Background: High levels of adherence to antiretroviral therapy are considered necessary to achieve viral suppression. We analyzed data from a cohort of HIV-infected children who were <2 years of age receiving protease inhibitor–based antiretroviral therapy to investigate associations between viral suppression and adherence ascertained using different methods.
Methods: Data were from the prerandomization phase of a clinical trial in South Africa of HIV-infected children initiating either ritonavir-boosted lopinavir (LPV/r) or ritonavir-based antiretroviral therapy. At scheduled visits during the first 24 weeks of enrollment, study pharmacists measured quantities of medications returned to the clinic. Caregivers answered questionnaires on missed doses and adherence barriers. Associations between adherence and viral suppression (HIV-1 RNA <400 copies/mL) were investigated by regimen.
Results: By 24 weeks, 197 of the 269 (73%) children achieved viral suppression. There was no association between viral suppression and caregiver reported missed doses or adherence barriers. For children receiving the LPV/r-based regimen, medication return adherence to each of the 3 drugs in the regimen (LPV/r, lamivudine or stavudine) individually or together was associated with viral suppression at different adherence thresholds. For example, <85% adherence to any of the 3 medications significantly increased odds of lack of viral suppression (odds ratio: 2.30, 95% confidence interval: 1.30–4.07, P = 0.004). In contrast, for children receiving the ritonavir-based regimen, there was no consistent pattern of association between medication return and viral suppression.
Conclusions: Caregiver reports of missed doses did not predict virologic response to treatment. Pharmacist medication reconciliation correlated strongly with virologic response for children taking a LPV/r-based regimen and appears to be a valid method for measuring pediatric adherence.