Abstract
OBJECTIVE: Non-adherence to antidepressants has been linked to increased symptom severity, relapse and hospitalisation from common mental disorders. However, there is limited knowledge of factors associated with antidepressant adherence in low-income and middle-income countries, especially in public sector, primary care settings. METHODS: We quantified fluoxetine adherence using the medication possession ratio. A limitation of this measure is that it does not always reflect the ingestion of medication. We constructed a generalised estimating equations linear regression with robust SEs, clustered by the participant, to identify independent predictors of fluoxetine adherence. RESULTS: Participants randomised to fluoxetine were dispensed an average of 126 daily doses, or 70% of the 180 possible doses. Adherence was higher in the first half of the treatment period at 86.3%, 95% CI (83.5% to 89.2%) compared with 46.5% in the second half (44.3% to 48.8%) (p<0.001). Participants who opted for community-delivered fluoxetine demonstrated adherence at 79.7% (77.0% to 82.4%) compared with 58.6% (55.7% to 61.5%) of those who only picked up medication at the facility (p<0.001). Use of mHealth for at least one but less than half of the visits had the highest level of adherence at 84.6% (82.4% to 86.9%) compared with 49.6% (46.1% to 53.0%) among those who did not use mHealth and 67.2% (62.5% to 72.0%) for those who used mHealth at least half their visits (p<0.001). CONCLUSIONS: Adherence to fluoxetine was high relative to existing selective serotonin reuptake inhibitors adherence data, the majority of which is from high-income countries. Adherence was higher during the first half of treatment. People who were older, living with HIV and opted to use community delivery of medication and/or mHealth had higher adherence. TRIAL REGISTRATION NUMBER: NCT03466346.