Studying outcomes of intensive care unit survivors: the role of the cohort study.

Abstract

As research focuses on long-term patient outcomes and the "real world" effectiveness of intensive care unit (ICU) therapies, the cohort study is increasingly being used in critical care research. Using examples of prior cohort studies in intensive care, we review the key elements of this research design and evaluate its advantages and limitations for critical care research. Furthermore, through a systematic search of the literature we summarize data from 70 prior published cohort studies of medium- and long-term outcomes in adult critical care medicine. This research demonstrates that the prospective cohort study is a powerful research design that has not been fully leveraged to assess relationships between exposures and long-term outcomes of ICU survivors. We make recommendations for the design of future cohort studies to maximize the impact of this research in improving the long-term outcomes of critically ill patients.