The Responsiveness of the Patient-Reported Outcomes Measurement Information System Upper Extremity and Physical Function in Patients With Cubital Tunnel Syndrome

Abstract

The Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity (UE) and PROMIS Physical Function (PF) are increasingly referenced patient-reported outcomes. To interpret treatment effects with these patient-reported outcomes, investigators must understand magnitudes of change that represent clinically relevant improvement. This study assessed the responsiveness of PROMIS UE and PF in patients with cubital tunnel syndrome. A retrospective analysis of PROMIS UE and PROMIS PF computer adaptive test scores was performed for patients treated nonoperatively for cubital tunnel syndrome over 3 years at a tertiary institution. The Patient-Reported Outcomes Measurement Information System UE and PROMIS PF outcome scores were collected at initial and return clinic visits. At follow-up appointments, patients completed clinical anchor questions evaluating their degree of interval clinical improvement. Anchor questions allowed categorization of patients into groups that had experienced "no change," "minimal change," and "much change." Minimal clinically important difference (MCID) values were calculated for the PROMIS assessments with anchor-based and distribution-based methods. A total of 304 patients with PROMIS PF scores and 111 with PROMIS UE scores were analyzed. The MCID for the PROMIS UE was 3.1 (95% confidence interval, 1.4-4.8) using the anchor-based method and 3.7 (95% confidence interval, 2.9-4.4) using the distribution-based method. These point estimates exceeded the minimal detectable change of 2.3. The MCID for the PROMIS PF was unable to be determined in this patient sample because patients reporting mild change did not have score changes exceeding measurement error. The PROMIS UE v2.0 computer adaptive test detected minimal change in patients managed nonoperatively for cubital tunnel syndrome with an estimated MCID range of 3.1-3.7. While PROMIS PF has demonstrated acceptable performance in patients with a variety of upper extremity conditions, for cubital tunnel syndrome, it was less able to detect subtle change. PROMIS UE appears more responsive to subtle changes in cubital tunnel syndrome symptoms. Patient-reported outcomes may have varied responsiveness depending on the condition studied.