In a population-based, propensity score-weighted, retrospective cohort study, "Association of Alternative Anticoagulation Strategies and Outcomes in Patients With Ischemic Stroke While Taking a Direct Oral Anticoagulant," Ip et al. retrospectively identified 2,337 patients with nonvalvular atrial fibrillation who had an ischemic stroke while on a direct oral anticoagulant (DOAC) admitted to public hospitals in Hong Kong from 2015 to 2020 and compared outcomes in patients who were switched to other antithrombotic regimens vs those who were kept on the same DOAC. They found that compared with continuing the same DOAC, switching to warfarin or another DOAC was associated with increased risk of stroke. Among those who remained on the same DOAC, adjunctive antiplatelet agents did not reduce the recurrence risk. Wolfe and Siegler wondered about the mechanism for recurrent stroke and the accuracy of demographic reporting in these patients, as anticoagulant selection would be unlikely to mediate recurrent stroke risk due to risk factors, such as intracranial atherosclerosis and tobacco use. They noted that in a previous study of 691 patients with acute transient ischemic attack or minor stroke from 2011 to 2015 at the Chinese University of Hong Kong, Leng et al. demonstrated that 43% of patients had intracranial atherosclerosis and 39% of patients used tobacco (versus <3% and <1%, respectively, in the cohort of Ip et al). The authors responded that the low percentage of patients with intracranial atherosclerosis in their cohort could be attributed to both the overall decline in intracranial atherosclerosis in Hong Kong from 2004 to 2018 and underinvestigation of intracranial vessels in patients with presumed cardioembolic stroke. They also noted that their data on tobacco use were specific to the period of time after the first stroke, by which point many had quit (while Leng et al. recorded lifetime tobacco use) and that smoking prevalence in Hong Kong has been gradually declining. This exchange highlights the challenges of accounting for confounding stroke risk factors in studies of stroke recurrence in patients with nonvalvular atrial fibrillation. Additional research is needed on the association of anticoagulation strategies for secondary stroke prophylaxis with careful consideration of demographic factors and investigation of stroke mechanism.