Community-based management of arterial hypertension and cardiovascular risk factors by lay village health workers for people with controlled and uncontrolled blood pressure in rural Lesotho: joint protocol for two cluster-randomized trials within the ComBaCaL cohort study (ComBaCaL aHT Twic 1 and ComBaCaL aHT TwiC 2)
Authors: Gerber Felix , Gupta Ravi , Lejone Thabo Ishmael , Tahirsylaj Thesar , Lee Tristan , Sanchez-Samaniego Giuliana , Kohler Maurus , Haldemann Maria-Inés , Raeber Fabian , Chitja Mamakhala , Mathulise Malebona , Kabi Thuso , Mokaeane Mosoetsi , Maphenchane Malehloa , Molulela Manthabiseng , Khomolishoele Makhebe , Mota Mota , Masike Sesale , Bane Matumaole , Sematle Mamoronts’ane Pauline , Makabateng Retselisitsoe , Mphunyane Madavida , Phaaroe Sejojo , Basler Dave Brian , Kindler Kevin , Burkard Thilo , Briel Matthias , Chammartin Frédérique , Labhardt Niklaus Daniel , Amstutz Alain 
Published: June 2024

Abstract
Background
Arterial hypertension (aHT) is a major cause for premature morbidity and mortality. Control rates remain poor, especially in low- and middle-income countries. Task-shifting to lay village health workers (VHWs) and the use of digital clinical decision support systems may help to overcome the current aHT care cascade gaps. However, evidence on the effectiveness of comprehensive VHW-led aHT care models, in which VHWs provide antihypertensive drug treatment and manage cardiovascular risk factors is scarce.

Methods
Using the trials within the cohort (TwiCs) design, we are assessing the effectiveness of VHW-led aHT and cardiovascular risk management in two 1:1 cluster-randomized trials nested within the Community-Based chronic disease Care Lesotho (ComBaCaL) cohort study (NCT05596773). The ComBaCaL cohort study is maintained by trained VHWs and includes the consenting inhabitants of 103 randomly selected villages in rural Lesotho. After community-based aHT screening, adult, non-pregnant ComBaCaL cohort participants with uncontrolled aHT (blood pressure (BP) ≥ 140/90 mmHg) are enrolled in the aHT TwiC 1 and those with controlled aHT (BP < 140/90 mmHg) in the aHT TwiC 2. In intervention villages, VHWs offer lifestyle counseling, basic guideline-directed antihypertensive, lipid-lowering, and antiplatelet treatment supported by a tablet-based decision support application 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 (< 140/90 mmHg) 12 months after enrolment. We hypothesize that the intervention is superior regarding BP control rates in participants with uncontrolled BP (aHT TwiC 1) and non-inferior in participants with controlled BP at baseline (aHT TwiC 2).

Discussion
The TwiCs were launched on September 08, 2023. On May 20, 2024, 697 and 750 participants were enrolled in TwiC 1 and TwiC 2. To our knowledge, these TwiCs are the first trials to assess task-shifting of aHT care to VHWs at the community level, including the prescription of basic antihypertensive, lipid-lowering, and antiplatelet medication in Africa. The ComBaCaL cohort and nested TwiCs are operating within the routine VHW program and countries with similar community health worker programs may benefit from the findings.

Trial registration
ClinicalTrials.gov NCT05684055. Registered on January 04, 2023.