Effects of cardiopulmonary resuscitation instructions on the outcomes of out‐of‐hospital cardiac arrest: An analysis of the JAAM‐OHCA registry

AIM: To determine whether dispatcher‐provided cardiopulmonary resuscitation (CPR) instructions improve the outcomes of out‐of‐hospital cardiac arrest (OHCA). METHODS: Cases registered in the Japanese Association for Acute Medicine Out‐of‐Hospital Cardiac Arrest (JAAM‐OHCA) Registry between June 2014 and December 2019 were included. Cases in which the dispatcher provided CPR instructions to the bystander were included in the “Instructions” group”, and cases without CPR instructions were included in the “No Instructions” group. The primary outcome was the proportion of patients with a favorable neurological outcome, defined as a Glasgow–Pittsburgh cerebral performance category scale of 1 to 2 at 1 month after OHCA. RESULTS: Overall, 51,199 patients with OHCA were registered in the JAAM‐OHCA Registry during the study period. Of these, 33,745 were eligible for the study, with 16,509 in the Instructions group and 17,236 in the No Instructions group. The proportion of patients with a favorable neurological outcome at 1 month after OHCA was inferior in the Instructions group than in the No Instructions group (2.3% versus 3.0%, p < 0.001). After adjustment for patient background characteristics, no association was found between CPR instructions provided by a dispatcher and favorable neurological outcomes at 1 month after OHCA (adjusted odds ratio, 1.000; 95% confidence interval, 0.869–1.151, p = 0.996). CONCLUSION: The present study found no clear clinical benefit of dispatcher‐provided CPR instructions on the neurological outcomes of cases with OHCA.