Table 3 Time-lagged associations between PM_2.5 exposure groups and asthma exacerbation, with the 0–15 µg/m³ group as the reference

OR (95% CI)

P-value

OR (95% CI)

P-value

OR (95% CI)

P-value

Lag0

1.01 (0.96, 1.06)

0.600

1.06 (0.98, 1.14)

0.176

1.54 (1.17, 2.03)

0.002*

Lag1

1.03 (0.98, 1.08)

0.308

0.96 (0.89, 1.04)

0.313

1.14 (0.86, 1.50)

0.370

Lag2

1.01 (0.96, 1.06)

0.675

0.99 (0.91, 1.07)

0.735

1.41 (1.07, 1.85)

0.014*

Lag3

0.97 (0.92, 1.02)

0.218

0.92 (0.85, 0.99)

0.036*

1.12 (0.84, 1.50)

0.447

Lag4

0.99 (0.94, 1.04)

0.696

0.94 (0.87, 1.02)

0.158

0.98 (0.73, 1.33)

0.916

Lag5

0.96 (0.92, 1.01)

0.149

0.94 (0.87, 1.02)

0.137

0.88 (0.66, 1.17)

0.365

Lag6

0.97 (0.93, 1.02)

0.280

0.92 (0.85, 0.99)

0.037*

0.93 (0.70, 1.23)

0.608

Lag7

0.99 (0.95, 1.04)

0.835

0.91 (0.84, 0.99)

0.022*

0.59 (0.43, 0.81)

0.001*

Lag01

1.03 (0.98, 1.09)

0.206

1.04 (0.95, 1.13)

0.410

1.59 (1.17, 2.17)

0.003*

Lag02

1.01 (0.96, 1.07)

0.612

1.03 (0.94, 1.12)

0.521

1.64 (1.16, 2.30)

0.005*

Lag03

1.02 (0.97, 1.07)

0.506

1.01 (0.92, 1.10)

0.819

1.51 (1.07, 2.13)

0.019*

Lag04

0.99 (0.94, 1.04)

0.654

0.98 (0.89, 1.07)

0.603

1.28 (0.92, 1.78)

0.142

Lag05

0.97 (0.92, 1.02)

0.287

0.96 (0.87, 1.05)

0.359

0.97 (0.67, 1.41)

0.872

Lag06

0.96 (0.91, 1.02)

0.186

0.92 (0.83, 1.01)

0.081

0.72 (0.48, 1.08)

0.112

Lag07

0.96 (0.91, 1.01)

0.142

0.90 (0.82, 1.00)

0.043*

0.82 (0.53, 1.25)

0.349