A COMPARISON BETWEEN THE MINNESOTA MULTIPHASIC PERSONALITY-INVENTORY AND THE MENSANA-CLINIC BACK PAIN TEST FOR VALIDATING THE COMPLAINT OF CHRONIC BACK PAIN

  • 1 February 1988
    • journal article
    • research article
    • Vol. 30  (2) , 98-102
Abstract
Reports on the efficiency of the Minnesota Multiphasic Personality Inventory (MMPI) for selecting patients with valid complaints of pain have been equivocal. The Mensana Clinic Back Pain Test (MPT) was able to predict, with some degree of success, patients who had a definite organic pathologic condition. However, the MMPI measures personality traits, whereas the MPT measures the impact of pain on a patient''s life. To determine which of the two tests would be a better predictor of actual physical abnormalities, and hence valid pain complaints, a comparison was undertaken between the two tests. The charts of 83 patients admitted to the Neurosurgery Service of John Hopkins Hospital with complaints of back pain were assessed. MMPI test results, as well as test results for the MPT, were compared to the pressure or absence of pathologic condition on electromyography, nerve conduction velocity studies, thermography, myelogram, or computerized axial tomography scan. The MPT had a correlation factor of -.59700, that was significant as P = .000005. Of the 52 patients scoring 17 points or less on the MPT, 85% had objective physical abnormalities, considered moderate or severe by blind review. Of the 31 patients scoring 18 points or greater on the MPT, only 26% had objective physical findings that were considerd moderate or severe. Only the F scale (faking badly) of the MMPI correlated with objective physical abnormalities (r = .21340, P < .033). However, 60% of the patients with T scores of less than 70 on the F scale had objective findings, whereas 75% of patients with T scores greater than 70 had objective physical findings. Other MMPI scales did not correlate. Therefore, the MMPI cannot be considered a valid test for predicting the presence or absence of physical abnormalities, whereas the MPT could do so with greater reliability and validity. We conclude that the presence or absence of physical abnormalities occurs as an independent variable from personality traits, and the MPT is a better predictor of the validity of the complaint of pain than the MMPI.