Impacts of Regular Physical Activity on Hospitalization in Chronic Obstructive Pulmonary Disease: A Nationwide Population-based Study

<bold>Introduction:</bold> Physical activity(PA) is an independent predictor of acute exacerbation and risk of hospitalization for premature death in patients with chronic obstructive pulmonary disease(COPD). However, studies that comprehensively evaluate the association between PA levels, particularly by quantifying PA intensity, and healthcare use requiring emergency department(ED) visit or hospitalization in patients with COPD are limited. <bold>Methods:</bold> The risk of all-cause and respiratory ED visit or hospitalization according to the presence or absence of COPD and the level of PA was evaluated in a retrospective nationwide cohort comprising 3,308 subjects with COPD and 293,358 subjects without COPD from 2009 to 2017. <bold>Results:</bold> Compared with the highly physically active control group, the relative risk of all-cause and respiratory ED visit or hospitalization in the COPD group was higher across all PA levels, with the highest risk of ED visit or hospitalization in the sedentary group (adjusted hazard ratio[HR][95% confidence interval{CI}]=1.70[1.59–1.81] for all-cause ED visit or hospitalization, 5.45[4.86–6.12] for respiratory ED visit or hospitalization). A nonparametric Cox model with a penalized spline showed that increased PA was associated with reduced all-cause and respiratory ED visit or hospitalization in the COPD cohort. Similarly, a 500 MET-min/week increase in PA was associated with reductions in all-cause and respiratory ED visit or hospitalization in the COPD cohort. <bold>Conclusions:</bold> Compared with the presumed healthiest cohort, the control group with PA>1500 METs-min/week, the COPD group with reduced PA has a higher risk of ED visit or hospitalization.