Figure 1.

 The use of β‐blockers in patients with chronic obstructive pulmonary disease (COPD) is associated with a higher survival rate than non‐use. The symbols “+” and “o” denote time points at which individuals who were (“o”) and were not (“+”) taking β‐blockers either died or dropped out of the study (ie, were “censored”). Adapted with permission from Rutten and colleagues. ⁷⁴