Impact of a Solar Lighting Intervention on Social Determinants of Health in Rural Uganda: A Mixed Methods, Randomized Controlled Trial

Background: Clinical trials to reduce household air pollution have largely focused on cookstoves and have been in part limited by suboptimal adoption of cleaner cooking technologies. Less is known about the adoption and perceptions of clean lighting interventions. Methods: As part of a randomized controlled trial of indoor solar lighting systems (ClinicalTrials.gov NCT03351504), we conducted a mixed methods study to identify contextual factors determining uptake and perception of the solar lighting intervention. Sensors were incorporated into the intervention solar lighting system to measure uptake and use over time. Health-related quality of life was measured with the EQ-5D-5L. Qualitative interviews were conducted with all trial participants. Findings: Uptake of the intervention solar lighting system was high with daily use averaging 8·23 ± 5·30 hours per day. In mixed effects regression models, the intervention solar lighting system increased the EQ5D index by 0·083 [0·024 - 0·141], p = 0·006. Qualitative data suggest that solar lighting was associated with numerous benefits to study participants, including improved household finances, improved educational performance of children, increased household safety, improved family and community cohesion, and improved perceived household health. Interpretation: Uptake of the solar lighting intervention was high and led to improved health-related quality of life. The solar lighting intervention was a transformative household energy technology which improve multiple domains of the Social Determinants of Health (SDOH). Trials focused only on traditional health outcomes may underestimate the overall value of clean household energy interventions to the end user. Trial Registration: ClinicalTrials.gov NCT03351504 Funding Statement: US National Institutes of Health, Harvard School of Public Health, American Thoracic Society, Massachusetts General Hospital Declaration of Interests: We declare no competing interests. Ethics Approval Statement: This study was approved by the Mbarara University of Science and Technology (Protocol #02/11-16) and the Partners Human Research Committee (Protocol 2017P000306/PHS), the Ugandan National Council of Science and Technology (Protocol #PS 42) and the Ugandan President’s office.