Title: Impact of Dysphagia Rehabilitation in Adults on Swallowing Physiology Measured With Videofluoroscopy: A Mapping Review
Authors: Namasivayam-MacDonald, Rapley, Stewart, Webster, Quon, & Rogus-Pulia
Journal: American Journal of Speech-Language Pathology
Year of Publication: 2022
Design Type: mapping review
Purpose: “This mapping review explored the existing literature on dysphagia rehabilitation approaches and its impact on swallowing physiology, as measured based on VFSS images. The primary aim of this study was to generate evidence maps to identify which swallowing rehabilitation approaches improve which aspects of swallowing physiology per the MBSImP components.”
Inclusion criteria: a) prospective/retrospective published research in English; b) >18 year-old adults; c) identified swallowing difficulties; d) physiological impairments viewed from VFSS; e) at least 1 outcome measure could be mapped to an MBSImP component describing swallowing physiology
Exclusion criteria: a) conference abstracts; b) only healthy participants; c) studies of compensatory approaches for im[aired swallowing; d) studies focused on proactive intervention; e) studies focused on nonactive exercise approaches; f) studies involving individualized intervention across participants; g) studies utilizing clinical or other instrumental assessments to measure physiological change (e.g. FEES) without a validated, comparable tool; h) studies only evaluating (oral/pharyngeal residue)
- Only got a sec?
- Specific physiological impairments taken from MBSImP can be mapped with evidence for certain rehabilitative interventions
- Only got a minute?
- “Given these studies, it is essential that clinicians are provided with a resource to facilitate better use of the available evidence. This is critical given that treatment selection not informed by the patient’s physiological impairments has potential implications for patient outcomes, as positive treatment outcomes are typically dependent upon clinicians understanding the swallowing pathophysiology and using that knowledge to choose the most appropriate treatment (Easterling, 2017)“
- “our review is unique in that it directly maps swallowing physiology using the MBSImP framework to rehabilitative intervention approaches, with consideration of the magnitude of change that we can expect“
- “This review highlighted that decisions pertaining to dysphagia rehabilitation are made primarily based on low levels of evidence (most often level 2B) that may prevent clinicians from being certain if a particular rehabilitation approach is more beneficial than the current standard of care“
- “even in the absence of statistical significance, it may be that certain swallowing interventions are positively impacting outcomes despite small sample sizes“
- Got more time? Keep Reading!!
There’s no doubt the vast majority of us wish we had a better map when it comes to the island of dysphagia (at some point we didn’t even have a map!). From so many different ways to describe, examine, test, compare, and treat the swallowing mechanism, it’s no wonder why we all feel so lost most of the time!😩
This forward-thinking team bravely tried to make connections between what we might see on fluoro, what we might need to do to fix it, and what we still need to figure out given the lack of evidence for some parts.
If you’re feeling brave to discover the results, let’s dive into this adventure!🤠
The authors hit us pretty hard right from the start by pointing out what we as clinicians all know and feel too well:
“Despite the importance of evidence-based decision making, there is a lack of consensus in the literature regarding which intervention approaches are most appropriate for targeting a specific swallowing impairment or set of impairments (Vose et al., 2018).” p.2
“The lack of consensus in the literature may also be leading to a lack of consensus among practicing clinicians. Two separate studies have identified a lack of consistency among clinicians when identifying swallowing impairments and selecting appropriate treatment approaches for specific physiologic impairments (Carnaby & Harenberg, 2013; Vose et al., 2018).” p.2
Yup. That’s quite a gut punch😵💫. When we get results that show:
- “96 different combinations of treatment teqchniues were recommended after viewing the same swallow study“
- “only 4% of responses were derived based on a specific physiologic abnormality”
- “58% of recommended techniques did not match the dysphagia-related symptoms specific to the hypothetical patient“
- “73% of respondents did not mention physiology in their rationale for treatment choice after reviewing a complex case” (Vose et al., 2018)
They even put our practices right in front of us by showing in a 2016 survey “clinicans report their choice of dysphagia interventions is primarily based on patient suitability and clinical experience” and put the spotlight on the fact that many treatment decisions are “based on bolus-related outcomes (i.e. aspiration, penetration, residue, and esophageal clearance) rather than specific physiologic impairments” (Vose et al., 2018).
So with this in mind, the authors seek to essentially answer:
“How do swallowing rehabilitation approaches impact specific swallowing impairments in adults with dysphagia?”
How are they gonna that?!
