Open AccessDevelopment of a subjective cognitive decline questionnaire using item response theory: A pilot study
Author(s) -
Gifford Katherine A.,
Liu Dandan,
Romano Raymond R.,
Jones Richard N.,
Jefferson Angela L.
Publication year - 2015
Publication title -
alzheimer's and dementia: diagnosis, assessment and disease monitoring
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.497
H-Index - 37
ISSN - 2352-8729
DOI - 10.1016/j.dadm.2015.09.004
Subject(s) - item response theory , computerized adaptive testing , trait , psychology , cognition , clinical psychology , classical test theory , test (biology) , test theory , psychometrics , psychiatry , paleontology , computer science , biology , programming language
Subjective cognitive decline (SCD) may indicate unhealthy cognitive changes, but no standardized SCD measurement exists. This pilot study aimed to identify reliable SCD questions. Methods A total of 112 cognitively normal (NC; 76 ± 8 years; 63% female), 43 mild cognitive impairment (MCI; 77 ± 7 years; 51% female), and 33 diagnostically ambiguous participants (79 ± 9 years; 58% female) were recruited from a research registry and completed 57 self‐report SCD questions. Psychometric methods were used for item reduction. Results Factor analytic models assessed unidimensionality of the latent trait (SCD); 19 items were removed with extreme response distribution or trait‐fit. Item response theory (IRT) provided information about question utility; 17 items with low information were dropped. Post hoc simulation using computerized adaptive test (CAT) modeling selected the most commonly used items (n = 9 of 21 items) that represented the latent trait well ( r = 0.94) and differentiated NC from MCI participants ( F [1, 146] = 8.9, P = .003). Discussion IRT and CAT modeling identified nine reliable SCD items. This pilot study is a first step toward refining SCD assessment in older adults. Replication of these findings and validation with Alzheimer's disease biomarkers will be an important next step for the creation of a SCD screener.