Table 1.
Baseline characteristics of the dermatomyositis and non-inflammatory myositis patient cohorts before and after propensity matching
| Before propensity matching | After propensity matching | |||||
|---|---|---|---|---|---|---|
| Characteristic name | Vaccinated DM (N = 6104) | Vaccinated non-DM (N = 1,022,471) | Standard mean difference | Vaccinated DM (N = 6103) | Vaccinated non-DM (N = 6103) | Standard mean difference |
| BMI, kg/m2 | 30.33 ± 7.54 | 28.88 ± 6.69 | 0.20 | 30.33 ± 7.54 | 30.94 ± 7.47 | 0.08 |
| Age, years | 62.31 ± 13.49 | 54.36 ± 18.61 | 0.49 | 62.3 ± 13.49 | 62.3 ± 13.49 | 0.06 |
| Female | 4880 (79.95%) | 574,288 (56.17%) | 0.53 | 4879 (79.94%) | 4846 (79.40%) | 0.01 |
| White | 4273 (70.00%) | 669,741 (65.50%) | 0.10 | 4272 (70.00%) | 4335 (71.03%) | 0.02 |
| Black or African American | 1287 (21.09%) | 146,387 (14.32%) | 0.18 | 1287 (21.09%) | 1280 (20.97%) | 0.03 |
| Neoplasms | 4608 (75.49%) | 196,699 (19.24%) | 1.36 | 4607 (75.49%) | 4635 (75.95%) | 0.01 |
| Essential (primary) hypertension | 4482 (73.43%) | 253,824 (24.83%) | 1.11 | 4481 (73.42%) | 4537 (74.34%) | 0.02 |
| Chronic lower respiratory diseases | 3233 (52.97%) | 100,743 (9.85%) | 1.05 | 3232 (52.96%) | 3252 (53.29%) | 0.01 |
| Diabetes mellitus | 2184 (35.78%) | 102,052 (9.98%) | 0.65 | 2183 (35.77%) | 2202 (36.08%) | 0.01 |
| Ischemic heart diseases | 1912 (31.32%) | 76,153 (7.45%) | 0.63 | 1911 (31.31%) | 1931 (31.64%) | 0.01 |
| Nicotine dependence | 1374 (22.51%) | 44,831 (4.39%) | 0.55 | 1373 (22.50%) | 1330 (21.79%) | 0.02 |
| Chronic kidney disease | 1243 (20.36%) | 44,633 (4.37%) | 0.50 | 1242 (20.35%) | 1158 (18.97%) | 0.04 |
| Heart failure | 982 (16.09%) | 32,594 (3.19%) | 0.45 | 981 (16.07%) | 965 (15.81%) | 0.01 |
| Alcohol dependence | 264 (4.33%) | 8255 (0.81%) | 0.22 | 263 (4.31%) | 198 (3.24%) | 0.06 |
DM dermatomyositis, BMI body mass index
The assessed baseline characteristics among dermatomyositis patients and controls are described. Each cohort underwent 1:1 propensity score matching analysis to balance each cohort by demographics (age, sex, and race) and comorbidities (diabetes mellitus, essential hypertension, chronic lower respiratory disease, chronic kidney disease, nicotine dependence, alcohol dependence, heart failure, ischemic heart disease, body mass index, and neoplasms)