Abstract 183: Association of Hospital-Level Factors With Variation in Survival After Out-Of-Hospital Cardiac Arrest Between Receiving Hospitals in Japan

Abstract

Background: Patient outcomes after out-of-hospital cardiac arrest (OHCA) varies at multiple levels (geographic regions, emergency medical service agencies, and receiving hospitals). However, the contribution of hospital-level factors to the outcome variation is unclear. We aimed to investigate the association between hospital-level factors and variation in outcomes after OHCA between hospitals. Methods: We performed secondary analysis of the Japanese Association for Acute Medicine OHCA Registry, a prospective multi-center registry. We included adults (≥18 years) with OHCA of medical origin between June 2014 and December 2015. The primary outcome was 1-month survival and secondary outcome was 1-month survival with favorable functional status, defined as Cerebral Performance Category scale 1 or 2. We constructed two multivariable hierarchical logistic regression models for each outcome: (1) patient-level factors and (2) patient- and hospital-level factors. Hospital-level factors included the number of medical staff involved in resuscitation, proportion of patients who received targeted temperature management among those with return of spontaneous circulation, and proportion of patients who received extracorporeal cardiopulmonary resuscitation among those with shockable rhythm. We calculated adjusted outcomes for each hospital and median odds ratios (MORs) to evaluate the effects of hospital-level factors on between-hospital variation in outcomes. Results: We analyzed the data of 9,303 adults with OHCA of medical origin treated at 67 hospitals. After adjustment for patient-level factors, 1-month survival was 0.02-0.14 (adjusted MOR, 1.36; 95% credible interval (CI), 1.17-1.77). After adjustment for patient- and hospital-level factors, the adjusted MOR was 1.14 (95% CI, 1.05-1.33). Similarly, the adjusted MORs for favorable functional outcomes were 1.48 (95% CI 1.18-2.12) with adjustment for patient-level factors and 1.30 (95% CI 1.07-1.80) with adjustment for patient- and hospital-level factors. Conclusions: With adjustment for hospital-level factors, we noted attenuation of variation in patient outcomes after OHCA across hospitals, suggesting that hospital-level factors may partly explain outcome variations.