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Running head: ARTICLE CRITIQUE 1

Quantitative Intervention Article Critique

Allyssa Farris

The University of Akron

ARTICLE CRITIQUE 2

Quantitative Intervention Article Critique

Logemann, J. A., Rademaker, A., Pauloski, B. R., Kelly, A., Stangl-McBreen, C., Antinoja, J.,

Grande, B., Farquharson, J., Kern, M., Easterling, C., & Shaker, R. (2009). A randomized

study comparing the shaker exercise with traditional therapy: A preliminary

study. Dysphagia, 24, 403-411. doi: 10.1007/s00455-009-9217-0

Introduction

Problem Statement

Since the field of speech-language pathology began to shift focus more on the evaluation

and intervention of swallowing disorders, several studies have been completed examining the

effectiveness of the Shaker exercise. In previous studies, this intervention method has been

utilized on specific, convenience populations usually obtained from a single institution. This

study explored the next step in providing evidence to the efficacious nature of the Shaker

exercise by comparing this intervention to traditional swallowing therapy and completing a

randomized clinical trial involving participants from numerous institutions.

Significance.

Dysphagia is a fairly new disorder remediated in speech-language pathology.

Articulation and language disorders, for years, have been the bread and butter, so to speak, of

this field. As the scope of practice has extended to include the diagnoses and intervention of

swallowing disorders it has become essential for studies to evaluate the effectiveness of

intervention strategies. Evidence-based practice that combines clinical judgment, client

preferences, and research is imperative to making sound clinical decisions to support the

individual needs of each client. Further research in swallowing disorders is crucial in providing

clinicians with empirically supported, best practices to implement into their therapy sessions

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with clients who have swallowing disorders. Moreover, swallowing intervention tends to be one

less academically emphasized in undergraduate and graduate programs, only increasing the need

for empirically supported interventions to guide clinical decisions. Additionally, using a

randomized sample from multiple institutions improves the ability to generalize results found

within a study. This study compares two well-known swallowing interventions in an attempt to

illuminate the most efficacious intervention in a way that has the most ability to generalize to the

general population.

Literature Review

This study highlights a need to assess the Shaker exercise in a randomized clinical trial.

It is therefore important to understand what the Shaker exercise is and what it attempts to

alleviate. At the beginning of this article, the researchers discussed factors affecting the opening

of the upper esophageal sphincter (UES). In various studies, the hyoid was found to lift the

larynx and pull the UES open when it moves anteriorly and superiorly during a swallow. The

researchers report the Shaker exercise is based on that specific anterior, superior motion of the

hyoid that results in the contraction of numerous extrinsic laryngeal muscles. The Shaker

exercise is comprised of isometric and isotonic exercises used to strengthen these extrinsic

muscles in order to increase the size of the UES opening.

Additionally, the researchers vaguely discuss previous research related to the Shaker

exercise. The researchers reported that over the years there have been a number of studies

appraising the validity of the Shaker exercise. However, in this literature review, the researchers

only outlined two studies. One study evaluated this intervention on an elderly population;

another study assessed this intervention on a tube-fed population. In all cases expressed in this

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article, the studies resulted in a wider UES opening. The researchers provided a list of references

consisting of twenty published articles.

Client Description and Justification

Currently, there are many more than just one client on caseload at my externship

placement that could benefit from an empirically supported swallowing exercise. This semester I

am placed at a rehabilitation and long term care facility whose primary clients are those with

psychiatric disorders. Due to the nature of their illnesses, most of the clients living at this facility

are prescribed heavy antipsychotic medications to diminish many of the symptoms of

schizophrenia, bipolar disorder, and personality disorders. Unfortunately, many of the

medications prescribed negatively affect the swallowing mechanism. Because a number of these

clients are weaned on and off of medications throughout the year, many of them come and go on

the caseload. At this time, I have six swallowing clients that are seen three-five times a week

who have oropharyngeal dysphagia due to medication interference or stroke.

I strategically chose an article that sought participants who experienced oropharyngeal

dysphagia. Luckily, the participants also experienced prolonged aspiration, which is one of the

criteria used to refer clients to the rehab team at my facility. This article was chosen to validate

or deny the efficacy of the Shaker exercise on oropharyngeal dysphagia, and to therefore help

guide my choice of intervention strategies.

