OBJECTIVES : Little is known about the costs associated with the prodromal stages of dementia. The aim of this study is to estimate primary care costs triggered by Alzheimer disease (AD) prodromal signs and/or symptoms, during a 10-year or longer period preceding AD diagnosis, and compared them with costs cumulated in general population for the same signs and/or symptoms.

METHODS : This is a cohort study with a nested case-control analysis involving 1889 AD cases and 18890 controls aged 60 years or older, gathered from the Health Search Database (HSD), an Italian data source collecting primary care data. AD incident cases have been defined in accordance with ICD-9CM codes. Costs related to pharmacological treatment, diagnostic tests and specialist referrals triggered by prodromal AD signs and/or symptoms have been quantified and compared with costs cumulated by the same conditions in the general population aged 60 years or older

RESULTS : In primary care patients developing AD, during the pre-diagnosis 10-year or longer period, prodromal signs and symptoms trigger diagnostic and therapeutic costs that are 55% significantly higher than those cumulated in general population for the same clinical reasons. After accounting for patients’ comorbidity burden and regional differences, the mean cost related to diagnostic and therapeutic procedures, and those related to specialist referrals, amounted to 854.1 € (SD: 630.6 €) in AD incident cases vs. 527.3 € (SD: 446.2) in control cases.

CONCLUSIONS : Prodromal AD manifestations are associated to primary care costs that resulted higher than those cumulated in the general population aged 60 years or older for the same clinical reasons. A better interpretation of such signs and symptoms might aid GPs to set more precise and timely diagnostic pathways, as well as health care systems to optimize resource allocation when planning prevention and care paths for people at risk of cognitive decline.