Describing Engagement in the HIV Care Cascade: A Methodological Study

INTRODUCTION: Engagement in the HIV care cascade is required for people living with HIV (PLWH) to achieve an undetectable viral load. However, varying definitions of engagement exist, contributing to heterogeneity in research regarding how many individuals are actively participating and benefitting from care. A standardized definition is needed to enhance comparability and pooling of data from engagement studies. OBJECTIVES: The objective of this paper was to describe the various definitions for engagement used in HIV clinical trials. METHODS: Articles were retrieved from CASCADE, a database of 298 clinical trials conducted to improve the HIV care cascade (https://hivcarecascade.com/), curated by income level, vulnerable population, who delivered the intervention, the setting in which it was delivered, the intervention type, and the level of pragmatism of the intervention. Studies with engagement listed as an outcome were selected from this database. RESULTS: 13 studies were eligible, of which five did not provide an explicit definition for engagement. The remaining studies used one or more of the following: appointment adherence (n=6), laboratory testing (n=2), adherence to antiretroviral therapy (n=2), time specification (n=5), intervention adherence (n=5), and quality of interaction (n=1). CONCLUSION: This paper highlights the existing diversity in definitions for engagement in the HIV care cascade and categorize these definitions into appointment adherence, laboratory testing, adherence to antiretroviral therapy, time specification, intervention adherence, and quality of interaction. We recommend consensus on how to describe and measure engagement.