Regional implementation of a prehospital advanced life support program with video-assisted physician direction and outcomes after out-of-hospital cardiac arrest.

BACKGROUND

The smart advanced life support (SALS) program was introduced to provide prehospital advanced life support under real-time video-assisted physician direction for out-of-hospital cardiac arrest (OHCA). This study evaluated the association between regional SALS implementation and OHCA outcomes.

METHODS

This retrospective cohort study used difference-in-differences and event-study analyses with data from the OHCA surveillance system in South Korea and included adult OHCA cases (aged ≥19 years) from 2 years before through 4 years after SALS implementation in August 2015. The exposure was region-level implementation of SALS. Outcomes were the prehospital time interval, prehospital return of spontaneous circulation (ROSC), survival to discharge, and favorable neurological outcome. Pre- to post-implementation changes were compared between regions with and without SALS.

RESULTS

A total of 129,207 cases were included. SALS regions had greater increases in the prehospital time interval (4.12 minutes; 95% confidence interval [CI], 2.91 to 5.33) and prehospital ROSC (1.35 percentage points; 95% CI, 0.56 to 2.15) than regions without SALS. No significant additional improvements were observed in survival to discharge (-0.35 percentage points; 95% CI, -1.31 to 0.62) or favorable neurological outcome (-0.35 percentage points; 95% CI, -1.08 to 0.37). Event-study analyses suggested differential pre-intervention trends for prehospital time, but not for the other outcomes.

CONCLUSION

SALS regions showed greater increases in prehospital time and prehospital ROSC without significant improvements in survival to discharge or favorable neurological outcome, but the finding for prehospital time should be interpreted cautiously because differential pre-intervention trends were observed.