Performance of Electronic Health Record Diagnosis Codes for Ambulatory Heart Failure Encounters.

BACKGROUND: There is interest in leveraging the electronic medical records (EMRs) to improve knowledge and understanding of patients' characteristics and outcomes of patients with ambulatory heart failure (HF). However, the diagnostic performance of International Classification of Diseases (ICD) -10 diagnosis codes from the EMRs for patients with HF and with reduced or preserved ejection fraction (HFrEF or HFpEF) in the ambulatory setting are unknown.
METHODS: We examined a cohort of patients aged ≥ 18 with at least 1 outpatient encounter for HF between January 2016 and June 2018 and an echocardiogram conducted within 180 days of the outpatient encounter for HF. We defined HFrEF encounters as those with ICD-10 codes of I50.2x (systolic heart failure); and we defined HFpEF encounters as those with ICD-10 codes of I50.3x (diastolic heart failure). The referent definitions of HFrEF and HFpEF were based on echocardiograms conducted within 180 days of the ambulatory encounter for HF
RESULTS: We examined 68,952 encounters of 14,796 unique patients with HF. The diagnostic performance parameters for HFrEF (based on ICD-10 I50.2x only) depended on LVEF cutoff, with a sensitivity ranging from 68%-72%, specificity 63%-68%, positive predictive value 47%-63%, and negative predictive value 73%-84%. The diagnostic performance parameters for HFpEF depended on left ventricular ejection fraction cut-off, with sensitivity ranging from 34%-39%, specificity 92%-94%, positive predictive value 86%-93%, and negative predictive value 39%-54%.
CONCLUSIONS: ICD-10 coding abstracted from the EMR for HFrEF vs HFpEF in the ambulatory setting had suboptimal diagnostic performance and, thus, should not be used alone to examine HFrEF and HFpEF in the ambulatory setting.