Relationship of meteorological factors and air pollutants with medical care utilization for gastroesophageal reflux disease in urban area

Table 1 Summary statistics of the relationship of gastroesophageal reflux disease-related medical utilizations with meteorological factors and air pollutants

	mean ± SD	Quantiles
		Min	25%	50%	75%	Max
Sex, n (%)
Male	81687 (40.8)
Female	118313 (59.2)
Age group, yr, n (%)
< 10	341 (0.17)
10-19	2402 (1.20)
20-29	6863 (3.43)
30-39	12477 (6.24)
40-49	23564 (11.78)
50-59	46228 (23.11)
60-69	49190 (24.60)
70-79	43077 (21.54)
≥ 80	15858 (7.93)
Meteorological factors
Average temperature (°C)	13.8 ± 9.8	-13.7	5.4	15.2	22.4	33.1
High temperature (°C)	18.4 ± 10.0	-10.7	10.1	20.2	27.0	38.8
Low temperature (°C)	10.0 ± 10.0	-17.1	1.0	10.9	18.9	28.8
Diurnal temperature Range (°C)	8.4 ± 3.3	0.0	6.3	8.3	10.5	23.4
Vapor pressure (hPa)	12.2 ± 8.5	0.0	4.7	10.4	18.7	38.3
Solar radiation (MJ/m2)	12.6 ± 7.3	0.0	7.2	12.2	18.3	33.0
Sunshine duration (hr)	12.0 ± 2.3	9.7	10.5	12.2	13.9	14.8
Wind speed (m/s)	2.5 ± 1.1	0.0	1.8	2.4	3.1	10.1
Daily rain (mm)	3.2 ± 12.5	0.0	0.0	0.0	0.3	310.0
Dew point temperature (°C)	6.3 ± 11.6	-25.9	-3.0	7.3	16.4	28.2
Humidity (%)	62.1 ± 18.6	0.0	49.9	63.3	75.5	100.0
Daily snow (cm)	0.1 ± 0.9	0.0	0.0	0.0	0.0	29.2
Cloud (1/10)	4.5 ± 3.2	0.0	1.6	4.5	7.4	10.0
Air pollutants
PM2.5 (μg/m3)	15.9 ± 16.1	0.0	3.0	14.0	26.0	99.0
PM10 (μg/m3)	46.6 ± 25.9	0.0	31.2	42.6	57.0	1025.4
1O3 (ppb)	23.7 ± 11.6	0.0	15.4	23.0	31.3	83.8
NO2 (ppb)	28.2 ± 12.6	0.0	18.9	26.4	35.5	94.9
SO2 (ppb)	5.1 ± 2.1	0.0	3.8	4.9	6.2	25.8
CO (ppm)	0.5 ± 0.2	0.0	0.4	0.5	0.6	2.2

¹An 8 h maximum was used for O₃. SD: Standard deviation; PM_2.5: Particulate matter with a diameter ≤ 2.5 µm; PM₁₀: Particulate matter with a diameter ≤ 10 µm; NO₂: Nitrogen dioxide; SO₂: Sulphur dioxide; CO: Carbon monoxide; ppb: Parts-per-billion; ppm: Parts-per-million.