Telephone screening for amnestic mild cognitive impairment

Abstract

Objectives: To evaluate the utility of telephone screening for identifying subjects with amnestic mild cognitive impairment (aMCI) for enrollment in a clinical trial and to identify which elements of the modified Telephone Interview for Cognitive Status (TICS-m) best predicted the in-clinic determination of aMCI.

Methods: Subjects aged ≥65 years with memory complaints responded to an advertisement for a clinical trial by calling a central telephone recruiting agency. To determine eligibility, subjects went through a stepwise selection procedure involving a review of major protocol inclusion and exclusion criteria, followed by administration of the Category Fluency Test (CFT) and then the TICS-m. Subjects meeting entry criteria, who obtained a score of ≤13 on the CFT for “animals” and ≤24 on the CFT for “animals” and “fruits” and who scored between 19 and 38 on the TICS-m, were referred for a clinic appointment to determine whether they met clinical criteria for aMCI. Clinical criteria for aMCI required a score of ≥24 on the Mini-Mental State Examination and a score of ≤37 on the Rey Auditory Verbal Learning Test. A post hoc analysis was performed using factor analysis and logistic regression models to investigate which elements of the TICS-m best predicted the in-clinic determination of aMCI.

Results: Of 16,988 subjects who called the telephone agency, 8,742 passed the review of inclusion/exclusion criteria; 6,090 met the CFT cut scores and received the TICS-m; 5,223 met cut scores on the TICS-m and were referred for an in-clinic appointment; 747 were seen in the clinic; and 324 met clinical criteria for aMCI. Factor analysis indicated three factors on the TICS-m: language/attention, orientation, and memory. The memory factor, comprising immediate and delayed recall of a word list, was the most important contributor for identifying subjects who met clinical criteria for aMCI.

Conclusion: Only 2% of subjects who underwent telephone screening were recruited into the study, but 43% of those who passed telephone screening and were seen in the clinic met clinical criteria for aMCI. The word recall tests of the TICS-m were the most important items for identifying which subjects met clinical criteria for aMCI.