Economic decision analysis model of screening for lung cancer

EarlyCDT Lung blood test for risk classification of solid pulmonary nodules: systematic review and economic evaluation

BACKGROUND

EarlyCDT Lung (Oncimmune Holdings plc, Nottingham, UK) is a blood test to assess malignancy risk in people with solid pulmonary nodules. It measures the presence of seven lung cancer-associated autoantibodies. Elevated levels of these autoantibodies may indicate malignant disease. The results of the test might be used to modify the risk of malignancy estimated by existing risk calculators, including the Brock and Herder models.

OBJECTIVES

The objectives were to determine the diagnostic accuracy, clinical effectiveness and cost-effectiveness of EarlyCDT Lung; and to develop a conceptual model and identify evidence requirements for a robust cost-effectiveness analysis.

DATA SOURCES

MEDLINE (including Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE Daily and Ovid MEDLINE), EMBASE, Cochrane Central Register of Controlled Trials, Science Citation Index, EconLit, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Health Technology Assessment database, NHS Economic Evaluation Database ( NHS EED ) and the international Health Technology Assessment database were searched on 8 March 2021.

REVIEW METHODS

A systematic review was performed of evidence on EarlyCDT Lung, including diagnostic accuracy, clinical effectiveness and cost-effectiveness. Study quality was assessed with the quality assessment of diagnostic accuracy studies-2 tool. Evidence on other components of the pulmonary nodule diagnostic pathway (computerised tomography surveillance, Brock risk, Herder risk, positron emission tomography-computerised tomography and biopsy) was also reviewed. When feasible, bivariate meta-analyses of diagnostic accuracy were performed. Clinical outcomes were synthesised narratively. A simulation study investigated the clinical impact of using EarlyCDT Lung. Additional reviews of cost-effectiveness studies evaluated (1) other diagnostic strategies for lung cancer and (2) screening approaches for lung cancer. A conceptual model was developed.

RESULTS

A total of 47 clinical publications on EarlyCDT Lung were identified, but only five cohorts (695 patients) reported diagnostic accuracy data on patients with pulmonary nodules. All cohorts were small or at high risk of bias. EarlyCDT Lung on its own was found to have poor diagnostic accuracy, with a summary sensitivity of 20.2% (95% confidence interval 10.5% to 35.5%) and specificity of 92.2% (95% confidence interval 86.2% to 95.8%). This sensitivity was substantially lower than that estimated by the manufacturer (41.3%). No evidence on the clinical impact of EarlyCDT Lung was identified. The simulation study suggested that EarlyCDT Lung might potentially have some benefit when considering intermediate risk nodules (10-70% risk) after Herder risk analysis. Two cost-effectiveness studies on EarlyCDT Lung for pulmonary nodules were identified; none was considered suitable to inform the current decision problem. The conceptualisation process identified three core components for a future cost-effectiveness assessment of EarlyCDT Lung: (1) the features of the subpopulations and relevant heterogeneity, (2) the way EarlyCDT Lung test results affect subsequent clinical management decisions and (3) how changes in these decisions can affect outcomes. All reviewed studies linked earlier diagnosis to stage progression and stage shift to final outcomes, but evidence on these components was sparse.

LIMITATIONS

The evidence on EarlyCDT Lung among patients with pulmonary nodules was very limited, preventing meta-analyses and economic analyses.

CONCLUSIONS

The evidence on EarlyCDT Lung among patients with pulmonary nodules is insufficient to draw any firm conclusions as to its diagnostic accuracy or clinical or economic value.

FUTURE WORK

Prospective cohort studies, in which EarlyCDT Lung is used among patients with identified pulmonary nodules, are required to support a future assessment of the clinical and economic value of this test. Studies should investigate the diagnostic accuracy and clinical impact of EarlyCDT Lung in combination with Brock and Herder risk assessments. A well-designed cost-effectiveness study is also required, integrating emerging relevant evidence with the recommendations in this report.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42021242248.

FUNDING

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 49. See the NIHR Journals Library website for further project information.

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.

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

OBJECTIVES

There is significant heterogeneity in the results of published model-based economic evaluations of low-dose computed tomography (LDCT) screening for lung cancer. We sought to understand and demonstrate how these models differ.

METHODS

An expansion and update of a previous systematic review (N = 19). Databases (including MEDLINE and Embase) were searched. Studies were included if strategies involving (single or multiple) LDCT screening were compared with no screening or other imaging modalities, in a population at risk of lung cancer. More detailed data extraction of studies from the previous review was conducted. Studies were critically appraised using the Consensus Health Economic Criteria list.

RESULTS

A total of 16 new studies met the inclusion criteria, giving a total of 35 studies. There are geographic and temporal differences and differences in screening intervals and eligible populations. Studies varied in the types of models used, for example, decision tree, Markov, and microsimulation models. Most conducted a cost-effectiveness analysis (using life-years gained) or cost-utility analysis. The potential for overdiagnosis was considered in many models, unlike with other potential consequences of screening. Some studies report considering lead-time bias, but fewer mention length bias. Generally, the more recent studies, involving more complex modeling, tended to meet more of the critical appraisal criteria, with notable exceptions.

CONCLUSIONS

There are many differences across the economic evaluations contributing to variation in estimates of the cost-effectiveness of LDCT screening for lung cancer. Several methodological factors and evidence needs have been highlighted that will require consideration in future economic evaluations to achieve better agreement.

Lung cancer screening: who pays? Who receives? The European perspectives

Lung cancer is the leading cause of cancer-related death worldwide, and its early detection is critical to achieving a curative treatment and to reducing mortality. Low-dose computed tomography (LDCT) is a highly sensitive technique for detecting noninvasive small lung tumors in high-risk populations. We here analyze the current status of lung cancer screening (LCS) from a European point of view. With economic burden of health care in most European countries resting on the state, it is important to reduce costs of screening and improve its effectiveness. Current cost-effectiveness analyses on LCS have indicated a favorable economic profile. The most recently published analysis reported an incremental cost-effectiveness ratio (ICER) of €3,297 per 1 life-year gained adjusted for the quality of life (QALY) and €2,944 per life-year gained, demonstrating a 90% probability of ICER being below €15,000 and a 98.1% probability of being below €25,000. Different risk models have been used to identify the target population; among these, the PLCOM2012 in particular allows for the selection of the population to be screened with high sensitivity. Risk models should also be employed to define screening intervals, which can reduce the general number of LDCT scans after the baseline round. Future perspectives of screening in a European scenario are related to the will of the policy makers to implement policy on a large scale and to improve the effectiveness of a broad screening of smoking-related disease, including cardiovascular prevention, by measuring coronary calcium score on LDCT. The employment of artificial intelligence (AI) in imaging interpretation, the use of liquid biopsies for the characterization of CT-detected undetermined nodules, and less invasive, personalized surgical treatments, will improve the effectiveness of LCS.

Favorable incremental cost-effectiveness ratio for lung cancer screening in Italy

OBJECTIVES

Lung cancer detection by low-dose computed tomographic screening reduces mortality. However, it is essential to assess cost-effectiveness. We present a cost-effectiveness analysis of screening in Italians at high risk of lung cancer, from the point of view of the Italian tax-payer.

MATERIALS AND METHODS

We used a decision model to estimate the cost-effectiveness of annual screening for 5 years in smokers (≥30 pack-years) of 55-79 years. Patients diagnosed in the COSMOS study were the screening arm; patients diagnosed and treated for lung cancer in the Lombardy Region, Italy, constituted the usual care arm. Treatment costs were extracted from our hospital database. Lung cancer survival in screened patients was adjusted for 2-year lead-time bias. Life-years and quality-adjusted life-years were estimated by stage at diagnosis, from which incremental cost-effectiveness ratios per life-year and quality-adjusted life-year gained were estimated.

