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Dental Hygiene: EBDM #5 Assess

Toolkit for Dental Hygiene

Evidence Pyramid

Tutorial Link

Levels of Evidence

Level of Evidence Strength Grade
Level 1 Studies Strong A
Level 2, 3, or extrapolations from Level 1 Moderate B
Level 4 or extrapolations from Level 2, 3 Limited/Weak C
Level 5 or inconsistent, inconclusive studies from any level Incomplete/Inconsistent D

(Table adapted from CEBM and Forrest, 2009)

Article Types

Clinical Practice Guidelines: Recommendations for clinical care. Usually informed by a knowledge synthesis (systematic review) and clinical expertise.

Systematic Review: Synthesis of evidence (i.e. articles) on a defined topic/question. The group of researchers will evaluate and analyze the evidence to inform clinical practice.

Meta-Analysis: Usually follows a systematic review. Combines the data from multiple (similar) studies to address SR topic/question.

Randomized Controlled Trials: Assesses a specific intervention by comparing two similar groups, with one receiving the intervention and the other not (usually called a placebo). By doing this, researchers can assess the differences attributed to the intervention.

Cohort Studies: Observational studies regarding the association between a specific exposure or risk factor and the development of a clinical condition.

Case Control Studies: Observational studies regarding associations between a specific clinical condition and possible risk factors.

Cross-Sectional Studies: Observational studies that gather information at one point and time on the prevalence of health outcome(s), or exposure(s), or both.

Case Reports: Report of a single patient, or treatment of several patients. There is no research design for case reports. They can be beneficial in identifying new health conditions.

Narrative/Literature Reviews:  Overview of previous studies on a specific topic. Not as rigorous as a knowledge synthesis (i.e. systematic review) and there is no research design.

Editorials: Opinion piece in an academic journal that is not peer reviewed. No research design in an editorial.