Characteristics of patients with idiopathic inflammatory myopathies (IIMs) and individuals without IIM*
| Patients with IIM (n=1620) | Individuals without IIM (n=7797) | |
| Women, n (%) | 951 (59) | 4639 (60) |
| Birth year, median (Q1–Q3) | 1949 (1941–1964) | 1949 (1941–1964) |
| Living in Southern Sweden, n (%) | 1342 (83) | 6455 (83) |
| Age at inclusion, median (Q1–Q3) | 57 (44–66) | 57 (44–65) |
| IIM subtypes, n (%) | ||
| Juvenile IIM† | 128 (8) | – |
| Dermatomyositis‡ | 501 (31) | – |
| Other IIM§ | 991 (61) | – |
*Q1: the first quartile; Q3: the third quartile.
†Age at diagnosis ≤18 years of age.
‡With diagnostic code M33.1 and age at diagnosis >18 years of age.
§With diagnostic code M33.2, M33.9 or G72.4 and age at diagnosis >18 years of age.