Service penetration, acceptability, appropriateness, and fidelity of a multicomponent navigation strategy for HIV-associated Kaposi's sarcoma: mixed methods evaluation

Kaposis sarcoma (KS) remains common in sub-Saharan Africa and despite persistently high mortality less than 50% of people with advanced-stage KS with an indication for chemotherapy currently receive it in western Kenya. To address this, a tailored multi-component navigation strategy including physical navigation and care coordination, peer mentorship, education, assistance with health insurance, a health insurance stipend, and transportation stipends was implemented within AMPATH healthcare network in western Kenya in 2021. This study evaluates service penetration (engagement), acceptability, appropriateness, and fidelity to the multi-component navigation strategy. We used a convergent mixed methods approach using Proctor et al.s framework for implementation outcomes. We enrolled all adults with newly diagnosed HIV-associated KS from 2021 to 2024. Quantitative data included structured questionnaires, CD4+ T cell count, and navigation activity logs. Scores for acceptability and appropriateness questionnaires ranged from 4 to 20, with 20 representing high levels. In-depth interviews were also conducted among people with HIV-associated KS, healthcare workers, and navigation team members. Descriptive statistics were used for measures of service penetration (engagement), acceptability, appropriateness, and fidelity. Framework analysis was used for in-depth interviews. Among the 124 Adults with HIV associated KS eligible to participate, service penetration was 74% within 90 days after KS diagnosis. The median acceptability score among people with HIV-associated KS was 20 (Range: 19, 20) and appropriateness was 20 (Range 20, 20). Fidelity to at least one component was 87% (N=80), and no participant experienced all 6 components. Fidelity was 2.2% (N=2) for the transportation stipends (7 total) and 28% (N=26) for the health insurance enrollment stipend. During in-depth interviews, patients and healthcare workers described high levels of acceptability and appropriateness of the navigation strategy. Patients described experiences of variability in navigation strategy components, and healthcare worker and navigation team members described how financial constraints and time constraints contributed to variability in fidelity. A multi-component navigation strategy designed to improve chemotherapy engagement for HIV-associated KS was both acceptable and appropriate. Fidelity was variable with low fidelity to financial components, suggesting areas for future adaptation to ensure sustainability and context appropriateness during integration into the health system and future scale-up.