What are the characteristics of outpatients with chronic obstructive pulmonary disease who have reduced physical activity as a result of low-frequency pulmonary rehabilitation?

[Purpose] This study retrospectively examined the physical characteristics of patients with chronic obstructive pulmonary disease who experienced decreased physical activity due to low-frequency pulmonary rehabilitation. [Participants and Methods] Eighty outpatients with stable chronic obstructive pulmonary disease were included. Participants were categorized into two groups based on changes in physical activity after six months of low-frequency pulmonary rehabilitation. Those whose daily step count decreased by 600 steps or more were classified as the decreased group, while the others were classified as the non-decreased group. [Results] The decreased group had a lower predicted value of forced expiratory volume in one second compared to the non-decreased group. Additionally, a greater proportion of participants in the decreased group lived in hilly areas compared to those living in flat areas. [Conclusion] It may be important to consider appropriate intervention strategies at the initial assessment of low-frequency pulmonary rehabilitation, especially for individuals with reduced forced expiratory volume in one second and those living in hilly environments.