Abstract WMP91: Head CT at Emergency Department Treat-and-Release Visit for Headache is Associated With Increased Risk of Subsequent Hospitalization for Cerebrovascular Disease

Abstract

Background: Headache is a common presenting symptom among patients with misdiagnosed cerebrovascular (CVD) disease. Recent studies report that the occurrence of a head CT (HCT) during emergency department (ED) visit for non-specific neurological symptoms, such as vertigo, is associated with increased risk of stroke after ED discharge. We sought to evaluate whether the occurrence of HCT at ED visit for headache is associated with increased CVD risk. Hypothesis: Patients with headache complaints who have a HCT performed in the ED (exposed) are more likely to have a CVD admission within 365 days of ED discharge than those who do not receive a HCT (unexposed). Methods: We conducted a retrospective study of consecutive adult patients with headache complaints discharged to home (treat-and-release visit) from all four of the EDs affiliated with a single academic institution. Patients with headache complaints were defined as those with primary ICD-9/10-CM discharge diagnosis of benign headache; patients were included in our study at their first ED treat-and-release visit from 2013 to 2018. Subsequent CVD hospitalizations were identified using ICD-9/10-CM inpatient discharge codes and confirmed via chart review. We matched exposed to unexposed patients in a one-to-one fashion using propensity score methods. Standard descriptive statistics and relative risk (RR) with 95% CIs are reported. Results: Among 28,121 patients with an ED treat-and-release visit for headache complaints, 45.6% (n=12,812) underwent HCT during ED visit. A total of 0.4% (n=112) patients had a subsequent CVD admission within 365 days of ED visit. Using propensity score matching, 80.3% (n=10,295) of patients with HCT (exposed) were able to be matched. In the matched sample, exposed patients had a nearly two-fold increased relative risk of CVD at 365 days (RR: 1.83; 95% CI: 1.12-3.01). In secondary analysis, CVD risk at 180 days was also higher in exposed (RR: 2.06; 95% CI: 1.13-3.74). Conclusion: Having a HCT performed at index ED treat-and-release visit among those with headache complaints establishes a clinically meaningful risk gradient for subsequent CVD hospitalization. Some ED patients given a headache diagnosis may have been misdiagnosed at index visit.