Urban green space and health in low and middle-income countries: A critical review

Studies from high income, mostly westernised countries tend to report health benefits from urban green spaces. Generalizability of this evidence for the 125 low and middle-income countries (LMICs) is debatable. This systematic review explored and synthesized the quality of green space-health studies reported from LMICs. Following PRISMA guidelines, 22 studies were found through a systematic search and after applying inclusion criteria by two researchers. Quantitative and qualitative synthesis of these studies included a study quality assessment using the National Institutes of Health quality assessment tool for observational cohort and cross-sectional studies. The 22 studies were conducted in 11 LMICs and mostly of the cross-sectional design. Health outcomes include mental and physical health, wellbeing. Green space and health outcomes were mostly measured by the subjective tool, such as by the perception of the sample population; most reporting green space benefits except the study conducted on a slum population and two studies measured physical health outcomes. Only 14 studies adjusted different moderating variables in the quantitative analysis. Three studies explored mediation analyses and reported physical activity and perceived restorativeness of UGS to be the strongest potential pathways to better health. Lack of adherence to observation study design protocols resulted in the studies to have moderate to low quality. The enquiry on the potential health benefits of green space in LMICs is an important gap in knowledge. The evidence in the LMICs is limited by the quality of the studies. More research, especially longitudinal studies that make use of objective indicators of green space design, utilisation and health indicators in a wider range of LMICs is warranted.