TOPLINE

In a study of 500 deceased older adults with incident dementia, only 54% received a timely healthcare diagnosis; Alzheimer disease (AD) and moderate/severe limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) pathology were independently associated with higher odds of timely diagnosis.

METHODOLOGY

• Researchers conducted a retrospective cohort study linking autopsy data from Rush Alzheimer's Disease Center cohorts with Medicare claims to examine associations between neuropathology types and timely dementia diagnosis.
• A total of 500 participants (mean age, 87.8 years; 70.6% women; 94.8% non-Latino White) with incident dementia diagnosed between 1997 and 2019 were included; all had autopsy data and Medicare claims available.
• Participants were categorized as having timely diagnosis if dementia was documented in Medicare claims within 2 years before or after cohort-determined dementia onset; otherwise, they were classified as underdiagnosed.
• Neuropathologic assessments included AD pathologic diagnosis (78.8%) per National Institute on Aging-Alzheimer's Association criteria, moderate to severe LATE-NC pathology (45.2%), moderate to severe vascular pathologies (85.6%), and neocortical Lewy body (LB) pathology (22.4%).
• Multivariable logistic regression models adjusted for age at dementia onset, sex, race and ethnicity, years of education, and time from cohort-determined dementia onset to autopsy.

TAKEAWAY

• Only 272 participants (54.4%) received a timely dementia diagnosis.
• AD pathologic diagnosis was associated with increased odds of timely diagnosis (adjusted odds ratio [aOR], 1.91; P = .005). Moderate to severe LATE-NC pathology was associated with increased odds of timely diagnosis (adjusted aOR, 1.83; P = .002).
• Moderate to severe vascular pathologies and neocortical LB pathology showed no significant association with timely diagnosis.
• Participants with 3 or 4 neuropathologies had higher probability of timely diagnosis than those with 0 or 1 pathology (63% vs 43%; P < .001).

IN PRACTICE

"One likely explanation for these findings is the difference in clinical manifestations of dementia across pathology types and combinations. The healthcare system may on average be more sensitive to impairment in certain cognitive domains than others," the authors wrote.

SOURCE

The study was led by Yi Chen, Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago. It was published online on July 22, 2026, in Neurology.

LIMITATIONS

The study sample was predominantly non-Latino White and highly educated, limiting generalizability to more diverse populations. Participants were volunteers in longitudinal aging studies, which may introduce selection bias. The study could not account for all factors influencing diagnostic practice, such as provider characteristics or healthcare access barriers.

DISCLOSURES

The study was supported by grants from the National Institute on Aging. The authors reported having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.