Table 3.

Results of crude and adjusted negative binomial regression and of the effect of pollutants and climate factors on respiratory hospital admissions (ratio of increase in hospital admissions in day per unit of increase in pollutants and climate factors daily average) in the epidemic periods.

Variables	Crude IRR and 95% CI	P	Adjusted IRR and 95% CI	P
O3 (ppm)	1.000 (0.995–1.005)	0.982	1.002 (0.998–1.007)	0.345
PM10 (µ g/m3)	1.000 (0.999–1.000)	0.293	1.000 (0.999–1.001)	0.506
NO (ppm)	1.007 (1.001–1.012)	0.013	1.008 (1.001–1.016)	0.037
NO2 (ppm)	0.996 (0.989–1.002)	0.201	0.993 (0.983–1.003)	0.172
NOx (ppm)	1.002 (0.999–1.006)	0.191	1.001 (0.997–1.006)	0.503
CO (ppm)	1.000 (1.000–1.000)	0.424	1.000 (1.000–1.000)	0.618
SO2 (ppm)	1.009 (0.999–1.020)	0.085	1.014 (1.000–1.028)	0.044
Temperature (°C)	0.935 (0.867–1.008)	0.078	0.163 (0.076–0.351)	<0.001
Relative humidity (%)	1.029 (0.995–1.064)	0.095	1.418 (1.041–1.932)	0.027
Total rainfall (mm)	1.056 (1.012–1.103)	0.012	1.154 (0.963–1.384)	0.120
Total evaporation (mm)	0.998 (0.994–1.001)	0.195	1.130 (1.072–1.191)	<0.001
Wind speed (m/s)	1.100 (0.918–1.318)	0.303	0.461 (0.233–0.915)	0.027