Clinical Frailty Scale: translation and cultural adaptation into the Brazilian Portuguese language

Background: Frailty is a biological syndrome that causes adverse events in the health of older adults. However, the Clinical Frailty Scale has not yet been culturally adapted and validated into Brazilian Portuguese language. Objectives: Our aim was to translate, reproduce and validate the Clinical Frailty Scale (CFS) for the Brazilian Portuguese language. Design: An observational cross-sectional study with senior patients was conducted between Jan 2018 and Nov 2018. Setting and Participants: Volunteers aged >60 and living in Brazil. The translation and cultural adaptation of the CFS into the Portuguese language, the principles and good practices were followed. Measurements: To conduct the validation and determine the reproducibility of an inter-observer evaluation, the patients answered the scale questions in Portuguese on two occasions, delivered by two separate examiners and separated by a 10-minute interval, on their first visit; the 36-item Short Form Survey quality-of-life questionnaire (SF-36) was also applied. Seven days later, a second visit was undertaken to perform an intra-observer reproducibility assessment. Results: A total of 66 older individuals were enrolled (72 ± 8 years), the majority of which did not present frailty (63.6%) and reported a low physical limitation level in the SF-36. The CFS showed a significant correlation with the SF-36 quality-of-life questionnaire (r= −0.663; p<0.0001) and no statistical difference was observed between intra-rater (p=0.641) and inter-rater (p=0.350) applications, demonstrating the reproducibility and applicability of the instrument. The standard error estimate (SEE) was evaluated and there were no differences between the CFS and the SF-36 (SEE= 1.13 points). Conclusion: The Brazilian Portuguese language version of the CFS is a valid, reproducible and reliable instrument for evaluating the impact of frailty on the lives of senior patients.