Research

Screening men for abdominal aortic aneurysm: 10 year mortality and cost effectiveness results from the randomised Multicentre Aneurysm Screening Study

BMJ 2009; 338 doi: https://doi.org/10.1136/bmj.b2307 (Published 24 June 2009) Cite this as: BMJ 2009;338:b2307
  1. S G Thompson, director1,
  2. H A Ashton, overall trial coordinator2,
  3. L Gao, statistician1,
  4. R A P Scott, consultant vascular surgeon (retired)2
  5. on behalf of the Multicentre Aneurysm Screening Study Group
  1. 1MRC Biostatistics Unit, Institute of Public Health, Cambridge CB2 0SR
  2. 2Scott Research Unit, St Richard’s Hospital, Chichester
  1. Correspondence to: S G Thompson simon.thompson{at}mrc-bsu.cam.ac.uk
  • Accepted 27 April 2009

Abstract

Objectives To assess whether the mortality benefit from screening men aged 65-74 for abdominal aortic aneurysm decreases over time, and to estimate the long term cost effectiveness of screening.

Design Randomised trial with 10 years of follow-up.

Setting Four centres in the UK. Screening and surveillance was delivered mainly in primary care settings, with follow-up and surgery offered in hospitals.

Participants Population based sample of 67 770 men aged 65-74.

Interventions Participants were individually allocated to invitation to ultrasound screening (invited group) or to a control group not offered screening. Patients with an abdominal aortic aneurysm detected at screening underwent surveillance and were offered surgery if they met predefined criteria.

Main outcome measures Mortality and costs related to abdominal aortic aneurysm, and cost per life year gained.

Results Over 10 years 155 deaths related to abdominal aortic aneurysm (absolute risk 0.46%) occurred in the invited group and 296 (0.87%) in the control group (relative risk reduction 48%, 95% confidence interval 37% to 57%). The degree of benefit seen in earlier years of follow-up was maintained in later years. Based on the 10 year trial data, the incremental cost per man invited to screening was £100 (95% confidence interval £82 to £118), leading to an incremental cost effectiveness ratio of £7600 (£5100 to £13 000) per life year gained. However, the incidence of ruptured abdominal aortic aneurysms in those originally screened as normal increased noticeably after eight years.

Conclusions The mortality benefit of screening men aged 65-74 for abdominal aortic aneurysm is maintained up to 10 years and cost effectiveness becomes more favourable over time. To maximise the benefit from a screening programme, emphasis should be placed on achieving a high initial rate of attendance and good adherence to clinical follow-up, preventing delays in undertaking surgery, and maintaining a low operative mortality after elective surgery. On the basis of current evidence, rescreening of those originally screened as normal is not justified.

Trial registration Current Controlled Trials ISRCTN37381646.

Footnotes

  • We thank Stephanie Druce (Chichester) and Liz Hardy (Oxford) for data collection, Martin Buxton (Brunel) for advice on health economics, Lois Kim (London School of Hygiene and Tropical Medicine) for help with statistical programming, and the referees for their comments.

  • Contributors: SGT, current principal investigator of MASS, supervised the statistical analysis, drafted the paper, and is the guarantor. HAA is the overall trial coordinator for MASS. LG undertook the statistical analyses. RAPS, the original principal investigator of MASS, is responsible for the clinical aspects. All authors reviewed the manuscript and contributed to the final version.

  • Funding: This work was supported by the Medical Research Council (grant numbers G0601031 and U.1052.00.001). The funder had no role in the design, implementation, analysis, or interpretation of the study.

  • Competing interests: None declared.

  • Ethical approval: Southampton and south west Hampshire ethics committee approved the extended follow-up in MASS.

  • Accepted 27 April 2009

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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