Abstract 16307: Does the Method of Calculating the 30-day Readmission Rate After Hospitalization for Heart Failure Matter? Data From the VancOuver CoastAL Acute Heart Failure Registry

Abstract

Introduction: The 30-day readmission rate after a heart failure (HF) hospitalization is widely used for assessing healthcare quality and system performance. However, there are different methodological approaches which may influence estimated rates, and no single accepted approach. The combined impact of these methods is unknown. Goals: We calculated 30-day HF readmission rates (RRs) of hospitalized patients using different published approaches to sampling and measurement. Methods: We included 1,849 patients discharged following unplanned hospitalization with a primary diagnosis of HF between 2016 to 2018 from the VancOuver CoastAL Acute Heart Failure (VOCAL-AHF) registry. We combined five distinct methodological factors (Table 1) to create 64 unique definitions and associated HF RRs. The readmission rates were averaged over 3-years. Multiple linear regression was used to determine the impact of different factors on estimated readmission rates. Results: The calculated 30-day RR for HF varied more than twofold depending solely on the methodological approach (6.4% to 15.0%, 8.6% absolute difference, 134% relative difference). The rates were highest when including all consecutive index admissions (11.1% to 15.0%), and lowest including only one index admission per patient per year (6.4% to 11.4%). The regression model ranked variables affecting RR as: index selection method, reference period, ICD-10 codes, 30-day survival, and index day (Table 2, p<0.001 in all). Conclusions: Our findings have important implications for policy and reporting. Transparent and consistent methods are needed to calculate 30-day RRs to ensure reproducible and comparable reporting.