Understanding acceptance of and adherence to a new formulation of paediatric antiretroviral treatment in the form of pellets (LPV/r)—A realist evaluation

Background Improving access to paediatric HIV treatment requires large-scale antiretroviral treatment programmes and medication adapted to infants and children’s needs. The World Health Organisation recommends lopinavir/ritonavir plus two nucleoside reverse transcriptase inhibitors as first-line treatment for all HIV-infected children younger than three years, usually given as a syrup. A pellet formulation (i.e. tiny cylinders of compressed medication put in capsules) was developed to overcome the syrup formulation’s disadvantages such as bitterness, toxicity and cold storage. This study assessed multi-level factors influencing caregivers’ acceptance of and adherence to lopinavir/ritonavir pellets as well as their underlying mechanisms. Methods A realist evaluation (a theory-driven evaluation method considering the social context and mechanisms of change), embedded in a clinical trial was carried out in three hospital settings in Kenya. Data were collected through document review, observations (n = 34) in home and clinic settings and semi-structured interviews (n = 44) with caregivers and providers. Data analysis was based on realist principles. Results High levels of treatment initiation and adherence were observed. Taste masking, neutral packaging and easy storage made the new formulation highly acceptable. Caregivers developed individual strategies to deliver the treatment, particularly to overcome specific problems e.g. in case of just-weaned babies or food shortage. A refined program theory emerged from the triangulated findings showing that ease of administration combined with increased self-efficacy and competences of the caregivers, and effective provider support contributed to high levels of adherence. Conclusions Formulating combined antiretroviral treatment in the form of pellets is clearly a more acceptable solution for infants and children and their caregivers compared to the syrup. Further research in non-trial settings may shed light on factors related to providers, services and the health system that contribute to better adherence of such formulations.