Table 5. Associations between spirometry-based COPD and potential risk factors and severity measures.
COPD is defined on pre-and post-measurements and on LLN-definition and GOLD-definition.
| Spirometry LLN | Spirometry GOLD | |||
|---|---|---|---|---|
| Pre-measurement | Post-measurement | Pre-measurement | Post-measurement | |
| N (%) | 163 (9.1%) | 105 (5.9%) | 294 (16.4%) | 196 (10.9%) |
| Age (per 10 years) | 0.91 (0.77–1.07) | 1.10 (0.87–1.39) | 1.41 (1.21–1.64) | 1.81 (1.47–2.22) |
| Female gender | 0.77 (0.55–1.08) | 0.74 (0.48–1.13) | 0.45 (0.35–0.60) | 0.49 (0.35–0.68) |
| Ever smoker | 2.75 (1.87–4.06) | 4.10 (2.35–7.17) | 2.40 (1.79–3.23) | 3.50 (2.35–5.22) |
| Pack years (per 10 years)* | 1.25 (1.14–1.37) | 1.31 (1.19–1.44) | 1.21 (1.12–1.32) | 1.23 (1.13–1.35) |
| Occupational exposure to vapors, gases, dust or fumes | 1.01 (0.69–1.47) | 1.05 (0.67–1.65) | 1.04 (0.77–1.40) | 1.17 (0.82–1.66) |
| BMI < 20 (ref = BMI 20–25) | 3.54 (1.48–8.46) | 6.44 (2.43–17.11) | 4.27 (1.79–10.18) | 2.91 (1.04–8.11) |
| BMI > 25 (ref = BMI 20–25) | 0.61 (0.43–0.88) | 0.57 (0.36–0.90) | 0.68 (0.50–0.92) | 0.57 (0.40–0.82) |
| High education level (ref = low/ medium) | 0.77 (0.52–1.14) | 0.47 (0.27–0.83) | 0.81 (0.59–1.11) | 0.63 (0.42–0.94) |
| Current asthma | 2.93 (1.62–5.29) | 2.48 (1.18–5.19) | 2.97 (1.72–5.12) | 2.52 (1.33–4.79) |
| Self-reported ever allergy | 1.15 (0.81–1.63) | 1.22 (0.79–1.88) | 1.07 (0.81–1.43) | 1.29 (0.91–1.81) |
| Atopy | 1.41 (0.98–2.01) | 1.30 (0.83–2.04) | 1.07 (0.79–1.45) | 1.04 (0.72–1.50) |
| > 1 positive for specific IgE | 1.36 (0.90–2.05) | 1.46 (0.88–2.44) | 1.15 (0.82–1.63) | 1.29 (0.85–1.96) |
| Total IgE > = 100 IU/ml | 1.95 (1.33–2.87) | 1.92 (1.20–3.08) | 1.53 (1.09–2.15) | 1.37 (0.91–2.06) |
| CCQ-score †, mean (SD) | 2.10 (1.65–2.68) | 2.97 (2.25–3.92) | 1.76 (1.42–2.19) | 2.15 (1.68–2.76) |
| Less than good self-reported health ‡ | 1.86 (1.29–2.68) | 2.29 (1.48–3.53) | 1.44 (1.06–1.97) | 1.55 (1.09–2.23) |
OR and 95% CI were adjusted for age, gender, ever smoking and pack years (number of pack years was mean-centered for ex- and current smokers). Bold type indicates statistical significance (p <0.05). Spirometry: pre and post-bronchodilator lung function measurement. Used definitions for COPD based on different databases are presented in Table 2.
*Mean packyears are calculated for ex-smokers and current smokers.
† Clinical COPD Questionnaire (CCQ)-score [23].
‡Less than good self-reported health: bad/moderate/reasonable, reference category: good/excellent self-reported health.