MINNESOTA MULTIPHASIC PERSONALITY-INVENTORY (MMPI) CLUSTER GROUPS AMONG CHRONICALLY ILL PATIENTS - RELATIONSHIP TO ILLNESS ADJUSTMENT AND TREATMENT OUTCOME

Cluster analysis of the MMPI has been utilized widely in the chronic l ow back pain literature to try to identify reliable patient subtypes p redictive of treatment outcome. We extended this methodology to patien ts with heterogeneous chronic medical conditions by replicating protot ypic MMPI cluster group profiles and by relating cluster groups to cli nical baseline and outcome data. Subjects were two independent samples (n = 254 and n = 263) of chronically ill patients admitted to an inpa tient medicine/psychiatry unit. Using a four-cluster solution, similar cluster profile groups were replicated in both samples. Consistent di fferences emerged between cluster groups on functional impairment, psy chiatric diagnoses, depression, and psychosomatic symptoms. Cluster gr oup membership also predicted changes in functional impairment and dep ression six months after treatment. Results are discussed in terms of similarities between chronic low back pain and chronic illness and tai loring treatment to different patient types.