Population-based normative values for the Western Ontario and McMaster (WOMAC) Osteoarthritis Index: part I

Abstract

Objectives: To develop population-based age- and gender-specific normative values for the pain, stiffness, and physical function subscales of the WOMAC Index for benchmarking applications.

Methods: A scannable survey questionnaire capable of capturing WOMAC Index data and demographic information was developed, pretested, and distributed to a stratified random sample of 36,000 members of the Australian general public generated by the Australian Electoral Commission.

Results: Age- and gender-specific WOMAC normative values were estimated based on approximately 7300 subjects. Age-related differences were noted in all 3 WOMAC subscales. In general, pain, stiffness, and difficulty with physical function percentiles increased with age.

Conclusions: WOMAC normative values provide opportunity for benchmarking the health status of individuals with hip and knee osteoarthritis against their age- and gender-matched peers in the general population. These normative values provide unique opportunities for using the WOMAC Index in benchmarking applications in both clinical practice and research.