Background: The time point generally recognized as most appropriate to assess final functional outcome after acute ischemic stroke is 3 months. However, identifying earlier reliable prognostic time points may allay patient anxiety about the recovery process, enable assignment of outcome in patients lost to follow-up, and provide earlier and more readily available options for clinical outcome assessment in adaptive design and proof of concept studies. We assessed whether day-7/10 functional outcome predicted day-90 functional outcome among acute ischemic stroke patients.
Methods: The NINDS-tPA Study database was analyzed. Global disability was assessed using the modified Rankin Scale (mRS). Spearman correlation evaluated the association of day-7/10 versus day-90 mRS, and observed agreement was computed using the weighted kappa agreement, both unadjusted and adjusted by multivariable ordinal logistic modeling for demographic and clinical variables known to influence stroke outcomes.
Results: 581 subjects (93%) were alive at 7-10 days. There was strong correlation between mRS score at day 7/10 and day 90 (r = 0.81, p < 0.0001), and the weighted kappa agreement was 0.82 (p < 0.0001). In multivariable analysis, day-7/10 day mRS was independently and strongly associated with day-90 mRS, while among other baseline variables, only baseline NIH Stroke Scale score (per unit increase) and a history of congestive heart failure (CHF) were significantly associated with a worse day-90 mRS.
Conclusions: Global disability status 1 week after an index ischemic stroke strongly predicts final 3-month disability outcome. Functioning at 1 week, supplemented by initial stroke severity and CHF history information, may provide an early outcome guide useful for patient and family counseling.