title: Incidence and outcomes of acute kidney injury in a referred chronic kidney disease cohort.
abstract: BACKGROUND
  Whilst chronic kidney disease (CKD) has been identified as a risk factor for the development of acute kidney injury (AKI), little has been published about the incidence and outcomes of those acute injuries on chronic stable kidney disease and even less in a referred cohort of CKD patients followed up by nephrologists.
  
  
  METHODS
  We followed up 6862 patients registered as CKD in British Columbia, Canada for a median time of 19.4 months after they achieved an estimated glomerular filtration rate (eGFR) value < or =30 mL/min/1.73 m(2). AKI was defined as a decrease in eGFR of > or =25% compared to a moving baseline eGFR within 25 days.
  
  
  RESULTS
  Of the CKD patients, 44.9% had at least one AKI episode. Crude incidence rate for a first AKI event was 34.8 per 100 person-years. Older age [adjusted relative risks (RR) = 0.93 by 10 years, 95% confidence intervals (CI) = 0.90, 0.95] was associated with a lower risk of AKI. Of the patients, 15.3% died before dialysis and 18.1% initiated dialysis. AKI was associated with both a higher risk of death (adjusted RR = 2.32, 95% CI = 2.04, 2.64) and an increased risk of dialysis (adjusted RR = 2.33, 95% CI = 2.07, 2.61).
  
  
  CONCLUSIONS
  In a referred CKD population, AKI was a frequent event and associated with higher risks of dialysis and mortality. The incidence of AKI appears to be less with older age in this population. Quantification of AKI incidence and its risk factors in different populations is important for clinicians and planners, so that appropriate identification, prevention and treatment strategies can be tested.
authors.affiliation: Service de Néphrologie, Hôpital Maisonneuve-Rosemont, Montréal, Canada. jean-philippe.lafrance@umontreal.ca
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Lafrance
authors.forename: Ognjenka
authors.initials: O
authors.lastname: Djurdjev
authors.forename: Adeera
authors.initials: A
authors.lastname: Levin
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D000368:Aged; D000369:Aged, 80 and over; D001955:British Columbia; D002908:Chronic Disease; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D015994:Incidence; D007674:Kidney Diseases / Q000150:complications*; D007676:Kidney Failure, Chronic / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D003404:Creatinine