Adjusted yearly incidence rate ratio (IRR) with 95% confidence intervals calculated with negative binomial regression for experiencing moderate and/or severe chronic obstructive pulmonary disease (COPD) exacerbations during follow-up in the Bergen COPD Cohort Study

IRR (95% CI)p-value
Desaturation during 6MWT
 Yes1.6 (1.2–2.2)<0.01
 Male1.0 (0.7–1.4)0.97
Age per 10-year increase1.0 (0.8–1.2)0.85
Body composition
 Cachectic0.8 (0.5–1.1)0.18
 Obese1.7 (1.1–2.8)0.03
Smoking habits
 Daily smoker0.9 (0.7–1.2)0.60
FEV1 % pred per 10% reduction1.2 (1.1–1.3)<0.01
Exacerbations in 12 months before inclusion in study
 Yes2.2 (1.6–3.0)<0.001
PaO2 at baseline per kPa increase1.0 (0.9–1.1)0.79
Charlson comorbidity score
 21.0 (0.7–1.3)0.94
 30.9 (0.6–1.3)0.46
 ≥41.2 (0.7–2.1)0.54
6MWD per 10-m increase0.9 (0.7–0.99)0.03
Height per cm increase1.0 (0.9–1.0)0.72
Weight per kg increase0.98 (0.97–0.99)<0.01
  • 6MWT: 6-min walk test; FEV1: forced expiratory volume in 1 s; PaO2: arterial oxygen tension; 6MWD: 6-min walking distance.