On the 21-item Alzheimer's Questionnaire, patients having trouble remembering the day, month, year, and time of day were almost 18 times more likely to have amnestic mild cognitive impairment, a precursor to dementia (OR 17.97, 95% CI 2.63 to 122.77, P=0.003), according to Michael Malek-Ahmadi, MSPH, and colleagues from the Banner Sun Health Research Institute in Sun City, Ariz.
Those who often repeated questions, statements, and stories on the same day also were at very high risk (OR 13.12, 95% CI 3.02 to 57.66, P=0.001), the researchers reported online in BMC Geriatrics.Distinguishing mild cognitive impairment, particularly when associated with memory loss rather than loss of other functional domains, can be clinically challenging and time consuming, and brief screening tools are sorely needed as the aging population expands, according to the researchers."Additionally, as new therapies for Alzheimer's disease transition from being symptomatic to disease-modifying, identifying individuals who are at risk or in the earliest stages of the disease will be crucial in determining and improving disease outcome," they wrote.
A pilot study by these researchers recently showed good sensitivity and specificity for the Alzheimer's Questionnaire, with responses about various aspects of memory and related cognitive concerns being provided by caregivers or other informants.
To see if certain components of the questionnaire were particularly accurate in pinpointing these types of impairments, Malek-Ahmadi's group compared responses among 47 patients who had been diagnosed with amnestic mild cognitive impairment and 51 controls who were participants in a program involving posthumous brain and body donation.
The diagnosis of cognitive impairment had been made clinically and with neuropsychological testing, with scores on verbal memory recall measures falling 1.5 standard deviations below normal ranges for age and educational attainment.
Cognitively normal participants all scored higher than 1.5 standard deviations on the neuropsychological tests.
A simple questionnaire can help differentiate individuals experiencing normal age-related memory loss from those at risk for developing dementia, most notably by their orientation to time and patterns of repetitive speech, researchers found.
The Alzheimer's Questionnaire assesses memory, language, orientation, visuospatial competence, and functional capacity by a series of yes/no questions such as, "Does the patient have trouble remembering to take medications?"
On almost all questions, significantly more "yes" responses were seen for the cognitive impairment group.
Regression analysis determined that, along with repetitive speech and disorientation as to time, two other questions were highly predictive.
One was whether the patient has trouble dealing with financial matters such as paying bills (OR 11.60, 95% CI 2.10 to 63.99, P=0.005), and the second was if the patient showed an impaired sense of direction (OR 5.84, 95% CI 1.09 to 32.30, P=0.04), according to the researchers.
Further analysis indicated that the coefficient of determination (R2) was 0.71, which meant that the four identified items could account for a substantial proportion of the variance between patients with amnestic mild cognitive impairment and those who were cognitively normal.
The researchers then calculated that the four items together had a sensitivity of 80.3% and a specificity of 81.8%, with the area under the curve being 0.94.
"These data indicate that problems with orientation to time, repeating statements and questions, difficulty managing finances, and trouble with visuospatial orientation may accompany memory deficits in amnestic mild cognitive impairment," the researchers stated.
Limitations of the study included the wide confidence intervals for the four items' odds ratios and the possibility of bias in the R2 approximation.
In addition, the study sample was ethnically homogeneous.
Primary source: BMC Geriatrics
By Nancy Walsh for MedPage Today
No comments:
Post a Comment