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  • Open Access

Long-term survival for ICU patients with acute kidney injury

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  • 2,
  • 1,
  • 3,
  • 1,
  • 1 and
  • 2
Critical Care201216 (Suppl 1) :P376

  • Published:


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


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.

Authors’ Affiliations

MIT, Cambridge, MA, USA
Beth Israel Deaconess Medical Center, Boston, MA, USA
Sheba Medical Center, Tel Hashomer, Israel


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  3. Saeed M, et al.: Crit Care Med. 2011, 39: 952-960. 10.1097/CCM.0b013e31820a92c6PubMed CentralView ArticlePubMedGoogle Scholar
  4. MIMIC II databases[]


© Scott et al.; licensee BioMed Central Ltd. 2012

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.