Research

The ComBaCaL project aims at developing and assessing sustainable chronic care delivery models based on the latest scientific evidence and extensive community input to enhance access to essential health services in rural Lesotho. The ComBaCaL model of care combines the decentralization of essential chronic disease services through the involvement of Village Health Workers (VHWs) and the use of innovative digital health solutions.

ComBaCaL conducts its research activities in the districts of Butha-Buthe and Mokhotlong, Lesotho. In 2021, a disease prevalence survey involving over 6,000 participants was conducted. In 2022, the ComBaCaL pilot cohort was established in 10 villages, aimed at preparing for a larger main cohort and serving as a platform to test innovative VHW-led service delivery strategies. In 2023, the ComBaCaL main cohort was established in 103 rural villages with the objectives of assessing the evolving chronic disease burden and evaluating the effectiveness and implementation of VHW-led health service delivery strategies.

The ComBaCaL Main Cohort

The ComBaCaL main cohort consists of more than 14,000 consenting inhabitants of 103 randomly selected rural villages in the districts of Butha-Buthe and Mokhotlong, Lesotho. In each cohort village, one VHW equipped with a tablet loaded with a tailored clinical decision support and data collection application (ComBaCaL app) prospectively collects data on chronic disease risk factors and complications. The ComBaCaL main cohort uses the Trial within Cohorts (TwiCs) design that allows for the efficient implementation of multiple randomized trials within the cohort.

Baseline characteristics of the cohort are currently available as a preprint. Overall, the cohort consists of a population with low socioeconomic status, limited levels of formal education and insufficient access to clean toilets, energy, and water, posing multiple health risks. Significant prevalences of arterial hypertension (aHT), type 2 diabetes mellitus (T2D), and HIV were observed.

Currently, three TwiCs are evaluating the effectiveness of community-based aHT and T2D care delivered by VHWs.

aHT TwiCs

We are assessing the effectiveness of VHW-led aHT and cardiovascular risk management in two 1:1 cluster-randomized trials (protocol). Participants with uncontrolled aHT are enrolled in the aHT TwiCs 1 and those with controlled aHT in the aHT TwiCs 2.

In intervention villages, VHWs supported by a tablet-based clinical decision support system (CDSS) offer lifestyle counselling, basic guideline-directed antihypertensive, lipid-lowering, and antiplatelet treatment to eligible participants. In control villages, participants are referred to a health facility for therapeutic management.

The primary endpoint for both TwiCs is the proportion of participants with controlled BP levels 12 months after enrolment. We hypothesize that the intervention is superior regarding BP control rates in participants with uncontrolled BP (aHT TwiCs 1) and non-inferior in participants with controlled BP at baseline (aHT TwiCs 2).

1,352 participants with aHT are enrolled in the two TwiCs. Recruitment was completed in May 2024 and results are expected one year thereafter.

T2D TwiCs

We are also evaluating the effectiveness of a VHW-led, CDSS-assisted care model among non-pregnant adults with T2D (protocol). In intervention villages, VHWs offer a community-based T2D care package including lifestyle counselling, first-line oral antidiabetic, lipid-lowering, and antiplatelet treatment guided by a tablet-based CDSS as well as treatment support to participants who prefer or clinically require facility-based T2D care.

In control clusters, all participants will be referred to a health facility for T2D management. The primary endpoint is the mean glycosylated haemoglobin (HbA1c) 12 months after enrolment. Secondary endpoints include the 10-year risk for cardiovascular events estimated using the World Health Organization risk prediction tool.

Our hypothesis is that offering community-based, VHW-led, CDSS-assisted T2D care is superior regarding HbA1c levels 12 months after enrollment compared to offering facility-based T2D care among non-pregnant adults with uncomplicated and uncontrolled T2D.

253 participants with T2D are enrolled in the TwiCs. Recruitment was stopped in January 2024 and results expected one year thereafter.

