Abstract

Background:

Many studies have investigated the devastating health effects of heat waves, but less is known about health risks related to cold spells, despite evidence that extreme cold may contribute to a larger proportion of deaths.

Objectives:

We aimed to systematically investigate the association between cold spells and mortality in Japan.

Methods:

Daily data for weather conditions and 12 common causes of death during the 1972–2015 cold seasons (November–March) were obtained from 47 Japanese prefectures. Cold spells were defined as $\ge 2$ consecutive days with daily mean temperatures $\le 5\text{th}$ percentile for the cold season in each prefecture. Quasi-Poisson regression was combined with a distributed lag model to estimate prefecture-specific associations, and pooled associations at the national level were obtained through random-effects meta-analysis. The potential influence of cold spell characteristics (intensity, duration, and timing in season) on associations between cold spells and mortality was examined using a similar two-stage approach. Temporal trends were investigated using a meta-regression model.

Results:

A total of 18,139,498 deaths were recorded during study period. Mortality was significantly higher during cold spell days vs. other days for all selected causes of death. Mortality due to age-related physical debilitation was more strongly associated with cold spells than with other causes of death. Associations between cold spells and mortality from all causes and several more specific outcomes were stronger for longer and more intense cold spells and for cold spells earlier in the cold season. However, although all outcomes were positively associated with cold spell duration, findings for cold spell intensity and seasonal timing were heterogeneous across the outcomes. Associations between cold spells and mortality due to cerebrovascular disease, cerebral infarction, and age-related physical debility decreased in magnitude over time, whereas temporal trends were relatively flat for all-cause mortality and other outcomes.

Discussion:

Our findings may have implications for establishing tailored public health strategies to prevent avoidable cold spell–related health consequences. https://doi.org/10.1289/EHP7109

中文翻译：

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日本 47 个县的感冒症状和特定原因死亡率：系统评估

摘要

背景：

许多研究调查了热浪对健康的破坏性影响，但对与寒潮相关的健康风险知之甚少，尽管有证据表明极端寒冷可能导致更大比例的死亡。

目标：

我们旨在系统地调查日本寒潮与死亡率之间的关联。

方法：

从日本 47 个县获得了 1972-2015 年寒冷季节（11 月至 3 月）的天气状况和 12 种常见死亡原因的每日数据。寒潮被定义为$\ge 2$ 具有每日平均温度的连续天数 $\le 5\text{日}$各州寒冷季节的百分位。准泊松回归结合分布式滞后模型来估计特定地区的关联，并通过随机效应荟萃分析获得国家层面的汇总关联。使用类似的两阶段方法检查了寒流特征（强度、持续时间和季节时间）对寒流和死亡率之间关联的潜在影响。使用元回归模型研究时间趋势。

结果：

研究期间共记录了 18,139,498 人死亡。对于所有选定的死因，寒冷天气期间的死亡率明显高于其他日子。与其他死亡原因相比，与年龄相关的身体虚弱导致的死亡率与寒潮的关联度更高。寒流与各种原因造成的死亡率和几个更具体的结果之间的关联对于更长和更强烈的寒流以及在寒冷季节较早的寒流来说更强。然而，尽管所有结果都与寒潮持续时间呈正相关，但寒潮强度和季节性时间的发现在结果中存在差异。随着时间的推移，寒潮与脑血管疾病、脑梗塞和与年龄相关的身体虚弱导致的死亡率之间的关联程度下降，

讨论：

我们的研究结果可能对制定量身定制的公共卫生策略以预防可避免的与寒潮相关的健康后果有影响。https://doi.org/10.1289/EHP7109