The International Classification of Diseases, 10 th Edition, Clinical Modification (ICD-10-CM) Code I16.0 Accurately Identifies Patients with Hypertensive Urgency.

Objective:Hypertensive urgency, defined as acutely elevated BP without target organ damage, is associated with an increased risk of adverse cardiovascular events and accounts for a substantial proportion of national emergency department (ED) visits. To advance research in this space, we sought to validate the new ICD-10-CM diagnostic code for hypertensive urgency within a single healthcare system. Methods:We performed a retrospective chart-review study of ED encounters at Weill Cornell Medicine from 2016 â€" 2021. We randomly selected 25 encounters with the ICD-10-CM code I16.0 as the primary discharge diagnosis and 25 encounters with primary ICD-10-CM discharge diagnosis codes for benign headache disorders. A single board-certified vascular neurologist reviewed all 50 encounters while blinded to the assigned ICD-10-CM codes to identify cases of hypertensive urgency. We calculated the sensitivity, specificity, and positive predictive values of the ICD-10-CM code I16.0 with 95% confidence intervals (CI). Results:Out of 50 randomly selected ED encounters, 24 were adjudicated as hypertensive urgency. All encounters adjudicated as hypertensive urgency had been assigned the ICD-10-CM discharge diagnosis code of I16.0. All 25 of the encounters adjudicated as headache were assigned an ICD-10-CM discharge diagnosis code for a benign headache disorder. The ICD-10-CM code for hypertensive urgency, I16.0, was thus found to have a sensitivity of 100% (95% CI: 86-100%), specificity of 96% (95% CI: 80-100%), and positive predictive value of 96% (95% CI: 78-99%). Conclusion:We found that the new ICD-10-CM code for hypertensive urgency, I16.0, can reliably identify patients with this condition.