Comparative cost-effectiveness of screening for lung cancer using different risk scores and thresholds: the Yorkshire Lung Screening Trial.

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)2013, Prostate Lung Colorectal and Ovarian study (PLCO)M2012 >=1.51% and Liverpool Lung Project model (LLP)v2 >=5%. A Markov model estimated a no-screening counterfactual. Scenario analyses assessed how increasing PLCOM2012 (1.51%-7%) and LLPv2 (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 (USPSTF2013), 3797 (LLPv2>=5%) and 4013 (PLCOM2012>=1.51%). PLCOM2012 yielded the largest numbers screened and LCs detected, most QALYs gained and highest incremental net monetary benefit. Raising LLPv2 and PLCOM2012 thresholds 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, PLCOM2012 thresholds 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.