Cognitive-behavioral classifications of chronic pain: replication and extension of empirically derived patient profiles.

Many attempts have been made to classify patients with chronic pain in order to make sense of a very complex problem and to direct patients towards appropriate treatments for their condition. Unfortunately, these efforts have not been empirically based and have demonstrated limited clinical use. Predominant emphasis has been placed on either biomedical or psychopathological elements of the chronic pain experience with little integration of cognitive-behavioral factors. Turk and Rudy (1988) introduced an empirically derived pain patient taxonomy based on analyses of the Multidimensional Pain Inventory (MPI). The primary purpose of the present study was to replicate this classification system by using different measures for similar constructs in different groups of chronic pain patients. Items designed to measure 4 constructs (activity interference, emotional distress, pain intensity, and perceived support) were collected from 1594 pain patients evaluated at two separate pain treatment facilities. Confirmatory factor analytic results indicated high reliability of the items in measuring these 4 constructs. Replicated clustering techniques demonstrated the robustness of 3 patient profiles across the patient samples. The 3 clusters corresponded remarkably well to the groups initially labeled by Turk and Rudy (1988) as Dysfunctional, Interpersonally Distressed and Adaptive Copers. External validation of the classification system supported replication of the 3 groups and offered further interpretational clarity to the patient profiles. Strong evidence was found for a taxonomy of 3 chronic pain patient groups. Implication for predicting treatment outcome and for future research are discussed.