LAUSR

Introduction: Health effects of heat and cold in urban areas are well known, while evidence on suburban and rural areas is scarce. Aim: To estimate the short-term effects of heat and cold on respiratory mortality (5 regions) and hospital admissions for respiratory disease (nationwide) over 10years in Italy. We evaluated possible changes in the effects by gender, age ( 75 years) and level of urbanization. Methods: Daily mean air temperature with a spatial resolution of 1x1km was derived using satellite land surface temperature(LST), observed temperature data and spatio-temporal land use and land cover predictors. Non-linear distributed lag (DLNM) models, adjusted for temporal trends, PM10 and influenza were used to estimate the association between temperature and respiratory mortality/hospitalizations at municipal level. The percent increase in risk(IR%), for temperature increases between the 75th and 99th percentile (heat) and decreases from the 25th to the 1st percentile (cold) are reported. Risk estimates by age, gender and urbanization(high, medium, low) were also calculated. Results: The pooled effect estimates for heat and cold on respiratory mortality were 1.52%(95%CI:1.35-1.71%) and 1.43%(95%CI:1.24-1.65%) respectively. A greater risk in mortality was found among the very old(75+) and in suburban and rural areas. For hospital admissions, significant risks were only observed for heat (IR:95%CI=1.08%:1.06-1.11%) with some heterogeneity among regions. Heat-related admissions were greater among the elderly and in urban areas. Conclusions: Extreme temperatures are a risk factor in both urban and rural areas.