Hypertension care cascade at a large urban HIV clinic in Uganda: a mixed methods study using the Capability, Opportunity, Motivation for Behavior change (COM-B) model

Background: Persons living with HIV (PLHIV) receiving antiretroviral therapy (ART) have a high prevalence of hypertension (HTN) and increased risk of mortality from cardiovascular diseases. HTN and HIV care integration is recommended in Uganda, though its implementation has lagged. In this study, we sought to analyze the HTN and HIV care cascades and explore barriers and facilitators of HTN/HIV integration within a large HIV clinic in urban Uganda.

Methods: We conducted an explanatory sequential mixed methods study at Mulago ISS clinic in Kampala, Uganda. We determined proportions of patients in HTN and HIV care cascade steps of screened, diagnosed, initiated on treatment, retained, and controlled. Guided by the Capability, Opportunity, Motivation and Behavior (COM-B) model, we then conducted semi-structured interviews and focus group discussions with healthcare providers (n = 13) and hypertensive PLHIV (n = 32). We coded the qualitative data deductively and analyzed the data thematically categorizing them as themes that influenced HTN care positively or negatively. These denoted barriers and facilitators, respectively.

Results: Of 15,953 adult PLHIV, 99.1% were initiated on ART, 89.5% were retained in care, and 98.0% achieved control (viral suppression) at 1 year. All 15,953 (100%) participants were screened for HTN, of whom 24.3% had HTN. HTN treatment initiation, 1-year retention, and control were low at 1.0%, 15.4%, and 5.0%, respectively. Barriers and facilitators of HTN/HIV integration appeared in all three COM-B domains. Barriers included low patient knowledge of HTN complications, less priority by patients for HTN treatment compared to ART, sub-optimal provider knowledge of HTN treatment, lack of HTN treatment protocols, inadequate supply of anti-hypertensive medicines, and lack of HTN care performance targets. Facilitators included patients' and providers' interest in HTN/HIV integration, patients' interest in PLHIV peer support, providers' knowledge and skills for HTN screening, optimal ART adherence counseling, and availability of automated BP machines.

Conclusion: The prevalence of HTN among PLHIV is high, but the HTN care cascade is sub-optimal in this successful HIV clinic. To close these gaps, models of integrated HTN/HIV care are urgently needed. These findings provide a basis for designing contextually appropriate interventions for HTN/HIV integration in Uganda and other low- and middle-income countries.