French good practice guidelines for medical and occupational surveillance of the low back pain risk among workers exposed to manual handling of loads

Table 1 Recommendation grading (according to the French National Health Authority, 2010 [28])

Level of scientific proof provided by the literature (for clinical studies)	Recommendation grading
Level 1	Level A
- High-power randomised comparative studies	Scientific proof established
- Meta-analysis of randomised comparative studies
- Decision analysis based on well-conducted studies
Level 2	Level B
- Low-power randomised comparative studies	Scientific proof presumed
- Well-conducted non-randomised comparative studies	Scientific proof presumed
Level 3	Level C
- Case–control studies	Low level of proof
Level 4	Level D
- Comparative studies with major bias	Expert consensus
- Retrospective studies
- Case series

In the absence of studies, guidelines are based on a consensus between working party experts after consulting the peer review group

ISSN: 2052-4374