Validity of MMPI-2 profiles in chronic back pain patients: Differences in path models of coping and somatization

Objective: To show clinical utility and empirical validity of Minnesota Mul tiphasic Personality Inventory-2 (MMPI-2) chronic pain patient subgroups by identification of differential multivariate relationships across groups. Method: This study used structural equation modeling to test cognitive copi ng strategies and somatization as mediator variables in path models with pa in severity and depression used as exogenous (independent) variables and pa tient's activity level as the final endogenous (dependent) variable, across MMPI-2 profiles. Results: Hierarchical cluster analysis, performed on a sample of 569 chroni c low back patients, resulted in four cluster profiles identifiable as thos e found in previous work with the MMPI-2 (within normal limits, V-type, neu rotic triad, and depressed-pathological). Somatization mediated the relatio nship between depression and activity level for the neurotic triad group bu t not the other three groups. A positive linear relationship was found betw een somatization and depression for the within normal limits, neurotic tria d, and depressed-pathological groups, whereas their linear association was negative for the V-type group. Cognitive coping strategies mediated the rel ationship between depression and activity level for the within normal Limit s group. In addition, cognitive coping was predictive of activity level for the within normal limits, V-type, and neurotic triad groups but not for th e depressed-pathological group. Conclusion: Consistent with previous cluster analytic studies, this study r eplicated four MMPI-2 cluster profile groups in chronic pain patients. Thes e results have also shown that several multivariate relationships between v ariables are different across MMPI-2 groups, providing evidence for the val idity for these MMPI-2 subgroups.