title: Levels of evidence: further insight on Gugiu and Gugiu.
authors.affiliation: Biometry Research Group, National Cancer Institute, Bethesda, MD 20892, USA. vance917@gmail.com
authors.forename: Vance W
authors.initials: VW
authors.lastname: Berger
authors.forename: Diana
authors.initials: D
authors.lastname: Knoll
mesh_terms: D015984:Causality; D003627:Data Interpretation, Statistical; D019317:Evidence-Based Medicine; D017408:Guidelines as Topic; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D012107:Research Design