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 limitations exist in comprehensive, practical cognitive screening tools for stroke patients.
• Existing tools often fail to cover all relevant domains, account for demographics, or be brief.

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 assess the reliability, validity, and diagnostic accuracy of Q-CAS in healthy individuals and acute stroke patients.

Main Methods:

• Developed Q-CAS by adapting validated neuropsychological tests covering memory, naming, perception, attention, executive functions, processing speed, and mood.
• Administered Q-CAS to 648 healthy individuals and 150 acute stroke patients.
• Evaluated reliability, convergent/divergent validity, and diagnostic accuracy against standard neuropsychological testing.

Main Results:

• Q-CAS completion time averaged 9 minutes for healthy individuals and 15 minutes for stroke patients.
• All subtests showed acceptable convergent and divergent validity.
• A novel scoring method incorporating demographics, executive function, speed, and memory demonstrated high sensitivity (>0.8).

Conclusions:

• Q-CAS is a brief, validated cognitive screening tool for acute stroke, assessing six core domains and mood.
• It provides good discrimination across cognitive domains and is a practical first-line assessment.
• Q-CAS overcomes limitations of existing tools by balancing brevity and thoroughness.