Studies of the adverse impacts of high temperature on human health have been primarily focusing on urban areas, due in part to the facts that urban centers generally have higher population density and are often significantly warmer than its surrounding rural areas (Heat Island Effect), and thus urban areas are considered to be more vulnerable to summer heat. However, heat vulnerability can also be affected by other population characteristics such as age, education, income and social isolation, which are likely to mark greater vulnerability among rural population. Here we explore the vulnerability to heat-related mortality in rural areas through a systematic review and meta-analysis of existing evidence. We searched studies that examined the association between high ambient temperature and morality in rural areas published in English between 2000 and 2016. Heat-mortality effect estimates from selected studies are grouped into two: (1) Rural effect estimates (RRrural) and their corresponding urban effect estimates (RRurban), from studies that reported risk estimates for both urban and their surrounding rural areas (7 studies included); (2) Rural effect estimates only (12 studies included). For Group 1, we performed a meta-analysis of the ratio of the rural estimate to the urban estimate in order to compare the magnitude of effects in rural versus urban areas. For Group 2, we performed a meta-analysis of the effect estimates in rural areas only. The pooled ratio estimate (RRrural/RRurban) for Group 1 is 1.051 (95% CI: 0.954, 1.160), which indicates the rural relative risk is about 5% larger than the urban relative risk. The pooled estimate for Group 2 is 1.191 (95% CI: 1.13, 1.251). Our preliminary results suggest that vulnerability to heat in rural areas may be similar to or even higher than urban areas, indicating that more studies are needed to understand rural vulnerability to heat-related hazards.
Available at: http://works.bepress.com/ying-li/48/