Objective: To evaluate the psychometric characteristics of the Cognitive Difficulties Scale (CDS), a 39-item Likert-type self-report instrument that requires a fifth grade reading level. The CDS is a popular instrument that has been shown to predict cognitive decline in older persons.
Method: Participants were 512 consecutive outpatient referrals (71% women, mean age 60.6, and education 14.6 years) for a neuropsychological examination in a memory disorders clinic as part of a broader neurodiagnostic workup for cognitive decline. A principal components analysis was followed by a varimax rotation (Kaiser). Factor scores were investigated in relation to multiple internal and external criteria including demographics, Cronbach's alpha, Digit Span, and Wechsler Memory Scale-IV Logical Memory (LM) and Visual Reproduction (VR), and Minnesota Multiphasic Personality Inventory (MMPI)-2 measures of depression, anxiety, somatic preoccupations, and thought disturbance.
Results: Six dimensions of cognitive complaint emerged accounting for 64% of the variance: attention/concentration, praxis, prospective memory, speech problems, memory for people's names, and temporal orientation. The factors showed good internal consistency (alphas > .850). Correlations with Digit Span, LM, and VR were all nonsignificant. CDS scores were associated with MMPI-2 measures of anxiety, depression, somatic preoccupation, and thought disturbance. Percentiles and T-scores were derived for raw scores on the CDS and its six component subscales.
Conclusion: The CDS is a multidimensional measure of subjective cognitive complaints that provides clinicians with a psychometrically sound basis for deriving a profile with six subscale scores. The test has clinical utility and is a potentially useful tool in research involving age-related cognitive changes and meta-cognition.
Keywords: Dementia; Elderly/aging; Everyday function; Learning and memory; Meta-cognition; Mood (anxiety, depression).