# Time From Initial Community‐Based Dementia Consultation to Confirmed Diagnosis: A Retrospective Analysis

## TL;DR

This study examines how long it takes to diagnose dementia after an initial community consultation in Japan, finding that Alzheimer's disease is diagnosed faster than other dementia types.

## Contribution

The study identifies factors influencing diagnostic delays and highlights the role of community-based consultations in reducing delays for non-Alzheimer's dementia.

## Key findings

- Time to diagnosis was shorter for Alzheimer's disease compared to non-Alzheimer's dementia.
- Delays in non-Alzheimer's dementia were mainly due to longer pre-hospital intervals.
- Older age and presence of a primary care physician were linked to faster diagnoses.

## Abstract

With the launch of anti‐amyloid beta antibody drugs, physicians face the need to quickly diagnose dementia. In prehospital consultation services in Japan, the duration from memory‐related consultations to confirmed diagnosis has not been sufficiently investigated. Therefore, this study investigated the duration from initial community‐based dementia consultation to confirmed diagnosis and the factors associated with diagnostic delays across dementia subtypes.

This retrospective observational study included patients who consulted the Community Consultation Center for Citizens with Mild Cognitive Impairment and Dementia (CCCCMD) and subsequently received a confirmed dementia diagnosis at Nippon Medical School Musashi Kosugi Hospital between 2010 and 2024. Time to diagnosis was defined as the number of days from the initial CCCCMD consultation to diagnostic confirmation. We classified those who were diagnosed with dementia during outpatient visits amongst the consultees as Alzheimer disease (AD) or non‐Alzheimer disease (non‐AD). Diagnostic delay was further divided into pre‐hospital interval and in‐hospital phase. Group comparisons and multivariable Cox proportional hazards and logistic regression analyses were performed to identify factors associated with diagnostic delay.

A total of 739 patients were included: 504 with AD and 235 with non‐AD dementias. Time to diagnosis was shorter in the AD group than in the non‐AD group. This difference was primarily attributable to prolonged delays during the pre‐hospital interval amongst patients with non‐AD; however, delays during the in‐hospital diagnostic process were small and largely overlapping between the groups. Diagnosis of AD, older age, and the presence of a primary care physician were associated with a shorter time to diagnosis, whereas higher cognitive scores at the initial community consultation were associated with longer diagnostic delays.

Diagnostic delay differed substantially by dementia subtype. These findings highlight the importance of community‐based consultation pathways as key targets for reducing diagnostic delays, particularly for patients with non‐AD dementias.