Frailty and quality of life: a cross-sectional study of Brazilian patients with pre-dialysis chronic kidney disease

Purpose: Chronic kidney disease (CKD) induces frailty and worsens quality of life (QOL), even in the early stages of the disease and in young patients. However, there is a lack of knowledge about the relationship between frailty and QOL in CKD patients. Thus, we investigated this relationship in a sample of CKD patients. Methods: A cross-observational study was conducted, in which 61 CKD patients receiving pre-dialysis treatment were assessed. All participants completed the Short Form-36 Health Survey (SF-36). We used valid and reliable methods to classify subjects as frail or non-frail according to Johansen's et al. (2007) criteria. A one-way analysis of variance (ANOVA) and chi-square tests were used to compare the groups. In addition, Spearman's correlation analysis was conducted to measure associations between identified variables and frailty. We also performed simple linear regression using the SF-36 physical and mental composite scores. Results: Almost half of the sample (42.6%) exhibited evidence of frailty. The groups differed significantly in terms of age, gender, and all SF-36 domains, excluding Social Functioning and Role Emotional. Frailty was significantly associated with all SF-36 domains, again excluding Social Functioning and Role Emotional. Regression analysis revealed no significant between-group differences in composite physical and mental health scores generated by the SF-36 (p > 0.05). Conclusion: Frail and non-frail CKD patients differed significantly in seven of the eight SF-36 domains. The frail group displayed diminished physical and mental functioning when their SF-36 scores were divided by their physical and mental composite scores. Frailty was correlated with QOL domains, with the exception of the social domain. There is a need for interventions targeting the characteristics of frailty, to provide better treatment and optimize overall QOL.