Figure 3: Effect of various ACE inhibitors on all-cause mortality among patients with congestive heart failure. Variables included in the models: fiscal year of admission, province of admission, length of stay, time to first ACE inhibitor prescription, specialty of treating physician, hospital characteristics (teaching v. nonteaching, volume of admissions because of congestive heart failure), comorbidities and prescriptions filled for other cardiac medications). The fixed-exposure model includes data from Quebec, Ontario and British Columbia. The time-dependent model includes data from Quebec and Ontario only. CI = confidence interval.