Canadian Respiratory Journal

Research Article

Relationship between Air Pollution and Hospital Admissions for Chronic Obstructive Pulmonary Disease in Changchun, China: A Season-Stratified Case-Cross Study

Table 2

Hospital admissions for COPD patients and concentrations of air pollutants change on different lag days in different seasons.


Season	Lag days	PM_2.5	PM₁₀	SO₂	NO₂	CO	O₃
Season	Lag days	OR (95%CI)	OR (95%CI)	OR (95%CI)	OR (95%CI)	OR (95%CI)	OR (95%CI)

Spring	0	0.997 (0.992–1.001)	0.999 (0.998–1.001)	0.998 (0.986–1.011)	0.993 (0.984–1.002)	0.607 (0.376–0.981)	1.002 (0.997–1.006)
	1	1.002 (0.997–1.007)	1.000 (0.999–1.002)	1.000 (0.987–1.014)	1.003 (0.993–1.012)	1.393 (0.813–2.386)	1.001 (0.996–1.007)
	2	0.998 (0.993–1.003)	1.000 (0.998–1.001)	0.991 (0.977–1.005)	0.995 (0.985–1.005)	0.786 (0.434–1.425)	0.999 (0.994–1.005)
	3	1.001 (0.996–1.006)	1.001 (0.999–1.002)	0.999 (0.986–1.013)	1.000 (0.990–1.010)	1.042 (0.587–1.851)	1.003 (0.997–1.008)
	4	1.002 (0.997–1.007)	1.000 (0.998–1.002)	1.004 (0.993–1.016)	1.007 (0.998–1.015)	1.291 (0.804–2.072)	1.000 (0.995–1.004)

Summer	0	0.996 (0.998–1.004)	0.999 (0.994–1.003)	1.013 (0.961–1.068)	0.998 (0.986–1.011)	0.832 (0.388–1.782)	0.997 (0.992–1.002)
	1	1.002 (0.992–1.011)	0.999 (0.994–1.004)	0.965 (0.907–1.026)	0.996 (0.981–1.011)	1.089 (0.446–2.658)	1.001 (0.994–1.008)
	2	0.994 (0.986–1.003)	0.999 (0.995–1.004)	1.002 (0.942–1.066)	1.000 (0.985–1.016)	0.860 (0.346–2.139)	0.996 (0.989–1.003)
	3	1.007 (1.000–1.015)	1.003 (0.998–1.008)	1.015 (0.957–1.076)	1.000 (0.986–1.015)	1.531 (0.612–3.829)	1.002 (0.996–1.009)
	4	0.990 (0.982–0.999)	0.996 (0.992–1.000)	0.961 (0.912–1.013)	0.997 (0.985–1.010)	0.574 (0.259–1.272)	0.997 (0.992–1.002)

Autumn	0	1.000 (0.998–1.002)	1.000 (0.998–1.002)	0.999 (0.988–1.010)	0.999 (0.992–1.007)	0.985 (0.742–1.307)	0.997 (0.991–1.003)
	1	1.000 (0.997–1.002)	1.000 (0.998–1.002)	0.997 (0.982–1.012)	0.998 (0.990–1.006)	0.958 (0.690–1.330)	1.001 (0.994–1.007)
	2	1.000 (0.998–1.002)	1.000 (0.998–1.002)	1.006 (0.991–1.021)	1.000 (0.991–1.009)	0.948 (0.682–1.316)	1.000 (0.993–1.007)
	3	1.002 (0.999–1.004)	1.001 (0.999–1.003)	1.000 (0.986–1.015)	1.004 (0.996–1.012)	1.246 (0.894–1.737)	0.999 (0.992–1.005)
	4	0.999 (0.997–1.002)	1.000 (0.998–1.001)	1.004 (0.992–1.016)	1.000 (0.993–1.007)	1.005 (0.780–1.294)	1.000 (0.994–1.005)

Winter	0	1.000 (0.998–1.003)	1.000 (0.998–1.002)	1.001 (0.995–1.006)	1.002 (0.994–1.009)	0.945 (0.772–1.237)	1.001 (0.991–1.011)
	1	0.999 (0.997–1.002)	1.000 (0.998–1.002)	1.001 (0.994–1.008)	0.998 (0.988–1.008)	1.022 (0.748–1.396)	1.007 (0.995–1.020)
	2	1.002 (0.999–1.005)	1.001 (0.998–1.003)	1.000 (0.993–1.007)	1.009 (0.998–1.020)	1.279 (0.909–1.801)	0.991 (0.977–1.005)
	3	0.998 (0.994–1.001)	0.999 (0.996–1.001)	0.998 (0.991–1.004)	0.992 (0.981–1.002)	0.783 (0.559–1.097)	1.005 (0.991–1.019)
	4	1.000 (0.997–1.003)	1.000 (0.998–1.002)	1.000 (0.994–1.005)	0.999 (0.991–1.007)	0.969 (0.747–1.257)	1.003 (0.992–1.014)