Background: There is some controversy about whether all adults receiving healthcare should be routinely screened for nutritional problems.
Methods: (i) A systematic review examined the proposition that malnutrition is under-recognised and under-treated, and that nutritional interventions in malnourished patients, identified through a screening procedure produce clinical benefits (assessed using randomised controlled trials, RCTs). (ii) A systematic review of nutritional screening interventions in populations of malnourished and well-nourished subjects (RCTs and non-RCTs).
Results: (i) The prevalence of malnutrition varies according to the criteria used, but is estimated to affect 10-60% of patients in hospital and nursing homes, 10% or more of older free-living subjects, and less than 5% of younger adults. In the absence of formal screening procedures, more than half the patients at risk of malnutrition in various settings do not appear to be recognised and/or are not referred for treatment. RCTs show that nutritional interventions in malnourished patients produce various clinical benefits. (ii) Interventions with nutritional screening in different care settings also generally suggest clinical benefits, but some are limited by small sample sizes and inadequate methodology. Factors that influence outcomes include validity, reliability and ease of using the screening procedure, the 'care gap' that exists between routine and desirable care and the need for other resources, which may increase or decrease following screening.
Conclusions: The frequent failure to recognise and treat malnutrition, especially where it is common, is unacceptable. In such circumstances, the routine use of a simple screening procedure is recommended. Each health care setting should have a transparent policy about nutritional screening, which may vary according to the 'care gap', available resources, and specific populations of patients, in which the prevalence of malnutrition may vary widely.