title: Acute kidney injury and mortality in hospitalized patients.
abstract: BACKGROUND
  The objective of this study was to determine the incidence of acute kidney injury (AKI) and its relation with mortality among hospitalized patients.
  
  
  METHODS
  Analysis of hospital discharge and laboratory data from an urban academic medical center over a 1-year period. We included hospitalized adult patients receiving two or more serum creatinine (sCr) measurements. We excluded prisoners, psychiatry, labor and delivery, and transferred patients, 'bedded outpatients' as well as individuals with a history of kidney transplant or chronic dialysis. We defined AKI as (a) an increase in sCr of ≥0.3 mg/dl; (b) an increase in sCr to ≥150% of baseline, or (c) the initiation of dialysis in a patient with no known history of prior dialysis. We identified factors associated with AKI as well as the relationships between AKI and in-hospital mortality.
  
  
  RESULTS
  Among the 19,249 hospitalizations included in the analysis, the incidence of AKI was 22.7%. Older persons, Blacks, and patients with reduced baseline kidney function were more likely to develop AKI (all p < 0.001). Among AKI cases, the most common primary admitting diagnosis groups were circulatory diseases (25.4%) and infection (16.4%). After adjustment for age, sex, race, admitting sCr concentration, and the severity of illness index, AKI was independently associated with in-hospital mortality (adjusted odds ratio 4.43, 95% confidence interval 3.68-5.35).
  
  
  CONCLUSIONS
  AKI occurred in over 1 of 5 hospitalizations and was associated with a more than fourfold increased likelihood of death. These observations highlight the importance of AKI recognition as well as the association of AKI with mortality in hospitalized patients.
authors.affiliation: Department of Emergency Medicine, University of Alabama at Birmingham, Birmingham, AL 35249, USA. hwang@uabmc.edu
authors.forename: Henry E
authors.initials: HE
authors.lastname: Wang
authors.forename: Paul
authors.initials: P
authors.lastname: Muntner
authors.forename: Glenn M
authors.initials: GM
authors.lastname: Chertow
authors.forename: David G
authors.initials: DG
authors.lastname: Warnock
mesh_terms: D000046:Academic Medical Centers / Q000706:statistics & numerical data; D058186:Acute Kidney Injury / Q000097:blood / Q000453:epidemiology* / Q000401:mortality; D000328:Adult; D000367:Age Factors; D000368:Aged; D000407:Alabama / Q000453:epidemiology; D016001:Confidence Intervals; D003404:Creatinine / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D017052:Hospital Mortality; D006801:Humans; D015994:Incidence; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D012720:Severity of Illness Index; D014505:Urban Population / Q000706:statistics & numerical data
chemical_list: D003404:Creatinine