Research Question

According to Logemann et al. (2009), “Our trial compared the Shaker exercise with

traditional swallowing therapy to determine if either treatment is better at reducing aspiration and

improving swallow function in patients with documented aspiration” (p. 404). This statement

does not explicitly define a hypothesis or research question; however, it does enable one to be

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inferred. From the quoted statement, the inferred research question is: Does the Shaker exercise

result in a greater reduction of aspiration and increase in swallowing function than traditional

swallowing therapy?

Methods

Participants

Demographic characteristics were expressed in a table that reported gender, race,

education level, diagnosis, and presence or absence of a feeding tube. All participants, even the

five who did not complete the study, were depicted in the table. The researchers reported, in the

results, that no significant differences were found between the two groups in respect to these

demographic characteristics. However, I saw some differences in the groups that pointed to

discrepancies in group equivalence. For example, the age ranges for the two groups were

significantly different. The group who received the Shaker intervention ranged in ages from 26-

84, while the group who received the traditional therapy ranged from 56-81. Practically

speaking those age ranges are substantially different with one group having individuals thirty

years younger than the youngest in the comparison group. Additionally the traditional group had

three more participants than the Shaker group.

According to the researchers, this study invited individuals from seven different

institutions to participate. These institutions included: Evanston Northwestern Healthcare,

Froedtert Hospital, H. Lee Moffitt Cancer Center, Northwestern University, St. Joseph’s Hospital

of Atlanta, St. Joseph Regional Medical Center, and Walter Reed Army Medical Center. The

researchers reported that all participants were randomly assigned to either the Shaker group or

the traditional therapy group. To randomly assigned and manage data collected, the research

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group utilized The American Speech Language and Hearing Association’s Communication

Sciences and Disorders Research Group. This group is located in Rockville, Maryland.

Participants were invited to join this study only after meeting a specific set of five criteria

points. The first inclusion criterion dictated the type of dysphagia, time since onset, and

causation of dysphagia. Patients were required to have oropharyngeal dysphagia of at least three

months post onset due to stroke or neck and head cancer. Some combination of post and pre

swallowing aspiration and inadequate UES opening was the second criterion used to qualify

participants. The third was residue present during videofluorography in the pyriform sinuses or

in the valleculae. Each participant needed a documented aspiration period of at least three

months. The fifth, and last, criterion was compliance to exercises and session attendance. The

19 individuals, from seven institutions, who were invited to participate in the study meet the

criteria listed above and did not meet any of the exclusion criteria which included: surgery to

extrinsic laryngeal muscles, cognitive deficits, alcoholic neuropathy, inability to carryout

exercises due to muscle atrophy, paresis, or paralysis, consumption of specific anticholinergics,

absent pharyngeal swallow, aspiration while swallowing, and neuromuscular disorders.

Participant Sampling and Limitations.

Given the previous studies completed, the researchers saw a need to evaluate the Shaker

exercise on participants from numerous institutions. The research team however did not

explicitly define the method they used for determining eligibility of institution. It is implied that

the institution where chosen at random. Vaguely describing the research sampling method leads

to discrepancies in the replication of this study and decreases the ability to generalize the results

of this study to other environments and populations.

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In order to participant in this study, patients were required to meet a list of inclusion

criteria. On this list was oropharyngeal dysphagia due to head and neck cancer or stroke.

Participants were stratified first by etiology and then randomly assigned to one of two

conditions. Each group was therefore equivalent, each having individuals from both strata.

Restricting the sample to only head and neck cancer or stroke patients dampens the ability to

generalize results to the greater population of individuals with oropharyngeal dysphagia.

However, this restriction does aid in decreasing the number of internal threats to validity.

Setting and Limitations

The research team provided little information in regards to the setting where the

interventions took place. From the description of the interventions, it can be assumed that the

interventions took place in each institution where the patients took residency. It is unclear;

however, where in each institution (therapy room, hallway, common areas, personal room, etc.)

the intervention was conducted. When the research study’s settings are not explicitly described,

it is difficult to create replication studies used to assess the validity and reliability of the study’s

results. Additionally, it becomes difficult for clinicians to determine which settings the

intervention’s results would generalize to.

