Skip to main content


Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Long-term survival for ICU patients with acute kidney injury

  • 770 Accesses


A recently published study [1] validated the criteria used in the Acute Kidney Injury Network (AKIN) definitions [2] of the three stages of acute kidney injury (AKI) using in-hospital mortality. In the present study, we validate the clinical applicability of the AKIN classifications through long-term survival analysis of AKI patients.


From over 17,000 adult ICU patients in the MIMIC II database [3, 4] (V2.5), we excluded patients having end-stage renal disease and those with insufficient data and determined AKI stages for each patient. Multivariate Cox regression was used to determine hazard ratios (HRs) for 2-year survival, controlling for: age, sex, nonrenal Sequential Organ Failure Assessment (SOFA) score and selected co-morbidities.


Among the final cohort of 14,525 patients, 43% had no AKI and 39%, 14% and 4% developed AKI 1, 2 and 3 respectively. The results of the regression analysis show that AKI 1 (HR 1.12, P < 0.05), AKI 2 (HR 1.10, P = 0.05) and AKI 3 (HR 1.64, P < 0.001) were significantly associated with increased 2-year mortality. In addition, age (HR 1.04, P < 0.001), gender (M) (HR 0.93, P < 0.05), nonrenal SOFA score (HR 1.05, P < 0.001) and all co-morbidities were significant predictors. Adjusted and unadjusted Kaplan-Meier curves for patients with AKI 3 are remarkably different from each other, suggesting that in these most severely ill patients AKI is only one aspect of their illness.


AKI stages 1, 2 and 3 are significant indicators of 2-year mortality. The difference between AKI 1 and 2 is smaller than that between AKI 2 and 3 and it may be prudent to re-examine the criteria used to define AKI to provide better separation among the three classes.


  1. 1.

    Mandelbaum T, et al.: Crit Care Med. 2011, 39: 2659-2664.

  2. 2.

    Mehta RL, et al.: Crit Care. 2007, 11: R31. 10.1186/cc5713

  3. 3.

    Saeed M, et al.: Crit Care Med. 2011, 39: 952-960. 10.1097/CCM.0b013e31820a92c6

  4. 4.

    MIMIC II databases[]

Download references

Author information

Correspondence to D Scott.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Scott, D., Cismondi, F., Lee, J. et al. Long-term survival for ICU patients with acute kidney injury. Crit Care 16, P376 (2012).

Download citation


  • Acute Kidney Injury
  • Sequential Organ Failure Assessment
  • Sequential Organ Failure Assessment Score
  • Clinical Applicability
  • Acute Kidney Injury Network