The Queen Square cognitive assessment screen (Q-CAS): normative data and validation in acute stroke

Area of Science:

• Neurology
• Neuropsychology
• Cognitive Science

Background:

• Accurate cognitive assessment post-stroke is vital for diagnosis and rehabilitation.
• Current screening tools often lack comprehensiveness, demographic consideration, or brevity.
• Neuropsychological assessments are not always feasible in clinical settings.

Purpose of the Study:

• To develop and validate the Quick Cognitive Assessment System (Q-CAS) as a brief, comprehensive cognitive screening tool for stroke.
• To evaluate the Q-CAS's reliability, validity, and diagnostic accuracy in healthy individuals and acute stroke patients.
• To address limitations of existing tools by incorporating demographic variables and assessing multiple cognitive domains.

Main Methods:

• The Q-CAS was created by adapting validated neuropsychological tests covering memory, naming, perception, attention, executive functions, processing speed, and mood.
• The tool was administered to 648 healthy individuals and 150 acute stroke patients.
• Reliability, convergent/divergent validity, and diagnostic accuracy were assessed against reference neuropsychological testing.

Main Results:

• The Q-CAS demonstrated clinically acceptable convergent and divergent validity across all subtests.
• Completion times averaged 9 minutes for healthy individuals and 15 minutes for stroke patients.
• A novel scoring method incorporating demographic variables, executive function, speed, and memory showed high sensitivity (>0.8), while perception and attention showed high specificity (>0.8).

Conclusions:

• The Q-CAS is a brief, validated cognitive screening tool for acute stroke, assessing six core domains and mood.
• It provides good diagnostic discrimination across cognitive domains, comparable for left- and right-hemisphere lesions.
• The Q-CAS offers a practical, thorough, and brief first-line approach to cognitive assessment after stroke.