How much time spent per day in sedentary behavior increases mortality risk in patients with COPD?

To propose a cut-off point for sedentarism in patients with COPD and to investigate its association with mortality. Methods: In this retrospective cohort study, sedentary behaviour was assessed with two activity monitors (DynaPort and Sensewear armband) in 101 patients with COPD from 2006 to 2011.