Regional variation in temperature control after out-of-hospital cardiac arrest

Introduction: We evaluated hospitals for variation in temperature control (TC) use after out-of-hospital cardiac arrest (OHCA) in a regional emergency medical services system and assessed association of hospital-level TC utilization with survival. Methods: A retrospective cohort study of adults with non-traumatic OHCA who survived to hospital admission from 2016 to 2018 in King County, Washington. Hospitals with < 80 OHCA cases were excluded. Primary exposure was hospital-level proportion of TC. Measured outcomes were survival to hospital discharge and neurologically favorable survival (defined as Cerebral Performance Category 1 or 2). Logistic regression modeling clustered patients by treating hospital and evaluated associations between TC and outcomes with covariate adjustment. Results: Of 1,035 eligible patients admitted to eight hospitals, 69% were male, 38% had an initial shockable rhythm, and 61% had presumed cardiac etiology for OHCA. TC was initiated in 787 patients (74%) and ranged from 57 to 87% across hospitals. Overall, 34% of patients survived neurologically intact, 74% of whom received TC. In the adjusted model, public OHCA location (OR: 1.7 [95% CI 1.3-2.3]), witnessed arrest (OR: 1.6 [1.2-2.2]), and shockable rhythm (OR: 5.5 [3.9-7.8]) were more strongly associated with survival than TC utilization (OR: 0.6 [0.4-0.8]). Similar results were seen for neurologically favorable survival and did not vary significantly by hospital. Conclusions: Hospital-level TC utilization was not associated with improved survival or neurologically favorable survival after OHCA. Future studies should examine which aspects of the post-cardiac arrest care bundle most strongly influence outcomes.