Affiliations: [a]
School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| [b]
Department of Family Medicine and Rush Alzheimer’s Disease Center; Rush University Medical Center, Chicago, IL, USA
| [c]
Berman Center for Outcomes and Clinical Research, Minneapolis Medical Research Foundation, Hennepin Healthcare Research Institute, Minneapolis, MN, USA
| [d]
Department of Medicine, Division of Geriatrics, Hennepin County Medical Center and University of Minnesota, Minneapolis, MN, USA
Correspondence:
[*]
Correspondence to: Katherine L. Webb, Monash University, School of Public Health and Preventive Medicine, Address: 553 St Kilda Rd, Melbourne VIC 3004, Australia. Tel.: +61 03 9903 0555; E-mail: katherine.webb@monash.edu.
Abstract: Background:Cognitive test-retest reliability measures can be used to evaluate meaningful changes in scores. Objective:This analysis aimed to develop a comprehensive set of test-retest reliability values and minimal detectable change (MDC) values for a cognitive battery for community-dwelling older individuals in Australia and the U.S., for use in clinical practice. Methods:Cognitive scores collected at baseline and year 1, in the ASPirin in Reducing Events in the Elderly clinical trial were used to calculate intraclass correlation coefficients (ICC) for four tests: Modified Mini-Mental State examination (3MS), Hopkins Verbal Learning Test-Revised (HVLT-R), single-letter Controlled Oral Word Association Test (COWAT-F), and Symbol Digit Modalities Test (SDMT). 16,956 participants aged 70 years and over (65 years and over for U.S. minorities) were included. ICCs were used to calculate MDC values for eight education and ethno-racial subgroups. Results:All four cognitive tests had moderate (ICC > 0.5) to good (ICC > 0.7) test-retest reliability. ICCs ranged from 0.53 to 0.63 (3MS), 0.68 to 0.77 (SDMT), 0.56 to 0.64 (COWAT-F), 0.57 to 0.69 (HVLT-R total recall), and 0.57 to 0.70 (HVLT-R delayed recall) across the subgroups. MDC values ranged from 6.60 to 9.95 (3MS), 12.42 to 15.61 (SDMT), 6.34 to 8.34 (COWAT-F), 8.13 to 10.85 (HVLT-R total recall), and 4.00 to 5.62 (HVLT-R delayed recall). Conclusion:This large cohort of older individuals provides test-retest reliability and MDC values for four widely employed tests of cognitive function. These results can aid interpretation of cognitive scores and decline instead of relying on cross-sectional normative data alone.
Keywords: Controlled oral word association test, hopkins verbal learning test-revised, minimal detectable change, modified mini-mental state examination, symbol digit modalities test, test-retest reliability
