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CDIS 413: Communication Sciences & Disorders Capstone: Evidence-Based Practice

Evidence-Based Practice (EBP)

Evidence-based practice is rooted in three elements.

  • Client/patient/caregiver perspectives
  • External scientific evidence
  • Clinial expertise/expert opinion

Step 1: Framing the Clinical Question

"The most difficult aspect of framing appropriate clinical questions is determining the level of specificity of what goes into each of these categories. To some, it is difficult because it is an art, rather than a science, and usually requires a fair amount of trial and error before the question is in its final form." -- ASHA: Framing the Clinical Question


Clinical questions require specific components. A common template used to formulate clinical questions is PICO (Population, Intervention, Comparison, and Outcome). Alternative templates might consider the environments and stakeholders. (Learn more about PESICO.)

PICO Template Description Example*
P Population, patient, problem. What characterizes this particular population? "English and Mandarin bilingual Singaporean speakers"
I Intervention. Describe the action or exposure that causes an anticipated change. "speech re-structuring intensive program (IP) delivered in English only"
C Comparison. What alternative is this being compared against? outcomes compared against "monolingual English-speaking adults"
O Outcome. What is the result? "stuttering reductions can be achieved in two languages following treatment in one language only"

*This example was taken from Lim, V. P. C., Lincoln, M., Onslow, M., & Chan, Y. H. (2015). English-only treatment of bilingual speakers who stutter: Generalization of treatment effects from english to mandarin. International Journal of Speech-Language Pathology, 17(5), 431-440.

Using PICO to frame a sample, clinical question, we might ask, "When speech restructuring IP is delivered only in English to bilingual English and Mandarin speakers, is stuttering reduced in one or both languages?"

Step 2: Finding the Evidence

Once you've initially framed your question, you'll need to search the available evidence. Your results can suggest the need to broaden or narrow your research question. If evidence is scarce, you may need to expand your population; if evidence is abundant, you may need to narrow the scope of interventions used. 

Use the tabs in this guide to find and search recommended resources. You'll find a large collection of information sources, but be especially mindful of systematic reviews. The proliferation of information makes it extremely difficult for healthcare professionals to stay current on research. Systematic reviews (SR) address this need, and are comprehensive studies of existing scientific literature on a particular topic. SRs have been systematically evaluated and essentially summarize a topic.

Step 3: Assessing the Evidence

In addition to evaluating sources according to CRAAP Test criteria, consider the following which are used by communicative disorder professionals when evaluating evidence

Independent confirmation and converging evidence. How much support is evident from other studies? How might areas of disagreement in other studies detract from overall supporting evidence? How rigorously researched were these supporting documents?

Experimental control. How were research elements managed and controlled by the research design? Was a (control) group used for comparison? Were participants randomly assigned between the control and treatment groups?

Avoidance of subjectivity and bias. How were subjectivity and bias removed or reduced by the research design? Were participants, researchers, and other involved parties removed from practices that might influence data collection or measurements? Were parties blinded or masked from activities that may be influenced by bias?

Effect sizes and confidence intervals. Was statistical analysis used to measure differences when comparing one thing to another? Were confidence intervals calculated and provided as part of the study?

Relevance and feasibility. In terms of relevance and feasibility, how pertinent is this study to its own stated aims and the overall purposes of communicative studies?

Step 4: Making the Clinical Decision

When making a clinical decision, it is important to come back to the three elements of evidence-based practice. This is true even, and perhaps especially, when guidelines already exist to help guide your decision. Consider the following when deciding the degree to which you will adhere to, or diverge from, existing guidelines.

  • Return to your original research question, and identify the points of congruence and incongruence. For example, how well is the population you're researching represented in the existing literature?
  • Critically examine the information before you to determine the degree to which they are evidence-based. For additional information, ASHA suggests reviewing the Appraisal of Guidelines for Research and Evaluation (AGREE).
  • Take a careful look at the parties who wrote, published, and backed the information before you to see what they might gain or lose by it.