Baseline characteristics of the study population
| Population characteristics | Total population at baseline, n=79 604 |
| Age (years), mean (SD) | 44 (13) |
| Female sex, % | 60.2 |
| Follow-up duration (years), mean (SD) | 4 (1) |
| Body mass index (kg/m2), mean (SD) | 26 (4) |
| Smoking never smokers, N(%) | 35 218 (47.3) |
| Ex-smokers, N(%) | 24 429 (32.8) |
| Current smokers, N(%) | 14 783 (19.5) |
| Education low, N(%) | 11 955 (15.8) |
| Medium, N(%) | 38 958 (51.5) |
| High, N(%) | 23 192 (30.7) |
| Unclassifiable, N(%) | 1380 (1.8) |
| Monthly income low, N(%) | 11 191 (15.2) |
| Medium, N(%) | 19 922 (27.0) |
| High, N(%) | 32 289 (43.8) |
| Unknown, N(%) | 10 376 (14.1) |
| Anti-inflammatory medication, % | 27.5 |
| Asthma, % | 8.2 |
| C reactive protein (mg/dL), median (IQR) | 1.20 (2.20) |
| Eosinophils (count ×106/L), median (IQR) | 150 (130) |
| Neutrophils (count ×106/L), median (IQR) | 3100 (1,390) |
| Δ eosinophil (count ×106/L), median (IQR) | 10 (80) |
| Δ neutrophil (count ×106/L), median (IQR) | 60 (1,010) |
| Allergens exposed, % | 31.5 |
| Reactive chemicals exposed, % | 32.1 |
| Pesticides exposed, % | 8.5 |
| Micro-organisms exposed, % | 6.8 |
Δ-Difference in numbers of eosinophil and neutrophil between baseline and follow-up.
Education: low education (No training, primary education, lower or pre-vocational education); medium education (General secondary education, secondary vocational or professional guiding, preuniversity education); high education (Higher professional or university degree); Unclassifiable (Subjects with other than above-mentioned education).
Monthly income: low income (monthly net income ≤ €1500); medium income (monthly net income between €1500 and €2500); high income (monthly net income ≥ €2500); unknown (I don’t know/ I don’t want to say).
Smoking: never smokers (Never smoked or smoked for < 1 year); ex-smokers (Smoked for ≥ 1 yearand stopped smoking for ≥ 1 month); current smokers (Current smoker or stopped smoking < 1 month)
Anti-inflammatory medication: prescribed use of steroids and/or non-steroidal anti-inflammatory drugs.
IQR, Interquartile range; SD, Standard deviation .