Research Design

This true experimental research study utilized a pretest-posttest control group design.

The presence of a comparison group, acting as a control group, where both conditions are

manipulated by researchers and the utilization of random selection to ensure group equivalency

makes this research study a true experimental design. The participants were stratified based on

etiology of oropharyngeal dysphagia and then randomly assigned into two therapy groups. The

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study was comprised of two therapy groups; the Shaker exercise group and the traditional

therapy comparison group.

Research Design Limitations.

While the pretest administered at the commencement of this study helped ensure group

equivalency and provided baseline data to compare results to at the end of the study, the nature

of the pretest-posttest control group design leads to some limitations. In general, experimental

designs with a pretest can have issues with the pretest affecting the measurement of the

dependent variable at the posttest. For this study; however, each participant underwent a

modified barium swallow study at the beginning at end of the study. This is not the type of

evaluation that can be easily influenced by the participants; a person cannot easily influence the

trigger of their swallow to show a regression or progression of results. Moreover, the researchers

only gave one pretest at the end of the intervention period. Administering a posttest directly at

the end of the study shows immediate progress made due to the implementation of the

independent variable; however, it does not illuminate long term results. Generalizations about

the duration of time the independent variable continues to affect the dependent variable after the

independent variable has been withdrawn cannot be made without more posttests. To increase

the ability to generalize the results of this study, more posttests should’ve been conducted after

the withdrawal of the independent variable.

Implementation of Research Design

Group Descriptions and Limitations.

This experimental design used two conditions: a Shaker exercise group and a traditional

therapy group. Within the description section of these two therapies, each condition was

described. The Shaker group did three 1-minute head lefts followed by thirty consecutive

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repetitions of head raises. While the description of the actual exercise is thorough, the

description did not explicitly report how many total repetitions were done and how frequently

this exercise was repeated throughout the day. The traditional therapy group did a regiment of

exercises including the super-supraglottic swallow, the Mendelsohn Maneuver, tongue base

exercises, extended yawning, and a number of tongue retraction exercises. While this

description included the number of minutes each person completed the exercises, it did not report

how many repetitions of each exercise was completed or how the five minutes were broken

down among all the exercises done in the traditional therapy group. The researchers did well in

explaining the exercises used in each therapy group; however, they did not fully report the

precise amount of time spent on each exercise each day. Additionally, the researchers disclosed

how many days a week the interventions were implemented; however, they did not say what time

of day or where the interventions occurred. Without that absolute depiction replication studies

cannot be conducted. Replication studies increase the ability to generalize the study’s results,

which provides strength to the validity of the intervention.

Data Collection.

The data collection methods used at pretest were clearly reported. Before the

introduction of the independent variable, each participant underwent a modified barium swallow

study. During this evaluation, each patient swallowed liquid barium in the amount of 3ml and

5ml. This was done twice. Additionally, each patient swallowed a single 5ml bolus of barium

pudding. The results of each participant’s videofluoroscopic study were recorded and sent out,

to a laboratory taking no other part in the study, for analyzing. The videos were masked and

reviewed by two blinded analysts. Additionally, the videos were converted to digital copies so a

computer could analyze each video for anterior and superior hyoid movement, anterior and

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superior laryngeal movement, and the width of the UES viewed both anteriorly and laterally. The

presence of aspiration and the occurrence of residue within the swallowing mechanism were

monitored. At posttest, the pretest data collection methods were replicated. The researchers

evaluated each participant in the same way, using the same tools post intervention as they did

pre-intervention. Again, the researchers thoroughly described this process and the tools used to

collect data on the dependent variable.

Limitations

Although the majority of the data collection section of the article was well described,

there were a couple discrepancies with who was doing the observing and data collection. For

example, the researchers did not clearly report who performed the barium swallow studies, and

their level of competency and training. Different clinicians conducting the study might have

more training and experience giving the study and therefore inadvertently affect the dependent

variable measurements. Likewise, it is unclear how many individuals observed the videos and

how their results were compared. In one section two blinded analysts were described and in a

different section it was briefly reported the observations of the analysts were compared with the

results of the clinicians. These small discrepancies would make it slightly more difficult to

replicate this study without contacting the research team to gather further, concrete descriptions

of the data collection.

