Simplifying the concept of level of evidence in lay language for all aspects of learners: In brief review

Abstract

The level of evidence is a fundamental structure for assessing the excellence of evidence while making healthcare choices. It assesses medical research according to its structure, credibility, and relevance. The different degrees of proof are frequently represented as a triangle shape, with the most powerful proof on the highest point. The pyramid is divided into two primary parts: refined data (systematic reviews, meta-analyses) that combines information from multiple studies, and raw data (randomized trials, cohort studies, case series) that consists of original research. Systematic evaluations condense results from various investigations on a subject using thorough, replicable approaches. Meta-analyses mathematically integrate information from similar research studies. Case studies provide information about a specific patient. Case-control studies examine the occurrences in separate groups of people who have a particular illness and those who do not. Randomly assigned intervention and control groups are compared in randomized controlled experiments to observe the differences in their outcomes. Cohort studies track groups over a period to investigate connections between factors and results. The upper levels of the pyramid are typically seen as more trustworthy proof because of thorough combination or research structure. However, every level provides valuable information. Recognizing the positive aspects of various research methods enables individuals to assess the credibility of information when making choices related to healthcare.

Keywords

Evidence pyramid / Systematic review / Randomized controlled trial / Bias / Evidence-based practice

References

[1] BaresJ. Stimson library LibGuides: evidence-based practice: evidence pyramid [cited 2023 Oct 31]; Available from: https://amedd.libguides.com/c.php?g=476751&p=3259492.

[2] MuradMH, AsiN, AlsawasM, Alahdab F. New evidence pyramid. Evid based med [cited 2023 Oct 31];21(4):125–7. Available from: https://pubmed.ncbi.nlm.nih.gov/27339128/;2016.

[3] Levels of evidence in medical research [Internet]. [cited 2023 Oct 31]. Available from https://openmd.com/guide/levels-of-evidence.

[4] JamesJ. Academic guides: evidence-based research: levels of evidence pyramid [cited 2023 Oct 31];Available from: https://academicguides.waldenu.edu/library/healthevidence/evidencepyramid.

[5] Grimes DavidA, Schulz Kenneth F. An Overview of Clinical Research: The Lay of the Land [cited 2023 Oct 31].2002.

[6] AromatarisE, Pearson A. The systematic review: an overview [cited 2023 Oct 31];114(3):53–8. Available from: Am J Nurs;2014. https://journals.lww.com/ajnonline/fulltext/2014/03000/the_systematic_review__an_overview.28.aspx.

[7] ElliottJH, SynnotA, TurnerT, et al. Living systematic review: 1. Introduction-the why, what, when, and how [cited 2023 Oct 31];91:23–30. Available from: J Clin Epidemiol;2017. https://research.monash.edu/en/publications/living-systematic-re view-1-introduction-the-why-what-when-and-how.

[8] GopalakrishnanS, Ganeshkumar P. Systematic reviews and meta-analysis: understanding the best evidence in primary healthcare, 2(1):9–14. Available from J Fam Med Prim Care;2013. https://pubmed.ncbi.nlm.nih.gov/24479036.

[9] LeeYH. An Overview of Meta-Analysis for Clinicians [cited 2023 Oct 31];33(2):277–83. Available from:. Korean J Intern Med; 2017. https://typeset.io/papers/an-overviewof-meta-analysis-for-clinicians-2ahk2urwii.

[10] RLO. Case series and cross-sectional studies [Internet]. [cited 2023 Oct 31]. Available from: https://www.nottingham.ac.uk/helmopen/rlos/ebp/case_studies/pa ge_one.html.

[11] Definition of case-control study -NCI dictionary of cancer terms -NCI [Internet]. [cited 2023 Oct 31]. Available from https://www.cancer.gov/publications/dictionaries/cancer-terms/def/case-control-study.

[12] SeddonJM, Gragoudas ES, GlynnRJ, EganKM, AlbertDM, BlitzerPH. Host factors, UV radiation, and risk of uveal melanoma. A case-control study. A M A Archives of Ophthalmology. 1990;108(9):1274–1280.

[13] LischkoAM, SeddonJM, GragoudasES, Egan KM, GlynnRJ. Evaluation of prior primary malignancy as a determinant of uveal melanoma: a case-control study. Ophthalmology. 1989;96(12):1716–1721.

[14] LewallenS, Courtright P. Epidemiology in Practice: Case-Control Studies [cited 2023 Oct 31];11(28):57. Available from:/pmc/articles/PMC1706071/. 1998.

[15] ReesAM, AustinMP, OwenC, Parker G. LibGuides: Quantitative Study Designs: Case Control [cited 2023 Oct 31];166(2–3):254–9. Available from:;2009. https://deakin.libguides.com/quantitative-study-designs/casecontrol.

[16] ReesAM, AustinMP, OwenC, Parker G. Omega-3 deficiency associated with perinatal depression: case control study. Psychiatry Res. 2009;166(2–3):254–259.

[17] Randomized clinical trials | definition of Randomized clinical trials by Medical dictionary [Internet]. [cited 2023 Oct 31]. Available from https://medical-dictionary.thefreedictionary.com/Randomizedþclinicalþtrials.

[18] Randomized controlled trials | PPT [Internet]. [cited 2023 Oct 31]. Available from https://www.slideshare.net/NabeelaBasha/randomized-controlled-trials-68651612.

[19] HaritonE, Locascio JJ. Randomised Controlled Trials -the Gold Standard for Effectiveness Research [cited 2023 Oct 31];125(13):1716–1716. Available from:;2018.

[20] GrimesDA, SchulzKF. Cohort Studies: Marching towards Outcomes [cited 2023 Oct 31];359(9303):341–5. Available from;2002. https://pubmed.ncbi.nlm.nih.gov/11830217/.

[21] BelbasisL, BellouV. Introduction to epidemiological studies [cited 2023 Oct 31];1793:1–6. Available from: Methods Mol Biol;2018. https://pubmed.ncbi.nlm .nih.gov/29876887/.

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