Objectives
Based largely on evidence from the National Lung Screening Trial (NLST), the Medicare program added national coverage for low-dose CT (LDCT) lung cancer screening for heavy smokers (=30 pack-year history) age 55-77 in 2015. We previously estimated the clinical, resource, and fiscal impacts of this policy vs. not screening. The objective of this study is to extend our analysis to estimate the impacts of using the American College of Radiology’s standardized LDCT screening reporting and management system (Lung Imaging Reporting and Data System, ‘Lung-RADS’) vs. the less structured approach from the NLST. In a retrospective analysis, Lung-RADS reduced the false-positive result rate from 26.6% (in the NLST) to 12.8%. The clinical and economic impacts of this reduction have not been quantified.

Methods
We developed a simulation model to estimate the 3-year incremental outcomes of screening using Lung-RADS vs. using the NLST protocol. Outcomes reflect a Medicare population with 51.7 million members (5.8 million screening-eligible) per year. LDCT screening test characteristics were derived from the NLST. Included costs were LDCT screening, follow-up imaging, bronchoscopy/biopsy, and stage-specific treatment. The base case assumes 100% adherence to Medicare screening criteria and nodule management protocols. Monetary results are reported in 2015 USD and discounted at 3% per year.

Results
Over 3 years, a Medicare LDCT screening program using Lung-RADS (vs. the NLST protocol) is expected to result in 1.3 million fewer false-positive screening results, 27,000 fewer invasive follow-up procedures, and decreased overall expenditure of $316 million ($2 per-member per-year).

Conclusions
Using Lung-RADS to standardize LDCT screening reporting and management is expected to result in a $316 million ($2 per-member per-year) reduction in Medicare expenditure over a 3-year time horizon (vs. the NLST protocol). Our findings demonstrate that Lung-RADS can have important economic impacts in addition to reducing physical and psychological harms related to false-positive screening results.