The validity of the Addenbrooke’s Cognitive Examination-Revised (ACE-R) in acute stroke

Background: The MMSE is commonly used as a screening instrument for cognitive impairment in stroke services. However, recent research has shown that it has poor diagnostic validity for use in this patient population. The purpose of this study was to examine the validity of the ACE-R as an alternative screening measure for use in stroke. Objectives: The first objective was to determine whether the ACE-R is more accurate than the MMSE at detecting overall cognitive impairment in stroke. The second objective was to determine the accuracy of the ACE-R subscales for detecting impairments in specific cognitive domains. Methods: This study had a cross-sectional design. 40 patients were recruited from an inpatient stroke service. They were administered the ACE-R (which includes the MMSE), and a battery of more detailed neuropsychological tests, which served as the ‘gold standard’ for classification of impairment. The diagnostic validity of the ACE-R and MMSE was determined by ROC analysis. Results: Both the MMSE and the ACE-R were found to have inadequate diagnostic validity for the detection of overall cognitive impairment. No cut-scores scores could be identified which yielded test sensitivity of >80% and specificity of >60%. Levels of specificity were particularly poor. The ACE-R subscales showed a similar pattern of performance, indicating inadequate validity for the detection of impairment in specific areas of cognitive functioning. Conclusions: There was no support for the use of the MMSE or the ACE-R when screening for cognitive impairment in acute stroke. Further research should focus on the identification of an alternative measure