Integrating HIV services and other health services: A systematic review and meta-analysis

Abstract

Background: Integration of HIV services with other health services has been proposed as an important strategy to boost the sustainability of the global HIV response. We conducted a systematic and comprehensive synthesis of the existing scientific evidence on the impact of service integration on the HIV care cascade, health outcomes, and cost-effectiveness.

Methods and findings: We reviewed the global quantitative empirical evidence on integration published between 1 January 2010 and 10 September 2021. We included experimental and observational studies that featured both an integration intervention and a comparator in our review. Of the 7,118 unique peer-reviewed English-language studies that our search algorithm identified, 114 met all of our selection criteria for data extraction. Most of the studies (90) were conducted in sub-Saharan Africa, primarily in East Africa (55) and Southern Africa (24). The most common forms of integration were (i) HIV testing and counselling added to non-HIV services and (ii) non-HIV services added to antiretroviral therapy (ART). The most commonly integrated non-HIV services were maternal and child healthcare, tuberculosis testing and treatment, primary healthcare, family planning, and sexual and reproductive health services. Values for HIV care cascade outcomes tended to be better in integrated services: uptake of HIV testing and counselling (pooled risk ratio [RR] across 37 studies: 1.67 [95% CI 1.41-1.99], p < 0.001), ART initiation coverage (pooled RR across 19 studies: 1.42 [95% CI 1.16-1.75], p = 0.002), time until ART initiation (pooled RR across 5 studies: 0.45 [95% CI 0.20-1.00], p = 0.050), retention in HIV care (pooled RR across 19 studies: 1.68 [95% CI 1.05-2.69], p = 0.031), and viral suppression (pooled RR across 9 studies: 1.19 [95% CI 1.03-1.37], p = 0.025). Also, treatment success for non-HIV-related diseases and conditions and the uptake of non-HIV services were commonly higher in integrated services. We did not find any significant differences for the following outcomes in our meta-analyses: HIV testing yield, ART adherence, HIV-free survival among infants, and HIV and non-HIV mortality. We could not conduct meta-analyses for several outcomes (HIV infections averted, costs, and cost-effectiveness), because our systematic review did not identify sufficient poolable studies. Study limitations included possible publication bias of studies with significant or favourable findings and comparatively weak evidence from some world regions and on integration of services for key populations in the HIV response.

Conclusions: Integration of HIV services and other health services tends to improve health and health systems outcomes. Despite some scientific limitations, the global evidence shows that service integration can be a valuable strategy to boost the sustainability of the HIV response and contribute to the goal of 'ending AIDS by 2030', while simultaneously supporting progress towards universal health coverage.

Fig 1. Geographical map of the included empirical studies by type of integration.

Bubble colours represent the health service integration area. Bubble sizes represent the study population size. Coordinates are dispersed up to 250 kilometres to prevent overlap of data points from similar or nearby locations. Abbreviations: HPV, human papillomavirus; STI, sexually transmitted infection. Map created using ArcGIS software by ESRI. Base map source: https://www.naturalearthdata.com/downloads/10m-cultural-vectors/10m-admin-0-countries/.

Fig 2. Results of integration of HIV services: Uptake of HIV testing and counselling and yield of people testing HIV-positive.

(A) Uptake of HIV testing and counselling. (B) Yield of people testing HIV-positive. Outcomes are related to the ‘first 95’ of the 95-95-95 target for the HIV cascade of care. Each estimate indicates the size of the relationship between integration exposure and outcome. We measured these relationships as RRs; asterisks indicate statistically significant results. The diamond at the bottom of each panel shows the overall random-effects meta-analytical estimate. Abbreviations: CI, confidence interval; FSWs, female sex workers; MSM, men who have sex with men; PLHIV, people living with HIV; PWID, people who inject drugs; RR, risk ratio.

Fig 3. Results of integration of HIV services: ART initiation and time until ART initiation.

