Short IQCODE as a screening tool for MCI and dementia: preliminary results

Abstract

Reaching a diagnosis may be difficult in the initial stages of dementia, especially in low educated individuals, when informant reports may be useful.ObjectivesTo compare the sensitivity and specificity of the IQCODE against cognitive tests applied in clinical practice and to evaluate the possible cut-off points in Brazil.MethodsIndividuals without dementia (CDR=0; N=5), with Mild Cognitive Impairment (MCI) (CDR=0.5; N=15) and demented (CDR≥1; N=29) were evaluated using the Short IQCODE, a 16-item questionnaire applied to an informant, and on standard cognitive and functional scales. Diagnosis was reached by a consensus team with expertise in dementia, according to DSM-IV criteria, which was blind to the IQCODE results.ResultsIQCODE scores were positively correlated to the CDR (r=0.65, p<0.001) and negatively correlated with years of schooling (r= –0.33, p=0.021). IQCODE scores were positively correlated with CDR controlled by age and education (r=0.61, p<0.001). Linear regression showed that age was associated with the IQCODE (p=0.016) whereas education was not associated (p=0.078). IQCODE means according to the CDR classification were: CDR 0–3.37; CDR 0.5–3.75; CDR 1–4.32; CDR 2–4.61; CDR 3–5.00. The area under the ROC curve for dementia vs. controls was 0.869 (p<0.001), MCI vs. controls, 0.821 (p<0.001); and according to the groups classified by the CDR was: CDR 0.5 vs. CDR 1=0.649 (p=0.089), CDR 1 vs. CDR 2=0.779 (p=0.009), and CDR 2 vs. CDR 3=0.979 (p=0.023).ConclusionsThese preliminary findings suggest that the short IQCODE can be used for the screening of MCI and dementia in Brazil.

Applying generalizability theory to examine assessments of subjective cognitive complaints: whose reports should we rely on – participant versus informant?

“…The original IQCODE consists of 26 questions/items. An abbreviated version of the IQCODE consisting of 16 items has been found to perform as reliably as the original version (Jorm, 1994, Jorm, 2004, with a number of studies confirming high internal consistency (Cronbach's alpha = 0.93 to 0.97) (Harrison et al, 2015, Phung et al, 2015, Tang et al, 2004) and a superior ability to predict incident dementia (Perroco et al, 2008;Park, 2017). Association, 1994) -that is, the development of one or more cognitive deficit(s) that represent a decline from a previous level of performance and were sufficiently severe as to cause impairment in functioning (Bayer IADL scale score ≥ 3.0).…”

Self-Reported Cognitive Decline on the Informant Questionnaire on Cognitive Decline in the Elderly Is Associated with Dementia, Instrumental Activities of Daily Living and Depression but Not Longitudinal Cognitive Change

“…It is widely used in clinical and research settings and has well-defined psychometric properties [20][21][22]. Informant reports using the IQCODE are unaffected by patient level of education and have a similar sensitivity to cognitive impairment as do traditional screening measures like the Mini-Mental State Examination (MMSE) [22][23][24]. The questionnaire measures the degree of perceived cognitive change (either improvement or decline) over the preceding 10 years, using a 5-point scale and questions regarding functional memory, learning and problem solving.…”

Informant-based questionnaire for early detection of cognitive disorders in the olders in Kazakhstan

“…The detection of dementia is preferably carried out without disturbing the patient much. Surveys of informants are more suitable for this [15]. Questionnaires for informants are extremely useful for clinicians, since these tools are less affected by cognitive reserve than objective cognitive tests [16].…”