Trends and Factors Associated With Concordance Between International Classification of Diseases, Ninth and Tenth Revision, Clinical Modification Codes and Stroke Clinical Diagnoses

Abstract

Background and Purpose— International Classification of Diseases, Ninth and Tenth Revision, Clinical Modification ( ICD-9-CM and ICD-10-CM ) codes are often used for disease surveillance. We examined changes in concordance between ICD-CM codes and clinical diagnoses before and after the transition to ICD-10-CM in the United States (October 1, 2015), and determined if there were systematic variations in concordance by patient and hospital characteristics. Methods— We included Paul Coverdell National Acute Stroke Program patient discharges from 2014 to 2017. Concordance between ICD-CM codes and the clinical diagnosis documented by the physician (assumed as accurate) was calculated for each diagnosis category: ischemic stroke, transient ischemic attack, subarachnoid hemorrhage, and intracerebral hemorrhage. Results— In total, 314 857 patient records were included in the analysis (n=280 hospitals), 55.9% of which were obtained after the transition to ICD-10-CM . While concordance was generally high, a small, and temporary decline occurred from the last calendar quarter of ICD-9-CM (average unadjusted concordance =92.8%) to the first quarter of ICD-10-CM use (91.0%). Concordance differed by diagnosis category and was generally highest for ischemic stroke. In the analysis of ICD-10-CM records, disagreements often occurred between ischemic stroke and transient ischemic attack records and between subarachnoid and intracerebral hemorrhage records. Compared with the smallest hospitals (≤200 beds), larger hospitals had significantly higher odds of concordance (ischemic stroke adjusted odds ratio for ≥400 beds, 1.7; 95% CI, 1.5–1.9). Conclusions— This study identified a small and transient decline in concordance between ICD-CM codes and stroke clinical diagnoses during the coding transition, indicating no substantial impact on the overall identification of stroke patients. Researchers and policymakers should remain aware of potential changes in ICD-CM code accuracy over time, which may affect disease surveillance. Systematic variations in the accuracy of codes by hospital and patient characteristics have implications for quality-of-care studies and hospital comparative assessments.

Endovascular thrombectomy in acute ischemic stroke patients with COVID-19: prevalence, demographics, and outcomes

“… 9 10 We identified patients whose date of hospital discharge was from April f1 to July 31 2020 and included those with ICD-10 codes for EVT and ischemic stroke ( online supplemental table 1 ). 11 12 The concordance between the clinical diagnosis of ischemic stroke and the used ICD-10 codes has previously been shown to be >95% 11 and the codes for mechanical thrombectomy are specific to a procedure, making the use of the code without performing the procedure unlikely. Patients<18 years of age and those who were in a hospice at the time of admission were excluded.…”

COVID-19 Pandemic and Quality of Care and Outcomes of Acute Stroke Hospitalizations: the Paul Coverdell National Acute Stroke Program

“…Some patients with principal ICD-10-CM codes for stroke or TIA may not have been included in the registry. However, a study suggested that the concordance between ICD-10-CM codes and stroke clinical diagnosis was generally high in PCNASP, so misclassification would apply to a small number of patients ( 25 ). Finally, our study compared point prevalence data (pre-COVID-19 period in 2019 vs the early phase of the COVID-19 pandemic period in 2020); it did not examine the potential effects of long-term trends in stroke hospitalizations and quality of care because of the changes in the participating hospitals in PCNASP over time.…”

Characteristics and Outcomes Among US Patients Hospitalized for Ischemic Stroke Before vs During the COVID-19 Pandemic

“…This retrospective cohort study included data from the Vizient Clinical Data Base (CDB), a health care analytics platform used by participating US hospitals for measuring clinical performance, costs, and outcomes. 18 We included patients who received a diagnosis of IS (based on International Statistical Classification of Diseases, Tenth Revision, Clinical Modification [ ICD-10-CM ] codes I63.x and H34.1 19 ) who were discharged from 478 hospitals that reported complete patient-level data from January 1, 2019, to December 31, 2020. Patients were eligible for inclusion if they were admitted to the hospital on a nonelective basis and were not receiving hospice care at the time of admission.…”