Validation of the telephone interview for cognitive status-modified in subjects with normal cognition, mild cognitive impairment, or dementia.

BACKGROUND The telephone assessment of cognitive functions may reduce the cost and burden of epidemiological studies. METHODS We validated the Telephone Interview for Cognitive Status-modified (TICS-m) using an extensive in-person assessment as the standard for comparison. Clinical diagnoses of normal cognition, mild cognitive impairment (MCI), or dementia were established by consensus of physician, nurse, and neuropsychological assessments. RESULTS The extensive in-person assessment classified 83 persons with normal cognition, 42 persons with MCI, and 42 persons with dementia. There was considerable overlap in TICS-m scores among the three groups. Receiver operating characteristic curves identified < or = 31 as the optimal cutoff score to separate subjects with MCI from subjects with normal cognition (sensitivity = 71.4%; subjects with dementia excluded), and < or = 27 to separate subjects with dementia from subjects with MCI (sensitivity = 69.0%; subjects with normal cognition excluded). The TICS-m performed well when subjects with MCI were pooled either with subjects with dementia (sensitivity = 83.3%) or with subjects with normal cognition (sensitivity = 83.3%). CONCLUSIONS Although the TICS-m performed well when using a dichotomous classification of cognitive status, it performed only fairly in separating MCI from either normal cognition or dementia. The TICS-m should not be used as a free-standing tool to identify subjects with MCI, and it should be used with caution as a tool to detect dementia.