Reliability and Validity of Minnesota Multiphasic Personality Inventory-3 (MMPI-3) Scale Scores Among Patients Seeking Spine Surgery

Public Significance Statement Many behavioral health specialists use psychological testing as part of their presurgical psychological evaluation. These data suggest that a new version of the MMPI, the MMPI-3, provides reliable and valid scale scores that can be considered as part of a presurgical evaluation of patients seeking spine surgery. The Minnesota Multiphasic Personality Inventory (MMPI) family of instruments has been commonly used for the evaluation of patients seeking surgical intervention for back pain. A new version of the MMPI, the Minnesota Multiphasic Personality Inventory-3 (MMPI-3), has been released with updated normative data, expanded and revised item content, and updated scales. The purpose of this investigation is to report reliability and validity findings for MMPI-3 scale scores of patients seeking spine surgery. Using a sample of 761 spine surgery candidates (390 men and 371 women), descriptive data, reliability and standard error of measurement, and zero-order correlations using external criteria (self-report and information gathered from a medical record review/clinical interview) were calculated. By and large, men and women produced MMPI-3 scale scores that were similar with a few exceptions. Many reliability estimates and standard errors of measurement were replicable compared to those reported for the MMPI-3 normative sample for scales that yielded adequate range. The scale scores of the MMPI-3 also yielded evidence of good convergent and discriminant validity when correlated with external criteria. Indeed, MMPI-3 scale scores accounted for 2%-15% of incremental variance in data obtained via the clinical interview and medical chart, once other self-report measures were accounted for. Overall, many of the MMPI-3 scale scores used in spine surgery evaluations appear to be reliable and valid.