Practice recommendations1,2
|
Grade |
Level |
Type of evidence |
|
A |
Ia |
Evidence obtained from a well designed randomised controlled trial of appropriate size (T1) |
|
B |
Ib |
Evidence obtained from a well designed controlled trial without randomisation (T2, T3) |
|
B |
IIa |
Evidence obtained from a well designed controlled observational study e.g. cohort, case-control or cross-sectional studies. (Also include studies using purely qualitative methods) (O1, O2) |
|
C |
IIb |
Evidence obtained from a well designed uncontrolled observational study (O3, O4) |
|
C |
III |
Evidence obtained from studies that are case study or case series (O5, O6) |
Click here to open
References
- This classification is based on the Bandolier system adapted to include the Centre for Reviews and Dissemination. Systematic Reviews: CRD's Guidance for Undertaking Reviews in Health Care, 2009 Centre for Reviews and Dissemination, University of York. [PDF from York University]
- Weaver N, Williams JL, Weightman AL, Kitcher HN, Temple JM, Jones P, Palmer S. Taking STOX: developing a cross disciplinary methodology for systematic reviews of research on the built environment and the health of the public. Journal of Epidemiology and Community Health. 2002;56(1):48-55. [Pubmed]