RESULTS

Base-case incremental cost-effectiveness ratios were 3297 and 2944 euro per quality-adjusted life-year and life-year gained, respectively. Deterministic sensitivity analysis indicated that these values were particularly sensitive to lung cancer prevalence, screening sensitivity and specificity, screening cost, and treatment costs for stage I and IV disease. From the probabilistic sensitivity analysis incremental cost-effectiveness ratios had a 98 % probability of being <25,000 euro (widely-accepted threshold) and a 55 % probability of being <5000 euro.

CONCLUSIONS

Low-dose computed tomographic screening is associated with an incremental cost of 2944 euro per life-year gained in high risk population, implying that screening can be introduced in Italy at contained cost, saving the lives of many lung cancer patients.

Low-dose computed tomography for lung cancer screening in high-risk populations: a systematic review and economic evaluation

BACKGROUND

Diagnosis of lung cancer frequently occurs in its later stages. Low-dose computed tomography (LDCT) could detect lung cancer early.

OBJECTIVES

To estimate the clinical effectiveness and cost-effectiveness of LDCT lung cancer screening in high-risk populations.

DATA SOURCES

Bibliographic sources included MEDLINE, EMBASE, Web of Science and The Cochrane Library.

METHODS

Clinical effectiveness - a systematic review of randomised controlled trials (RCTs) comparing LDCT screening programmes with usual care (no screening) or other imaging screening programmes [such as chest X-ray (CXR)] was conducted. Bibliographic sources included MEDLINE, EMBASE, Web of Science and The Cochrane Library. Meta-analyses, including network meta-analyses, were performed. Cost-effectiveness - an independent economic model employing discrete event simulation and using a natural history model calibrated to results from a large RCT was developed. There were 12 different population eligibility criteria and four intervention frequencies [(1) single screen, (2) triple screen, (3) annual screening and (4) biennial screening] and a no-screening control arm.

RESULTS

Clinical effectiveness - 12 RCTs were included, four of which currently contribute evidence on mortality. Meta-analysis of these demonstrated that LDCT, with ≤ 9.80 years of follow-up, was associated with a non-statistically significant decrease in lung cancer mortality (pooled relative risk 0.94, 95% confidence interval 0.74 to 1.19). The findings also showed that LDCT screening demonstrated a non-statistically significant increase in all-cause mortality. Given the considerable heterogeneity detected between studies for both outcomes, the results should be treated with caution. Network meta-analysis, including six RCTs, was performed to assess the relative clinical effectiveness of LDCT, CXR and usual care. The results showed that LDCT was ranked as the best screening strategy in terms of lung cancer mortality reduction. CXR had a 99.7% probability of being the worst intervention and usual care was ranked second. Cost-effectiveness - screening programmes are predicted to be more effective than no screening, reduce lung cancer mortality and result in more lung cancer diagnoses. Screening programmes also increase costs. Screening for lung cancer is unlikely to be cost-effective at a threshold of £20,000/quality-adjusted life-year (QALY), but may be cost-effective at a threshold of £30,000/QALY. The incremental cost-effectiveness ratio for a single screen in smokers aged 60-75 years with at least a 3% risk of lung cancer is £28,169 per QALY. Sensitivity and scenario analyses were conducted. Screening was only cost-effective at a threshold of £20,000/QALY in only a minority of analyses.

LIMITATIONS

Clinical effectiveness - the largest of the included RCTs compared LDCT with CXR screening rather than no screening. Cost-effectiveness - a representative cost to the NHS of lung cancer has not been recently estimated according to key variables such as stage at diagnosis. Certain costs associated with running a screening programme have not been included.

CONCLUSIONS

LDCT screening may be clinically effective in reducing lung cancer mortality, but there is considerable uncertainty. There is evidence that a single round of screening could be considered cost-effective at conventional thresholds, but there is significant uncertainty about the effect on costs and the magnitude of benefits.

FUTURE WORK

Clinical effectiveness and cost-effectiveness estimates should be updated with the anticipated results from several ongoing RCTs [particularly the NEderlands Leuvens Longkanker Screenings ONderzoek (NELSON) screening trial].

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016048530.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Collaborative Modeling: Experience of the U.S. Preventive Services Task Force

Models can be valuable tools to address uncertainty, trade-offs, and preferences when trying to understand the effects of interventions. Availability of results from two or more independently developed models that examine the same question (comparative modeling) allows systematic exploration of differences between models and the effect of these differences on model findings. Guideline groups sometimes commission comparative modeling to support their recommendation process. In this commissioned collaborative modeling, modelers work with the people who are developing a recommendation or policy not only to define the questions to be addressed but ideally, work side-by-side with each other and with systematic reviewers to standardize selected inputs and incorporate selected common assumptions. This paper describes the use of commissioned collaborative modeling by the U.S. Preventive Services Task Force (USPSTF), highlighting the general challenges and opportunities encountered and specific challenges for some topics. It delineates other approaches to use modeling to support evidence-based recommendations and the many strengths of collaborative modeling compared with other approaches. Unlike systematic reviews prepared for the USPSTF, the commissioned collaborative modeling reports used by the USPSTF in making recommendations about screening have not been required to follow a common format, sometimes making it challenging to understand key model features. This paper presents a checklist developed to critically appraise commissioned collaborative modeling reports about cancer screening topics prepared for the USPSTF.

Herbal medicines and chemotherapy induced peripheral neuropathy (CIPN): A critical literature review

BACKGROUND

Chemotherapy induced peripheral neuropathy [CIPN] is a common significant and debilitating side-effect resulting from the administration of neurotoxic chemotherapeutic agents. These pharmaco-chemotherapeutics can include taxanes, vinca alkaloids, platinum analogues, and others. Moderate to severe CIPN significantly decreases the quality of life and physical abilities of cancer patients and current pharmacotherapy for CIPN e.g. Amifostine, and antidepressants have had limited efficacy and may themselves induce adverse side-effects.

METHODS

To determine the potential use of herbal medicines as adjuvants in cancer treatments, a critical literature review was conducted by electronic and manual search on nine databases. These include PubMed, the Cochrane Library, Science Direct, Scopus, EMBASE, MEDLINE, Google Scholar, and two Chinese databases CNKI and CINAHL. Thirty-four studies were selected from 5614 studies assessed and comprising animal studies, case reports, retrospective studies, and minimal randomized clinical trials investigating the anti-CIPN effect of herbal medicines as the adjuvant intervention in patients administered chemotherapy. The thirty-four studies were assessed on methodological quality and limitations identified.

RESULTS

Studies were mixed in their recommendations for herbal medicines as an adjuvant treatment for CIPN.

CONCLUSION

Currently no agent has shown solid beneficial evidence to be recommended for the treatment or prophylaxis of CIPN. Given that the number of cancer survivors is increasing, the long-term side effects of cancer treatment, is of major importance.

Cost-Effectiveness Analyses of Lung Cancer Screening Strategies Using Low-Dose Computed Tomography: a Systematic Review

BACKGROUND

Lung cancer screening with low-dose computed tomography (LDCT) has been shown to deliver appreciable reductions in mortality in high-risk patients. However, in an era of constrained medical resources, the cost-effectiveness of such a program needs to be demonstrated.

