Ambient Particulate Matter and Emergency Department Visit for Chronic Obstructive Pulmonary Disease

ABSTRACT

PURPOSE: This study aimed to explore the association between increased level of ambient particulate matter and emergency room visits for chronic obstructive pulmonary disease (COPD) exacerbations. METHODS: A retrospective study was conducted. We enrolled patients who lived in Seoul, Korea and were diagnosed with COPD in the emergency room between January 2012 and December 2014. Meteorological factors [daily highest temperature, lowest temperature, mean temperature, diurnal temperature, rainfall, relative humidity, amount of sunshine and particulate matter less than 10 µm (PM 10)] between December 2011 and December 2014 in Seoul were acquired from the Korea Meteorological Administration. We used a multiple Poisson regression model with daily patient's number of COPD as a response variable and meteorological factors as explanatory variable. Variable selection was done via an Elastic net. RESULTS: There was a total of 1,179 emergency visits for acute exacerbations of COPD patients. PM10 (before 4, 10, 11, 15, 16, 17, 22, 24, 27, 28 day), rainfall (before 1, 6, 8, 16, 18 day), relative humidity (before 2, 8), and daily temperature difference (5, 10, 15 day) had a relationship and a lag effect with COPD exacerbations. CONCLUSION: This study showed that an increased concentration of PM10 was associated with COPD exacerbations. A future study that reinforces the limitation of this study is necessary to get a helpful index for an adequate response of medical institution and efficient placement of medical personnel.