The validation of a mailed health survey for screening of dementia of the Alzheimer's type.
OBJECTIVE
To test the efficacy of a mailed health survey, which included the Clock Completion Test (CCT), to screen previously undiagnosed older adults for dementia of the Alzheimer's type (DAT) in a community-dwelling population, and to determine whether the addition of selected risk factors for Alzheimer's disease (AD) would enhance the screening instrument's operating characteristics.


METHODS
Comparison of the results of a self-administered screen for DAT with the diagnosis of DAT by clinician evaluation or telephone interviews.


METHODS
A geriatric assessment clinic.


METHODS
Three hundred and five women age 65 and older from St. Louis, Missouri.


METHODS
The sensitivity and specificity of the CCT and the CCT plus risk factors for AD were evaluated using two standards: The Short Blessed Test (SBT) and the physician diagnosis of probable AD using National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria.


RESULTS
Sensitivity and specificity for the CCT by SBT criteria were 63% and 79%, respectively. Using the physician's assessment as a criterion, the CCT had better sensitivity (67%) but poorer specificity (69%). Adding two or more risk factors for AD improved sensitivity and specificity to 71% and 89% and, in the physician assessment subgroup, to 75% and 87%, primarily by halving the false-positive rate.


CONCLUSIONS
The combination of the simple, self-administered CCT and two or more AD risk factors is a more effective screening instrument for DAT and potentially preclinical DAT than the CCT alone. However, the instrument may be better suited for use in an office setting because of a poor response rate by subjects with dementia.
Ball
L J
LJ
Older Adult Health Center, Division of Geriatrics and Gerontology, Washington University School of Medicine, St. Louis, Missouri, USA.
Ogden
A
A
Mandi
D
D
Birge
S J
SJ
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology; D001827:Body Height; D015709:Correspondence as Topic; D004522:Educational Status; D015914:Estrogen Replacement Therapy / Q000706:statistics & numerical data; D005189:False Positive Reactions; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008403:Mass Screening / Q000379:methods* / Q000523:psychology / Q000592:standards; D008487:Medical History Taking / Q000592:standards; D008923:Missouri / Q000453:epidemiology; D009483:Neuropsychological Tests / Q000592:standards*; D009819:Office Visits; D010349:Patient Compliance / Q000523:psychology / Q000706:statistics & numerical data; D010808:Physical Examination / Q000592:standards; D011159:Population Surveillance / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016037:Single-Blind Method; D011795:Surveys and Questionnaires / Q000592:standards*