Valuation of the Alzheimer’s Disease 5 Dimensions Instrument: A Discrete Choice Experiment With Life Duration in Chile

Abstract

Objectives

To estimate utility weights for the Alzheimer’s Disease 5 Dimensions (AD-5D) instrument in the Chilean population to obtain health utilities.

Methods

A panel sample of the Chilean population was recruited online to complete a discrete choice experiment with time duration. Weights were built based on region of residence, gender, age, and educational level. The experimental design comprised 20 blocks, each composed of 12 choice sets. In each choice set, participants compared 2 health states described by the 5 AD-5D dimensions and the life duration. A multinomial logit model was used to analyze the data, and preference parameters were anchored to the health utility scale to produce utility weights that can be used to estimate quality-adjusted life years.

Results

The study included 1895 participants who completed the discrete choice tasks. The weighted sample showed that the respondents were more educated than the general population of Chile. However, other characteristics were comparable. The Physical Health dimension had the greatest impact on utility, followed by Living Situation, Mood, Memory, and Ability to do things for fun. The health utility values ranged from 1 to −1.09, with 23% of health states having negative utilities.

Conclusions

To our knowledge, this study provides the first AD-5D utility weights for the Chilean population to be used in trials, healthcare, and economic evaluations of dementia-related interventions. Because the AD-5D instrument is based on the Quality of Life Alzheimer’s Disease Instrument, the estimated health utility weights allow estimation of quality-adjusted life years whenever the Quality of Life Alzheimer’s Disease is available.