Secondary Public Safety Answering Points Delay the Response to out of Hospital Cardiac Arrest.

Background: National guidelines recommend that high-performing systems process 9-1-1 calls within 60 s and deliver the first telecommunicator cardiopulmonary resuscitation compression within 90 s. The inability of systems employing secondary public safety answering points (PSAPs) to capture the call arrival timestamp at the primary PSAP is a challenge in out-of-hospital cardiac arrest response time research. Objective: We sought to measure the interval from call receipt at primary PSAPs to call answer at secondary PSAPs in metropolitan areas. Methods: This was a retrospective observational study evaluating 9-1-1 call transfers between PSAPs serving large urban populations. Call transfer records were extracted from the 9-1-1 telephony systems at the primary and secondary PSAPs covering seven metropolitan EMS systems. For each transferred call, we obtained the call arrival timestamp at both the primary and secondary PSAPs. The primary outcome was the interval between these two times. Results were compared to a national standard of 90% of calls forwarded within 30 s of receipt. Results: Data collected at seven metropolitan EMS agencies from January 1, 2021, through June 30, 2021, yielded 299,679 records for evaluation. The median interval required to transfer a 9-1-1 caller from primary to secondary PSAPs was 41 s (IQR 31, 59), and 86 s at the 90th percentile. The 90th percentile performance level at individual agencies ranged from 63 s to 117 s. Conclusions: The primary to secondary PSAP transfer interval lengths observed in this study preclude these EMS agencies from meeting out-of-hospital cardiac arrest performance recommendations at the 90% percentile performance level.