Jacqueline Chinkonde, Chileshe Chilangwa, Nicole B Carbone, Stephanie M. Topp, Michael Eliya, Benjamin H. Chi, Maganizo Chagomerana, Sam Phiri, Lauren C Zalla, Jessie K. Edwards, Emily B Wroe, Michael E Herce, Innocent Mofolo, Mina C. Hosseinipour, and Maria H. Kim
Background In sub-Saharan Africa, 3 community-facility linkage (CFL) models—Expert Clients, Community Health Workers (CHWs), and Mentor Mothers—have been widely implemented to support pregnant and breastfeeding women (PBFW) living with HIV and their infants to access and sustain care for prevention of mother-to-child transmission of HIV (PMTCT), yet their comparative impact under real-world conditions is poorly understood. Methods and findings We sought to estimate the effects of CFL models on a primary outcome of maternal loss to follow-up (LTFU), and secondary outcomes of maternal longitudinal viral suppression and infant “poor outcome” (encompassing documented HIV-positive test result, LTFU, or death), in Malawi’s PMTCT/ART program. We sampled 30 of 42 high-volume health facilities (“sites”) in 5 Malawi districts for study inclusion. At each site, we reviewed medical records for all newly HIV-diagnosed PBFW entering the PMTCT program between July 1, 2016 and June 30, 2017, and, for pregnancies resulting in live births, their HIV-exposed infants, yielding 2,589 potentially eligible mother–infant pairs. Of these, 2,049 (79.1%) had an available HIV treatment record and formed the study cohort. A randomly selected subset of 817 (40.0%) cohort members underwent a field survey, consisting of a questionnaire and HIV biomarker assessment. Survey responses and biomarker results were used to impute CFL model exposure, maternal viral load, and early infant diagnosis (EID) outcomes for those missing these measures to enrich data in the larger cohort. We applied sampling weights in all statistical analyses to account for the differing proportions of facilities sampled by district. Of the 2,049 mother–infant pairs analyzed, 62.2% enrolled in PMTCT at a primary health center, at which time 43.7% of PBFW were ≤24 years old, and 778 (38.0%) received the Expert Client model, 640 (31.2%) the CHW model, 345 (16.8%) the Mentor Mother model, 192 (9.4%) ≥2 models, and 94 (4.6%) no model. Maternal LTFU varied by model, with LTFU being more likely among Mentor Mother model recipients (adjusted hazard ratio [aHR]: 1.45; 95% confidence interval [CI]: 1.14, 1.84; p = 0.003) than Expert Client recipients. Over 2 years from HIV diagnosis, PBFW supported by CHWs spent 14.3% (95% CI: 2.6%, 26.1%; p = 0.02) more days in an optimal state of antiretroviral therapy (ART) retention with viral suppression than women supported by Expert Clients. Infants receiving the Mentor Mother model (aHR: 1.24, 95% CI: 1.01, 1.52; p = 0.04) and ≥2 models (aHR: 1.44, 95% CI: 1.20, 1.74; p < 0.001) were more likely to undergo EID testing by age 6 months than infants supported by Expert Clients. Infants receiving the CHW and Mentor Mother models were 1.15 (95% CI: 0.80, 1.67; p = 0.44) and 0.84 (95% CI: 0.50, 1.42; p = 0.51) times as likely, respectively, to experience a poor outcome by 1 year than those supported by Expert Clients, but not significantly so. Study limitations include possible residual confounding, which may lead to inaccurate conclusions about the impacts of CFL models, uncertain generalizability of findings to other settings, and missing infant medical record data that limited the precision of infant outcome measurement. Conclusions In this descriptive study, we observed widespread reach of CFL models in Malawi, with favorable maternal outcomes in the CHW model and greater infant EID testing uptake in the Mentor Mother model. Our findings point to important differences in maternal and infant HIV outcomes by CFL model along the PMTCT continuum and suggest future opportunities to identify key features of CFL models driving these outcome differences., Michael Herce and co-workers study potential improvements in linkage to care for prevention of mother to child transmission of HIV in Malawi., Author summary Why was this study done? Attrition from the prevention of mother-to-child transmission of HIV (PMTCT) continuum threatens health gains for pregnant and breastfeeding women (PBFW) living with HIV and their infants. To improve PMTCT services in Africa, 3 community-facility linkage (CFL) models—Mentor Mothers, Community Health Workers (CHWs), and Expert Clients/Patients—have been widely implemented. Available evidence suggests that these CFL models may improve the health of PBFW living with HIV and their infants. Despite the promise of CFL models, however, no studies from the current “treat all” era have attempted to examine which of these models works best in “real world” PMTCT programs for ensuring maternal HIV care retention and viral suppression and infant HIV-free survival. What did the researchers do and find? We conducted a descriptive study in Malawi by sampling busy health facilities in 5 districts and, at selected facilities, reviewing medical records for all newly HIV-diagnosed PBFW and their HIV-exposed infants. We then administered a survey to a randomly selected subset of these mother–infant pairs to assess CFL model exposure and HIV outcomes. We found that compared to women supported by the most common CFL model, Expert Clients, women supported by CHWs were 13% more likely to start antiretroviral therapy (ART) soon after their HIV diagnosis. Over the 2 years following HIV diagnosis, PBFW living with HIV who received CHW model support spent 14% more time retained on ART and virally suppressed than women in the Expert Client model. Infants receiving Mentor Mother model support were 24% more likely to receive HIV testing by age 6 months than infants supported by Expert Clients. The 12-month infant risk of experiencing a positive HIV test result, loss to follow-up, or death did not vary significantly by CFL model. What do these findings mean? CFL models had widespread coverage in the national PMTCT/ART program in our selected sites in Malawi, reaching most mother–infant pairs. Important differences were noted in maternal and infant HIV outcomes by CFL model. Favorable HIV outcomes were seen in women supported by the CHW model, and higher infant EID testing uptake was observed in infants supported by Mentor Mothers. Although caution should be exercised when applying our findings to other settings, we found that CFL models may have different impacts on maternal and infant HIV outcomes at different steps along the PMTCT continuum in Malawi. Future research should identify the key features of CFL models that drive these outcome differences to better inform PMTCT programming in Malawi.