BackgroundFor an effective dispatcher-assisted cardiopulmonary resuscitation (CPR) program, recognition of out-of-hospital cardiac arrest (OHCA) by a dispatcher is the first step in initiating bystander CPR. This study evaluated whether CPR awareness in the community is associated with recognition of arrest, dispatcher-provided CPR instructions, and bystander CPR. MethodsAll emergency medical services (EMS)-treated adult OHCAs with cardiac etiology were enrolled between 2013 and 2015, excluding cases witnessed by EMS providers. Exposure was CPR awareness in the community where the OHCA occurred. Endpoints were recognition of arrest, dispatcher-provided CPR instructions, and bystander CPR. Multilevel logistic regression analysis was performed to calculate adjusted odds ratios (AORs) per 10% increment in community CPR awareness adjusting for potential confounders. ResultsOf 44,185 eligible OHCAs, 20,255 (45.8%) cases were recognized by a dispatcher, 17,858 (40.4%) received dispatcher-provided CPR instructions, and 22,255 (50.4%) received bystander CPR (39.8% with dispatcher assistance and 10.6% without dispatcher assistance). Compared with OHCAs that occurred in the communities with low awareness, dispatchers were more likely to provide CPR instructions to the caller, and bystanders were more likely to perform CPR for OHCAs that occurred in the communities with high CPR awareness. AORs (95% CIs) per 10% increment in public awareness of CPR in the community were 1.05 (1.01–1.10) for recognition of arrest, 1.11 (1.06–1.16) for dispatcher-provided CPR instructions, and 1.07 (1.03–1.11) for bystander CPR. ConclusionsPublic CPR awareness of the communities where OHCAs occurred was associated with recognition of arrest during an emergency call, dispatcher-provided CPR instructions, and bystander CPR.