Estimation of diagnostic performance of dementia screening tests: Mini-Mental State Examination, Mini-Cog, Clock Drawing test and Ascertain Dementia 8 questionnaire.

OBJECTIVE: Dementia is one of the leading causes of dependence in the elderly. This study was conducted to estimate diagnostic performance of dementia screening tests including Mini-Mental State Examination (MMSE), Mini-Cog, Clock Drawing Test (CDT) and Ascertain Dementia 8 questionnaire (AD8) by Bayesian models.

METHOD: A total of 2015 participants aged 65 years or more in eastern China were enrolled. The four screening tests were administered and scored by specifically trained psychiatrists. The prior information of sensitivity and specificity of every screening test was updated via Bayes' theorem to a posterior distribution. Then the results were compared with the estimation based on National Institute of Aging-Alzheimer's Association criteria (NIA-AA).

RESULTS: The diagnostic characteristics of Mini-Cog, including sensitivity, specificity, PPV, NPV, especially the Youden index, performed well, even better than the combinations of several screening tests.

CONCLUSION: The Mini-Cog with excellent screening characteristics, spending less time, could be considered to be used as a screening test to help to screen patients with cognitive impairment or dementia early. And Bayesian method was shown to be a suitable tool for evaluating dementia screening tests.

CONCLUSION: The Mini-Cog with excellent screening characteristics, spending less time, could be considered to be used as a screening test to help to screen patients with cognitive impairment or dementia early. And Bayesian method was shown to be a suitable tool for evaluating dementia screening tests.