Physical activity promotion in lung transplant recipients

Lung transplantation is an established final treatment option for patients with advanced chronic respiratory disease. Despite its success in enhancing pulmonary function and health-related quality of life (HRQoL), limitations in physical and emotional function have been reported to persist in lung transplant recipients. To confirm this notion and to fully understand the level of physical and emotional functioning in these patients, the present thesis compared accelerometry-derived physical activity and HRQoL outcomes between lung transplant recipients and healthy individuals in the UK. Lung transplant recipients displayed significantly lower levels of daily physical activity across a number of parameters, along with significantly lower HRQoL in domains related to physical functioning, highlighting the need for effective interventions to promote physical activity in this population. Physical inactivity in daily life may contribute to impaired recovery of physical functioning following lung transplantation and diminish long-term outcomes. Given the paucity of research into potential interventions to address physical inactivity in lung transplant recipients, the current thesis includes a systematic review of the evidence supporting the benefits of exercise training for lung transplant candidates and recipients. Whilst exercise training appeared to have a positive impact on exercise capacity and HRQoL, the available evidence is low quality and limited by the lack of randomised controlled trials (RCTs). The main study of the present thesis investigated the feasibility, acceptability, and safety of a 3-month behavioural modification physical activity tele-coaching (TC) intervention in lung transplant recipients that has been proof-tested previously in COPD patients. The intervention consisted of a validated, commercially available pedometer that was used as a motivational tool to monitor daily activity, and a smartphone app, allowing transmission of pedometer activity data to a cloud-based platform that provided feedback, activity goals, education, and telephone contact with the researcher when required. The study employed an RCT design to evaluate the potential effect of the intervention, by assessing the short- (3 months) and longer-term (6 months) impact on physical activity, HRQoL, anxiety and depression, compared to usual care (UC). The results showed that key criteria for progressing to a full-scale RCT study were met. Of the 22 patients eligible, 20 were recruited and randomised to TC or UC and 18 completed (67% male; mean ± SD age; 57 ± 10 years; COPD n=5, ILD n=10, CF n=2, PH n=1): TC (n=10) and UC (n=8). TC was well accepted by patients, with 88% indicating that they enjoyed taking part. Usage of the pedometer was excellent, with 80% of patients wearing it for over 90% of days and rating the pedometer and telephone contact as the most vital aspects. There were no adverse events related to the intervention. After 3 months, both TC and UC displayed clinically important improvements in accelerometer steps/day (by 2945±3056 and 1566±1400 steps/day, respectively) and SF-36 physical component summary (PCS) scores, however TC exceeded UC by clinically important margins (by 1379 steps/day and 5 points, respectively). Only the TC group displayed significant improvement in movement intensity (by 138±148 VMU) and time spent in at least light activity (by 43±28 min/day). At 6 months, the TC group maintained improvements gained in physical activity and HRQoL, however the UC group exhibited clinically important declines in daily steps, SF-36 PCS, and anxiety scores. In conclusion, physical activity TC is a feasible, safe, and well accepted intervention in lung transplant recipients. Whilst there is a degree of natural recovery in physical activity and HRQoL following lung transplantation, physical activity TC has the potential to optimise these outcomes. Furthermore, the implementation of behavioural modification strategies resulted in better maintenance of health outcomes beyond the initial intervention period. Therefore, this thesis can inform a full-scale RCT to determine the true short- and long-term effect of physical activity TC in lung transplant recipients, compared to UC