Zhang Z, et al. - Using the eICU Collaborative Research Database, researchers performed this retrospective cohort analysis of sepsis patients, to define when these patients would be stabilized and transitioned to persistent critical illness, and if there is a difference in such transition time between latent classes of patients. Persistent critical illness was described at the time when acute physiological features, vs antecedent features, were no longer more predictive of in-hospital mortality (ie, vital status at hospital discharge). Findings revealed the occurrence of persistent critical illness in a minority of sepsis cases but vast medical resources were consumed by it. Experts discovered 5 latent classes. In classes 1 and 2, the Sequential Organ Failure Assessment score increased over time and the transition to persistent critical illness happened at 16 and 27 days, respectively. A constant decline in Sequential Organ Failure Assessment scores, as well as the occurrence of transition to persistent critical illness between 6 and 8 days, was noted in the rest of the classes. The high urea-to-creatinine ratio was identified as a good biochemical signature of persistent critical illness. Across latent classes, a substantial difference in the transition time was evident, suggesting that the allocation of medical resources should be tailored to distinct classes of patients.