Abstract
INTRODUCTION: Physical capacity is an important determinant of physical activity in people with obstructive airway disease (OAD). This study aimed to extend the "can do, do do" concept in people with OAD, to identify if people categorised into quadrants based on physical capacity and activity differ by clinical and movement behaviour characteristics. METHODS: A total of 281 participants (bronchiectasis n=60, severe asthma n=93, COPD n=70 and control n=58) completed assessments to characterise physical capacity as "can do" versus "can't do" (6-min walk distance < or ≥70% pred) and physical activity as "do do" versus "don't do" (accelerometer-derived moderate to vigorous intensity physical activity (MVPA) < or ≥150 min·week(-1)). RESULTS: The control group had a greater proportion of people in the "can do, do do" quadrant compared with the OAD groups (76% versus 10-33%). People with OAD in the "can't do, don't do" quadrant had worse clinical characteristics (airflow limitation, comorbidities, quality of life and functional dyspnoea) and spent less time doing light-intensity physical activity (LPA) and more time being sedentary compared with the "can do, do do" quadrant. DISCUSSION: This study highlights that many people with OAD may be inactive because they do not have the physical capacity to participate in MVPA, which is further impacted by greater disease severity. It is important to consider the potential benefits of addressing LPA and sedentary behaviour due to suboptimal levels of these movement behaviours across different quadrants. Future research is needed to investigate if tailoring intervention approaches based on quadrant allocation is effective in people with OAD.