The utility of MMPI subtypes for the prediction of weight loss after bariatric surgery. Minnesota Multiphasic Personality Inventory.

In this paper we report a study designed to improve the ability to predict postoperative weight loss employing methods dictated by the premise that substantial psychological homogeneity is necessary within subsets of patients before similar weight losses can be observed within those subsets. Subjects were 138 women who completed the MMPI prior to undergoing vertical banded gastroplasty. Cluster analysis of the MMPI profiles identified 10 predictive MMPI types. Fifty-six percent of the patients were classified into the 10 types, the remainder were grouped into a residual category. Analysis of covariance revealed that MMPI type accounted for 50 percent of the variance in 12-month weight loss after covarying for initial weight and pre-operative percentage of ideal weight. Variables that added significantly to the prediction of weight loss were age and MMPI scale Pd. In general, the prototypic profiles indicative of the greatest disturbance predicted poor weight loss. In contrast to the 10 MMPI types described in this study, an alternative clustering of patients into fewer groups with much less psychological homogeneity was not predictive of outcome.