This study is an imaging-based survey completed by stroke neurologists, using follow-up CT head images post-AIS, to understand variability in decision making regarding anticoagulation timing following AIS. We hypothesized that there would be more variability (lower inter-rater reliability) in anticoagulation decisions for moderate-sized infarcts and less variability (higher inter-rater reliability) for small and large volume infarcts.

A pilot imaging-based electronic survey using CT head images of 25 patients from day 1 post AIS was developed and taken by 5 stroke neurologists. With each image shown, the question “When would you initiate anticoagulation?” was asked. Stroke volumes were calculated and strokes categorized as small (0 – 14.9mL), small-medium (15 – 44.9mL), medium-large (45 – 74.9mL), or large (>75mL). Respondents were not given calculated volumes. Inter-rater reliability was determined based on interclass correlation coefficient (ICC) calculated for each question.

Preliminary data, although a small sample, suggests stroke neurologists most disagree on anticoagulation timing following small/moderate sized ischemic strokes. With large infarcts, there is more agreement for later anticoagulation initiation. Using pilot data and sample-size calculations, we developed an expanded 120-question survey which will be distributed to 30 stroke neurologists Fall 2019. We hope to better understand anticoagulation decisions and to define the population that causes the most disagreement among stroke neurologists, as a potential target for future research.