Disease staging and milestones.

This new section to the guidelines was added due to the recognition that clinical milestones are useful indices of the progression of dementia in patients with Alzheimer's disease and could help in the development of stage-specific targeted therapy. This review specifically looks at clinical milestones that could be used in clinical trials, such as global function, function, behaviour, caregiver burden, and quality of life milestones. It also addresses the possible use of biological and surrogate markers for use as milestones--which may eventually replace clinical milestones. It concludes that current definitions of dementia must be broadened beyond cognition alone to include some of the domains listed.