Item response theory reveals variability of functional impairment within clinical dementia rating scale stages.
OBJECTIVE
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.


CONCLUSIONS
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.
Texas A&M University, College Station, TX 77843, USA.
Tyler M
TM
Miller
Steve
S
Balsis
Deborah A
DA
Lowe
Jared F
JF
Benge
Rachelle S
RS
Doody
D000203:Activities of Daily Living / Q000145:classification* / Q000523:psychology*; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000145:classification* / Q000175:diagnosis*; D005260:Female; D006686:Hobbies; D006801:Humans; D007406:Interview, Psychological; D007600:Judgment; D008297:Male; D008875:Middle Aged; D009949:Orientation; D011340:Problem Solving; D011594:Psychometrics; D012917:Social Adjustment