Levels of Evidence in Richardson

Subject: Science
Type: Synthesis Essay
Pages: 2
Word count: 743
Topics: Observation, Medicine, Scientific Method

The levels of evidence for cause-probing questions

Due to a large amount of information now available on the Internet, it has become necessary to test the factuality of any information used in research. To do this, any claim on data is tested to acquire evidence to prove its validity. This paper discusses the levels of evidence of three articles used in a previous paper. To determine the level of evidence of each article, the hierarchy of designs presented by D.F. Polit and C.T. Beck (2012) is used.

The levels of evidence are a grading system used to rank the validity and effectiveness of scientific publications based on how much information from studies and articles the publication used. The levels of evidence also act as an indicator of how strongly a study should be recommended for research.

There are seven levels of evidence with level I being the most valid and effective (Polit & Beck, 2012). For a study to qualify as a first level of evidence there must have been a proper meta-analysis of at least three randomized clinical trials (RCTs) and nonrandomized trials (Winona State University, 2017). Level II needs only one RCT and one nonrandomized trial. The next level requires a systematic review of observational studies on the same topic as the study while level IV only requires the analysis of one correlating study (Hoke, 2014). The next two levels, level V and VI, require the analysis of descriptive studies; multiple studies in level V and one study in level VI. The last level, level VII, needs only the expert opinion of authoritative figures in that scientific field.

Determining the levels of evidence

The three articles under review were all used to seek a solution to the problem of the health risks of ionizing radiations in healthcare facilities.

In Risks and Health Effects in Operating Room Personnel (van den Berg-Dijkmeijer, Frings-Dresen, & Sluiter, 2011), van den Berg-Dijkmeijer, Frings-Dresen, and Sluiter discuss the factors in the operating room that could possibly have negative effects on the medical staff in the operating room. One of these factors was radiation explaining the usage of this article to seek a solution to the aforementioned problem. When describing the methodology used, the authors state that they systematically reviewed 23 correlating articles in Pubmed which included 11 case studies on the topic (van den Berg-Dijkmeijer, Frings-Dresen, & Sluiter, 2011). Due to the presence of over three case studies being analyzed, this article achieves the first level of evidence.

The next article used was Ionizing Radiation: Promoting Safety for Patients, Visitors, and Staff (Hart, 2006). In this article, Hart discusses the types of ionizing radiation, the risk it holds to the human body as it is used to treat cancer patients and some solutions to reduce unnecessary exposure to nurses. In her paper, Hart uses the results obtained from over ten observational studies on the same topic of radiation. Hart lists the consequences of radiation as obtained from the review of multiple studies. However, nowhere in her paper does Hart systematically review past clinical trials were done on the topic. With all this in mind, it can be concluded that the article was written using the third level of evidence.

Lastly is the article Radiation Exposure and Diagnostic Imaging (Richardson, 2010). In it, Richardson focuses on the need to increase awareness on the risk to clinicians from radiation treatments, the current radiation practices used and solutions to reduce this harmful radiation exposure. In the abstract, it is mentioned that the data source used was evidence-based literature in biological and health-related fields (Richardson, 2010). No mention of clinical trials was made leading to this article falling on level five of the hierarchy. 


Gauging the validity and effectiveness of a scientific article is important to ensure it can be used as a reliable source. One way of doing this is to determine the level of evidence it used according to the evidence hierarchy of designs (Polit & Beck, 2012). The first article graded was Risks and Health Effects in Operating Room Personnel (van den Berg-Dijkmeijer, Frings-Dresen, & Sluiter, 2011) and was concluded to be at level one. The next article by Hart (2006) was determined to have used level III evidence while the third article by Richardson (2010) fell into the fifth level.

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  1. Hart, S. (2006). Ionising Radiation: Promoting Safety for Patients, Visitors, and Staff. Nursing Standard, 20 (47), 47-58.
  2. Hoke, T. M. (2014). Improving Outcomes Through Patient Empowerment at Transition of Care: A Fall Prevention Program for Stroke Survivors. Doctoral Thesis, The Unversity of Arizona, College of Nursing.
  3. Polit, D. F., & Beck, C. T. (2012). Nursing Research: Generating and Assessing Evidence for Nursing Practice (9th Edition ed.). Philadelphia: Lippincott Williams & Wilkins.
  4. Richardson, L. (2010). Radiation Exposure and Diagnostic Imaging. Journal of the American Academy of Nurse Practitioners, 22 (4), 178-85.
  5. van den Berg-Dijkmeijer, M., Frings-Dresen, M., & Sluiter, J. (2011). Risks and health effects in operating room personnel. Work, 39 (3), 331-344.
  6. Winona State University. (2017, February 2). Evidence Based Practice Toolkit. Retrieved April 17, 2017, from Darrell W. Krueger Library: http://libguides.winona.edu/c.php?g=11614&p=61584
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