Table 1.
Descriptive statistics of daily number of asthma admissions, meteorological factors and air pollutants in Shijiazhuang, during 2013–2016
| mean | sd | min | 25%Q | 50%Q | 75%Q | max | |
|---|---|---|---|---|---|---|---|
| heating season(604 d) | |||||||
| daily admissions (n = 1815)* | 3.00 | 0.99 | 0.00 | 2.00 | 3.00 | 4.00 | 7.00 |
| PM2.5(μg/m3)* | 162.22 | 120.63 | 9.00 | 71.00 | 128.00 | 212.14 | 750.50 |
| PM10(μg/m3)* | 263.16 | 164.32 | 18.00 | 142.75 | 227.00 | 349.50 | 926.00 |
| CO(mg/m3)* | 2.49 | 1.75 | 0.20 | 1.20 | 2.00 | 3.30 | 12.60 |
| NO2(μg/m3)* | 73.29 | 31.50 | 13.00 | 50.96 | 68.50 | 93.00 | 188.00 |
| SO2(μg/m3)* | 106.49 | 74.65 | 4.00 | 52.00 | 85.00 | 137.14 | 515.43 |
| O3(μg/m3)* | 39.79 | 27.83 | 2.00 | 16.00 | 34.17 | 57.00 | 183.00 |
| daily mean temperature (°C)* | 3.66 | 5.53 | −9.40 | −0.50 | 2.90 | 7.20 | 20.00 |
| daily mean air pressure (kPa)* | 51.52 | 21.30 | 12.00 | 34.00 | 50.00 | 68.00 | 97.00 |
| non-heating season(856 d) | |||||||
| daily admissions (n = 2230) | 2.61 | 0.82 | 0.00 | 2.00 | 3.00 | 3.00 | 5.00 |
| PM2.5(μg/m3) | 84.13 | 60.00 | 6.00 | 40.00 | 71.07 | 109.00 | 421.57 |
| PM10(μg/m3) | 164.54 | 104.23 | 17.00 | 85.63 | 138.00 | 213.25 | 679.86 |
| CO(mg/m3) | 1.00 | 0.50 | 0.10 | 0.70 | 0.90 | 1.21 | 3.91 |
| NO2(μg/m3) | 46.00 | 20.60 | 9.00 | 31.00 | 43.71 | 58.08 | 132.00 |
| SO2(μg/m3) | 34.19 | 25.97 | 3.00 | 16.00 | 28.00 | 43.00 | 178.73 |
| O3(μg/m3) | 109.54 | 50.20 | 4.00 | 76.00 | 105.00 | 147.00 | 262.00 |
| daily mean temperature (°C) | 22.25 | 5.72 | 3.10 | 18.60 | 23.30 | 26.80 | 35.50 |
| daily mean air pressure (kPa) | 61.42 | 18.38 | 12.00 | 48.00 | 63.00 | 75.00 | 99.00 |
*:P < 0.001 compared with non-heating season using Wilcoxon test
sd standard deviation, Q quantile