Discriminant Function Analysis of the MC Gill Pain Questionnaire

Abstract

The performance on the McGill Pain Questionnaire was compared with an alternate version of 16 subcategories of adjectives in distinguishing among three groups of patients with pain. Both versions were administered to (a) primiparae experiencing postepisiotomy pain (n = 60); (b) outpatients attending a rheumatology clinic (n = 60); (c) inpatients having undergone wisdom tooth extraction (n = 60). The order of administration was balanced, so that within each group all 60 patients received both forms of the questionnaire. A number of forms of discriminant function analysis were executed to examine the external validity of the two questionnaire formats in distinguishing among the three patient groups. There were few differences between the two versions, with sensory subcategories loading higher on discriminant functions than affective and evaluative subcategories.