Head Computed tomography during emergency department treat-and-release visit for headache is associated with increased risk of subsequent cerebrovascular disease hospitalization

The occurrence of head computed tomography (HCT) at emergency department (ED) visit for non-specific neurological symptoms has been associated with increased subsequent stroke risk and may be a marker of diagnostic error. We evaluate whether HCT occurrence among ED headache patients is associated with increased subsequent cerebrovascular disease risk. We conducted a retrospective cohort study of consecutive adult patients with headache who were discharged home from the ED (ED treat-and-release visit) at one multicenter institution. Patients with headache were defined as those with primary ICD-9/10-CM discharge diagnoses codes for benign headache from 9/1/2013-9/1/2018. The primary outcome of cerebrovascular disease hospitalization was identified using ICD-9/10-CM codes and confirmed via chart review. We matched headache patients who had a HCT (exposed) to those who did not have a HCT (unexposed) in the ED in a one-to-one fashion using propensity score methods. Among the 28,121 adult patients with ED treat-and-release headache visit, 45.6% (n=12,811) underwent HCT. A total of 0.4% (n=111) had a cerebrovascular hospitalization within 365 days of index visit. Using propensity score matching, 80.4% (n=10,296) of exposed patients were matched to unexposed. Exposed patients had increased risk of cerebrovascular hospitalization at 365 days (RR: 1.65: 95% CI: 1.18-2.31) and 180 days (RR: 1.62; 95% CI: 1.06-2.49); risk of cerebrovascular hospitalization was not increased at 90 or 30 days. Having a HCT performed at ED treat-and-release headache visit is associated with increased risk of subsequent cerebrovascular disease. Future work to improve cerebrovascular disease prevention strategies in this subset of headache patients is warranted.