Characteristics of study population in the index year
| Characteristic | Patients with severe asthma (N=13 467) |
|---|---|
| Age, median (IQR) | 36.8 (26.6, 43.8) |
| Sex, N (%) | |
| Men | 6094 (45) |
| Women | 7373 (55) |
| Socioeconomic status, N (%) | |
| Low | 6326 (47) |
| Middle | 2649 (20) |
| High | 4492 (33) |
| Comorbidity, N (%) | |
| CCI=0 | 1969 (15) |
| CCI=1 | 10 345 (77) |
| CCI=2 | 657 (5) |
| CCI≥3 | 496 (4) |
| Moderate to severe exacerbation, N (%) | |
| None | 3262 (24) |
| ≥1 exacerbation | 10 205 (76) |
| PDC by asthma controller medications | |
| PDC <50% | 8297 (62) |
| PDC ≥50%–80% | 3777 (28) |
| PDC ≥80% | 1393 (10) |
| Severity in the past year, N (%) | |
| No asthma* | 1785 (13) |
| Mild | 3674 (27) |
| Moderate | 8008 (59) |
| Severity in the year before last year, N (%) | |
| No asthma* | 3262 (24) |
| Mild | 4192 (31) |
| Moderate | 6013 (45) |
*Refers to a patient-year in which the intensity of asthma-related resource utilisation did not satisfy the case definition of asthma. In the analysis, patients with no asthma prior to the index year were assumed to be associated with mild asthma.
CCI, Charlson Comorbidity Index; PDC, proportion of days covered.