Prevalence and progress of underdiagnosis of probable dementia: a repeated cross-sectional study in 19 European countries.

Background: Underdiagnosis of dementia remains a significant public health challenge in Europe, with nearly half of those meeting clinical criteria not receiving a formal diagnosis. Recent healthcare initiatives have aimed to improve diagnostic processes, but the extent of progress varies across countries.

Methods: We analyzed data of 10,402 participants from the Survey of Health, Ageing, and Retirement in Europe (SHARE) across 19 countries from 2011-2015 to 2015-2019. Underdiagnosis of probable dementia was defined as probable dementia (based on cognition score) without a confirmed diagnosis. Weighted logistic regression was conducted to examine temporal trends in underdiagnosis of probable dementia and to identify individual- and country-level predictors of progress in diagnosis.

Results: A significant reduction in underdiagnosis of dementia was observed between the two periods, consistent across most countries. Progress in diagnosis was modified by country-level factors such as number of psychiatrists, formal long-term care worker at home or institutions, and positron emission tomography and individual-level factors including age, education, retirement status, nursing home residency, multimorbidity, and healthcare utilization patterns.

Conclusions: The decreasing trend in underdiagnosis highlights the importance of targeted interventions including investment in psychiatric care services. Understanding remaining disparities is crucial for informing health policies and addressing inequalities to dementia diagnosis and care.