In economic evaluation of healthcare interventions, utilities (also known as health state preference values) represent the strength of individuals’ preferences for different health states. These values, averaged over a population, can be viewed as valuations of health states.

Key points about utility include:

– Valuation Scale: Utilities typically range between 0 and 1, where 1 represents perfect health and 0 represents death. Negative values are possible, indicating health states perceived as worse than death.

Quality-Adjusted Life Years (QALYs): Utility values over time can be aggregated to derive QALYs, which are commonly used in economic evaluations.

– Methods of Obtaining Utilities:

– Direct Methods: Individuals directly describe and assess health states using techniques like the Standard Gamble or Time Trade-Off.

– Indirect Methods: Health states are classified using generic multi-attribute scoring systems, and utilities are derived from population surveys using utility tariffs.


– Direct Method: Using Time Trade-Off, a respondent might value living 10 years in a specific health state as equivalent to living 8 years in perfect health, assigning a utility of 0.8 to that health state.

– Indirect Method: Using the EQ-5D instrument, a patient might report their health status across five domains, and the responses are converted to a utility score using predefined tariffs.


– Standardization: Allows for consistent and comparable measurement of health outcomes across different interventions and disease areas.

– Comprehensive Evaluation: Captures both quality and quantity of life, making it a robust measure for economic evaluations.


– Variability: Different populations may value health states differently, leading to variability in utility scores.

– Complexity: Deriving utilities, especially through direct methods, can be complex and resource-intensive.

Preferred Instruments:

– EQ-5D: The most commonly used multi-attribute utility instrument, preferred by UK NICE. It includes domains of mobility, self-care, usual activities, pain/discomfort, and anxiety/depression.

Utilities are fundamental in economic evaluations, providing a standardized way to measure and compare the effectiveness of healthcare interventions.