Fig. 4From: Clinical variables predicting the risk of a hospital stay for longer than 7 days in patients with severe acute exacerbations of chronic obstructive pulmonary disease: a prospective studyThe readmission rates were evaluated for the periods ≤30 days and > 30 days from discharge. White and grey represent the AECOPD patients with normal LHS and prolonged LHS, respectivelyBack to article page