Psychometric properties of patient-reported outcome measures for hip arthroscopic surgery.

BACKGROUND: Patient-reported outcomes (PROs) are considered the gold standard when evaluating outcomes in a surgical population. While the psychometric properties of some PROs have been tested, the properties of newer PROs in patients undergoing hip arthroscopic surgery remain somewhat unknown.

PURPOSE: To evaluate the reliability, validity, responsiveness, and interpretability of 5 PROs (Copenhagen Hip and Groin Outcome Score [HAGOS], Hip Disability and Osteoarthritis Outcome Score [HOOS], Hip Outcome Score [HOS], International Hip Outcome Tool [iHOT-33], and Modified Harris Hip Score [MHHS]) in a population undergoing hip arthroscopic surgery and also to provide a recommendation of the best PROs in patients undergoing hip arthroscopic surgery.

STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2.

METHODS: Study participants were adults (mean age, 37 ± 11 years) who had undergone hip arthroscopic surgery 12 to 24 months previously and pain-free, healthy age-matched controls (mean age, 35 ± 11 years). Baseline characteristics including age, height, weight, waist girth, physical activity, and occupation were collected for both groups. The hip arthroscopic surgery group completed the 5 PRO questionnaires on 3 occasions, while the healthy control group completed the PRO questionnaires on 1 occasion. The reliability (test-retest reliability [intraclass correlation coefficient, or ICC] and minimal detectable change [MDC]), validity (construct validity, ability to detect a difference between groups, acceptability including floor and ceiling effects), responsiveness, and interpretability (minimal important change [MIC]) of each measure were calculated.

RESULTS: The test-retest reliability of PROs was excellent (ICC, 0.91-0.97), with an MDC of <20%. The HOOS, HAGOS, and iHOT-33 had acceptable content validity. All PROs demonstrated construct validity and were able to detect a difference between the hip arthroscopic surgery and control groups. No measures demonstrated a floor effect; however, the MHHS and subscales relating to activities of daily living of the HOOS, HOS, and HAGOS demonstrated a ceiling effect. The HOOS, iHOT-33, and MHHS demonstrated adequate responsiveness, and the MIC for all measures was <11 points of a possible 100 points.

CONCLUSION: The PROs of the HOOS and iHOT-33 demonstrate psychometric properties that may enable researchers and clinicians to use them with confidence in a population undergoing hip arthroscopic surgery. The psychometric properties of the MHHS, HOS, and some subscales of the HAGOS are reduced, and these PROs may be less valuable in this group.