title: KDIGO-based acute kidney injury criteria operate differently in hospitals and the community-findings from a large population cohort.
abstract: Early recognition of acute kidney injury (AKI) is important. It frequently develops first in the community. KDIGO-based AKI e-alert criteria may help clinicians recognize AKI in hospitals, but their suitability for application in the community is unknown.
  
  
  
  In a large renal cohort (n = 50 835) in one UK health authority, we applied the NHS England AKI 'e-alert' criteria to identify and follow three AKI groups: hospital-acquired AKI (HA-AKI), community-acquired AKI admitted to hospital within 7 days (CAA-AKI) and community-acquired AKI not admitted within 7 days (CANA-AKI). We assessed how AKI criteria operated in each group, based on prior blood tests (number and time lag). We compared 30-day, 1- and 5-year mortality, 90-day renal recovery and chronic renal replacement therapy (RRT).
  
  
  
  In total, 4550 patients met AKI e-alert criteria, 61.1% (2779/4550) with HA-AKI, 22.9% (1042/4550) with CAA-AKI and 16.0% (729/4550) with CANA-AKI. The median number of days since last blood test differed between groups (1, 52 and 69 days, respectively). Thirty-day mortality was similar for HA-AKI and CAA-AKI, but significantly lower for CANA-AKI (24.2, 20.2 and 2.6%, respectively). Five-year mortality was high in all groups, but followed a similar pattern (67.1, 64.7 and 46.2%). Differences in 5-year mortality among those not admitted could be explained by adjusting for comorbidities and restricting to 30-day survivors (hazard ratio 0.91, 95% confidence interval 0.80-1.04, versus hospital AKI). Those with CANA-AKI (versus CAA-AKI) had greater non-recovery at 90 days (11.8 versus 3.5%, P < 0.001) and chronic RRT at 5 years (3.7 versus 1.2%, P < 0.001).
  
  
  
  KDIGO-based AKI criteria operate differently in hospitals and in the community. Some patients may not require immediate admission but are at substantial risk of a poor long-term outcome.
authors.affiliation: Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Sawhney
authors.affiliation: Renal Unit, NHS Grampian, Aberdeen, UK.
authors.forename: Nick
authors.initials: N
authors.lastname: Fluck
authors.affiliation: Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Simon D
authors.initials: SD
authors.lastname: Fraser
authors.affiliation: Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Angharad
authors.initials: A
authors.lastname: Marks
authors.affiliation: Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Gordon J
authors.initials: GJ
authors.lastname: Prescott
authors.affiliation: Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Roderick
authors.affiliation: Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Corri
authors.initials: C
authors.lastname: Black
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000453:epidemiology*; D000368:Aged; D000369:Aged, 80 and over; D000066491:Clinical Decision-Making / Q000379:methods*; D015331:Cohort Studies; D055812:Community-Based Participatory Research; D003628:Database Management Systems / Q000592:standards*; D016208:Databases, Factual; D004739:England / Q000453:epidemiology; D005260:Female; D006761:Hospitals; D006801:Humans; D008297:Male; D008875:Middle Aged
keywords: acute kidney injury; delivery of health care; epidemiology; primary health care; survival analysis