A Time Series Analysis of Associations between Climate Change and Heat Related Illnesses and Development of Heat Health Warning System in Thailand

摘要

A heat health warning system (HHWS) is not set up in Thailand and there is an increasing number of heat - related illnesses (HRI) yearly. As a result of this, the aims of this study is to implementing a suitable threshold level for HHWS in Thailand, which could be different from NOAA guideline. Method: This study were divided into 3 phases with mixed method approach. In phase 1, Daily HRI of hospital admissions from the ICD10 database with diagnosis T67 (Effects of heat and light) were collected between January 2010 to December 2014.Daily temperature and humidity from the same period were obtained. Heat index (HI) was calculated according to the Steadman equation. Time series and Poisson regression analysis were used to find out the relationship between HRI and heat index controlling for day of the week and holiday indicator, for lag times of 1- 7 days. Relative risk (RR) and 95% confidence interval were calculated in each increment of inter-quartile range (IQR) change of HI by each region of Thailand. Next, e-Delphi technique was applied to elicit the opinions of 16 experts involved in climate research. Lastly, to verify the phase 2 findings, a focus group discussion with key stakeholders and policy makers was planned. Results: RR increase 33% (95%CI: 29%-38%) when HI increase per IQR (7.3) in Thailand. The relative risks at 75th percentile of HI at lag 0 of Southern, Northern, Central and Northeast regions were 5.56, 21.76, 79.59, and 39.75, respectively. Threshold level for HHWS are divided to 3 levels, which are pre-alert, higher alert and highest alert level. Based on expert's opinions, the pre- alert level is the level of HI below 75th percentile, the higher level is the level of HI from 75th percentile to 90th percentile. Lastly, the highest level is start from 90th percentile of HI. Conclusion: The level of HI has a positive association with HRI and the suitable warning threshold level for HHWS of Thailand are different from United State of America.