Dementia diagnosis underreporting is common and associated with reduced care engagement

1. In this retrospective cohort study involving older adults with probable dementia and a claims-based diagnosis, underreporting of dementia was substantially more common than underreporting of other diagnosed chronic conditions. 

2. Dementia underreporting was associated with patient and care-delivery factors and with lower postdiagnosis care engagement and planning. 

Evidence Rating Level: 2 (Good)

Study Rundown: Early dementia diagnosis can provide patients and families with time to access support services, participate in medical decisions, and address future legal, financial, and care needs. However, these benefits are dependent on effective communication and understanding by the patient or caregiver. Diagnostic uncertainty, stigma, or difficulty recognizing cognitive impairment may create a gap between documentation in the medical record and patient awareness. Previous research has largely focused on dementia that remains clinically undiagnosed, with less known about underreporting among patients who already have a documented diagnosis. Hence, this population-based cohort study used Medicare-linked Health and Retirement Study data to examine dementia diagnosis underreporting among older adults with probable dementia. Overall, dementia underreporting was considerably more common than underreporting of arthritis, hypertension, diabetes, or depression and remained frequent after dementia onset. Underreporting was associated with social vulnerability, cognitive and functional characteristics, and the setting in which the diagnosis was documented. Patients who underreported dementia were also less likely to attend a problem-based medical visit, receive an influenza vaccination, or have a witnessed will or trust following diagnosis. Interpretation was limited by reliance on claims and self-reported diagnoses as well as the inability to distinguish specific contributions of stigma, inadequate disclosure, impaired recall, and diagnosis nonacceptance. Nonetheless, this study suggests that dementia detection should be accompanied by clear diagnostic disclosure and structured postdiagnosis support to translate early identification into actionable care. 

Click to read the study in JAMA

Relevant Reading: Underdiagnosis of Dementia: An Observational Study of Patterns in Diagnosis and Awareness in US Older Adults. 

In-Depth [retrospective cohort study]: This retrospective cohort study analyzed Health and Retirement Study survey waves from 1998 through 2020 linked with Medicare claims. Participants were adults 65 years of age or older who had probable dementia according to the validated Langa-Weir cognitive classification and a dementia diagnosis recorded in Medicare claims. A total of 3278 individuals contributed 6158 person-waves, with each person-wave representing one participant’s data at a particular survey assessment. Overall, 49.1% of person-waves involved adults 85 years of age or older, 69.5% involved women, and 69.1% involved non-Hispanic White adults. Additionally, 46.0% lived alone, 37.8% were dually eligible for Medicare and Medicaid, 55.5% used a proxy respondent, and 46.0% had received care from a dementia specialist. Underreporting was defined as not reporting that a physician had diagnosed dementia or a memory-related condition despite having a claims-based dementia diagnosis during the preceding 2-year survey interval. The adjusted proportion underreporting dementia was 42% among all respondents (95% confidence interval [CI], 40% to 43%) and 67% among self-respondents (95% CI, 64% to 69%). Among self-respondents, underreporting was lower for arthritis at 17% (95% CI, 15% to 18%), hypertension at 23% (95% CI, 21% to 24%), diabetes at 39% (95% CI, 37% to 41%), and depression at 46% (95% CI, 43% to 48%). Among self-respondents, living alone (odds ratio [OR], 1.65; 95% CI, 1.27 to 2.13), non-Hispanic Black race compared with non-Hispanic White race (OR, 1.42; 95% CI, 1.01 to 2.00), and a higher cognitive score (OR per point, 1.14; 95% CI, 1.11 to 1.18) were associated with greater odds of underreporting. In contrast, a dementia specialist visit (OR, 0.64; 95% CI, 0.50 to 0.82) was associated with lower odds. Underreporting was associated with lower odds of a postdiagnosis problem-based visit (OR, 0.70; 95% CI, 0.55 to 0.90; p=0.005), influenza vaccination (OR, 0.63; 95% CI, 0.51 to 0.77; p<0.001), and having a witnessed will or trust (OR, 0.70; 95% CI, 0.54 to 0.90; p=0.005). Sensitivity analyses using more stringent diagnostic definitions produced similar findings. Overall, these findings suggest an opportunity to improve diagnostic disclosure and postdiagnosis care engagement among persons with probable dementia.

Image: PD

©2026 2 Minute Medicine, Inc. All rights reserved. No works may be reproduced without expressed written consent from 2 Minute Medicine, Inc. Inquire about licensing here. No article should be construed as medical advice and is not intended as such by the authors or by 2 Minute Medicine, Inc.