WOMAC pain subscale

Method

Western Ontario and McMaster Universities Osteoarthritis Index pain subscale, 5 items, administered in Likert (0-20) or visual-analogue format. The format and whether the score was normalised to 0-100 are recorded on the edge.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

The WOMAC total index contains this subscale: pain is 5 of 24 items and is outweighed by the 17-item function subscale, so reporting a subscale as the total, or the reverse, changes both the magnitude and the achievable range of the effect. Also distinct from a standalone visual analogue scale pain score in millimetres, which is a single item on a different range, and from the pooled osteoarthritis pain SMD, which has no physical unit and is not back-convertible to these points. Carrying this and the WOMAC total from one trial double-counts one questionnaire administration.