Frequency of patients who fit the criteria for inactive disease in the reference sample (off therapy at 24 months) versus the comparison sample (baseline data of a random sample of patients selected from all patients on therapy at 24 months)
| Inactive disease criteria | Reference sample, patients off therapy (N=38) | Comparison sample, active patients (N=76) | Sensitivity | Specificity | Cohen's κ |
|---|---|---|---|---|---|
| Top criteria derived by the Study Steering Committee | |||||
| C1: 3 of 4 (CPK ≤150, CMAS ≥48, MMT ≥78, MD-GLOVAS ≤0.2) | 30/31 | 0/76 | 0.97 | 1.0 | 0.98 |
| C2: 3 of 4 (aldolase ≤6, CMAS ≥48, MMT ≥78, MD-GLOVAS ≤0.2) | 29/30 | 0/75 | 0.97 | 1.0 | 0.98 |
| C3: 3 of 4 (CPK ≤150, CMAS ≥48, MMT ≥78, MYOACT ≤0.2) | 31/33 | 0/76 | 0.94 | 1.0 | 0.96 |
| C4: 3 of 4 (LDH ≤150, CMAS ≥48, MMT ≥78, MD-GLOVAS ≤0.2) | 31/33 | 0/76 | 0.94 | 1.0 | 0.96 |
| C5: 3 of 4 (CPK ≤150, CMAS ≥48, MMT=80, MD-GLOVAS ≤0.2) | 30/32 | 0/76 | 0.94 | 1.0 | 0.95 |
| C6: 3 of 4 (LDH ≤150 and ALT ≤35, CMAS ≥48, MMT ≥78, MD- GLOVAS ≤0.2) | 30/32 | 0/75 | 0.94 | 1.0 | 0.95 |
| Top criteria derived from literature | |||||
| C7: MMT=80 and (CPK, LDH, AST, ALT)=normal and MITAX=03 | 18/31 | 0/76 | 0.58 | 1.0 | 0.66 |
| C8: MMT=80 and CPK=normal and MITAX=038 | 14/29 | 0/76 | 0.48 | 1.0 | 0.57 |
| C9: MD-GLOVAS=0 and MMT=80 and (CPK, LDH, AST, ALT)=normal and MITAX=042 | 11/30 | 0/76 | 0.37 | 1.0 | 0.45 |
| C10: MMT=80 and enzymes normal and MITAX=043 | 11/31 | 0/76 | 0.35 | 1.0 | 0.44 |
| C11: MITAX=0 and MMT=80 and CMAS=52 and enzymes=normal9 | 9/32 | 0/76 | 0.28 | 1.0 | 0.36 |
| C12: MMT=80 and (CPH or LDH normal) and skin DAS=041 | 9/34 | 0/76 | 0.26 | 1.0 | 0.33 |
| C13: Skin DAS=0 and MMT=80 and enzymes=normal44 | 9/34 | 0/76 | 0.26 | 1.0 | 0.33 |
| C14: Skin DAS=0 and MMT=80 and enzymes normal and MITAX=039 40 | 7/34 | 0/76 | 0.21 | 1.0 | 0.26 |
Criteria were formulated from Step 2 (tables 1 and 2) or derived from the literature.3 ,9 ,38,–,44 The last three columns report accuracy measures (sensitivity, specificity and Cohen's κ). Definitions are sorted by decreasing values of Cohen's κ and numbered as criteria 1 (C1), C2, etc.
ALT, alanine aminotransferase; AST, aspartate aminotransferase; C, criteria; CPK, creatine kinase; CMAS, Childhood Myositis Assessment Scale; LDH, lactate dehydrogenase; MMT, manual muscle testing; MD-GLOVAS, Physician's global assessment of patient's overall disease activity; MYOACT, Myositis Disease Activity Assessment; MITAX, Myositis Intent-to-Treat Activity Index A–E version.