Cost-Effectiveness of Follow-Up for Subsolid Pulmonary Nodules in High-Risk Patients

Objective: To evaluate the cost-effectiveness of a number of follow-up guidelines and variants for subsolid pulmonary nodules. Methods: We used a simulation model informed by data from the literature and the National Lung Screening Trial to simulate patients with ground-glass nodules (GGNs) detected at baseline computed tomography undergoing follow-up. The nodules were allowed to grow and develop solid components over time. We tested the guidelines generated by varying follow-up recommendations for low-risk nodules, that is, pure GGNs or those stable over time. For each guideline, we computed average US costs and quality-adjusted life-years (QALYs) gained per patient and identified the incremental cost-effectiveness ratios of those on the efficient frontier. In addition, we compared the costs and effects of the most recently released version of the Lung Computed Tomography Screening Reporting and Data System (Lung-RADS), version 1.1, with those of the previous version, 1.0. Finally, we performed sensitivity analyses of our results by varying several relevant parameters. Results: Relative to the no follow-up scenario, the follow-up guideline system that was cost-effective at a willingness-to-pay of $100,000/QALY and had the greatest QALY assigned low-risk nodules a 2-year follow-up interval and stopped follow-up after 2 years for GGNs and after 5 years for part-solid nodules; this strategy yielded an incremental cost-effectiveness ratio of $99,970. Lung-RADS version 1.1 was found to be less costly but no less effective than Lung-RADS version 1.0. These findings were essentially stable under a range of sensitivity analyses. Conclusions: Ceasing follow-up for low-risk subsolid nodules after 2 to 5 years of stability is more cost-effective than perpetual follow-up. Lung-RADS version 1.1 was cheaper but similarly effective to version 1.0.