Objective: To estimate the value of informal care in Alzheimer's disease using contingent valuation.
Methods: A questionnaire was administered to 517 primary carers in four countries (UK, Spain, Sweden, and US). Dichotomous choice and bidding game methods were used to elicit their willingness to pay for a reduction in care burden by 1 h per day, or a total elimination of care needs. Further, the relationship between carer willingness to pay and carer and patient characteristics including disease severity and income was examined.