Structural Brain Imaging for Newly Diagnosed Cognitive Impairment by Medicare Coverage Type

Structural brain imaging is guideline-recommended for cases with newly diagnosed cognitive impairment. Adherence to this recommendation and differences by Medicare coverage type are not known. We determined the structural imaging rate overall and by Medicare coverage type: traditional Medicare, Medicare Advantage, and dual eligibility for Medicare and Medicaid ("duals") and diagnosis of mild cognitive impairment (MCI) and dementia.

In this cross-sectional study, we used the 100% data for traditional Medicare and Medicare Advantage from 2020 through 2022. A total of 1,095,947 community-dwelling Medicare beneficiaries aged 65 to 84 were newly diagnosed with cognitive impairment in 2021, 373,561 (34.1%) with MCI and 722,386 (65.9%) with dementia. We determined receipt of structural imaging with MRI or CT scan within 365 days before or after the diagnosis.

Overall imaging rates within 365 days of diagnosis were 56.6% overall and 65.9% and 50.5% for an initial diagnosis of dementia and MCI, respectively. Rates were higher for nonduals than duals in traditional Medicare (60.5% versus 57.9%) and members of Medicare Advantage Plans (54.35 versus 52.7%). The initial scan was performed with an MRI in 29.3% of cases with lower rates in duals and Medicare Advantage.

In the 2021 full Medicare population with a new diagnosis of cognitive impairment, structural brain imaging was substantially underused. This gap in appropriate care was accentuated in Medicare Advantage Plan members and the socioeconomically disadvantaged duals. Sustained efforts are needed to ensure equitable adherence to this guideline-recommended procedure.

This observational study of the full Medicare population shows that structural brain imaging after diagnosis of cognitive impairment is underused, with lower rates in Medicare Advantage and for duals.