Reliability and Validity of the Oxford Visual Perception Screen in Sub-Acute Adult Stroke Survivors

Due to a lack of time-efficient standardised assessments, there is a high risk of unidentified visual perception difficulties in stroke survivors. The Oxford Visual Perception Screen (OxVPS) is a 15-minute performance-based screen for visual perception difficulties through tasks like picture naming and face recognition. In this cross-sectional study, the inter-rater reliability, convergent and discriminant validity of the OxVPS was evaluated in 161 stroke survivors in three UK rehabilitation units. Inclusion criteria were stroke survivors aged 18 years or over with sufficient understanding of English, ability to concentrate for 15-minutes, and capacity to consent. Video-recordings of OxVPS assessments were rated by an independent rater for inter-rater reliability. Convergent validity was assessed by comparing OxVPS scores with the Rivermead Perceptual Assessment Battery (RPAB), a 45–90-minute battery of visual perceptual tasks. Discriminant validity compared OxVPS scores with performance on the Blind Montreal Cognitive Assessment (MOCA-B) for cognition and with the Visual Impairment Screening Assessment (VISA) for sensory vision. Inter-rater reliability showed equivalent ratings (N=107, t(106)=-14.77, p <.001) and mean difference of -0.01 point on a 10-point scale in a Bland-Altman analysis (95% Confidence Interval [CI]: -0.14-0.13). Convergent and discriminant validity demonstrated a high correlation of .78 (N=58, 95% CI: .65-.86) between OxVPS and RPAB, lower correlations of .52 with MOCA-B scores (N=113, 95% CI: .37-.64) and .39 with VISA scores (N=110, 95% CI: .22-.54). Data indicates good inter-rater reliability and evidence that OxVPS predominantly measures visual perception difficulties (convergent validity) in stroke survivors and less so cognition or sensory vision (discriminant validity).