Using a discrete choice experiment involving cost to value a classification system measuring the quality of life impact of self-management for diabetes

D Rowen, A Labeit, K Stevens, J Elliott, B Mulhern, J Carlton, H Basarir, J Brazier

ABSTRACT

Objective:
This paper describes the use of a novel approach in health valuation of a discrete choice experiment (DCE) including a cost attribute to value a recently developed classification system for measuring the quality of life impact (both health and treatment experience) of self-management for diabetes.

Methods:
A large online survey was conducted using DCE with cost on UK respondents from the general population (n=1,497) and individuals with diabetes (n=405). The data was modelled using a conditional logit model with robust standard errors. The marginal rate of substitution (MRS) was used to generate willingness to pay estimates for every state defined by the classification system. Robustness of results was assessed by including interaction effects for household income.

Results:
There were some logical inconsistencies and insignificant coefficients for the milder levels of some attributes. There were some differences in the rank ordering of different attributes for the general population and diabetes patients. The willingness to pay to avoid the most severe state was £1,118.53 per month for the general population and £2,356.02 per month for the diabetes patient population. The results were largely robust.

Conclusion:
Health and self-management can be valued in a single classification system using DCE with cost. The MRS for key attributes can be used to inform cost-benefit analysis of self-management interventions in diabetes using results from clinical studies where this new classification system has been applied. The method shows promise, but found large willingness to pay estimates exceeding the cost levels used in the survey.