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Find sources for common nursing course assignments and core competencies

Prescribe Evidence-Based Practice

What is evidence-based medicine?

Evidence based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients" (Sackett et al., 1996, p. 71). Also called evidence-based practice, EBM incorporates the practitioner's expertise and clinical judgement with relevant scientific evidence to honor patients' values and preferences in recommending treatment.

evidence based medicine venn diagram


Sackett, D. L., Rosenberg, W. M., Gray, J. A., Haynes, R. B., & Richardson, W. S. (1996). Evidence based medicine: what it is and what it isn't. BMJ (Clinical research ed.)312(7023), 71–72.,

Dive Deeper

Climb Dartmouth's Evidence Pyramid

Dartmouth's Evidence Pyramid provides a way to visualize both the quality of evidence and the amount of evidence available. For example, systematic reviews are at the top of the pyramid, meaning they are both the highest level of evidence and the least common. As you go down the pyramid, the amount of evidence will increase as the quality of the evidence decreases. Image credit: EBM Pyramid by Trustees of Dartmouth College and Yale University.

Levels of evidence in Evidence based research

Here's another take on the evidence pyramid indicating primary vs. secondary sources and explaining each level.

6-level pyramid of primary and secondary research evidence

Recognize Data Collection Techniques & Tools

Techniques or tools used for gathering research data include:

Qualitative Techniques or Tools Quantitative Techniques or Tools
Interviews: these can be structured, semi-structured or unstructured in-depth sessions with the researcher and a participant. Surveys or questionnaires: which ask the same questions to large numbers of participants or use Likert scales which measure opinions as numerical data.
Focus groups: with several participants discussing a particular topic or a set of questions. Researchers can be facilitators or observers. Observation: which can either involve counting the number of times a specific phenomenon occurs, or the coding of observational data in order to translate it into numbers.
Observations: On-site, in-context or role-play options. Document screening: sourcing numerical data from financial reports or counting word occurrences.
Document analysis: Interrogation of correspondence (letters, diaries, emails etc) or reports. Experiments: testing hypotheses in laboratories, testing cause and effect relationships, through field experiments, or via quasi- or natural experiments.
Oral history or life stories: Remembrances or memories of experiences told to the researcher.  

Differentiate Between Research Methods

Research methods are the strategies, processes or techniques utilized in the collection of data or evidence for analysis in order to uncover new information or create better understanding of a topic. There are different types of research methods which use different tools for data collection.

Qualitative Research down arrow

Gathers data about lived experiences, emotions or behaviors, and the meanings individuals attach to them. It assists in enabling researchers to gain a better understanding of complex concepts, social interactions or cultural phenomena. This type of research is useful in the exploration of how or why things have occurred, interpreting events and describing actions.

Qualitative research refers to any research based on something that is impossible to accurately and precisely measure. It uses methods such as interviews, open-ended questions, participant observations, case studies, focus groups, etc. to identify patterns, themes, and features. These factors cannot easily be reduced to numbers. Qualitative research is common in the social sciences.

Quantitative Research down arrow

Gathers numerical data which can be ranked, measured or categorized through statistical analysis. It assists with uncovering patterns or relationships, and for making generalizations. This type of research is useful for finding out how many, how much, how often, or to what extent. This research based on something that can be accurately and precisely measured might also be referred to as "empirical research."

Pro tip: Statistical analysis in an article usually indicates quantitative research. Check the articles you find to see if some sort of numerical measuring and statistical analysis is present along with the characteristics listed below.

  • Introduction with a statement of background or purpose (what was being studied and why). May review prior studies on the same topic.
  • Description of the design and/or method of the study (the experimental group or sample, control, variables, number of test subjects, test conditions, etc.)
  • Results, or report of the findings (in numeric form as tables, charts, or graphs, etc., often with statistical analysis)
  • Conclusions that can be drawn from the results (may be labeled discussion or significance)
  • Footnotes and/or a bibliography

Mixed Methods Research down arrow

Integrates both Qualitative and Quantitative Research. It provides a holistic approach combining and analyzing the statistical data with deeper contextualized insights. Using Mixed Methods also enables Triangulation, or verification, of the data from two or more sources.

Finding Mixed Methods research in the Databases

"mixed model*" OR "mixed design*" OR "multiple method*" OR multimethod* OR triangulat*

  • PubMed - there are no suitable MeSH terms for mixed methods research in Medline. Search your topic with the following suggested free text keywords using the quotation marks and truncation symbol*:
  • CINAHL - the following Subject Headings may be of use: Multimethod Studies or Triangulation. You can also include in your search the following free text keywords: mixed model*, mixed design*, multiple method*, multimethod*, or triangulat*.

Systematic Review down arrow

Usually focuses on a single, well-defined research question and seeks to comprehensively gather all existing studies that address this research question.

Meta-Analysis down arrow

Takes the results of several existing quantitative studies and analyzes them in a new way. Meta-analysis looks for previously unnoticed patterns or trends among existing study results or seeks to pull out new data from them. Meta-analysis is usually considered another form of quantitative research.

Literature Review down arrow

Also known as a review article, is an article whose sole purpose is to provide an overview of previous important research on a particular topic. Although valuable to researchers, literature reviews are not considered primary research. However, they can help you identify research trends and major articles published on a topic. No new study is conducted in a true literature review.

Take the Study Design Tutorial

Potential Bias in Medical Research

Readers of medical research studies should be aware of the potential for bias and should critically evaluate the study design and methodology before drawing any conclusions from the results.

Bias in medical research studies can occur at any stage of the research process, from the design of the study to the interpretation of the results. It can arise from a variety of factors, including the researchers' own beliefs and expectations, the way the study is conducted, and the characteristics of the study participants.

Here are some of the most common types of bias in medical research studies:

  • Selection bias: This occurs when the study participants are not representative of the population of interest. For example, a study that only includes people who are willing to participate may not accurately reflect the experiences of the general population.
  • Information bias: This occurs when there are errors in the measurement of the exposure or outcome of interest. For example, if researchers are not blinded to the treatment assignment, they may subconsciously collect or interpret data in a way that favors their preferred treatment.
  • Performance bias: This occurs when there are differences in the way that the treatment or intervention is delivered to different groups of participants. For example, if researchers are aware of the treatment assignment, they may provide more intensive care to the group receiving the new treatment.
  • Attrition bias: This occurs when participants drop out of the study before it is completed. If the dropouts are not representative of the participants who remain in the study, the results may be biased.
  • Reporting bias: This occurs when researchers selectively publish or report the results of their studies. For example, researchers may be more likely to publish studies with positive results, which can give the impression that the treatment or intervention is more effective than it actually is.

Bias can have a significant impact on the results of medical research studies. It can lead to overestimates or underestimates of the true effect of a treatment or intervention, and it can make it difficult to compare the results of different studies.

Here are some things that researchers can do to reduce bias in their studies:

  • Use randomization to assign participants to treatment groups.
  • Blind researchers to the treatment assignment.
  • Use standardized methods for collecting and measuring data.
  • Track and report all dropouts.
  • Publish all results, regardless of their statistical significance.

Understand Statistical Significance

Tenny & Abdelgawad (2022) explain statistical significance in medical research in their peer-reviewed article. Statistical significance tells us how likely it is that a study's findings are true, considering the acceptable level of uncertainty. Breaking down a study's design helps us grasp this concept better. Read their work to fully understand the importance of a study's statistical claims.


Tenny, S., & Abdelgawad, I. (2022). Statistical significance. In StatPearls. StatPearls Publishing.