The effectiveness of advanced airway management (AAM) for out-of-hospital cardiac arrest (OHCA) has been reported differently in each region; however, no study has accounted for the regional differences in the association between the timing of AAM implementation and neurological outcomes.

This study aimed to evaluate the association between the timing of patient or prefecture level AAM and a favorableneurological outcome defined by cerebral performance category 1 or 2 (CPC 1–2).

A retrospective cohort study was conducted using data from the All-Japan Utstein Registry between 2013 and 2017. We included patients aged ≥8 years with OHCA for whom AAM (i.e., supraglottic airway or endotracheal intubation) was performed in a prehospital setting (n = 182,913). We divided the patients into shockable (n = 11,740) and non-shockable (n = 171,173) cohorts based on the initial electrocardiogram rhythm. Multilevel logistic regression analysis estimated the association between AAM time (patient contact-to-AAM performance interval) at the patient level (1-min unit increments), prefecture level (> 9.2 min vs. ≤ 9.2 min) and CPC 1–2.

A delay in AAM time was negatively associated with CPC 1–2 (adjusted odds ratio [AOR], 0.92, 0.96; 95% confidence interval [CI], 0.90–0.93, 0.95–0.97, respectively), regardless of initial rhythm. At the prefecture level, a delay in AAM time was negatively associated with CPC 1–2 (AOR, 0.77, 0.68; 95% CI, 0.58–1.04, 0.50–0.94, respectively) only in the non-shockable cohort.

A delay in AAM performance was negatively associated with CPC 1–2 in both shockable and non-shockable cohorts. Moreover, a delay in AAM performance at the prefecture level was negatively associated with CPC 1–2 in the non-shockable cohort.