Factors associated with moderate-to-severe exacerbations during the 12-month follow-up period (three-category multilevel model)
| Moderate-to-severe exacerbations during 12-month follow-up | ||||||
|---|---|---|---|---|---|---|
| ≥2 vs none | 1 vs none | ≥2 vs 1 | ||||
| Factor | OR | 95% CI | OR | 95% CI | OR | 95% CI |
| COPD exacerbations, 12 months prior to observation period start | ||||||
| No moderate event | Reference | |||||
| 1 moderate episode | 3.31 | 3.12 to 3.51 | 1.89 | 1.79 to 1.99 | 1.76 | 1.65 to 1.87 |
| ≥2 moderate episodes | 13.64 | 12.67 to 14.68 | 3.11 | 2.88 to 3.37 | 4.41 | 4.11 to 4.74 |
| No hospitalised episode | Reference | |||||
| ≥1 hospitalised episode | 2.13 | 1.95 to 2.31 | 1.49 | 1.38 to 1.61 | 1.44 | 1.32 to 1.57 |
| Airflow limitation level nearest to observation period start | ||||||
| Mild (FEV1 ≥80% predicted) | Reference | |||||
| Moderate (≥50% FEV1 <80% predicted) | 1.23 | 1.13 to 1.33 | 1.19 | 1.12 to 1.27 | 1.04 | 0.95 to 1.14 |
| Severe (≥30% FEV1 <50% predicted) | 1.81 | 1.66 to 1.98 | 1.36 | 1.27 to 1.47 | 1.37 | 1.24 to 1.50 |
| Very severe (FEV1 >30% predicted) | 2.37 | 2.08 to 2.70 | 1.59 | 1.41 to 1.79 | 1.56 | 1.37 to 1.78 |
| MRC dyspnoea scale nearest to observation period start | ||||||
| 1 | Reference | |||||
| 2 | 1.39 | 1.28 to 1.51 | 1.16 | 1.09 to 1.23 | 1.16 | 1.06 to 1.27 |
| 3 | 1.86 | 1.70 to 2.03 | 1.41 | 1.31 to 1.51 | 1.32 | 1.20 to 1.44 |
| 4 | 2.74 | 2.49 to 3.03 | 1.55 | 1.43 to 1.69 | 1.74 | 1.57 to 1.93 |
| 5 | 3.02 | 2.58 to 3.55 | 1.62 | 1.39 to 1.88 | 1.84 | 1.57 to 2.16 |
| Comorbidities, history of medical diagnosis before observation period start (absence is referent category) | ||||||
| Heart failure | 1.2 | 1.08 to 1.32 | 1.1 | 1.00 to 1.20 | 1.11 | 1.00 to 1.23 |
| Myocardial infarction | 1.13 | 1.03 to 1.24 | 1.15 | 1.06 to 1.24 | 0.96 | 0.87 to 1.05 |
| Rheumatological disease | 1.12 | 1.01 to 1.24 | 1.1 | 1.01 to 1.21 | 1.04 | 0.94 to 1.16 |
| Renal disease | 0.9 | 0.84 to 0.97 | 0.96 | 0.91 to 1.02 | 0.93 | 0.86 to 1.00 |
| Anxiety | 1.16 | 1.08 to 1.25 | 1.14 | 1.08 to 1.22 | 1.02 | 0.95 to 1.09 |
| Depression | 1.25 | 1.16 to 1.35 | 1.1 | 1.02 to 1.17 | 1.12 | 1.04 to 1.21 |
| Asthma | 1.51 | 1.43 to 1.60 | 1.24 | 1.19 to 1.30 | 1.23 | 1.16 to 1.30 |
| Cancer | 1.28 | 1.19 to 1.38 | 1.1 | 1.03 to 1.17 | 1.14 | 1.05 to 1.23 |
| Number of contacts with GP, 12 months prior to observation period start | ||||||
| Low: 0–5 | Reference | |||||
| Medium: 6–9 | 1.02 | 0.95 to 1.10 | 1.07 | 1.00 to 1.13 | 0.99 | 0.91 to 1.07 |
| High: ≥10 | 1.24 | 1.16 to 1.32 | 1.18 | 1.12 to 1.24 | 1.08 | 1.01 to 1.16 |
| Sex | ||||||
| Female | 1.19 | 1.13 to 1.26 | 1.12 | 1.07 to 1.17 | 1.07 | 1.01 to 1.14 |
Models further adjusted for age, smoking and BMI.
BMI, body mass index; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 s; GP, general practitioner; MRC, Medical Research Council.