Table 1 Hierarchy of evidence (Lloyd-Smith 1997)
From: The postural effects of load carriage on young people – a systematic review
Level of evidence | Study design |
|---|---|
1a | Meta-analysis of randomised controlled trials |
1b | One individual randomised controlled study |
2a | One well-designed, non randomised controlled study |
2b | Well – designed quasi-experimental study |
3 | Non-experimental descriptive studies-comparative/ case studies |
4 | Respectable opinion |