AbstractBackgroundIntravenous thrombolysis (IVT) in acute ischemic stroke (AIS) is a time‐dependent treatment with a narrow therapeutic time window, in which the time delay could result from the deadline effect.MethodsOne hospital‐based cohort was recruited to detect the factors contributing to the deadline effect, where patients with the deadline effect were defined as those who were presented with the onset‐to‐door time (ODT) in the first 50%, while the door‐to‐needle time (DNT) was in the last quartile. DNT (in‐hospital delay) was further subdivided into several time intervals [door‐to‐examination time (DET), door‐to‐imaging time (DIT), door‐to‐laboratory time (DLT), and decision‐making time (DMT) of the patients or their proxies.ResultsA total of 186 IVT cases were enrolled, of which 17.2% (32/186) suffered a delay of the deadline effect. The median age was 66 years, and 35.5% were female. Baseline characteristics were similar between the two groups (allp> .05). For the comparisons of the time intervals, DIT (26 versus 15 min,p= .001) was significantly longer in the group with deadline effect, while the differences of DET, DLT, DMT, and ONT did not reach statistical significance (allp> .05). Upon multivariable adjustment in the binary logistic regression model, longer DIT [odds ratio (OR), 1.076; 95% confidence interval (CI), 1.036–1.118;p< .001], and history of coronary heart disease (OR, 3.898; 95%CI, 1.415–10.735;p =.008) were independently associated with deadline effect in the binary logistic regression model, while admitted in the working day (OR, 0.674; 95%CI, 0.096–0.907;p= .033), and having medical insurance (OR, 0.350; 95% CI, 0.132–0.931;p= .035) were negatively associated with the deadline effect.ConclusionsA speed‐safety tradeoff phenomenon from the deadline effect was observed in 17.2% of IVT cases during the COVID‐19 pandemic, where longer DIT contributed a lot to this time delay. Patients without medical insurance, or admitted in official holidays were more likely to experience a delay of the deadline effect.