Cohort profile: design, sociodemographic characteristics, chronic disease risk factors, and baseline hypertension and diabetes care cascades of the open, prospective Community-Based chronic disease Care Lesotho (ComBaCaL) cohort
Authors: Gerber Felix , Sanchez-Samaniego Giuliana , Tahirsylaj Thesar , Lejone Thabo Ishmael , Lee Tristan , 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 , Gupta Ravi , Ayakaka Irene , Mphunyane Madavida , Sao Lebohang , Tlahali Mosa , Phaaroe Sejojo , Litaba Malitaba , Basler Dave Brian , Kindler Kevin , Grimm Pauline , Seelig Eleonora , Burkard Thilo , Briel Matthias , Chammartin Frédérique , Amstutz Alain , Labhardt Niklaus Daniel 
Published: September 2024

Purpose

The open, prospective Community-Based chronic Care Lesotho (ComBaCaL) cohort is the first study to comprehensively investigate socioeconomic indicators, common chronic diseases and their risk factors in a remote rural setting in Lesotho. It serves as a platform for implementing nested trials using the Trials within Cohorts (TwiCs) design to assess community-based chronic care interventions. Here, we present the cohort’s sociodemographic and chronic disease risk factor profile, including self-reported HIV prevalence and hypertension and diabetes care cascades.

Participants

Since February 2023, Community Health Worker (CHWs) supported by a clinical decision support and data collection application, have enrolled inhabitants from 103 randomly selected rural villages in Butha-Buthe and Mokhotlong districts in North-East Lesotho. As of May 31, 2024, the cohort includes 5’008 households with 14’735 participants (55% female, median age 19 years). The cohort’s socioeconomic status is low with an International Wealth Index of 26, a monthly household income of 42.4 USD and low levels of formal education. Among the 7’917 adult participants, 42.5% are overweight or obese, with higher rates among women, and 33.1% smoke tobacco, with higher rates among men. Self-reported HIV prevalence is 15.1% with a 98.4% treatment rate. Hypertension prevalence is 17% with a 56% control rate and diabetes prevalence is 4% with a 39% control rate.

Findings to date

The cohort’s low socioeconomic status is linked to multiple health risks including insufficient access to clean energy, essential healthcare services, adequate sanitary facilities and secure food supply. Besides the expected high HIV prevalence, we found significant hypertension, diabetes and cardiovascular risk factor prevalences. While treatment and control rates for diabetes and hypertension are higher than in similar settings, they remain below global targets.

Future plans

Ongoing cluster-randomized TwiCs, which will be completed in 2025, are assessing the effectiveness of community-based, CHW-led care interventions for diabetes and hypertension. CHWs will continue to closely monitor the cohort and integrate additional measurements such as HIV testing. This will provide further insights into the dynamics and interactions of chronic diseases and inform the development of future nested trials on innovative community-based prevention and care interventions.

Registration

NCT05596773

Strengths and limitations

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Comprehensive Data Collection: The ComBaCaL cohort offers comprehensive data on sociodemographics, chronic disease risk factors, and hypertension and diabetes care cascades within a large, representative sample of the rural population in Lesotho.

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Community-Based Approach: Data is captured by local Community Health Workers residing in the study villages using a tailored clinical decision support and data collection application. This approach allows for continuous data collection, remote monitoring by study staff, and data verification, ensuring nearly complete village enrolment and high data quality.

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Efficient study design: The cohort utilizes the Trials within Cohorts (TwiCs) design, which allows for the efficient implementation of multiple randomized nested trials to assess the effectiveness of innovative health interventions.

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Reliance on self-reported data: Assessments other than hypertension and diabetes screening outcomes rely on self-reported data, which may have limited correlation with objective assessments.

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Limitations in data scope: Clinical data on chronic conditions other than hypertension and diabetes remain limited and anthropometric and behavioural risk factor data for children has not yet been collected.