Misdiagnosis of Alzheimer's Disease Is Costly for Patients

The diagnosis and management of patients with dementing illnesses can be challenging, but the cost of misdiagnosing dementia as Alzheimer’s disease (AD) can be high, according to a study published in Alzheimer’s & Dementia.

AD is the most common cause of dementia, accounting for 60% to 80% of all dementias in the US, but it is not uncommon for patients with vascular dementia (VD) or Parkinson’s disease (PD) to be misdiagnosed with AD.

The investigators found that approximately 17% of VD patients were misdiagnosed initially with AD and 8% of PD patients had a history of AD misdiagnosis. And for half of the misdiagnosed patients, a correct diagnosis may not be confirmed for more than 1 year.

“The results of this study suggest substantial levels of AD misdiagnosis among Medicare beneficiaries who eventually receive a corrected diagnosis of either VD or PD,” the authors wrote.

They added that their findings suggest there are potential benefits from early and accurate diagnosis. However, they pointed out that the sensitivity of current clinical diagnostic criteria for AD ranges from 71% to 87% and specificity from as low as 44% to 71%. These numbers suggest substantial misdiagnosis rates among patients with dementia.

Excess medical costs for patients misdiagnosed with AD, who were later confirmed to have VD or PD increases annually for each year of misdiagnosis, peaking at approximately $9500 to $14,000 annually.

The researchers used claims data form the Standard Analytical Files for a 5% random sample of Medicare beneficiaries. They separated patients based on the history of AD diagnosis before confirmed VD/PD diagnosis and considered patients with no AD diagnosis before confirmed VD/PD diagnosis as comparators.

“The significant and potentially avoidable medical resource use and related costs associated with misdiagnosis of AD—and their dissipation after the correction of that diagnosis—suggest substantial value not only of ruling out AD but of doing so as early as possible,” the authors concluded.