Responsiveness of the PROMIS and FAAM Instruments in Foot and Ankle Orthopedic Population

Background: Investigating the responsiveness of an instrument is important in order to provide meaningful interpretation of clinical outcomes. This study examined the responsiveness of the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF), the PROMIS Pain Interference (PI), and the Foot and Ankle Ability Measure (FAAM) Sports subscale in an orthopedic sample with foot and ankle ailments. Methods: Patients presenting to an orthopedic foot and ankle clinic during the years 2014-2017 responded to the PROMIS and FAAM instruments prior to their clinical appointments. The responsiveness of the PROMIS PF v1.2, PROMIS PI v1.1, and FAAM Sports were assessed using paired samples t test, effect size (ES), and standardized response mean (SRM) at 4 different follow-up points. A total of 785 patients with an average age of 52 years (SD = 17) were included. Results: The PROMIS PF had ESs of 0.95 to 1.22 across the 4 time points (3, >3, 6, and <6 months) and SRMs of 1.04 to 1.43. The PROMIS PI had ESs of 1.04 to 1.63 and SRMs of 1.17 to 1.23. For the FAAM Sports, the ESs were 1.25 to 1.31 and SRMs were 1.07 to 1.20. The ability to detect changes via paired samples t test provided mixed results. But in general, the patients with improvement had statistically significant improved scores, and the worsening patients had statistically significant worse scores. Conclusion: The PROMIS PF, PROMIS PI, and FAAM Sports were sensitive and responsive to changes in patient-reported health.