The ABCD2 score is a clinical prediction rule used to determine the risk for stroke in the days following a transient ischemic attack (TIA, a condition in which temporary brain dysfunction results from oxygen shortage in the brain). Its usefulness was questioned in a 2015 review as it was not found to separate those who are at low from those who are at high risk of future problems. A high score correctly predicted 87% of the people who did have a stroke in the following 7 days but also many people who did not have problems.