Pilot Evaluation of a Dementia Case Finding Clinical Service Using the Informant AD8 for At-Risk Older Adults in Primary Health Care: A Brief Report

Background: An AD8 cut-off score of ≥4 has been reported to successfully detect 90% of dementia cases in elderly patients aged 75 years and above.

Objective: We investigated the benefits of a pilot clinical service conducted in primary care that used the AD8 to identify patients with dementia in an at-risk population.

Method: Patients ≥75 years of age were recruited from a primary health care center in Singapore. Trained nurses administered the AD8 to informants of eligible patients. Patients screened positive (AD8 score ≥4) were referred to specialist memory clinics by primary health care physicians for further evaluation.

Results: Of the 551 eligible patients in the primary health care center, 168 (30.5%) consented and the AD8 was administered to their informants. Among the recruited patients, 23 (13.7%) were screened positive and 7 (30.4%) of them accepted referrals to specialist memory clinics. The clinical diagnoses for these patients were as follows: no cognitive impairment (NCI) (n = 1), cognitive impairment no dementia (CIND) (n = 5), and dementia (n = 1). Most of the (98.8%) nurses found AD8 user-friendly and could track functional decline. Eighteen of the 23 (78.3%) primary health care physicians who referred patients to specialist memory clinics considered the AD8 useful for facilitating referrals. The remaining physicians (21.7%) preferred performance-based tests.

Conclusion: The AD8 is easily administered by nurses and useful to a majority of primary health care physicians to generate referrals. However, physician preference for performance-based tests and a lower prevalence of dementia in the at-risk population may indicate the need to consider a "2-pronged assessment approach" that combines both performance-based and informant-based brief tests to reduce false positive rates and better detect dementia.