Home environmental interventions for prevention of respiratory tract infections: A systematic review and meta-analysis

Poor housing conditions have been associated with increased risks of respiratory infections. This review aims to determine whether modifying the physical environment of the home has benefits in reducing respiratory infections. We performed a systematic review and meta-analysis of the effectiveness of home environmental interventions for preventing respiratory tract infections. Ten electronic databases were searched to identify randomized controlled trials published from inception to July 31, 2020. Random-effects meta-analyses were used to assess the study outcomes. Our search identified 14 eligible studies across 12 countries, which comprised 87,428 households in total. The type of interventions on home environment included kitchen appliance and design, water supply and sanitation, house insulation, and home heating. Meta-analysis indicated a potential benefit of home environmental interventions in preventing overall respiratory tract infections (Absolute RR=0.89, 95% CI=0.78-1.01, p=0.07; Pooled adjusted RR=0.72, 95% CI=0.63-0.84, p<0.0001). Subgroup analyses depicted that home environmental interventions had no significant impact on lower respiratory tract infections, pneumonia, and severe pneumonia. A protective effect against respiratory infections was observed in high income country setting (RR=0.82, 95% CI=0.78-0.87, p<0.00001). Home environmental interventions have the potential to reduce morbidity of respiratory tract infections. The lack of significant impact from stand-alone housing interventions suggests that multicomponent interventions should be implemented in tandem with high-quality health systems.