Fitbit as an activity monitor in idiopathic inflammatory myopathy: results from a real-world cohort

Key Points

• To evaluate the use of Fitbit as an activity monitor in patients with idiopathic inflammatory myopathy (IIM).
• Assessed compliance with Fitbit PAM variables in a large cohort of IIM patients.
• Evaluated psychometric properties including test-retest reliability and validity of the Fitbit measurements.
• Compared Fitbit data with traditional measures of patient performance and disease activity.
• Fitbit PAM variables showed strong test-retest reliability with high validity.
• Patients demonstrated favorable compliance with the use of Fitbit for self-monitoring.
• Fitbit metrics can effectively track aspects of quality of life and disease activity.