A Time Series Study on the Air Quality Index and Outpatient Visits for Respiratory Diseases in Suzhou Industrial Park in 2016

Objectives To explore the relationship between the air quality index (AQI) and daily outpatient visits for respiratory diseases by using a GAM model.

Methods Daily outpatient visits for respiratory diseases in 43 community health service stations and 5 community health service centers in Suzhou Industrial Park in January 1 to December 31, 2016, meteorological data and major atmospheric pollutants (PM_2.5, PM₁₀, SO₂, NO₂, CO, O_3-1, O_3-8) in Suzhou Industrial Park were collected; AQI was calculated by using the concentration of major atmospheric pollutants; and the relationship between AQI and the outpatient visits for respiratory diseases was analyzed by using a semiparametric generalized additive model (GAM).

Results There was a certain lag effect of air quality index (AQI) on daily outpatient visits for respiratory diseases, and the average of AQI 4 days before (lag04) had the most significant effect on the number of outpatients with respiratory diseases. Under this optimal hysteresis condition, the number of outpatients for respiratory diseases per day increased by 6.7% (RR=1.067, 95% CI:1.061 to 1.074) for each increase of interquartile interval of AQI.

Conclusions The increase of AQI would lead to an increase of outpatient visits for respiratory diseases and would cause some harm to the health of human respiratory system.