A cluster analysis of the multidimensional pain inventory

Seventy-nine patients with chronic headaches of diverse causes, recruited from a headache clinic's biofeedback facility, were administered the Multidimensional Pain Inventory (MPI) for measuring the cognitive, behavioral, and affective dimensions of pain. Using the statistical technique of cluster analysis to organize the results, three clusters emerged, and were similar in their characteristics to those named "Dysfunctional", "Interpersonally Distressed", and "Adaptive Coper" by other authors who had applied the Inventory and the cluster analysis technique to other populations (one population containing heterogenous groups of chronic pain patients, and another population of patients suffering from "temporomandibular joint disorders". Additional analyses of our results confirmed that the three groups were distinct from one another; and that age, sex, duration of complaint, and diagnosis, were not factors in the formation of the groups. Our results suggest that the MPI is a valid measure of the cognitive, behavioral and affective aspects of pain. Rather than apply a similar intervention program to all headache patients, it might be more effective to tailor treatment to the variations in these aspects exhibited by patients in the three different clusters.