Comparison of physician-diagnosed IIM subgroups with IIM subgroups defined according to the classification tree among patients meeting the EULAR/ACR classification criteria for IIM
| Physician-diagnosed subgroups | Classification tree subgroups* | Total | ||||
| JDM | DM | ADM | IBM | PM | ||
| JDM | 235 | 0 | 0 | 0 | 0 | 235 |
| DM | 0 | 191 | 6 | 2 | 15 | 214 |
| ADM | 1 | 1 | 30 | 0 | 0 | 32 |
| IBM | 0 | 0 | 0 | 66 | 5 | 71 |
| PM | 0 | 7 | 0 | 3 | 131 | 141 |
| IMNM | 0 | 0 | 0 | 0 | 10 | 10 |
| Total | 236 | 199 | 36 | 71 | 161 | 703 |
| % of all IIM | 33.6 | 28.3 | 5.1 | 10.1 | 22.9 | |
| % of adult IIM | – | 42.6 | 7.7 | 15.2 | 34.5 | |
*Classification of IIM by the EULAR/ACR classification criteria for IIM, using a 55% probability cut-off for classification, followed by the classification tree for subclassification.
ACR, American College of Rheumatology; ADM, amyopathic dermatomyositis; DM, dermatomyositis; EULAR, European League Against Rheumatism; IBM, inclusion body myositis; IIM, idiopathic inflammatory myopathies; IMNM, immune-mediated necrotising myopathy; JDM, juvenile dermatomyositis; PM, polymyositis.