"Evidence-based practice in public health involves using the best available evidence to make informed public health practice decisions" (Evidence-Based Practice for Public Health). It is an integration of science-based interventions with community preferences for improving population health. Key elements of evidence-based public health include:
Jacobs JA, Jones E, Gabella BA, Spring B, Brownson RC. (2012). Tools for Implementing an Evidence-Based Approach in Public Health Practice. Preventing Chronic Disease, 9, 110324. DOI: http://dx.doi.org/10.5888/pcd9.110324
Systematic Reviews usually involve a detailed and comprehensive plan and search strategy, with the goal of reducing bias by identifying, appraising, and synthesizing all relevant studies on a particular topic. They usually focus on a clinical topic and answer a specific question.¹
A Meta Analysis uses statistical techniques to combine the findings from several quantitative studies. The statistical methods objectively evaluate, synthesize, and summarize the results. A meta analysis may be conducted as part of a systematic review.¹
Randomized Controlled Trials (RCTs) are prospective studies that measure the effectiveness of a new intervention or treatment. Randomization reduces bias and provides a rigorous tool to examine cause-effect relationships between an intervention and an outcome. This is because the act of randomization balances participant characteristics (both observed and unobserved) between the groups allowing attribution of any differences in outcome to the study intervention.²
¹Uman L. S. (2011). Systematic reviews and meta-analyses. Journal of the Canadian Academy of Child and Adolescent Psychiatry = Journal de l'Academie canadienne de psychiatrie de l'enfant et de l'adolescent, 20(1), 57–59.
²Hariton, E., & Locascio, J. J. (2018). Randomised controlled trials - the gold standard for effectiveness research: Study design: randomised controlled trials. BJOG : an international journal of obstetrics and gynaecology, 125(13), 1716. https://doi.org/10.1111/1471-0528.15199
CFCF [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)] Retrieved from https://commons.wikimedia.org/wiki/File:Research_design_and_evidence.svg
Evidence hierarchies rank different research or evaluation study designs based on the rigor of their research methods. Usually, the greater the number of high-quality studies included in the analysis and the more rigorous the research design, the higher the evidence rating in the hierarchy. Research with the strongest indication of effectiveness, such as systematic reviews, meta analyses, and randomized controlled trials (RCTs), are usually at the top of evidence hierarchies.
FACS Insights, Analysis and Research, NSW department of Communities and Justice. (2020). What is an Evidence Hierarchy? [Fact sheet]. https://www.facs.nsw.gov.au/__data/assets/pdf_file/0007/789163/What-is-an-Evidence-Hierarchy.pdf