To Change is Human: "Abnormal" Reliable Change Memory Scores are Common in Healthy Adults and Older Adults.
OBJECTIVE
The rate at which people obtain reliably improved or declined cognitive test scores when retested, in the absence of a change in clinical condition, is largely unknown. The purpose of this study was to illustrate the prevalence of statistically reliable change scores on memory test batteries in healthy adults and older adults.


METHODS
Participants included three adult and older adult test-retest samples from memory test batteries. Reliable change scores (reliable change index with 90% confidence interval and practice effects) were calculated for the indexes and subtests of each battery. Multivariate analyses involved calculating the frequencies of healthy people obtaining one or more reliably declined or one or more reliably improved scores when considering all change scores simultaneously within each battery.


RESULTS
Across all batteries, having one or more reliably changed index or subtest score on retest was common. With most batteries, having two or more reliably changed scores was uncommon. Those with higher intellectual abilities were more likely to have a change on retest; however, no significant differences in base rates were found based on education level, sex, or ethnic minority status. Those older adults who did not have any low memory scores were more likely to improve than decline on retest.


CONCLUSIONS
Having a single reliably changed score on retest is common when interpreting a battery of memory measures. This has implications for determining cognitive decline and cognitive recovery, suggesting that multivariate interpretation is necessary.
Neurosciences Program (Brain Injury and Rehabilitation), Alberta Children's Hospital, Calgary, Alberta, Canada.|Departments of Paediatrics, Clinical Neurosciences, and Psychology, University of Calgary, Calgary, Alberta, Canada.|Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada.
Brian L
BL
Brooks
Pearson Clinical Assessment, San Antonio, TX, USA.
James A
JA
Holdnack
Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA, USA.|Spaulding Rehabilitation Hospital, Boston, MA, USA.|MassGeneral Hospital for Children Sport Concussion Program, Boston, MA, USA.|Home Base, A Red Sox Foundation and Massachusetts General Hospital Program, Boston, MA, USA.
Grant L
GL
Iverson
Cognition; Mild cognitive impairment; Multivariate; Psychometrics; Reliable change index; Test-retest
J Int Neuropsychol Soc. 2007 May;13(3):490-500
17445298
Arch Clin Neuropsychol. 2006 Jan;21(1):83-9
16169705
J Clin Exp Neuropsychol. 1999 Feb;21(1):70-86
10421003
J Gerontol B Psychol Sci Soc Sci. 1999 Mar;54(2):P116-24
10097774
Arch Clin Neuropsychol. 2010 Feb;25(1):14-21
20015965
Br J Clin Psychol. 2010 Jun;49(Pt 2):235-58
19646334
Arch Neurol. 2011 Jun;68(6):761-7
21670400
J Int Neuropsychol Soc. 1996 Nov;2(6):556-64
9375160
J Int Neuropsychol Soc. 1999 May;5(4):357-69
10349298
Arch Clin Neuropsychol. 2009 Nov;24(7):647-57
19749192
Mov Disord. 2012 Mar;27(3):349-56
22275317
Clin Neuropsychol. 2003 Nov;17(4):460-7
15168911
Am J Geriatr Psychiatry. 2010 Aug;18(8):684-91
21399729
J Consult Clin Psychol. 1991 Feb;59(1):12-9
2002127
Appl Neuropsychol Adult. 2012;19(1):61-70
22385381
J Int Neuropsychol Soc. 2008 May;14(3):463-78
18419845
J Int Neuropsychol Soc. 2001 Jul;7(5):597-605
11459111
Br J Clin Psychol. 2008 Jun;47(Pt 2):215-37
18039431
Assessment. 2011 Jun;18(2):156-67
20947705
Int Rev Neurobiol. 2009;84:81-103
19501714
Arch Clin Neuropsychol. 2001 Jan;16(1):75-91
14590193
Int J Geriatr Psychiatry. 1998 Oct;13(10):661-6
9818300
Am J Geriatr Psychiatry. 2009 May;17(5):368-75
19390294
Arch Clin Neuropsychol. 2001 Feb;16(2):183-91
14590186
J Int Neuropsychol Soc. 2001 Sep;7(6):693-702
11575591