Skip to main content

Table 4 OR of diary-reported symptoms and medication use associated with exposure to pollen at lag 0–2 and lag 0–6 and air pollution at lag 0–2 exposure to pollen and air pollutants in single-, pairwise-, and multi-exposure models with 95% confidence interval (pooled results). Significant results are indicated with bold font

From: Birch pollen, air pollution and their interactive effects on airway symptoms and peak expiratory flow in allergic asthma during pollen season – a panel study in Northern and Southern Sweden

Model adjustment

Pollen – Lag 0–2

Pollen – Lag 0–6

NOx – Lag 0–2

O3 – Lag 0–2

PM2.5 – Lag 0–2

 

OR (95% CI)

OR (95% CI)

OR (95% CI)

OR (95% CI)

OR (95% CI)

Rhinitis or eye irritation

  Adjusted for Pollen

1.44 (1.36; 1.52)

1.67 (1.57; 1.78)

   

  + NOx

1.17 (1.02; 1.35)

1.28 (1.08; 1.53)

1.06 (0.86; 1.29)

  

  + O3

1.14 (1.02; 1.26)

1.23 (1.12; 1.35)

 

0.81 (0.56; 1.17)

 

  + PM2.5

1.18 (1.01; 1.37)

1.35 (1.06; 1.72)

  

0.88 (0.78; 1.01)

  + NOx, O3, PM2.5

1.25 (1.16; 1.35)

1.39 (1.27; 1.51)

0.71 (0.42; 1.19)

1.02 (0.34; 3.04)

1.16 (1.02; 1.32)

Dyspnea

  Adjusted for Pollen

1.17 (1.10; 1.25)

1.23 (1.09; 1.37)

   

  + NOx

1.04 (0.96; 1.14)

1.12 (1.02; 1.23)

0.75 (0.54; 1.05)

  

  + O3

1.03 (0.95; 1.12)

1.09 (1.00; 1.20)

 

1.06 (0.69; 1.61)

 

  + PM2.5

1.01 (0.93; 1.10)

1.08 (0.98; 1.19)

  

0.91 (0.55; 1.50)

  + NOx, O3, PM2.5

1.03 (0.95; 1.13)

1.09 (0.99, 1.20)

0.79 (0.54; 1.15)

0.96 (0.66; 1.40)

1.03 (0.81; 1.33)

Dry cough

  Adjusted for Pollen

1.05 (0.90; 1.24)

1.08 (0.85; 1.35)

   

  + NOx

1.10 (1.02; 1.18)

1.14 (1.05; 1.24)

0.97 (0.72; 1.31)

  

  + O3

1.09 (1.01; 1.17)

1.14 (1.05; 1.24)

 

1.15 (1.00; 1.31)

 

  + PM2.5

1.07 (0.99; 1.16)

1.14 (1.05; 1.24)

  

1.18 (1.05; 1.33)

  + NOx, O3, PM2.5

1.09 (1.01; 1.17)

1.15 (1.05; 1.28)

0.99 (0.72; 1.35)

1.14 (1.09; 1.19)

1.01 (0.97; 1.06)

Allergy medication

  Adjusted for Pollen

1.58 (1.44; 1.74)

1.85 (1.60; 2.14)

   

  + NOx

1.23 (1.12 1.35)

1.16 (1.08; 1.24)

0.72 (0.52; 1.00)

  

  + O3

1.19 (1.08; 1.30)

1.15 (1.07; 1.23)

 

1.29 (1.02; 1.62)

 

  + PM2.5

1.15 (1.01; 1.26)

1.16 (1.07; 1.23)

  

1.15 (1.02; 1.31)

  + NOx, O3, PM2.5

1.17 (1.07; 1.29)

1.15 (1.06; 1.25)

0.74 (0.59; 0.92)

1.01 (0.78; 1.32)

1.25 (1.07; 1.46)

Bronchodilating medication

  Adjusted for Pollen

1.15 (1.08; 1.21)

1.23 (1.16; 1.32)

   

  + NOx

1.07 (0.87; 1.32)

1.10 (0.85; 1.42)

0.84 (0.81; 0.88)

  

  + O3

1.06 (0.87; 1.30)

1.09 (0.83; 1.43)

 

1.02 (0.77; 1.34)

 

  + PM2.5

1.07 (0.97; 1.30)

1.10 (0.82; 1.49)

  

0.97 (0.97; 0.99)

  + NOx, O3, PM2.5

1.07 (0.86; 1.33)

1.12 (0.84; 1.50)

0.81 (0.62; 1.07)

1.04 (0.72; 1.49)

1.09 (0.86; 1.37)

  1. For eye irritation/rhinitis, dyspnea, dry cough, allergy medication, “Yes” vs. “No”. For bronchodilating medication, reporting “more than yesterday” vs. “No”, “Less”, or “Same”
  2. Results from pooled with meta-analysis of mixed model results for pollen (single-exposure), pollen and pairwise combinations of pollen and either NOx, O3 and PM2.5, and multi-exposure models adjusted for pollen. All models were adjusted for relative humidity and temperature, with identification number as a random effect. Associations for are reported per 100 grains/m3 for pollen and per city-specific IQR for pollutants (Göteborg: NOx 20.0 µg/ m3, O3 22.9 µg/ m3, PM2.5 3.3 µg/ m3, Umeå: NOx 14.7 µg/m3, O3 24.1 µg/ m3, PM2.5 2.8 µg m3)