The acute effect of temperature on asthma morbidity in Bangladesh is not well understood. As climate varies extensively in different parts of the world, the relation between temperature and asthma might also differ. We investigated the association between temperature and asthma-related hospital visits in the tropical city of Dhaka. We analyzed information from a total of 5989 asthma patients who received ambulatory care in the form of nebulized medication at the National Asthma Center in Mohakhali, Dhaka from February to November 2013. A time-stratified case-crossover study was conducted to estimate the effect of daily temperature, with consideration of delayed effects and possible confounders such as relative humidity and political strikes. An inverse association was observed between temperature and the number of hospital visits. The effect was delayed for approximately a week. A degree centigrade decrease in mean temperature (averaged across lags 0-6) was associated with an increase of approximately 4.5% (95% CI 1.5, 7.5) in all asthma visits. The association was evident in adult males but marginal in elderly males. A positive association (lag 0) was observed among adult females, whereas no association was observed among children. Strikes significantly modified the effect among the elderly. Findings suggest temperature declines affect asthma outcomes in a warm climate, and this effect can be delayed and vary by sex and age group.

中文翻译：

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环境温度对孟加拉国达卡一个热带城市日常雾化哮喘医院就诊的影响

温度对孟加拉国哮喘发病率的急性影响尚不清楚。由于世界各地气候变化很大，温度与哮喘之间的关系也可能不同。我们调查了热带城市达卡的温度与哮喘相关医院就诊之间的关联。我们分析了2013年2月至2013年11月在达卡莫哈卡利国家哮喘中心接受雾化药物形式门诊治疗的5989名哮喘患者的信息。进行了时间分层的病例交叉研究以评估每日温度，考虑到延迟影响和可能的混杂因素，例如相对湿度和政治罢工。观察到温度与就诊次数之间呈负相关。效果被延迟了大约一周。在所有哮喘访视中，平均温度下降1摄氏度（平均滞后0-6）与大约4.5％的升高（95％CI 1.5，7.5）相关。这种关联在成年男性中很明显，而在老年男性中则很小。在成年女性中观察到正关联（滞后0），而在儿童中未观察到关联。罢工极大地改变了老年人的效果。研究结果表明，温度下降会影响温暖气候下的哮喘结局，并且这种影响可能会延迟并且因性别和年龄组而异。这种关联在成年男性中很明显，而在老年男性中则很小。在成年女性中观察到正关联（滞后0），而在儿童中未观察到关联。罢工极大地改变了老年人的效果。研究结果表明，温度下降会影响温暖气候下的哮喘结局，并且这种影响可能会延迟并且因性别和年龄组而异。这种关联在成年男性中很明显，而在老年男性中则很小。在成年女性中观察到正关联（滞后0），而在儿童中未观察到关联。罢工极大地改变了老年人的效果。研究结果表明，温度下降会影响温暖气候下的哮喘结局，并且这种影响可能会延迟并且因性别和年龄组而异。