Eligibility criteria for the literature search
| Criteria | Inclusion | Exclusion |
| Publication date | Papers published between 2002 and 2022 | Papers published prior to 2002 |
| Research type | Primary research | Secondary research |
| Study type | Randomised controlled trials (RCT) If no RCT available to consider; Cohort studies Case series>5 patients Case–control studies Meta-analysis Systematic reviews | Case reports Editorials Comments Annotations Letters Commentaries Books and book chapters Updated systematic reviews by same methodology, for example, Cochrane (most recent version will be included) Non-traditional therapies (eg, Chinese medicines) and surgical intervention |
| Publication and study status | Published Completed | Unpublished Ongoing |
| Language | English | Non-English |
| Text availability | Full text available | Full text unavailable |