Table 2.

Crude and adjusted odd ratios (95% confidence interval) of the meteorological and pollution matter (mean of 30 days before the index date) for ischemic heart disease.

Characteristics	Odds ratio for ischemic heart disease (95% CI)
	Crudea	P-value	Adjusteda,b	P-value	Finala,c	P-value
Mean temperature for 30 days (°C)	1.00 (1.00–1.01)	0.864	0.90 (0.65–1.24)	0.506
Highest temperature for 30 days (°C)	1.00 (1.00–1.01)	0.935	1.04 (0.89–1.21)	0.660
Lowest temperature for 30 days (°C)	1.00 (1.00–1.01)	0.798	1.09 (0.92–1.29)	0.334
Relative humidity for 30 days (%)	1.00 (0.99–1.00)	0.271	0.99 (0.98–1.00)	0.045*
Ambient atmospheric pressure for 30 days (hPa)	1.00 (0.99–1.01)	0.697	1.00 (0.99–1.01)	0.923
SO2 for 30 days (0.01 ppm)	1.36 (1.07–1.75)	0.014*	1.74 (1.18–2.56)	0.005*	1.36 (1.06–1.75)	0.015*
NO2 for 30 days (0.1 ppm)	0.59 (0.31–1.11)	0.099	0.40 (0.15–1.07)	0.066
O3 for 30 days (0.01 ppm)	1.04 (0.98–1.10)	0.227	0.98 (0.89–1.09)	0.727
CO for 30 days (ppm)	1.01 (0.77–1.32)	0.939	1.02 (0.61–1.73)	0.935
PM10 for 30 days (10 μg/m3)	1.00 (0.97–1.04)	0.859	1.01 (0.96–1.07)	0.593

*Conditional logistic regression model, Significance at P < 0.05.

^aStratified model for age, sex, income, and region of residence.

^bAdjusted model was adjusted for obesity, smoking status (current smoker compared to nonsmoker or past smoker), frequency of alcohol consumption (≥ 1 time a week compared to < 1 time a week), CCI score, mean temperature, highest temperature, lowest temperature, relative humidity, atmospheric pressure, SO₂, NO₂, O₃, CO, and PM₁₀.

^cFinal model was adjusted for obesity, smoking status (current smoker compared to nonsmoker or past smoker), frequency of alcohol consumption (≥ 1 time a week compared to < 1 time a week), CCI score, relative humidity, SO₂, NO₂, O₃, CO, and PM₁₀ using the backward selection method.