The questionnaire provides a way to reach out to persons with dementia whose impairment otherwise may go undetected until substantial cognitive deterioration has occurred. A paper describing the questionnaire and its development was published in the August 2003 issue of the Journal of Clinical Outcomes Management.
The urgent need for the health care community to do a better job of recognizing patients with dementia has never been more clear. An estimated 4.5 million persons in the United States have Alzheimer's disease (AD), and this figure is expected to triple over the next 50 years. The challenge is compounded by the fact that most persons who are experiencing early symptoms of AD typically are not diagnosed, delaying interventions that could have a positive impact on patient outcomes.
"AD exacts a tremendous toll on individuals and society, including large excess economic costs in Medicare managed care plans" says Dr. Howard Fillit at the Institute for the Study of Aging in New York, who led the group of researchers. "Recent studies have demonstrated the effectiveness of disease management in preventing hospitalizations for AD in community-dwelling individuals. Early identification is the key to cost-effective care management for persons with dementia."
The questionnaire consists of a test of delayed recall and 2 questions that ask whether the person needs help with remembering to take medications or with planning a trip for errands. To develop the questionnaire, the researchers administered an 11-item questionnaire by phone to 60 cognitively impaired persons (age range, 57--99 years) and 44 elderly persons with intact cognitive function (age range, 56-100 years). They then used statistical analysis to select a combination of items that best distinguished which persons had cognitive impairment.
When the questionnaire is used in a population where 1 in 10 persons have dementia, its positive predictive value is 0.42. This means that of 100 persons who have a positive result on the screen, 42 will actually have cognitive impairment. This value compares favorably with other common screening tests, such as fecal occult blood testing for colon cancer, which produces 2.2 to 5.6 true positives out of 100 patients with positive results. A positive result on the screen does not equal a diagnosis of dementia but rather provides evidence that further diagnostic evaluation is needed.
The researchers designed the questionnaire to be administered to new enrollees in Medicare managed care plans. Several features make the questionnaire particularly attractive as a screening tool. It is brief, requiring only a few minutes to complete, and it is designed to be administered over the phone by a nonclinical interviewer. In addition, an integer-based scoring system allows for easy scoring and interpretation of results within moments of completion.
Although the initial reliability and validation study published in JCOM showed promising results, further validation studies involving a more extensive population are needed to confirm those results. Such a study is currently underway.