Abstract 18879: Discordance between ICD-9 Coded Myocardial Infarction and Adjudicated Diagnosis According to the Universal Definition of Myocardial Infarction
Introduction: The International Classification of Diseases (ICD) codes facilitate quality review evaluations. However, despite the global endorsement by cardiology societies, the Third Universal Definition of Myocardial Infarction (MI) subtypes remain ignored.
Objective: Using the UTROPIA (NCT02060760) cohort study, we determined the concordance for the diagnosis of MI using ICD-9 coding versus adjudication according to the Universal Definition.
Methods: We measured cardiac troponin I by both contemporary (cTnI) and high sensitivity (hs-cTnI) assays in 1927 (56% men) consecutive emergency department patients who had cTn ordered on clinical indication. All patients with at least one increased cTn by either contemporary or hs assays were adjudicated based on clinical data by 2 clinicians. We compared primary, secondary and tertiary ICD-9 diagnosis code 410 vs. type 1 (T1MI) and type 2 (T2MI) MI. Kappa index and McNemar’s test assessed the concordance between both classifications.
Results: Using the contemporary cTnI assay, for the 249 adjudicated MIs, only 69 (27.7%) were ICD-9 coded MIs. Of the 180 patients which were not ICD-9 coded as MI, 34 (18.9%) were T1MI and 146 (81.1%) as T2MI. For those coded as MI using ICD codes, 79.2% were T1MI and 20.8% as T2MI. A fair Kappa index of 0.386 (95% CI 0.319-0.452) and a McNemar’s difference of 0.0892 (p<0.001) was found. Based on the hs-cTnI assay, for the 207 adjudicated MIs, only 67 (32.4%) were ICD-9 coded MIs. Of 140 patients which were not ICD-9 coded as MI, 27 (19.3%) were T1MI and 113 (80.7%) as T2MI. For those coded as MI using ICD codes, 85.1% were T1MI 14.9% as T2MI. A moderate Kappa index of 0.439 (95% CI 0.367-0.511) and a McNemar’s difference of 0.0674 (p<0.001) was found. Agreement in cases adjudicated as non-MI was excellent, with the ICD-9 coded findings disagreeing in < 1% of patients for both assays.
Conclusions: ICD coded MIs capture a small proportion of adjudicated MI diagnoses, primarily due to not coding T2MI as ICD-coded MIs. ICD-9 codes represent a mixture of both T1MI and T2MI. These findings suggest caution when using ICD codes to assess for quality review, resource utilization and outcomes. Our findings emphasize the need for an ICD-10 code for T2MI.
Author Disclosures: J. Díaz-Garzón: None. Y. Sandoval: None. S.W. Smith: Consultant/Advisory Board; Modest; Roche. Consultant/Advisory Board; Significant; Alere, Siemens. S.A. Love: None. K. Schulz: None. S.E. Thordsen: None. B.K. Johnson: None. B. Driver: None. K. Jacoby: None. M.D. Carlson: None. K.W. Dodd: None. J. Moore: None. N.L. Scott: None. C.A. Bruen: None. F.S. Apple: Research Grant; Modest; Abbott, Siemens, Ortho-Clinical Diagnostics, Roche. Consultant/Advisory Board; Modest; Instrumentation Laboratories, Alere, T2 Biosystems, Phillips Healthcare Incubator, Metanomic Health, Abbott Point of Care. Other; Modest; Board Member HyTest.
- © 2016 by American Heart Association, Inc.