HIV Prevention and Care TwiCs

A TwiCs planned for 2025 will evaluate the effectiveness and implementation of a VHW-led, CDSS-assisted HIV prevention and care service delivery model. In selected intervention villages, VHWs will conduct community-based HIV testing and deliver a comprehensive HIV prevention and care package. This package will target individuals at high risk of acquiring HIV and offer a variety of biomedical HIV prevention options. VHWs will also manage antiretroviral refills, provide adherence support, and initiate treatment for eligible individuals living with HIV. Additionally, all services will be integrated into a broader sexual and reproductive health service package to ensure comprehensive care.

In contrast, control villages will have VHWs conducting community-based HIV testing and providing education on HIV prevention and care. Individuals at substantial risk of acquiring HIV will be referred to health facilities for biomedical prevention services. People living with HIV will receive adherence support from VHWs but will be directed to health facilities for additional services.

We hypothesize that this integrated, community-based, VHW-led, CDSS-assisted model will be more effective in reducing population-level person-time spent with elevated viremia, serving as a proxy for HIV incidence, over a 24-month follow-up period.

The ComBaCaL Pilot Cohort

aHT and T2D Pilot TwiCs

Two pilot TwiCs assessed the feasibility, acceptability and potential effectiveness of VHW-led management of aHT and T2D. The pilot TwiCs also sought to ascertain whether VHWs are able to cope with the additional workload with minimal supervision. Based on the learnings and preliminary data from these pilot studies, the service delivery models were refined for evaluation in the TwiCs in the main cohort.

Digital Health

The pilot cohort was the first group to become trained on the CDSS too (the ComBaCaL app) that was developed to enable VHWs to deliver healthcare services that are traditionally provided by healthcare professionals, such as the prescription of basic antidiabetic and antihypertensive treatment. The ComBaCaL app is based on the open-source Community Health Toolkit that enables the implementation of flexible workflows for community-based healthcare delivery offering essential features such as offline-first functionalities, automated task triggering and real-time remote monitoring. First experiences of using the ComBaCaL app in our pilot cohort showed that it is perceived as useful and appropriate by the VHWs and empowers them in their daily work in the communities. Based on the experiences of using the ComBaCaL app in the pilot cohort, it was further refined to its current version used in the main cohort.

HIV Prevention Pilot Study

A single-arm pre-post pilot study will assess the feasibility of a community-based, CDSS-assisted, VHW-led, integrated dynamic HIV prevention choice model while also examining the patterns of changes in HIV risk behaviour and prevention use over time. VHWs will offer community-based HIV testing and offer comprehensive HIV prevention packages, including a choice of biomedical HIV prevention, to participants at substantial risk of HIV acquisition. Participants will be able to initiate and switch between biomedical prevention products (oral TDF-based Pre-Exposure Prophylaxis, Dapivirine Vaginal Ring, Dual Prevention Pill, and Post-Exposure Prophylaxis) according to their needs and preferences.

The ComBaCaL pilot cohort includes over 1,800 consenting participants from 10 villages and informed the design and implementation of the ComBaCaL main cohort. Within this cohort, two pilot TwiCs assessed the feasibility, acceptability, and potential effectiveness of VHW-led aHT and T2D management. These TwiCs also evaluated experiences with eHealth tools used in the interventions. Additionally, another nested study will pilot a VHW-led HIV prevention initiative.

We conducted a large population-based household survey on non-communicable chronic diseases in two districts in northeastern Lesotho.

NCD Prevalence Survey

Results showed that of the 6,108 participants with blood pressure readings and 5,698 with random blood glucose tests, 631 had elevated blood pressure (≥ 140/90 mmHg) and 80 had DM with HbA1c ≥ 6.5%. 61 participants had both conditions while 4,457 had neither condition.

The survey also measured the prevalence of target end organ damage, implemented focused echocardiography with AI-supported analysis, and evaluated of the accuracy of unattended blood pressure measurement.