Identifying prospective memory deficits in multiple sclerosis: Preliminary evaluation of the criterion and ecological validity of a single item version of the memory for intentions test (MIST)

Abstract

Objectives: Difficulties with prospective memory (PM) are not routinely assessed in persons with multiple sclerosis (MS) even though they can impact daily functioning. This study aimed to examine the preliminary criterion and ecological validity of a highly abbreviated Memory for Intentions Test (MIST) intended to serve as an initial screening of PM in persons with MS. Methods: Participants (n = 112) were classified as impaired if they performed 1.5 standard deviations below the normative mean on the MIST. Individual MIST trials with adequate difficulty and discriminability were examined using receiver operating characteristic analyses, with their classification accuracies, sensitivities, and specificities compared to each other. Regressions were run to evaluate their ecological validity, with appointment attendance and employment as the outcomes. Results: Two trials had a classification accuracy of ≥80%: Trial 3 (79% sensitivity, 84% specificity) and Trial 4 (57% sensitivity, 91% specificity). These two trials had comparable specificity (p=.127), with Trial 3 having slightly higher sensitivity (p=.083). Only Trial 4 was significantly associated with appointment attendance (b = 1.63, p=.047) and unemployment (aOR = 11.20, p=.027). Discussion:Trial 4 of the MIST, a verbal task with a time-based cue that requires participants to complete a pre-specified response after a 15-minute delay, has the potential to be a screener for PM.

Keywords:

• Multiple sclerosis
• prospective memory
• cognitive screening
• functional outcomes
• Memory for Intentions Test
• appointment attendance

Acknowledgements

Results from this work were presented at the Consortium of Multiple Sclerosis Centers (CMSC) annual meeting in Orlando, FL in October 2021.

The parent study was supported by a pilot grant from the National Multiple Sclerosis Society (grant number PP-1901-33103). Dr. Gromisch is also a Harry Weaver Scholar of the National Multiple Sclerosis Society. The funding source was not involved in the study design, collection, analysis, or interpretation of the data or writing and submission of the article.

The views and opinions expressed in this article reflect those of the authors and do not necessarily reflect those of the United States Department of Veterans Affairs.

The Patient Determined Disease Steps (PDDS) is provided for use by the North American Research Committee on Multiple Sclerosis (NARCOMS) Registry (www.narcoms.org/pdds). NARCOMS is supported in part by the CMSC and CMSC Foundation.

Declaration of interest

Dr. Raskin is the developer of the MIST. The authors have no other competing interests to declare.

Disclosure statement

No potential conflict of interest was reported by the authors.