Confirmatory Factor Analysis of the Hip Disability and Osteoarthritis Outcome Score (HOOS) and Associated Sub-scales.
Emilie N Miley, Madeline P Casanova, Scott W Cheatham and 3 others
PMID 36793579WHAT IT FOUND
The 40-item HOOS and HOOS-12 failed statistical structure tests, suggesting items overlap too much to measure distinct problems.
The shorter HOOS-JR showed better structure and validly distinguished hip pathology from healthy states, making it more reliable for screening hip dysfunction in active populations.
Key findings
01The original 40-item HOOS and the 12-item HOOS-12 did not meet recommended statistical fit criteria, indicating potential item redundancy and an inability to measure unique constructs.
02The 6-item HOOS-JR demonstrated stronger model fit and passed invariance testing, showing it validly identifies higher dysfunction in those with hip pathology compared to healthy individuals.
03The 5-item HOOS-PS met some fit criteria but failed invariance testing across injury types, meaning score differences between hip pathology and healthy groups cannot be assumed to be true clinical differences.
STILL TO COME
How it was doneWhat they foundWhat it means for PTsWhat it means for OTs
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What it does not show
The sample was predominantly healthy (69%) and physically active, with very few participants diagnosed with hip osteoarthritis or having undergone total hip arthroplasty. Invariance testing for the HOOS-JR and HOOS-PS used small subgroups (n=48 for hip pathology), which may affect statistical power. Participants completed the full 40-item HOOS, so short-form scores were derived from the same response set, potentially influencing results compared to administering the short forms independently. The study was cross-sectional, so it could not assess test-retest reliability, responsiveness, or longitudinal invariance.
Declared interests
The authors declared no conflicts of interest. The study was not funded by a commercial entity; recruitment involved social media and ResearchMatch.
The easy way to misread this
Do not assume the HOOS-PS is valid for comparing patients with hip pathology to healthy controls. It failed invariance testing for injury subgroups, meaning score differences may reflect measurement error rather than true clinical differences.