Hospital-level variation in the development of persistent critical illness



Patients with persistent critical illness may account for up to half of all intensive care unit (ICU) bed-days. It is unknown if there is hospital variation in the development of persistent critical illness and if hospital performance affects the incidence of persistent critical illness.


This is a retrospective analysis of Veterans admitted to the Veterans Administration (VA) ICUs from 2015 to 2017. Hospital performance was defined by the risk- and reliability-adjusted 30-day mortality. Persistent critical illness was defined as an ICU length of stay of at least 11 days. We used 2-level multilevel logistic regression models to assess variation in risk- and reliability-adjusted probabilities in the development of persistent critical illness.


In the analysis of 100 hospitals which encompassed 153,512 hospitalizations, 4.9% (N = 7640/153,512) developed persistent critical illness. There was variation in the development of persistent critical illness despite controlling for patient characteristics (intraclass correlation: 0.067, 95% CI 0.049–0.091). Hospitals with higher risk- and reliability-adjusted 30-day mortality had higher probabilities of developing persistent critical illness (predicted probability: 0.057, 95% CI 0.051–0.063, p < 0.01) compared to those with lower risk- and reliability-adjusted 30-day mortality (predicted probability: 0.046, 95% CI 0.041–0.051, p < 0.01). The median odds ratio was 1.4 (95% CI 1.33–1.49) implying that, for two patients with the same physiology on admission at two different VA hospitals, the patient admitted to the hospital with higher adjusted mortality would have 40% greater odds of developing persistent critical illness.


Hospitals with higher risk- and reliability-adjusted 30-day mortality have a higher probability of developing persistent critical illness. Understanding the drivers of this variation may identify modifiable factors contributing to the development of persistent critical illness.

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This work was supported by Grants NHLBI T32 HL7749-25 (EMV), K12 HL138039 (EMV, TJI). Dr. Bagshaw is supported by a Canada Research Chair in Critical Care Nephrology.

Author information




EMV designed the study, performed the statistical analyses, interpreted the results, compiled the manuscript, and is accountable for all aspects of the work. SMB interpreted the results and provided critical revisions for the manuscript. RB interpreted the results and provided critical revisions for the manuscript. JM interpreted the results and provided critical revisions for the manuscript. XQW performed statistical analyses and provided critical revisions for the manuscript. SS refined the analysis, assisted in interpreting the findings, and provided critical revisions for the manuscript. TJI consulted on the design of the study, refined the analyses, assisted in interpreting the findings, and provided critical revisions of the manuscript.

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Correspondence to Elizabeth M. Viglianti.

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Viglianti, E.M., Bagshaw, S.M., Bellomo, R. et al. Hospital-level variation in the development of persistent critical illness. Intensive Care Med (2020).

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  • Outcomes
  • Prolonged ICU stay
  • Persistent critical illness
  • Hospital variation
  • Multilevel analysis