Effects of ambient temperature on ambulance emergency call-outs in the subtropical city of Shenzhen, China

Abstract

The associations between meteorological factors and mortality have been well documented worldwide, but limited evidence is available for the non-fatal health impacts of ambient temperature, particularly there are few population-based investigations on the impacts of emergency ambulance dispatches in Asia. In this study, based on 809,906 ambulance emergency call-outs (AECOs) for the total population from 2010–2016 in the subtropical city of Shenzhen, China, a Poisson regression combined with a distributed lag nonlinear model was used to simultaneously assess the nonlinear and lag effects of daily mean temperature on AECOs. Stratified analyses by age and sex were performed to identify vulnerable subpopulations. A U-shaped relationship was found between temperature and AECOs. Cold effects were delayed and persisted for 3–4 weeks, with a cumulative relative risk (RR) and 95% confidence interval (CI) of 1.23 (1.10–1.38) and 1.25 (1.16–1.35) over lag 0–28 when comparing the 1st and 5th percentile of the temperature distribution to the optimal (i.e. minimum AECOs) temperature, respectively. Hot effects were immediate and diminished quickly in 5 days, with an increase of 19% (RR = 1.19, 95%CI: 1.14–1.23) and 21% (RR = 1.21, 95%CI: 1.16–1.26) in AECOs over lag 0–5 when comparing the 95th and 99th percentile of temperature to the optimal temperature. Children and the elderly were more vulnerable to cold effects. The youth and middle-aged people suffered more from high temperature. The effects of temperature were similar between males and females. In summary, significant increases were observed in the frequency of AECOs during cold and hot days, and the weather-associated increases in AECOs are different among age groups. This information has valuable implications in ambulance demand prediction and service provision planning.

The Effects of Temperature on Accident and Emergency Department Attendances in London: A Time-Series Regression Analysis

“…Several combinations of lag days were assessed in the sensitivity analysis (14-day lag and 21-day lag), but the relationship remained mostly flat. Other international studies found a U-shaped relationship between temperature and A&E department attendances similar to that seen with mortality data [8,15]. A study conducted in Southern New England demonstrated that both high and low temperatures were associated with higher rates of all-cause A&E department attendances and that the slope of the exposure-response function was steeper for high temperatures than for low temperatures [8].…”

“…The authors found a positive correlation between maximum daily temperature and non-trauma attendance. Studies from Australia, China, Singapore and Brazil have associated daily patient attendances with factors such as public holidays, precipitation, temperature, air pollution and relative humidity [8,[14][15][16][17]. In the United Kingdom (UK), only a few studies have examined the effect of temperature on overall and multi-cause attendance rates.…”

Diagnostic performance of anthropometric measurements in detecting elevated serum alanine aminotransferase: a school-based screening of 7271 Shenzhen adolescents

“…Situated approximately 1˚ south of the Tropic of Cancer, within the Pearl River Delta region of Guangdong province, and bordered Hong Kong, Shenzhen is one of the 4 first-tier cities in mainland China, the first Special Economic Zone of China (established in 1980), and a major financial centre and the worldly largest manufacturing base 22,23 . The population and economy have grown rapidly, with a total gross domestic product (GDP) of 255 billion USD and approximate 25,000 USD per capita in 2015 22,24 .…”

Diagnostic performance of individual characteristics and anthropometric measurements in detecting elevated serum alanine aminotransferase among children and adolescents

“…Shenzhen is one of the 4 first-tier cities in mainland China and a major financial centre and the worldly largest manufacturing base [26]. The population and economy have grown rapidly, with a total gross domestic product of 255 billion USD in 2015 [27].…”