点击显示 收起
1 From the Geriatric Research, Education and Clinical Center, Durham VA Medical Center, and the Department of Medicine, Duke University Medical Center, Durham, NC.
See corresponding article on page201.
Most clinical nutritionists would agree that in the care of sick or frail elderly patients, nutritional and hydration concerns often rank far too low on the list of evaluation and treatment priorities. In hospitals and nursing homes (1, 2) and in the community, elderly patients may receive a variety of costly and complex medical interventions, eg, extensive drug therapy (3) and mechanical ventilatory support (4), while the routine availability of adequate food and fluids is neglected.
Why isn't nutrition more clearly recognized as a priority for the elderly by health professionals other than nutritionists? The need for nutritional assessment and intervention is particularly crucial in this age group, in whom the incidence of chronic illness is high and a myriad of socioeconomic factors enhance the likelihood of malnutrition (5). In the search for an answer to this question, consider the terminology used to express the findings of nutritional status studies of the elderly (and other age groups, for that matter). The findings of these studies often indicate that the elderly subjects are "at nutritional risk" or "at risk of malnutrition." As nutritionists, we all have an idea of what being at nutritional risk means. But, as evidenced in the literature, although we agree that this is an important issue, we do not always agree about its exact interpretation (6) or implications. For some, being at risk of malnutrition is different from actually being malnourished: being malnourished certainly sounds worse than being at risk of it. Others think that these 2 terms are one and the same. It is not too surprising, then, that our counterparts in the clinic sometimes pay too little attention to nutrition. When compared with the many serious maladies already established and diagnosed in elderly patients, being at risk of malnutrition sounds less than urgent.
The terminology of nutritional risk can also cause difficulties in certain research situations, especially when nutritionists collaborate with clinical investigators from other disciplines. That a particular demographic or physiologic factor might increase or decrease the risk of being at nutritional risk can be a difficult concept to convey, and the selection of statistical methods can be hampered by the seemingly circular logic.
In addition, there is sometimes a lack of consistency in the interpretation of results from different tools used for nutritional screening and assessment in the published literature. For example, although some groups have used the DETERMINE checklist from the Nutrition Screening Initiative to assess nutritional risk (7), it is generally not considered to be a clinical diagnostic tool (8). The checklist is intended mainly to provide education and to increase awareness of nutritional problems in the elderly and thus may not be a particularly good predictor of health outcomes related to nutritional status (6). In fact, several different instruments have been developed for the assessment of nutritional risk [eg, the Mini Nutritional Assessment (9), and the Nutritional Risk Assessment Scale (10)], and all are used more or less interchangeably in the literature to detect risk, although they obviously differ in the exact data collected.
In this issue of the Journal, Jensen et al (11) report the results of a study of nutritional risk in the elderly, noting the importance of using nutrition assessment instruments according to their intended purpose and the need for validation testing of these screening tools. They comment that screening tools "are being used in capacities that far exceed those for which they were originally intended" and recommend that the ability of these tools to predict health and nutrition outcomes be more thoroughly tested. Their study was designed to determine whether elderly subjects found to be at nutritional risk were likely to have poor health outcomes within the subsequent year. They compared the ability of the Level II Nutrition Screen and that of the Probability of Repeated Admission (Pra) questionnaire to predict a recognized marker of poor health outcomes—repeated hospital admissions—in 386 enrollees in a Medicare managed-risk health plan. The Level II Nutrition Screen, from the Nutrition Screening Initiative, was developed to compliment the DETERMINE checklist by providing a more comprehensive nutritional assessment for use in medical settings. The Pra was developed especially to assess the likelihood of hospitalization in older persons and was previously tested for reliability and validity.
The results of the study by Jensen et al show that the Level II Nutrition Screen predicted future hospitalization with an effectiveness comparable with that of the Pra. Moreover, subjects with a high Pra score were more likely to have lost weight and to report consuming special diets. The authors concluded that regardless of the screening approach selected, answers to questions about eating problems, weight loss, and special diets help to predict future hospital admissions in the elderly and should be included in health screenings. In addition, these results underscore the clinical importance of being at nutritional risk and thus help to establish a clearer meaning of the term. The findings provide supporting evidence that nutritional risk should also be considered to be a serious health risk. Certainly, more work of this type, in different and larger populations, is needed to help define the implications of a high nutritional risk and to ensure that the term is recognized as a valid predictor of health outcomes.
We should not necessarily discourage the application of any particular screening tool or abandon the use of the term nutritional risk. The term is embedded in the nutrition and aging literature and is unlikely to be given up. We need to establish a clear and widely held understanding of the descriptive terms commonly used to indicate nutritional status and then to use these terms as specifically as possible. Moreover, studies like the one by Jensen et al can help to explain and confirm the extent of health endangerment that the condition of nutritional risk may contribute and thus, it is hoped, increase recognition of this problem in the elderly.
REFERENCES