A standardized evaluation of psychosocial factors in chronic pain.

A number of psychosocial factors are generally considered to be important in exacerbating and maintaining chronic pain problems. However, standardized and reliable methods of evaluating these factors are needed. We have developed such an evaluation system, called the Psychosocial Pain Inventory (PSPI), and have obtained normative data from a large sample of chronic pain patients. Scores on the PSPI were approximately normally distributed and had good inter-rater reliability. Patients with high PSPI scores were more likely to be considered exaggerating their symptoms during their physical examinations, but they did not show less evidence of an organic basis for pain. Significant correlations were obtained between PSPI scores and some measures from the McGill Pain Questionnaire, but scores on the PSPI were essentially unrelated to personality disturbance as measured by the Minnesota Multiphasic Personality Inventory (MMPI). The PSPI and MMPI appear to provide different types of information that can be used in a complementary way in evaluating pain patients. Results of a small pilot study suggest that high scores on the PSPI predict poor response to medical treatment for pain.