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Table 4 Associations between air pollutants and primary care visits at night due to asthma attack (multiple pollutant model)

From: Association between PM2.5 and primary care visits due to asthma attack in Japan: relation to Beijing’s air pollution episode in January 2013

Air pollutants

Unit increment

Concentration on the day of the PCV

Concentration on the day before the PCV

3-day mean concentration before the PCV

OR

95 % CI

OR

95 % CI

OR

95 % CI

PM2.5

10 μg/m3

0.994

0.681

1.450

0.969

0.680

1.383

0.864

0.461

1.620

NO2

10 ppb

2.865

0.829

9.902

1.912

0.677

5.398

2.271

0.626

8.242

Ozone

10 ppb

1.359

0.641

2.879

2.314*

1.163

4.606

3.977*

1.277

12.383

Atmospheric pressure

1 hPa

0.978

0.921

1.038

1.012

0.956

1.071

1.017

0.942

1.098

Temperature

1 °C

0.886

0.775

1.013

0.928

0.786

1.096

1.013

0.808

1.270

Relative humidity

10 %

0.902

0.508

1.601

1.252

0.787

1.992

1.054

0.460

2.411

Wind speed

1 m/s

1.017

0.610

1.695

0.931

0.577

1.502

0.805

0.357

1.812

Daylight

1 h

0.893

0.790

1.010

1.036

0.929

1.156

0.914

0.761

1.097

  1. Associations are shown as the OR and 95 % CI per unit increment of each index
  2. NO 2 nitrogen dioxide, PM particulate matter
  3. * p < 0.05