Validation of two simple patient-centered outcome measures for virtual monitoring of patients with idiopathic inflammatory myositis.

BACKGROUND Telemedicine has changed the landscape of patient care with wider use of patient-centered outcome measures (PCOMs). We evaluated two novel task-based PCOMs namely ten times arm lift (AL) test and two-minute walk distance (2MWD) in idiopathic myositis (IIM). METHODS This was a cross-sectional observational study with the enrolment of adult IIM (ACR/EULAR criteria) patients with active/inactive disease. Active disease was defined as any two of increase in immunosuppression within 3 months, elevated muscle enzymes, physician VAS ≥ 2, worsened cutaneous disease, or fall in MMT8   12.8 s had 94% negative predictive value (NPV) for active muscle disease. In the validation cohort (47 patient visits among 26 patients), AL significantly differentiated between active vs. inactive disease with an NPV of 95%. CONCLUSIONS AL test exhibits pilot evidence of construct and discriminant validity in patients with IIM requiring further evaluation. 2MWD was not a good test for outcome evaluation of IIM patients. Key Points • Novel task-based patient-centered outcome measures were evaluated for remote monitoring of muscle strength in IIM. • Ten times arm lift (AL) test showed strong test-retest reliability as well as provide pilot evidence of construct and discriminant validity in patients with IIM unlike 2-min walk distance. • This provides preliminary evidence to further evaluate the role of AL as patient-centered outcome measure in patients with IIM for virtual clinical trials.