Cost-effectiveness analysis of genetic testing for familial long QT syndrome in symptomatic index cases

Background: Genetic testing for long QT syndrome (LQTS) has been available in a research setting for the past decade, and a commercial test has recently become available. However, the costs and effectiveness of genetic testing have not been estimated. Objectives: The purpose of this study was to conduct a cost-effectiveness analysis of genetic testing in the management of patients who have or are suspected to have familial LQTS. Methods: We examined the incremental cost-effectiveness of genetic testing compared with no genetic testing for symptomatic index cases and how this varied according to changes in assumptions and data inputs. Data were obtained from the published literature and a clinical cohort. Results: We found that genetic testing is more cost-effective than not testing for symptomatic index cases at an estimated cost of $2,500 per year of life saved. These results were generally robust, although they were sensitive to some data inputs such as the cost of testing and the mortality rate among untreated individuals with LQTS. Conclusion: A genetic test for familial LQTS is cost-effective relative to no testing, given our assumptions about the population to be tested and the relevant probabilities and costs. The primary benefit of testing is to more accurately diagnose and treat individuals based on a combination of clinical scores and test results. Future economic analyses of testing for familial LQTS should consider the potential benefits of genetic testing of broader populations, including family members.