OBJECTIVE

The aim of this study was to systematically review the literature analyzing the cost-effectiveness of lung cancer screening using LDCT.

METHODS

We searched MEDLINE, EMBASE, EBM Reviews-Health Technology Assessment, the National Health Service Economic Evaluation Database (NHS-EED), and the Cochrane Database of Systematic Reviews. Due to technological progress in CT, we limited our search to studies published between January 2000 and December 2014. Our search returned 393 unique results. After removing studies that did not meet our inclusion criteria, 13 studies remained. Costs are presented in 2014 US dollars (US$).

RESULTS

The results from the economic evaluations identified in this review were varied. All identified studies reported outcomes using either additional survival (life-years gained) or quality-adjusted life-years (QALYs gained). Results ranged from US$18,452 to US$66,480 per LYG and US$27,756 to US$243,077 per QALY gained for repeated screening. The results of cost-effectiveness analyses were sensitive to several key model parameters, including the prevalence of lung cancer, cost of LDCT for screening, the proportion of lung cancer detected as localized disease, lead time bias, and, if included, the characteristics of a smoking cessation program.

CONCLUSIONS

The cost-effectiveness of a lung cancer screening program using LDCT remains to be conclusively resolved. It is expected that its cost-effectiveness will largely depend on identifying an appropriate group of high-risk subjects.

Implementing lung cancer screening in the real world: opportunity, challenges and solutions

The World Health Organization estimates that, in 2012, there were 1,589,925 deaths from lung cancer worldwide. Screening for lung cancer with low-dose computed tomography (LDCT) has the potential to significantly alter this statistic, by identifying lung cancers in earlier stages, enabling curative treatment. Challenges remain, however, in replicating the 20% mortality benefit demonstrated by the National Lung Screening Trial (NLST), in populations outside the confines of a research trial, not only in the US but around the world. We review the history of lung cancer screening, the current evidence for LDCT screening, and the key elements needed for a successful screening program.

Cost-effectiveness of screening for lung cancer with low-dose computed tomography: a systematic literature review

BACKGROUND

On 31 December 2013, the US Preventive Services Task Force rated low-dose computed tomography (LDCT) for lung cancer screening as level 'B' recommendation. Yet, lung cancer screening implementation remains controversial, particularly when considering its cost-effectiveness. The aim of this work is to investigate the cost-effectiveness of LDCT screening program for lung cancer by performing a systematic literature review.

METHODS

We reviewed the published economic evaluations of LDCT in lung cancer screening. MEDLINE, ISI Web of Science and Cochrane databases were searched for literature retrieval up to 31 March 2015. Inclusion criteria included: studies reporting an original full economic evaluation; reports presenting the outcomes as Quality-Adjusted Life Years (QALYs) gained or as Life Years Gained.

RESULTS

Nine economic evaluations met the inclusion criteria. All the cost-effectiveness analyses included high risk populations for lung cancer and compared the use of annual LDCT screening with no screening. Seven studies reported an incremental cost-effectiveness ratio below the threshold of US$ 100 000 per QALY gained.

CONCLUSIONS

Cost-effectiveness of LDCT screening for lung cancer is an highly debatable issue. Currently available economic evaluations suggest the cost-effectiveness of LDCT for lung cancer screening compared with no screening and indicate that the implementation of LDCT should be considered when planning a national lung cancer screening program. Additional economic evaluations, especially from a societal perspective and in an EU-setting, are needed.

Is chest X-ray screening for lung cancer in smokers cost-effective? Evidence from a population-based study in Italy

Background

After implementation of the PREDICA annual chest X-ray (CXR) screening program in smokers in the general practice setting of Varese-Italy a significant reduction in lung cancer-specific mortality (18 %) was observed. The objective of this study covering July 1997 through December 2006 was to estimate the cost-effectiveness of this intervention.

Methods

We examined detailed information on lung cancer (LC) cases that occurred among smokers invited to be screened in the PREDICA study (Invitation-to-screening Group, n = 5815 subjects) to estimate costs and quality-adjusted life-years (QALYs) from LC diagnosis until death. The control group consisted of 156 screening-eligible smokers from the same area, uninvited and unscreened, who developed LC and were treated by usual care. We calculated the incremental net monetary benefit (INMB) by comparing LC management in screening participants (n = 1244 subjects) and in the Invitation-to-screening group versus control group.

Results

The average number of QALYs since LC diagnosis was 1.7, 1.49 and 1.07, respectively, in screening participants, the invitation-to-screening group, and the control group. The average total cost (screening + management) per LC case was higher in screening participants (€17,516) and the Invitation-to-screening Group (€16,167) than in the control group (€15,503). Assuming a maximum willingness to pay of €30,000/QALY, we found that the intervention was cost-effective with high probability: 79 % for screening participation (screening participants vs. control group) and 95 % for invitation-to-screening (invitation-to-screening group vs. control group).

Conclusions

Based on the PREDICA study, annual CXR screening of high-risk smokers in a general practice setting has high probability of being cost-effective with a maximum willingness to pay of €30,000/QALY.

Lung cancer screening: Computed tomography or chest radiographs?

Worldwide, lung cancer is the leading cause of mortality due to malignancy. The vast majority of cases of lung cancer are smoking related and the most effective way of reducing lung cancer incidence and mortality is by smoking cessation. In the Western world, smoking cessation policies have met with limited success. The other major means of reducing lung cancer deaths is to diagnose cases at an earlier more treatable stage employing screening programmes using chest radiographs or low dose computed tomography. In many countries smoking is still on the increase, and the sheer scale of the problem limits the affordability of such screening programmes. This short review article will evaluate the current evidence and potential areas of research which may benefit policy making across the world.

Lung cancer screening overdiagnosis: reports of overdiagnosis in screening for lung cancer are grossly exaggerated

The National Lung Cancer Screening Trial (NLST) demonstrated a mortality reduction benefit associated with low-dose computed tomography (LDCT) screening for lung cancer. There has been considerable debate regarding the benefits and harms of LDCT lung cancer screening, including the challenges related to its practical implementation. One of the controversies regards overdiagnosis, which conceptually denotes diagnosing a cancer that, either because of its indolent, low-aggressiveness biologic behavior or because of limited life expectancy, is unlikely to result in significant morbidity during the patient's remainder lifetime. In theory, diagnosing and treating these cancers offer no measurable benefit while incurring costs and risks. Therefore, if a screening test detects a substantial number of overdiagnosed cancers, it is less likely to be effective. It has been argued that LDCT screening for lung cancer results in an unacceptably high rate of overdiagnosis. This article aims to defend the opposite stance. Overdiagnosis does exist and to a certain extent is inherent to any cancer-screening test. Nonetheless, the concept is less dualistic and more nuanced than it has been suggested. Furthermore, the average estimates of overdiagnosis in LDCT lung cancer screening based on the totality of published data are likely much lower than the highest published estimates, if a careful definition of a positive screening test reflecting our current understanding of lung cancer biology is utilized. This article presents evidence on why reports of overdiagnosis in lung cancer screening have been exaggerated.

Current estimate of costs of lung cancer screening in the United States

The United States Preventive Services Task Force recently endorsed the use of low-dose computed tomography for lung cancer screening in high-risk patients because of the potential to reduce deaths. Before implementation on a national level, it will be important to ensure that a safe, high-quality, and accessible service can be adequately provided. It will also be important to make sure that screening is cost-effective. This article summarizes the published analyses of lung cancer screening cost, provides a contemporary estimation of the annual cost of screening in the United States, and identifies areas for improvement in the future.

