Hip disability and osteoarthritis outcome score (HOOS) – validity and responsiveness in total hip replacement

TLDR

The HOOS incorporates all WOMAC LK 3.0 items unchanged. The study aimed to assess whether physical functions typical of younger patients matter for older adults and to develop a hip osteoarthritis outcome measure with greater responsiveness than WOMAC LK 3.0. A 40‑item HOOS questionnaire covering pain, symptoms, ADL, sport/recreation, and quality of life was administered pre‑operatively and at six months to 90 primary hip osteoarthritis patients (mean age 71.5) scheduled for total hip replacement. The HOOS 2.0 met validity and responsiveness criteria, outperforming WOMAC in pain and symptom subscales, with added sport/recreation and quality‑of‑life subscales also highly responsive, especially in patients under 66 years old.

Abstract

The aim of the study was to evaluate if physical functions usually associated with a younger population were of importance for an older population, and to construct an outcome measure for hip osteoarthritis with improved responsiveness compared to the Western Ontario McMaster osteoarthritis score (WOMAC LK 3.0). A 40 item questionnaire (hip disability and osteoarthritis outcome score, HOOS) was constructed to assess patient-relevant outcomes in five separate subscales (pain, symptoms, activity of daily living, sport and recreation function and hip related quality of life). The HOOS contains all WOMAC LK 3.0 questions in unchanged form. The HOOS was distributed to 90 patients with primary hip osteoarthritis (mean age 71.5, range 49–85, 41 females) assigned for total hip replacement for osteoarthritis preoperatively and at six months follow-up. The HOOS met set criteria of validity and responsiveness. It was more responsive than WOMAC regarding the subscales pain (SRM 2.11 vs. 1.83) and other symptoms (SRM 1.83 vs. 1.28). The responsiveness (SRM) for the two added subscales sport and recreation and quality of life were 1.29 and 1.65, respectively. Patients ≤ 66 years of age (range 49–66) reported higher responsiveness in all five subscales than patients >66 years of age (range 67–85) (Pain SRM 2.60 vs. 1.97, other symptoms SRM 3.0 vs. 1.60, activity of daily living SRM 2.51 vs. 1.52, sport and recreation function SRM 1.53 vs. 1.21 and hip related quality of life SRM 1.95 vs. 1.57). The HOOS 2.0 appears to be useful for the evaluation of patient-relevant outcome after THR and is more responsive than the WOMAC LK 3.0. The added subscales sport and recreation function and hip related quality of life were highly responsive for this group of patients, with the responsiveness being highest for those younger than 66.