Malnutrition and bad outcomes.

In this issue of the Journal, Sullivan et al. provide important new evidence that poor nutritional status is a worrisome sign in hospitalized patients.1 After adjustment for other markers of illness severity, patients who were malnourished on admission were at markedly higher risk of life-threatening complications during hospitalization such as arrhythmia, sepsis, or hemorrhage. Other studies have shown that poor nutritional status predicts adverse outcomes following hospital discharge.2–4 For example, we found that patients malnourished on hospital admission were more likely to experience dependence in activities of daily living, require nursing home care, and die within 1 year of hospital discharge.4 Clearly, malnutrition is a marker for bad outcomes in hospitalized elders. But, does malnutrition actually cause bad outcomes? And more importantly, would treating malnutrition improve outcomes? The answer to both of these questions is uncertain. Demonstrating that malnourished patients do poorly does not prove that malnutrition causes poor outcomes. Since malnutrition has complex relationships with illness severity, studies of the relationship between malnutrition and outcomes should rigorously control for illness severity. An important strength of the study by Sullivan et al. was the finding that malnutrition predicted complications after adjusting for multiple measures of illness severity such as APACHE and Charlson scores and functional status. However, since none of these measures completely capture illness severity, it is also possible that nutritional status is simply capturing unmeasured illness severity. Demonstrating that treating malnutrition improves outcomes would be the most convincing evidence that malnutrition actually causes poor outcomes. However, evidence that aggressive treatment of malnutrition improves outcomes is surprisingly sparse. Such evidence is limited to select subgroups, such as patients undergoing major abdominal or thoracic surgery.5 Several small studies also suggest that nutritional interventions may improve outcomes following hip fracture.6 However, there is virtually no evidence that aggressive nutritional interventions improve outcomes in general groups of hospitalized patients. Because interventions such as tube feedings have significant risks and can result in patient discomfort, their routine use in hospitalized patients should not be recommended without evidence of their effectiveness. In particular, the burdens of invasive nutritional interventions may outweigh the benefit in patients in whom malnutrition represents the end stage of a disease process, such as those with advanced dementia.7 Even though evidence that nutritional support improves outcomes is lacking, nutritional assessment remains useful as a prognostic marker and is often important to patients and families. However, physicians often fail to recognize malnutrition in hospitalized patients. For example, Mowe and Bohmer found that less than half of severely malnourished patients had any medical record documentation of their nutritional status.8 Many physicians consider measurement of serum proteins such as albumin to be an adequate assessment of nutritional status. However, in hospitalized patients, albumin is influenced by too many other factors to be a sufficient measure of nutritional status.9 For example, we recently demonstrated that serum albumin correlated very poorly with assessments of nutritional status based on a patient's history and physical exam.10 Notably, the study by Sullivan et al. found that albumin did not predict complications after adjusting for other measures of illness severity. The subjective global assessment is one method physicians can use to systematically document and recognize nutritional problems in their hospitalized patients.11 The subjective global assessment provides a systematic method of obtaining essential information about nutritional status, such as history of weight loss, subcutaneous tissue loss, and muscle wasting, from the history and physical exam. It is easily learned, adds little additional effort to a routine admission history and physical, and is a powerful predictor of adverse outcomes.4,11 Clinicians who wish to learn how to do the subjective global assessment will find the description by Detsky et al. to be an excellent user-friendly guide.11 In addition to its importance as a prognostic marker, another reason to recognize nutritional status in hospitalized elders is to avoid doing additional harm. For example, Sullivan et al. have previously demonstrated that many patients have a markedly inadequate nutritional intake during hospitalization, partly because of orders against oral intake.12 Similarly, Incalzi et al. demonstrated that significant deterioration in nutritional status occurred in 27% of hospitalized patients.13 Although some nutritional depletion during hospitalization may be the result of medical illness, some may also be the result of hospital processes. Clinicians should consider several modifications of traditional processes. First, orders against oral intake should be written with great caution and for as short a time period as possible. Second, dietary restrictions should also be used with caution. In the study by Incalzi et al., there was some evidence linking patients' dissatisfaction with the food served to inadequate intake.13 There is little point to the common practice of carefully titrating a patient's volume and metabolic status with unpalatable dietary restrictions that the patient will not adhere to as an outpatient. Patients should have the right to override their doctors' dietary orders. Third, patients should have free access to food. Food should be readily available on the hospital ward, and families should be encouraged to bring food from home and assist with feedings. Finally, feeding difficulty caused by factors such as lack of dentures or functional dependence needs to be addressed aggressively. Kayser-Jones et al. have demonstrated that in nursing home patients, inadequate oral intake is frequently the result of inadequate assistance with feedings.14 For example, cognitively and functionally impaired patients were often provided inadequate assistance with feeding and drinking, patients were often poorly positioned at mealtimes, and patients often had no access to fluids and food between mealtimes. Anecdotal observations suggest that these problems are also prominent during hospitalizations. Given its high prevalence and association with adverse outcomes, it is important that well conducted trials evaluate the effectiveness of more aggressive nutritional intervention in hospitalized elders. As discussed by Sullivan et al., such studies will need to fully account for the complex relationships between aging, illness severity, and malnutrition in hospitalized elders. Because repletion of protein stores occurs slowly, short-term trials are unlikely to be effective. Also, because malnutrition is generally linked to other problems, such as depression, poor functional status, and lack of social support, nutritional interventions should be part of multicomponent interventions. Pending information from such trials, clinicians should still aim to better recognize malnutrition. Doing so will identify vulnerable patients at risk of poor outcomes and may prevent actions that may worsen nutritional status during hospitalization.