Table 1.
Demographic and pre-index clinical characteristics prior to matching
| Characteristic | RCI (N=132) | IVIg (N=1,150) | Rituximab (N=562) | IVIg+ rituximab (N=123) | RCI vs IVIg STDdiff | RCI vs rituximab STDdiff | RCI vs IVIg+ rituximab STDdiff |
|---|---|---|---|---|---|---|---|
| Age (at index date), mean (SD) | 52.6 (11.82) | 46.6 (18.43) | 51.7 (14.02) | 47.8 (15.10) | 38.8 | 6.9 | 35.7 |
| Female, n (%) | 88 (66.7) | 796 (69.2) | 391 (69.6) | 81 (65.9) | 5.5 | 6.2 | 1.7 |
| Indication of cancer, n (%) | 21 (15.9) | 256 (22.3) | 153 (27.2) | 34 (27.6) | 16.2 | 27.7 | 28.6 |
| Prior DM/PM treatment, n (%) | 121 (91.7) | 885 (77.0) | 516 (91.8) | 114 (92.7) | 41.2 | 0.5 | 3.8 |
| Prior corticosteroids (prednisone or methylprednisolone), n (%) | 110 (83.3) | 804 (69.9) | 502 (89.3) | 110 (89.4) | 32.1 | 17.5 | 17.8 |
| Prior azathioprine, n (%) | 38 (28.8) | 190 (16.5) | 102 (18.1) | 30 (24.4) | 29.6 | 25.2 | 9.9 |
| Prior methotrexate, n (%) | 53 (40.2) | 385 (33.5) | 211 (37.5) | 42 (34.1) | 13.8 | 5.3 | 12.4 |
| Prior MMF, n (%) | 29 (22.0) | 183 (15.9) | 99 (17.6) | 29 (23.6) | 15.5 | 10.9 | 3.8 |
| Deyo’s adapted CCI score, mean (SD) | 1.9 (1.58) | 1.8 (1.94) | 2.2 (2.07) | 2.3 (2.45) | 8.4 | 14.0 | 17.0 |
| Elixhauser Comorbidity Index score (≥2), n (%) | 86 (65.2) | 617 (53.7) | 335 (59.6) | 88 (71.5) | 23.5 | 11.4 | 13.7 |
| Chronic Disease Score, mean (SD) | 7.6 (3.78) | 5.8 (4.15) | 6.5 (4.30) | 6.3 (4.35) | 44.5 | 27.2 | 32.5 |
| Pre-index number of hospitalizations, mean (SD) | 2.4 (8.34) | 5.1 (13.54) | 4.8 (11.47) | 7.8 (17.24) | 23.7 | 23.9 | 39.5 |
| Pre-index total costs (excluding DM/PM medication costs), mean (SD) | 35,970 (46,591) | 55,195 (92,041) | $42,798 ($75,189) | $71,535 ($119,312) | 26.4 | 10.9 | 39.3 |
Abbreviations: CCI, Charlson Comorbidity Index; DM, dermatomyositis; IVIg, intravenous immunoglobulin; MMF, mycophenolate mofetil; PM, polymyositis; RCI, repository corticotropin injection; SD, standard deviation; STDiff, standard difference.