Controversies in lung cancer screening

There remains an extensive debate over lung cancer screening, with lobbying for and against screening for very compelling reasons. The National Lung Screening Trial, International Early Lung Cancer Program, and other major screening studies favor screening with low-dose CT scans and have shown a reduction in lung cancer--specific mortality. The increasing incidence of lung cancer and the dismal survival rate for advanced disease despite improved multimodality therapy have sparked an interest in the implementation of national lung cancer screening. Concerns over imaging workflow, radiation dose, management of small nodules, overdiagnosis bias, lead-time and length-time bias, emerging new technologies, and cost-effectiveness continue to be debated. The authors address each of these issues as they relate to radiologic practice.

Cost-effectiveness of baseline low-dose computed tomography screening for lung cancer: the Israeli experience

OBJECTIVE

Reduced mortality with low-dose computed tomography (LDCT) lung cancer screening was demonstrated in a large randomized controlled study of high-risk individuals. Cost-effectiveness must be assessed before routine LDCT screening is considered. We aimed to evaluate the cost-effectiveness of LDCT lung cancer screening in Israel.

METHODS

A decision analytic framework was used to evaluate the decision to screen or not screen from the health system perspective. The screening arm included 842 moderate-to-heavy smokers aged 45 years or older, screened at Hadassah-Hebrew University Medical Center from 1998 to 2004. In the usual-care arm, stage distribution and stage-specific life expectancy were obtained from the Israel National Cancer Registry data for 1994 to 2006. Lifetime stage-specific costs were estimated from medical records of patients diagnosed and treated at Hadassah Medical Center in the period 2003 to 2004. The analysis considered possible biases-lead time, overdiagnosis, and self-selection. Cost per quality-adjusted-life-year (QALY) gained by screening was estimated.

RESULTS

Base-case incremental cost per QALY gained was $1464 (2011 prices). Extensive sensitivity analysis affirmed the low cost per QALY gained. The cost per QALY gained is lower than $10,000 with probability 0.937 and is lower than $20,000 with probability 0.978.

CONCLUSIONS

Our analysis suggests that baseline LDCT lung cancer screening in Israel presents a good value for the money and should be considered for inclusion in the National List of Health Services financed publicly.

A cost-utility analysis of lung cancer screening and the additional benefits of incorporating smoking cessation interventions

BACKGROUND

A 2011 report from the National Lung Screening Trial indicates that three annual low-dose computed tomography (LDCT) screenings for lung cancer reduced lung cancer mortality by 20% compared to chest X-ray among older individuals at high risk for lung cancer. Discussion has shifted from clinical proof to financial feasibility. The goal of this study was to determine whether LDCT screening for lung cancer in a commercially-insured population (aged 50-64) at high risk for lung cancer is cost-effective and to quantify the additional benefits of incorporating smoking cessation interventions in a lung cancer screening program.

METHODS AND FINDINGS

The current study builds upon a previous simulation model to estimate the cost-utility of annual, repeated LDCT screenings over 15 years in a high risk hypothetical cohort of 18 million adults between age 50 and 64 with 30+ pack-years of smoking history. In the base case, the lung cancer screening intervention cost $27.8 billion over 15 years and yielded 985,284 quality-adjusted life years (QALYs) gained for a cost-utility ratio of $28,240 per QALY gained. Adding smoking cessation to these annual screenings resulted in increases in both the costs and QALYs saved, reflected in cost-utility ratios ranging from $16,198 per QALY gained to $23,185 per QALY gained. Annual LDCT lung cancer screening in this high risk population remained cost-effective across all sensitivity analyses.

CONCLUSIONS

The findings of this study indicate that repeat annual lung cancer screening in a high risk cohort of adults aged 50-64 is highly cost-effective. Offering smoking cessation interventions with the annual screening program improved the cost-effectiveness of lung cancer screening between 20% and 45%. The cost-utility ratios estimated in this study were in line with other accepted cancer screening interventions and support inclusion of annual LDCT screening for lung cancer in a high risk population in clinical recommendations.

Dynamic microsimulation models for health outcomes: a review

BACKGROUND

Microsimulation models (MSMs) for health outcomes simulate individual event histories associated with key components of a disease process; these simulated life histories can be aggregated to estimate population-level effects of treatment on disease outcomes and the comparative effectiveness of treatments. Although MSMs are used to address a wide range of research questions, methodological improvements in MSM approaches have been slowed by the lack of communication among modelers. In addition, there are few resources to guide individuals who may wish to use MSM projections to inform decisions.

METHODS

. This article presents an overview of microsimulation modeling, focusing on the development and application of MSMs for health policy questions. The authors discuss MSM goals, overall components of MSMs, methods for selecting MSM parameters to reproduce observed or expected results (calibration), methods for MSM checking (validation), and issues related to reporting and interpreting MSM findings(sensitivity analyses, reporting of variability, and model transparency).

CONCLUSIONS

. MSMs are increasingly being used to provide information to guide health policy decisions. This increased use brings with it the need for both better understanding of MSMs by policy researchers, and continued improvement in methods for developing and applying MSMs.

Economic evaluation in radiology: reviewing the literature and examples in oncology

RATIONALE AND OBJECTIVES

To review US health care trends related to medical imaging utilization and costs as well as to present standard methods for conducting economic evaluation for health care interventions and medical imaging specifically.

MATERIALS AND METHODS

A review of the medical literature was performed to assess health policy and health technology assessment trends, expenditures, and cost-effectiveness analysis (CEA) related to medical imaging. Standard approaches to conducting economic evaluation and cost-effectiveness analysis were reviewed and summarized. Examples of CEA evidence related to imaging in select oncology conditions were presented.

RESULTS

Several high-quality methodology publications have provided guidance for conducting economic evaluation and CEA in radiology. There is variability in the quality of CEA models and their dissemination. However, there are numerous methodologically sound cost-effectiveness analyses for radiology procedures, and the evidence base of CEA studies for medical imaging continues to increase. Advanced imaging approaches for diagnosing and staging oncology conditions have the potential to provide cost-effective care when used in appropriate patient subpopulations.

CONCLUSIONS

Additional rigorous comparative effectiveness studies for advanced imaging, including cost-effectiveness analyses, can provide useful information to policy makers and health care providers on the relative effects and costs associated with diagnostic alternatives.

Cost-effectiveness of early colonoscopy surveillance after cancer resection

BACKGROUND

Short-interval surveillance colonoscopy at 1 year has been recently recommended following curative-intent surgery for colorectal cancer. However, the efficacy and cost-effectiveness of this endoscopic strategy is largely unknown.

AIM

To assess the clinical and economic impact of early surveillance post-surgical colonoscopy at 1 year in relation to the detection of metachronous colorectal cancer.

METHODS

A decision analysis model was constructed in order to compare a strategy of 1-year endoscopic surveillance versus no early endoscopy following surgical resection for colorectal cancer. A 2-year cancer upstaging was modelled in order to simulate cancer progression in patients with metachronous colorectal cancer who were not referred to early endoscopy. Endoscopic prevalence of metachronous colorectal cancer was estimated from a previous pooled data analysis based on systematic review of the literature. Costs of colonoscopy and cancer care were estimated from Medicare reimbursement data. Outcome measures were the number of early colonoscopies needed to detect one case of cancer or to prevent one cancer-related death and the incremental cost-effectiveness ratio.

