CRD Summary: The authors concluded that selenium supplements cannot currently be recommended for the prevention of cardiovascular disease. Although the authors’ conclusion appears to follow from the results presented, their limited search makes it difficult to confidently assess the reliability of the review.

CRD Commentary: The review question was stated clearly. Limiting the search to two databases might have resulted in the omission of other relevant studies. No language restrictions were applied but there were no attempts to minimise publication bias. Appropriate methods were used to minimise reviewer error and bias during the study selection and data extraction processes. Only RCTs were included, and validity was assessed and some aspects of it reported. The studies were combined using meta-analysis and the influence of individual studies was examined. Although a forest plot showed that none of the studies found any significant difference between the treatments, there was no formal assessment of statistical heterogeneity. The authors’ conclusion appears to follow from the results presented, but their limited search makes it difficult to confidently assess the reliability of the review.