title: Derivation and initial application of a standard population for out-of-hospital cardiac arrest (SPOHCA).
abstract: OBJECTIVE
  While adjusting data for age, sex, race and/or socio-economic status is well established in out-of-hospital cardiac arrest (OHCA) research, there are shortcomings to reporting and comparing population-based OHCA outcomes. The purpose of this study was to derive a case-based standard population specific to EMS treated adult OHCA (SPOHCA) in the U.S., and demonstrate its application.
  
  
  METHODS
  The proposed SPOHCA was developed from three sources of multi-site OHCA data: the Cardiac Arrest Registry to Enhance Survival (CARES); the National EMS Information System (NEMSIS); and a published report from the Resuscitation Outcomes Consortium (ROC). OHCA data from a single EMS system were then used to demonstrate the application of SPOHCA. We report raw survival, population-based survival adjusted to the U.S. population, and the new SPOHCA-adjusted survival.
  
  
  RESULTS
  Observed raw survival was 12.3%. Adjustment to the demographic make-up of the adult U.S. population produced an adjusted incidence of 94.2 OHCA per 100,000 p-y, with a survival rate of 9.8 per 100,000 p-y. Using the proposed SPOHCA to adjust survival data produced an adjusted survival rate of 12.4%.
  
  
  CONCLUSIONS
  A case-based standard population provides for more practical interpretation of reported OHCA outcomes. We encourage a more widespread effort involving multiple stakeholders to further explore the effects of adjusting OHCA outcomes using the proposed SPOHCA instead of population-based demographics.
authors.affiliation: Austin-Travis County Office of the Medical Director, 517 S. Pleasant Valley Road, Austin, TX 78741, United States; University of Texas - Austin, Emergency Medicine Residency Program, Clinical Education Center, Suite 2.230, 1400 North IH-35, Austin, TX 78701, United States.
authors.forename: Jose G
authors.initials: JG
authors.lastname: Cabanas
authors.affiliation: University of Texas - Austin, Emergency Medicine Residency Program, Clinical Education Center, Suite 2.230, 1400 North IH-35, Austin, TX 78701, United States; Mount Isa Centre for Rural and Remote Health, James Cook University, Townsville, QLD 4811, Australia. Electronic address: lawrence.brown@my.jcu.edu.au.
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Brown
authors.affiliation: Austin-Travis County Office of the Medical Director, 517 S. Pleasant Valley Road, Austin, TX 78741, United States.
authors.forename: Louis
authors.initials: L
authors.lastname: Gonzales
authors.affiliation: Austin-Travis County Office of the Medical Director, 517 S. Pleasant Valley Road, Austin, TX 78741, United States.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Hinchey
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D016887:Cardiopulmonary Resuscitation; D016208:Databases, Factual; D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality* / Q000628:therapy; D044469:Racial Groups / Q000706:statistics & numerical data; D012042:Registries; D017678:Sex Distribution; D015996:Survival Rate; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: Emergency medical services; Out of hospital cardiac arrest; Standardization of rates