Validity of Memory for Intentions Screening Test for Prospective Memory in Multiple Sclerosis

The Trial 4 Memory for Intentions Test (MIST) verbal task can detect prospective memory deficits in patients with multiple sclerosis (MS), according to a study presented at the 2021 Annual Meeting of the Consortium of Multiple Sclerosis Centers (CMSC) held October 25-28, 2021 in Orlando, Florida.

Prospective memory is not typically assessed in patients with MS, who often report challenges in this area impact them frequently. The MIST evaluates prospective memory through 8 tasks whose characteristics are distinguished by cue type (time or event), time delay (2 minutes or 15 minutes), and response type (action or verbal). The objective of the current study was to identify which of 8 MIST tasks could best detect prospective memory deficits among patients with MS.

Researchers assessed the prospective memory of 112 patients with MS using the MIST. Individuals who performed at or below the 1^st percentile were classified as impaired. They then utilized item response theory (IRT) analysis with R package Multidimensional Item Response Theory (MIRT) to define tasks’ difficulty and discriminability. Of 5 tasks with adequate difficulty and discriminability, Trial 3 (100% sensitivity) and Trial 4 (86% sensitivity) tasks had the best classification accuracies. They had comparable sensitivity (P =.317). Trial 4 had statistically significantly higher specificity (90%) than Trial 3 (81% P =.061). Trial 3 involves an action-based cue and 2-minute delay, and Trial 4 involves an event-based cue and 15-minute delay.

The researchers acknowledged that Trial 3’s sensitivity may be attributed to influence by preceding cognitive load.

Trial 4 has “the optimal balance” of sensitivity and specificity for identifying prospective memory deficits in patients with MS, according to the researchers.

“The next steps will be to evaluate trial 4’s utility as part of the aMACFIMS [Minimal Assessment of Cognitive Function in MS] in terms of screening and monitoring PM deficits of PwMS [persons with multiple sclerosis],” they concluded.

Reference

Gromisch ES, Turner AP, Neto LO, et al. Identifying prospective memory deficits in multiple sclerosis with a single task from the memory for intentions test: an item response theory and receiver operating characteristic analysis. Presented at: CMSC 2021; October 25-28, 2021; Orlando, Florida. Abstract NNN01.