Effect of Ambient Temperature on Daily Nebulized Asthma Hospital Visits in a Tropical City of Dhaka, Bangladesh.

Ayesha Ferdosi Kabir,Taiichi Hayashi,Chiho Watanabe,Shinya Yasumoto,Chris Fook Sheng Ng

doi:10.3390/ijerph18030890

Abstract

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.

Highlights

Asthma is a chronic respiratory disease affecting an estimated 300 million people worldwide, with approximately 250,000 annual deaths reported [1,2,3]
Data on daily hospital visits were collected from the National Asthma Centre (NAC)
NAC is a specialized division of the National Institute of Disease and Chest Hospital (NIDCH) for treating respiratory diseases

Summary

Introduction

Asthma is a chronic respiratory disease affecting an estimated 300 million people worldwide, with approximately 250,000 annual deaths reported [1,2,3]. The prevalence of the disease has been rising around the world [4] and this increasing trend is discernible in developing countries undergoing urbanization [5]. In Bangladesh, a national study conducted in 1999 reported a prevalence of 6.9% based on self-reported data; the study estimated that 7 million people, 4 million of whom were children, suffered from asthma-related symptoms [6]. The disease poses as a serious public health problem in the country [7,8]. Very little is known about its etiology and risk factors in Bangladesh

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Conclusion