Evaluation of the American Heart Association Stroke Outcome Classification

Abstract

Background and Purpose —The purpose of this study was to evaluate the concurrent validity of the American Heart Association Stroke Outcome Classification (AHA.SOC) and compare performance of its function classification with that of the Modified Rankin Scale. Methods —The individuals in this study included the last 105 consecutive subjects who were part of a cohort of 459 stroke patients in the Kansas City Stroke Study. The patients were evaluated with a variety of standardized assessments at enrollment (within 14 days of stroke onset) and followed at 1, 3, and 6 months after stroke. Specifically, we examined validity of AHA.SOC by comparing its 3 domains (ie, Domain, Severe, and Function) with stroke severity. We correlated AHA.SOC-Function with scores of the Barthel Index, Lawton Instrumental Activities of Daily Living (IADL) Scale, and Medical Outcome Study 36-Item Short-Form Health Survey (SF-36) measures of physical function and mental health. Finally, we compared the discriminant ability of AHA.SOC-Function and the Modified Rankin Scale in assessing disability and handicap. These data were analyzed with the use of Spearman rank correlations and Kruskal-Wallis tests. Results —All 3 domains of the AHA.SOC were significantly associated with stroke severity and scores of Barthel Index, Lawton IADL, and SF-36 physical function (all P <0.001). Both AHA.SOC-Function and the Modified Rankin Scale discriminated well the disabilities and handicap measured by Barthel Index, Lawton IADL, and SF-36 physical function (all P <0.001). Conclusions —The AHA.SOC was able to capture impairments, disabilities, and handicap after stroke. The AHA.SOC-Function performed equally as well as the Modified Rankin Scale in assessing disabilities related to basic activities of daily living but differentiated slightly better than the Modified Rankin Scale in assessing disabilities/handicap related to instrumental activities of daily living. Neither the AHA.SOC-Function nor the Modified Rankin Scale captured differences in mental health after stroke.