Assessment of Effects of Air Pollution on Daily Outpatient Visits using the Air Quality Index

Background

The air quality index (AQI) is widely used to characterize the quality of ambient air. Chinese citiesofficially report the AQI on a daily basis. To assess the possible effects of air pollution on daily outpatientvisits, 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 ofDatong City, China. The collection period was between 5 April and 30 June, 2012. Daily AQI data and meteorologicalinformation 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 differencewas observed in temperature or relative humidity between index days and comparison days. The outpatient countsfor pediatrics were significantly higher on index days than on comparison days, and no significant difference wasnoted in other clinical departments. The outpatient counts for pediatrics positively correlated with the AQI level,and no correlation was noted in other clinical departments.

Conclusion

The present study assessed the association between daily outpatient visits and air pollution using AQI. The resultsobtained suggest that air pollution could increase the outpatient count for pediatrics.