Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
PLoS One. 2013 Aug 14;8(8):e71689. doi: 10.1371/journal.pone.0071689. eCollection 2013.
Drowning deaths are devastating and preventable. Public perception does not regard hot weather as a common scenario for drowning deaths. The objective of our study was to test the association between hot weather and drowning risk.
We conducted a retrospective case-crossover analysis of all unintentional drowning deaths in Ontario, Canada from 1999 to 2009. Demographic data were obtained from the Office of the Chief Coroner. Weather data were obtained from Environment Canada. We used the pair-matched analytic approach for the case-crossover design to contrast the weather on the date of the drowning with the weather at the same location one week prior (control period).
We identified 1243 drowning deaths. The mean age was 40 years, 82% were male, and most events (71%) occurred in open water. The pair-matched analytic approach indicated that temperatures exceeding 30°C were associated with a 69% increase in the risk of outdoor drowning (OR = 1.69, 95% CI 1.23-2.25, p = 0.001). For indoor drowning, however, temperatures exceeding 30°C were not associated with a statistically significant increase in the risk of drowning (OR = 1.50, 95% CI 0.53-4.21, p = 0.442). Adult men were specifically prone to drown in hot weather (OR 1.67, 95% CI 1.19-2.34, p = 0.003) yet an apparent increase in risk extended to both genders and all age groups.
Contrary to popular belief, hot weather rather than cold stormy weather increases the risk of drowning. An awareness of this risk might encourage greater use of drowning prevention strategies known to save lives.
溺水死亡是毁灭性的，也是可以预防的。公众普遍认为，炎热的天气并非导致溺水死亡的常见因素。本研究旨在检验炎热天气与溺水风险之间的关联。
我们对加拿大安大略省 1999 年至 2009 年期间所有非故意溺水死亡事件进行了回顾性病例交叉分析。人口统计学数据来源于首席验尸官办公室。气象数据来源于加拿大环境部。我们采用病例交叉设计的配对分析方法，将溺水发生日的天气与前一周同一地点的天气（对照期）进行对比。
我们共确定了 1243 例溺水死亡事件。平均年龄为 40 岁，82%为男性，大多数事件（71%）发生在开阔水域。配对分析表明，当温度超过 30°C 时，户外溺水的风险增加 69%（OR=1.69，95%CI 1.23-2.25，p=0.001）。然而，对于室内溺水，温度超过 30°C 与溺水风险的统计学显著增加无关（OR=1.50，95%CI 0.53-4.21，p=0.442）。成年男性尤其容易在炎热天气中溺水（OR 1.67，95%CI 1.19-2.34，p=0.003），但风险的明显增加扩展到了两性和所有年龄段。
与普遍看法相反，炎热的天气而非寒冷多风暴的天气会增加溺水风险。对这种风险的认识可能会鼓励更多地使用已知可以拯救生命的溺水预防策略。
