Validity and responsiveness of generic preference-based HRQOL instruments in chronic epilepsy

Area of Science:

• Health Economics
• Psychometrics
• Neurology

Background:

• Generic, preference-based instruments are recommended for health-related quality of life (HRQOL) assessment in cost-utility analyses (CUA).
• Selecting the most appropriate HRQOL instrument for CUA in epilepsy care is crucial for accurate economic evaluations.
• Established psychometric criteria are essential for evaluating the validity and responsiveness of these instruments.

Purpose of the Study:

• To determine the most appropriate generic, preference-based instrument for CUA of epilepsy care.
• To compare the validity and responsiveness of EQ-5D, VAS, HUI-2, HUI-3, and SF-6D in adults undergoing epilepsy surgery evaluation.
• To identify the instrument with the best psychometric properties for capturing HRQOL impacts in epilepsy.

Main Methods:

• A comparative study involving 165 adults evaluated for epilepsy surgery.
• Assessment of validity and responsiveness using established psychometric criteria.
• Comparison of EQ-5D (UK and US preferences), VAS, HUI-2, HUI-3, and SF-6D, alongside the epilepsy-specific QOLIE-89.

Main Results:

• SF-6D showed the strongest associations with seizure severity and control, and discriminated between patients with and without seizures.
• SF-6D demonstrated the highest responsiveness to achieving seizure freedom.
• While VAS was responsive, it had weaker evidence of validity; QOLIE-89 showed stronger psychometric evidence than preference instruments.

Conclusions:

• SF-6D exhibits key psychometric advantages over other preference instruments for CUAs in epilepsy care.
• These advantages may stem from better coverage of epilepsy-affected HRQOL dimensions or enhanced sensitivity.
• Findings highlight SF-6D's utility but may not generalize to other chronic conditions.