title: The ETTAA study protocol: a UK-wide observational study of 'Effective Treatments for Thoracic Aortic Aneurysm'.
abstract: BACKGROUND
  Chronic thoracic aortic aneurysm (CTAA) affecting the arch or descending aorta is an indolent but life-threatening condition with a rising prevalence as the UK population ages. Treatment may be in the form of open surgical repair (OSR) surgery, endovascular stent grafting (ESG) or best medical therapy (BMT). Currently, there is no consensus on the best management strategy, and no UK-specific economic studies that assess outcomes beyond the chosen procedure, but this is required in the context of greater demand for treatment and limited National Health Service (NHS) resources.
  
  
  METHODS
  This is a prospective, multicentre observational study with statistical and economic modelling of patients with CTAA affecting the arch or descending aorta. We aim to gain an understanding of how treatments are currently chosen, and to determine the clinical effectiveness and cost-effectiveness of the three available treatment strategies (BMT, ESG and OSR). This will be achieved by: (1) following consecutive patients who are referred to the teams collaborating in this proposal and collecting data regarding quality of life (QoL), medical events and hospital stays over a maximum of 5 years; (2) statistical analysis of the comparative effectiveness of the three treatments; and (3) economic modelling of the comparative cost-effectiveness of the three treatments. Primary study outcomes are: aneurysm growth, QoL, freedom from reintervention, freedom from death or permanent neurological injury, incremental cost per quality-adjusted life year gained.
  
  
  BACKGROUND
  The study will generate an evidence base to guide patients and clinicians to determine the indications and timing of treatment, as well as informing healthcare decision-makers about which treatments the NHS should provide. The study has achieved ethical approval and will be disseminated primarily in the form of a Health Technology Assessment monograph at its completion.
  
  
  BACKGROUND
  ISRCTN04044627.
authors.affiliation: Papworth Hospital, Cambridge, UK.
authors.forename: Priya
authors.initials: P
authors.lastname: Sastry
authors.affiliation: Papworth Hospital, Cambridge, UK.
authors.forename: Victoria
authors.initials: V
authors.lastname: Hughes
authors.affiliation: Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Hayes
authors.affiliation: Royal Liverpool Hospital, Liverpool, Merseyside, UK.
authors.forename: Srinivasa
authors.initials: S
authors.lastname: Vallabhaneni
authors.affiliation: Clinical Trials Research Unit, University of Leeds, Leeds, UK.
authors.forename: Linda
authors.initials: L
authors.lastname: Sharples
authors.affiliation: St George's Hospital, London, UK.
authors.forename: Matt
authors.initials: M
authors.lastname: Thompson
authors.affiliation: Papworth Hospital, Cambridge, UK.
authors.forename: Pedro
authors.initials: P
authors.lastname: Catarino
authors.affiliation: Papworth Hospital, Cambridge, UK.
authors.forename: Narain
authors.initials: N
authors.lastname: Moorjani
authors.affiliation: Institute of Health & Society, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Luke
authors.initials: L
authors.lastname: Vale
authors.affiliation: Institute of Health & Society, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Joanne
authors.initials: J
authors.lastname: Gray
authors.affiliation: Southampton Health Technology Assessments Centre (SHTAC), University of Southampton, Southampton, Hampshire, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Cook
authors.affiliation: Yale Center for Thoracic Aortic Disease, New Haven, Connecticut, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Elefteriades
authors.affiliation: Papworth Hospital, Cambridge, UK.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Large
mesh_terms: D000367:Age Factors; D017545:Aortic Aneurysm, Thoracic / Q000453:epidemiology / Q000628:therapy*; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D057510:Endovascular Procedures; D006801:Humans; D015995:Prevalence; D011446:Prospective Studies; D011788:Quality of Life; D015607:Stents; D016896:Treatment Outcome; D006113:United Kingdom / Q000453:epidemiology; D057832:Watchful Waiting
keywords: VASCULAR MEDICINE