Threshold Values for Success After Hip Arthroscopy Using the Patient-Reported Outcomes Measurement Information System Assessment: Determining the Minimum Clinically Important Difference and Patient Acceptable Symptomatic State.

BACKGROUND

Threshold values for patient-reported outcome measures, such as the minimum clinically important difference (MCID) and patient acceptable symptomatic state (PASS), are important for relating postoperative outcomes to meaningful functional improvement.

PURPOSE

To determine the PASS and MCID after hip arthroscopy for femoroacetabular impingement using the Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaire.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

A consecutive series of patients undergoing primary hip arthroscopy for femoroacetabular impingement were administered preoperative and minimum 1-year postoperative PROMIS surveys focusing on physical function (PF) and pain interference (PI). External anchor questions for the MCID and PASS were given with the postoperative PROMIS survey. Receiver operator curves were constructed to determine the threshold values for the MCID and PASS. Curves were generated for the study population as well as separate cohorts segregated by median baseline PF or PI scores and preoperative athletic participation. A multivariate post hoc analysis was then constructed to evaluate factors associated with achieving the PASS or MCID.

RESULTS

There were 113 patients (35% male; mean ± SD age, 32.8 ± 12.5 years; body mass index, 25.8 ± 4.8 kg/m), with 60 (53%) reporting preoperative athletic participation. Survey time averaged 77.5 ± 49.2 seconds. Anchor-based MCID values were 5.1 and 10.9 for the PF and PI domains, respectively. PASS thresholds were 51.8 and 51.9 for the PF and PI, respectively. PASS values were not affected by baseline scores, but athletic patients had a higher PASS threshold than did those not participating in a sport (53.1 vs 44.7). MCID values were affected by preoperative baseline scores but were largely independent of sports participation. A post hoc analysis found that 94 (83%) patients attained the MCID PF while 66 (58%) attained the PASS PF. A multivariate nominal logistic regression found that younger patients ( = .01) and athletic patients ( = .003) were more likely to attain the PASS.

CONCLUSION

The PROMIS survey is an efficient metric to evaluate preoperative disability and postoperative function after primary hip arthroscopy for femoroacetabular impingement. The MCID and PASS provide surgeons with threshold values to help determine PROMIS scores that are clinically meaningful to patients, and they can assist with therapeutic decision making as well as expectation setting.