Dependent variables

The dependent variables in this study were the reduction of aspiration and the general

improvement of swallowing in participants who have a documented history of aspiration. In the

most basic terms, diminishing aspiration was the dependent variable. Many measurements were

taken to show the decrease in aspiration and the increase in swallowing functions. These

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measurements include: presence or absence of aspiration and pharyngeal residue, the anterior

and superior movement of the hyoid, the anterior and superior movements of the larynx, and the

width of the UES opening.

Measurement of Dependent Variables.

The changes in the dependent variables were measured several different ways. A

modified barium swallow study was conducted pre and posttreatment. This instrument was used

to measure the occurrence of aspiration during any phase of the swallow and the presence of

residue in the swallowing mechanism. Data was collected through observations of the videos.

Two blinded analysts reviewed the tapes, as well as, the participating clinicians; however, it is

uncertain at what points in time or in what manner their observations were recorded and

compared. This data was displayed in a table using nominal level data. This measurement noted

if there was or was not a presence of aspiration before, during, or after the swallow. The videos

where then digitized where in which a computer program analyzed the elevation and movement

of the larynx, hyoid, and the opening functions of the UES. Specifically, the programs that were

listed but not described were used to measure the width of the UES opening anteriorly and

laterally, anterior and superior hyoid movements, and anterior and superior larynx movements.

The computerized analyzing program measured those components in centimeters. These ratio

level data were then displayed along with descriptive statistics in a table. Lastly, The

Performance Status Scale for Diet was used and discussed; however, the researchers do not

specifically define this scale, describe how it was used, or what data is measured.

Instrumentation and Limitations

This study utilized different instruments and observations to obtain data on the dependent

variable. The first was the equipment used for the barium swallow studies (videofluroscopic

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evaluations). No information was given on their calibration. The article notes that each

participant’s videos were saved on a protected computer. These videos were digitized and every

third image for each patient was evaluated using a computer analysis program. The researchers

do not explain the program’s name, how it works, or who tranfered the data. It is unclear that

person(s) level of involvement or knowledge of the study. The article does report that the

measurements, although it’s unclear exactly which measurements are being discussed, were

calibrated using the penny’s diameter of 1.78 cm. Previous knowledge of this calibration

instrument or measurement is assumed. Furthermore, this study reported the two individuals

evaluating the videotapes were blinded; however, the study did not explain their training or

experience level. It is assumed the analysts are competently in evaluating larynx and hyoid

movement and the UES opening. Moreover, another assumption made is that the radiologists

running the equipment during the videofluoroscopic evaluations were unbiased and consistent

across participants. While the images used for data collection were described in detail, the

researchers did not report how many radiologists were used and what information they were

given about the study and the study’s hypothesis. Due to the lack of information revealed

regarding the instrumentation used during this study, the instruments are assumed to have

collected valid and reliable measurements of the dependent variable but without more

information this cannot be substantiated.

Validity and Reliability

In an attempt to obtain reliable data, the researchers utilized two blinded analysts. These

analysts reviewed and assessed the videos of the videofluoroscopic studies. Using blinded

analysts helped maintain integrity throughout the study. Additionally, the videos they were

observing were masked. The analysts did not know which results belong to what participants or

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what intervention group. Therefore, interobserver reliability was used as a consistency measure

to help ensure reliability of the dependent variable measurements. Moreover, in the results

section of this article the observations of the participating clinicians are discussed. The

researchers reported their observations were confirmed by the research analysts, adding another

layer of reliability

Internal Threats to Validity

When evaluating this research study, there are a few potential threats to internal validity

that should be addressed. The first, attrition, is highly applicable. This study had a very limited

number of participants to begin with, far less than originally planned, and five patients were not

included in the posttreatment data tables. According to the article, two participants in the

traditional therapy group did have the final barium swallow study done at completion of the

intervention phase, while three participants in the Shaker exercise group did not have the study

completed. Consequently, this was a dropout rate of 26%. Some confidence in group

equivalency is lost with that high of a percentage of attrition. Statistical analysis were done and

briefly and ambiguously described in an attempt to combat this threat.

