title: A framework and key research questions in AKI diagnosis and staging in different environments.
abstract: OBJECTIVE
  Acute Kidney Injury (AKI) is common worldwide, and associated with significant morbidity, mortality, and resource utilization. The RIFLE system of staging AKI correlates with survival in AKI in several settings. A similar AKI definition and staging system that also incorporates lesser degrees of serum creatinine elevation was proposed at the inaugural Acute Kidney Injury Network (AKIN) meeting in 2005. At the Second AKIN meeting in Vancouver, Canada in September 2006, our group developed a research agenda that would test the utility of these diagnostic and staging criteria to predict patient outcomes in a variety of clinical settings and patient groups.
  
  
  METHODS
  Three-day, international, consensus conference. A multidisciplinary stakeholder committee was divided into work groups. Recommendations for clinical practice and for future research were developed by the committee as an iterative process. This procedure consisted of a literature review phase and focus group interactions with presentations to the entire committee.
  
  
  RESULTS
  We first proposed a conceptual framework of disease that describes a series of AKI stages, antecedents and outcomes, and allows a description of research recommendations based on transition between AKI stages. We further proposed methods for testing of the definition and development of research questions to establish the utility of new biomarkers for the diagnosis and staging of AKI and associated illnesses.
  
  
  CONCLUSIONS
  Retrospective studies should be conducted to initiate the process of validating the AKIN definition of AKI, followed by comprehensive prospective studies that incorporate sampling for emerging AKI biomarkers.
authors.affiliation: Department of Medicine, Section of Nephrology, MC 5100, Room S-511, University of Chicago Hospitals, 5841 South Maryland Avenue, Chicago, IL 60637, USA. pmurray@medicine.bsd.uchicago.edu
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Murray
authors.forename: Prasad
authors.initials: P
authors.lastname: Devarajan
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Levey
authors.forename: Kai U
authors.initials: KU
authors.lastname: Eckardt
authors.forename: Joseph V
authors.initials: JV
authors.lastname: Bonventre
authors.forename: Raul
authors.initials: R
authors.lastname: Lombardi
authors.forename: Stefan
authors.initials: S
authors.lastname: Herget-Rosenthal
authors.forename: Adeera
authors.initials: A
authors.lastname: Levin
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism*; D035843:Biomedical Research / Q000458:organization & administration*; D003697:Delphi Technique; D017144:Focus Groups; D006801:Humans; D008954:Models, Biological; D016730:Program Development; D015397:Program Evaluation; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D009626:Terminology as Topic
chemical_list: D015415:Biomarkers