Yu AYX, et al. - Researchers here determined the validity of the Canadian 10th International Classification of Diseases (ICD-10-CA) codes for Transient ischemic attack (TIA) in the national ambulatory administrative database. In this study, emergency department administrative data seemed reflecting diagnosis of suspected TIA with high specificity, but it underestimated the burden of disease. To understand the reasons for the low to moderate sensitivity, further study is recommended.