| First author [ref.] | Design and setting | Subjects n (males/females) | Physical activity assessment | Main objective | Correlation coefficient | p-value | Main results |
| Steele [39] | Single-centre convenience sample USA | 47 (44/3) | Accelerometer | Feasibility of accelerometer measurement | 0.62 | <0.001 | Preliminary data suggesting that a triaxial movement sensor is a reliable, valid and stable measure of walking and daily physical activity in COPD patients |
| Belza [91] | Single-centre convenience sample USA | 63 (60/3) | Accelerometer | Evaluation of correlates of physical activity | 0.37 | <0.01 | Physical activity is most significantly related to walking abilities |
| Pitta [74] | Single-centre convenience sample Belgium | 50 (36/14) | Accelerometer | Comparison of physical activity in COPD with healthy subjects | 0.28 | <0.05 | Patients with COPD are markedly inactive in daily life Functional exercise capacity is the strongest correlate of physical activity |
| Walker [80] | Single-centre convenience sample UK | 23 (12/11) | Accelerometer | Evaluation of lower limb activity and the association of laboratory assessments with physical activity before and after rehabilitation in COPD | 0.57 | <0.001 | Physical activity in patients with COPD is closely related to leg activity, which is reduced compared with controls of similar age |
| Hernandes [77] | Single-centre convenience sample Brazil | 40 (18/22) | Accelerometer | Evaluation of physical activity and its clinical correlates in COPD in Brazil | 0.17 | ns | Physical activity correlates only moderately with maximal and functional exercise capacity |
| Watz [65] | Single-centre convenience sample Germany | 163 (122/41) | Accelerometer | Various analyses of physical activity and its clinical correlates in COPD | 0.42 | <0.01 | Clinical characteristics of patients with COPD only incompletely reflect their physical activity |
| Waschki [79] | Multi-centre convenience sample UK, the Netherlands | 127 (79/48) | Accelerometer | Evaluation of compliance with wearing an accelerometer and the relationship of disease characteristics with physical activity in a multicentre study | 0.65#] | <0.001 | Excellent compliance with wearing a physical activity monitor in a multicentre study Consistent associations of physical activity with relevant disease characteristics in a multicentre study |
↵FEV1: forced expiratory volume in 1 s; COPD: chronic obstructive pulmonary disease; ns: nonsignificant. #: Standardised regression β-coefficient adjusted for age, sex, study site and body mass index >30 kg·m−2.