Randomised factorial mixed method pilot study of aerobic and resistance exercise in haemodialysis patients: DIALY-SIZE!

Objectives: For people with end-stage renal disease requiring haemodialysis, exercise can improve aspects of quality of life (QoL). However, the relative benefits and risks of different types of exercise in this population are unknown. Therefore, this pilot study aimed to evaluate the feasibility of a main study evaluating the efficacy of cycling and resistance exercise each performed during the haemodialysis treatment on QoL. Methods: In this factorial (2x2) pilot trial, 31 haemodialysis patients were randomised to cycling, resistance, cycling and resistance, or an attention control. Feasibility was defined a priori by criteria on recruitment, fidelity to the protocol and patient response to the intervention. To better understand feasibility, we conducted interviews with dialysis unit staff and trial participants. As secondary outcomes, we estimated the main effect of cycling and weights each compared with control on QoL, physical function and strength. Findings: We exceeded the target accrual of 28 participants over 12 weeks. Irrespective of exercise group allocation, adherence was high; of the 1038 training sessions offered, 87% were initiated and over 80% of exercise sessions were performed as per protocol. Progression based on perceived exertion, individual instruction and interactions with the kinesiologist facilitated acceptability across exercise groups. Using an attention control, measures of contamination and attrition were low. Important barriers to unit staff readiness for the intervention were initial safety and workflow concerns, unit workload and onerous data collection. Secondary outcomes were not statistically significant. Adverse events were low and did not increase with a higher volume of exercise. Conclusions: The main study is feasible with minor modifications. In addition to practical assistance, involvement from unit staff could increase patient participation and improve trial implementation. Strategies to increase acceptability of the intervention for staff include improving workflow integration and using a prestudy demonstration phase to introduce the intervention.