Background/Aims: To investigate whether an item response theory (IRT) approach to measuring variations of dementia severity within Clinical Dementia Rating (CDR) stages is associated with activities of daily living (ADLs). Methods: IRT estimates of dementia severity within CDR stages in 1,181 patients were correlated with ADLs and analyzed. Results: IRT-determined dementia severity was significantly correlated with ADLs in three of four impaired dementia stages. Conclusion: An IRT approach shows considerable advantages over traditional scoring practices of the CDR not only because it increases precision in dementia measurement, but also because it enables one to discover more precise associations with functional outcomes such as ADLs.

Keywords:
Alzheimer’s disease, Clinical Dementia Rating scale, Item response theory
1.
Hughes CP, Berg L, Danziger WL, Coben LA, Martin RL: A new clinical scale for the staging of dementia. Br J Psychiatry 1982;140:566–572.
2.
Morris JC: The Clinical Dementia Rating Scale (CDR): current version and scoring rules. Neurology 1993;43:2412–2414.
3.
Chang YL, Bondi MW, McEvoy LK, Fennema-Notestine C, Salmon DP, Galasko D, Hagler DJ, Dale AM: Global clinical dementia rating of 0.5 in MCI masks variability related to level of function. Neurology 2011;76:652–659.
4.
Balsis S, Miller TM, Benge JB, Doody RS: Dementia staging across three different methods. Dement Geriatr Cogn Disord 2011;31:328–333.
5.
Lynch CA, Walsh C, Blanco A, Moran M, Coen RF, Walsh JB, Lawlor BA: The Clinical Dementia Rating sum of box score in mild dementia. Dement Geriatr Cogn Disord 2006;21:40–43.
6.
Musicco M, Salamone G, Caltagirone C, Cravello L, Fadda L, Lupo F, Mosti S, Perri R, Palmer K: Neuropsychological predictors of rapidly progressing patients with Alzheimer’s disease. Dement Geriatr Cogn Disord 2010;30:219–228.
7.
Lechowski L, Van Pradelles S, Le Crane M, d’Arailh L, Tortrat D, Teillet L, Vellas B, The REAL Group: Patterns of loss of basic activities of daily living in Alzheimer patients: a cross-sectional study of the French REAL cohort. Dement Geriatr Cogn Disord 2009;29:46–54.
8.
Lawton MP, Brody EM:Assessment of older people: self-maintaining and instrumental activities of daily living. Gerontologist 1969;9:179–186.
9.
Doody RS, Pavlik V, Massman P, et al: Changing patient characteristics and survival experience in an Alzheimer’s disease center patient cohort. Dement Geriatr Cogn Disord 2005;20:198–208.
10.
Hambleton RK, Swaminathan H, Jane Rogers H: Fundamentals of Item Response Theory. Newbury Park, Sage Publications, 1991.
11.
Benge JF, Balsis S, Geraci L, Massman PJ, Doody RS: How well do the ADAS-cog and its subscales measure cognitive dysfunction in Alzheimer’s disease? Dement Geriatr Cogn Disord 2009;28:63–69.
12.
Thissen D: Multilog User’s Guide, version 6.3. Scientific Software, 1991.
13.
Thissen D, Nelson L, Rosa K, McLeod LD: Item response theory for items scored in more than two categories; in Thissen D, Wainer D (eds): Test Scoring. London, Erlbaum, 2001, pp 141–186.
14.
Peterson RC, Smith GE, Waring SC, Ivnik RJ, Tangalos EG, Kokmen E: Mild cognitive impairment: clinical characterization and outcome. Arch Neurol 1999;56:303–308.
© 2012 S. Karger AG, Basel
2012
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