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Hospital-free days: A pragmatic and patient-centered outcome for trials among critically and seriously ill patients

American Journal of Respiratory and Critical Care Medicine October 15, 2021

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Research Areas


Hospital-free days (HFDs) is increasingly selected as the primary or secondary outcome in clinical trials among critically and seriously ill patients. This outcome measure, alternatively known as days alive and outside the hospital (DAOH), was first used as a primary outcome in the 2005 ESCAPE (Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness) Trial assessing the effectiveness of pulmonary artery catheterization in the management of congestive heart failure. Since then, DAOH or HFDs have been used as a primary outcome in several studies across a broad range of medical and surgical conditions. HFDs offers many advantages to traditional endpoints used in clinical trials but also presents potential challenges. In this perspective, we highlight important considerations relevant to HFDs using real-world examples from recent and upcoming clinical trials. In doing so, we identify opportunities for future scholarship to advance HFDs as a patient-centered clinical outcome measure.


National Heart, Lung, and Blood Institute (NHLBI)
National Insitiute of Nursing Research ( NINR)
National Library of Medicine (NLM)