Frailty and physical function in chronic kidney disease: the CanFIT study

BACKGROUND: Frailty, a manifestation of unsuccessful aging, is highly prevalent in people with chronic kidney disease (CKD) and is associated with comorbid conditions in cross-sectional studies. Longitudinal studies investigating the progression of frailty in those with advanced non-dialysis CKD are lacking. OBJECTIVES: Canadian Frailty Observation and Interventions Trial (CanFIT). To determine the natural history, prevalence of perceived and measured frailty and its association with dialysis treatment choices and adverse outcomes in patients with advanced CKD. DESIGN: Longitudinal observational study, designed to collect data from 600 participants over 2 years. SETTING: Interprofessional non-dialysis CKD clinics at four tertiary health care centres in central Canada. PATIENTS: People with CKD stage 4 and 5 (eGFR <30 ml/min/1.73 m(2)) who are not on dialysis at enrollment. MEASUREMENTS: Multiple Frailty Definitions: Short Physical Performance Battery (SPPB), Fried Frailty Criteria, Frailty Index. Dialysis start: In-Centre Hemodialysis, Home Hemodialysis or Peritoneal Dialysis Outcomes: Death, Opt-out or Lost to follow up. METHODS: We will perform physical and cognitive assessments annually. We plan to analyze the relationships between frailty, treatment choices and patient centered outcomes. RESULTS: We have recruited 217 participants in 2 centres; of these, 56 % had reduced physical function at baseline, as defined by the SPPB. Risk of reduced physical function was 8 fold higher in those with diabetes after adjusting for age, gender, eGFR and comorbidities. LIMITATIONS: Referred population, use of SPPB as a measure of frailty, inter-operator variability in measurement of hand grip and gait speed, cross-sectional analysis of baseline data in the subset recruited to date. CONCLUSIONS: People with advanced CKD have a high burden of reduced physical function, especially those with diabetes. We will continue enrollment into the CanFIT study to further understand the clinical history of CKD and frailty in this population.