This realist review has relatively clear inclusion criteria and the searches are comprehensive. They report on a broad range of topics in the review and it contains an-in-depth discussion of included studies. However, the review has a few major limitations. English language studies only were includable so it's possible may language bias occurred. Also, it is not clear if the authors did independent screening and independent data extraction by at least two reviewers. Finally, the quality criteria for assessing studies were not reported and no details of the assessment were reported either.