CRD Summary: This generally well-conducted review concluded that, compared with placebo, N-acetylcysteine medication was associated with a reduction in post-surgery atrial fibrillation in patients undergoing cardiothoracic surgery, but not in other outcomes of post-surgery complications. This conclusion is likely to be reliable.

CRD Commentary: This review's inclusion criteria were clear. Several relevant databases were searched. Efforts were made to find published studies, but not unpublished studies, thereby introducing the potential for publication bias. Funnel plots further suggested the possibility of publication bias, but Egger's weighted regression statistics did not support the presence of publication bias. The authors did not state whether language restrictions were applied in the search, which made it difficult to assess the risk of language bias. The review process was carried out with sufficient attempts to minimise errors and bias. Adequate details of the primary studies were provided. Relevant criteria were used to examine the study quality; the result of quality assessment was not fully reported. Statistical heterogeneity was assessed and appropriate statistical methods were used to pool the results. This review was generally well conducted and the authors' conclusions are likely to be reliable.