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.