Implantable cardioverter defibrillators (ICDs) effectively prevent sudden cardiac death, but selection of appropriate patients for implantation is complex. We evaluated whether risk stratification based on risk of sudden cardiac death alone was sufficient to predict the effectiveness and cost-effectiveness of the ICD.

Methods

We developed a Markov model to evaluate the cost-effectiveness of ICD implantation compared with empiric amiodarone treatment. The model incorporated mortality rates from sudden and nonsudden cardiac death, noncardiac death and costs for each treatment strategy. We based our model inputs on data from randomized clinical trials, registries, and meta-analyses. We assumed that the ICD reduced total mortality rates by 25%, relative to use of amiodarone.

Results

The relationship between cost-effectiveness of the ICD and the total annual cardiac mortality rate is U-shaped; cost-effectiveness becomes unfavorable at both low and high total cardiac mortality rates. If the annual total cardiac mortality rate is 12%, the cost-effectiveness of the ICD varies from $36,000 per quality-adjusted life-year (QALY) gained when the ratio of sudden cardiac death to nonsudden cardiac death is 4 to $116,000 per QALY gained when the ratio is 0.25.

Conclusions

The cost-effectiveness of ICD use relative to amiodarone depends on total cardiac mortality rates as well as the ratio of sudden to nonsudden cardiac death. Studies of candidate diagnostic tests for risk stratification should distinguish patients who die suddenly from those who die nonsuddenly, not just patients who die suddenly from those who live.

Background: Positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG) is a potentially useful but expensive test to diagnose solitary pulmonary nodules.

Objective: To evaluate the cost-effectiveness of strategies for pulmonary nodule diagnosis and to specifically compare strategies that did and did not include FDG-PET.

Design: Decision model.

Data Sources: Accuracy and complications of diagnostic tests were estimated by using meta-analysis and literature review. Modeled survival was based on data from a large tumor registry. Cost estimates were derived from Medicare reimbursement and other sources.

Target Population: All adult patients with a new, noncalcified pulmonary nodule seen on chest radiograph.

Time Horizon: Patient lifetime.

Perspective: Societal.

Intervention: 40 clinically plausible combinations of 5 diagnostic interventions, including computed tomography, FDG-PET, transthoracic needle biopsy, surgery, and watchful waiting.

Outcome Measures: Costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios.

Results of Base-Case Analysis: The cost-effectiveness of strategies depended critically on the pretest probability of malignancy. For patients with low pretest probability (26%), strategies that used FDG-PET selectively when computed tomography results were possibly malignant cost as little as $20 000 per QALY gained. For patients with high pretest probability (79%), strategies that used FDG-PET selectively when computed tomography results were benign cost as little as $16 000 per QALY gained. For patients with intermediate pretest probability (55%), FDG-PET strategies cost more than $220 000 per QALY gained because they were more costly but only marginally more effective than computed tomography-based strategies.

Results of Sensitivity Analysis: The choice of strategy also depended on the risk for surgical complications, the probability of nondiagnostic needle biopsy, the sensitivity of computed tomography, and patient preferences for time spent in watchful waiting. In probabilistic sensitivity analysis, FDG-PET strategies were cost saving or cost less than $100 000 per QALY gained in 76.7%, 24.4%, and 99.9% of computer simulations for patients with low, intermediate, and high pretest probability, respectively.

Conclusions: FDG-PET should be used selectively when pretest probability and computed tomography findings are discordant or in patients with intermediate pretest probability who are at high risk for surgical complications. In most other circumstances, computed tomography-based strategies result in similar quality-adjusted life-years and lower costs.

How successful are HIV prevention programs? Which HIV prevention programs are most cost effective? Which programs are worth expanding and which should be abandoned altogether? This book addresses the quantitative evaluation of HIV prevention programs, assessing for the first time several different quantitative methods of evaluation.

The authors of the book include behavioral scientists, biologists, economists, epidemiologists, health service researchers, operations researchers, policy makers, and statisticians. They present a wide variety of perspectives on the subject, including an overview of HIV prevention programs in developing countries, economic analyses that address questions of cost effectiveness and resource allocation, case studies such as Israel's ban on Ethiopian blood donors, and descriptions of new methodologies and problems.