Discussion
fatigue
EVENTS, SECONDARY, RECRUITMENT
The present trial showed that despite the higher fatigue score among participants in the COMB group at baseline, their scores dropped significantly across the study time points compared to the fatigue scores of the EXER and control groups. The COMB group also had statistically better immediate and sustained effects to 12 months on reducing aged-induced fatigue in frail older people compared with the EXER group that received exercise training or the control group that received the health talks. A greater improvement in psychological wellbeing was also observed in the COMB group than in the group that received exercise training and in the control group at the 12-month follow-up.The COMB programme also had superior effects than the control group on increasing the participants’ physical endurance in terms of handgrip strength, and in functional mobility as measured by the 2-min walking test and the 30-s chair stand test immediately post-intervention. However, the effect of the COMB programme on all domains of physical functioning did not differ from that of the exercise programme alone, except with respect to upper limb strength immediately post-intervention and at the 12-month follow-up.Both the COMB programme and exercise training alone had superior immediate effects on the participants’ exercise self-efficacy, physical activity levels, and frailty status compared with the control group. These significant positive effects on frailty status could be observed at the 12-month follow-up, but not at the 6-month follow-up. However, the effects of the COMB programme and exercise training alone on the participants’ exercise self-efficacy, physical activity levels, and frailty status were similar, as no significant differences between these two intervention groups could be found at any measurement time point.The results of our study were consistent with those of previous intervention studies, which demonstrated that exercise training could improve physical endurance, physical activity levels, exercise self-efficacy, and reverse frailty status [In our study, the motivational phase of the BCE programme provided participants in the COMB with more psychological preparation and support to encourage them to do the exercises voluntarily instead of being forced. This was achieved by using three key attributes of the HAPA model (i.e., self-efficacy, outcome expectancies, and risk awareness) to enhance their motivation to manage their health problem [The COMB programme used in our trial had better immediate and sustained results than the exercise training alone in reducing general fatigue. This could be because the BCE programme captured the core parts of the participants’ motivation and psychological changes. For older people, psychological wellbeing tends to be important for managing fatigue and symptoms of frailty [The strengths of the present study include methodologically rigorous and long-term follow-ups. This study was designed and conducted strictly following the Consort statement for cluster randomised trials [This study has several limitations that warrant acknowledgement and consideration. Firstly, the actual number of participants was smaller than originally planned due to unforeseeable events, including the social unrest and the COVID-19 pandemic. The sample size was not reduced in the phase of sample size estimation, however the abovementioned incidents negatively affected the recruitment and retention of participants. Although the final sample size of 189 participants seems to have sufficient statistical power to determine changes in levels of fatigue among the three intervention groups at different outcome measurement time points (i.e., based on the GEE analyses on the fatigue scores, please refer to the results section), it seems insufficient for determining the effects on most of the secondary outcomes, particularly the effects between the COMB and the EXER groups. Secondly, the relatively high loss to follow-up, particularly in T3, may induce attrition bias. However, the independent t-test (supplementary information Tables 