RESULTS

The number of early 1-year colonoscopies needed to detect one colorectal cancer and to prevent one colorectal cancer-related death was 143 and 926, respectively. The incremental cost-effectiveness ratio of the early 1-year colonoscopy as compared to a policy of not performing it was $40,313 per life-year gained. The incremental cost-effectiveness ratio of performing early surveillance colonoscopy was sensitive to the changes in cancer prevalence. However, only a reduction from the baseline value of 0.7% to 0.19% was associated with an incremental cost-effectiveness ratio higher than $150,000. Other assumptions about cancer upstaging, initial distribution of cancer, and costs had a lesser influence on incremental cost-effectiveness ratio differences.

CONCLUSIONS

Our study shows that the recently recommended short-interval 1-year surveillance colonoscopy following colorectal cancer resection is a clinically efficient and cost-effective strategy in terms of cancer detection and cancer-specific death prevention.

Cost of a 5-year lung cancer survivor: symptomatic tumour identification vs proactive computed tomography screening

Background:

Our objective was to analyse the cost effectiveness of computed tomography (CT) screening for lung cancer in terms of the cost per long-term survivor, which has not been evaluated to date.

Methods:

Estimations were computed based on data from the Surveillance, Epidemiology, and End Results registries covering years 1999–2003. The design framework of our model allowed for the incorporation of multiple values taken from the epidemiological and clinical literature to be utilised for cost inputs, scope of patients screened, diagnostic staging, and survival percentages applied separately to two cohorts: age 40–79 and 60–79 years. This enabled the analysis of over 1400 scenarios, each containing a unique set of input values, for which the estimated cost per 5-year survivor (CP5YS) was compared between the symptom-detected and proactive screening approaches.

Results:

Estimated CP5YS were higher for the symptom-detected approach in all 729 scenarios analysed for the cohort ages 60–79 years, ranging from approximately $5800 to $116 700 increased cost per 5-year survivor (CP5YS). For the cohort ages 40–79 years, 75% of the 729 scenarios analysed showed increased CP5YS for the symptom-detected approach ranging from $5700 to $110 000 increased CP5YS. Total costs and total 5-year survivors were higher for the proactive screening method for all scenarios analysed across both cohorts with increases ranging from 50–256% and 98–309%, respectively.

Conclusion:

The predicted increase in long-term survival with CT screening and the potential for better utilisation of health-care dollars in terms of CP5YS, particularly when screening patients over the age of 60 years, are critically important considerations in directing effective future lung cancer management strategy.

Cost-effectiveness of upper gastrointestinal endoscopy according to the appropriateness of the indication

OBJECTIVE

Application of appropriate indications for upper endoscopy (EGD) should conserve limited endoscopic resources. The cost-effectiveness of current guidelines for the detection of gastro-oesophageal cancer is unknown. The aim of this study was to assess the clinical and economic impact of ASGE and EPAGE guidelines in selecting patients referred for upper endoscopy relative to the detection of gastro-oesophageal cancer.

MATERIAL AND METHODS

A decision analysis model was constructed to compare a strategy of not referring patients for EGD (with either an appropriate or inappropriate indication) with a policy of carrying out the requested EGD. Cancer prevalence in appropriate and inappropriate EGDs was estimated using a systematic review of the literature. Costs of EGD and cancer care were estimated from Medicare reimbursement data.

RESULTS

The number of appropriate and inappropriate EGDs required to detect one case of cancer was 41 and 753, respectively, and to prevent one gastro-oesophageal cancer-related death the numbers were 571 and 11,111, respectively. The incremental cost-effectiveness ratios of appropriate and inappropriate EGDs as compared to a policy of not referring patients for endoscopy were $16,577 and $301,203, respectively, per life-year gained.

CONCLUSIONS

For inappropriate EGD, the very low likelihood of cancer and the relatively high costs associated with this procedure argue against endoscopic referral.

Cost-effectiveness of early one-year colonoscopy surveillance after polypectomy

PURPOSE

Some colorectal cancers have been unexpectedly diagnosed within one year after polypectomy in high-quality trials. The purpose of this study was to assess the clinical and economic impact of early surveillance colonoscopy one year after polypectomy in relation to detection of colorectal cancer.

METHODS

A decision analysis model was constructed to compare strategies of performing or not performing one-year endoscopic surveillance in 60-year-old patients who underwent an initial endoscopic polypectomy. Outcome measures included the number of early colonoscopies needed to detect one case of cancer and to prevent one cancer-related death and the incremental cost-effectiveness ratio.

RESULTS

The number of early one-year colonoscopies needed to detect one cancer and to prevent one cancer-related death was 354 and 1,437, respectively. The incremental cost-effectiveness ratio of performing early one-year colonoscopy as compared with not performing it was $66,136 per life-year gained.

CONCLUSIONS

Current guidelines for postpolypectomy surveillance are relatively inefficient in excluding a clinically meaningful colorectal cancer risk at one year after polypectomy.

Impact of whole-body CT screening on the cost-effectiveness of CT colonography

PURPOSE

To analyze the impact of adding computed tomographic (CT) imaging of the chest on the clinical effectiveness and cost-effectiveness of CT colonography to determine whether performing CT colonography and whole-body CT is a more clinically and cost-effective strategy than CT colonography alone when screening average-risk subjects.

MATERIALS AND METHODS

A Markov model simulated the occurrence of colorectal neoplasia, extracolonic abominal-pelvic malignancy, lung cancer, coronary artery disease (CAD), and abdominal aortic aneurysm (AAA) in a cohort of 100,000 U.S. subjects aged 50 to 100 years. Cost-effectiveness of CT colonography and whole-body CT was compared with that of CT colonography alone; each test was assumed to be repeated every 10 years between ages of 50 and 80 years.

RESULTS

Performing CT colonography and whole-body CT was more effective and costly than was CT colonography alone. The addition of chest CT was associated with a 22% increase in efficacy (life-years gained: 14,662 vs 11,990) and with a 48% increase in cost per person ($13,605 vs $9,223). Both strategies were cost effective as compared with no screening, with an incremental cost-effectiveness ratio (ICER) of $17,672 (CT colonography alone) and $44,337 (CT colonography and whole-body CT), respectively, but performing CT colonography and whole-body CT was not a cost-effective option when compared with CT colonography alone (ICER, $164,020). This was mainly a result of the high cost of false-positive follow-up for CAD and to the poor efficacy of lung cancer screening. Expected value of perfect information was $520 per patient.

CONCLUSION

The addition of chest CT to CT colonography does not appear to be a cost-effective alternative. Further research is needed before whole-body CT can be recommended in clinical practice.

The value of positron emission tomography in patients with non-small cell lung cancer

BACKGROUND

Pre-operative assessment of non-small cell lung cancer (NSCLC) is a major application of positron emission tomography (FDG-PET). Despite substantial evidence of diagnostic accuracy, relatively little attention has been paid to its effects on patient outcomes. This paper addresses this by extending an existing decision model to include patient-elicited utilities.

PATIENTS AND METHODS

A decision-tree model of the effect of FDG-PET on pre-operative staging was converted to a Markov model. Utilities for futile and appropriate thoracotomy were elicited from 75 patients undergoing staging investigation for NSCLC. The decision model was then used to estimate the expected value of perfect information (EVPI) associated with three sources of uncertainty-the accuracy of PET, the accuracy of CT and the patient related utility of a futile thoracotomy.

RESULTS

The model confirmed the apparent cost-effectiveness of FDG-PET and indicated that the EVPI associated with the utility of futile thoracotomy considerably exceeds that associated with measures of accuracy.

