Levels of Evidence
This report focuses on the extent to which recommendations were supported by Level 1 or 2 evidence. NSW Health has published the following definitions for grading evidence:
| Level 1 | Systematic review of
randomised controlled trials/large multi-centre trial |
| Level 2 | One or more randomised
controlled trials |
| Level 3 | Controlled trials without
randomisation; cohort, case-control, analytic studies; multiple
time series, before and after studies (preferably from more than
one centre or research group) |
| Level 4 | Other observational studies |
| Level 5 | Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees. |