Researchers from the Indiana University School of Medicine, the Regenstrief Institute, Inc. and the Indiana University Center for Aging Research begin to answer this difficult question in a study published in the July issue of the Journal of General Internal Medicine, now available online.
The researchers conducted a dementia screening program on 3,340 older adults attending primary care clinics. They used the CSID, a highly regarded, culturally sensitive screening test. Screening results indicated that 434 were possibly or potentially suffering from dementia.
"Dementia is common and unrecognized in primary care," said Malaz Boustani, M.D., M.P.H., the first author of the study and an assistant professor of medicine. "Since screening instruments alone have insufficient specificity to establish a valid diagnosis of dementia, all 434 were invited back for a diagnostic assessment."
Unfortunately 50 percent of those in the study who screened positive for dementia did not return to evaluate their screening results. Such evaluation would have ruled-in or ruled-out the presence of dementia.
"That's similar to half of female patients whose mammograms show possible cancers not returning for biopsies to determine whether they have a malignancy. Screening tools require confirmation and the primary care doctor who screens must be prepared to follow up with confirmatory testing," said Dr. Boustani.
Of the 227 who did return for diagnostic assessment, only one-half received a diagnosis of dementia. Slightly less than one-third had mild cognitive impairment not severe enough to cause dementia. One-fifth did not have any type of cognitive problem.
Early diagnosis of dementia may allow individuals to plan for their future while they still have the mental capacity to make important care and end-of-life decisions. There are medications which may improve symptoms of dementia in some people.
The negative impact of unrecognized dementia on the management of other medical conditions is significant, noted Dr. Boustani. "Physicians typically are treating older adults for multiple chronic diseases such as hypertension, diabetes and high cholesterol and unless the patient presents with symptoms of dementia, the physician assumes the patient has the mental capacity to take medications appropriately and follow other directions. If we don't detect and help older adults with asymptomatic dementia, they potentially will not benefit from the medical management of their other health problems and thus, become big users of health-care dollars."
Additionally, dementia puts both the patient and others at risk. Individuals with advanced dementia are better off not living alone or driving.
The cost to society for care of individuals with unrecognized dementia is substantial. The cost of screening and, if indicated, diagnosing each older adult who participated in the study was $130. If the total cost of the program is divided by the number of cases of dementia detected during the study, each confirmed dementia case would cost $4,000.
The authors found the disparity between the number of patients screened and those that returned for diagnostic assessment disturbing.
"Our team thinks this may reflect the societal stigma of dementia," said Dr. Boustani. "Patients may be scared that they will be discriminated against in the workplace or that they will be placed in a nursing home against their will."
Co-authors of the study are Christopher Callahan, M.D.; Frederick Unverzagt, Ph.D.; Mary Guerriero Austrom, Ph.D.; Anthony Perkins, M.S.; Bridget Fultz, M.A.; Siu Hui, Ph.D.; and Hugh Hendrie, MB, ChB, DSc. The study was funded by a grant from the Agency for Healthcare Research and Quality.
The IU and Regenstrief researchers currently are conducting a collaborative study, the PRISM - US vs. UK, with British researchers from the University of Kent at Canterbury to learn whether such a stigma exists and, if so, its variation between the U.S. and the United Kingdom health-care systems.