Psychometric characteristics of the full and short versions of the IQCODE-BR among low income elderly persons with a low educational level

Objective : To study the psychometric characteristics of the Brazilian Portuguese version of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE-BR) using a sample of low income elderly persons with a low educational level, and compare the full and short versions of the questionnaire. Method : A cross-sectional study of a convenience sample of a population with a low educational level was performed. The IQCODE-BR was applied to the informants of 87 elderly persons (60-90 years old), who were triaged by psychiatrists and neurologists for the diagnosis of depression, mild cognitive impairment (MCI), and dementia. Results : The median age of the sample was 72 and the majority were women (72.4%). A total of 31 (35.6%) were illiterate, 30 (34.5%) had dementia, 21 (24.1%) suffered from depression, 20 (23.0%) had MCI, and 16 (18.4%) were diagnosed with none of these conditions. The median IQCODE-BR was higher in the groups with depression and MCI than the normal group, and was highest of all in the group with dementia. The full and reduced versions of the IQCODE-BR had similar levels of accuracy. Conclusion : In this sample the IQCODE-BR was shown to be an effective tool for tracking MCI and dementia. The use of the short version with cut-off points of 3.22 for MCI excluding a diagnosis of depression, and 3.48 for dementia irrespective of the presence of symptoms of depression, is suggested.