We argue that the conflicting results reported in previous studies examining the factor structure of the McGill Pain Questionnaire Pain Rating Index (PRI) can be explained by differences in the patient samples and statistical analyses used across studies. In an effort to clarify the factor structure of the PRI, 3 different factor models were compared using confirmatory factor analysis in 2 samples of low-back pain patients (N = 1372) and in a third sample of patients suffering from other chronic pain problems (N = 423). A 4-factor model, similar to those obtained in previous studies where multiple criteria were used to determine the number of factors extracted, best explained covariation among PRI subclasses. However, relatively high interfactor correlations (approximately two-thirds of the variance explained by the best fitting factor structure was common variance) cast doubt on the discriminant validity of PRI subscales; examination of relationships between the PRI and MMPI subscales also failed to provide evidence of the discriminant validity or clinical utility of PRI subscales. Reducing the information from the 10 PRI sensory subclasses to a single subscale score may seriously limit the usefulness of the PRI. Alternate methods of using PRI data are suggested.

SYNOPSISTwo hypotheses were tested in this study: (1) that a short course of cognitive behavioral therapy (CBT) is effective in the treatment of chronic headache; and (2) that group CT is as effective as individually administered CBT. Twenty‐two chronic headache sufferers were randomly assigned to one of three treatment conditions: group administered CBT, individually administered CBT, or no treatment (wait list) control. Wait list subjects ultimately received treatment identical to that offered to subjects in the group treatment condition. Treatment outcome measures included the Brief Symptom Inventory, the McGill Pain Questionnaire, and several measures calculated from self‐monitoring data. Tentative support was found for the hypothesis that CBT as provided in this study is effective in the treatment of chronic headache. There was no evidence that group versus individually treated subjects differed significantly on any of the measures used, although the small N and large variance among subjects limit us to preliminary conclusions for our findings. Clinical implications and suggestions for future research are discussed.

Cognitive behavioural treatment for chronic pain was individually tailored based on pre-treatment assessment of the subjective pain experience of each patient. Eight chronic pain patients completed the individualized treatment program which consisted of relaxation techniques, hypnotic deepening strategies, a relabeling hierarchy based upon pain descriptors, positive self-statements, didactic information, and cognitive-restructuring techniques. Patients self-monitored their pain during a two week pre-treatment baseline period, during the eight weeks of treatment and for one week post-treatment. Additional treatment outcome measures were also taken. Compared to baseline data, patients reported positive changes on many of the treatment outcome criteria, including McGill Pain Questionnaire indices, reduction in the number of hours spent in pain, and follow-up questionnaire responses. Treatment outcome measures collected at one week, six months, and 15 months post-treatment all suggested positive treatment gains. The greatest gains were reported at the six month post-treatment assessment suggesting a generalization or practice component to the therapy. Additionally, patients with constant pain were found more refractory to treatment than patients with intermittent pain.

1Department of Psychology, The Ohio State University, Columbus, OH 43210, USA 2Department of Physical Medicine, The Ohio State University, Columbus, OH 43210, USA