43 research outputs found

    Cost of providing cell-free DNA screening for Down syndrome in Finland using different strategies

    Get PDF
    Introduction A financial analysis is carried out to assess costs and benefits of providing cell-free DNA screening in Finland, using different strategies. Materials and methods Three cell-free DNA screening strategies are considered: Primary, all women; Secondary, those with positive Combined test; and Contingent, the 10-30% with the highest Combined test risks. Three costs are estimated: additional cost for 10,000 pregnancies compared with the Combined test; 'marginal' cost of avoiding a Down syndrome birth which occurs in a pregnancy that would have been false-negative using the Combined test; and marginal cost of preventing the iatrogenic loss of a non-Down syndrome birth which occurs in a pregnancy that would have been false-positive. Results Primary cell-free DNA will require additional funds of euro250,000. The marginal cost per Down syndrome birth avoided is considerably less than the lifetime medical and indirect cost; the marginal cost per unaffected iatrogenic fetal loss prevented is higher than one benefit measure but lower than another. If the ultrasound component of the Combined test is retained, as would be in Finland, the additional funds required rise to euro992,000. Secondary cell-free DNA is cost-saving as is a Contingent strategy with 10% selected but whilst when 20-30% costs rise they are much less than for the Primary strategy and are cost-beneficial. Conclusions When considering the place of cell-free DNA screening it is important to make explicit the additional and marginal costs of different screening strategies and the associated benefits. Under most assumptions the balance is favorable for Contingent screening.Peer reviewe

    Annual mammographic screening to reduce breast cancer mortality in women from age 40 years:long-term follow-up of the UK Age RCT

    Get PDF
    © Queen’s Printer and Controller of HMSO 2020. This work was produced by Duffy et al. under the terms of a commissioning contract issued by the Secretary of State for Health and Social Care. This issue may be freely reproduced for the purposes of private research and study and extracts (or indeed, the full report) may be included in professional journals provided that suitable acknowledgement is made and the reproduction is not associated with any form of advertising. Applications for commercial reproduction should be addressed to: NIHR Journals Library, National Institute for Health Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK.BACKGROUND: There remains disagreement on the long-term effect of mammographic screening in women aged 40-49 years.OBJECTIVES: The long-term follow-up of a randomised controlled trial that offered annual mammography to women aged 40-49 years. The estimation of the effect of these mammograms on breast cancer and other-cause mortality, and the effect on incidence, with implications for overdiagnosis.DESIGN: An individually randomised controlled trial comparing offering annual mammography with offering usual care in those aged 40-48 years, and thus evaluating the effect of annual screening entirely taking place before the age of 50 years. There was follow-up for an average of 23 years for breast cancer incidence, breast cancer death and death from other causes. We analysed the mortality and incidence data by Poisson regression and estimated overdiagnosis formally using Markov process models.SETTING: Twenty-three screening units in England, Wales and Scotland within the NHS Breast Screening Programme.PARTICIPANTS: Women aged 39-41 years were recruited between 1990 and 1997. After exclusions, a total of 53,883 women were randomised to undergo screening (the intervention group) and 106,953 women were randomised to have usual care (the control group).INTERVENTIONS: The intervention group was invited to an annual breast screen with film mammography, two view at first screen and single view thereafter, up to and including the calendar year of their 48th birthday. The control group received no intervention. Both groups were invited to the National Programme from the age of 50 years, when screening is offered to all women in the UK.MAIN OUTCOME MEASURES: The main outcome measures were mortality from breast cancers diagnosed during the intervention phase of the trial (i.e. before the first National Programme screen at 50 years), mortality from all breast cancers diagnosed after randomisation, all-cause mortality, mortality from causes other than breast cancer, and the incidence of breast cancer.RESULTS: There was a statistically significant 25% reduction in mortality from breast cancers diagnosed during the intervention phase at 10 years' follow-up (relative rate 0.75, 95% confidence interval 0.58 to 0.97; p = 0.03). No reduction was observed thereafter (relative rate 0.98, 95% confidence interval 0.79 to 1.22). Overall, there was a statistically non-significant 12% reduction (relative rate 0.88, 95% confidence interval 0.74 to 1.03; p = 0.1). The absolute benefit remained approximately constant over time, at one death prevented per 1000 women screened. There was no effect of intervention on other-cause mortality (relative rate 1.02, 95% confidence interval 0.97 to 1.07; p = 0.4). The intervention group had a higher incidence of breast cancer than the control group during the intervention phase of the trial, but incidence equalised immediately on the first National Programme screen at the age of 50-52 years.LIMITATIONS: There was 31% average non-compliance with screening and three centres had to cease screening for resource and capacity reasons.CONCLUSIONS: Annual mammographic screening at the age of 40-49 years resulted in a relative reduction in mortality, which was attenuated after 10 years. It is likely that digital mammography with two views at all screens, as practised now, could improve this further. There was no evidence of overdiagnosis in addition to that which already results from the National Programme carried out at later ages.FUTURE WORK: There is a need for research on the effects of modern mammographic protocols and additional imaging in this age group.TRIAL REGISTRATION: Current Controlled Trials ISRCTN24647151.FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 55. See the NIHR Journals Library website for further project information. Other funding in the past has been received from the Medical Research Council, Cancer Research UK, the Department of Health and Social Care, the US National Cancer Institute and the American Cancer Society.Peer reviewe

