Determining the level of prealbumin, a hepatic protein, is a sensitive and cost-effective method of assessing the severity of illness resulting from malnutrition in patients who are critically ill or have a chronic disease. Prealbumin levels have been shown to correlate with patient outcomes and are an accurate predictor of patient recovery. In high-risk patients, prealbumin levels determined twice weekly during hospitalization can alert the physician to declining nutritional status, improve patient outcome, and shorten hospitalization in an increasingly cost-conscious economy.