Regional Assessment of Temperature-Related Mortality in Finland

Abstract

The aim of this study was to assess regional differences in temperature–mortality relationships across 21 hospital districts in Finland. The temperature dependence of the daily number of all-cause, all-aged deaths during 2000–2014 was studied in each hospital district by using daily mean temperatures, spatially averaged across each hospital district, to describe exposure to heat stress and cold stress. The relationships were modelled using distributed lag non-linear models (DLNM). In a simple model version, no delayed impacts of heat and cold on mortality were taken into account, whereas a more complex version included delayed impacts up to 25 days. A meta-analysis with selected climatic and sociodemographic covariates was conducted to study differences in the relationships between hospital districts. A pooled mortality-temperature relationship was produced to describe the average relationship in Finland. The simple DLNM model version without lag gave U-shaped dependencies of mortality on temperature almost without exception. The outputs of the model version with a 25-day lag were also U-shaped in most hospital districts. According to the meta-analysis, the differences in the temperature-mortality relationships between hospital districts were not statistically significant on the absolute temperature scale, meaning that the pooled mortality–temperature relationship can be applied to the whole country. However, on a relative temperature scale, heterogeneity was found, and the meta-regression suggested that morbidity index and population in the hospital districts might explain some of this heterogeneity. The pooled estimate for the relative risk (RR) of mortality at a daily mean temperature of 24 °C was 1.16 (95% CI 1.12–1.20) with reference at 14 °C, which is the minimum mortality temperature (MMT) of the pooled relationship. On the cold side, the RR at a daily mean temperature of −20 °C was 1.14 (95% CI 1.12–1.16). On a relative scale of daily mean temperature, the MMT was found at the 79th percentile.

Mortality Related to Cold Temperatures in Two Capitals of the Baltics: Tallinn and Riga

“…Colder temperatures than the MMT during the cold season significantly increased all-cause mortality, both in Tallinn and in Riga. The all-cause mortality relative risks in Tallinn (RR = 1.28, 95% CI 1.01–1.62) are consistent with relative risk assessments in a neighboring country, Finland, where researchers identified all-cause mortality risks (RR = 1.26 and RR = 1.20) in two investigated districts [3]. In Riga, the all-cause mortality risk during the 21-day period (RR = 1.41, 95% CI 1.11–1.79) was higher than in Tallinn and in Finland, albeit not to a statistically significant extent.…”

“…With ongoing climate change, the health effects of heat waves and high temperatures have been thoroughly documented throughout the world [1], in Europe [2,3,4], and specifically in Estonia [5]. Even though it is likely that more frequent heat waves will occur in the future, the climate in the Baltics is generally cold, and the majority of deaths due to non-optimal temperatures in these areas are likely due to cold temperatures, as has been reported for neighboring countries like Sweden [6] and Finland [3]. The impact of cold temperatures on mortality is a phenomenon that is not exclusive to northern countries.…”

Natural Hazards and Extreme Events in the Baltic Sea region

“…More recent studies conducted e.g., for Poland (Owczarek and Filipiak, 2016), the three Baltic States (Jaagus et al, 2014(Jaagus et al, , 2017, Finland (Irannezhad et al, 2015;Aalto et al 2016), Sweden (SMHI, 2019 and the whole Baltic Sea drainage basin , indicate that mean temperatures continue to rise in the region and that the increases are larger than the global average warming. temperatures pose a significant risk to health also in the current-day climate (e.g., Kollanus and Lanki 2014;Åström et al, 2016;Ruuhela et al, 2018).…”

Varm sommer 2018 – økt dødelighet blant eldre?

“…Ved hetebølger i Europa er det påvist overdødelighet blant eldre personer (4,5). En studie fra Finland har undersøkt forholdet mellom daglig middeltemperatur og dødelighet i de nordiske landene, og funnet at både svaert lave og høye temperaturer ga økt dødelighet (6). I Sverige er det vist økning i både total dødelighet og dødelighet av hjerte-og karsykdommer i forbindelse med hetebølger (7).…”