Mortality along the continuum of HIV care in Rwanda: a model-based analysis

Development and calibration of a mathematical model of HIV outcomes among Rwandan adults: informing equitable achievement of targets in Rwanda

Background

We developed and calibrated the Central Africa-International epidemiology Databases to Evaluate AIDS (CA-IeDEA) HIV policy model to inform equitable achievement of global goals, overall and across sub-populations, in Rwanda.

Methods

We created a deterministic dynamic model to project adult HIV epidemic and care continuum outcomes, overall and for 25 subpopulations (age group, sex, HIV acquisition risk, urbanicity). Data came from the Rwanda cohort of CA-IeDEA, 2004-2020; Rwanda Demographic and Health Surveys, 2005, 2010, 2015; Rwanda Population-based HIV Impact Assessment, 2019; and the literature and reports. We calibrated the model to 47 targets by selecting the 50 best-fitting parameter sets among 20,000 simulations. Calibration targets reflected epidemic (HIV prevalence, incidence), global goals (percentage on antiretroviral therapy (ART) among diagnosed, percentage virally suppressed among on ART) and other (number on ART, percentage virally suppressed) indicators, overall and by sex. Best-fitting sets minimized the summed absolute value of the percentage deviation (AVPD) between model projections and calibration targets. Good model performance was mean AVPD ≤5% across the 50 best-fitting sets and/or projections within the target confidence intervals; acceptable was mean AVPD >5% and ≤15%.

Results

Across indicators, 1,841 of 2,350 (78.3%) model projections were a good or acceptable fit to calibration targets. For HIV epidemic indicators, 256 of 300 (85.3%) projections were a good fit to targets, with the model performing better for women (83.3% a good fit) than for men (71.7% a good fit). For global goals indicators, 96 of 100 (96.0%) projections were a good fit; model performance was similar for women and men. For other indicators, 653 of 950 (68.7%) projections were a good or acceptable fit. Fit was better for women than for men (percentage virally suppressed only) and when restricting targets for number on ART to 2013 and beyond.

Conclusions

The CA-IeDEA HIV policy model fits historical data and can inform policy solutions for equitably achieving global goals to end the HIV epidemic in Rwanda. High-quality, unbiased population-based data, as well as novel approaches that account for calibration target quality, are critical to ongoing use of mathematical models for programmatic planning.

Patient-level outcomes and virologic suppression rates in HIV-infected patients receiving antiretroviral therapy in Rwanda

The Rwanda national HIV program has been successful at scaling up antiretroviral therapy (ART) to achieve universal access. The AIDSRelief Model of Care focuses on four key principles: (1) earlier initiation of ART; (2) use of durable, highly-potent, and sequence-friendly first-line ART regimens; (3) early detection of treatment failure; and (4) provision of community-based care and support to ensure optimal adherence and follow up/engagement in care. We conducted a retrospective cohort study of randomly-selected HIV-infected patients at AIDSRelief-supported sites using a stratified, random sample of 583 adults (>15 years) who initiated ART from 30 June 2008 to 1 February 2010. At ART initiation, the median patient age was 38 years, and 67% were female. The baseline median CD4+ cell count was 309 cells/mm³. Overall virologic suppression was 91%. Married/ever married status (adjusted prevalence odds ratio [aPOR] 3.75, 95% confidence interval [CI] 1.30-10.78) and self-reported adherence ≥95% in the past month (aPOR 2.76, 95% CI 1.00-7.62) were significantly associated with viral suppression in the multivariable model. Excellent virologic outcomes were achieved in Rwandan AIDSRelief sites utilizing the AIDSRelief Model of Care during the scale-up of ART in the country.