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.