Symbols | |
![]() | Canada |
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![]() | OTC |
* | Liquid contains alcohol |
![]() | Photo Guide |
![]() | Do not crush |
![]() | Off-label use |
The following leveling system is from Evidence-Based Practice in Nursing and Healthcare: A Guide to Best Practice (2nd ed.) by Bernadette Mazurek Melnyk and Ellen Fineout-Overholt.
Level I: | Evidence from a systematic review or meta-analysis of all relevant randomized controlled trials (RCTs) |
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Level II: | Evidence obtained from well-designed RCTs |
Level III: | Evidence obtained from well-designed controlled trials without randomization |
Level IV: | Evidence from well-designed case-control and cohort studies |
Level V: | Evidence from systematic reviews of descriptive and qualitative studies |
Level VI: | Evidence from single descriptive or qualitative studies |
Level VII: | Evidence from the opinion of authorities and/or reports of expert committees |
Modified from Guyatt, G. & Rennie, D. (2002). Users' Guides to the Medical Literature. Chicago, IL: American Medical Association; Harris, R.P., Hefland, M., Woolf, S.H., Lohr, K.N., Mulrow, C.D., Teutsch, S.M., et al. (2001). Current Methods of the U.S. Preventive Services Task Force: A Review of the Process. American Journal of Preventive Medicine, 20, 21-35.