Abstract 112: Quality of Post-Resuscitation Cardiac Arrest Care: Adjustment for Case Mix and Association of Treatment Factors with Outcome
Introduction: Comparing outcomes of cardiac arrest (CA) survivors is hampered by variability of case mix and post-resuscitation practices. We developed models to correct for case mix and investigate the relationship of resource utilization to outcome.
Methods: Retrospective analysis of 754 CA survivors admitted to six interventional cardiology centers in the United States from 2006-2011. Patient characteristics, treatments, and outcomes were compared using chi-squared tests for categorical variables or ANOVA for continuous variables. Primary outcome was CPC score of 1-2 at delayed follow-up . Risk adjustment models were constructed to account for differences in patient characteristics using a hierarchal logistic model with a random site effect, and calculated risk-adjusted outcome rates with 95% confidence intervals by site. The expanded model included site as a fixed effect, and treatment variables to explain additional variability between sites.
Results: 59.8% patients had VT/VF, 97.6% received therapeutic hypothermia, and 44% underwent urgent coronary angiography. Good functional outcome (CPC 1-2) was 38%, and risk adjusted outcomes ranged from 37% to 51%. Site of admission was added as a random effect, with age, number of comorbidities, initial heart rhythm, witnessed arrest, total ischemic time, suspected cardiac cause of arrest, and shock on admission. It had strong discrimination (C statistic of 0.84). Risk-adjusted rates of CPC 1-2 did not differ between sites, and risk adjustment accounted for much of the variability in outcomes between sites. Site was added as a fixed effect and the model showed EEG monitoring and urgent coronary angiography were related to better outcome. The final model had improved discrimination (C statistic of 0.89).
Conclusions: Functional outcomes after CA should be adjusted for age, heart rhythm, ischemic time, suspected cardiac cause of the arrest, witnessed arrest, and shock at admission. Urgent coronary angiography and use of EEG monitoring were associated with better outcomes. Post-resuscitation quality metrics should include these variables, and CA centers provide therapeutic hypothermia, urgent cardiac catheterization for appropriate patients, and EEG monitoring.
- © 2013 by American Heart Association, Inc.