Figure Assembly of study sample from the Vitamin Intervention in Stroke Prevention (VISP) cohort

Recruitment for the VISP cohort is described in detail elsewhere.⁹ Briefly, patients with a presumptive diagnosis of acute ischemic stroke were screened. Patients with total homocysteine levels (tHcy) that exceeded defined thresholds were randomized for treatment with high- or low-dose vitamin therapy. A random sample of eligible subjects with the highest 10% of tHcy were included in the study.