title: Evaluating outcomes used in cardiothoracic surgery interventional research: a systematic review of reviews to develop a core outcome set.
abstract: BACKGROUND
  When planning clinical trials, it is a key element to choose appropriate outcomes that ensure the comparability of effects of interventions in ways that minimise bias. We hypothesise that outcome measures in cardiothoracic surgical trials are inconsistent and without standard. Therefore, comparing the relative effectiveness of interventions across studies is problematic. We surmise that cardiothoracic research has focused habitually on the identification of risk factors and on the reduction of adverse outcomes with less consideration of factors that contribute to well being and positive health outcomes (salutogenesis).
  
  
  RESULTS
  We conducted a systematic review of reviews to determine both the type and number of outcomes reported in current cardiothoracic surgery interventional research, in order to identify a list of potential outcomes for a minimum core outcome set (COS). Special focus was placed on outcomes that emphasise salutogenesis. We interpreted salutogenic outcomes as those relating to optimum and/or positive health and well being. We searched Issue 7 (July 2014) of the Cochrane Database of Systematic Reviews. Systematic reviews of randomised trials on non-minimal-invasive off- or on-pump cardiothoracic surgery (elective and emergency, excluding transplants) investigating pre-, intra- or postsurgical interventions related to the outcome of the procedure were eligible for inclusion. We excluded protocols and withdrawn systematic reviews. Two review authors extracted outcome data independently. Unique lists of salutogenically and non-salutogenically focused outcomes were established. 15 systematic reviews involving 371 randomized trials and 58,253 patients were included in this review. Applied definitions of single and composite endpoints varied significantly, and patient-centred, salutogenically focused outcomes were seldom reported. One third of included reviews did not assess patient-centred outcomes at all; all other reviews were unable to perform meta-analyses due to an absence of data or heterogeneity in outcome measures. This compares to 36 non-salutogenically focused outcome domains representing 121 individual non-salutogenically focused outcomes, whereof 50% were assessed only once. Measures of mortality, cerebrovascular complications and hospitalisation were reported most frequently. Two reviews chose a composite endpoint as primary outcome. Pooled analysis of composite endpoints was not possible, as the required data was not reported per patient in all components.
  
  
  CONCLUSIONS
  In cardiothoracic surgical trials, choice and definition of non-salutogenically focused single and composite outcomes are inconsistent. There is an absence of patient centred, salutogenically focused outcome parameters in cardiac trials. We recommend the development of a core outcome set of salutogenically focused and non-salutogenically focused outcomes for cardiothoracic surgical research.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, University Hospital RWTH Aachen, Aachen, Germany.
authors.forename: Carina
authors.initials: C
authors.lastname: Benstoem
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, University Hospital RWTH Aachen, Aachen, Germany.
authors.forename: Ajay
authors.initials: A
authors.lastname: Moza
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, University Hospital RWTH Aachen, Aachen, Germany.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Autschbach
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, University Hospital RWTH Aachen, Aachen, Germany; Department of Anaesthesiology, University Hospital RWTH Aachen, Aachen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Stoppe
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, University Hospital RWTH Aachen, Aachen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Goetzenich
mesh_terms: D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002561:Cerebrovascular Disorders / Q000209:etiology*; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome
references.citation: Circulation. 2011 Dec 6;124(23):e652-735
references.pmid: 22064599
references.citation: Ann Thorac Surg. 2003 Oct;76(4):1094-100
references.pmid: 14529993
references.citation: Value Health. 2014 Nov;17(7):A435
references.pmid: 27201147
references.citation: Trials. 2013 Jan 22;14:21
references.pmid: 23339751
references.citation: Trials. 2007 Nov 26;8:38
references.pmid: 18039364
references.citation: Lancet. 2009 Jul 4;374(9683):86-9
references.pmid: 19525005
references.citation: Cochrane Database Syst Rev. 2014 Jun 25;(6):CD007131
references.pmid: 24963623
references.citation: BMJ. 2010 Feb 15;340:c365
references.pmid: 20156912
references.citation: Cochrane Database Syst Rev. 2011 Jan 19;(1):CD004472
references.pmid: 21249662
references.citation: Midwifery. 2014 Apr;30(4):e151-6
references.pmid: 24290422
references.citation: Trials. 2012 Aug 06;13:132
references.pmid: 22867278
references.citation: Cancer. 1981 Jan 1;47(1):207-14
references.pmid: 7459811
references.citation: Open Med. 2009;3(3):e123-30
references.pmid: 21603045
references.citation: Crit Care. 2007;11(5):R106
references.pmid: 17888156
references.citation: Trials. 2007 Nov 26;8:39
references.pmid: 18039365
references.citation: PLoS One. 2008 Aug 28;3(8):e3081
references.pmid: 18769481
references.citation: Circulation. 1996 Nov 1;94(9 Suppl):II74-80
references.pmid: 8901723
references.citation: Ann Thorac Surg. 2002 Feb;73(2):480-9; discussion 489-90
references.pmid: 11845863