Well, by utilizing all their fancy PRISMA tools and after searching across databases with their search terms (see their appendix to get an idea what they were looking for), selecting relevant articles based on inclusion/exclusion criteria, reviewing texts, and extracting data in a double-blinded way, the authors came up with their own system of how to classify, divide, and describe the studies they found.
But, the main points for what type of data and info we’ll be seeing in the results…
“Data extracted included the swallowing rehabilitation approach employed, study characteristics, and the resulting change in swallowing physiology.” p.3
Because studies used different approaches, they were further grouped into either those that used single approaches or multi-approach.
If you thought every single study they found used MBSImP tool as an outcome measure—think again!!
“The resulting changes in swallowing physiology were mapped to at least one of the 17 MBSImP components, where applicable. Unfortunately, many studies included in this review did not utilize the MBSImP tool as an outcome measure; therefore, it was decided that mapping would be performed based on consideration of the name of each component, rather than the operational definition, to allow for broad applicability.” p.3
They also compared another frequently used outcome measure—Videofluoroscopic Dysphagia Scales (VDS), aka Functional Dysphagia Scale—to see which ones could be matched up to the MBSImP components. Never heard of it before, but I’ll add it to the list!
The authors make a pretty compelling argument against the “power of the p-value,” basically explaining that because the majority of studies in our field have small sample sizes, only looking at the p-value to determine a “statistical significance” really doesn’t mean as much as trying to look for actual meaningful significance.
Confused🥴? Yeah, me too at first. Basically:
- p-value = strictly statistical significance
- there may be a statistical significance, but a) this might not equate to actually clinically meaningful change, OR b) it might just be because it’s easier for the stats to look significant when the sample sizes are so small! (When you only got a handful of gems, the 1 or 2 gems may look more beautiful than when you have a whole store full😉)
- it’s kinda like when you don’t have a lot of x, you cherish whatever x you do have way more. When you have ample amounts of x, you might not be as grateful or it may not hold as much meaning to you (because you have so much in supply)
- Effect size = can be more helpful to decipher the extent of any difference found
- because sample sizes are smaller, given whatever data there is, we can try to see how much of an impact this would have realistically
- “To consider how small sample sizes may have skewed results, effect sizes were either extracted or calculated when the necessary data were available for single approach studies. Effect size was not included for multi-approach studies given that it is not clear if the combination of exercises or a single approach within the combination was critical in improving swallowing outcomes.”
I don’t know about you, but,
The last pieces to the puzzle before making their map was incorporating the Rehabilitation Treatment Specification System (RTSS). Again, never heard of it before but glad I kept learning so much throughout this article!🤯
“Using the RTSS, rehabilitation treatments are specified using three elements: targets, ingredients, and mechanisms of action…Considering relationships among elements of the RTSS can aid clinicians in choosing rehabilitation approaches that best fit with their goals for therapy with their patients (Turkstra et al., 2016).” p.4
- Targets = describe aspects of the patient’s functioning the clinician is attempting to directly change
- Organ function, skills & habit, and representations
- Organ of function–> “are concerned with changes in the efficiency, functioning, or replacement of an organ or organ system (e.g. exercise, habituation, prosthetics)”
- Skills & Habits–> “involved in modifying mental or behavioral skills through providing ingredients such as practice, repetition, feedback, etc.”
- Representations–> “intended to change mental representations related to cognition, affect, motivation, and volitional behavior”
- Organ function, skills & habit, and representations
- Ingredients = observable and measureable actions that are delivered in therapy by the clinican to produce changes in the target
- Mechanism of action = the known or hypothesized process by which the treatment’s ingredients generate change on the target
And finally, the authors also went ahead and assigned the level of evidence for each study (per American Society of Plastic Surgeons?🤨) AND graded each exercise approach (per CEBM levels of evidence for therapeutic studies).
So, with all that information, categories, components, and classifications, after consensus the authors eventually came up with a total of 43 “unique” articles and used 47 studies, of which 35 were reported as a single approach (with 117 outcomes measures able to be mapped to MBSImP) and 13 as a multi-approach (with 60 outcomes measures able to be mapped). Despite a range from 1994 up to 2021, 80% of the articles were from the past 10 years. If you feel like perusing their multiple lists of articles for the specific details (2 studies even showed statistical significant reduction in anterior hyoid excursion!😮), be my guest! Otherwise, here’s a quick breakdown of what their almost-tripled baker’s dozen of data looked like when combining it all together:
- A total of 975 participants
- Almost 50% of primary diagnoses were stroke (interestingly enough I didn’t see muc related to esophageal type of diagnoses??)
