Where Do I Go From Here? Practice-Based Evidence Provides Direction



By Heather Jeng

Sept 21st is World Alzheimer’s Day. Treating a person with a degenerative disease process requires focusing more on intact strengths and environmental factors than deficits. This is referred to as habilitative (vs rehabilitative) intervention. A common treatment challenge is making sound evidence-based decisions when designing and modifying the treatment plan. But evidence does not come only from research studies. In honor of all of our patients with Alzheimer’s, this post explores how evidence is generated every day in treatment sessions, and how clinicians can harness it to provide effective treatment with confidence.

Practice-Based Evidence? Isn’t it Evidence-Based Practice?

Clinicians are acutely aware of needing to provide treatment based on best current scientific evidence. Research evidence, combined with client/caregiver perspectives and clinical expertise, is the evidence-based practice paradigm we learned about in graduate school. (For a refresher or new learning, check out the ASHA EBP Web-Based Tutorials! SpeechBITE also offers an online rating training program to improve your skill in rating studies’ quality of evidence.) EBP is a framework for providing the best possible services we can, and it is also our ethical duty. However, clinical practice soon teaches that EBP has its limitations.

Rik Lemoncello and Bryan Ness review these limitations in their excellent article “Evidence-Based Practice & Practice-Based Evidence Applied to Adult, Medical Speech-Language Pathology.” They include:

  • A limited amount of high-quality evidence
  • Limitations of randomized controlled trials (not every intervention can be explored via a RCT; your client may not present like the study participants; even if your client matches the study’s participants well, they may have some crucial individual preferences that create a barrier to implementing the treatment as described)

Why Do We Need PBE?

In the context of research, they outline how single-case experimental designs can address some of these limitations. In the clinical world, they turn to the concept of practice-based evidence (PBE). As they state, “PBE offers the evidence-based clinician options when EBP does not provide convincing or consistent empirical evidence to support or refute a practice.” Very important point: PBE does NOT replace EBP! But in cases where:

  • there isn’t high-quality evidence available, (meaning, the research evidence is simply not out there, not that it’s difficult to access. There are solutions for accessibility), or
  • evidence conflicts,
  • evidence doesn’t apply to a particular patient
  • doesn’t provide one clear path forward

then we need a complementary approach to guide clinical decision-making.

How Does PBE Work? Some Options

Lemoncello and Ness highlight three questions that clinicians always need answers to. They are:

  1. Is the client responding to the intervention? (requires treatment data)
  2. Is the change functional? (requires generalization data)
  3. Is the treatment responsible for the observed change? (requires control data)

To answer Questions 2 and 3, they recommend using single-case experimental design using multiple baselines and collecting control data. They take the treatment example of recalling and executing safe assistive device use: ambulating with a walker. We know in Alzheimer’s that procedural recall is enhanced and the skill is generalized when it’s trained in meaningful contexts. So, in their example, the clinician chooses three contexts for a multiple baseline design: the person’s room, the therapy gym, and the hallways. After collecting baseline data, and training the steps of safe walker use via errorless learning, the therapist implements the training in each context. Multiple baseline data shows that in fact, the client does not generalize to new contexts without training specifically in that setting. Practice-based evidence helps justify why training in specific contexts is needed for this particular patient, and helps the SLP inform PT and OT what type of instruction will be necessary for any additional contexts.

Control data help establish that the intervention, rather than any of the many other uncontrollable factors in the patient’s life, is responsible for the change in the targeted skill. For example, let’s consider a patient with Parkinson’s who is being seen to increase loudness. The clinician selects another skill that should not change with voice treatment, for example, verbal fluency. If the targeted skill (loudness) improves over time in treatment, while the non-targeted control skill (verbal fluency) remains roughly the same, the clinician has evidence that the intervention is responsible for the improvement. In a case where the control skill also improves, the clinician would have to consider other factors such as spontaneous recovery.

This brief summary does not do justice to the full article, which is a clinical gem! It’s a great one to read if the concepts of incorporating multiple baselines and control data into treatment are new to you. It’s also a great one to tuck into a graduate student intern binder or have on hand for Clinical Fellow supervision. The article was published in the Special Interest Group 15 Gerontology Perspectives journal. If you’re an ASHA member and don’t already belong to a SIG, consider joining one. They’re a great way to meet experts in your interest area, and get CEU credit for learning from clinically-relevant Perspectives journals.


Lemoncello, R., & Ness, B. (2013). Evidence-Based Practice & Practice-Based Evidence Applied to Adult, Medical Speech-Language Pathology. Perspectives on Gerontology, 18, 14-26. doi:10.1044/gero18.1.14

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