or many years, we believed that a good outcome for critically ill patients was for them to leave the intensive care unit (ICU) alive. Sadly, we now know from substantial research, including in-depth follow-up of individual patients, that this is not the case.

Many cohort studies of critically ill patients that prospectively followed people after hospital discharge raised concerns regarding long-term outcomes (1–4). Despite the importance of this work, such prospective cohort studies are limited in the type and amount of information they can provide because of small sample size or number of outcome events, uncertain generalizability, and a lack of information on prehospital trajectories. Perhaps most important, many of these exploratory studies lacked comparison with appropriate controls. Therefore, the burden of morbidity and mortality after critical illness was quantified, but with uncertainty regarding the level of attribution to the critical illness and its associated treatments and the contribution of either underlying comorbidity or hospitalization of any kind. In effect, these studies identified that “we have a problem,” but their limitations did not allow us to more fully understand the severity, duration, causation, and trajectory of these problems from the perspectives of our patients and our health systems.