Detection of memory impairment in the general population: screening by questionnaire and telephone compared to subsequent face-to-face assessment

BACKGROUND: Development of efficient methods for identifying subjects with Mild Cognitive Impairment (MCI) from the general population is warranted, because these subjects represent an important group for (epidemiological) research purposes.

OBJECTIVES: (1) To describe a two-step population screening for identifying adults with MCI from the general population for research purposes, by questionnaire and telephone; (2) to compare screening by telephone (method 1) to a subsequent face-to-face assessment (method 2).

METHODS: In method 1, subjects with memory complaints were identified from the general population (n = 5491) by a postal questionnaire. Subsequently, cognitive status and memory were assessed in a telephone interview using the Telephone Interview for Cognitive Status and the Ten Word Learning Test. Next, subjects with MCI according to method 1 were subjected to a face-to-face assessment for method 2, in which cognitive status and memory were assessed using the Mini Mental State Examination (MMSE) and the Auditory Verbal Learning Test (AVLT).

RESULTS: Two hundred and twenty-seven subjects completed both the telephone interview and the face-to-face assessment. Ninety-three subjects (41%) had MCI according to both methods. Seven subjects (3%) failed to meet MCI criteria according to method two because of an MMSE score <24; 127 subjects (56%) failed because of normal AVLT scores.

CONCLUSION: (1) The two-step population screening was able to detect a considerable number of MCI-subjects in the general population; (2) agreement between both methods was moderate. Therefore, the method of recruiting subjects for (epidemiological) studies has to be taken into consideration when interpreting results of these studies.