    Effect of mammographic screening from age 40 years on breast cancer mortality (UK Age trial):final results of a randomised, controlled trial

    Get PDF
    Copyright © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.BACKGROUND: The appropriate age range for breast cancer screening remains a matter of debate. We aimed to estimate the effect of mammographic screening at ages 40-48 years on breast cancer mortality. METHODS: We did a randomised, controlled trial involving 23 breast screening units across Great Britain. We randomly assigned women aged 39-41 years, using individual randomisation, stratified by general practice, in a 1:2 ratio, to yearly mammographic screening from the year of inclusion in the trial up to and including the calendar year that they reached age 48 years (intervention group), or to standard care of no screening until the invitation to their first National Health Service Breast Screening Programme (NHSBSP) screen at approximately age 50 years (control group). Women in the intervention group were recruited by postal invitation. Women in the control group were unaware of the study. The primary endpoint was mortality from breast cancers (with breast cancer coded as the underlying cause of death) diagnosed during the intervention period, before the participant's first NHSBSP screen. To study the timing of the mortality effect, we analysed the results in different follow-up periods. Women were included in the primary comparison regardless of compliance with randomisation status (intention-to-treat analysis). This Article reports on long-term follow-up analysis. The trial is registered with the ISRCTN registry, ISRCTN24647151. FINDINGS: 160 921 women were recruited between Oct 14, 1990, and Sept 24, 1997. 53 883 women (33·5%) were randomly assigned to the intervention group and 106 953 (66·5%) to the control group. Between randomisation and Feb 28, 2017, women were followed up for a median of 22·8 years (IQR 21·8-24·0). We observed a significant reduction in breast cancer mortality at 10 years of follow-up, with 83 breast cancer deaths in the intervention group versus 219 in the control group (relative rate [RR] 0·75 [95% CI 0·58-0·97]; p=0·029). No significant reduction was observed thereafter, with 126 deaths versus 255 deaths occurring after more than 10 years of follow-up (RR 0·98 [0·79-1·22]; p=0·86). INTERPRETATION: Yearly mammography before age 50 years, commencing at age 40 or 41 years, was associated with a relative reduction in breast cancer mortality, which was attenuated after 10 years, although the absolute reduction remained constant. Reducing the lower age limit for screening from 50 to 40 years could potentially reduce breast cancer mortality. FUNDING: National Institute for Health Research Health Technology Assessment programme.Peer reviewe

    Models for intuitionistic logic

    No full text
    In this work I develop a formalization (M-L) of Martin-Löf type theory, the main concern being an accurate definition of what it is to be a model of M-L. Using this definition, I proceed with actual models of M-L (mainly realizability models) to establish the relative consistency of many intuitionistic principles. In addition to their consistency I investigate their interrelationship. The strongest principles which are shown to be consistent with M-L are Church's Thesis and the Fan Theorem. The expressive power of M-L is used to formalize certain theories. The Theory of Real Numbers, an Intuitionistic Set Theory and Category Theory are all formalizable. The constructions of the latter are used to describe Kripke Models of M-L. Finally, I prove that the subsystem of M-L obtained by dropping the rules for cartesian products of types and without rules for universes of types has proof theoretic ordinal ωω.</p

    Models for intuitionistic logic: (with special reference to 'Martin-Löf Type Theory')

    No full text
    In this work I develop a formalization (M-L) of Martin-Löf type theory, the main concern being an accurate definition of what it is to be a model of M-L. Using this definition, I proceed with actual models of M-L (mainly realizability models) to establish the relative consistency of many intuitionistic principles. In addition to their consistency I investigate their interrelationship. The strongest principles which are shown to be consistent with M-L are Church's Thesis and the Fan Theorem. The expressive power of M-L is used to formalize certain theories. The Theory of Real Numbers, an Intuitionistic Set Theory and Category Theory are all formalizable. The constructions of the latter are used to describe Kripke Models of M-L. Finally, I prove that the subsystem of M-L obtained by dropping the rules for cartesian products of types and without rules for universes of types has proof theoretic ordinal ωω
    corecore