Additionally, history could have also been an internal threat to validity present in this

study. It is assumes, although no specifically noted, that the individuals participating in this

study traveled to and from the clinics involved in the study. Therefore, events occurring in their

homes between the pretest and posttest measures of the dependent variable could have affected

the data collected. The researchers collected data on the amount of time the participants

practiced strategies outside of the clinics. The Shaker group practiced a median of 792 minutes

while the traditional group practiced a median of 1079 minutes. Even such slight differences can

affect how the participants respond to the independent variable.

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Instrumentation is another internal threat to validity that might have been present. Many

different methods of data collection were used during this study. Radiologist, either with or

without the presence of participating speech pathologists, completed the barium swallow studies.

It was not reported if the machinery used was recently and appropriately calibrated before each

series of testing occurred. They attempted to combat this threat by ensuring each participant’s

video expressed a certain number of images showing anatomical structures during the swallow.

Additionally, a computer program was used to measure the distance of movement of the UES

opening, the larynx, and the hyoid. While the article discussed the measurements of every third

picture being calibrated, no context is given. It is not clear what that calibration is referring to

and what impact that makes on this internal threat to validity.

External Threats to Validity

It is difficult to evaluate internal threats to validity without discussing external threats to

validity; there are a few potential threats to internal validity present in this study. Novelty is one

possible threat to external validity. This study was conducted in a fairly short time frame which

helped to combat history and maturation; however, it can contribute to the novelty effect

meaning the dependent variable measurements were a result of a new intervention. Additionally,

more potential external threats to validity include: experimenter, interaction of history and

treatment, and the interaction of time and measurement of the dependent variable. At each

institution that participated in the study, a speech pathologist implemented the two interventions.

The subtle differences in each clinician might have affected how the participants responded to

the independent variable. This study attempted to combat this threat by explicitly training the

therapists in each intervention. As previously discussed, events occurring outside the clinic may

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impact how each participant responds to the independent variable. The short duration of the

study naturally attempted to combat this threat; however, the implementation of more posttests

would have addressed this threat as well as the interaction of time and the dependent variable

measurement. Measurements of the dependent variable were taken only directly following the

end of the interventions. This greatly limits the ability to determine the long term effects of the

independent variables. More posttests could have more confidently shown the effects of the

independent variable over time.

Results

The majority of the results are clearly displayed in tables. The nominal level data used to denote

the presence or absence of aspiration is represented in the article’s second table. In the table, the

number of participants who demonstrated aspiration before, during, or after the swallow for each

intervention group was shown. The same format was used to show oral and pharyngeal residue

in all participants for both intervention groups. The physical representation of the data collected

was clear and apparent. The ambiguous results relate to the Performance Status Diet Scale that

was used to measure residue in the oral cavity and pharyngeal cavity. The researchers did not

explicitly describe this scale, the exact data obtained from this measurement, or the implications

of the data found from this measurement.

Descriptive Statistics

Descriptive statistics were used to report six measurements within the larynx. These

behaviors were used to evaluate how each condition impacted the participants’ abilities to

swallow. The graph displayed each of the six behaviors, the size of the movement measured in

centimeters for both pre and posttests, the standard deviation, as well as, the mean of the

movement distance. The mean and standard deviation are the descriptive statistics reported as

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measurements of the dependent variable. These statistics are appropriate given the ratio data

level used to describe these behaviors.

Effect Size and Limitations

This study did not explicitly report any effect sizes. Given the data provided in the

tables, a clinician could independently determine the effect sizes; however, the researchers did

not clearly provide them. Effect size describes the magnitude of the change seen on the

dependent variable as a result of the intervention introduced. This magnitude provides insight to

the practical significance associated with the implementation of the independent variable. The

researchers did not clearly state the effect size, and therefore does not provide a clearly defined

practical significance. The absence of this information begs to question whether the researchers

did not explicitly state it due to an unfavorable or small overall effect size.

