A behaviour change intervention to reduce sedentary time in people with chronic obstructive pulmonary disease: protocol for a randomised controlled trial

Abstract

Introduction: Replacing sedentary behaviour with light intensity physical activity (ie, activities classified as less than three metabolic equivalents, such as slow-paced walking) may be a more realistic strategy for reducing cardiometabolic risk in people with chronic obstructive pulmonary disease than only aiming to increase levels of moderate-vigorous intensity physical activity. Behaviour change interventions to reduce sedentary behaviour in people with chronic obstructive pulmonary disease have not yet been developed or tested.

Research questions: Is a 6-week behaviour change intervention effective and feasible in reducing sedentary time in people with chronic obstructive pulmonary disease?

Design: This study will be a multi-centre, randomised, controlled trial with concealed allocation, assessor blinding, and intention-to-treat analysis, comparing a 6-week behaviour change intervention aimed at reducing sedentary time with a sham intervention in people with chronic obstructive pulmonary disease.

Participants and setting: Seventy participants will be recruited from the waiting lists for pulmonary rehabilitation programs at Royal Prince Alfred Hospital and Prince of Wales Hospital, Sydney, Australia.

Intervention: The behaviour change intervention aims to reduce sedentary time through a process of guided goal setting with participants to achieve two target behaviours: (1) replace sitting and lying down with light-intensity physical activity where possible, and (2) stand up and move for 2minutes after 30minutes of continuous sedentary time. Three face-to-face sessions and three phone sessions will be held with a physiotherapist over the 6-week intervention period. The 'capability', 'opportunity', 'motivation' and 'behaviour' (COM-B) model will be applied to each participant to determine which components of behaviour (capability, opportunity or motivation) need to change in order to reduce sedentary time. Based on this 'behavioural diagnosis', the Behaviour Change Wheel will be used to systematically select appropriate behaviour change techniques to assist participants in achieving their weekly goals. Behaviour change techniques will include providing information about the health consequences of sedentary behaviour, self-monitoring and review of weekly goals, problem-solving of barriers to achieving weekly goals, and providing feedback on sedentary time using the Jawbone UP3 activity monitor.

Control: The sham intervention will consist of weekly phone calls for 6 weeks, to enquire whether the participants' health status has changed over the intervention period (eg, hospitalised for an acute exacerbation). No instructions regarding physical activity or exercise will be given.

Measurements: Outcomes will be assessed at baseline, at the end of the 6-week intervention period, and at the 3-month follow-up. Primary outcome measures will be: (1) total sedentary time, including the pattern of accumulation of sedentary time, assessed by the activPAL3 activity monitor, and (2) feasibility of the intervention assessed by uptake and retention of participants, participant compliance, self-reported achievement of weekly goals, and adverse events. Secondary outcome measures will include functional exercise capacity, health-related quality of life, domain-specific and behaviour-specific sedentary time, patient activation, and anxiety and depression. Semi-structured interviews will be conducted with participants who receive the behaviour change intervention to explore acceptability and satisfaction with the different components of the intervention.

Analysis: Analysis of covariance (ANCOVA) will be used to calculate between-group comparisons of total sedentary time and the number of bouts of sedentary time>30minutes after adjusting baseline values. Uncertainty about the size of the mean between-group differences will be quantified with 95% CI. Within-group comparisons will be examined using paired t-tests and described as mean differences with 95% CIs. Secondary outcome measures will be analysed similarly. The feasibility measures will be analysed descriptively. Semi-structured interviews will be conducted until data saturation is achieved and there are no new emerging themes. De-identified interview transcripts will be coded independently by two researchers and analysed alongside data collection using the COM-B model as a thematic framework.

Discussion/significance: If behaviour change interventions are found to be an effective and feasible method for reducing sedentary time, such interventions may be used to reduce cardiometabolic risk in people with chronic obstructive pulmonary disease. An approach that emphasises participation in light-intensity physical activity may increase the confidence and willingness of people with chronic obstructive pulmonary disease to engage in more intense physical activity, and may serve as an intermediate goal to increase uptake of pulmonary rehabilitation.