Whats womac

The short version: WOMAC is a 24-question survey that measures pain, stiffness, and physical function in knee and hip arthritis. It is the most widely used patient-reported outcome in osteoarthritis research, but it is a subjective score, not a measure of joint health.

WOMAC stands for the Western Ontario and McMaster Universities Osteoarthritis Index [1]. It asks patients to rate 24 items on a 0-to-4 scale: 5 questions about pain, 2 about stiffness, and 17 about physical function. Lower scores mean less pain and better function. A total score of 39 or higher on a 0-to-100 scale indicates severe arthritis [1]. It has been validated across populations, including Asian patients in Singapore, where it showed good internal consistency and test-retest reliability [2]. A short-form version with just 7 function items also performs well, with a Cronbach's alpha of 0.95 and strong agreement with the full version [5].

The key limitation is that WOMAC is entirely subjective. It measures what a person reports, not what is happening inside the joint. A person who feels better after a treatment may report lower WOMAC scores even if their cartilage is still degrading. The evidence shows that WOMAC scores correlate poorly with structural changes seen on X-rays or ultrasound [3, 4]. Pain severity, obesity, and psychological factors like helplessness predict disability far better than radiographic damage does [4]. Anxiety and fear-avoidance beliefs are also linked to worse self-reported function on WOMAC, even when performance-based tests like the Timed Up and Go show no such relationship [6].

For the reader asking about knee pain, WOMAC is useful as a tracking tool for your own symptoms over time, but it is not a diagnostic test and it does not tell you whether your joint is actually getting worse. A treatment that improves your WOMAC score by 10 points may be helping you feel better, or it may be a placebo effect captured by a subjective scale. The evidence base on WOMAC is well-established, but it is a measure of perception, not pathology.

My call: WOMAC is a valid and reliable symptom questionnaire, but it measures subjective function, not joint health. Confidence: high for what it measures, moderate for whether it captures what matters most.