TRANSLATION AND CROSSCULTURAL ADAPTATION OF THE BRAZILIAN VERSION OF THE COGNITIVE FUNCTION INSTRUMENT FOR EVALUATION OF SUBJECTIVE COGNITIVE DECLINE

Abstract

Historically, mild cognitive impairment was considered the first clinical manifestation of Alzheimer's disease. However, several epidemiological studies have shown that individuals with subjective decline experience a higher risk of progression to dementia due to Alzheimer's disease. In addition, there is evidence of a higher prevalence of positive biomarkers for amyloidosis and neurodegeneration in this group. However, due to the lack of consensus on how to define and evaluate subjective cognitive decline, it is still unclear which features suggest the preclinical stage of Alzheimer's disease and how it would be possible to differentiate them from individuals with subjective cognitive complaints by another etiology, such as psychiatric disorders. The objective of the study was to translate to Portuguese and to perform a cross-cultural adaptation of a Brazilian version of Cognitive Function Instrument (CFI). It is an instrument developed by the Alzheimer's Disease Cooperative Study Group for evaluation of Subjective Cognitive Decline. The project consisted of a cross-sectional study where the original instrument in English was translated and adapted into the Portuguese language. The sample consisted of individuals recruited from among the patients' caregiver from the Cognitive Neurology outpatient clinic of the Medical School of University of São Paulo. This transcultural translation and adaptation process consisted of six stages: initial translation by two translators, synthesis, back translation by two others translators, review by a committee of experts and pretesting of a draft. The preliminary version was applied in 37 individuals. The mean age was 63.5 years with an average of 10.4 years of schooling. In final review, decisions taken by the committee of experts sought to obtain semantic, idiomatic, experimental and conceptual equivalence between the source and the translated version. Throughout the process, all problems found were solved to ensure the quality of the instrument and its appropriateness to the target population. We elaborated a translated and adapted version of an instrument that can be applied to evaluate Subjective Cognitive Decline in the Brazilian population. This instrument is being validated in a cohort of normal elderly without and with subjective cognitive decline and compared with biomarkers of Alzheimer's disease.