Researchers from the University of California, San Francisco and the University of Pittsburgh have recently published a late-life dementia risk index in the journal Neurology. Their objective was to develop a late-life dementia risk index that can accurately stratify older adults into those with a low, moderate, or high-risk of developing dementia within 6 years, using a sample group of 3,375 participants in the Cardiovascular Health Cognition Study.
Here is a link to the abstract of the article www.ncbi.nlm.nih.gov/pubmed/19439724?ordinalpos=2&itool=EntrezSystem2.PE... 
An article published by Massachusetts ADRC researcher Anand Viswanathan, MD, PhD, in Neurology (January 2009) on the impact of vascular factors on Alzheimer's disease also had a discussion related to risk indices.
Here is a link to the abstract of the article www.ncbi.nlm.nih.gov/pubmed/19171835?ordinalpos=2&itool=EntrezSystem2.PE...