Table 1. Baseline demographic status and comorbidity compared between the non-PM/DM and PM/DM cohorts.
| Variable | Non-PM/DM cohort (N=13,740) (%) | PM/DM cohort (N=1,374) (%) | P value |
|---|---|---|---|
| Age, years (SD)* | 49.6 (14.4) | 49.6 (14.4) | 0.8823 |
| Sex | >0.99 | ||
| Female | 9,460 (68.9) | 946 (68.9) | |
| Male | 4,280 (31.1) | 428 (31.1) | |
| CCI score | <0.001 | ||
| 0 | 12,163 (88.5) | 649 (47.2) | |
| 1 | 808 (5.9) | 470 (34.2) | |
| 2 | 486 (3.5) | 162 (11.8) | |
| 3 or more | 283 (2.1) | 93 (6.8) | |
| Comorbidity | |||
| Asthma | 838 (6.1) | 165 (12.0) | <0.0001 |
| Hypertension | 3,602 (26.2) | 386 (28.1) | 0.1321 |
| Diabetes | 1,315 (9.6) | 145 (10.6) | 0.2398 |
| COPD | 1,067 (7.8) | 207 (15.1) | <0.0001 |
| Pneumonia | 1,926 (14) | 379 (27.6) | <0.0001 |
| Cancer | 338 (2.5) | 67 (4.9) | <0.0001 |
| CAD | 1,708 (12.4) | 220 (16.0) | 0.0001 |
| Heart failure | 268 (2.0) | 66 (4.8) | <0.0001 |
| PVD | 41 (0.3) | 23 (1.7) | <0.0001 |
| Medicine | |||
| Oral steroid | 9,544 (69.5) | 1,357 (98.8) | <0.001 |
| Methotrexate | – | 897 (65.3) | – |
*, t-test. PM/DM, polymyositis/dermatomyositis; SD, standard deviation; CCI score, Charlson comorbidity index score; COPD, chronic obstructive pulmonary disease; CAD, coronary artery disease; PVD, pulmonary vascular disease.