Evaluating Outcomes Used in Cardiothoracic Surgery Intervention Based Research - A Systematic Review of Reviews to Develop a Core Outcome Set

Background: Comparing relative effectiveness of interventions on specific outcomes across studies is problematic due to the inconsistency in choice and definition of outcome measures used by researchers. In cardiothoracic surgery, 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).

Methods: We conducted a systematic review of reviews to determine the type and number of outcomes reported in current cardiothoracic surgery intervention based research to identify a list of potential outcomes for a minimum core outcome set (COS). Special focus was laid on outcomes that emphasize salutogenesis. We searched Issue 7 (July 14) of the Cochrane Database of Systematic Reviews. Systematic reviews of randomized 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 We excluded protocols and withdrawn systematic reviews.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.

Results: In the 15 included systematic reviews (363 RCTs, n = 57,482) patient-centered, one third did not assess salutogenically-focused outcomes at all, two third did intend but were not able to perform meta-analyses due to absence of data, heterogeneity in outcome measurement and reporting. This compares to 36 non-salutogenically-focused outcome categories that were identified representing 112 individual non-salutogenically-focused outcomes. Measures of mortality, cerebrovascular complications and outcomes relating to hospitalisation were reported most frequently. Applied definitions were inconsistent for all categories. Composite endpoints varied significantly, were not validated with regard to combined components and the population under investigation.

Conclusion: There is an absence of salutogenically-focused outcome parameters in cardiothoracic surgery intervention based research. Choice and definition of non-salutogenically-focused single and composite outcomes are inconsistent. We recommend the development of a core outcome set of salutogenically-focused and non-salutogenically-focused outcomes for intervention-based cardiothoracic surgical research.