Characteristics of a two-stage screen for incident dementia

• Published in: Journal of clinical epidemiology 2003-11, Vol.56 (11), p.1038-1045
• Main Authors: Hayden, Kathleen M, Khachaturian, Ara S, Tschanz, JoAnn T, Corcoran, Chris, Nortond, Maria, Breitner, John C.S, for the Cache County Study Group
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Algorithms; Biological and medical sciences; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Dementia; Dementia - diagnosis; Dementia - epidemiology; Dementia disorders; Education; Epidemiology; Estimates; Female; Humans; Incidence; Male; Mass screening; Mass Screening - methods; Medical imaging; Medical sciences; Neurology; Prevalence; Questionnaires; Receiver-operating characteristic analysis; Reproducibility of Results; ROC Curve; Sensitivity; Sensitivity and Specificity; Specificity; Studies; Surveys and Questionnaires; Utah - epidemiology; Validation sample
• ISSN: 0895-4356; 1878-5921
• DOI: 10.1016/S0895-4356(03)00247-6

To avoid costly evaluation of healthy individuals, efficient methods of screening for incident dementia must combine adequate sensitivity and high specificity. Two-stage screening may offer improvements over single-stage methods. We therefore investigated a two-stage screening protocol for incident dementia among 3,308 elderly. We administered the Modified Mini-Mental-State (3MS) or, rarely, Jorm's IQCODE, to a validation sample of 441 high-risk respondents. Informants then completed the Dementia Questionnaire (DQ). Finally, all 441 sample members underwent physical, neurologic, and neuropsychologic assessment. We studied the sensitivity and specificity of the 3MS/IQCODE and DQ using Receiver-Operating Characteristic analyses. A 3MS cut point of 82/83 (of 100) yielded sensitivity and specificity of 91.5 and 90.1%. With 3MS scores of ⩽82, a DQ cut point of 2/3 (of five) yielded conditional sensitivity and specificity of 90.2 and 55.3%. Combining these instruments yielded sensitivity and specificity of 82.5 and 95.6%. Age stratification and use of longitudinal decline score criteria did not materially improve these figures. The improved specificity of the two-stage approach offers economies that are attractive, particularly if sensitivity can be enhanced, for example, by examination of a high-risk validation sample.