The use of the Minnesota Multiphasic Personality Inventory with low back pain patients

The MMPI was administered to 36 male low back pain patients at the Seattle Veterans Administration Hospital. The patients were divided into three groups of 12 each. The organic group contained patients who had an organic basis for their pain. The functional group contained patients who had no organic basis for their pain. The mixed group contained patients who had some organic basis for their pain, but one that was thought to be insufficient to account for the pain they were reporting. The mixed and functional groups differed significantly from the organic group on the Hs, Hy, Pt, Sc, Hy-O, D-O, and DOR scales. The mixed and functional groups differ significantly from each other only on the Hy-O scale. The special low back pain scales of Lb and DOR were found to have little utility when used separately. When used in conjunction, however, the scales discriminated correctly 75% of the time.