Racial disparities and temporal trends in dementia misdiagnosis risk in the United States

Abstract

Introduction: Systematic disparities in misdiagnosis of dementia across racial/ethnic groups have implications for health disparities. We compared the risk of dementia under- and overdiagnosis in clinical settings across racial/ethnic groups from 2000 to 2010.

Methods: We linked fee-for-service Medicare claims to participants aged ≥70 from the nationally representative Health and Retirement Study. We classified dementia status using an algorithm with similar sensitivity and specificity across racial/ethnic groups and assigned clinical dementia diagnosis status using ICD-9-CM codes from Medicare claims. Multinomial logit models were used to estimate relative risks of clinical under- and overdiagnosis between groups and over time.

Results: Non-Hispanic blacks had roughly double the risk of underdiagnosis as non-Hispanic whites. While primary analyses suggested a shrinking disparity over time, this was not robust to sensitivity analyses or adjustment for covariates. Risk of overdiagnosis increased over time in both groups.

Discussion: Our results suggest that efforts to reduce racial disparities in underdiagnosis are warranted.

Keywords: Alzheimer's disease; Clinical diagnosis; Dementia; Disparities; Health and retirement study.

Fig. 1

Weighted distributions of concordant and discordant* dementia classification across algorithmic and Medicare-based dementia ascertainment in non-Hispanic black and white Health and Retirement Study participants with Medicare FFS, 2000–2010. * Underdiagnosed is defined as having an algorithmic dementia diagnosis but no Medicare-claim-based dementia diagnosis, while overdiagnosed is defined as having a Medicare-claim-based dementia diagnosis but no algorithmic diagnosis. Persons with concordant Medicare and algorithmic dementia status are considered correctly diagnosed. Abbreviations: FFS, fee for service; NHW, non-Hispanic white; NHB, non-Hispanic black.

Fig. 2

Unadjusted and adjusted relative risk of misdiagnosis comparing non-Hispanic black to non-Hispanic white participants in Health and Retirement Study participants with Medicare FFS, 2000–2010*. * Relative risk at each year are estimated from regression models stratified by wave. The slope of the temporal trends in relative risk across years are estimated from the race × time interaction term in unstratified regression models.