Original Abstract
BACKGROUND: Lung cancer (LC) is the most common cause of cancer death in the UK and worldwide, but screening with low-dose CT (LDCT) reduces LC deaths. The UK National Screening Committee has recommended nationwide roll-out of LDCT screening, but the optimal risk thresholds for eligibility remain uncertain. METHODS: We conducted a cost-effectiveness analysis in the Yorkshire Lung Screening Trial (YLST) population comparing three eligibility criteria: US Preventive Services Task Force (USPSTF), Prostate Lung Colorectal and Ovarian study (PLCO)≥1.51% and Liverpool Lung Project model (LLP)≥5%. A Markov model estimated a no-screening counterfactual. Scenario analyses assessed how increasing PLCO(1.51%-7%) and LLP(5%-9%) thresholds affected LC detection, costs and quality-adjusted life years (QALYs). Payouts per detected LC were calculated using mortality and utility estimates from the literature and cost data from the trial. RESULTS: Incremental cost-effectiveness ratios (ICERs) versus no screening were £3949 (USPSTF), £3797 (LLP≥5%) and £4013 (PLCO≥1.51%). PLCOyielded the largest numbers screened and LCs detected, most QALYs gained and highest incremental net monetary benefit. Raising LLPand PLCOthresholds reduced both ICERs and QALYs gained. CONCLUSION: All three screening eligibility criteria are cost-effective according to the UK's willingness to pay threshold of £20 000/QALY. Within the range of thresholds observed in YLST, PLCOthresholds between ≥1.51% and ≥4% offered the most efficient cost-benefit trade-offs. Evidence suggests that lowering thresholds further would detect more LC cases while remaining cost-effective. These findings support the criteria implemented in YLST, but do not by themselves identify the optimal screening threshold for the wider UK population. TRIAL REGISTRATION NUMBER: ISRCTN42704678.