Factorial validity of the short-form McGill pain questionnaire (SF-MPQ).

Although widely used, there have been few investigations of the factorial validity of the short-form McGill Pain Questionnaire (SF-MPQ; Melzack, 1987). Confirmatory factor analysis was performed on item responses to the SF-MPQ obtained from 188 patients with chronic back pain. Consistent with the original structure proposed by Melzack (1987), results indicated that the SF-MPQ is best represented by a two-factor solution. However, these findings are contrary to results obtained by Burckhardt and Bjelle (1994) who, using their Swedish version of the SF-MPQ, obtained a three-factor solution. Potential explanations for the disparity between the results of the two studies are explored and recommendations for continuing clinical and research applications are offered.