CONCLUSION

The study highlights the importance of patient related utilities in assessing the cost-effectiveness of diagnostic technologies. In the specific case of PET for pre-operative staging of NSCLC, future research effort should focus on such elicitation, rather than further refinement of accuracy estimates.

Clinical management of small (6- to 9-mm) polyps detected at screening CT colonography: a cost-effectiveness analysis

OBJECTIVE

The primary aim of this model analysis was to compare the clinical and economic impacts of immediate polypectomy versus 3-year CT colonography (CTC) surveillance for small (6- to 9-mm) polyps detected at CTC screening.

MATERIALS AND METHODS

A decision analysis model was constructed incorporating the expected advanced neoplasia prevalence, frequency of measurable growth, colorectal cancer (CRC) prevalence and risk, CTC performance, and costs related to CRC screening and treatment. CRC risk was assumed to be independent of advanced adenoma size, which intentionally overestimates the risk related to small polyps. Clinical effectiveness and costs for 3-year CTC surveillance versus immediate colonoscopic polypectomy were compared for a concentrated cohort of patients with 6- to 9-mm polyps. For the CTC surveillance strategy, only cases with measurable growth (> or = 1 mm) at follow-up CTC were referred for polypectomy.

RESULTS

Without any intervention, the estimated 5-year CRC death rate from 6- to 9-mm polyps in this concentrated cohort was 0.08%, which is a sevenfold decrease over the 0.56% CRC risk for the general unselected screening population. The death rate was further reduced to 0.03% with the CTC surveillance strategy and to 0.02% with immediate colonoscopy referral. However, for each additional cancer-related death prevented with immediate polypectomy versus CTC follow-up, 9,977 colonoscopy referrals would be needed, resulting in 10 additional perforations and an incremental cost-effectiveness ratio of $372,853.

CONCLUSION

For patients with small (6- to 9-mm) polyps detected at CTC screening, the exclusion of large polyps (> or = 10 mm) already confers a very low risk of CRC. The high costs, additional complications, and relatively low incremental yield associated with immediate polypectomy of 6- to 9-mm polyps support the practice of 3-year CTC surveillance, which allows for selective noninvasive identification of small polyps at risk.

Cost effectiveness of colonoscopy, based on the appropriateness of an indication

BACKGROUND & AIMS

Determination of the appropriateness of an indication for colonoscopy has been advanced as a means to help rationalize the use of endoscopic resources. However, the efficacy and cost effectiveness of the current guidelines used to select patients for colonoscopy are largely unknown. The goal of this study was to assess the clinical and economic impact of American Society for Gastrointestinal Endoscopy and the European Panel on the appropriateness of Gastrointestinal Endoscopy appropriateness guidelines in selecting patients who are referred for colonoscopy, in relation to colorectal cancer (CRC) detection.

METHODS

A decision-analysis model was constructed to compare colonoscopy strategies for "appropriate" indications with those for which colonoscopy is deemed "inappropriate" or "generally not indicated." A 50% cancer upstaging was modeled to simulate cancer progression for patients not referred for colonoscopy. CRC prevalence was estimated using a pooled data analysis based on a systematic review of the literature. Costs of colonoscopy and cancer care were estimated from Medicare reimbursement data. The number of colonoscopies needed to detect one case of cancer and to prevent one cancer-related death and incremental cost-effectiveness ratios (ICER), according to appropriateness categories, were computed in a simulated population of patients that were 60 years of age and referred for colonoscopy.

RESULTS

The numbers of appropriate and inappropriate colonoscopies that needed to be performed to detect one patient with cancer were 18 and 93, respectively. Similarly, 115 and 617 colonoscopies would be needed, respectively, to prevent one CRC-related death. The ICER for appropriate and inappropriate colonoscopies, compared with a policy of not referring patients to colonoscopy, was $6154 and $31,807 per life-year gained, respectively. In a sensitivity analysis, only a reduction from the baseline value of 1.1% to 0.2% was associated with an ICER for inappropriate colonoscopy higher than $150,000.

CONCLUSIONS

Current guidelines regarding the appropriateness of colonoscopy are relatively inefficient in excluding a clinically meaningful CRC risk for patients in whom colonoscopy is generally not indicated, raising serious concerns about their applicability to clinical practice.

Estimating long-term effectiveness of lung cancer screening in the Mayo CT screening study

PURPOSE

To use individual-level data provided from the single-arm study of helical computed tomographic (CT) screening at the Mayo Clinic (Rochester, Minn) to estimate the long-term effectiveness of screening in Mayo study participants and to compare estimates from an existing lung cancer simulation model with estimates from a different modeling approach that used the same data.

MATERIALS AND METHODS

The study was approved by institutional review boards and was HIPAA compliant. Deidentified individual-level data from participants (1520 current or former smokers aged 50-85 years) in the Mayo Clinic helical CT screening study were used to populate the Lung Cancer Policy Model, a comprehensive microsimulation model of lung cancer development, screening findings, treatment results, and long-term outcomes. The model predicted diagnosed cases of lung cancer and deaths per simulated study arm (five annual screening examinations vs no screening). Main outcome measures were predicted changes in lung cancer-specific and all-cause mortality as functions of follow-up time after simulated enrollment and randomization.

RESULTS

At 6-year follow-up, the screening arm had an estimated 37% relative increase in lung cancer detection, compared with the control arm. At 15-year follow-up, five annual screening examinations yielded a 9% relative increase in lung cancer detection. The relative reduction in cumulative lung cancer-specific mortality from five annual screening examinations was 28% at 6-year follow-up (15% at 15 years). The relative reduction in cumulative all-cause mortality from five annual screening examinations was 4% at 6-year follow-up (2% at 15 years).

CONCLUSION

Screening may reduce lung cancer-specific mortality but may offer a smaller reduction in overall mortality because of increased competing mortality risks associated with smoking.

CT screening for lung cancer: update 2007

Screening is the pursuit of the early diagnosis of cancer before symptoms occur. The purpose of early diagnosis is to provide early treatment, which potentially prevents death from the cancer. The usefulness of screening depends on how early the cancer can be diagnosed and how many deaths can be prevented by early treatment as compared with later symptom-prompted diagnosis and treatment. The goal of the Early Lung Cancer Action Project investigators was to develop an efficient methodology that would provide an ever-accumulating, continually updated body of evidence for evaluation of emerging new technologies for screening for cancer. This methodology recognizes that screening is a sequential process that starts with the pursuit of the early diagnosis of cancer followed by early treatment. It also recognizes that diagnostic research is fundamentally different from treatment research. To fully understand the current discussions on the evidence for lung cancer screening, key definitions are provided, including the differentiation between the first, baseline round of screening and all subsequent rounds of repeat screening and baseline and repeat cancers and their distribution by cell type. These definitions are critical in analyzing the results of various screening reports as they are not used by all. To provide optimal screening, a regimen for the diagnostic workup must be specified starting with the definition of the initial test, its positive result, and the workup for a positive result leading to a diagnosis of cancer. Assessment of diagnostic performance does not require a control group, but does require confirmation of the diagnosis. For assessment of the effectiveness of early treatment, a comparison group is needed. The comparison group may be formed by randomly assigning people with screen-diagnosed lung cancer to immediate or delayed treatment, as has been done for prostate cancer. This provides a direct assessment of any potential overdiagnosis of the cancer resulting from screening. Alternatively, a quasiexperimental control group can be used consisting of participants diagnosed with the cancer who have refused or delayed their treatment even though they are candidates for it.

