Lower muscle mass, malnutrition, anaemia and depression—all of these, plus elevated mortality, are associated with lower rates of physical activity in patients with end-stage kidney disease (ESKD). Compounding the problem for many such patients is the fact that, as noted in a 2021 observational study led by Rakesh Malhotra (University of California San Diego, San Diego, USA), those receiving haemodialysis for their condition frequently have lower rates of physical activity. Now, Malhotra has led a new study in the American Journal of Kidney Diseases (AJKD) investigating how a wearable activity tracker combined with a feedback programme can increase those rates.
Building on previous work which has incorporated digital technology-based interventions for physical activity in those with other chronic diseases, Malhotra et al turned their focus specifically to those receiving haemodialysis by designing a “weekly structured feedback intervention guided by a wearable activity tracker”. This incorporated not only the technology but also comprehensive feedback and guidance for patients, an intervention they contrasted with the use of the tracker alone. The authors’ hypothesis, they say, was that “equipped with activity data, sequentially informing participants quantitatively about their levels of physical activity relative to other patients receiving haemodialysis would promote greater physical activity in this high-risk population” than leaving patients to assess the data themselves.
The study was designed as a 12-week, two-arm randomised controlled pilot trial in a single haemodialysis centre. There, 55 patients were enrolled who were able to walk either with or without an assistive device, between January 2019 and January 2020, of whom 46 completed the 12-week programme, with half receiving the device plus a weekly feedback session and the other half using the device alone. The patients’ level of physical activity was measured using a step counter in the wearable device, with weekly step count average set as the primary outcome.
Adherence to use of the tracker was >90% in the structured feedback group throughout the 12 weeks and 3% lower in the non-feedback group. On the primary outcome, an intention-to-treat analysis found that those in the structured feedback group experienced a statistically greater increase than the non-feedback group over the 12 weeks (920±580 versus 281±186; between-group difference Δ639 [standard deviation 538] steps; p<0.05). The change, state the authors, “occurred rapidly over the first four weeks and appeared sustained over the 12-week study”. They also report that the difference in activity was “large across arms, both in terms of their potential impact on downstream clinical changes, and statistical significance”.
While the study is limited by a small sample size and short duration, the latter meaning there is little data on the likelihood of long-term adherence, Malhotra and colleagues make the case that it nevertheless shows that “a structured feedback intervention is feasible” and shows promise for improving haemodialysis patient physical activity. “Future studies”, they added finally, “should focus on evaluating the impact of this intervention on longer-term sustainability and downstream health changes.”