Solar-powered O2 delivery for the treatment of children with hypoxaemia in Uganda: a stepped-wedge, cluster randomised controlled trial

Background Supplemental O-2 is not always available at health facilities in low-income and middle-income countries (LMICs). Solar-powered O-2 delivery can overcome gaps in O-2 access, generating O-2 independent of grid electricity. We hypothesized that installation of solar-powered O-2 systems on the paediatrics ward of rural Ugandan hospitals would lead to a reduction in mortality among hypoxaemic children. Methods In this pragmatic, country-wide, stepped-wedge, cluster randomised controlled trial, solar-powered O-2 systems (ie, photovoltaic cells, battery bank, and O-2 concentrator) were sequentially installed at 20 rural health facilities in Uganda. Sites were selected for inclusion based on the following criteria: District Hospital or Health Centre IV with paediatric inpatient services; supplemental O-2 on the paediatric ward was not available or was unreliable; and adequate space to install solar panels, a battery bank, and electrical wiring. Allocation concealment was achieved for sites up to 2 weeks before installation, but the study was not masked overall. Children younger than 5 years admitted to hospital with hypoxaemia and respiratory signs were included. The primary outcome was mortality within 48 h of detection of hypoxaemia. The statistical analysis used a linear mixed effects logistic regression model accounting for cluster as random effect and calendar time as fixed effect. The trial is registered at ClinicalTrials.gov, NCT03851783. Findings Between June 28, 2019, and Nov 30, 2021, 2409 children were enrolled across 20 hospitals and, after exclusions, 2405 children were analysed. 964 children were enrolled before site randomisation and 1441 children were enrolled after site randomisation (intention to treat). There were 104 deaths, 91 of which occurred within 48 h of detection of hypoxaemia. The 48 h mortality was 49 (5 center dot 1%) of 964 children before randomisation and 42 (2 center dot 9%) of 1440 (one individual did not have vital status documented at 48 h) after randomisation (adjusted odds ratio 0 center dot 50, 95% CI 0 center dot 27-0 center dot 91, p=0 center dot 023). Results were sensitive to alternative parameterisations of the secular trend. There was a relative risk reduction of 48 center dot 7% (95% CI 8 center dot 5-71 center dot 5), and a number needed to treat with solar-powered O-2 of 45 (95% CI 28-230) to save one life. Use of O-2 increased from 484 (50 center dot 2%) of 964 children before randomisation to 1424 (98 center dot 8%) of 1441 children after randomisation (p<0 center dot 0001). Adverse events were similar before and after randomisation and were not considered to be related to the intervention. The estimated cost-effectiveness was US$25 (6-505) per disability-adjusted life-year saved. Interpretation This stepped-wedge, cluster randomised controlled trial shows the mortality benefit of improving O-2 access with solar-powered O-2. This study could serve as a model for scale-up of solar-powered O-2 as one solution to O-2 insecurity in LMICs. Copyright (c) 2024 Elsevier Ltd. All rights reserved.