Reasons for the Early Identification of AD and MCI

Due to the development of multiple treatment medications since 1997, early identification of AD in primary care may reduce the rate of disease progression and delay placement in a nursing home. (See New Treatment Findings).

The earlier the treatment, the longer the delay of symptom progression from MCI and the less overall financial cost. (RS Doody et al Archives of Neurology, 58: 427-433, 2001)

Earlier* References:
Rogers, SL, Farlow, MR, Doody, RS et al. A 24-week double-blind, palcebo-controlled trial of donepezil in patients with Alzheimer's disease. Neurology, 50: 136-145, 1998.
Small, GW, Donohue, JA, Brooks, RL An economic evaluation of donepezil in the treatment of Alzheimer's disease. Clin Ther. 20: 838-850, 1998.

Many studies have focused upon treatment of those cognitive ability changes known as Mild Cognitive Impairment (MCI), which are most predictive of Alzheimer's. The CANS-MCI detects those changes in primary care facilities so that patients have a better chance of being responsive to early MCI treatment.

Impairments that are milder than AD are predictive of AD years before a diagnosis.

This became evident to many scientists around 1998:
Early* Reference: Duncan, BA & Siegel, AP Early diagnosis and management of Alzheimer's disease. Journal of Clinical Psychiatry, 59(suppl 9): 15-21, 1998. MCI

Mild and even moderate AD is underdiagnosed in primary care.

This became evident to many scientists around 1997: Early* References: Early Alzheimer's diagnosis can delay disease progression and hepl reduce costs, complications. Healthc Demand Dis Manag. 3:71-75, 1997. DR Gifford & JL Cummings Neurology, 52: 224-227, 1999. MCI

Family members often have inhibitions that keep them from bringing loved ones with dementia to a primary care physician. Sometimes people with dementia or MCI resist any effort to have their mental abilities evaluated. The result is that Mild Cognitive Impairment (MCI) and even AD is sometimes not diagnosed until long after the initial onset. Even physician recognition of early dementia symptoms in primary care is sometimes poor because they do not use validated methods for testing mental status. The distinction between Mild Cognitive Impairment (MCI or even early AD) and normal cognitive changes associated with aging can be difficult for primary care physicians to make unless they are trained to use psychometrics. Although there are not good data concerning avoidance by primary care physicians, we have heard a number of people say that their spouses were not examined for the possibility of AD and, instead, were told, "Oh, you're doing okay". In the absence of treatments that would reverse the dementia, many primary care physicians might not feel comfortable dealing with the issue. People with very high intelligence may also be able to compensate for (or just mask) the symptoms when examined by their primary care doctors. On the other hand, there are good data to indicate that spouses are excellent judges of the changes associated with Mild Cognitive Impairment (MCI) and the first signs of AD.

Early* References:
Ross, GW, Abbott, RD, Petrovich, H et al. Frequency and characteristics of silent dementia among elderly Japanese-American men. JAMA, 277: 800-815, 1997.

Callahan, CM, Hendrie, JC, Tierney, WM Documentation and evaluation of cognitive impairment in elderly primary care patients. Ann Intern Med., 122: 422-429, 1995. MCI

Jacobs, DM, Samo, M, Dooneief, G et al. Neuropsychological detection and characterization of preclinical Alzheimer's disese. Neurology, 45: 957-962, 1995. MCI

Not only does the delay in diagnosis miss an opportunity for treatment, but, because the disorder involves memory loss, the delay increases the chances of other problems, multiplying the demands placed upon caretakers. For example, people with cognitive impairments have trouble following prescribed treatment for their hypertension, infections, psychiatric problems, or diabetes unless helped.

Early* Reference:
American Psychiatric Association. Practice guideline for the treatment of patients with Alzheimer's disease and other dementias of late life. Am J Psychiatry, 154 (Suppl): 1-39, 1997.

If a way could be found to delay the onset of Alzheimer's disease for an average of just two years, between now and 2050, the number of affected individual would decline by 1.9 million. Researchers at Johns Hopkins used U.S. Census and mortality data to project the prevalence of Alzheimer's off into the future. In 1997, an estimated 2.3 million Americans had the disease, with about 360,000 new cases diagnosed each year. By 2050, the rate of Alzheimer's is expected to almost quadruple, with the disease afflicting some 8.6 million Americans, one person in 45, with 1.1 million diagnoses each year. But if the disease could be delayed even as briefly as for two years, through such interventions as statins, anti-inflammatory drugs, Aricept, Excelon, or other drugs, 1.9 million cases could be prevented by 2050, saving the country more than $10 billion in cost of care. The authors conclude that even without a major treatment breakthrough, small, incremental progress could make a real difference.

Reference:
American Journal of Public Health (1998) 88:1337 March 16, 1999

*Following the more recent work of early reference authors is often a useful way to stay abreast of the most up to date material on a specific topic.

Why is the diagnosis often delayed?