Are prospective cohort studies an appropriate tool to answer clinical nutrition questions?

PURPOSE OF REVIEW

Randomized controlled trials can be difficult to conduct in critically ill patients and may not always be the most appropriate type of study. Cohort studies can provide valuable information in large complete populations of patients without strict exclusion criteria and without the need for informed consent, thus potentially being more representative of and applicable to daily practice.

RECENT FINDINGS

Recent cohort studies have evaluated the various aspects of the epidemiology and practice of nutrition in critically ill patients, including the proportions of patients receiving different types of nutritional support, the potential benefits of supplementary parenteral nutrition, the importance of meeting nutrition targets especially for protein, and the beneficial effects of feeding protocols on outcomes.

SUMMARY

Results from some of these cohort studies have provided an indication of how nutrition guidelines have been applied in clinical practice and which areas need to be improved. Others have generated hypotheses that will be (or are already being) tested in randomized studies.