Evaluating the efficiency of community-based HIV testing and counseling strategies in sub-Saharan Africa
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Knowledge of one’s HIV status is vital to accessing treatment and prevention yet only a fraction of individuals in sub-Saharan Africa are regularly tested for HIV. Community-based HIV testing and counseling (HTC), defined as HTC conducted outside of a healthcare facility, has the potential to achieve high population testing coverage and linkage to care. The studies within this dissertation describe effectiveness and efficiency (cost-effectiveness) of various modalities of community-based HTC. Aim 1 presents a systematic review of community and facility-based HTC strategies in sub-Saharan Africa. Aims 2 and 3 evaluate the cost-effectiveness of two types of community HTC interventions in western Kenya by incorporating primary cost and effectiveness data from randomized clinical trials into an HIV mathematical model. Specifically, Aim 2 assesses the health and economic impact of implementing a home-based partner education and HIV testing (HOPE) intervention for pregnant women and their male partners. Aim 3 evaluates the cost-effectiveness of scaling up provider notification services for sexual partners of recently diagnosed HIV-positive persons. In Aim 1, we found that community HTC (including home, mobile, partner notification, key populations, campaign, workplace and self-testing) successfully reached target groups (men, young adults and first-time testers) with higher coverage than facility HTC. Community HTC also identifies HIV-positive individuals at higher CD4 counts who were likely to be earlier in their disease course. Combined with the potential of community HTC with facilitated linkage to achieve high linkage to treatment with similar retention rates as facility HTC, this suggests that scaling up community interventions can reduce the morbidity, mortality and transmission associated with late or non-initiation of ART. Of all modalities examined, home HTC attained the highest population coverage (70%, 95% CI = 58–79) while mobile HTC reached the highest proportion of men (50%, 95% CI = 47–54%). Self-testing reached the highest proportion of young adults (66%, 95% CI = 65–67%). As each HTC modality reaches distinct sub-populations, a combination of modalities (differing by setting) will likely be needed to achieve high ART coverage. In Aim 2, we found that the incremental cost of adding the HOPE intervention to standard antenatal care was $31-37 USD per couple tested; task shifting intervention responsibilities to community health workers lowered the cost to $14-16 USD per couple tested. At 60% coverage of male partners, HOPE was projected to avert 6,987 HIV infections and 2,603 deaths in Nyanza province over 10 years with an incremental cost-effectiveness ratio (ICER) of $886 and $615 per DALY averted for the program and task-shifting scenario, respectively. The ICERs are below the threshold of Kenya’s per capita gross domestic product ($1,358) and are therefore considered cost-effective. We conclude that the HOPE intervention can cost-effectively decrease HIV-associated morbidity and mortality in western Kenya by linking HIV-positive male partners to care. In Aim 3, we found that implementing assisted partner services (aPS) or active tracing, exposure notification, and home HTC for sexual partners of newly diagnosed HIV-positive persons in western Kenya is projected to achieve 12% population coverage and reduce HIV infections by by 2.8% and HIV-related deaths by 1.5%. The incremental cost-effectiveness ratio (ICER) of implementing aPS is $1,703 USD (range $1,198-2,887) per disability-adjusted life year (DALY) averted. Task-shifting intervention activities from healthcare professionals to community health workers decreases the ICER to $1,302 (range $955-2,789) per DALY averted. The task-shifting scenario falls below Kenya’s per capita gross domestic product (GDP) and is therefore considered very cost-effective while the full program cost scenario is considered cost-effective under the higher threshold of 3-times Kenya’s per capita GDP. Intervention cost-effectiveness and HIV-related deaths averted among aPS partners increased with expanded ART initiation criteria. We hope that this dissertation work will be useful in forming policy deliberations regarding implementation of community HTC in countries of sub-Saharan Africa.
- Epidemiology