1. Date of download: 7/9/2016 From: Cost-Effectiveness of Implantable Cardioverter Defibrillators Relative to Amiodarone for Prevention of Sudden Cardiac Death Ann Intern Med. 1997;126(1):1-12. doi:10.7326/0003-4819-126-1-199701010-00001 Schematic representation of the decision model.Figure 2Figure 2Figure 2Figure 2The square node represents a decision to use one of three treatment regimens: implantable cardioverter defibrillator (ICD) only, amiodarone only, or amiodarone-to-ICD (see Methods). Circles represent chance nodes. After a regimen is chosen, the patient enters a Markov tree (denoted by rectangles containing circles and an arrow). A patient who receives the ICD-only regimen enters the Markov tree only if he or she survives ICD implantation. The Markov trees represent the clinical events that can occur during each 1-month period as a patient is followed until death. For example, a patient receiving the ICD-only regimen is at risk each month for ventricular tachycardia (VT), ventricular fibrillation (VF), nonarrhythmic cardiac death, and noncardiac death. If none of these events occur, the patient remains “well” for the 1-month period. A patient who is well at the end of a month reenters the Markov tree. The braces represent subtree notation and indicate that a patient who has VT or VF enters the arrhythmia subtree, which is shown in the top panel of. Subtrees are denoted by rounded rectangles. Patients receiving the amiodarone-only or the amiodarone-to-ICD regimen are at risk for VT, VF, nonarrhythmic cardiac death, noncardiac death, and toxicity from amiodarone. If toxicity from amiodarone occurs, the patient enters the amiodarone toxicity subtree (, bottom). For the amiodarone-to-ICD treatment regimen, the events that occur after a patient has an arrhythmia depend on the type of arrhythmia experienced. A patient who has VT enters the amiodarone-to-ICD VT subtree (, upper middle); a patient who has VF enters the amiodarone-to- ICD VF subtree (, lower middle). Figure Legend: Copyright © American College of Physicians. All rights reserved.American College of Physicians

2. Date of download: 7/9/2016 From: Cost-Effectiveness of Implantable Cardioverter Defibrillators Relative to Amiodarone for Prevention of Sudden Cardiac Death Ann Intern Med. 1997;126(1):1-12. doi:10.7326/0003-4819-126-1-199701010-00001 Decision model subtrees.Top.Figure 1Upper middle.Lower middle.Bottom.The subtrees show events that may occur to patients during a 1-month cycle. The arrhythmia subtree. A patient who receives the implantable cardioverter defibrillator (ICD)-only regimen or the amiodarone-only regimen and has ventricular arrhythmia enters the arrhythmia subtree. If the patient survives the arrhythmia, he or she may have neurologic impairment or may become well (have no neurologic sequelae). A patient who is well continues to receive the assigned therapy (Rx) and returns to the appropriate Markov node (see ) to begin another 1-month period. The amiodarone-to-ICD ventricular tachycardia (VT) subtree. Fifty percent of patients who survive ventricular tachycardia without neurologic impairment receive an ICD; the other 50% continue to receive amiodarone. The amiodarone-to-ICD ventricular fibrillation (VF) subtree. All patients who have VF receive an ICD, as denoted by the chance node with only one branch (ICD implantation). The amiodarone toxicity subtree. This represents the events that may occur in patients in whom amiodarone toxicity occurs. A patient may have an acute side effect, withdraw from treatment, or die as a result of toxicity. Acute toxicity represents time-limited symptoms that require evaluation and management (for example, thyroid dysfunction) but not discontinuation of amiodarone therapy. Figure Legend: Copyright © American College of Physicians. All rights reserved.American College of Physicians

3. Date of download: 7/9/2016 From: Cost-Effectiveness of Implantable Cardioverter Defibrillators Relative to Amiodarone for Prevention of Sudden Cardiac Death Ann Intern Med. 1997;126(1):1-12. doi:10.7326/0003-4819-126-1-199701010-00001 Sensitivity analyses.Top.Bottom.Base-case estimates for each sensitivity analysis are indicated by arrows. Effect of the increased survival advantage produced by an implantable cardioverter defibrillator (ICD) on the cost-effectiveness of therapy with an ICD compared with amiodarone therapy. The frequency of generator replacement substantially affects marginal cost-effectiveness because the devices are expensive. Figure Legend: Copyright © American College of Physicians. All rights reserved.American College of Physicians

4. Date of download: 7/9/2016 From: Cost-Effectiveness of Implantable Cardioverter Defibrillators Relative to Amiodarone for Prevention of Sudden Cardiac Death Ann Intern Med. 1997;126(1):1-12. doi:10.7326/0003-4819-126-1-199701010-00001 Effect of cost of implantation of an implantable cardioverter defibrillator (ICD) on cost-effectiveness.The middle line shows the base-case cost estimate for ICD implantation; the top and bottom lines show how cost- effectiveness varies if implantation costs are increased or decreased by 20%. Figure Legend: Copyright © American College of Physicians. All rights reserved.American College of Physicians