Table 2.

Crude and adjusted odds ratios (95% confidence interval, CI) of meteorological conditions and air pollution parameters (mean of 3 years [1095 days] before index date) for thyroid cancer.

Characteristics		Odds ratio for thyroid cancer (95% CI)
		Crude†	P value	Model 1†,‡	P value	Model 2†,§	P value
Mean temperature (°C)		1.05 (1.02–1.08)	0.002*	1.04 (1.01–1.07)	0.020*
Highest temperature (°C)		1.04 (1.01–1.07)	0.008*	1.03 (1.00–1.06)	0.059
Lowest temperature (°C)		1.04 (1.01–1.07)	0.003*	1.03 (1.00–1.06)	0.026*
Temperature range (°C)		0.98 (0.95–1.02)	0.355	0.99 (0.95–1.02)	0.430
Relative humidity (%)		1.01 (1.00–1.02)	0.240	1.00 (0.99–1.01)	0.676	1.01 (1.00–1.03)	0.023*
Ambient atmospheric pressure (hPa)		1.02 (1.01–1.03)	< 0.001*	1.02 (1.01–1.03)	< 0.001*	1.02 (1.01–1.03)	< 0.001*
Sunshine duration (hr)		1.18 (1.07–1.30)	0.001*	1.21 (1.09–1.34)	< 0.001*	1.17 (1.04–1.31)	0.007*
Rainfall (mm)		1.07 (1.02–1.12)	0.003*	1.09 (1.04–1.14)	< 0.001*
SO2 (0.01 ppm)		0.71 (0.50–1.00)	0.052	0.69 (0.48–0.98)	0.040*
NO2 (0.01 ppm)		0.98 (0.94–1.03)	0.388	1.00 (0.96–1.05)	0.924	1.33 (1.24–1.43)	< 0.001*
O3 (0.01 ppm)		1.19 (1.10–1.30)	< 0.001*	1.17 (1.07–1.28)	< 0.001*
CO (ppm)		0.42 (0.28–0.63)	< 0.001*	0.42 (0.27–0.64)	< 0.001*
PM10 (10 μg/m3)		0.81 (0.77–0.85)	< 0.001*	0.81 (0.77–0.85)	< 0.001*	0.64 (0.60–0.69)	< 0.001*

CCI Charlson comorbidity index; DBP diastolic blood pressure; SBP systolic blood pressure.

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

^† Stratified model for age group, sex, income, and region of residence.

^‡Model 1 was adjusted for total cholesterol, SBP, DBP, fasting blood glucose, obesity, smoking status, alcohol consumption, and CCI score.

^§Model 2 was adjusted for total cholesterol, SBP, DBP, fasting blood glucose, obesity, smoking status, alcohol consumption, CCI score, temperature range, relative humidity, ambient atmospheric pressure, sunshine duration, SO₂, NO₂, O₃, CO, and PM₁₀ using the forward selection method.