Rescaling quality of life values from discrete choice experiments for use as QALYs: a cautionary tale
2008

Rescaling Quality of Life Values for QALYs

Sample size: 282 publication Evidence: moderate

Author Information

Author(s): Terry N. Flynn, Jordan J. Louviere, Anthony AJ Marley, Joanna Coast, Tim J. Peters

Primary Institution: University of Bristol

Hypothesis

Can ordinal tasks like discrete choice experiments accurately estimate QALY health state values?

Conclusion

Using statistical models to anchor quality of life values to death is inappropriate when respondents do not conform to conventional random utility theory.

Supporting Evidence

  • Only 26% of respondents conformed to conventional random utility theory.
  • At least 14% of respondents violated the assumptions of the theory.
  • Varying the proportions of conforming respondents led to significant changes in estimated QALY values.

Takeaway

This study shows that some people think all life is worth living, which makes it hard to measure how bad a state is compared to death.

Methodology

Data from the ICECAP valuation exercise were analyzed using an ordinal model and bootstrapping to estimate QALY-like values.

Potential Biases

The model may not accurately reflect the preferences of individuals who consider all life worth living.

Limitations

The true proportion of people unwilling to consider any ICECAP state to be worse than death was unknown.

Participant Demographics

Participants were aged 65 and over, sampled from the Health Survey for England.

Digital Object Identifier (DOI)

10.1186/1478-7954-6-6

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