Abstract 15402: Anatomic and Physiologic Classification of Adults With Congenital Heart Disease Using International Classification of Diseases (ICD) Coding

Abstract

Background: The 2018 Adult Congenital Heart Disease (ACHD) Anatomic Physiologic (AP) classification scheme encompasses both anatomy and physiology to guide care management. To utilize the ACHD AP classification system in population-based research, an International Classification of Diseases (ICD) code-based classification is needed. Methods: AP classification of 240 cases, 18-65 years, with an encounter between 1/1/2010 - 12/31/2019 identified by at least one of 90 CHD codes (41 ICD-9-CM, 49 ICD-10-CM) in a tertiary adult healthcare system was performed by two methods - medical record review and a novel code-based AP classification. Cases were assigned one of four mutually exclusive AP classification categories based on complex vs. non-complex (simple plus moderate) anatomy and combined AB physiology (no/mild physiologic comorbidities) vs. CD physiology (moderate/severe physiologic comorbidities). A composite outcome of death, emergency department visit and/or hospitalization at 1-year after AP classification was evaluated. Results: Both record review and ICD code-based physiology classification methods demonstrated significant differences in 1-year outcomes between AB and CD physiology regardless of anatomic classification (Table 1), with CD physiology experiencing more adverse outcomes. Performance of AP classification by record review [PPV: 85.1% (97/114)] and ICD code-based classification [PPV: 80.7% (92/114)] (p=0.38) was similar. No differences were revealed by comparing outcome prediction within physiologic group by method, (AB by record review vs. AB by ICD codes: p=0.98; CD record review vs. CD by ICD codes: p=0.16). Conclusion: An ICD code-based classification of the ACHD AP guidelines is feasible, predictive of future adverse outcomes, and a reliable tool to use in administrative data. ICD code-based AB and CD physiology classifications are a good differentiator of outcomes for both complex and non-complex anatomic groups.