Derivation and initial application of a standard population for out-of-hospital cardiac arrest (SPOHCA)

AimWhile 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.MethodsThe 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.ResultsObserved 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%.ConclusionA 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.