Variation in Model-Based Economic Evaluations of Low-Dose Computed Tomography Screening for Lung Cancer: A Methodological Review

Natural history models for lung Cancer: A scoping review

INTRODUCTION

Natural history models (NHMs) of lung cancer (LC) simulate the disease's natural progression providing a baseline for assessing the impact of interventions. NHMs have been increasingly used to inform public health policies, highlighting their utility. The objective of this scoping review was to summarize existing LC NHMs, identify their limitations, and propose a framework for future NHM development.

METHODS

We searched MEDLINE, Embase, Web of Science, and IEEE Xplore from their inception to October 5, 2023, for peer-reviewed, full-length articles with an LC NHM. Model characteristics, their applications, data sources used, and limitations were extracted and narratively synthesized.

RESULTS

From 238 publications, 69 publications were included in our review, corresponding to 22 original LC NHMs and 47 model applications. The majority of the models (n = 15, 68 %) used a microsimulation approach. NHM parameters were predominately informed by cancer registries, trial and institutional data, and literature. Model quality and performance were evaluated in 8 (36 %) models. Twenty (91 %) models included at least one carcinogenesis risk factor-primarily age, sex, and smoking history. Three (14 %) LC NHMs modeled progression in never-smokers; one (5 %) addressed recurrence. Non-tobacco smoking, nodule type, and biomarker expression were not considered in existing NHMs. Based on our findings, we proposed a framework for future LC NHM development which incorporates recurrence, nodule type differentiation, biomarker expression levels, biological factors, and non-smoking-related risk factors.

CONCLUSION

Regular updating and future research are warranted to address limitations in existing NHMs thereby ensuring relevance and accuracy of modeling approaches in the evolving LC landscape.

Economic evaluation of low-dose computed tomography for lung cancer screening among high-risk individuals - evidence from Hungary based on the HUNCHEST-II study

BACKGROUND

Lung cancer (LC) is the leading cause of cancer-related death in Hungary. Early diagnosis of LC contributes to delivering survival benefits to patients. Low-dose computer tomography (LDCT) is an imaging technology that can be used to identify smaller nodules. The aim of this study was to investigate the cost-effectiveness of introducing organised LDCT screening in Hungary among individuals aged 50 to 74 years with high-risk for developing LC using clinical effectiveness and resource utilisation inputs based on the recent HUNCHEST-II clinical trial.

METHODS

We estimated costs and outcomes in a cost-utility analysis framework over the time horizon of 30 years to compare annual and biennial screening for LC with LDCT against standard screening. The economic evaluation simulated a cohort of current and former smokers aged 50 to 74 years with a smoking exposure of at least 25 pack-years, using data from HUNCHEST-II, a multicentre study to evaluate the impact of LDCT screening on early detection of LC. Complementary data were retrieved from published studies and interviews with local experts.

RESULTS

The results of the analysis are favourable from an economic perspective: the introduction of biennial screening for LC with LDCT yielded an incremental effectiveness of 0.031 QALYs as well as an increase in costs of 306 764 HUFs over the 30-year -time horizon when compared to standard screening. The value of the base case ICER (9 908 100 HUF/QALY) of biennial screening for LC with LDCT over standard screening was below the relevant cost-effectiveness threshold. Applying an annual screening strategy using LDCT yielded even more favourable cost-effectiveness results (ICER = 7 927 455 HUF/QALY) compared to biennial screening. Notably, the cost-effectiveness of biennial screening was extendedly dominated by annual screening.

CONCLUSIONS

Along with the mature data on its effectiveness, our analysis confirms that using LDCT for LC screening among high-risk individuals is a cost-effective alternative of standard screening in Hungary. Funding a nationwide lung screening program that uses LDCT is a justified decision in economic terms; annual screening would be the optimal strategy to maximize health benefits; however in case of limited financial resources, biennial LDCT screening could offer a cost saving alternative for marginally less health gains than annual screening.

Cost-Effectiveness Analysis of Risk Factor-Based Lung Cancer Screening Program by Low-Dose Computer Tomography in Current Smokers in China

Although the effectiveness of lung cancer screening by low-dose computed tomography (LDCT) could be shown in China, there could be variation in the evidence concerning the economic impact. Our study explores the cost-effectiveness of lung cancer screening and optimizes the best definition of a high-risk population. A Markov model consisting of the natural history and post-diagnosis states was constructed to estimate the costs and quality-adjusted life years (QALYs) of LDCT screening compared with no screening. A total of 36 distinct risk factor-based screening strategies were assessed by incorporating starting ages of 40, 45, 50, 55, 60 and 65 years, stopping ages of 69, 74 and 79 years as well as smoking eligibility criteria. Screening data came from community-based mass screening with LDCT for lung cancer in Guangzhou. Compared with no screening, all screening scenarios led to incremental costs and QALYs. When the willingness-to-pay (WTP) threshold was USD37,653, three times the gross domestic product (GDP) per capita in China, six of nine strategies on the efficiency frontier may be cost-effective. Annual screening between 55 and 79 years of age for those who smoked more than 20 pack-years, which yielded an incremental cost-effectiveness ratio (ICER) of USD35,000.00 per QALY gained, was considered optimal. In sensitivity analyses, the result was stable in most cases. The trends of the results are roughly the same in scenario analyses. According to the WTP threshold of different regions, the optimal screening strategies were annual screening for those who smoked more than 20 pack-years, between 50 and 79 years of age in Zhejiang province, 55-79 years in Guangdong province and 65-74 years in Yunnan province. However, annual screening was unlikely to be cost-effective in Heilongjiang province under our modelling assumptions, indicating that tailored screening policies should be made regionally according to the local epidemiological and economic situation.

