Use of ICD-10 Codes for Identification of Injection Drug Use–Associated Infective Endocarditis Is Nonspecific and Obscures Critical Findings on Impact of Medications for Opioid Use Disorder

Abstract

Background No International Classification of Diseases 10 th revision (ICD-10) diagnosis code exists for injection drug use-associated infective endocarditis (IDU-IE). Instead, public health researchers regularly use combinations of non-specific ICD-10 codes to identify IDU-IE; however, the accuracy of these codes has not been evaluated. Methods We compared commonly used ICD-10 diagnosis codes for IDU-IE to a prospectively collected patient cohort diagnosed with IDU-IE at Barnes-Jewish Hospital to determine the accuracy of ICD-10 diagnosis codes used in IDU-IE research Results ICD-10 diagnosis codes historically used to identify IDU-IE were inaccurate, missing 36.0% and misclassifying 56.4% of patients prospectively identified in this cohort. Use of these non-specific ICD-10 diagnosis codes resulted in substantial biases against the benefit of medications for opioid use disorder (MOUD) with relation to both AMA discharge and all-cause mortality. Specifically, when data from all patients with ICD-10 code combinations suggestive of IDU-IE was used, MOUD was associated with an increased risk of AMA discharge (RR 1.12; 95% CI 0.48 - 2.64). In contrast, when only patients confirmed by chart review as having IDU-IE were analyzed, MOUD was protective (RR 0.49; 95% CI 0.19 - 1.22). Use of MOUD was associated with a protective effect in time to all-cause mortality in Kaplan-Meier analysis only when confirmed IDU-IE cases were analyzed (p=0.007) Conclusions Studies using non-specific ICD-10 diagnosis codes for IDU-IE should be interpreted with caution. In the setting of an ongoing overdose crisis and a syndemic of infectious complications, a specific ICD-10 diagnosis code for IDU-IE is urgently needed

Temporal Trends of Infective Endocarditis in North America From 2000 to 2017—A Systematic Review

“…Moreover, there is a discrepancy in the use of surrogate codes for IE in PWID, as there are no specific ICD-9/10 codes for PWID, resulting in studies reporting varying data for hospitalization of patients for the same year using the same database [ 36 ]. Furthermore, it has been suggested that studies that use ICD-10 for coding of IE in PWID should be viewed with caution, owing to the risk of missing or misclassifying more than half the patients, prompting questions regarding the accuracy of codes [ 37 ]. This demonstrates a need for ICD codes to be standardized and validated with other records before conducting population-based studies.…”

Diagnostic accuracy of ICD code versus discharge summary-based query for endocarditis cohort identification

“…[ 11 ] Use of ICD codes without verification of event accuracy is a common practice, and few studies have validated ICD codes for IE. [ 12 – 15 ]…”

HIV detection by an emergency department HIV screening program during a regional outbreak among people who inject drugs

“…Although diagnosis codes are known to misclassify and severely underestimate ED prevalence of substance use disorders [27][28][29], we characterized the study-site ED population from 2017-2018 using International Classification of Diseases 10 th Edition (ICD-10) codes. Of ED patients, 0.7% had at least one opioid use disorder diagnosis (any F19.X), 0.3% had a diagnosis of intravenous drug use (F19.9), 1% had either a chief complaint or diagnosis code that included the terms "opioid" and "overdose", and 2% had either a chief complaint or diagnosis code that included the term "abscess" [21].…”