title: Cardiopulmonary arrest and mortality trends, and their association with rapid response system expansion.
abstract: OBJECTIVE
  To understand the changes in the population incidence of inhospital cardiopulmonary arrest (IHCA) and mortality associated with the introduction of rapid response systems (RRSs).
  
  
  METHODS
  Population-based study of 9 221 138 hospital admissions in 82 public acute hospitals in New South Wales, using data linked to a death registry, from 1 Jan 2002 to 31 Dec 2009.
  
  
  METHODS
  Changes in IHCA, IHCA-related mortality, hospital mortality and proportion of IHCA patients surviving to hospital discharge.
  
  
  RESULTS
  RRS uptake increased from 32% in 2002 to 74% in 2009. This increase was associated with a 52% decrease in IHCA rate, a 55% decrease in IHCA-related mortality rate, a 23% decrease in hospital mortality rate and a 15% increase in survival to discharge after an IHCA (all P < 0.01). The adjusted absolute reductions in IHCA-related mortality and hospital mortality were 1.49 (95% CI, 1.30-1.68) and 4.05 (95% CI, 3.17-4.76) patients per 1000 admissions, respectively. The decrease in IHCA incidence rate accounted for 95% of the reduction in IHCA-related mortality. In contrast, the increase in IHCA survival accounted for only 5% of the reduction in IHCA-related mortality.
  
  
  CONCLUSIONS
  During nearly a decade, as RRSs were progressively introduced, there was a coincidental reduction in IHCA, IHCA-related deaths and hospital mortality and an increased survival to hospital discharge after an IHCA. Reduced IHCA incidence, rather than improved postcardiac arrest survival, was the main contributor to the reduction in IHCA mortality.
authors.affiliation: University of New South Wales, Sydney, NSW, Australia. jackchen@unsw.edu.au.
authors.forename: Jack
authors.initials: J
authors.lastname: Chen
authors.affiliation: University of New South Wales, Sydney, NSW, Australia.
authors.forename: Lixin
authors.initials: L
authors.lastname: Ou
authors.affiliation: University of New South Wales, Sydney, NSW, Australia.
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Hillman
authors.affiliation: Intensive Care, Royal Adelaide Hospital, Adelaide, SA, Australia.
authors.forename: Arthas
authors.initials: A
authors.lastname: Flabouris
authors.affiliation: Austin Hospital, Melbourne, VIC, Australia.
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Bellomo
authors.affiliation: University of New South Wales, Sydney, NSW, Australia.
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Hollis
authors.affiliation: University of New South Wales, Sydney, NSW, Australia.
authors.forename: Hassan
authors.initials: H
authors.lastname: Assareh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006323:Heart Arrest / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D017052:Hospital Mortality / Q000639:trends; D057209:Hospital Rapid Response Team / Q000706:statistics & numerical data* / Q000639:trends; D006779:Hospitals, Public / Q000706:statistics & numerical data / Q000639:trends; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009517:New South Wales / Q000453:epidemiology; D010043:Outcome and Process Assessment, Health Care; D012042:Registries