Population-Based Screening Using Low-Dose Chest Computed Tomography: A Systematic Review of Health Economic Evaluations

BACKGROUND

Chest low-dose computed tomography (LDCT) is a promising technology for population-based screening because it is non-invasive, relatively inexpensive, associated with low radiation and highly sensitive to lung cancer. To improve the cost-effectiveness of lung cancer screening, simultaneous screening for other diseases could be considered. This systematic review was conducted to analyse studies that published evidence on the cost-effectiveness of chest LDCT screening programs for different diseases.

METHODS

Scopus and PubMed were searched for English publications (1 January 2011-22 July 2022) using search terms related to screening, computed tomography and cost-effectiveness. An additional search specifically searched for the cost-effectiveness of screening for lung cancer, chronic obstructive pulmonary disease or cardiovascular disease. Included publications should present a full health economic evaluation of population screening with chest LDCT. The extracted data included the disease screened for, model type, country context of screening, inclusion of comorbidities or incidental findings, incremental costs, incremental effects and the resulting cost-effectiveness ratio amongst others. Reporting quality was assessed using the 2022 Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist.

RESULTS

The search yielded 1799 unique papers, of which 43 were included. Most papers focused on lung cancer screening (n = 40), and three were on coronary calcium scoring. Microsimulation was the most commonly applied modelling type (n = 16), followed by life table analysis (n = 10) and Markov cohort models (n = 10). Studies reflected the healthcare context of the US (n = 15), Canada (n = 4), the UK (n = 3) and 13 other countries. The reported incremental cost-effectiveness ratio ranged from US$10,000 to US$90,000/quality-adjusted life year (QALY) for lung cancer screening compared to no screening and was US$15,900/QALY-US$45,300/QALY for coronary calcium scoring compared to no screening.

DISCUSSION

Almost all health economic evaluations of LDCT screening focused on lung cancer. Literature regarding the health economic benefits of simultaneous LDCT screening for multiple diseases is absent. Most studies suggest LDCT screening is cost-effective for current and former smokers aged 55-74 with a minimum of 30 pack-years of smoking history. Consequently, more evidence on LDCT is needed to support further cost-effectiveness analyses. Preferably evidence on simultaneous screening for multiple diseases is needed, but alternatively, on single-disease screening.

REGISTRATION OF SYSTEMATIC REVIEW

Prospective Register of Ongoing Systematic Reviews registration CRD42021290228 can be accessed https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=290228 .

Lung cancer screening

Randomised controlled trials, including the National Lung Screening Trial (NLST) and the NELSON trial, have shown reduced mortality with lung cancer screening with low-dose CT compared with chest radiography or no screening. Although research has provided clarity on key issues of lung cancer screening, uncertainty remains about aspects that might be critical to optimise clinical effectiveness and cost-effectiveness. This Review brings together current evidence on lung cancer screening, including an overview of clinical trials, considerations regarding the identification of individuals who benefit from lung cancer screening, management of screen-detected findings, smoking cessation interventions, cost-effectiveness, the role of artificial intelligence and biomarkers, and current challenges, solutions, and opportunities surrounding the implementation of lung cancer screening programmes from an international perspective. Further research into risk models for patient selection, personalised screening intervals, novel biomarkers, integrated cardiovascular disease and chronic obstructive pulmonary disease assessments, smoking cessation interventions, and artificial intelligence for lung nodule detection and risk stratification are key opportunities to increase the efficiency of lung cancer screening and ensure equity of access.

Cost-Effectiveness Analyses of Lung Cancer Screening Using Low-Dose Computed Tomography: A Systematic Review Assessing Strategy Comparison and Risk Stratification

OBJECTIVES

Our first study objective was to assess the range of lung cancer screening intervals compared within cost-effectiveness analyses (CEAs) of low-dose computed tomography (LDCT) and to examine the implications for the strategies identified as optimally cost effective; the second objective was to examine if and how risk subgroup-specific policies were considered.

METHODS

PubMed, Embase and Web of Science were searched for model-based CEAs of LDCT lung screening. The retrieved studies were assessed to examine if the analyses considered sufficient strategy variation to permit incremental estimation of cost effectiveness. Regarding risk selection, we examined if analyses considered alternative risk strata in separate analyses or as alternative risk-based eligibility criteria for screening.

RESULTS

The search identified 33 eligible CEAs, 23 of which only considered one screening frequency. Of the 10 analyses considering multiple screening intervals, only 4 included intervals longer than 2 years. Within the 10 studies considering multiple intervals, the optimal policy choice would differ in 5 if biennial intervals or longer had not been considered. Nineteen studies conducted risk subgroup analyses, 12 of which assumed that subgroup-specific policies were possible and 7 of which assumed that a common screening policy applies to all those screened.

CONCLUSIONS

The comparison of multiple strategies is recognised as good practice in CEA when seeking optimal policies. Studies that do include multiple intervals indicate that screening intervals longer than 1 year can be relevant. The omission of intervals of 2 years or longer from CEAs of LDCT screening could lead to the adoption of sub-optimal policies. There also is scope for greater consideration of risk-stratified policies which tailor screening intensity to estimated disease risk. Policy makers should take care when interpreting current evidence before implementing lung screening.