Article Text

Download PDFPDF
Using patients’ and rheumatologists’ opinions to specify a short form of the WOMAC function subscale
  1. F Tubach1,
  2. G Baron1,
  3. B Falissard2,
  4. I Logeart3,
  5. M Dougados4,
  6. N Bellamy5,
  7. P Ravaud1
  1. 1Département d’Epidémiologie, Biostatistique et Recherche Clinique, Groupe Hospitalier Bichat-Claude Bernard (Assistance Publique – Hôpitaux de Paris), Faculté Xavier Bichat (Université Paris 7), Paris, France
  2. 2Faculté Paris XI, Département de santé publique, Hôpital Paul Brousse (Assistance Publique – Hôpitaux de Paris), Villejuif, France
  3. 3Merck Sharp & Dohme, Chibret Laboratories, Paris, France
  4. 4Service de Rhumatologie B, Hôpital Cochin (Assistance Publique – Hôpitaux de Paris), Faculté Paris V, Paris, France
  5. 5CONROD, Faculty of Health Sciences, The University of Queensland, Brisbane, Queensland, Australia
  1. Correspondence to:
    Dr Florence Tubach
    Département d’Epidémiologie, Biostatistique et Recherche Clinique, INSERM E0357, Hôpital Bichat, 46 rue Henri Huchard, 75018 Paris, France; florence.tubachbch.ap-hop-paris.fr

Abstract

Background: The WOMAC (Western Ontario and McMaster Universities) function subscale is widely used in clinical trials of hip and knee osteoarthritis. Reducing the number of items of the subscale would enhance efficiency and compliance, particularly for use in clinical practice applications.

Objective: To develop a short form of the WOMAC function subscale based on patients’ and experts’ opinions (WOMAC function short form).

Methods: WOMAC function subscale data (Likert version) were obtained from 1218 outpatients with painful hip or knee osteoarthritis. These patients and their rheumatologists selected the five items that they considered most in need of improvement. The rheumatologists were asked to select the five items for which patients in general are the most impaired. Items that were least important to patients and experts, those with a high proportion of missing data, and those with a response distribution showing a floor or ceiling response were excluded, along with one of a pair of items with a correlation coefficient >0.75.

Results: The WOMAC function short form included items 1, 2, 3, 6, 7, 8, 9, and 15 of the long form. The short form did not differ substantially from the long form in responsiveness (standardised response mean of 0.84 v 0.80).

Conclusions: A short form of the WOMAC function subscale was developed according to the views of patients and rheumatologists, based on the responses of 1218 patients and 399 rheumatologists. The clinical relevance and applicability of this WOMAC function subscale short form require further evaluation.

  • ICC, intraclass correlation coefficient
  • SRM, standardised response mean
  • WOMAC, Western Ontario and McMaster Universities osteoarthritis index
  • osteoarthritis
  • hip
  • knee
  • treatment outcome

Statistics from Altmetric.com

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Footnotes