Primary care expenditures before the onset of Alzheimer's disease

Objective: To investigate primary care expenditures in the period before diagnosis of AD. Methods: 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. Results: 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 ≥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. Conclusion: In addition to huge costs associated with AD after diagnosis, prediagnosis costs are an unrecognized source of expenditures related to the disease.