Statistical Significance

This study utilized many different measurements of statistical analysis. The Fisher’s

exact test was used to compare patient characteristics of both groups, the Wilcoxon Rank Sum

Test was used to compare minutes practiced and change in diet, and the McNemar’s test was

used to compare dichotomous results between groups. The researchers did not explain the tests

used, the results from the measurements, or why those measurements were chosen. Additionally,

the article reported that the ANOVA was used to analyze the barium swallow studies, and t tests

were used to analyze pre and post treatment measurements within groups and between groups. A

prevalent limitation of the reporting of the statistical significance is the vaguely described tests

used to analyze the data. The researchers relied heavily on assumptions during the description of

this section.

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In terms of aspiration and residue, little to no statistical significance was found within

groups and between groups. As the graph below demonstrates, the only significant difference

between groups was the aspiration at post-swallow with a p-value of .028; however, the p-value

for the traditional group could not be tested thus calling into question the validity of this

difference measurement. Additionally, for swallowing the idea significance value would be less

than .02. Total oral and pharyngeal residue measured pre and post treatment displayed no

statistical significance between groups or within groups.

While referring to the hyoid, UES opening, and larynx measurements, a few increases

were noted in the traditional therapy group. The superior laryngeal movement with a p-value of

.009, the superior hyoid movement with a p-value of .044, and the anterior laryngeal movement

with a p-value of 0.026 demonstrate a significant difference if using the general communication

disorders standard of .05 to show significance. However, if using the dysphagia standard of .02,

only one value truly shows significance. Both therapies showed statistical significance of the

UES opening width; the Shaker’s p-value being .015 and the traditional therapy’s p-value being

.023. Aside from post-swallow aspiration, no statistical significance was determined between

groups for any of the dependent variable measurements.

Behavior Measured Shaker Exercises (p values) Traditional Therapy (p values) P Value

Between

Groups

Aspiration-

Preswallow

.32; not significant .32; not significant 0.99; not

significant

Aspiration-

Intraswallow

.32; not significant .32; not significant 0.99; not

significant

Aspiration-

Postswallow

0.08; not significant No Test 0.028; significant

Aspiration-Any 0.08; not significant No Test 0.028; significant

Width of UES

Opening-Lateral

3ml liquid: 0.09; not significant


3ml paste: 0.015; significant



3ml paste: 0.023; significant

.60

.67

.22

Anterior Hyoid

Movement

3ml liquid: .91; not significant

5ml liquid: .45 not significant

3ml paste: .34 not significant



3ml paste: .20; not significant

.12

.67

.056

Superior Hyoid 3ml liquid: .81; not significant 3ml liquid: .99; not significant .88

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Movement 5ml liquid: .25; not significant




.98

.55

Anterior Larynx

Movement


5ml liquid: no test


3ml liquid: 0.026; significant

5ml liquid: no test


.40

No test

.12

Superior Larynx

Movement


5ml liquid: no test



5ml liquid: no test

3ml paste: .009; significant

.65

No test

.84

Width of UES

Opening-Anterior


5ml liquid: no test

3ml paste: no test


5ml liquid: no test

3 ml paste: no test

.75

No test

No test

Confidence of Findings

While evaluating this article, a few limitations of this study were found. Firstly, the

frequency of exercises completed within each condition was not clearly described, creating a

problem with replication and therefore the ability to generalize the results found. Secondly, the

statistical analysis section of this article relied heavily on substantial knowledge of statistical

measurements. This entire section of the article was ambiguous and unclear. Additionally,

attrition of participants was significant, which impacted the confident level of the results found.

The limitations found weigh on my confidence level of this study’s findings.

In general, even given the limitations, I am fairly confident the results found truly

demonstrated the effects of the independent variables on the dependent variable due to the

study’s attempts to control extraneous variables and combat internal and external threats to

validity. Moreover, I am fairly confident this study fulfilled the requirements of a true

experimental research design and attempted to compare two swallowing therapies using valid

and reliable implementation and instrumentation. The questions remaining about the data

collection process could be easily found by contacting any member of the research team. This

study utilized many avoidance techniques to combat internal and external threats to validity. To

protect the validity and integrity of the study, a stratifying sample procedure was used in

conjunction with random assignment to ensure initial group equivalency, the clinicians were

trained and presumably highly competent in each intervention to ensure each participant received

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the same intervention, the two analysts were blinded and reviewed masked video recordings to

decrease the possible influence of biased observers, and the two conditions were explicitly

described which increased the likelihood of replication.

