The Impact of Differentiated Service Delivery Models on 12-Month Retention in HIV Treatment in Mozambique: An Interrupted Time Series Analysis

Background: HIV treatment has been available in Mozambique since 2003, but coverage and retention in antiretroviral therapy (ART) remain suboptimal. To increase health system efficiency and reduce HIV-associated mortality, in November 2018 the Ministry of Health launched national guidelines on implementing eight differentiated service delivery models for HIV treatment. In this study, we assessed the impact of implementation on the proportion of clients retained in ART at 12-months in Mozambique, and explored the associated effects of COVID-19.Methods: Data were extracted from the Mozambique ART database, which contains client data from 51% of 1,455 health facilities providing ART in 2018. In an uncontrolled interrupted time series analysis, we compared 12-month retention in ART before (January 2017–November 2019) and after (December 2019–June 2021) implementation of the differentiated service delivery models–overall and by sex and age. We applied a generalized estimating equation model with a working independence assumption and cluster-robust standard errors to account for clustering at the facility level.Findings: The study included 613 facilities and 1,094,430 clients who started ART during the study period. Clients were 7% children, 20% adolescents and young adults, and 73% adults; 65% were female. Findings showed an increase of 24·5 (95% CI, 21·1 to 28·0) percentage points in retention at 12 months after implementation of the differentiated service delivery models. The smallest impact was observed in children (6·1%; 95% CI, 1·3% to 10·9%) and the largest in males (29·7%; 95% CI, 25·6% to 33·7%). Our analysis showed that COVID-19 had a negative effect on the impact of the service delivery models (-10·0%; 95% CI, -18·2% to -1·8).Interpretation: Implementation of eight differentiated service delivery models for HIV treatment had a positive and significant impact on the 12-month retention in ART. COVID-19 negatively influenced the impact of the models.Funding: This study was not funded. Declaration of Interest: None to declare. Ethical Approval: This work was approved by the Mozambique National Ethics Committee (634/CNBS/20) and the University of Washington Institutional Review Board (FWA#00006878). MISAU gave administrative approval to use client data (1984/GMS/002/2020).