Screening for lung cancer

OBJECTIVE

The purpose of our review is to discuss the current state of lung cancer screening using CT in the context of defined criteria for effective screening.

CONCLUSION

Although there are hopeful developments in lung cancer screening, a number of unresolved issues must be answered before adopting screening on a large scale. Currently no data exist to suggest that lung cancer screening with CT will result in a decrease in lung cancer mortality.

Cancer screening in renal transplant recipients: what is the evidence?

Increased cancer risk is well established in the renal transplant population. Little, however, is known about the benefits and harms of cancer screening, treatment effectiveness, and the overall cancer prognosis in renal transplant recipients. In this study, we critically appraised guidelines for cancer screening in the renal transplant and general populations using standard criteria for an evidence-based screening program. Guidelines were included when they were applied to adult participants, had objectives specific to cancer screening, and were written in English. Recommendations for breast and colorectal cancer screening in the general population were supported by evidence of cancer-specific mortality benefits from randomized, controlled trials of cancer screening. Convincing evidence from observational studies had demonstrated population cervical cancer screening was effective, also, test performance of mammography, faecal occult blood testing, and Pap smear were accurate. Population breast, colorectal, and cervical cancer screening also appeared to be good value for money in the general population. On the contrary, recommendations for cancer screening in renal transplant recipients were entirely extrapolated from data in the general population. Studies in the general population have led to the development of cancer screening guidelines in transplant recipients. Because of increased cancer risk, differences in diagnostic test performance, competing risks for deaths from causes such as cardiovascular disease and reduced overall life expectancies, validity of their recommendations are uncertain. Future studies are needed to address these issues to provide the necessary evidence for informed decision-making.

Could CT screening for lung cancer ever be cost effective in the United Kingdom?

Background

The absence of trial evidence makes it impossible to determine whether or not mass screening for lung cancer would be cost effective and, indeed, whether a clinical trial to investigate the problem would be justified. Attempts have been made to resolve this issue by modelling, although the complex models developed to date have required more real-world data than are currently available. Being founded on unsubstantiated assumptions, they have produced estimates with wide confidence intervals and of uncertain relevance to the United Kingdom.

Method

I develop a simple, deterministic, model of a screening regimen potentially applicable to the UK. The model includes only a limited number of parameters, for the majority of which, values have already been established in non-trial settings. The component costs of screening are derived from government guidance and from published audits, whilst the values for test parameters are derived from clinical studies. The expected health gains as a result of screening are calculated by combining published survival data for screened and unscreened cohorts with data from Life Tables. When a degree of uncertainty over a parameter value exists, I use a conservative estimate, i.e. one likely to make screening appear less, rather than more, cost effective.

Results

The incremental cost effectiveness ratio of a single screen amongst a high-risk male population is calculated to be around £14,000 per quality-adjusted life year gained. The average cost of this screening regimen per person screened is around £200. It is possible that, when obtained experimentally in any future trial, parameter values will be found to differ from those previously obtained in non-trial settings. On the basis both of differing assumptions about evaluation conventions and of reasoned speculations as to how test parameters and costs might behave under screening, the model generates cost effectiveness ratios as high as around £20,000 and as low as around £7,000.

Conclusion

It is evident that eventually being able to identify a cost effective regimen of CT screening for lung cancer in the UK is by no means an unreasonable expectation.

Screening for Lung Cancer

BACKGROUND

Lung cancer typically exhibits symptoms only after the disease has spread, making cure unlikely. Because early-stage disease can be successfully treated, a screening technique that can detect lung cancer before it has spread might be useful in decreasing lung cancer mortality.

OBJECTIVES

In this article, we review the evidence for and against screening for lung cancer with low-dose CT and offer recommendations regarding its usefulness for asymptomatic patients with no history of cancer.

RESULTS

Studies of lung cancer screening with chest radiograph and sputum cytology have failed to demonstrate that screening lowers lung cancer mortality rates. Published studies of newer screening technologies such as low-dose CT and "biomarker" screening report primarily on lung cancer detection rates and do not present sufficient data to determine whether the newer technologies will benefit or harm. Although researchers are conducting randomized trials of low-dose CT, results will not be available for several years. In the meantime, cost-effectiveness analyses and studies of nodule growth are considering practical questions but producing inconsistent findings.

CONCLUSIONS

For high-risk populations, no screening modality has been shown to alter mortality outcomes. We recommend that individuals undergo screening only when it is administered as a component of a well-designed clinical trial with appropriate human subjects' protections.

The cost-effectiveness of radon-proof membranes in new homes: A case study from Brixworth, Northamptonshire, UK

Installing radon-proof membranes in new homes can reduce the exposure of those living in the properties to the radiation caused by a build up of radon gas. This paper considers whether doing so is cost-effective for a group of new houses constructed in the village of Brixworth, Northamptonshire, UK. The measure of cost-effectiveness used is cost per quality-adjusted life-year gained. Brixworth is situated in a high-radon area of the UK. As a result, all properties built there must comply with building regulations that require installation of membranes. When compared with a number of medical interventions and a well-established threshold value for cost-effectiveness, the use of membranes in new properties in the village is shown to be cost-effective. This result also pertains when adjustment is made for a number of assumptions adopted in estimating the cost per quality-adjusted life-year gained. The paper concludes with suggestions for future research to establish whether or not the use of membranes in new properties in other areas would be cost-effective.

Screening for lung cancer

The lethality of lung cancer is related to the advanced stage at diagnosis. Initial studies have demonstrated that screening computed tomography (CT) is effective in diagnosing lung cancer at an earlier stage when compared with current clinical practice, however the best clinical approach for screening detected nodules has to be defined. The population to be identified as high risk should be over 50 years of age and should have smoked at least one pack/day for 20 years. CT protocols should use multidetector CT, low dose and a 2.5 reconstruction interval. Diagnostic work-up on detected nodules should be designed according to size and consider CT at 3 or 12 months to evaluate doubling time, CT enhancement, PET/CT and/or FNAB or VATS. The prevalence of lung cancer in the screened population is 1.1%–2.7%, and the incidence is 0.2%–1.1%. Eighty-one percent of cancers are diagnosed in stage I. The percentage of surgery performed for benign lesions ranges from 21% to 55%. In our series, the overall mortality rate was 3.2% in 5 years. The results of randomized clinical studies, when available, will assess the real efficacy of CT in reducing lung cancer related mortality.

Survival of patients with stage I lung cancer detected on CT screening

BACKGROUND

The outcome among patients with clinical stage I cancer that is detected on annual screening using spiral computed tomography (CT) is unknown.

METHODS

In a large collaborative study, we screened 31,567 asymptomatic persons at risk for lung cancer using low-dose CT from 1993 through 2005, and from 1994 through 2005, 27,456 repeated screenings were performed 7 to 18 months after the previous screening. We estimated the 10-year lung-cancer-specific survival rate among participants with clinical stage I lung cancer that was detected on CT screening and diagnosed by biopsy, regardless of the type of treatment received, and among those who underwent surgical resection of clinical stage I cancer within 1 month. A pathology panel reviewed the surgical specimens obtained from participants who underwent resection.

RESULTS

Screening resulted in a diagnosis of lung cancer in 484 participants. Of these participants, 412 (85%) had clinical stage I lung cancer, and the estimated 10-year survival rate was 88% in this subgroup (95% confidence interval [CI], 84 to 91). Among the 302 participants with clinical stage I cancer who underwent surgical resection within 1 month after diagnosis, the survival rate was 92% (95% CI, 88 to 95). The 8 participants with clinical stage I cancer who did not receive treatment died within 5 years after diagnosis.

