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Nursing & Health Sciences Research

Evidence-Based Research

Nursing research can feel intimidating and confusing, so these resources were created to guide you through the process. Start by watching the video below to learn the differences between evidence-based practice articles and scholarly, research articles. You may also download the comparison chart to save as a quick reference. Knowing the differences will help you as you search for and evaluate nursing research.

Start your search in one or more of these databases:

In the search box, enter in the nursing topic that you are interested in. Then, include the phrase "best practice" or "evidence-based", keeping the quotation marks around the words. Best practices are informed by evidence, so try using both phrases to see how they affect your search results. The phrase "best practice" may not show up in the article title, so be sure to read the abstract before ruling out an article. 

You can also change the publication date range so that only articles published in the last five years are shown.

If you are struggling to tell the difference between evidence-based and scholarly research articles, check out the video in the Getting Started tab.

EBSCO search screen showing to use the publication date limiter on the left hand side

It can be challenging to pick a topic from such a huge pool of possibilities. It is important to pick a topic that interests you because you will be spending a lot of time researching and writing about it! 

Check out the table below for ideas of selecting an evidence-based practice problem. After selecting your broad topic, create a concept map to narrow down your topic and develop your PICO question.

Sources of Evidence-Based Practice Problems
Triggers Sources of Evidence-Based Practice Problems
Problem-focused Financial concerns
Evidence for current practice questioned
Quality concern (efficiency, effectiveness, timeliness, equity, patient-centeredness)
Safety or risk management concerns
Unsatisfactory patient, staff, or organizational outcomes
Variations in practice compared with external organizations
Variations in practice within the setting
Knowledge-focused New sources of evidence
Changes in standards or guidelines
New philosophies of care
New information provided by organizational standards committees

Adapted from Johns Hopkins Evidence-Based Practice for Nurses and Healthcare Professionals (4th ed., p. 81), by D. Dang, S. L. Dearholt, K. Bissett, J. Ascenzi, and M. Whalen, 2021, Sigma Theta Tau International Honor Society of Nursing (https://ebookcentral.proquest.com/lib/ras/reader.action?docID=6677828&ppg=1). Copyright 2022 by Sigma Theta Tau International Honor Society of Nursing.

Hierarchy of Evidence Guide

Research Evidence

Level I

  • Experimental study, randomized controlled trial (RCT)
  • Explanatory mixed methods design that includes only a Level I quantitative study
  • Systematic review of RCTs, with or without meta-analysis

Level II

  • Quasi-experimental Study
  • Explanatory mixed methods design that includes only a Level II quantitative study
  • Systematic review of a combination of RCTs and quasi-experimental, or quasi-experimental studies only, with or without meta-analysis

Level III

  • Non-experimental study
  • Systematic review of a combination of RCTs, quasi-experimental and nonexperimental studies, or nonexperimental studies only, with or without meta-analysis
  • Exploratory, convergent, or multiphasic mixed methods studies
  • Explanatory mixed methods design that includes only a Level III quantitative study
  • Qualitative study
  • Systematic review of qualitative studies, with or without meta-synthesis

Nonresearch Evidence

Level IV

Opinion of respected authorities and/or nationally recognized expert committees or consensus panels based on scientific evidence. Includes:

  • Clinical practice guidelines
  • Consensus panels/position statements

Level V
Based on experiential and non-research evidence. Includes:

  • Scoping reviews
  • Integrative reviews
  • Literature reviews
  • Quality improvement, program or financial evaluation
  • Case reports
  • Opinion of nationally recognized expert(s) based on experiential evidence

Adapted from Johns Hopkins Evidence-Based Practice for Nurses and Healthcare Professionals (4th ed., p. 296), by D. Dang, S. L. Dearholt, K. Bissett, J. Ascenzi, and M. Whalen, 2021, Sigma Theta Tau International Honor Society of Nursing (https://ebookcentral.proquest.com/lib/ras/reader.action?docID=6677828&ppg=1). Copyright 2022 by Sigma Theta Tau International Honor Society of Nursing.

Visit the Qualitative and Quantitative tabs to watch video tutorials of how to specifically search for that type of article in the online library databases.


