Jeffrey P. Baker

THE diagnosis of protein-calorie malnutrition is often based on objective measurements of nutritional status,1 including assessments of hepatic secretory proteins (serum albumin and serum transferrin), anthropometric evaluation, creatinine-height index, and determination of cell-mediated immunity. Although these indicators are epidemiologically useful and correlate with morbidity and mortality,2 3 4 5 6 no single measurement is of consistent value in individual patients.nutritional status may also be assessed by clinical examination. Although this method is used routinely, its validity and reproducibility do not appear to have been tested.To determine the reproducibility and validity of clinical assessment of nutritional status, we studied the nutritional status of . . .

Herein we describe a methodology which can be used to evaluate the predictive accuracy of nutritional assessment techniques. We use this methodology to compare seven techniques of nutritional assessment in terms of their ability to predict one nutrition associated hospital complication (infection) by dividing a sample of 59 surgical patients into high risk and low risk groups. One technique was subjective global assessment (SGA) of the patient's nutritional status on admission to hospital. Five techniques were single objective measurements (albumin, transferrin, delayed cutaneous hypersensitivity, anthropometry, and creatinine-height index). The 7th technique was the prognostic nutritional index. The best combination of sensitivity (0.82) and specificity (0.72) was found with SGA. The second best combination (0.88 and 0.45) was found by using either the prognostic nutritional index or creatinine-height index. We also found that combining the five objective measurements with SGA into a single index did not increase the discriminatory (or predictive) power over that of SGA alone in a clinically significant way. We conclude that a larger study comparing these approaches should be undertaken to confirm these findings and to develop methods which improve the predictive properties of SGA.

We studied 202 patients admitted to two major teaching hospitals for planned gastrointestinal surgery to assess the ability of several techniques of nutritional assessment to predict major postoperative complications (infection and/or wound problems). Subjective global assessment (SGA) and albumin were both of predictive value, and combinations of these variables were useful in differentiating low-risk from high-risk patients. Transferrin, creatinine-height index, percent ideal weight, percent body fat, and total lymphocyte count were not useful in predicting complications. We conclude that SGA and albumin are useful "nutritional assessment techniques" for patients undergoing major gastrointestinal surgery if the purpose of such an assessment is to predict postoperative "nutrition-associated complications." The second major finding of this study was the unexpectedly low rate of complications (10%) which was found in both hospitals. We suggest that these low complication rates may be more generalizable to patient populations derived from a wide community base, rather than those described in other studies in which veterans or patients of lower socioeconomic status comprised the sample.