Table I.
Patient demographics and disease characteristics by race.
| n | All (n = 438) |
White (n = 347) |
Black (n = 57) |
Minority, non-Black (n = 34) |
p-value | |
|---|---|---|---|---|---|---|
|
| ||||||
| Demographics | ||||||
|
| ||||||
| Age at onset, years | 427 | 5.6 (3.7, 9.5) | 5.6 (3.6, 9.4) N=337 |
6.4 (4.8, 10.4) N = 56 |
5.0 (3.0, 10.7) N = 34 |
0.36 |
|
| ||||||
| Sex(female) | 438 | 309 (70.6) | 245 (70.6%) | 41 (71.9%) | 23 (67.7%) | 0.91 |
|
| ||||||
| Time to diagnosis, months | 423 | 4.0 (1.9, 10.7) | 4.3 (2.0, 10.7) N = 335 |
3.1 (1.9, 11.9) N = 55 |
3.1 (1.0, 7.8) N = 33 |
0.25 |
|
| ||||||
| Duration of disease, years | 427 | 3.1 (1.2, 6.2) | 3.3 (1.2, 6.3) N = 337 |
2.8 (1.2, 4.5) N = 56 |
3.6 (1.2, 6.8) N = 34 |
0.75 |
|
| ||||||
| Socioeconomic status | ||||||
|
| ||||||
| Insurance (yes) | 433 | 422 (97.5%) | 336 (98.3%) | 54 (94.7%) | 32 (94.1%) | 0.13 |
|
| ||||||
| Income | ||||||
| <$25,000/yr | 438 | 60 (13.7%) | 38 (11.0%) | 16 (28.1%) | 6 (17.7%) | <0.01 |
| $25–49,999/yr | 68 (15.5%) | 46 (13.3%) | 16 (28.1%) | 6 (17.7%) | ||
| $50–74,999/yr | 66 (15.1%) | 59 (17.0%) | 5 (8.8%) | 2 (5.9%) | ||
| $75–99,999/yr | 48 (11.0%) | 42 (12.1%) | 1 (1.8%) | 5 (14.7%) | ||
| $100–150,000/yr | 63 (14.4%) | 61 (17.6%) | 0 (0.0%) | 2 (5.9%) | ||
| >$150,000/yr | 41 (9.4%) | 31 (8.9%) | 5 (8.8%) | 5 (14.7%) | ||
| Unknown | 92 (21.0%) | 70 (20.2%) | 14 (24.6%) | 8 (23.5%) | ||
|
| ||||||
| Patient characteristics | ||||||
|
| ||||||
| Lipodystrophy | 434 | 20 (4.6%) | 14 (4.1%) | 3 (5.4%) | 3 (8.8%) | 0.43 |
|
| ||||||
| Calcinosis | 427 | 63 (14.8%) | 47 (13.8%) | 13 (24.1%) | 3 (9.1%) | 0.09 |
|
| ||||||
| ANA positive | 349 | 221 (63.3%) | 192 (68.1%) | 18 (41.9%) | 11 (45.8%) | <0.01 |
|
| ||||||
| Treatments | ||||||
|
| ||||||
| IV/Pulse corticosteroids | 406 | 248 (61.1%) | 195 (60.0%) | 33 (61.1%) | 20 (74.1%) | 0.69 |
|
| ||||||
| Oral corticosteroids | 410 | 398 (97.1%) | 319 (97.3%) | 53 (98.2%) | 26 (92.9%) | 0.20 |
|
| ||||||
| DMARDS/non-biologic DMARDS | 438 | 401 (91.6%) | 319 (91.9%) | 51 (89.5%) | 31 (91.2%) | 0.82 |
|
| ||||||
| Cytotoxic therapy1 | 398 | 6 (1.5%) | 4 (1.3%) | 2 (3.9%) | 0 (0.0%) | 0.27 |
|
| ||||||
| Biologics | 438 | 182 (41.6%) | 141 (40.6%) | 22 (38.6%) | 19 (55.9%) | 0.20 |
|
| ||||||
| IVIG | 437 | 172 (39.4%) | 134 (38.7%) | 20 (35.1%) | 18 (52.9%) | 0.47 |
|
| ||||||
| Disease activity | ||||||
|
| ||||||
| CHAQ2 | 427 | 0.12 (0, 0.63) | 0 (0, 0.6) N = 336 |
0.25 (0, 1) N = 57 |
0.25 (0, 1) N = 34 |
<0.01 |
|
| ||||||
| Patient global | 428 | 1 (0, 4) | 1 (0, 3) N = 337 |
3 (1, 4) N = 57 |
3 (0, 5) N = 34 |
0.02 |
|
| ||||||
| Physician global | 415 | 1 (0, 3) | 1 (0, 2) N = 327 |
1 (0, 3) N = 54 |
1.5 (0, 3) N = 34 |
0.25 |
|
| ||||||
| Weakness3 | 434 | 45 (10.4%) | 30 (8.8%) | 9 (15.8%) | 6 (17.6%) | 0.10 |
|
| ||||||
| Rash (facial erythema) | 433 | 137 (31.6%) | 114 (33.2%) | 14 (25%) | 9 (26.5%) | 0.37 |
|
| ||||||
| Gottron | 434 | 196 (45.2%) | 154 (44.8%) | 27 (48.2%) | 15 (44.1%) | 0.88 |
|
| ||||||
| CMAS4 | 271 | 50 (45, 52) | 50 (45, 52) N = 215 |
49 (43, 52) N = 33 |
48 (43, 52) N = 23 |
0.49 |
|
| ||||||
| HRQOL5 | 424 | 2 (2, 3) | 2 (2, 3) N = 333 |
3 (2, 3) N = 57 |
3 (2, 3) N = 34 |
0.02 |
|
| ||||||
| ACR6 class (worst) | ||||||
| I | 384 | 80 (20.8%) | 65 (21.5%) | 9 (18.4%) | 6 (18.8%) | 0.90 |
| II | 99 (25.8%) | 81 (26.7%) | 12 (24.5%) | 6 (18.8%) | ||
| III | 90 (23.4%) | 68 (22.4%) | 12 (24.5%) | 10 (31.3%) | ||
| IV | 115 (30.0%) | 89 (29.4%) | 16 (32.7%) | 10 (31.3%) | ||
Parenthesis indicates percentage or median interquartile 25–75% range (IQR). Chi square testing was used for comparison of counts; Kruskal-Wallis nonparametric testing was used for comparison of ordinal results. The p-values are for the comparisons between the White group and the other two groups.
1
Cytotoxic therapy=cyclophosphamide (pulse or oral)
2
CHAQ= Childhood Health Assessment Questionnaire, visit (higher is worse
3
Weakness = moderate or severe proximal weakness by evaluating physician, visit
4
CMAS= Childhood Myositis Assessment Scale, visit (higher is better)
5
HRQOL= Health Related Quality of Life, visit
6
ACR= American College of Rheumatology