A further look at validity of the MMPI with low back patients

Tested the accuracy of the MMPI for two separate predictions: organic vs. functional back disorder, and appropriate vs. inappropriate disability (N = 123). Consistent with other reports, the Low Back and Dorsal scales did not improve upon chance prediction. However, disability was predicted with a high degree of accuracy by Hypochondriasis and Hysteria, which suggested that precedence should be given to these two scales. Because organically based pain and severe psychological symptomatology were not mutually exclusive, the error rate was high when the MMPI was used to predict organicity. Clinicians therefore are urged to avoid predicting whether a physical basis for pain exists and to focus primarily on the psychological aspects of the disability.