CONCLUSIONS

Annual spiral CT screening can detect lung cancer that is curable.

Validity of the Assessment of Quality of Life (AQoL) utility instrument in patients with operable and inoperable lung cancer

There have been few longitudinal studies of quality of life in patients with all stages of lung cancer, particularly those that have included measures of utility. The purpose of this study was to examine the psychometric properties of the Assessment of Quality of Life instrument (AQoL) in patients with lung cancer. The AQoL is a health-related quality of life questionnaire and provides a descriptive system for a multi-attribute utility instrument (MAU), so that scores can be used in cost-utility evaluations. In the present study the reliability (internal consistency) of the AQoL was examined and the concurrent validity was assessed using the Medical Outcomes 36-item Short Form Health Survey (SF-36) as the comparator instrument. The sensitivity to different health states of the AQoL and the responsiveness to change over time was also examined. A prospective, non-experimental cohort study was undertaken. Ninety-two participants with all stages of lung cancer were recruited from a tertiary multi-disciplinary lung cancer clinic. Ninety participants had non-small cell lung cancer (NSCLC) and two had limited stage small cell lung cancer. The AQOL and SF-36 surveys were administered concurrently at baseline. In patients with NSCLC the surveys were then repeated 3 and 6 months later. Correlations between the baseline AQoL summary scales and SF-36 summary scales support the divergent and convergent validity of the AQoL. Reliability was also found to be sufficient (Cronbach's Alpha=0.76). In addition, in patients with inoperable NSCLC, baseline AQoL scores were found to be predictive of survival at 6 months in Cox proportional hazards multivariate analysis. However, the physical components summary score of the SF-36 was more sensitive to differences in health states between patients with different stages of NSCLC at 6 months of follow-up and more responsive to change over time in both operable and inoperable patients with NSCLC than the AQoL. The findings support the construct validity and reliability of the AQoL in this population. However, there remains some uncertainty about whether the AQoL has sufficient sensitivity to different health states in this population. Further studies using other MAU instruments may determine whether alternative instruments are more sensitive to different health states in individuals with lung cancer.

A new methodology for cost-effectiveness studies of domestic radon remediation programmes: quality-adjusted life-years gained within primary care trusts in central England

Radon is a naturally occurring radioactive gas, high levels of which are associated with geological formations such as those found in Northamptonshire and North Oxfordshire in the UK. The UK's National Radiological Protection Board have designated both districts as radon Affected Areas. Radiation levels due to radon, therefore, exceed 200 Bq m(-3), the UK's domestic Action Level, in over one percent of domestic properties. Because of radon's radioactivity, exposure to the gas can potentially cause lung cancer, and has been linked to some 2000 deaths a year in the UK. Consequently, when radiation levels exceed the Action Level, remediation against radon's effects is recommended to householders. This study examines the cost-effectiveness of remediation measures in Northamptonshire and North Oxfordshire by estimating cost per quality-adjusted life-year gained in four Primary Care Trusts, organisations that play a key public health policy role in the UK's National Health Service. The study is the first to apply this approach to estimating the cost-effectiveness of radon remediation programmes. Central estimates of cost per quality-adjusted life-year in the four Primary Care Trusts range from 6143pounds to 10323pounds. These values, when assessed against generally accepted criteria, suggest the remediation programmes in the trusts were cost-effective. Policy suggestions based on the estimates, and designed to improve cost-effectiveness further, are proposed for the four Primary Care Trusts and the UK's National Health Service.

Computed tomography screening for lung cancer in Hodgkin's lymphoma survivors: decision analysis and cost-effectiveness analysis

BACKGROUND

Hodgkin's lymphoma patients have an elevated risk of developing lung cancer and may be targeted for lung cancer screening. We used a decision-analytic model to estimate the potential clinical benefits and cost-effectiveness of computed tomography (CT) screening for lung cancer in Hodgkin's lymphoma survivors.

MATERIALS AND METHODS

We developed a Markov decision-analytic model to compare annual low-dose CT screening versus no screening in a hypothetical cohort of patients diagnosed with stage IA-IIB Hodgkin's lymphoma at age 25, with screening starting 5 years after initial diagnosis. We derived model parameters from published studies and the Surveillance, Epidemiology and End Results (SEER) Program, and assumed that stage-shift produces a survival benefit.

RESULTS

Annual CT screening increased survival by 0.64 years for smokers and 0.16 years for non-smokers. The corresponding benefits in quality-adjusted survival were 0.58 quality-adjusted life-years (QALYs) for smokers and 0.14 QALYs for non-smokers. The incremental cost-effectiveness ratios for annual CT screening compared with no screening were $34 100/QALY for smokers and $125 400/QALY for non-smokers.

CONCLUSIONS

Our analysis suggests that if early promising results for lung cancer screening hold, CT screening for lung cancer may increase survival and quality-adjusted survival among Hodgkin's lymphoma survivors, with a benefit and incremental cost-effectiveness ratio for smokers comparable to that of other recommended cancer screening strategies.

CT screening for lung cancer: update 2005

Currently available results on CT screening for lung cancer show that (1) the work-up on baseline screening can be confined to less than 15% of the individuals and to less than 6% on annual repeat screening, (2) almost all cases are detected by screening with very few diagnoses made between screening on the prompting of symptoms, and (3) over 80% of all the diagnoses are of stage I. This diagnostic performance results from following the I-ELCAP regimen of screening which defines a positive result of the initial CT in the regimen as well as the work-up leading to a diagnosis of lung cancer. The diagnostic performance raises prognostic questions as to the genuineness and curability of these screen-diagnosed lung cancers. All diagnoses of malignancy were confirmed by an expert pathology review and found to represent genuine lung cancer as defined by the 2004 World Health Organization pathologic criteria. Estimates based on growth rates suggest that about 90% of the baseline-diagnosed stage I cancers are genuine cancers, as are essentially all of those diagnosed on annual repeat screening. Preliminary results of the curability of genuine screen-diagnosed stage I lung cancers indicate a high curability rate of more than 90%. This suggests that more than a high proportion of deaths from lung cancer can be prevented by CT screening followed by early resection. Using these results, the benefit of a single round of CT screening can be determined for an individual based on the age and smoking history.

Estimating transitions between symptom severity states over time in schizophrenia: a Bayesian meta-analytic approach

We obtain the posterior predictive distribution of transition probabilities between symptom severity states over time for patients with schizophrenia by (i) employing a Bayesian meta-analysis of published clinical trials and observational studies to estimate the posterior distribution of parameters that guide changes in Positive and Negative Syndrome Scale (PANSS) scores over time and under the influence of various drugs and (ii) by propagating the variability from the posterior distributions of the parameters through a micro-simulation model that is formulated based on schizophrenia progression. Results show detailed differences among haloperidol, risperidone and olanzapine in controlling various levels of severities of positive, negative and joint symptoms over time. For example, risperidone seems best in controlling severe positive symptoms while olanzapine is the worst in that during the first quarter of drug treatment; however, olanzapine seems to be best in controlling severe negative symptoms across all four quarters of treatment while haloperidol is the worst in this regard. These details may further serve to better estimate quality of life of patients and aid in resource utilization decisions in treating schizophrenic patients. In addition, consistent estimation of uncertainty in the time-profile parameters also has important implications for the practice of cost-effectiveness analysis and for future resource allocation policies in schizophrenia treatment.