Diagnosis gap widens from symptom onset between Black, white patients

In older adults with dementia, Black patients were less likely to receive a diagnosis than white patients, with the difference increasing over 3 years following symptom onset, according to a recent study.

“Prior research has identified evidence of potential differences in the likelihood of receiving an [Alzheimer’s disease and related dementia] clinical diagnosis by race and ethnicity,” Matthew A. Davis, MPH, PhD, of the department of systems, populations and leadership at the University of Michigan School of Nursing, and colleagues wrote in the Journal of the American Geriatrics Society.

Davis and colleagues sought to examine which factors might explain why racial disparities exist in dementia diagnosis, and to discover any differences in the time to which disparities emerge after dementia onset.

The researchers conducted a retrospective cohort study utilizing survey data from the 1995 to 2016 Health and Retirement Study (HRS) linked with Medicare fee-for-service claims.

They identified 3,435 adults aged 65 years or older who experienced new onset of dementia via the Telephone Interview for Cognitive Status and proxy respondents. Date from dementia onset to diagnosis was determined by analyzing Medicare data up to 3years following onset using a list of established diagnosis codes. Non-Hispanic white and non-Hispanic Black respondents to the HRS with new onset of dementia from 1998 to 2013 were included in the sample.

Cox proportional hazards modeling was used to examine the association between an individual’s reported race and likelihood of diagnosis after accounting for sociodemographic characteristics, income, education, functional status and health care use.

Results showed that 30.1% of individuals received a diagnosis within 36 months of dementia onset. In unadjusted analyses, the difference in cumulative proportion diagnosed by race continued to increase across time following onset: 23.8% of non-Hispanic Black compared with 31.4% of non-Hispanic white patients were diagnosed within 36months of dementia onset (HR = 0.73; 95% CI, 0.61-0.88).

Researchers also found the association persisted after adjustment for functional status and health care use; however, these factors had less of an impact on the strength of the association than income and level of education.

“These finding suggest that race is influential in diagnosis likelihood because of structural and systemic factors,” Davis and colleagues wrote.