Projections of excess mortality related to diurnal temperature range under climate change scenarios: a multi-country modelling study

Publié le 1 Novembre 2020
Mis à jour le 08 décembre 2020

Background: various retrospective studies have reported on the increase of mortality risk due to higher diurnal temperature range (DTR). This study projects the effect of DTR on future mortality across 445 communities in 20 countries and regions. Methods: DTR-related mortality risk was estimated on the basis of the historical daily time-series of mortality and weather factors from Jan 1, 1985, to Dec 31, 2015, with data for 445 communities across 20 countries and regions, from the Multi-Country Multi-City Collaborative Research Network. We obtained daily projected temperature series associated with four climate change scenarios, using the four representative concentration pathways (RCPs) described by the Intergovernmental Panel on Climate Change, from the lowest to the highest emission scenarios (RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5). Excess deaths attributable to the DTR during the current (1985-2015) and future (2020-99) periods were projected using daily DTR series under the four scenarios. Future excess deaths were calculated on the basis of assumptions that warmer long-term average temperatures affect or do not affect the DTR-related mortality risk. Findings: the time-series analyses results showed that DTR was associated with excess mortality. Under the unmitigated climate change scenario (RCP 8.5), the future average DTR is projected to increase in most countries and regions (by -0·4 to 1·6°C), particularly in the USA, south-central Europe, Mexico, and South Africa. The excess deaths currently attributable to DTR were estimated to be 0·2-7·4%. Furthermore, the DTR-related mortality risk increased as the long-term average temperature increased; in the linear mixed model with the assumption of an interactive effect with long-term average temperature, we estimated 0·05% additional DTR mortality risk per 1°C increase in average temperature. Based on the interaction with long-term average temperature, the DTR-related excess deaths are projected to increase in all countries or regions by 1·4-10·3% in 2090-99. Interpretation: this study suggests that globally, DTR-related excess mortality might increase under climate change, and this increasing pattern is likely to vary between countries and regions. Considering climatic changes, our findings could contribute to public health interventions aimed at reducing the impact of DTR on human health.

Auteur : Lee Whanhee, Kim Yoonhee, Sera Francesco, Gasparrini Antonio, Park Rokjin, Michelle Choi Hayon, Prifti Kristi, Bell Michelle L, Abrutzky Rosana, Guo Yuming, Tong Shilu, de Sousa Zanotti Stagliorio Coelho Micheline, Nascimento Saldiva Paulo Hilario, Lavigne Eric, Orru Hans, Indermitte Ene, Jaakkola Jouni J K, Ryti Niilo R I, Pascal Mathilde, Goodman Patrick, Zeka Ariana, Hashizume Masahiro, Honda Yasushi, Hurtado Diaz Magali, César Cruz Julio, Overcenco Ala, Nunes Baltazar, Madureira Joana, Scovronick Noah, Acquaotta Fiorella, Tobias Aurelio, Vicedo-Cabrera Ana Maria, Ragettli Martina S, Leon Guo Yue-Liang, Chen Bing-Yu, Li Shanshan, Armstrong Ben, Zanobetti Antonella, Schwartz Joel, Kim Ho
The Lancet Planetary Health, 2020, vol. 4, n°. 11, p. e512-21