Scaling the affective domain of pain: a study of the dimensionality of verbal descriptors.

This study evaluated the multidimensional structure of affective verbal descriptors and investigated individual differences in the scaling of the descriptors. Patients with chronic low back pain, chronic headache and rheumatoid arthritis (25 per group) and 25 control subjects, matched for age and sex, made similarity judgements of a set of 12 verbal descriptors, e.g., awful, miserable. They also completed the Coping Strategies Questionnaire, the Hospital Anxiety and Depression Scale, McGill Pain Questionnaire Short Form, and a measure of verbal intelligence. The similarity data were subjected to individual differences multidimensional scaling (ALSCAL) and the resulting subject weights were related to group membership and the questionnaire data. The multidimensional nature of affective descriptors was confirmed. A 4-dimensional solution was identified: the first 3 dimensions were comparable with previous findings and labeled Tolerability, Focus of Attention and Minor Emotional Reaction. The 4th dimension was enigmatic and attributable to the back pain group. There were significant differences between the groups in their weighting of the dimensions and in their self-reported coping strategies. The results are discussed with reference to an earlier study and the degree of consistency across the studies is noted. Implications of the results for the conceptualisation and measurement of the affective domain of pain report are outlined.