Table 3.

Conditional logistic regression analyses for the association between ALS and exposure to air pollution.

Air pollutants	Unadjusted modela OR (95% CI)	Trend p-Value	Model 1b OR (95% CI)	Trend p-Value	Model 2c OR (95% CI)	Trend p-Value
$\mathrm{P}{\mathrm{M}}_{10}$ ($\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$)
Q1 ($\le 30.9$)	Reference		Reference		Reference
Q2 ($>30.9–\le 31.6$)	0.79 (0.61, 1.02)		0.77 (0.59, 1.00)		0.75 (0.57, 0.98)
Q3 ($>31.6–\le 32.2$)	0.83 (0.63, 1.10)	0.004	0.83 (0.62, 1.10)	0.006	0.77 (0.57, 1.05)	0.19
Q4 ($>32.2$)	1.29 (0.98, 1.70)		1.29 (0.97, 1.72)		1.12 (0.79, 1.57)
$\mathrm{P}{\mathrm{M}}_{\text{coarse}}$ ($\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$)
Q1 ($\le 9.9$)	Reference		Reference		Reference
Q2 ($>9.9–\le 10.2$)	0.83 (0.65, 1.06)		0.82 (0.64, 1.05)		0.77 (0.60, 1.00)
Q3 ($>10.2–\le 10.5$)	0.97 (0.76, 1.24)	0.003	0.95 (0.74, 1.24)	0.01	0.84 (0.64, 1.11)	0.24
Q4 ($>10.5$)	1.28 (0.99, 1.64)		1.24 (0.95, 1.61)		1.04 (0.77, 1.41)
$\mathrm{P}{\mathrm{M}}_{2.5}$ ($\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$)
Q1 ($\le 20.7$)	Reference		Reference		Reference
Q2 ($>20.7–\le 21.3$)	0.99 (0.76, 1.28)		0.98 (0.75, 1.28)		0.92 (0.70, 1.21)
Q3 ($>21.3–\le 21.7$)	0.82 (0.61, 1.11)	0.08	0.85 (0.62, 1.16)	0.10	0.80 (0.59, 1.09)	0.24
Q4 ($>21.7$)	1.37 (0.99, 1.89)		1.35 (0.97, 1.88)		1.24 (0.89, 1.73)
$\mathrm{P}{\mathrm{M}}_{2.5}$ absorbance (${10}^{-5}/\mathrm{m}$)
Q1 ($\le 1.29$)	Reference		Reference		Reference
Q2 ($>1.29–\le 1.38$)	1.13 (0.89, 1.45)		1.14 (0.88, 1.47)		1.11 (0.85, 1.44)
Q3 ($>1.39–\le 1.49$)	1.06 (0.81, 1.37)	$<0.001$	1.12 (0.86, 1.47)	$<0.001$	1.09 (0.81, 1.47)	0.002
Q4 ($>1.49$)	1.65 (1.28, 2.14)		1.67 (1.27, 2.18)		1.57 (1.14, 2.17)
$\mathrm{N}{\mathrm{O}}_2$ ($\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$)
Q1 ($\le 22.5$)	Reference		Reference		Reference
Q2 ($>22.5–\le 25.8$)	1.33 (1.05, 1.61)		1.38 (1.09, 1.76)		1.29 (1.01, 1.66)
Q3 ($>25.8–\le 29.0$)	1.17 (0.91, 1.51)	$<0.001$	1.25 (0.97, 1.63)	$<0.001$	1.15 (0.85, 1.55)	0.03
Q4 ($>29.0$)	1.71 (1.32, 2.23)		1.74 (1.32, 2.30)		1.55 (1.08, 2.21)
$\mathrm{N}{\mathrm{O}}_{\mathrm{x}}$ ($\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3$)
Q1 ($\le 38.2$)	Reference		Reference		Reference
Q2 ($>38.2–\le 42.2$)	0.97 (0.77, 1.22)		0.98 (0.78, 1.24)		0.91 (0.71, 1.15)
Q3 ($>42.2–\le 47.3$)	1.07 (0.85, 1.86)	0.001	1.12 (0.87, 1.43)	0.004	0.99 (0.76, 1.30)	0.14
Q4 ($>47.3$)	1.40 (1.10, 1.78)		1.38 (1.07, 1.77)		1.17 (0.87, 1.57)

Note: Conditional logistic regression analysis with the exposure divided into quartiles (Q) based on the levels in controls. Three different (multivariate) models are shown.

^aThe unadjusted model shows unadjusted odds ratios (ORs).

^bModel 1 was adjusted for gender, age, educational level, current smoking status, current alcohol consumption, body mass index (BMI), and area-level socioeconomic status (SES).

^cModel 2 was adjusted as in model 1, but also for urbanization degree.