Subjective cognitive impairment (SCI), which is when someone self-reports on their cognitive symptoms, can be useful in dementia surveillance and helping researchers evaluate trends in dementia. A new study finds it’s a valid way to keep tabs on who may get dementia compared to established dementia measures.
It’s tough to develop a robust dementia surveillance system, like the national registry for cancer surveillance, for a number of reasons. There aren’t a lot of cost-effective biomarkers to spot it, there’s no routine dementia assessment and there are biases in some of the data used.
People often use SCI because it’s part of diagnosing mild cognitive impairment (MCI), which is an early sign of dementia. But not all SCI is indicative of dementia, the authors pointed out.
Researchers assessed the relationship between SCI and a validated probable dementia algorithm in 1,936 people who are part of the 2012 National Health and Aging Trends Study (NHATS). The report was published in Alzheimer’s & Dementia on March 1.
The data showed that SCI was prevalent in 12.2% of the people compared to 8.4% of them with probable dementia. In other words SCI prevalence was nearly 1.5 times that for probable dementia. SCI sensitivity was 63.4% and specificity was 92.5% against dementia were comparable with similar metrics for the probable dementia measure when compared to the Aging, Demographics, and Memory Study–based dementia criteria (the gold standard in diagnosis). Overall, the agreement between SCI and the validated measure of dementia was 90%.
“This study fills this critical gap in knowledge by assessing and interpreting the performance of SCI against a validated measure of probable dementia,” the authors wrote. The team said the study gives clinicians a reference standard to assess the validity of using SCI to detect dementia risk in the population.
The findings were consistent with other studies showing that SCI and probable dementia measures were highest among older age groups, Blacks and Hispanics, and people with lower educational attainment. Unlike other studies, the team didn’t find differences in sex between the measures.
