Can Claims Diagnoses Accurately Identify Heart Failure with Reduced and Preserved Ejection Fraction in Medicare Data?

Background: Medicare claims data have been widely used to describe the management and outcomes of patients with heart failure (HF). While the management of HFrEF vs HFpEF differs, the usefulness of ICD10 codes to differentiate HFrEF and HFpEF in Medicare data is not well characterized. Thus, we assessed if ICD10 codes can accurately identify HFrEF and HFpEF in Medicare data. Methods: Among 314,221 Medicare patients hospitalized for HF (defined as primary or secondary ICD10 I50.x) between 10/2015 and 12/2017, we randomly sampled 200 charts in a 1:1:2 ratio for systolic dysfunction (I50.2), diastolic dysfunction (I50.3), and other I50.x HF. Cardiology trained physicians extracted and adjudicated clinical information. We calculated positive predictive values (PPV) with 95% confidence interval (CI) of the ICD10 codes for HFrEF and HFpEF. HFrEF was assessed using varying ejection fraction (EF) cut-offs of 40% and 50% or in combination with qualitative EF assessment. Results: Among the 314,221 HF patients, 80% had codes for systolic/diastolic dysfunction (I50.2 or 3) and 20% had codes for combined dysfunction or unspecified HF. The 200-chart-validation-sample (mean age 81, 43% male and 90% white) included 50 systolic (I50.2), 50 diastolic (I50.3), 47 combined (I50.4) and 53 unspecified HF (I50.9) patients. EF was recorded in ≥80% of patients with systolic, diastolic, and combined dysfunction. For systolic HF code, the PPV for HFrEF was 80% and 92% using EF≤40% and ≤50%, respectfully. For diastolic HF code, the PPV for HFpEF was 96% (Table). The ICD10 code for combined or unspecified HF did not predict either HFrEF or HFpEF well. Conclusion: ICD10 codes that specify systolic or diastolic HF were used in 80% of hospitalized HF patients, had EF recorded in ≥80% of patients, and predicted reduced and preserved EF with high validity. Specific ICD10 HF codes alone may be useful in identifying populations with HFrEF or HFpEF in hospitalized Medicare patients.