Quentin W, Riedel-Heller SG, Luppa M, Rudolph A, König H-H. Cost-of-illness studies of dementia: a systematic review focusing on stage dependency of costs.Objective: To review cost-of-illness (COI) studies of dementia from Europe and North America which report costs per patient by disease stage. Method: A systematic literature search was performed in electronic databases. Studies were classified according to important determinants of costs. Results were converted into year 2006 USD-PPP, and summarized as costs for formal and informal care in mild, moderate and severe dementia. Results: 28 studies were evaluated. They used a wide range of methods. Costs more than doubled from mild to severe dementia. Patterns and size of estimated costs depended primarily on study objectives (estimation of total costs-net costs), living arrangements of patients (community-dwelling-institutionalized) and inclusion of informal care. Conclusion: This review is the first to have focused on costs in different stages of dementia. The stage is an important determinant of costs. However, characteristics of individual studies need to be considered, when making use of their results.
