Clusters of Financially Incentivized Chronic Pain Patients Using the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF)
The Minnesota Multiphasic Personality Inventory (MMPI)-2 Restructured Form (MMPI-2-RF) has been shown to have clinical utility in the assessment of individuals with chronic pain (e.g., predicting surgical outcomes). The purpose of this study was to explore the ability of the MMPI-2-RF Validity Scales in profiling patients with chronic pain who had external financial incentive (e.g., workers’ compensation claims) and determine the associations between Validity Scale response patterns and important outcomes. Cluster analysis identified 2 similarly sized clusters of patients with very different MMPI-2-RF profiles. Cluster 1 was characterized by valid responding and showed mean elevations on the somatic and low positive emotion Restructured Clinical scales. Cluster 2 was characterized by patients overreporting on the MMPI-2-RF Validity Scales, who also demonstrated elevations on 7 of the 9 RC scales. Cluster membership was differentially associated with clinical variables: patients in Cluster 2 had greater self-reported pain and disability, were less likely to have spine-related findings on imaging and were more likely to be classified as probable or definite malingerers. These results support the utility of the MMPI-2-RF Validity scales in distinguishing between credible and noncredible responses from patients with chronic pain seen within a medico-legal context.