The time and change test: a simple screening test for dementia.
BACKGROUND: Although dementia screening tests are available, they have not gained widespread use in hospital or primary care settings. Our goal was to develop a simple, standardized, performance-based test incorporating real-world activities to augment screening efforts in older populations: the Time and Change (T&C) Test. METHODS: The study followed a prospective cohort design, involving medicine and surgery services at an urban teaching hospital. From consecutive admissions, 776 participants aged 70-98 years, 14% with dementia, were enrolled. T&C ratings were validated against a reference standard based on the modified Blessed Dementia Rating Scale and the Mini-Mental State Examination (MMSE). Convergent validity with other cognitive measures, test-retest agreement, and interobserver reliability were assessed. RESULTS: The T&C Test had a sensitivity of 86%, specificity of 71%, and negative predictive value of 97%. The T&C Test demonstrated convergent agreement with three cognitive measures, agreeing most strongly with the MMSE (r = .58). Test-retest and interobserver agreement rates were 88% and 78%, respectively. Education explained 3% of the variance of the T&C Test, compared with 13% of the MMSE. The T&C Test took a mean of 22.9 seconds to complete and was acceptable to participants. Refusal of any test component occurred in 39 individuals (5%). CONCLUSIONS: The T&C Test is a simple, accurate, reliable, performance-based tool for detection of dementia. With its quick, easy-to-use, real-world nature, we hope the T&C Test will be used for widespread cognitive screening in older populations.