The Diagnostic Pathway From Cognitive Impairment to Dementia in Japan: Quantification Using Real-World Data.

Objective: This study aimed to quantify the diagnostic pathway from cognitive impairment (CI) to dementia in Japan.

Methods: This was a real-world, cross-sectional survey of patients with CI and their physicians.

Results: Data for 1107 patients were provided by 106 physicians. Mean time from initial symptoms to the first consultation was 7.4±6.9 months; 42% of patients had moderate/severe CI at first consultation. Mean time from the first consultation to formal diagnosis was 2.9±11.0 months (1.9±8.8 mo if not referred to a secondary physician, and 5.1±14.6 mo if referred). Time from the first consultation to diagnosis was shorter with more severe CI at first consultation (P=0.0072). The highest proportion of patients were diagnosed by neurologists (45.8%). Tests or scales were used to aid diagnosis in 81.2% of patients. There was no association of disease severity and referral to a secondary physician; 30.9% of patients were referred, the majority (57.7%) to a neurologist.

Conclusions: A substantial proportion of patients with dementia in Japan experience CI for some time before consulting a physician. Government policy to increase public understanding and awareness of dementia, and a proposed dementia screening system, should increase the proportion of individuals consulting physicians before disease progression.