Prognostic Nutritional Index: Its Usefulness as a Predictor of Clinical Course

It is of great consequence to be able to predict an individual's risk of clinical complication during hospitalization. The Prognostic Nutritional Index (PNI), which is based upon one's nutritional status, is a method that has been developed for this purpose. The PNI equation is comprised of the following indicators of nutritional status: serum albumin level, serum transferrin level, triceps skinfold thickness, and delayed hypersensitivity. This study was designed to evaluate the usefulness of PNI in predicting clinical course.

The sample was composed of 328 subjects who had been admitted to medical or surgical services of the Veterans Administration Medical Center, Johnson City, Tennessee. The criterion for inclusion in the study was complete nutritional assessment between 1978 and 1981. A PNI was calculated for each subject. Using a retrospective review of subjects' medical records, extent and type of complications was determined. The measure of complication score used in the study could range from 0 - 28.

The mean for the PNI was approximately 45%, indicating that, on average, the risk of clinical complications in this sample was 45% or in the intermediate (40-50%) category. This was the equivalent of a complication score of 8. There was a significant (p < 0.05), positive correlation between PNI and complication score. A positive multiple correlation was found between complication score and the block of variables upon which PNI is based, specifically serum albumin level, serum transferrin level, triceps skinfold thickness, and delayed hypersensitivity. These results support a direct relationship between nutritional status and clinical course. This provides documentation for the usefulness of PNI as a technique for predicting clinical complications based upon nutritional assessment.