Minimal Clinically Important Differences of Patient-Reported Outcomes Measurement Information System Physical Function in Patients With Tibial Shaft Fracture.

Abstract

To calculate the minimal clinically important differences (MCIDs) of patient-reported outcomes measurement information system physical function (PROMIS PF) scores for patients with operatively treated tibial shaft fractures. Retrospective Cohort Study. A Level 1 trauma center. All operatively treated tibial shaft fractures identified by Current Procedural Terminology codes. Enrolled patients treated acutely with operative fixation of their tibia. MCIDs were calculated by distribution-based and anchor-based methods, calculated from PROMIS PF scores completed at least at two-time points postoperatively. MCIDs were calculated at different time points including overall, 7-12 weeks, 3-6 months, and 6-24 months. MCIDs were calculated for different subgroups including open fractures, closed fractures, any complications, and no complications. MCID for PROMIS PF scores was 5.7 in the distribution-based method and 7.84 (SD 18.65) in the anchor-based method. At 6-24 postoperatively, the months the distribution-based MCID was 5.95 from a postoperative baseline 27.83 (8.74) to 42.85 (9.61), P < 0.001. At 6-24 months, the anchor-based MCID was 10.62 with a score difference between the improvement group of 16.03 (10.73) and the no improvement group of 5.41 (15.75), P < 0.001. Patients with open fractures (distribution-based 6.22 and anchor-based 8.05) and any complications (distribution-based 5.71 and anchor-based 9.29) had similar or higher MCIDs depending on the methodology used than the overall cohort MCIDs. This study identified distribution-based MCID of 5.7 and anchor-based MCID of 7.84 calculated from PROMIS PF scores in operative tibial shaft fractures. Distribution-based methods yielded smaller MCIDs than anchor-based methods. These MCID scores provide a standard to compare clinical and investigational outcomes.