- Most frequently components mapped to MBSImP:
- Anterior hyoid excursion and laryngeal elevation (in single-approach studies)
- No studies had outcome measures to map esophageal clearance
- fewer for pharyngeal contraction, stripping wave, or tongue control
- 43% articles reported subjective observations as outcomes
- 13 different exercise approaches were investigated (across single-approach studies)
- Most supported approaches:
- Shaker/Head Lift Exercise
- Jaw Opening Exercise
- McNeill Dysphagia Therapy Program (MDTP)
It gets a bit dirtier when we start sorting all the details out….
Specifically, while anterior hyoid excursion and laryngeal elevation showed the most frequent improvement, you also have to consider that these were also the 2 most frequently measured in studies (so it makes sense they have more data to back it up!).
Unfortunately, not all studies included or provided enough information to determine effect sizes (MDTP, Respiratory Swallow Training, Tongue Resistance Training). But luckily out of the “19 large effect sizes, 13 (68%) also reported a statistically significant change and six (32%) did not.”
“even in the absence of statistical significance, it may be that certain swallowing interventions are positively impacting outcomes despite small sample sizes.” p.28
And if you were wondering about those new RTSS categories, apparently it was all but unsurprising (feel free to go back to reference the descriptions of each from above😉):
- Organ function targets were most frequent target category
- Most studies used devices to facilitate treatment (e.g. IOPI, CTAR device, NMES)
- Consistent dosage details were lacking across studies (only EMST studies reported on intensity)
- Common ingredients included instruction, calibration, practice, feedback, and training logs
- LSVT and MDTP lacked transparency for replication (makes sense given their disclosures🤫)
Luckily, the authors give us a guide for what to do with all this information as practicing clinicians. The first step is completing a VFSS and utilizing the MBSImP protocol with physiology (kind of have to since that’s what everything is based off😉). After that, it’s a matter of using their evidence maps to find a corresponding exercise approach with the impaired physiology.
“For example, if pharyngoesophageal segment (PES) opening is the identified impairment, the clinician would refer to the evidence maps and note that JOE [jaw opening exercises] were consistently found to support improvement in PES opening (see Figure 3) and has three studies that demonstrated large effects for improving hyoid excursion (see Figure 4).”
“The clinician can then refer to the results tables (see Tables 4 and 5) to identify the specific studies that reported this improvement. Next, the clinician can find the corresponding studies in the RTSS tables (see Tables 6 and 7) to learn what specific ingredients led to the improvement.” p.27
While the authors make clear that their review and map doesn’t relate to any specific diagnosis (this obviously can have a direct impact on physiological impairments and outcomes), they still offer important factors to consider when going through the treatment selection process:
- impaired physiology, ideally per an instrumental assessment
- the evidence supporting each approach
- the resources available, per facility
- the training available to implement the approach, per what was learned in graduate school and currently available continuing education courses; and
- the patient’s personal factors (e.g., diagnosis, goals, and values)
Another thing to consider: “the most common level of evidence was 2B, representing an individual cohort study,” and that the overall grades ranged from a “B” to a “D.” Yet despite some limitations with only having English studies, excluding other diagnostic tools like FEES and other physiological measures (e.g. timing or pixel measures, ASPEKT), and also not being able to really report on quality of life measures or even reliability on the VFSS/outcome measures across all the studies (“this is important to consider as inadequate reliability when deriving measures from VFS studies may impact the validity of results reported”), the authors push forward the idea that starting some sort of standardization for treatment planning is much needed to assist clinicians and avoid “emotional” or even uninformed decisions that ultimately impact our patients and their progress.
The authors honestly admit that while MBSImP is one option for standardization that their report uses, there are other options as well, and also recognize the level of clinician knowledge and training also inherently plays a big role.
So whether it be only 1 tool you use or many others you’re now open to exploring and maybe adopting, we should all be thinking a bit deeper into what we’re seeing, why we might be seeing it, and what evidence best matches to achieve the improvements we want because regardless of what it is, clinical practices shouldn’t be left to being updated only during Spring Cleaning🤓
Article Referenced: [ASHA FREE ACCESS]
Namasivayam-MacDonald, A., Rapley, M., Stewart, J., Webster, E., Quon, C., & Rogus-Pulia, N. (2022). Impact of Dysphagia Rehabilitation in Adults on Swallowing Physiology Measured With Videofluoroscopy: A Mapping Review. American Journal Of Speech-Language Pathology, 1-34. doi: 10.1044/2022_ajslp-21-00342