Home / Central Data Catalog / AHRI.IMPACTBP
central

Implementation Evaluation of a Combination Intervention for Sustainable Blood Pressure Control in Rural KwaZulu-Natal, South Africa

South Africa, 2022 - 2025
Get Microdata
Reference ID
AHRI.ImpactBP
Producer(s)
Mark J. Siedner, Nombulelo Magula, Thomas Gaziano
Metadata
Documentation in PDF DDI/XML JSON
Created on
Feb 05, 2026
Last modified
Feb 06, 2026
Page views
91
Downloads
3
  • Identification
  • Version
  • Scope
  • Coverage
  • Producers and sponsors
  • Sampling
  • Data collection
  • Data processing
  • Data Access
  • Metadata production

    • Identification

    Survey ID number

    AHRI.ImpactBP
    Title

    Implementation Evaluation of a Combination Intervention for Sustainable Blood Pressure Control in Rural KwaZulu-Natal, South Africa
    Country
    Name Country code
    South Africa ZA
    Abstract

    IMPACT-BP was an open-label, randomised controlled trial to evaluate the effectiveness of community-based, technology-supported interventions to reduce systolic blood pressure (SBP) and improve blood pressure control among individuals with uncontrolled hypertension in rural KwaZulu-Natal.
    The study aimed to determine whether home-based care improves outcomes over standard, clinic-based blood pressure management in rural South Africa.

    The study compared three treatment strategies: 1) standard of care (SOC), clinic-based management of hypertension, 2) a community blood pressure monitor-based model, in which individuals received blood pressure cuffs to measure their blood pressure at home, and were monitored by nurses via community health workers (CHW) with treatment decisions made via nurses remotely via a mobile health-based clinical decision support tool, and 3) an enhanced community blood pressure monitor-based model that included home-based blood pressure cuffs that transmitted readings over cellular networks directly to clinic-based nurses (eCHW+). In both intervention groups, CHWs visited participants to record (CHW) or verify (eCHW+) blood pressure readings, dispense medications, and relay instructions from clinic nurses.
    Kind of Data

    Survey Data, clinical data, biomarker data, administrative records data, spatial data
    Unit of Analysis

    Individual-level longitudinal clinical trial data. Each record represents a single participant enrolled in the hypertension trial, with repeated measures of blood pressure, clinical assessments, medication use, and survey-based sociodemographic information collected across multiple study visits (enrolment, 6 months, and 12 months). Data are linked at the individual level using unique study identifiers.

    Version

    Version Description

    V1.0.0

    Scope

    Topics
    Topic Vocabulary URI
    Hypertension, Blood Pressure, Blood Pressure Determination, Antihypertensive Agents, Medication Adherence, Community Health Workers, Task Shifting, Telemedicine, mHealth, Patient Care Team, Primary Health Care, Health Services Accessibility, Randomized Controlled Trial, Longitudinal Studies, Treatment Outcome, South Africa Africa Health Research Institute www.ahri.org
    Keywords
    Hypertension, blood pressure control, community-based intervention, digital health, eHealth, mHealth, community health workers, anti-hypertensive medication, task shifting, primary care, sub-Saharan Africa, South Africa, non-communicable diseases, health systems strengthening, randomized controlled trial, health services access, treatment outcomes

    Coverage

    Geographic Coverage

    Africa Health Research Institute (AHRI) demographic surveillance area in rural uMkhanyakude district, KwaZulu-Natal
    Universe

    Adults aged =18 years residing in the catchment areas of Nkundusi and Madwaleni Primary Health Care Clinics in uMkhanyakude District (KwaZulu-Natal, South Africa), with uncontrolled blood pressure. Uncontrolled blood pressure was defined as a SBP > 140 mmHg or a diastolic BP > 90mm Hg with at least one prior elevated reading 6 months or more prior. Participants were screened, enrolled, and observed between 30 November 2022 and 30 June 2025.

    Producers and sponsors

    Primary investigators
    Name Affiliation
    Mark J. Siedner AHRI; Massachusetts General Hospital; Harvard Medical School
    Nombulelo Magula University of KwaZulu-Natal Medical School; Clairwood Hospital
    Thomas Gaziano Brigham and Women’s Hospital; Harvard Medical School; Harvard School of Public Health
    Producers
    Name
    Africa Health Research Institute
    Funding Agency/Sponsor
    Name Abbreviation Role
    United States National Institutes of Health NIH Primary funder
    Other Identifications/Acknowledgments
    Name Affiliation Role
    Kathy Baisley AHRI; London School of Hygiene and Tropical Medicine Statistical oversight
    Lusanda Mazibuko Africa Health Research Institute Study statistical lead
    Dickman Gareta Africa Health Research Institute Head of Research Data Management
    Siyabonga Nxumalo Africa Health Research Institute Data management
    Nsika Sithole Africa Health Research Institute Project coordination
    IMPACT-BP CHW Team Africa Health Research Institute Participant engagement and data collection
    IMPACT-BP Clinical Team Africa Health Research Institute Participant clinical monitoring and data collection
    Baptista Joao iMarketing Namibia MHealth application development
    Hosea Kambonde iMarketing Namibia MHealth application development
    Sindy Mthethwa KZN Department of Health Program partnership
    Thabang Manyaapelo Social Science Lead AHRI Social Science Department
    Shafika Abrahams-Gessel Harvard School of Public Health Project Management

