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.

Cost-effectiveness analysis of reflex testing for Lynch syndrome in women with endometrial cancer in the UK setting.

BACKGROUND: Lynch syndrome is a hereditary cancer syndrome caused by constitutional pathogenic variants in the DNA mismatch repair (MMR) system, leading to increased risk of colorectal, endometrial and other cancers. The study aimed to identify the incremental costs and consequences of strategies to identify Lynch syndrome in women with endometrial cancer. METHODS: A decision-analytic model was developed to evaluate the relative cost-effectiveness of reflex testing strategies for identifying Lynch syndrome in women with endometrial cancer taking the NHS perspective and a lifetime horizon. Model input parameters were sourced from various published sources. Consequences were measured using quality-adjusted life years (QALYs). A cost-effectiveness threshold of £20 000/QALY was used. RESULTS: Reflex testing for Lynch syndrome using MMR immunohistochemistry and MLH1 methylation testing was cost-effective versus no testing, costing £14 200 per QALY gained. There was uncertainty due to parameter imprecision, with an estimated 42% chance this strategy is not cost-effective compared with no testing. Age had a significant impact on cost-effectiveness, with testing not predicted to be cost-effective in patients aged 65 years and over. CONCLUSIONS: Testing for Lynch syndrome in younger women with endometrial cancer using MMR immunohistochemistry and MLH1 methylation testing may be cost-effective. Age cut-offs may be controversial and adversely affect implementation.

Prediction of spontaneous preterm birth: no good test for predicting a spontaneous preterm birth.

PURPOSE OF REVIEW: Spontaneous preterm birth complicates 3-11% of pregnancies and is a major cause of neonatal mortality and morbidity worldwide. If accurate tests can be identified, a potentially effective screening strategy with an adjunct preventive therapy may be trialled to reduce the rate of spontaneous preterm birth or effective measures be deployed at an early stage of a suspected spontaneous preterm labour before the onset of cervical changes to ameliorate prematurity complications. RECENT FINDINGS: There are many tests predicting spontaneous preterm births, published in the literature individually or in a systematic review. The information has not been collated about all candidate tests simultaneously in a systematic review incorporating a framework on how these tests may be evaluated, modelled with an intervention to provide a number needed to treat and test to inform decision-making. SUMMARY: There were 319 studies evaluating 22 tests. There are many promising tests, for example, history of previous spontaneous preterm birth, cervicovaginal swabs for markers such as fibronectin or HCG, cervical ultrasound, serum CRP and amniotic fluid interleukins for predicting spontaneous preterm birth, but none have exceptional accuracy and the quality of studies was generally poor. Some tests were able to achieve high LR+, but at the expense of LR-, that is, tests good for ruling in disease were poor for ruling out disease and vice versa.

Where are the systematic reviews in transfusion medicine? A study of the transfusion evidence base.

Transfusion medicine has become a large and complex specialty. Although there are now systematic reviews covering many aspects of transfusion, these span a large number of clinical areas and are published across more than a hundred different medical journals, making it difficult for transfusion medicine practitioners and researchers to keep abreast of the current high-level evidence. In response to this problem, NHS Blood and Transplant's Systematic Review Initiative (SRI) has produced a comprehensive overview of systematic reviews in transfusion medicine. A systematic search (to December 2009) and screening procedure were followed by the appraisal of systematic reviews according to predefined inclusion criteria. The 340 eligible systematic reviews were mapped to 10 transfusion intervention groups and 14 topic groups within clinical medicine. Trends in the systematic review literature were examined and gaps in the literature described. The spread of systematic reviews across clinical areas was found to be very uneven, with some areas underreviewed and others with multiple systematic reviews on the same topic, making the identification of the best evidence for current transfusion practice a continuing challenge. References and links to all systematic reviews included in this overview can be freely accessed via the SRI's new online database, the Transfusion Evidence Library (www.transfusionguidelines.org).

An economic evaluation of alternative test-intervention strategies to prevent spontaneous pre-term birth in singleton pregnancies.

OBJECTIVE: To investigate the potential cost-effectiveness of alternative 'test-and-treat' strategies in the prevention of spontaneous pre-term birth before 34 and 37 weeks' gestation. DESIGN: Model-based economic evaluation. Setting. Clinics, general practices, health centers or any setting delivering antenatal care. POPULATION: Asymptomatic women in early pregnancy and symptomatic women with threatened pre-term labor in later pregnancy. METHODS: Data from systematic reviews of effectiveness and accuracy were combined into strategies and analyzed using a decision-tree model. Full deterministic and probabilistic sensitivity analyses were carried out. MAIN OUTCOME MEASURES: Spontaneous pre-term labor avoided for asymptomatic women and spontaneous pre-term birth avoided for symptomatic women. RESULTS: The systematic reviews identified evidence on the accuracy of 22 types of tests and on the effectiveness of 40 possible interventions. Cost data were based on secondary evidence, supplemented with primary data from local sources. Testing prior to intervention was not shown to be the most cost-effective strategy in the main analyses for 34 and 37 weeks. Prophylactic fish oil in asymptomatic women, without prior testing, was highlighted as potentially cost-effective in preventing threatened pre-term labor before 34 weeks. In symptomatic women with a viable pregnancy, indomethacin without prior testing was a potentially cost-effective strategy to prevent pre-term birth occurring before 37 weeks. CONCLUSION: An effective, affordable and safe intervention applied to all mothers without prior testing is likely to be the most cost-effective strategy in the prevention of spontaneous pre-term labor and birth. The results reported in this paper are important for prioritizing future research, world-wide.

Autologous bone marrow stem cells to treat acute myocardial infarction: a systematic review.

AIMS: To provide systematic assessment of the safety and efficacy of autologous bone marrow-derived stem cell (BMSC) transplantation in acute myocardial infarction (AMI) based on clinical evidence. METHODS AND RESULTS: The search strategy included MEDLINE, EMBASE, the Cochrane Library, and Current Controlled Trials Register through to August 2007 for randomized controlled trials of BMSC treatment for AMI. Thirteen trials (14 comparisons) with a total of 811 participants were included. Data were analysed using a random effects model. Overall, stem cell therapy improved left ventricular ejection fraction (LVEF) by 2.99% [95% confidence interval (CI), 1.26-4.72%, P = 0.0007], significantly reduced left ventricular end-systolic volume (LVESV) by 4.74 mL (95% CI, -7.84 to -1.64 mL, P = 0.003), and myocardial lesion area by 3.51% (95% CI, -5.91 to -1.11%, P = 0.004) compared with controls. Subgroup analysis revealed that there was statistical significant difference in LEVF in favour of BMSCs when cells were infused within 7 days following AMI and when the BMSC dose administered was higher than 10(8) BMSCs. In addition, there were trends in favour of benefit for most clinical outcomes examined, although it should be acknowledged that the 95%CI included no significant difference. CONCLUSION: Stem cell treatment for AMI still holds promise. Clinically, these data suggest that improvement over conventional therapy can be achieved. Further, adequately powered trials using optimal dosing, longer term outcome assessments, more reliable, and more patient-centred outcomes are required.