ART adherence in first four months predicts long-term viral suppression in 12-year study

Good adherence during the first four months of ART makes long-term undetectable viral load more than three times more likely according to results from a French cohort study published in the Journal of AIDS.

Camelia Protopopescu al from INSERM, Marseille and colleagues recruited people in the APROCO-COPILOTE cohort, a French multicentre prospective, observational study of HIV positive people who initiated ART between 1997 and 1999 with 12 years follow up.

Standardised self-administered questionnaires were used to collect data on adherence to ART at month 1, 4 and then every 8/12 months until month 144. Adherence was scored based on adherence over the previous four days and was graded as: high (100%); medium (80–99.9%); and low (less than 80%). Given that previously published analysis of this cohort had revealed that 80% of participants achieved viral suppression by month 4, this time point was therefore used for assessment of “early adherence”. “Maintenance adherence” was subsequently evaluated at each visit from 1 year to 12 years (months 12 to 144).

“Prolonged viral suppression” (PVS) was defined as maintaining an undetectable viral load for all three of the most recent visits, including the current one. As PVS required three consecutive visits at four-month intervals, the study period for maintenance adherence started 8 months after month 12, i.e. from months 20 to 144.

The study followed 891 participants who had at least one assessment of both maintenance adherence and PVS and who were followed for a median of 11 (IQR 5.3 to 12) years. At baseline, median CD4 count was 286 (IQR 141-429) and 20% has a diagnosis of AIDS.

The percentage of participants with PVS increased over the course of follow up visits, from 48% of 687 participants with available data at month 20, to 74% of 429 participants at month 132 (median follow up duration) to 73% of 229 participants at month 144.

Early adherence at month 4 was high for 57% of participants, medium for 33% of participants and low for 10% of participants. Maintenance adherence for the follow up period from month 20-144 was high at all visits for 66% of participants, fluctuating between medium and high, but never low, for 25% of participants and at least one episode of being low for 9% of participants.

Long term PVS was significantly associated with early adherence patterns that were high (adj. OD 3.72; 95%CI: 1.98 to 6.98) or medium (adj. OD 1.98; 95%CI: 1.02 to 3.83) versus low. In multivariate analysis, this association remained high even after adjusting for the month 20 to 144 time-varying maintenance adherence patterns “always high adherence” (adj. OD 3.28; 95%CI: 2.64 to 4.08) and “adherence fluctuating between medium and high” (adj. OD 2.26; 95%CI: 1.81 to 2.83) versus low. Other factors independently associated with PVS included older age, birth within the EU and a viral load <500 copies/mL at month one.

This reports suggests that adherence in the first 4 months of ART is a significant predictor of long-term prolonged viral suppression. The authors also draw attention to the finding that migrants born outside the EU are less likely to achieve PVS and suggest that this group is more likely to present with advanced HIV infection and lower CD4 counts at HIV diagnosis. This stresses the need for special attention to adherence support in migrant populations.

Protopopescu C et al. Prolonged viral suppression over a 12-year follow-up of HIV-infected patients: the persistent impact of adherence at 4 months after initiation of combined antiretroviral therapy in the ANRS CO8 APROCO-COPILOTE cohort. JAIDS (2017) EPub Ahead of Print DOI: 10.1097/QAI.0000000000001249.
https://www.ncbi.nlm.nih.gov/pubmed/27861235