The association between high ambient temperature and mortality in the Mediterranean basin: a systematic review and meta-analysis

Abstract

AbstractBackgroundThe effect of hot ambient temperature on mortality differs between geographical locations. The Mediterranean basin has been identified as one of the most prominent “hot-spots” in the world in terms of vulnerability to climate change. No recent, large synthesis of the estimated effects in the Mediterranean basin has been conducted.MethodsA systematic review was conducted across three major databases to retrieve effect estimates from time-series or case-crossover studies on temperature and mortality performed in the Mediterranean basin countries, between 2000-2021. Of all reviewed studies, n=16 were eligible for inclusion in the meta-analysis. Estimates were pooled using a random-effects model. Subgroup analyses were performed for death-cause, age-group, region, and climate type. Meta-regression was performed with respect to national Gross Domestic Product (GDP) per capita, latitude and longitude, and local temperature thresholds.ResultsWe found an increased risk of all-cause mortality due to ambient heat exposure in the Mediterranean basin, with a pooled RR=1.035 (95%CI 1.028-1.041) per 1°C increase in temperature above local thresholds (I2=79%). Risk was highest for respiratory (RR=1.063, 95% CI 1.052-1.074) and cardiovascular (RR=1.046, 95% CI 1.036-1.057) mortality.ConclusionsHot ambient temperatures increase the mortality risk across the Mediterranean basin. This is increasingly important for public health processes in the Mediterranean basin countries in light of the climate changes already noticed in this area. Further high-quality studies, especially in North African, Asian Mediterranean, and eastern European countries, are needed to bolster regional preparedness against future heat-related health burdens.Key MessagesHigh ambient temperatures affect short-term mortality across the Mediterranean basin countries.Risk is highest for respiratory and cardiovascular mortality.In light of climate change, this is an increasingly important public health concern. Further high-quality studies, especially in North African, Asian Mediterranean and eastern European countries, are needed to help regions prepare for future heat-related health burdens.