Search Strategies

  • Do not enter your entire PICO(T) into the search box
  • Identify two to three keywords at most for your first search
  • Start broad and then limit your results using limiters, such as:
    • Scholarly (Peer Reviewed) Journals
    • Publication Date Range
    • Subjects
  • If you have too few results, take out a search term
  • Make sure you read the abstract and do not make a decision on an article only by its title
  • Create a free MyEBSCOhost account so you can save articles to a folder for access later
  • Start your searching early so that you have time to request articles through interlibrary loan
  • Make an appointment with the School of Nursing librarian for research help
An Overview of the Research Designs of Qualitative Research
Content Phenomenology Ethnography Grounded Theory Historical Method Case Study
Sample Individuals or groups Groups or individuals in a culture although more likely to involve groups Individuals or groups Sources of historical significance Single person or single problem, small group or institution
Example of types of instruments/tools used Interviews and descriptions, observation Observation and documentation of daily life – the investigator immerses themselves in the culture or group being studied Observation, fieldnotes, intensive interviews, review of documents, analysis of literature and research on the topic, memo-writing Historical material such as letters, memos, diaries, handwritten materials, old books, newspapers, books, audio or videotapes, government records, archives Interviews, observation, records, historical documents and statements
Ethics permission Essential Essential Essential Essential Essential

Adapted from "A Nurses’ Guide to Qualitative Research," by R. Ingham-Broomfield, 2015, Australian Journal Of Advanced Nursing, 32(3), p. 39 (https://www.ajan.com.au/archive/Vol32/Issue3/4Broomfield.pdf). Copyright 2015 by the Australian Nursing & Midwifery Federation.

Quantitative Research - Approaches to Experimental Design
Type of Design Key Focus & Control of Variables Intervention Applied? Example Common Study Designs
Descriptive Observational; Describe "what is"; Variables not controlled No A description of teenagers' attitudes towards smoking Comparative descriptive designs; Cross-sectional designs; Longitudinal designs
Correlational Explores and observes relationships among variables; Variables not controlled No A study of the relationship between IQ and clinical depression Descriptive correlation designs; predictive designs; model-testing designs
Quasi-Experimental Tests for causality with suboptimal variable control; Independent variable not manipulated Yes A study of the effect of an after school physical activity program on childhood obesity rates Pre- and Post-test designs; Post-test only designs; Interrupted time-series designs
Experimental Tests for causality with optimal variable control; Independent variable is manipulated Yes A study of the effects of a new diet treatment plan on insulin levels in diabetics Classic experimental designs; Randomized designs; Crossover designs; Nested designs

Adapted from Research Ready: Quantitative Approaches, by Center for Innovation in Research on Teaching, n.d., Grand Canyon University (https://cirt.gcu.edu/research/develop/research_ready/quantresearch/6).

Validity: The extent to which a variable or intervention measures what it is supposed to measure or accomplishes what it is supposed to accomplish. 

Internal validity refers specifically to whether an experimental treatment/condition makes a difference or not, and whether there is sufficient evidence to support the claim.

External validity refers to the generalizability of the treatment/condition outcomes.

Factors which jeopardize internal validity

  • History--the specific events which occur between the first and second measurement.
  • Maturation--the processes within subjects which act as a function of the passage of time. i.e. if the project lasts a few years, most participants may improve their performance regardless of treatment.
  • Testing--the effects of taking a test on the outcomes of taking a second test.
  • Instrumentation--the changes in the instrument, observers, or scorers which may produce changes in outcomes.
  • Statistical regression--It is also known as regression to the mean. This threat is caused by the selection of subjects on the basis of extreme scores or characteristics. Give me forty worst students and I guarantee that they will show immediate improvement right after my treatment.
  • Selection of subjects--the biases which may result in selection of comparison groups. Randomization (Random assignment) of group membership is a counter-attack against this threat. However, when the sample size is small, randomization may lead to Simpson Paradox.
  • Experimental mortality--the loss of subjects. For example, in a Web-based instruction project entitled Eruditio, it started with 161 subjects and only 95 of them completed the entire module. Those who stayed in the project all the way to end may be more motivated to learn and thus achieved higher performance.
  • Selection-maturation interaction--the selection of comparison groups and maturation interacting which may lead to confounding outcomes, and erroneous interpretation that the treatment caused the effect.
  • John Henry effect--John Henry was a worker who outperformed a machine under an experimental setting because he was aware that his performance was compared with that of a machine.

Factors which jeopardize external validity

  • Reactive or interaction effect of testing--a pretest might increase or decrease a subject's sensitivity or responsiveness to the experimental variable.
  • Interaction effects of selection biases and the experimental variable
  • Reactive effects of experimental arrangements--it is difficult to generalize to non-experimental settings if the effect was attributable to the experimental arrangement of the research.
  • Multiple treatment interference--as multiple treatments are given to the same subjects, it is difficult to control for the effects of prior treatments.

(Content credit: UW-Madison Ebling Library https://researchguides.library.wisc.edu/nursing)