(A) ART initiation. (B) Time until ART initiation. Outcomes are related to the ‘second 95’ of the 95-95-95 HIV cascade of care. Each estimate indicates the size of the relationship between integration exposure and outcome. We measured these relationships as RRs; asterisks indicate statistically significant results. The diamond at the bottom of each panel shows the overall random-effects meta-analytical estimate. Abbreviations: ART, antiretroviral therapy; CI, confidence interval; DRC, Democratic Republic of the Congo; MSM, men who have sex with men; PLHIV, people living with HIV; PWID, people who inject drugs; RR, risk ratio.

Fig 4. Results of integration of HIV services for PLHIV: Retention in care, ART adherence, and viral suppression of those on ART.

(A) Retention in care. (B) ART adherence. (C) Viral suppression of those on ART. Outcomes are related to the ‘third 95’ of the 95-95-95 targets for the HIV cascade of care. Each estimate indicates the size of the relationship between integration exposure and outcome. We measured these relationships as RRs; asterisks indicate statistically significant results. The diamond at the bottom of each panel shows the overall random-effects meta-analytical estimate. Abbreviations: ART, antiretroviral therapy; CI, confidence interval; FSWs, female sex workers; MSM, men who have sex with men; PLHIV, people living with HIV; PWID, people who inject drugs; RR, risk ratio; SSA, sub-Saharan Africa.

Fig 5. Results of HIV service integration: HIV-free survival among infants, HIV infections averted, and AIDS-related mortality.

(A) HIV-free survival among infants. (B) HIV infections averted. (C) AIDS-related mortality. Outcomes are related to the ‘getting to zero’ targets for HIV/AIDS. Each estimate in (A) and (C) indicates the effect size as derived from a single study, either directly or by recalculating reported outcomes. Each estimate indicates the size of the relationship between integration exposure and outcome. We measured these relationships as RRs; asterisks indicate statistically significant results. The diamond at the bottom of each panel shows the overall random-effects meta-analytical estimate. Infections averted (B) are shown in 100 person-years. Abbreviations: CI, confidence interval; PLHIV, people living with HIV; PWID, people who inject drugs; RR, risk ratio; SSA, sub-Saharan Africa.

Fig 6. Results of HIV service integration: Uptake of non-HIV health services.

Each estimate indicates the effect size as derived from a single study, either directly or through recalculating reported outcomes. Each estimate indicates the size of the relationship between integration exposure and outcome. We measured these relationships as RRs; asterisks indicate statistically significant results. The diamond at the bottom of each panel shows the overall random-effects meta-analytical estimate. Abbreviations: CI, confidence interval; FSWs, female sex workers; MSM, men who have sex with men; PLHIV, people living with HIV; PWID, people who inject drugs; RR, risk ratio.

Fig 7. Results of HIV service integration: Treatment success for non-HIV-related diseases and conditions and non-AIDS-related mortality.

(A) Treatment success for non-HIV related diseases and conditions. (B) Non-AIDS-related mortality. Each estimate indicates the size of the relationship between integration exposure and outcome. We measured these relationships as RRs; asterisks indicate statistically significant results. The diamond at the bottom of each panel shows the overall random-effects meta-analytical estimate. CI, confidence interval; DRC, Democratic Republic of the Congo; MSM, men who have sex with men; PLHIV, people living with HIV; PWID, people who inject drugs; HPV, human papillomavirus; RR, risk ratio; SSA, sub-Saharan Africa.

Fig 8. Results of integration of HIV services and economic outcomes: Costs and cost-effectiveness.

(A–D) Costs of (A) HIV services only, (B) non-HIV services only, (C) HIV and non-HIV services combined, and (D) integrated non-HIV and HIV services compared to HIV services only. (E) Cost-effectiveness as ICERs. Each cost estimate indicates the effect size derived from a single study, either directly or through recalculating reported outcomes. The estimates represent the costs of services in integrated compared to separate services. The ICERs measure the cost-effectiveness of integration, compared to the cost-effectiveness of stand-alone HIV service delivery as reported in the studies. Abbreviations: ART, antiretroviral therapy; DALY, disability-adjusted life year; HPV, human papillomavirus; ICER, incremental cost-effectiveness ratio; MSM, men who have sex with men; PLHIV, people living with HIV; PWID, people who inject drugs; QALY, quality-adjusted life year; STI, sexually transmitted infection.