How Should We Define Clinically Significant Improvement on Patient-Reported Outcomes Measurement Information System Test for Patients Undergoing Knee Meniscal Surgery?

Purpose: The purpose of the study was to define the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) thresholds for the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) computerized adaptive test (CAT) instrument in patients undergoing arthroscopic meniscal surgery. Methods: The PROMIS PF CAT was administered preoperatively and postoperatively to patients undergoing arthroscopic meniscal surgery. At 6 months postoperatively, patients graded their knee function based on a domain-specific anchor question. A satisfaction anchor question was used to indicate achievement of the PASS. Receiver operating characteristic analysis determined the relevant psychometric values. Cutoff analysis was performed to find preoperative patient-reported outcome scores predicting achievement of clinically significant outcomes (CSOs). Results: A total of 73 patients (41.1% female patients) were included, with a mean age of 44.9 +/- 12.8.0 years and average follow-up period of 24.0 +/- 1.2 weeks. The MCID on the PROMIS PF CAT was calculated to be 2.09 (area under the curve [AUG], 0.75; 95% CI, 0.57-0.94). Net score improvement equivalent to achievement of SCB was found to be 6.50 (AUC, 0.77; 95% CL 0.55-0.99). The PASS was found to be 46.1 (AUC, 0.86; 95% CL 0.76-0.96). A preoperative score below 37.6 on the PROMIS PF CAT predicted achievement of the MCID (AUC, 0.76; 95% CI, 0.62-0.87), whereas scores above 41.9 predicted achievement of the PASS (AUC, 0.77; 95% CL 0.65-0.90). Higher baseline functional status and the absence of pre-existing arthritis were also found to be statistically significant predictors of achieving C SOs. Conclusions: Our study defined the MCID, SCB, and PASS for the PROMIS PF CAT. We found that a preoperative score below 37.6 was predictive of achieving a meaningful clinical change with surgery whereas a preoperative score above 41.9 was predictive of patients who would attain an acceptable postoperative health state. In addition, exercising more days per week and the absence of arthritis increased the likelihood of achieving postoperative CSOs.