Improved neurologically favorable survival after OHCA is associated with increased pre-hospital advanced airway management at the prefecture level in Japan

Out-of-hospital cardiac arrest (OHCA) has high incidence and mortality. The survival benefit of pre-hospital advanced airway management (AAM) for OHCA remains controversial. In Japan, pre-hospital AAM are performed for OHCA by emergency medical services (EMS), however the relationship between resuscitation outcomes and AAM at the prefecture level has not been evaluated. The purpose of this study was to describe the association between AAM and neurologically favorable survival (cerebral performance category (CPC) ≦2) at prefecture level. This was a retrospective, population-based study of adult OHCA patients (≧ 18) from January 1, 2014 to December 31, 2017 in Japan. We excluded patients with EMS witnessed arrests. We also only included patients that had care provided by an ELST with the ability to provided AAM and excluded cases that involved prehospital care delivered by a physician. We categorized OHCA into four quartiles (four group: G1-G4) based on frequency of pre-hospital AAM approach rate by prefecture, which is the smallest geographical classification unit, and evaluated the relationship between frequency of pre-hospital AAM approach rates and CPC ≦ 2 for each quartile. Multivariable logistic regression was used to assess effectiveness of AAM on neurologically favorable survival. Among 493,577 OHCA cases, 403,707 matched our inclusion criteria. The number of CPC ≦ 2 survivors increased from G1 to G4 (p for trend < 0.001). In the adjusted multivariable regression, higher frequency of pre-hospital AAM approach was associated with CPC ≦ 2 (p < 0.001). High prefecture frequency of pre-hospital AAM approach was associated with neurologically favorable survival (CPC ≦ 2) in OHCA.