Azhar Gulrez Shah, Mavalankar Dileep, Nori-Sarma Amruta, Rajiva Ajit, Dutta Priya, Jaiswal Anjali, Sheffield Perry, Knowlton Kim, Hess Jeremy J
Indian Institute of Public Health, Ahmedabad, Gujarat, India; Public Health Foundation of India, New Delhi, India.
Indian Institute of Public Health, Ahmedabad, Gujarat, India; Columbia Mailman School of Public Health, New York, New York, United States of America.
PLoS One. 2014 Mar 14;9(3):e91831. doi: 10.1371/journal.pone.0091831. eCollection 2014.
In the recent past, spells of extreme heat associated with appreciable mortality have been documented in developed countries, including North America and Europe. However, far fewer research reports are available from developing countries or specific cities in South Asia. In May 2010, Ahmedabad, India, faced a heat wave where the temperatures reached a high of 46.8 °C with an apparent increase in mortality. The purpose of this study is to characterize the heat wave impact and assess the associated excess mortality.
We conducted an analysis of all-cause mortality associated with a May 2010 heat wave in Ahmedabad, Gujarat, India, to determine whether extreme heat leads to excess mortality. Counts of all-cause deaths from May 1-31, 2010 were compared with the mean of counts from temporally matched periods in May 2009 and 2011 to calculate excess mortality. Other analyses included a 7-day moving average, mortality rate ratio analysis, and relationship between daily maximum temperature and daily all-cause death counts over the entire year of 2010, using month-wise correlations.
The May 2010 heat wave was associated with significant excess all-cause mortality. 4,462 all-cause deaths occurred, comprising an excess of 1,344 all-cause deaths, an estimated 43.1% increase when compared to the reference period (3,118 deaths). In monthly pair-wise comparisons for 2010, we found high correlations between mortality and daily maximum temperature during the locally hottest "summer" months of April (r = 0.69, p<0.001), May (r = 0.77, p<0.001), and June (r = 0.39, p<0.05). During a period of more intense heat (May 19-25, 2010), mortality rate ratios were 1.76 [95% CI 1.67-1.83, p<0.001] and 2.12 [95% CI 2.03-2.21] applying reference periods (May 12-18, 2010) from various years.
The May 2010 heat wave in Ahmedabad, Gujarat, India had a substantial effect on all-cause excess mortality, even in this city where hot temperatures prevail through much of April-June.
最近，在包括北美和欧洲在内的发达国家，已经有与显著死亡率相关的极端高温时段的记录。然而，来自发展中国家或南亚特定城市的研究报告要少得多。2010年5月，印度艾哈迈达巴德遭遇热浪，气温高达46.8°C，死亡率明显上升。本研究的目的是描述热浪的影响并评估相关的超额死亡率。
我们对印度古吉拉特邦艾哈迈达巴德2010年5月热浪期间的全因死亡率进行了分析，以确定极端高温是否会导致超额死亡率。将2010年5月1日至31日的全因死亡人数与2009年和2011年5月时间匹配时段的死亡人数平均值进行比较，以计算超额死亡率。其他分析包括7天移动平均值、死亡率比分析，以及使用逐月相关性分析2010年全年每日最高气温与每日全因死亡人数之间的关系。
2010年5月的热浪与显著的全因超额死亡率相关。共发生4462例全因死亡，其中超额全因死亡1344例，与参考期（3118例死亡）相比，估计增加了43.1%。在2010年的逐月配对比较中，我们发现，在当地最热的“夏季”月份4月（r = 0.69，p<0.001）、5月（r = 0.77，p<0.001）和6月（r = 0.39，p<0.05），死亡率与每日最高气温之间存在高度相关性。在一段更强烈的高温期（2010年5月19日至25日），采用不同年份的参考期（2010年5月12日至18日），死亡率比分别为1.76 [95%可信区间1.67 - 1.83，p<0.001]和2.12 [95%可信区间2.03 - 2.21]。
印度古吉拉特邦艾哈迈达巴德2010年5月的热浪对全因超额死亡率产生了重大影响，即使在这个4月至6月大部分时间气温都很高的城市也是如此。
