title: Variability in case-mix adjusted in-hospital cardiac arrest rates.
abstract: BACKGROUND
  It is unknown how in-hospital cardiac arrest (IHCA) rates vary across hospitals and predictors of variability.
  
  
  OBJECTIVE
  Measure variability in IHCA across hospitals and determine if hospital-level factors predict differences in case-mix adjusted event rates.
  
  
  METHODS
  Get with the Guidelines Resuscitation (GWTG-R) (n=433 hospitals) was used to identify IHCA events between 2003 and 2007. The American Hospital Association survey, Medicare, and US Census were used to obtain detailed information about GWTG-R hospitals.
  
  
  METHODS
  Adult patients with IHCA.
  
  
  METHODS
  Case-mix-adjusted predicted IHCA rates were calculated for each hospital and variability across hospitals was compared. A regression model was used to predict case-mix adjusted event rates using hospital measures of volume, nurse-to-bed ratio, percent intensive care unit beds, palliative care services, urban designation, volume of black patients, income, trauma designation, academic designation, cardiac surgery capability, and a patient risk score.
  
  
  RESULTS
  We evaluated 103,117 adult IHCAs at 433 US hospitals. The case-mix adjusted IHCA event rate was highly variable across hospitals, median 1/1000 bed days (interquartile range: 0.7 to 1.3 events/1000 bed days). In a multivariable regression model, case-mix adjusted IHCA event rates were highest in urban hospitals [rate ratio (RR), 1.1; 95% confidence interval (CI), 1.0-1.3; P=0.03] and hospitals with higher proportions of black patients (RR, 1.2; 95% CI, 1.0-1.3; P=0.01) and lower in larger hospitals (RR, 0.54; 95% CI, 0.45-0.66; P<0.0001).
  
  
  CONCLUSIONS
  Case-mix adjusted IHCA event rates varied considerably across hospitals. Several hospital factors associated with higher IHCA event rates were consistent with factors often linked with lower hospital quality of care.
authors.affiliation: Department of Emergency Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania, USA. raina.merchant@uphs.upenn.edu
authors.forename: Raina M
authors.initials: RM
authors.lastname: Merchant
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.forename: Lance B
authors.initials: LB
authors.lastname: Becker
authors.forename: Robert A
authors.initials: RA
authors.lastname: Berg
authors.forename: Vinay
authors.initials: V
authors.lastname: Nadkarni
authors.forename: Graham
authors.initials: G
authors.lastname: Nichol
authors.forename: Brendan G
authors.initials: BG
authors.lastname: Carr
authors.forename: Nandita
authors.initials: N
authors.lastname: Mitra
authors.forename: Steven M
authors.initials: SM
authors.lastname: Bradley
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Abella
authors.forename: Peter W
authors.initials: PW
authors.lastname: Groeneveld
mesh_terms: D000328:Adult; D006276:Health Facility Size / Q000706:statistics & numerical data; D006323:Heart Arrest / Q000453:epidemiology*; D006761:Hospitals / Q000592:standards / Q000706:statistics & numerical data*; D006801:Humans; D019984:Quality Indicators, Health Care / Q000706:statistics & numerical data; D012042:Registries; D020379:Risk Adjustment / Q000706:statistics & numerical data*; D014481:United States / Q000453:epidemiology