title: The prognostic importance of a small acute decrement in kidney function in hospitalized patients: a systematic review and meta-analysis.
abstract: BACKGROUND
  Recently, acute kidney injury defined by small changes in serum creatinine levels was associated with worse short-term outcomes; however, the precision and variability of this association was not fully explored.
  
  
  METHODS
  Systematic review and meta-analysis.
  
  
  METHODS
  Hospitalized patients.
  
  
  METHODS
  MEDLINE and EMBASE databases were searched for observational cohort studies and randomized controlled trials published from 1990 through February 2007 that provided information for small changes in serum creatinine levels.
  
  
  METHODS
  Small acute changes in serum creatinine levels by absolute and percentage of changes in serum creatinine levels (lower threshold for increase in serum creatinine <0.5 mg/dL or <25%).
  
  
  RESULTS
  Short-term mortality (<or=30 days).
  
  
  RESULTS
  Compared with controls, patients with a 10% to 24% increase in creatinine levels had a relative risk (RR) of death of 1.8 (95% confidence interval [CI], 1.3 to 2.5). By comparison, subjects with a 25% to 49% acute change in creatinine levels had an RR of death of 3.0 (95% CI, 1.6 to 5.8), and those with the largest change (>or=50%) had the greatest RR of death (RR, 6.9; 95% CI, 2.0 to 24.5). Results were similar when absolute changes in creatinine levels were considered and when pooled estimates of adjusted RR were used.
  
  
  CONCLUSIONS
  Individual patient data were unavailable; thus, only group-level data were pooled for meta-analysis. Results showed a significant degree of statistical heterogeneity that was only partially ameliorated by separating studies into subsets based on clinical setting.
  
  
  CONCLUSIONS
  Short-term mortality and acute decreases in renal function are associated through a graded relationship such that even mild changes in serum creatinine levels portend worse outcome in a variety of clinical settings and patient-types.
authors.affiliation: Clinical Epidemiology Research Center, VA Connecticut Healthcare System, West Haven, USA.
authors.forename: Steven G
authors.initials: SG
authors.lastname: Coca
authors.forename: Aldo J
authors.initials: AJ
authors.lastname: Peixoto
authors.forename: Amit X
authors.initials: AX
authors.lastname: Garg
authors.forename: Harlan M
authors.initials: HM
authors.lastname: Krumholz
authors.forename: Chirag R
authors.initials: CR
authors.lastname: Parikh
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood* / Q000453:epidemiology; D015897:Comorbidity; D003404:Creatinine / Q000097:blood*; D006333:Heart Failure / Q000453:epidemiology*; D006760:Hospitalization; D006801:Humans; D007677:Kidney Function Tests; D011379:Prognosis
chemical_list: D003404:Creatinine