Primary care expenditures before the onset of Alzheimer's disease

To investigate primary care expenditures in the period before diagnosis of AD.

In a population-based sample of Medicare enrollees in New York City, person-level 1996 Medicare claims, summed over primary care encounters, were examined for people who developed AD in 1997 to 1998 and those who did not.

People who developed AD were more likely to use Medicare outpatient and ambulatory care 1 to 2 years before diagnosis. Compared with respondents who did not develop AD, the excess cost for men was $1,167 (85% higher) and for women $239 (26% higher). Among elderly people > or = 75 years in the United States, the prodromal period of AD was associated with an excess Medicare-based primary care cost of $128.5 to $194.7 million.

In addition to huge costs associated with AD after diagnosis, prediagnosis costs are an unrecognized source of expenditures related to the disease.