The development and feasibility of an intervention to promote physical activity following pulmonary rehabilitation in people with Chronic Obstructive Pulmonary Disease

Background: Despite the importance of physical activity to physical and psychological health in chronic obstructive pulmonary disease (COPD), levels of physical activity in COPD patients are significantly lower than age matched healthy individuals. Pulmonary rehabilitation, a structured physical activity intervention, is one of the essential treatments for COPD, and results in benefits such as improved exercise capacity, symptoms, and quality of life. However, this does not translate to an increase in long term physical activity and previous interventions to promote physical activity following pulmonary rehabilitation have had limited efficacy. Aim: The overarching aim of this thesis was to develop and test the feasibility and acceptability of an intervention to promote physical activity following pulmonary rehabilitation in patients with COPD. Methods: This mixed methods thesis developed and tested the feasibility of an intervention in line with the stages outlined in the Medical Research Council framework. The intervention was informed by a qualitative systematic review and the development of the intervention was facilitated by the Behaviour Change Wheel and collaboration with stakeholders. The intervention was tested in a feasibility cluster randomised controlled trial with an embedded process evaluation. The primary outcome of the feasibility study was the acceptability of the intervention and secondary outcomes included other feasibility outcomes and a range of clinical measures proposed for a definitive trial. Acceptability of the intervention and the research procedures were also explored via semi-structured interviews with patients and focus groups with personnel involved in delivery of the intervention (health care professionals and WhatsApp leaders). An inductive analysis was conducted to analyse the data. The factors which impacted patients’ physical activity were also identified via a deductive analysis of the interviews with patients, and mapped to the capability, opportunity, motivation behaviour change model (COM-B). Results: A thematic synthesis of fourteen studies revealed that beliefs, social support, and the environment encapsulate the factors which are important in physical activity following pulmonary rehabilitation in patients with COPD. The Behaviour Change Wheel guided the development of an intervention that included the provision of a pedometer and step diary, and the addition of patients to a WhatsApp group populated by fellow pulmonary rehabilitation graduates and a ‘WhatsApp leader’ for 52 weeks following pulmonary rehabilitation. A total of 74 patients enrolled in the feasibility study (consent rate, 55%) and there was an attrition rate of 35% at 52 weeks. By 52 weeks, 49% had engaged in the step diary, and 58% of participants who had consented to use WhatsApp had sent at least one WhatsApp message to the group. The Control Group had a larger decline in their daily steps at 52 weeks compared to the Intervention Group, MD, -180, (-765, 1126). Participants in the intervention group who engaged in the step diary had a smaller decline in their daily steps at 52 weeks compared to those who did not engage in the step diary, MD, 45.5 (-1796, 1889). Participants in the intervention group who engaged in WhatsApp had a smaller decline in daily steps at 52 weeks compared to those who did not engage in WhatsApp, MD, 730 (-992, 2454). However, results also suggest there was a larger detrimental decline in secondary health outcomes in the Intervention Group compared to the Control Group. WhatsApp leaders adhered to sending a minimum of weekly physical activity messages throughout the 52 weeks period. Common themes from interviews and focus groups were that patients would benefit from more familiarity with the intervention components (e.g. earlier introduction of the intervention to patients during PR from health care professionals), and that the convenience of the intervention components and research procedures could be improved (e.g. options for participants to use their personal mobile and pedometer devices). Rapport between the patients and WhatsApp leaders was considered important and face to face support should complement social networking following Pulmonary Rehabilitation. Facilitators unique to those with higher intervention engagement related to physical capability and reflective motivation (e.g. reduction in exacerbations following Pulmonary Rehabilitation and the ability to overcome mental obstacles). Barriers unique to those with lower intervention engagement related to automatic motivation and physical opportunity (e.g. low mood and the distance of physical activity opportunities). Conclusion: This thesis addressed the gaps in previous literature and adopted a step wise approach in the development and feasibility testing of the intervention. The intervention was considered acceptable and feasible, yet modifications are required to optimise the acceptability and feasibility of the study prior to a definitive cluster randomised controlled trial, which are possible during an intervention revision period