What is the minimal clinically important differences of patient-reported outcomes measurement information system in patients with distal femur fractures?

INTRODUCTION

Determining the minimal clinically important difference (MCID) in patient-reported outcome measures is critical to improve patient care. This study sought to establish the MCID of the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Short Form 10a (PF-SF10a) and PROMIS Global-Physical (G-P) in patients with operatively treated distal femur fractures.

METHODS

Patients with AO/OTA type 33A or 33C distal femur fractures who underwent operative treatment with lateral plate fixation at two Level 1 Trauma Centers were retrospectively identified. The following MCIDs for PROMIS PF-SF10a and PROMIS G-P were established: overall, 9-12 weeks, 3-6 months, and 6-24 months after surgery.

RESULTS

Ninety-one patients with 253 PROMIS PF-SF10a and 174 PROMIS G-P scores were included. The MCID thresholds for PROMIS PF-SF10a and PROMIS G-P were: 3.53 and 3.23 overall; 2.21 at 9-12 weeks (only PROMIS PF-SF10a); 3.04 and 2.71 at 3-6 months; and 3.83 and 3.34 at 6-24 months. Overall, 70.4% of patients achieved MCID for PROMIS PF-SF10a and 55.1% for PROMIS G-P. The overall MCID thresholds and achievement rates for PROMIS PF-SF10a in patients with and without reoperations were 4.66 and 56.3%, and 3.35 and 71.8%, respectively. Female patients (OR = 2.01, p = 0.046) and non-ambulatory patients pre-injury (OR = 7.30, p = 0.002) were independent risk factors for failure to achieve MCID for PROMIS PF-SF10a.

CONCLUSIONS

This study established an MCID threshold of 3.53 for PROMIS PF-SF10a and 3.23 for PROMIS G-P in patients with operatively treated distal femur fractures. Female and non-ambulatory patients have higher odds of not achieving MCID.

LEVEL OF EVIDENCE: III.