Expected and diagnosed rates of mild cognitive impairment and dementia in the U.S. Medicare population: observational analysis

Abstract

Background With the emergence of disease-modifying Alzheimer’s treatments, timely detection of early-stage disease is more important than ever, as the treatment will not be indicated for later stages. Contemporary population-level data for detection rates of mild cognitive impairment (MCI), the stage at which treatment would ideally start, are lacking, and detection rates for dementia are only available for subsets of the Medicare population. We sought to compare documented diagnosis rates of MCI and dementia in the full Medicare population with expected rates based on a predictive model. Methods We performed an observational analysis of Medicare beneficiaries aged 65 and older with a near-continuous enrollment over a 3-year observation window or until death using 100% of the Medicare fee-for-service or Medicare Advantage Plans beneficiaries from 2015 to 2019. Actual diagnoses for MCI and dementia were derived from ICD-10 codes documented in those data. We used the 2000–2016 data of the Health and Retirement Study to develop a prediction model for expected diagnoses for the included population. The ratios between actually diagnosed cases of MCI and dementia over number of cases expected, the observed over expected ratio, reflects the detection rate. Results Although detection rates for MCI cases increased from 2015 to 2019 (0.062 to 0.079), the results mean that 7.4 of 8 million (92%) expected MCI cases remained undiagnosed. The detection rate for MCI was 0.039 and 0.048 in Black and Hispanic beneficiaries, respectively, compared with 0.098 in non-Hispanic White beneficiaries. Individuals dually eligible for Medicare and Medicaid had lower estimated detection rates than their Medicare-only counterparts for MCI (0.056 vs 0.085). Dementia was diagnosed more frequently than expected (1.086 to 1.104) from 2015 to 2019, mostly in non-Hispanic White beneficiaries (1.367) compared with 0.696 in Black beneficiaries and 0.758 in Hispanic beneficiaries. Conclusions These results highlight the need to increase the overall detection rates of MCI and of dementia particularly in socioeconomically disadvantaged groups.

State Department of Motor Vehicles Reporting Mandates of Dementia Diagnoses and Dementia Underdiagnosis

“…The accuracy rate of the model was 79.2%. Additional performance measures are displayed in eTable 1 in Supplement 1 …”

“…Based on the state of their office location, 223 036 primary care clinicians were assigned to the following categories: mandated clinician reporting, mandated driver self-reporting, or no explicit requirements. We used the following covariates that are potentially associated with a clinician’s probability of underdiagnosing dementia: sex, office location (metropolitan area, micropolitan area, small town, and rural area), practice specialty (internal medicine, geriatric medicine, family practice and other primary care, gynecology, and nurse practitioners or physician assistants), racial and ethnic composition of the patient panel (percentages of patients who are Hispanic, non-Hispanic Black, non-Hispanic White, and other races or ethnicities [American Indian or Alaska Native, Asian or Pacific Islander, unknown, and other, such as multiracial]), and percentage of the patients who were dually eligible for Medicare and Medicaid, because dually eligible patients and those belonging to racial and ethnic minority groups were shown to have a higher risk of missed dementia diagnoses . Patient characteristics, including race and ethnicity, were based on the Medicare Beneficiary Summary File, and clinician characteristics on the National Provider Identifier File, with their office location defined under the Rural-Urban Commuting Area Codes…”

“…Our unit of analysis was primary care clinicians. We used previously published methods 26,27 to identify clinicians who diagnose dementia at a significantly lower rate than the rate expected based on a predictive model, accounting for sampling error and size of patient panels.…”

Longitudinal Management of Dementia in Primary Care

“…A reported 92% of people with mild cognitive impairment 2 and more than half of patients with dementia remain undiagnosed. 3 When patients or their family members express worries about cognitive decline, a brief cognitive assessment, such as the Montreal Cognitive Assessment, 4 to define and quantify deficits in a variety of cognitive domains can either be reassuring or can indicate the need for additional workup.…”

Time-Domain Diffuse Optical Tomography for Precision Neuroscience

“…Neurocognitive and psychiatric disorders are highly prevalent and treatment expenditures are projected to increase in the coming decades ( 1, 2 ). Many emerging treatments for these disorders leverage novel mechanisms of action from scientific research for improved clinical results.…”