Implementation strategies to improve HIV care cascade outcomes in low- and middle-income countries: a systematic review from 2014 to 2021

IntroductionIn low- and middle-income countries (LMICs), which are disproportionately affected by the HIV epidemic and manage limited resources, optimized implementation strategies are needed to enhance the efficiency of the HIV response. Assessing strategy usage to date could identify research gaps and inform future implementation efforts. We conducted a systematic review to describe the features and distributions of published implementation strategies attempting to improve HIV treatment service delivery and outcomes.MethodsWe searched PubMed, Embase, and CINAHL and screened abstracts and full texts published between 1 January 2014 and 27 August 2021, for English-language studies conducted in LMICs that described the implementation of HIV intervention and reported at least one HIV care cascade outcome, ranging from HIV testing to viral suppression. Implementation strategies were inductively specified, characterized by unique combinations of actor, action and action target, and summarized based on existing implementation strategy taxonomies. All strategies included in this study were independently reviewed to ensure accuracy and consistency.ResultsWe identified 44,126 abstracts and reviewed 1504 full-text manuscripts. Among 485 included studies, 83% were conducted in sub-Saharan Africa; the rest were conducted in South-East Asia and Western Pacific (12%), and the Americas (8%). A total of 7253 unique implementation strategies were identified, including changing health service delivery (48%) and providing capacity building and support strategies (34%). Healthcare providers and researchers led 59% and 28% of the strategies, respectively. People living with HIV and their communities (62%) and healthcare providers (38%) were common strategy targets. Strategies attempting to change governance, financial arrangements and implementation processes were rarely reported.DiscussionWe identified a range of published implementation strategies that addressed HIV cascade outcomes, though some key gaps exist. We may need to expand the application of implementation strategies to ensure that all stakeholders are meaningfully involved to support equitable implementation efforts across the geographic regions and target populations, and to optimize implementation outcomes.ConclusionsSome health service delivery and capacity building and support strategies have been most commonly used to date. Future research and implementation may incorporate a more diverse range of strategies and detailed reporting on their usage to inform improved HIV responses globally.