Completed Public Health & Healthcare Lungs & Breathing

Sustainable Community Action for Lung hEalth (SCALE): a cluster randomised trial in Blantyre, Malawi

Funder Wellcome Charity-funded
Recipient organisation London School of Hygiene & Tropical Medicine
Funding £4.1M
Period Sept 2016 — Sept 2021

In plain English

AI plain-English summary

Every six months, community health workers in Blantyre, Malawi, will knock on doors and offer TB and HIV testing to adults with a chronic cough, adding monthly volunteer group meetings to boost participation and sample collection. This matters because standard TB case-finding often misses people who are infectious but not sick enough to visit a clinic. Four earlier studies suggested that periodic, community-wide screening can reduce TB prevalence at the population level, but funders and health ministries have hesitated to scale it up without definitive evidence from a large, randomised trial. SCALE will provide that evidence by comparing TB prevalence in 54,000 adults across communities that receive the intervention versus those that do not. If the trial shows a 28 to 35 percent reduction in TB prevalence, it could transform how countries across sub-Saharan Africa approach TB control. Instead of waiting for symptomatic patients to seek care, health systems could adopt routine, community-led screening rounds that catch infections earlier, interrupt transmission, and reduce the burden on overstretched clinics. A secondary measure—tuberculin skin test positivity in children aged 12 to 36 months—will also indicate whether the intervention protects the most vulnerable. The process evaluation, tracking a “peak” in case-notification rates after each screening round, will provide further evidence of real-world effectiveness.

View original technical description
A cluster-randomised trial (CRT) investigating undiagnosed culture-positive TB after 5 rounds of periodic (6-monthly) TB/HIV case-finding targeting adults with chronic cough in the community. This approach has evidence of population-level effect from 4 different studies, but willingness to scale-up regionally is hampered by lack of definitive CRT results. Symptomatic adults will be offered TB and HIV diagnosis (sputum microscopy and supervised HIV self-testing [HIVST]). A community-led component, based on monthly volunteer groups meetings, will be added to provide community mobilization and pre-distribution of containers and HIVST kits before outreach team visits. Standard participatory learning approaches will be used to train Volunteer Groups to contribute to TB/HIV prevention and maintain their commitment. In both arms, facility-based management of suspected TB will be strengthened, and a pre-intervention radiological and culture-based TB prevalence survey will be used to enable before-and-after comparisons and adjust for imbalance between arms. The primary outcome will be comparison between arms of TB prevalence 54,000 adults, powered to detect a 28% to 35% difference between arms. The secondary outcome will compare tuberculin skin test positivity in children aged 12 to 36 months between arms. Process evaluation will include cluster-level case-notification rates: a “peak” providing supportive evidence of intervention effectiveness.

View the original record at the funder ↗

Researchers

Liz Corbett (EPMC Awardee)

Related Research

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Evaluation of a Mask Aerosol Sampling System (MASS) as an Active Case Finding Approach Focused on Infectious TB in Low-Resource Settings.
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The HomeACF Study: A household cluster randomised trial of case-finding and intensive prevention for HIV and TB
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Original classification

Senior Research Fellowship Clinical Renewal

Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.