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Evidence-Based Practice: A Summary

  1. ASK: Transform the need for information into a clear, answerable question.
  2. FIND: Locate the best evidence available to answer that question.
  3. APPRAISE: Critically evaluate the evidence for its validity and relevance.
  4. APPLY: Combine the critical appraisal with critical expertise, taking into account the patient's unique biology, values, and circumstances.
  5. EVALUATE: Assess the effectiveness and efficiency of steps 1-4 and identify ways to improve the process for future practice.

Evidence-Based Practice: Step-by-Step

ASK USING THE PICO MODEL

A well-built question effectively addresses the most critical aspects of your information need and leads to a precise answer for your clinical inquiry. PICO is an acronym representing the four essential components of a well-formulated clinical question:

  • P = POPULATION: Usually the patient--the recipients or potential beneficiaries of a service or intervention.
  • I = INTERVENTION: The service or planned action to be delivered to the population.
  • C = COMPARISON: An alternative service or action that may or may not achieve similar outcomes.
  • O = OUTCOME: The ways in which the service or action can be measured to determine if it has had the desired effect.

SAMPLE PICO QUESTION: In an adult with knee osteoarthritis, can aquatic exercise reduce pain and disability?

Let's break down the PICO question and design an evidence-based search step-by-step:

  • P = POPULATION:  Adults with knee osteoarthritis
  • I = INTERVENTION: Aquatic exercise
  • C = COMPARISON: (Not explicitly stated, but could be land-based exercise, no exercise, or other types of exercise)
  • O = OUTCOME: Reduction in pain and disability

FIND: DESIGN A SEARCH STRATEGY

Think about the keywords for each of the PICO parts of the clinical question.

SAMPLE PICO QUESTION: In an adult with knee osteoarthritis, can aquatic exercise reduce pain and disability?

PICO CLINICAL SCENARIO POSSIBLE KEYWORDS
PATIENT Adults with knee osteoarthritis

--knee osteoarthritis

--adults with knee osteoarthritis
INTERVENTION Aquatic exercise

--aquatic exercise

--water exercise

--hydrotherapy
COMPARISON Other types of exercise

--land-based exercise

--no exercise

--other types of exercise
OUTCOME Reduced pain/disability

--pain reduction

--decrease in pain

--disability reduction

--improvement in function

Combine Search Terms Using Boolean Operators

  1. Population AND Intervention: ("knee osteoarthritis" OR "adults with knee osteoarthritis") AND ("aquatic exercise" OR "water exercise" OR "hydrotherapy")
  2. Population AND Intervention AND Outcome: ("knee osteoarthritis" OR "adults with knee osteoarthritis") AND ("aquatic exercise" OR "water exercise" OR "hydrotherapy") AND ("pain reduction" OR "decrease in pain" OR "disability reduction" OR "improvement in function")
  3. Population AND Intervention AND Comparison AND Outcome: ("knee osteoarthritis" OR "adults with knee osteoarthritis") AND ("aquatic exercise" OR "water exercise" OR "hydrotherapy") AND ("land-based exercise" OR "no exercise" OR "other types of exercise") AND ("pain reduction" OR "decrease in pain" OR "disability reduction" OR "improvement in function")

HIERARCHY OF EVIDENCE

When starting a search for evidence-based practice research, always look for the highest level of evidence first. If you can't find a meta-analysis on the topic, then look for systematic reviews, randomized controlled trials, controlled comparison or case control studies, and so on. When you search for individual studies in library databases, use the filters on the advanced search screen to narrow your search to the following methodologies when possible.

  • Meta-analysis: Combines data from multiple studies to create a summary statistic
  • Systematic Review: Answers a specific question by finding and describing all published (and if possible, unpublished) work on a topic. It uses detailed methods for a thorough literature search and critical review of individual studies, and combines valid studies using appropriate statistical techniques
  • Randomized Controlled Trial (RCT): Also called a 'randomized clinical trial.' It randomly assigns subjects to groups that receive different interventions to assess their effects
  • Controlled Comparison or Case Control Study: An observational study where the cases have the issue of interest
  • Descriptive Surveys: Describe certain attributes of a population, specify associations between variables, or generate hypotheses to be tested, but do not primarily establish cause-and-effect relationships or test hypotheses
  • Case Studies: Describe a particular service or event, often focusing on unusual aspects or adverse occurrences, and can be exploratory, descriptive, or explanatory

EVALUATION CRITERIA SIMPLIFIED

Imagine you are evaluating a study on a new nursing intervention. Using these following criteria and questions, you can critically evaluate the quality and credibility of research studies in physical therapy.

  • CREDIBILITY (INTERNAL VALIDITY) Check if the study design was solid and the results are trustworthy. 
    • Were patients assigned to either the new intervention or standard treatment?
    • Were patients analyzed in the original groups they were assigned to?
    • Were both groups similar in important factors (for example, age or severity of condition)?
  • TRANSFERABILITY (EXTERNAL VALIDITY) Determine if the study can be applied to other groups or settings.
    • Were the treatment or control groups similar in terms of key factors?
    • Was the comparison done without bias (for example, a blind study)?
    • Are the results valid beyond this specific study?
  • DEPENDABILITY (RELIABILITY) Ensure the results would be consistent if the study were repeated.
    • Were both groups studied treated equally except for the experimental therapy?
    • Did the study follow up with all patients?
    • Do the patients in the study represent the larger population?
  • CONFIRMABILITY (OBJECTIVITY) Make sure the study minimized bias and maintained objectivity.
    • Did key groups (patients, data collectors) know which treatment was given?
    • Was the randomization process hidden to prevent bias?

As a practicing nursing, this is the point at which you would implement the evidence you've gathered through research in your clinical practice. If you're working on an assignment, this could be a component of your role as a student. For instance, if your task involves writing a paper based on research and patient interviews, you'll need to develop a treatment plan that incorporates all the evidence you’ve accumulated so far.

Assess your own performance by asking the following questions:

  1. Did you start the EBP process with an answerable clinical question?
  2. Did you locate the best external evidence during your search for information?
  3. Did you critically appraise the evidence for its validity and potential usefulness?
  4. Did you integrate your critical appraisal with your individual clinical expertise in daily practice?
  5. What were the outcomes of applying the best evidence to your patient(s)?