A Behaviour Change Intervention Promoting Physical Activity Following Dysvascular Amputation: a Pilot Study

Background and Importance: Diabetes-related lower limb amputation (LLA) is a leading cause of disability globally, impacting individuals' physical and mental health and ultimately their quality of life. Individuals with LLA due to diabetes or other vascular disease (dysvascular LLA) often have comorbidities, including higher rates of cardiovascular disease than the general population. They are at risk of amputation in the contralateral limb and have high mortality rates (30% at one year).

There is strong evidence demonstrating that physical activity reduces risk of chronic disease and mortality and improves quality of life. However, people with dysvascular LLA often have reduced strength, balance, walking ability and increased energy expenditure during ambulation. Consequently, they have impaired mobility that can lead to sedentary behaviour. Across studies examining physical activity in people with dysvascular LLA, step counts ranged from 1250 steps/day in older prosthesis users to 3809±2189 steps/day in people with diabetes-related LLA. Unfortunately, limited availability of rehabilitation services for people with LLA and the high cost of delivering healthcare interventions makes provision of support for physical activity challenging. To address this gap, we co-created a physical activity intervention, IMproving Physical Activity through Coaching and Technology following Lower Limb Loss (IMPACT-L3), to support physical activity behaviour change in people with dysvascular LLA. Prior to launching a large trial, a pilot study is required to assess feasibility and optimize design of a future trial. This study aims to assess the feasibility of conducting a definitive randomized controlled trial (RCT) to determine the effectiveness of a virtual peer-led physical activity intervention on levels of physical activity and self-efficacy in people with dysvascular LLA. Specific objectives are to: 1) evaluate feasibility according to indicators of process, resources, management and treatment; 2) explore perceptions of program characteristics, program implementation and study procedures among individuals with LLA; 3) explore the perceived feasibility and acceptability of the program among peer coaches; and 4) inform a sample size calculation for a future trial of effectiveness.

Methods: This pilot study is a parallel group RCT with an embedded qualitative component. The intervention group will have access to once-weekly virtual peer coaching sessions with a gender and level of amputation-matched peer trained in brief action planning; web-based physical activity modules; and a wearable activity monitor for 8 weeks. The control group will continue their usual health care and be offered the intervention at the end of the follow-up period. Data on feasibility of implementing the intervention and conducting the trial will be collected including assessment of process, resource, management and treatment indicators. Progression Criteria: A traffic light approach (red, amber, green) will be used to guide the research team in determining what changes may be required to address identified challenges based on the indicators and in determining the feasibility of progression to a trial. The proposed primary outcomes for a future trial will be measured at baseline, post intervention (week 9) and 4 week follow-up: total physical activity counts per day measured by the ActiGraphTM activity monitor and self-efficacy measured by the Self-efficacy for Exercise scale. Other outcome measures include: the Physical Activity Scale for Individuals with Physical Disability, Frenchay Activity Index, the Center for Epidemiologic Studies Depression Scale, Activities-specific Balance Confidence scale, Prosthesis Evaluation Questionnaire - Mobility Section, and Short Form Health Survey 12 Item survey. Semi-structured interviews will explore feasibility and acceptability of the intervention to participants (~15-20 participants) and peers. Inductive thematic analysis will be employed to analyze qualitative interviews.