title: Research and statistics: validity hierarchy for study design and study type.
authors.affiliation: Division of General Pediatrics and Adolescent Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Carisa
authors.initials: C
authors.lastname: Perry-Parrish
authors.forename: Rachel
authors.initials: R
authors.lastname: Dodge
mesh_terms: D001291:Attitude of Health Personnel; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D012106:Research / Q000706:statistics & numerical data*; D012107:Research Design; D016896:Treatment Outcome