Validity of a back pain classification scale for detecting psychological disturbance as measured by the MMPI

Constructed a Back Pain Classification Scale (BPCS) to detect serious psychological disturbance in low back pain patients, validated against the MMPI. One hundred and twenty patients with low back pain were classified as functional or organic on the basis of BPCS scores. The group identified as psychologically disturbed (functional) had significantly higher MMPI elevations on Scales F, HS, D, HY, PD, MF, PA, PT and SC. None of their scale scores was significantly lower than the group identified as organic. T-scores above 70 were present only on Scales 1 and 3, which suggests a high incidence of essentially neurotic disorders in patients classified as functional. The use of the BPCS as a viable alternative to the MMPI in the medical setting was discussed.