    Sampling

    Sampling Procedure

    Participants were recruited from the Nkundusi and Madwaleni primary health care clinics within the AHRI Health and Demographic Surveillance Site (HDSS). All adults presenting at the clinics for primary care during weekdays were screened for eligibility. Eligible participants were aged =18 years, resided in the clinic catchment area, had elevated blood pressure at screening (systolic >140 mmHg or diastolic >90 mmHg), and had at least one previous elevated blood pressure reading documented =6 months prior. Exclusion criteria included pregnancy, breastfeeding, symptomatic elevated blood pressure (>180/110 mmHg), advanced chronic kidney disease (glomerular filtration rate <60 ml/min/1.73m²), and use of =3 full-dose anti-hypertensive medications. Enrolled participants were randomized to one of three study arms (SOC, CHW, eCHW+) in blocks of 9, stratified by clinic and current use of anti-hypertensive therapy.

    Data collection

    Dates of Data Collection
    Start End
    2022-11-01 2025-06-30

    Data processing

    Data Editing

    Study data were entered into REDCap and underwent verification and cleaning prior to analysis. Blood pressure outcomes were averaged as specified, and missing values were identified for potential imputation. Randomisation and intervention adherence data were linked with outcome and covariate data. Data were de-identified prior to analysis. Quality control procedures included duplicate entry checks, automated range checks for blood pressure, and consistency checks across visits.

    Data Access

    Access conditions

    The representative of the Receiving Organization agrees to comply with the following conditions:

    1. Access to the restricted data will be limited to the Lead Researcher and other members of the research team listed in this request.
    2. Copies of the restricted data or any data created on the basis of the original data will not be copied or made available to anyone other than those mentioned in this Data Access Agreement, unless formally authorized by the Data Archive.
    3. The data will only be processed for the stated statistical and research purpose. They will be used for solely for reporting of aggregated information, and not for investigation of specific individuals or organizations. Data will not in any way be used for any administrative, proprietary or law enforcement purposes.
    4. The Lead Researcher must state if it is their intention to match the restricted microdata with any other micro-dataset. If any matching is to take place, details must be provided of the datasets to be matched and of the reasons for the matching. Any datasets created as a result of matching will be considered to be restricted and must comply with the terms of this Data Access Agreement.
    5. The Lead Researcher undertakes that no attempt will be made to identify any individual person, family, business, enterprise or organization. If such a unique disclosure is made inadvertently, no use will be made of the identity of any person or establishment discovered and full details will be reported to the Data Archive. The identification will not be revealed to any other person not included in the Data Access Agreement.
    6. The Lead Researcher will implement security measures to prevent unauthorized access to licensed microdata acquired from the Data Archive. The microdata must be destroyed upon the completion of this research, unless the Data Archive obtains satisfactory guarantee that the data can be secured and provides written authorization to the Receiving Organization to retain them. Destruction of the microdata will be confirmed in writing by the Lead Researcher to the Data Archive.
    7. Any books, articles, conference papers, theses, dissertations, reports, or other publications that employ data obtained from the Data Archive will cite the source of data in accordance with the citation requirement provided with the dataset.
    8. An electronic copy of all reports and publications based on the requested data will be sent to the Data Archive.
    9. The original collector of the data, the Data Archive, and the relevant funding agencies bear no responsibility for use of the data or for interpretations or inferences based upon such uses.
    10. This agreement will come into force on the date that approval is given for access to the restricted dataset and remain in force until the completion date of the project or an earlier date if the project is completed ahead of time.
    11. If there are any changes to the project specification, security arrangements, personnel or organization detailed in this application form, it is the responsibility of the Lead Researcher to seek the agreement of the Data Archive to these changes. Where there is a change to the employer organization of the Lead Researcher this will involve a new application being made and termination of the original project.
    12. Breaches of the agreement will be taken seriously and the Data Archive will take action against those responsible for the lapse if willful or accidental. Failure to comply with the directions of the Data Archive will be deemed to be a major breach of the agreement and may involve recourse to legal proceedings. The Data Archive will maintain and share with partner data archives a register of those individuals and organizations which are responsible for breaching the terms of the Data Access Agreement and will impose sanctions on release of future data to these parties.
    Citation requirements

    Siedner, M. J., & Magula, N. (2026). Implementation Evaluation of a Combination Intervention for Sustainable Blood Pressure Control in Rural KwaZulu-Natal, South Africa [Data set]. Africa Health Research Institute.
    DOI: https://doi.org/10.23664/AHRI.IMPACTBP

    Metadata production

    DDI Document ID

    DDI.AHRI.ImpactBP
    Producers
    Name Abbreviation
    Africa Health Research Institute AHRI
    Back to Catalog