Long-term economic impacts of exome sequencing for suspected monogenic disorders: diagnosis, management, and reproductive outcomes

Purpose: To undertake the first end-to-end cost-effectiveness analysis of exome sequencing (ES) in rare disease diagnosis. 

Methods: A cohort of 80 infants who underwent ES and usual diagnostic care in parallel were used to model incremental cost and health outcomes (quality adjusted life-years, QALYs) attributable to ES diagnosis over a 20-year horizon. Three models were developed: (1) outcomes in patients only, (2) outcomes in patients and first-degree relatives as a result of cascade testing, and (3) outcomes in patients and first-degree relatives including parental reproductive outcomes.

Results: When the directly observed cost and health outcomes of the cohort participants were projected, the use of ES resulted in a gain of 7.39 QALYs and an incremental cost-effectiveness ratio (ICER) of AU$31,144.35 (i.e., cost per additional QALY gained). When cascade testing in first-degree relatives was added, cost-effectiveness increased, to a gain of 11.62 QALYs and an ICER of AU$20,839.57. When parental reproductive outcomes were added, cost-effectiveness increased again, with 36.00 QALYs gained and an ICER of AU$14,235.28.

Conclusion: Use of ES in suspected monogenic disorders becomes increasingly cost-effective as the benefits of ES data reanalysis, cascade testing in first-degree relatives, and parental reproductive outcomes are incorporated into modeling.