Figure 1.

Exacerbation frequency associated with β-blocker use by dichotomized ventricular sizes and dichotomized sphericity indices for right (RV) and left (LV) ventricles. All exacerbation frequencies are expressed as incidence rate ratio (IRR) with 95% confidence intervals. All IRR adjusted for age, sex, race, pack-years of smoking, body mass index, FEV₁, percent emphysema on computed tomography, log-transformed coronary artery calcification, presence of coronary artery disease and congestive heart failure, long-acting respiratory medications (long acting β-agonists/inhaled corticosteroids and long-acting antimuscarinics), and the propensity to prescribe β-blocker therapy.