Centralization of post-resuscitation care after out-of-hospital cardiac arrest at cardiac arrest centres: a Danish nationwide follow-up study

BACKGROUND: Recent guidelines recommend centralization of post-resuscitation care in out-of-hospital cardiac arrest (OHCA)-patients. Centralization has been gradually implemented in Denmark since 2009; however, no evaluation of centralization has yet been made. This study assesses the 30-day mortality before and after centralization, and the impact of centralization on survival in Denmark. METHODS: This nationwide study included consecutive adult OHCA patients with presumed cardiac cause admitted to a hospital. Centralization was introduced in 2009, 2011, and 2012 in four out of five regions. Temporal trends of 30-day mortality were evaluated in patients who were directly transported to CACs and in patients who were transported to non-CACs. A difference-in-difference model with repeated cross-sections was used to estimate the effect of centralization on the 30-day mortality between 2007 and 2020. The model was adjusted for additive effects of known covariates. RESULTS: A total of 14,276 patients were included. The majority of patients were aged between 50 to 75 years (57%) and 71% were male. From 2007 to 2020, the risk of 30-day mortality was reduced from 66 to 47% among patients transported to CACs and from 92 to 74% in patients transported to non-CACs. Centralization was significantly associated with an absolute risk reduction in mortality of 7% (95% CI: 2%-11%). CONCLUSIONS: In this study, a mortality decline was observed for patients transported to CACs and non-CACs. Centralization was associated with a significant reduction of the absolute 30-day mortality risk of 7% after accounting for regional differences, time-trends in patients, and OHCA characteristics.