Short term stability of verbal memory impairment in mild cognitive impairment and Alzheimer's disease measured using the International Shopping List Test

Abstract

There is a need for culture neutral neuropsychological instruments. The International Shopping List Test (ISLT) is sensitive to memory impairment in Alzheimer's disease (AD) in different cultural groups, although its sensitivity to mild cognitive impairment (MCI) and ability to be given repeatedly at short retest intervals is unknown. Performance on the ISLT was compared between groups of healthy adults, MCI, and AD from the Australian Imaging Biomarkers and Lifestyle study of ageing. Subjects were assessed four times in three months. In each group, the ISLT performance measures had high test–retest reliability, and group means remained stable over time. There was no difference between groups on within-subject variability. These data suggest that in English-speaking samples, the ISLT is sensitive to MCI and can be given repeatedly in order to assess change in memory.

Keywords:

• Verbal list learning
• International Shopping List Test
• Australian Imaging Biomarkers and Lifestyle
• Stability
• Test–retest reliability

Notes

Paul Maruff is a full-time employee of CogState Ltd., the company that provided the International Shopping List Test. Funding for the study was provided in part by the study partners: Australian Commonwealth Scientific Industrial and research Organization (CSIRO), Edith Cowan University (ECU), Mental Health Research institute (MHRI), Alzheimer's Australia (AA), National Ageing Research Institute (NARI), Austin Health, CogState Ltd., Hollywood Private Hospital, Sir Charles Gardner Hospital, AstraZeneca. The Australian Imaging Biomarkers and Lifestyle (AIBL) investigators thank Richard Head of CSIRO for initiating and facilitating the AIBL collaboration. The study also received support from the National Health and Medical Research Council (NHMRC), the Dementia Collaborative Research Centres program (DCRC2), and the Science and Industry Endowment Fund (SIEF). Alzheimer's Australia (Victoria and Western Australia) assisted with promotion of the study and the screening of telephone calls from volunteers. The AIBL team wishes to thank the clinicians who referred patients with Alzheimer's disease to the study: Brian Chambers, Edmond Chiu, Roger Clarnette, Mary Davison, John Drago, Peter Drysdale, Jacqueline Gilbert, Kwang Lim, Nicola Lautenschlager, Dina LoGiudice, Peter McCardle, Steve McFarlane, Alastair Mander, John Merory, Daniel O'Connor, Christopher Rowe, Ron Scholes, Mathew Samuel, Darshan Trivedi, David Darby, and Michael Woodward. We thank all those who participated in the study for their commitment and dedication to helping advance research into the early detection and causation of Alzheimer's disease.