Psychometric Properties of Patient-Reported Outcome Measures for Periacetabular Osteotomy

Abstract

Background: Appropriate patient-reported outcome measures are paramount to determine the clinical relevance of change experienced by patients after a surgical procedure. The purpose of this study was to evaluate the psychometric properties of 3 patient-reported outcome measures (Hip disability and Osteoarthritis Outcome Score [HOOS], modified Harris hip score, and Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]) in a large population of patients treated with periacetabular osteotomy for symptomatic developmental dysplasia of the hip. Methods: Patients who underwent a periacetabular osteotomy for acetabular dysplasia between October 2011 and October 2016 completed multiple questionnaires preoperatively and at the 1-year follow-up. Internal consistency for subscores was evaluated with the Cronbach alpha. Validity was assessed against the Short Form-12. Interpretability included the calculation of the distribution of scores, floor and ceiling effects, and the minimal clinically important difference. Responsiveness was assessed by correlating the score changes with the Global Perceived Effect score. Results: Of 294 patients, 246 (84%) were female. The median age was 21 years (interquartile range, 17 to 29 years). All WOMAC and HOOS subscores demonstrated adequate internal consistency, and none of the modified Harris hip score components did. All scores except the WOMAC stiffness score exhibited adequate validity and interpretability, with no floor and ceiling effects over 15%. For the HOOS subscores, the minimal clinically important difference was 10.3 for pain, 10.2 for symptoms, 12.6 for sports and recreation, 11.2 for quality of life, and 10.8 for activities of daily living. The minimal clinically important difference for the modified Harris hip score was 7.4. For the WOMAC subscores, the minimal clinically important difference was 10.8 for pain, 12.9 for stiffness, 10.8 for physical, and 10.4 for total. All scores demonstrated adequate responsiveness. Conclusions: The HOOS, WOMAC, and modified Harris hip score have adequate psychometric properties for use in patients undergoing periacetabular osteotomy, with minor shortcomings. Among the scores analyzed, the HOOS appears to be the most appropriate measure of patient-reported outcome in patients undergoing periacetabular osteotomy. Clinical Relevance: By establishing the psychometric properties of patient-reported outcome measures for periacetabular osteotomy, this study enables a more informed choice of measures for clinical practice and research. The estimated minimal clinically important difference values will facilitate understanding the importance of change in patient-reported outcomes after a surgical procedure in a clinical setting and sample size calculation for further studies.

Assessment of Disability Related to Hip Dysplasia Using Objective Measures of Physical Performance

“…Our participants' scores on PRO testing align with previously reported preoperative hip pain and function measures in patients with dysplasia before PAO. Wasko et al 37 observed a preoperative HOOS Pain score of 54.4 ± 20.7 and mHHS of 60.0 ± 14.8 in 294 patients. In 336 patients (420 hips), Livermore et al 19 reported PROMIS PF adjusted mean scores of 52.3, 47.3, and 51.0 for mild, moderate, and severe dysplasia, respectively, before surgery.…”

“…Previous studies have observed that these patients demonstrate decreased walking speed 33 or an abductor lurch or limp 27 and report pain and impairment in physical function including both activities of daily living and sport-specific testing on patient-reported outcome (PRO) instruments. 37 It is unknown how these perceived deficits objectively limit patients' ability to perform more physically demanding tasks requiring hip flexion, balance, and strength; the literature on hip dysplasia is particularly sparse compared with anterior cruciate ligament deficiency or FAI, for which excellent data on a variety of athletic and squatting maneuvers exist. 1,3,26 As we continue to explore ways to maximize results from treatment for dysplasia with periacetabular osteotomy (PAO), 9 arthroscopy, and/or other osteotomies, means of quantifying physical function both before and after surgery are critically important.…”

Measures of Hip Function and Symptoms

“…The modified HHS had reported ceiling effects of 27.5% . In a population of 294 patients who underwent periacetabular osteotomy, the modified HHS had reported ceiling effects of 1% .…”

“…The modified HHS has been compared with the 12‐item Short Form Health Survey (SF‐12) physical and mental subscale for validity and has been shown to have poor correlation with the mental subscale but strong correlation with the physical subscale .…”

“…In a study of 335 total hip arthroplasties (THAs), the HHS was found to be responsive to pain and function at the 6‐month postoperative follow‐up but weak at the 2‐year follow‐up . In a study of 293 periacetabular osteotomies, the modified HHS was found to be adequately responsive .…”