Physical Therapy

Evidence-Based Practice includes:

• best evidence
• clinician knowledge and skills 
• the patient's wants and needs

The best evidence is determined through evaluation and critical appraisal to determine the level of evidence and quality of the study. The clinical question will determine which type of study to search for. The highest level of evidence (level 1) is the best evidence, but if there is no level 1 evidence, then the best evidence is level 2, and so on. For studies of interventions, first search for a clinical practice guideline, then systematic review, then randomized control trials, and then proceed down the levels. For studies of diagnostic tests, cohort studies should be searched for first. For prognostic questions, search for observational studies of association which include cohort studies and case-control studies.

Critically appraise the study by

• determining the applicability of the study
• determining the quality of the study
• interpreting the results of the study
• summarizing the clinical bottom line for the study

Fetters L, Tilon J. Evidence Based Physical Therapy. F.A. Davis; 2019.

Use Oxford's Centre for Evidence-Based Medicine (CEBM) 2011 Levels of Evidence to determine the hierarchy of the most likely best evidence. 

Download your own copy with the link below.

Academic papers may be difficult to read and interpret. Use the resources below to gain skills in reading academic writing.

As part of your research, you may need to create an evidence table. Evidence tables organize, describe, and present the strengths and rationale for the evidence you are including in a project.

For each piece of evidence you will include:

• Condition
• Study Design
• Author, Year
• N (Number of Subjects)
• Statistically Significant?
• Quality of Study
• Magnitude of Benefit
• Absolute Risk Reduction
• Number Needed to Treat
• Comments

Critically appraised topics (CATs) are very brief reviews that summarize the current best evidence on an intervention or diagnosis.

 CATs are quick, compared to other reviews, and they should still follow these search steps:

1. Define a clear, concise, and focused question – use a search framework such as PICO to help you with this.
2. Develop a search strategy – identify search terms and how to combine them, determine filters to use for inclusion/exclusion criteria, and select appropriate databases.
3. Identify the relevant studies that help answer your question.
4. Critically appraise the located evidence – describe and appraise the included studies. (Often the appraisal is limited to the methodological appropriateness of each study).
5. Summarize your findings – what’s the “bottom line” suggested by the evidence?

The CAT you write should include the following information:

1. Title

2. Clinical Bottom Line (what clinical action should be taken)

3. Original question

4. Search terms used

5. Summary of study methods

6. Table summarizing study results

7. Comments – (any important issues: side effects, contraindications, or subpopulations with different outcomes)

8. Expiration Date (no longer than 12 months from creation date)

9. Oxford Level of Evidence ( Grade Ia, IIb, etc.) http://www.cebm.net/index.aspx?o=1025

10. References

You may need to be familiar with research terms in able to complete the evidence table. 

You will need to know research terms like

• sample,
• independent variable, and
• dependent variable.

You will also need to know study designs, such as

• systematic review,
• randomized controlled trial,
• cohort study,
• qualitative study, and
• descriptive studies.

Use the glossaries below to (re)familiarize yourself with these terms and concepts.

Tip: The independent variable is the intervention. The dependent variable is the outcome.