Accuracy of the Brazilian Version of the Informant Questionnaire on Cognitive Decline in the Elderly at Screening for Dementia in Community-Dwelling Elderly Participants: Findings From FIBRA-RJ Study

Objectives: To determine the accuracy of the Brazilian version of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE-BR) for screening for dementia and to analyze the association of sociodemographic variables of the elderly participants and informant, as well as the mental health of the informant, in the scores of the questionnaire. Methods: A cross-sectional study was carried out with 417 elderly participants and their informants from the sample of the Frailty in the Brazilian Elderly Study, Rio de Janeiro, Brazil. The older individuals were assessed by clinical, functional, and neurocognitive evaluation, and the diagnosis of dementia was established according to Diagnostic and Statistical Manual of Mental Disorder (Fourth Edition) criteria. The informants were evaluated by Mini-Mental State Examination (MMSE), Center of Epidemiologic Studies-Depression Scale, and Burden Interview Scale. The Cambridge Cognitive Examination Test-Revised (CAMCOG-R) was used for convergent validity analysis. The association between IQCODE-BR and the study variables was determined by multivariate logistic regression analysis. Results: The best cutoff point was 3.26; the sensitivity, specificity, and area under the receiver-operating characteristic curve were 89%, 72%, and 0.88 (95% confidence interval: 0.837-0.917), respectively. The CAMCOG-R and the MMSE showed a moderate and negative association with IQCODE-BR. Conclusion: The IQCODE-BR is an instrument with good accuracy for the detection of dementia syndrome in Brazilian older person.