Oxford cognitive screen: A critical review and independent psychometric evaluation

Abstract

The Oxford cognitive screen (OCS) is a stroke-specific cognitive screening assessment. Although the test developers have provided psychometric information for the assessment, the OCS has received minimal external scrutiny, with which to triangulate the underpinning psychometrics. The purpose of this study is to provide a critical review and independent validation of the OCS. This study analysed data from an anonymised clinical database, which consisted of 316 patients who were assessed using the OCS on an Acute Stroke Unit. The rates of impairment on tests of memory and receptive communication were lower than expectation, suggesting that these subtests may be relatively insensitive. Patients with aphasia were more likely to be unable to categorised as impaired on non-language tests, suggesting that they remain sensitive to language processing or non-dominant hand usage. Some of the subtests of the OCS achieve high retest reliability, which makes them good candidates for measuring cognitive change over time. Although the OCS has many advantages, it is also important to adequately consider its limitations, that is insensitivity to memory problems, the potential confounding impact of non-dominant hand usage, and the potential that some tests may sample overall cognitive ability instead of domain-specific functioning.