title: Assessment of Effects of Air Pollution on Daily Outpatient Visits using the Air Quality Index.
abstract: BACKGROUND
  The air quality index (AQI) is widely used to characterize the quality of ambient air. Chinese cities officially report the AQI on a daily basis. To assess the possible effects of air pollution on daily outpatient visits, we examined the association between AQI and the daily outpatient count.
  
  
  METHODS
  Daily data on outpatient visits to each clinical department were collected from the Z county hospital of Datong City, China. The collection period was between 5 April and 30 June, 2012. Daily AQI data and meteorological information were simultaneously recorded. We compared outpatient counts between the index days and comparison days, and calculated Pearson's product moment correlation coefficient between outpatient counts and AQI levels.
  
  
  RESULTS
  The average AQI level for index days was significantly higher than that for comparison days. No significant difference was observed in temperature or relative humidity between index days and comparison days. The outpatient counts for pediatrics were significantly higher on index days than on comparison days, and no significant difference was noted in other clinical departments. The outpatient counts for pediatrics positively correlated with the AQI level, and no correlation was noted in other clinical departments.
  
  
  CONCLUSIONS
  The present study assessed the association between daily outpatient visits and air pollution using AQI. The results obtained suggest that air pollution could increase the outpatient count for pediatrics.
authors.affiliation: Division of Health Administration and Promotion, Department of Social Medicine, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Haosheng
authors.initials: H
authors.lastname: Mu
authors.affiliation: †Division of Surgical Oncology, Department of Surgery, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Otani
authors.affiliation: ‡Cancer Center, Tottori University Hospital, Yonago 683-8504, Japan.
authors.forename: Mikizo
authors.initials: M
authors.lastname: Okamoto
authors.affiliation: Division of Health Administration and Promotion, Department of Social Medicine, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Yae
authors.initials: Y
authors.lastname: Yokoyama
authors.affiliation: §Department of Nursing Care Environment and Mental Health, School of Health Science, Tottori University Faculty of Medicine, Yonago 683-8503, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Tokushima
authors.affiliation: Division of Health Administration and Promotion, Department of Social Medicine, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Onishi
authors.affiliation: Division of Health Administration and Promotion, Department of Social Medicine, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Takenobu
authors.initials: T
authors.lastname: Hosoda
authors.affiliation: Division of Health Administration and Promotion, Department of Social Medicine, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8504, Japan.
authors.forename: Youichi
authors.initials: Y
authors.lastname: Kurozawa
keywords: air pollution; air quality index; daily outpatient visit