Validation of the self-rated Dimensional Apathy Scale in community stroke survivors

Abstract

Apathy, a disorder of motivation observed in up to 40% of stroke survivors, is negatively associated with stroke rehabilitation outcomes. Different apathy subtypes have been identified in other conditions, but there is currently no validated multidimensional measure of post-stroke apathy (PSAp). The Dimensional Apathy Scale (DAS) assesses apathy across three subtypes: Executive, Emotional and Initiation apathy. We aimed to determine if the DAS is a reliable and valid tool to detect and characterise apathy in stroke. Fifty-three stroke survivors, (45.3% males, median age 54), and 71 people without stroke (26.8% males, median age 45) completed measures of apathy (DAS, Apathy Evaluation Scale, AES), depression (Patient Hospital Questionnaire, PHQ-9) and anxiety (Generalised Anxiety Disorder scale, GAD-7) as part of an online survey. The DAS showed high internal consistency and convergent validity with the current gold standard unidimensional assessment for apathy (AES) and divergent validity with depression (PHQ-9) and anxiety (GAD-7). Stroke survivors scored significantly higher on the total score of the DAS and all subscales, compared with controls. There were however no significant differences on depression and anxiety scores between the two groups. Our results suggest the DAS is a reliable and valid screening tool to detect and characterise PSAp.