Table 2.
Baseline demographic characteristics and COPD severity of study cohorts
| Patient characteristics | Similar-devices cohort (n=8,225) | Mixed-devices cohort (n=8,225) |
|---|---|---|
| Demographic characteristics | ||
| Age (years) | ||
| 40–60, n (%) | 1,856 (22.6) | 1,856 (22.6) |
| 61–80, n (%) | 5,863 (71.3) | 5,863 (71.3) |
| >80, n (%) | 506 (6.2) | 506 (6.2) |
| Mean (SD) | 67.3 (9.9) | 67.2 (9.7) |
| Male, n (%) | 4,645 (56.5) | 4,645 (56.5) |
| Body mass index (kg/m2) | ||
| <18.5, n (%) | 151 (1.8) | 151 (1.8) |
| 18.5–24.9, n (%) | 2,892 (35.2) | 2,892 (35.2) |
| 25–29.9, n (%) | 2,981 (36.2) | 2,981 (36.2) |
| ≥30, n (%) | 2,201 (26.8) | 2,201 (26.8) |
| Mean (SD) | 27.4 (6.1) | 27.4 (5.7) |
| Smoking status (closest to index date) | ||
| Nonsmoker, n (%) | 584 (7.1) | 584 (7.1) |
| Current smoker, n (%) | 3,029 (36.8) | 3,029 (36.8) |
| Ex-smoker, n (%) | 4,612 (56.1) | 4,612 (56.1) |
| COPD severity | ||
| FEV1% predicteda | ||
| GOLD 1: FEV1 ≥80 (mild), n (%) | 717 (8.7) | 717 (8.7) |
| GOLD 2: 50≤ FEV1 <80 (moderate), n (%) | 4,659 (56.6) | 4,659 (56.6) |
| GOLD 3: 30≤ FEV1 <50 (severe), n (%) | 2,003 (24.4) | 2,003 (24.4) |
| GOLD 4: FEV1 <30 (very severe), n (%) | 846 (10.3) | 846 (10.3) |
| Mean (SD) | 55.9 (22.6) | 55.7 (22.5) |
| COPD exacerbationsb | ||
| 0, n (%) | 4,226 (51.4) | 4,226 (51.4) |
| 1, n (%) | 2,394 (29.1) | 2,394 (29.1) |
| 2, n (%) | 972 (11.8) | 972 (11.8) |
| ≥3, n (%) | 633 (7.7) | 633 (7.7) |
Notes: Variables were not compared statistically as all were used in matching process.
a
FEV1 % predicted grouped by GOLD classifications;
b
moderate/severe exacerbations were identified by acute course of oral corticosteroids (OCS) unlikely to be maintenance therapy, antibiotics prescribed within a lower respiratory consultation or admission to hospital/emergency department for COPD or following lower respiratory consultation. Further details of prescriptions of OCS and antibiotics are found in Table 3.
Abbreviations: SD, standard deviation; FEV1, forced expiratory volume in 1 second; GOLD, Global initiative for chronic Obstructive Lung Disease.