Multi-Modal Examination of Psychological and Interpersonal Distinctions Among MPI Coping Clusters: A Preliminary Study

Abstract

The Multidimensional Pain Inventory (MPI) is a widely used instrument to characterize distinct psychosocial subgroups of patients with chronic pain: Adaptive (AC), Dysfunctional (DYS), and Interpersonally Distressed (ID). To date, several questions remain about the validity and distinctiveness of the patient clusters, and continued scientific attention has strongly been recommended. It is unclear if AC patients experience better adjustment or merely present themselves favorably. Moreover, differences in psychological distress and interpersonal relations between DYS and ID patients are equivocal. The present study is the first to utilize comprehensive informant ratings to extend prior validity research on the MPI. We employed a multimodal methodology consisting of patient self-report, parallel informant ratings, and behavioral measures. Ninety-nine patients with chronic pain, their partners, and providers participated. They completed measures of patients' psychological distress and social relations. We also systematically observed patients' pain behavior. Results provided strong support for the validity of the AC cluster in that patients' positive adaptation was reliably corroborated by informants. The differentiating characteristics between the 2 maladaptive clusters, however, remain elusive. We found evidence that DYS patients' distress appeared to be illness specific rather than generalized; however, both clusters were equally associated with social distress and partner/caregiver burden. An adaptive style of coping with chronic pain is reliably recognized by patients' partners and healthcare providers. Differences between a dysfunctional and an interpersonally distressed coping style, however, remain unclear. Patients with a dysfunctional style appear more distressed by their illness but both styles are characterized by social difficulties.