Protective effects of low temperature on the risk of hospitalization for mental and behavioral disorders: a time series study

The high incidence of mental illness worldwide is a substantial economic burden on society. Temperature and the occurrence of mental and behavioral disorders (MDs) seem to have a relationship, but this has not been widely researched. Therefore, this study aimed to investigate the effect of temperature on the hospitalization rate of patients with MDs in a temperate monsoon climate region of northern China. Patients with MDs hospitalized in the Mental Health Center of Hebei Medical University and Psychology Department in The third Hospital of Shijiazhuang, China, from January 2014 to December 2019 were included in the study. The delayed exposure – response relationship between temperature and the number of hospitalized MDs patients was analyzed using a quasi-Poisson generalized additive model combined with a distributed lag nonlinear model. With the reference of 15.3°C (temperature with the minimum hospitalizations), the single lag effect of low temperature (−2°C, 10th percentile) increased the hospitalization of patients with MDs, while the cumulative effect decreased the risk of hospitalization for some MD subtypes; it was an acute protective effect. The single and cumulative lag effect of high temperature statistically increased the hospitalization rates of patients with MDs. The optimum temperature for each subtype was different, and the males and the younger age group were more susceptible to high temperatures. Low temperature has an acute protective effect on the hospitalization of patients with MDs. In comparison, high temperature increases hospitalization rates. Men and younger people are more affected by temperature, which provides early warning and health intervention measures for patients with corresponding temperature changes.

全球范围内精神疾病的高发病率给社会造成了沉重的经济负担。气温与精神与行为障碍（Mental and Behavioral Disorders, MDs）的发生似乎存在关联，但相关研究尚未得到广泛开展。为此，本研究旨在探讨气温对中国北方温带季风气候区精神与行为障碍患者住院率的影响。本研究纳入了2014年1月至2019年12月期间，在中国河北医科大学精神卫生中心以及石家庄市第三医院心理科住院的精神与行为障碍患者。采用拟泊松广义相加模型结合分布滞后非线性模型，分析气温与精神与行为障碍住院患者人数之间的滞后暴露-反应关系。以15.3℃（住院人数最少的气温值）作为参照基准，低温（-2℃，即第10百分位气温）的单滞后效应会增加精神与行为障碍患者的住院人数，而其累积效应则降低了部分精神与行为障碍亚型的住院风险，呈现急性保护效应；高温的单滞后效应与累积滞后效应均在统计学上显著升高了精神与行为障碍患者的住院率。各精神与行为障碍亚型的最优温度存在差异，男性及年轻群体对高温更为易感。综上，低温对精神与行为障碍患者的住院人数呈现急性保护效应，而高温则会提升其住院率。男性与年轻群体受气温影响更为显著，本研究结果可为对应气温变化下的患者预警及健康干预措施提供参考依据。