Skip to main content
Key Specialties
Cardiology Diabetology Endocrinology Gastroenterology Geriatrics and Gerontology Gynecology and Obstetrics Hematology Infectious Disease Internal Medicine Nephrology Neurology Oncology Pediatrics Respiratory Medicine Rheumatology Surgery
Congress Coverage
2024 ACC Congress 2023 ESMO Congress 2023 EASD Congress 2023 ERS Congress 2023 ESC Congress
Clinical Collections
Advances in Alzheimer’s

At a glance: The STEP trials

A round-up of the STEP phase 3 clinical trials evaluating semaglutide for weight loss in people with overweight or obesity.
ADVANCED SEARCH
Log in
Top
Health and Quality of Life Outcomes
Published in: Health and Quality of Life Outcomes 1/2014

Open Access 01-12-2014 | Research

Modelling the relationship between the WOMAC osteoarthritis index and EQ-5D

Authors: Allan Wailoo, Monica Hernandez Alava, Antonio Escobar Martinez

Published in: Health and Quality of Life Outcomes | Issue 1/2014

Login to get access

Abstract

Objective

Economic evaluation typically is conducted using health state utilities to estimate treatment benefits. However, such outcomes are often missing from studies of clinical effectiveness. This study aims to bridge that gap by providing appropriate methods to link values from the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) to the EQ-5D utility instrument.

Method

Patients from a large registry of Spanish patients (n = 7072 observations) with knee or hip osteoarthritis who completed both WOMAC and EQ-5D was used. A mixture model approach was used based on distributions bespoke to the EQ-5D UK value set to estimate EQ-5D as a function of WOMAC pain, stiffness and function subscores.

Results

A five class mixture model provides very close fit to the observed data at all levels of disease severity. The overall mean (0.542 vs 0.542), median (0.620 vs 0.636) and the percentage of observations at full health (15 vs 14.8) were very similar between the observed data and the estimated model respectively. Stiffness has limited relationship to EQ-5D, whereas functional disability and pain are strong predictors.

Conclusion

EQ-5D can be reliably estimated from WOMAC subscale scores without any systematic bias using these results.
Appendix
Available only for authorised users
Literature
1.
Bellamy N, Buchanan W, Goldsmith CH, Campbell J, Stitt L: Validation study of WOMAC: a health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis in the knee or the hip. J Rheumatol 1988, 30: 167–178.
2.
Brazier J, Yang Y, Tsuchiya A: A review of studies mapping (or cross walking) non-preference based measures of health to generic preference-based measures. Eur J Health Econ 2010, 11: 21525.CrossRef
3.
Hernandez Alava M, Wailoo A, Wolfe F, Michaud K: The relationship between EQ-5D, HAQ and pain in patients with rheumatoid arthritis. Rheumatology 2013. doi:10.1093/rheumatology/kes400
4.
Marshall D, Pericak D, Grootendorst P, Gooch K, Faris P, Frank C, Bellamy N, Torrance G, Feeny D: Validation of a prediction model to estimate health utilities index mark 3 utility scores fromWOMAC index scores in patients with osteoarthritis of the Hip. Value Health 2008, 11(3):470–477. 10.1111/j.1524-4733.2007.00258.xCrossRefPubMed
5.
Barton G, Sach T, Jenkinson C, Avery A, Doherty M, Muir K: Do estimates of cost-utility based on the EQ-5D differ from those based on the mapping of utility scores? Health Qual Life Outcomes 2008, 6(1):51. 10.1186/1477-7525-6-51PubMedCentralCrossRefPubMed
6.
Xie F, Pullenayegum EM, Li S, Hopkins R, Thumboo J, Lo N: Use of a disease-specific instrument in economic evaluations: mapping WOMAC onto the EQ-5D utility index. Value Health 2010, 13(8):873–878. 10.1111/j.1524-4733.2010.00770.xCrossRefPubMed
7.
Grootendorst P, Marshall D, Pericak D, Bellamy N, Feeny D, Torrance GW: A model to estimate health utilities index mark 3Utility scores from WOMAC index scores in patients with osteoarthritis of the knee. J Rheumatol 2007, 34: 534–542.PubMed
8.
Hernandez Alava M, Wailoo AJ, Ara R: Tails from the peak district: adjusted limited dependent variable mixture models of EQ-5D health state utility values. Value Health 2012. doi:10.1016/j.jval.2011.12.014
9.
Hernandez Alava M, Wailoo A, Wolfe F, Michaud K: “A comparison of direct and indirect methods for the estimation of health utilities from clinical outcomes”. Med Decis Mak in press
10.
11.
Mitchell PM, Roberts TE, Barton PM, Pollard BS, Coast J: Predicting the ICECAP-O capability index from the WOMAC osteoarthritis index: is mapping onto capability from condition-specific health status questionnaires feasible? Med Decis Mak 2013. doi:10.1177/0272989X12475092
Metadata
Title
Modelling the relationship between the WOMAC osteoarthritis index and EQ-5D
Authors
Allan Wailoo
Monica Hernandez Alava
Antonio Escobar Martinez
Publication date
01-12-2014
Publisher
BioMed Central
Published in
Health and Quality of Life Outcomes / Issue 1/2014
Electronic ISSN: 1477-7525
DOI
https://doi.org/10.1186/1477-7525-12-37

Other articles of this Issue 1/2014

Health and Quality of Life Outcomes 1/2014 Go to the issue

Review

Patient reports of the outcomes of treatment: a structured review of approaches

Review

Interviewing to develop Patient-Reported Outcome (PRO) measures for clinical research: eliciting patients’ experience

Research

Assessment of sleep in patients with fibromyalgia: qualitative development of the fibromyalgia sleep diary

Research

Behavioural profile and human adaptation of survivors after radical cystectomy and ileal conduit

Research

Violations of local stochastic independence exaggerate scalability in Mokken scaling analysis of the Chinese Mandarin SF-36

Research

Psychosocial work conditions and quality of life among primary health care employees: a cross sectional study