Abstract 184: Relationship Between Hospital Mortality and Readmission for Patients Hospitalized With Ischemic Stroke

Background: CMS publically reports hospitals’ 30-day, all-cause, risk-standardized mortality (RSMR) and readmission (RSRR) rates for several conditions and plans to use similar metrics for ischemic stroke. Although an inverse relationship in these measures (i.e., hospitals with lower mortality rates being more likely to have higher readmission rates) has not been found for acute cardiovascular disease or pneumonia, data for stroke have not been similarly analyzed. We determined whether there is an association between hospital 30-day RSMRs and RSRRs for ischemic stroke, accounting for heterogeneity across the healthcare communities in which patients receive care (i.e., hospital referral regions). Methods: We used data from CMS Hospital Compare to determine hospitals’ 30-day RSMRs and RSRRs for 2010-2013 and assessed their relationship using Pearson correlation. We then fit a mixed model with a random intercept for hospital referral region, using RSRR as the dependent variable, RSMR as the independent variable, adjustment for hospital characteristics, and weighting by hospital volume. Results: There were 2,639 hospitals with 491,105 stroke discharges during the study period. The US national 30-day RSMR was 15.3% and the RSRR was 13.4%. There was a negative relationship between the 30-day RSMRs and RSRRs (r=-0.12; p<0.001) that remained after adjustment for hospital characteristics (point estimate -0.08, 95% CI -0.06 to -0.11). This association was no longer significant after accounting for variation across hospital referral regions (point estimate -0.01; 95% CI -0.04 to 0.02). Conclusion: Unlike acute cardiovascular disease and pneumonia, there was an inverse relationship between hospitals’ RSMRs and RSRRs for ischemic stroke. The absence of this relationship after accounting for hospital referral region suggests that heterogeneity of available health services between communities plays an important role in post-discharge stroke patient outcomes.