John: Hello, I'm John Hilton, editor of the Cochrane Editorial unit. Studies have shown that up to half of adult patients in hospital suffer from malnutrition, and a new Cochrane Review from May 2017 examines the evidence on the effects of nutrition support. We asked Joshua Feinberg, from the Copenhagen Trial Unit in the Rigshospitalet in Denmark, who led the team of 20 authors from Denmark and China to tell us what they found.

Joshua: Malnourished adults have poorer clinical outcomes in hospital than those who are not malnourished, but it’s not clear if the malnutrition causes this or whether both the malnourishment and the poorer outcomes are merely associated with the patient’s underlying disease.
Therefore, we investigated whether nutrition support could reduce the risk of death or serious adverse events for hospitalised adults considered at nutritional risk. We also wanted to look at the impact on their health-related quality of life, but there was insufficient evidence to do so.
Nutrition support usually encompasses general nutrition support, fortified foods, oral supplements, tube-feeding (which is also called enteral nutrition), and intravenous, or parenteral, nutrition, and sought evidence for all these.
After an extensive, global search we included more than 240 randomised trials with nearly 29,000 hospitalised adults, most of whom received a standard hospital diet. The trials ranged in size from 8 to 4640 participants, and the patients had a variety of diseases from 20 different medical specialties.
Overall, we found no evidence of an effect of nutrition support on the risk of either death or serious adverse events, whether patients were followed in the short-or long-term. There was also no evidence of variation across subgroup analyses, when we looked at the data based on amounts of calories or the reasons for nutrition support. In our analysis, patients given nutrition support did put on weight, with an average increase of approximately 1300 grams, but the clinical relevance of this is questionable, because of the limited evidence that weight is a relevant outcome for the patient.
The one area that looked promising was tube-feeding, or enteral nutrition, and the benefits seemed to be in serious adverse events only. However, this result needs to be confirmed in further randomised trials if it is to be convincing enough to influence decisions about care for malnourished, hospitalised adults.

John: For those who would like to look at these issues in more detail, including information on the enormous number of randomised trials in the review, you can find the full version at Cochrane Library dot com. If you go to the website and type in 'nutrition support in hospital’' it will appear at the top of the list of Cochrane Reviews.