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DPT 702: Principles of Inquiry: Evidence-Based Physical Therapy

Course Textbook


Evidence-based practice uses the PICO model for formulating a searchable question.

P = Patient/Population or Problem
Describe the patient, population or problem succinctly. Include the type of patient or population and the setting. Consider attributes such as age, gender, and/or symptoms.

I = Intervention
The intervention can be a treatment; a clinical, education or administrative intervention; a process of care; nursing treatments; strategies for education; or assessment approaches.

C = Comparison
Determine if a comparison group exists. Will this intervention be compared to another? Not all questions have comparisons. A statement of current practice may be used as a comparison.

O = Outcome
Identify the outcomes of interest. Outcomes may include quality of life, improved treatment results, decreased rate of adverse events, improved patient safety, decreased cost, or improved patient satisfaction. The outcomes always include a metric for measuring results and the frequency for measuring and reporting results.

Effectiveness of Reviews Pyramid

There is a range in quality of evidence available in the literature, with meta-analysis and systematic reviews being the very highest quality. As you move up the pyramid, the amount of literature decreases but its clinical relevance increases.

Sources of research may be either pre-appraised (summaries), primary literature or more anecdotal.


Meta-analysis or Systematic Reviews PubMed, CINAHL, SPORTDiscus, PEDro
Critically-Appraised Topics ClinicalKey,
Critically-Appraised Articles  
Randomized Controlled Trials Original articles (search CINAHL, PubMed, SPORTDiscus)
Cohort Studies Original articles (search PubMed, SPORTDiscus)
Case-Controlled Studies etc. Original articles (search CINAHL, PubMed)
Background Info/Expert Opinion Books, editorials (search print & e-books, CINAHL, PubMed)

Hierarchy of evidence for clinical questions

Always start an EBPT search looking for the highest level of evidence. If a meta-analysis is not available on the topic, look next for systematic reviews without statistical synthesis, next for randomized control trials, next for controlled comparison or case control studies, etc.

  • Meta-analyses: Methods of synthesizing the data from more than one study, in order to produce a summary statistic

  • Systematic Review: [tries] to answer a clear question by finding and describing all published, and if possible, unpublished work, on a topic. [It] uses explicit methods to perform a thorough literature search and critical appraisal of individual studies and uses appropriate statistical techniques to combine these valid studies (Booth & Brice, 2004).

  • Randomized Controlled Trial (RCT): are also called 'randomized clinical trial.' They involve the random assignment of subjects to groups   that are then given different interventions to assess the effects of the interventions.

  • Controlled Comparison or Case Control Study: is an observational study in which the cases have the issue of interest

  • Descriptive Surveys: studies aimed at describing certain attributes of a population, specifying associations between variables, or searching out hypotheses to be tested, but which are not primarily intended for establishing cause-and-effect relationships or actually testing hypotheses.

  • Case Studies: describe a particular service or event, often focusing on unusual aspects of the reported situation or adverse occurrences, commonly have exploratory, descriptive, or explanatory purposes.

    Booth A & Brice A (2004) Evidence Based Practice for Information Professionals: A Handbook. London: Facet Publishing.

Subject Guide

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Titles of Interest