Challenges to time trade-off utility assessment methods: when should you consider alternative approaches?

Area of Science:

• Health Economics
• Outcomes Research
• Psychometrics

Background:

• The time trade-off (TTO) method is a primary tool for direct health state utility assessment.
• Its frequent use, often with a 10-year horizon, is influenced by the National Institute for Health and Care Excellence's preference for EQ-5D comparability.

Purpose of the Study:

• To critically review the limitations and challenges associated with the TTO method in health utility assessment.
• To identify specific scenarios where the TTO approach may be inappropriate or yield suboptimal results.

Main Methods:

• A literature review approach was employed to identify and discuss challenges to the TTO method.
• Analysis focused on five key problematic areas: mild, small, temporary, and pediatric health states, and specific sample characteristics.

Main Results:

• The TTO method encounters significant challenges in valuing mild or subtly different health states.
• Temporary health states and pediatric populations present unique difficulties for TTO valuation.
• Certain sample characteristics can also compromise the reliability of TTO assessments, irrespective of the time horizon.

Conclusions:

• The TTO method, despite its prevalence, is not universally suitable for all health state utility assessments.
• Alternative methods for health state valuation should be considered, particularly in the identified challenging scenarios.
• Addressing these limitations is crucial for accurate and reliable health economic evaluations.