Updating the model for Risk-Standardizing survival for In-Hospital cardiac arrest to facilitate hospital comparisons

Background: Risk-standardized survival rates (RSSR) for in-hospital cardiac arrest (IHCA) have been widely used for hospital benchmarking and research. The novel coronavirus 2019 (COVID-19) pandemic has led to a substantial decline in IHCA survival as COVID-19 infection is associated with markedly lower survival. Therefore, there is a need to update the model for computing RSSRs for IHCA given the COVID-19 pandemic.

Methods: Within Get With The Guidelines®-Resuscitation, we identified 53,922 adult patients with IHCA from March, 2020 to December, 2021 (the COVID-19 era). Using hierarchical logistic regression, we derived and validated an updated model for survival to hospital discharge and compared the performance of this updated RSSR model with the previous model.

Results: The survival rate was 21.0% and 20.8% for the derivation and validation cohorts, respectively. The model had good discrimination (C-statistic 0.72) and excellent calibration. The updated parsimonious model comprised 13 variables-all 9 predictors in the original model as well as 4 additional predictors, including COVID-19 infection status. When applied to data from the pre-pandemic period of 2018-2019, there was a strong correlation (r = 0.993) between RSSRs obtained from the updated and the previous models.

Conclusion: We have derived and validated an updated model to risk-standardize hospital rates of survival for IHCA. The updated model yielded RSSRs that were similar to the initial model for IHCAs in the pre-pandemic period and can be used for supporting ongoing efforts to benchmark hospitals and facilitate research that uses data from either before or after the emergence of COVID-19.