A Systematic Review and Meta-Analysis of Studies of Preoperative Aspirin on Bleeding and Cardiovascular Outcomes of Patients Undergoing Coronary Artery Bypass Surgery: A Comparison of Bayesian and Classical Approaches

Abstract

<p> Meta-analysis is a statistical method to summarize the overall evidence of effects on intervention by systematically combining outcomes from available studies in the literature which are homogeneous in research methodology and research interest. The objective of this project is to evaluate the treatment effects of preoperative aspirin on bleeding and other cardiovascular outcomes from 11 randomized control trials (RCT) and 19 observational (non-RCT) studies. Both Bayesian meta-analysis and classical (frequentist) meta-analysis were applied to continuous and binary outcomes, and the results were compared.</p> <p> The robustness of the Bayesian approach is assessed by examining the performances of different likelihood functions and priors. We also discuss strategies on dealing with zero-event studies for binary outcomes, and the implementation of multiple imputation (MI) technique to missing data for continuous outcomes.</p> <p> Most results of primary analysis agree between the Bayesian and classical approaches. We suggest that the final conclusion of a meta-analysis should be based on the comparison of the results from both Bayesian and classical approaches.</p>