The Chinese Mini-Mental Status Test (CMMS) consists of 114 items intended to identify people with Alzheimer’s disease and senile dementia among people in China. An extensive clinical evaluation of this instrument was performed, whereby participants were interviewed by psychiatrists and nurses and a definitive diagnosis of dementia was made. Table 3.12 shows the results obtained for the subgroup of people with at least some formal education. Suppose a cutoff value of ≤ 20 on the test is used to identify people with dementia.
(a) What is the sensitivity of the test?
(b) What is the specificity of the test?