes.
High levels of adherence were observed after one month and one year of follow-up, and – unsurprisingly – people who took 95% of more of their ART doses were more likely to achieve virological suppression.
“The results of this analysis demonstrate a very high degree of adherence to ART, which correlates well with the durable suppression of viremia observed,” comment the authors. “Assessing and intervening on mental health in the context of promoting adherence to ART as prevention should be explored.”
HIV treatment that suppresses viral load is associated with a massive reduction in the risk of transmission to sexual partners. Important information about the effectiveness of virologically suppressive ART on transmission risk came from the HTPN 052 study. This recruited 1763 HIV serodiscordant couples in nine countries. The partners with HIV were randomised to take early (CD4 count 350-550 cells/mm3) or delayed ART. Results showed that early ART reduced the risk of HIV transmission by 96%.
The study investigators wanted to see if factors such as mental health and general wellbeing, substance abuse, binge drinking, social support, sexual behaviour and demographic characteristics such as age, were associated with optimum adherence (taking at least 95% of doses) among the 886 people with HIV randomised to receive early therapy.
Study participants were provided with regular adherence and safer sex counselling. Adherence was assessed using pill count and patient self-report at each study visit. Participants were also asked about their levels of social support and possible reasons for missing doses of their medication. The median duration of follow-up was a little over two years.
On recruitment to the study, 82% of participants said they were very satisfied with their social support, 3% reported substance use and 19% binge drinking. Mental health scores and general health perceptions were within expected ranges.
Measuring adherence by pill count after one month of treatment showed that 82% of participants took all or nearly all their doses. Levels of pill-taking remained stable in the longer-term, with pill counts showing that 83% of individuals were adherent at the one-year follow-up point. Levels of adherence were similarly high when assessed by patient self-report (89% and 84% after one month and one year, respectively).
Common reasons cited by patients for forgetting doses were simple forgetfulness (40-45%), travel away from home (19-23%), busy doing other things (20%) and running out of medication (6-14%).
The investigators’ “univariate” analysis showed that several factors were associated with adherence. When assessed by pill count, these included general health perceptions (p < 0.002), mental health (p < 0.001), reporting safer sex (p = 0.02) and region (Africa or Asia vs the United States; p < 0.002 and p < 0.01, respectively). When assessing adherence by patient self-report, the factors included older age (p = 0.03), mental health (p = 0.005), satisfaction with social support (p = 0.01) and world region (Africa vs United States, p = 0.03).
Subsequent “multivariate” analysis that controlled for potential confounders showed that the only factor associated with excellent adherence was good mental health. This was the case when adherence was assessed using pill count (p = 0.05) and self-report (p = 0.01).
The only significant predictor of viral suppression was an adherence level of at least 95%.
“Adherence to treatment is likely optimized when evidence-based counselling is an ongoing part of the provision of ART,” conclude the investigators.
Safern SA et al. Adherence to early antiretroviral therapy: results from HTPN 052, a phase III multinational randomized trial of ART to prevent HIV-1 sexual transmission in serodiscordant couples. J Acquire Immune Defic Syndr. Online edition, DOI: 10.1097/QAI.0000000000000593 (2015).