Estimating a preference-based single index 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
Self-management is becoming increasingly important in diabetes, but is neglected in conventional preference-based measures. The objective of this paper is to generate health state utility values for a novel classification system measuring the quality of life impact of self-management for diabetes, that can be used to generate Quality Adjusted Life Years (QALYs).
A large online survey was conducted using a discrete choice experiment (DCE) with duration as an additional attribute on members of the UK general population (n=1,493) to elicit values for health (social limitations, mood, vitality, hypoglycaemia) and non-health (stress, hassle, control, support) aspects of self-management in diabetes. The data was modelled using a conditional fixed-effects logit model and utility estimates were anchored on the 1-0 full health-dead scale. Robustness analyses were conducted excluding very quick responses.
The model produced significant and consistent coefficients, with one logical inconsistency and three insignificant coefficients for the milder levels of some attributes. The anchored utilities range from 1 for the best state to -0.029 for the worst state (meaning worse than dead) defined by the classification system. The results were largely robust.
Health and self-management can be valued in a single classification system and both can be represented using a single utility value to generate quality adjusted life years (QALYs). The results presented here can be used in economic models of the cost-effectiveness of new interventions to value the day to day impact of the interventions for health and self-management of diabetes.