The PrEscription of intraDialytic exercise to improve quAlity of Life (PEDAL) in patients with chronic kidney disease trial: Study design and baseline data for a multi-centre randomised controlled trial.

Background: Exercise interventions designed to improve physical function and reduce sedentary behaviour in haemodialysis (HD) patients might improve exercise capacity, reduce fatigue and lead to improved quality of life (QOL). The PEDAL study aimed to evaluate the effectiveness of a 6-month intradialytic exercise programme on quality of life (QOL) and physical function, compared to usual care for patients on HD in the UK.

Methods: We conducted a prospective, pragmatic multicentre randomised controlled trial (RCT) in 335 HD patients and randomly (1:1) assigned them to either, i) intradialytic exercise training plus usual care maintenance HD, or ii) usual care maintenance HD. The primary outcome of the study was the change in Kidney Disease Quality of Life (KDQOL-SF 1.3) Physical Component Score between baseline and 6 months. Additional secondary outcomes included changes in: peak aerobic capacity, physical fitness, habitual physical activity levels and falls (International Physical Activity Questionnaire, Duke’s Activity Status Index and Tinetti Falls Efficacy Scale), quality of life and symptom burden assessments (EQ5D), arterial stiffness (pulse wave velocity), anthropometric measures, resting blood pressure, clinical chemistry, safety and harms associated with the intervention, hospitalisations, and cost-effectiveness. A nested qualitative study investigated the experience and acceptability of the intervention for both participants and members of the renal healthcare team.

Results: At baseline assessment, 62.4% of the randomised cohort were male, the median age was 59.3 years, and 50.4% were White. Prior cerebrovascular events and myocardial infarction (MI) were present in 8 and 12% of the cohort, respectively, 77.9% of patients had 3

hypertension and 39.4% had diabetes. Baseline clinical characteristic and laboratory data for the randomised cohort were generally concordant with data from the UK Renal Registry.

Conclusion: The results from this study will address a significant knowledge gap in the prescription of exercise interventions for patients receiving maintenance HD therapy and inform the development of intradialytic exercise programmes both nationally and internationally.

Trial Registration: ISRCTN N83508514; registered on 17th December 2014.