Figure 2.

Hazard ratio (HR) of lung volume reduction surgery (LVRS) to medical treatment for decline of at least a nine-point increase in the total St. George's Respiratory Questionnaire (SGRQ) score or composite event. Discrete hazard ratios are shown for the following samples of patients: (A) All patients in the study. (B) Patients without a high risk of perioperative mortality. (C) Patients without high risk for perioperative mortality, and with upper-lobe–predominant emphysema, and high exercise capacity. (D) Patients without high risk for perioperative mortality, upper-lobe–predominant emphysema, and low exercise capacity. (E) Patients without high risk for perioperative mortality, non–upper-lobe predominant emphysema, and high exercise capacity. (F) Patients without a high risk for perioperative mortality, non–upper-lobe predominant emphysema, and low exercise capacity. Black lines indicate HRs for the composite event, which is the occurrence of death or the occurrence of an at least eight-point or higher increase in the total score on the SGRQ, whichever happened first. Gray lines indicate HRs for an at least eight-point increase in the total SGRQ score only. An HR of greater than one favors the medical treatment group for the specific endpoint, and an HR of less than one favors the LVRS group for the specific endpoint. *Statistical significance (P < 0.05).