Skip to Main Content
University of Detroit Mercy logo

Nursing

evidence based medicine pyramid
Page contains:
  • information for constructing PICOT questions
  • best study designs for question types (i.e. intervention, diagnosis, prognosis, etc.)
  • evidence based practice filters in PubMed
  • handouts for finding nursing research
  • levels (hierarchy) of evidence information
  • tutorials to assist with identifying evidence based practice articles and identifying individual (single) research studies
  • resources for analyzing research studies
  • links to practice guidelines resources

Using a PICO/T Question for Searching the Literature

PICO/T is a way to format a research question. It can also get you started with keywords for your literature search

P = Population of interest (consider age, gender, race, ethnicity, disease process, comorbidities)

I = Intervention (exposure to disease, prognostic factor A, risk behaviors, treatment, what do you want to do for this population? what could be done better?)

C = Comparison of interest (no comparison, placebo, prognostic factor B, absence of risk behavior, other treatments - "gold standard")

O = Outcome of interest (what result are you looking for? risk of disease, rate of occurrence of adverse outcomes like illness, comorbidity, or death)

T = Time (how long does it take to demonstrate an outcome? how long are participants observed? - if relevant to your question)

s = Study types (if relevant to your question)

Examples

1. P = menopausal women;  I = cranberry juice; C = no cranberry juice; O = incidence of UTI

In menopausal women, does drinking 1 cup of cranberry juice daily versus not drinking any cranberry juice lower the incidence of urinary tract infections?

Initial Keywords: menopause, cranberry juice, urinary tract infections

2. P = adults with arthritis; I = tomatoes; C = No comparison; O = increased joint pain

Do tomatoes worsen joint pain in adults with arthritis?

Initial Keywords: tomatoes, arthritis, pain

Reference:

Godshall, M. (2016). Fast facts for evidence-based practice in nursing (2nd ed.). Springer Publishing Company. DOI 10.1891/9780826194077

Best Study Designs for Question Type

Matching questions types  to study design

EBP Filters in PubMed

Methods for Limiting to Evidence Based Practice:

1. Filter by Article Types / Publication Types: (left column - see PubMed filters handout above)

Clinical Study: automatically includes Clinical Trial, Controlled Clinical Trial, Randomized Clinical Trial, Observational Study

Comparative Study = comparison of outcomes, results, etc. for different techniques, therapeutic approaches or other inputs.

Meta-Analysis = (multi-study) - studies using a quantitative method of combining the results of independent studies and synthesizing summaries and conclusions which may be used to evaluate therapeutic effectiveness. 

Multicenter Study = a study executed by several institutions

Systematic Reviews = (multi-study) - review of primary literature that attempts to identify, appraise, and synthesize all empirical evidence that meets specified eligibility criteria to answer a given research question. Systematic Reviews are NOT the same as Literature Reviews. Literature Reviews are NOT EBP.

Evaluation Study = studies determining the effectiveness of processes, personnel, and equipment

Validation Study = research using processes by which the reliability and relevance of a procedure for a specific purpose are established

Practice Guidelines: most are EBP, but some are still opinion-based. You will need to review the guideline to ensure it is EBP.


2. Include study type as a search term: (e.g. xxxx AND epidemiologic studies)

Epidemiologic Studies - Use for studies that examine associations, hypothesized causal relations. They are usually concerned with identifying or measuring the effects of risk factors or exposures.

  • Search term automatically includes: Cohort Studies, Longitudinal Studies, Prospective/Retrospective Studies, Case Control Studies, Cross Sectional Studies.

Qualitative Research - can also use the following search terms to capture the various types of qualitative studies:

  • focus groups OR phenomenology OR ethnography OR nursing methodology research OR narration OR thematic analysis 

Finding Nursing-specific Research

The handout below demonstrates several methods for targeting nursing research:
  • limiting to Nursing Journals in CINAHL
  • including titles of nursing journals in a PubMed search strategy
  • search using author affiliation in CINAHL and PubMed
    • look for Colleges or Departments of Nursing. Both PubMed and CINAHL include functionality that searches the Affiliation field; search using the term nursing.

Identifying Evidence based Practice and Single Studies

How do you know if an article is evidenced based practice
See the tutorial below
Need to identify single / individual studies from systematic reviews and meta-analysis? 
See the tutorial below

Levels (Hierarchy) of Evidence

Photo by Alpha Stock Images - Creative Commons 3 - CC BY-SA 3.0
Evidence board

Level I:

Meta-analysis; Systematic Reviews of Randomized Controlled Trials (RCT)

Level II:

Randomized Controlled Trial (RCT)

Level III:

Quasi-experimental Studies (Controlled trials without randomization)

Level IV:

Cohort Studies (epidemiologic); Case-controlled Studies (epidemiologic)

Level V:

Systematic reviews of Descriptive Studies; Systematic reviews of Qualitative studies (meta-synthesis); Correlational Studies

Level VI:

Single Descriptive Study; Single Qualitative Study; Case Series Studies; Case Reports; Concept Analysis

Level VII:

Opinion; Reports of Expert Committees; Manufacturer's Recommendations; Traditional Literature Reviews

Based on: Schmidt, N. A., & Brown, J. (2019). Evidence-Based practice for nurses: Appraisal and application of research (4th ed.). Jones & Bartlett Learning.

Resources for Analyzing and Appraising a Research Study

magnifying glass

Finding Nursing Practice Guidelines