For patients with bifascicular block and syncope of unknown origin, different American Heart Association guidelines give Class 2A recommendations for two treatments: the implantable loop recorder (ILR) and empiric pacemaker insertion (PM). Equipoise reflected in guidelines may contribute to uncertainty in management and inefficient resource use. The objective of this analysis is to determine the cost-effectiveness of ILR compared to PM in the management of older adults (age>50 years) with bifascicular block and syncope over two years, from the perspective of a Canadian publicly funded health care system, in the Syncope: Pacing or Recording In ThE Later Years (SPRITELY) trial.
Resource utilization data was collected throughout the trial, and unit costs were assigned (2017 Canadian dollars). Utility was measured at baseline and annually with the EQ-5D-3L. Quality adjusted life years (QALYs) were calculated as area-under-the-curve, and adjusted for baseline imbalances in utility. Confidence intervals for the incremental cost effectiveness ratio were generated with non-parametric bootstrapping.
Mean cost in participants randomized to PM was CAD 9,759 (USD 7,400), compared to CAD 13,453 (USD 10,200) in participants randomized to ILR. The ILR strategy resulted in 0.020 QALYs more than the PM strategy. The incremental cost effectiveness ratio was CAD 186,553 (95% CI: −831,950–1,191,816) (USD 141,900, 95% CI: −632,740–906,440) per additional QALY. In 1,000 bootstrapped replicates, the cost of the ILR strategy was always greater than that of the PM strategy. At the threshold of CAD 50,000 (USD 38,000) per additional QALY, the probability that the ILR strategy is the cost effective option is 0.504.
ILR costs were greater than PM costs, with little difference in QALY outcomes over two-years. Findings are generalizable to patients similar to SPRITELY participants, from the perspective of the Canadian health care system. However, practice pattern variation and payment systems inhibit generalizability to other countries. Future analysis will explore cost and QALY outcomes in countries that participated in the SPRITELY trial.