Early Versus Late Assessment of Stroke Outcome

What is the best timing for outcome assessment in patients with severe stroke in randomized controlled trials; early assessment at 3 months versus later at 6 to 12 months?Kennedy R. LeesThe purpose of a clinical trial is usually to assess whether and to what extent a treatment improves outcome and to identify the type and frequency of any associated risks. The question that is posed here refers only to acute trials, in which enrollment occurs within hours after stroke onset and treatment is exhibited and probably completed within at most a few days. We can reasonably assume that the treatment exerts its beneficial effect only while it is being administered and that any adverse effects are similarly acute in onset.Patients with acute stroke, and especially patients with severe stroke, are typically elderly and have elevated risk of cardiovascular disease; indeed, stroke survivors are more likely to die from cardiovascular disease than recurrent stroke. Long-term follow-up will dilute effects of treatment with other events that are part of the natural history of the condition. Any benefit may be revealed reasonably quickly, but with extended follow-up, there is an inevitable convergence of outcomes between treatment groups as complications of age, and associated risk factors come into play. We must, therefore, look at the natural history of outcomes after stroke, especially among patients with initially severe stroke, to see when recovery typically reaches its plateau at the group level.Data from the Virtual International Stroke Trials Archive, 2015 (Dr Rachael MacIsaac, personal communication) on the distribution of outcomes across 1 year assessed by modified Rankin Scale (mRS) among 159 ischemic stroke patients with admission National Institutes of Health Stroke Scale score of ≥20 indicate that the proportions of patients with good outcomes—mRS scores of 0, 1, 2, 3, or 4—each …