Cost-effectiveness Evaluation of the 2021 US Preventive Services Task Force Recommendation for Lung Cancer Screening

Abstract

Importance: The US Preventive Services Task Force (USPSTF) issued its 2021 recommendation on lung cancer screening, which lowered the starting age for screening from 55 to 50 years and the minimum cumulative smoking exposure from 30 to 20 pack-years relative to its 2013 recommendation. Although costs are expected to increase because of the expanded screening eligibility criteria, it is unknown whether the new guidelines for lung cancer screening are cost-effective.

Objective: To evaluate the cost-effectiveness of the 2021 USPSTF recommendation for lung cancer screening compared with the 2013 recommendation and to explore the cost-effectiveness of 6 alternative screening strategies that maintained a minimum cumulative smoking exposure of 20 pack-years and an ending age for screening of 80 years but varied the starting ages for screening (50 or 55 years) and the number of years since smoking cessation (≤15, ≤20, or ≤25).

Design, setting, and participants: A comparative cost-effectiveness analysis using 4 independently developed microsimulation models that shared common inputs to assess the population-level health benefits and costs of the 2021 recommended screening strategy and 6 alternative screening strategies compared with the 2013 recommended screening strategy. The models simulated a 1960 US birth cohort. Simulated individuals entered the study at age 45 years and were followed up until death or age 90 years, corresponding to a study period from January 1, 2005, to December 31, 2050.

Exposures: Low-dose computed tomography in lung cancer screening programs with a minimum cumulative smoking exposure of 20 pack-years.

Main outcomes and measures: Incremental cost-effectiveness ratio (ICER) per quality-adjusted life-year (QALY) of the 2021 vs 2013 USPSTF lung cancer screening recommendations as well as 6 alternative screening strategies vs the 2013 USPSTF screening strategy. Strategies with a mean ICER lower than $100 000 per QALY were deemed cost-effective.

Results: The 2021 USPSTF recommendation was estimated to be cost-effective compared with the 2013 recommendation, with a mean ICER of $72 564 (range across 4 models, $59 493-$85 837) per QALY gained. The 2021 recommendation was not cost-effective compared with 6 alternative strategies that used the 20 pack-year criterion. Strategies associated with the most cost-effectiveness included those that expanded screening eligibility to include a greater number of former smokers who had not smoked for a longer duration (ie, ≤20 years and ≤25 years since smoking cessation vs ≤15 years since smoking cessation). In particular, the strategy that screened former smokers who quit within the past 25 years and began screening at age 55 years was associated with screening coverage closest to that of the 2021 USPSTF recommendation yet yielded greater cost-effectiveness, with a mean ICER of $66 533 (range across 4 models, $55 693-$80 539).

Conclusions and relevance: This economic evaluation found that the 2021 USPSTF recommendation for lung cancer screening was cost-effective; however, alternative screening strategies that maintained a minimum cumulative smoking exposure of 20 pack-years but included individuals who quit smoking within the past 25 years may be more cost-effective and warrant further evaluation.

Figure 1.. Excess Health Benefits and Costs of the 2021 vs 2013 US Preventive Services Task Force (USPSTF) Strategies for Lung Cancer Screening

Mean values across the 4 Cancer Intervention and Surveillance Modeling Network (CISNET) models. The cost-effectiveness efficiency frontier comprised lung cancer screening strategies with a minimum cumulative smoking exposure of 20 pack-years. The additional cost accrued and quality-adjusted life-years (QALYs) gained for a given screening strategy vs the 2013 USPSTF screening strategy were normalized per 100 000 persons (both ever eligible and never eligible for screening) who were alive at age 45 years. The cost-effectiveness efficiency frontier was formed by line segments connecting strategies that were not dominated by any other strategy (ie, the most effective screening strategies in terms of QALYs gained at any given cost level). A weakly dominated strategy was defined as a strategy dominated by a linear combination of 2 other strategies, and a strongly dominated strategy was defined as a strategy for which another strategy existed that yielded better health benefit at lower cost. The slope of the line segment connecting 2 strategies represents the number of QALYs gained per unit of cost; the inverse of the slope corresponds to the incremental cost-effectiveness ratio (ICER) of the 2 strategies, which represents the amount of additional cost incurred to obtain 1 additional QALY using the new vs old strategy. The labels of the screening strategies represent the following (left to right, separated by hyphens): starting age of screening (in years), ending age of screening (in years), minimum pack-years of smoking, and maximum number of years since cessation of smoking. All strategies included annual screening frequency. All health outcomes and costs were discounted at a 3% annual rate. WTP indicates willingness-to-pay. ^aThe origin of all line segments (strategy 55-80-30-15) corresponds to the 2013 USPSTF strategy, which yielded 5239 total QALYs and cost $319 192 071 per 100 000 persons alive and cancer-free at age 45 years. ^bWeakly dominated. Mean ICER per QALY gained (across 4 CISNET models) vs preceding strategy on efficiency frontier: $104 273. ^cWeakly dominated. Mean ICER per QALY gained (across 4 CISNET models) vs preceding strategy on efficiency frontier: $89 908. ^dMean ICER per QALY gained (across 4 CISNET models) vs preceding strategy on efficiency frontier: $87 115. ^eMean ICER per QALY gained (across 4 CISNET models) vs preceding strategy on efficiency frontier: $63 719. ^fMean ICER per QALY gained (across 4 CISNET models) vs preceding strategy on efficiency frontier: $68 967. ^gMean ICER per QALY gained (across 4 CISNET models) vs preceding strategy on efficiency frontier: $74 502. ^hWeakly dominated. Mean ICER per QALY gained (across 4 CISNET models) vs preceding strategy on efficiency frontier: $72 561.

Figure 2.. Univariate Sensitivity Analyses of the 2021 vs 2013 US Preventive Services Task Force Screening Strategies for Lung Cancer

The tornado diagram illustrates the change in the incremental cost-effectiveness ratio (ICER), which was defined as the cost of the 2021 US Preventive Services Task Force (USPSTF) strategy minus the cost of the 2013 USPSTF strategy divided by the difference of the quality-adjusted life-year of the 2021 USPSTF strategy minus the quality-adjusted life-year of the 2013 USPSTF strategy when important input parameters were varied for both strategies (1 strategy at a time) by 25% higher or lower than their base-case values (shown in eTable 2 and eTable 3 in the Supplement). The vertical axis (solid dark line) shows the estimated ICER for the base-case analysis. The baseline ICER was $72 564. The left column of the tornado diagram shows the input parameters in descending order of their impact for the results (eg, the ICER of the 2021 USPSTF strategy vs the 2013 USPSTF strategy was most sensitive to changes in the health utility of stage I non–small cell lung cancer [NSCLC] and the least sensitive to changes in the health utility of extended small cell lung cancer [SCLC]). LC indicates lung cancer; LDCT, low-dose computed tomography; OCD, other causes of death; and Tx, treatment.