| Date | Event | Description |
|---|---|---|
| 1 March 2019 | New citation required but conclusions have not changed | Updated. Conclusions unchanged. |
| 1 March 2019 | New search has been performed | New search. 25 new studies included. 'Summary of findings' table added. Four new co‐authors added, Gill Norman, Zhenmi Liu, Jo Dumville and Laura Chiverton. |
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