Conclusion

Guiding Practice

Practicing speech language pathologists could use this article to guide their practices in a

number of ways. Three out of five participants who finished the study in the Shaker group had

no post-swallow aspiration at post intervention testing when post-swallow aspiration was present

at pretesting. The number of participants was greatly smaller than researchers anticipated and

the p-value of these measurements were not shown to have statistical significance. However,

given that three out of five individuals no longer aspirated after swallowing in the post

intervention assessment, I would say the practical significance is evident. In contrast, no

improvements to post swallow aspiration were shown in the traditional therapy group.

Therefore, this article could guide clinicians towards further research of the Shaker exercise for

the remediation of post-swallow aspiration.

Likewise, the traditional therapy techniques demonstrated increases from pretesting to

post testing in regards to superior and anterior laryngeal movement and superior hyoid

movement. While the p-value for all three of these measurements do not specifically display

statistical significance for dysphagia (less than .02), they do make a compelling argument for the

effectiveness of traditional therapy as opposed to the Shaker exercise which showed no statistical

significance on these three measurements. Given a client with minimal elevation and forward

movement of the larynx, this article could point a clinician in the direction of finding and

evaluating more research on traditional therapy and its effectiveness.

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Evidence-Based Practice

According to author Timothy Meline (2010), evidence-based practice is a process

intended to provide clients with the best quality interventions through examining and comparing

three main components. These components include current, relevant scientific evidence, clinical

experience, and client preferences. It is essential to the process that each of these components is

taken into account before making clinical decisions or recommendations (Meline, 2010).

To examine the scientific evidence, a component of evidence-based practice, the table in

the Gillam and Gillam (2006) article that discusses critical appraisal questions related to

randomized clinical trials (level 1 evidence) can be used. The first two questions inquire about

random assignment and the presence of a control group. In this study, the participants were

randomly assigned to one of two conditions, a Shaker exercise treatment group and a traditional

therapy comparison group. The third question relates to the participants and the information

disclosed about all participants within the study. This study displayed the demographics of the

participants in a graph. All the participants demonstrated a history, of at least three months, of

aspiration. Many of the clients on caseload are on diet modifications due to overt or silent

aspiration. The sample used in this study were stratified based on the etiology of their aspiration;

once stratified, the participants were randomly assigned to ensure initial group equivalency. A

minor concern related to initial group equivalency was a discrepancy in the number of

participants in each group. At the study’s start, 11 patients were in the traditional group and 8 in

the Shaker group. After the loss of five participants, 9 ended in the traditional group and 5 in the

Shaker group. The next two questions relate to blinding procedures and reliable measurements

of the dependent variable. The analysts who reported the results were blinded and the videotapes

themselves were masked. Additionally, the observations of the clinicians implementing the

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independent variables were compared with the observations of the two blinded analysts,

providing interobserver reliability. The researchers providing explicit training to at least the

clinicians implementing the interventions and the pretest measurement procedure was identically

replicated for posttest data collection. The problem lies with the lack of statistical significance

shown and the absence of practical significance. The majority of p-values reported,

demonstrating a difference in pre and post test results, were not less than .02; most of the results

were not even less than .05, the general standard for communication disorders. The only p-

values that fit these criteria were for the width of the UES opening in both groups, and the

superior and anterior larynx movements and superior hyoid movement in the traditional therapy

group. The researchers did not provide practical significance through the reporting of the effect

size. Most of the answers to the critical appraisal questions regarding this study were yes.

According to Gillam and Gillam (2006), the more yes answers provided in this appraisal process,

the more assured clinicians can be that a study is reliable and high quality. That being said, the

lack of practical significance reported and the minimal statistical significance found doesn’t yield

great confidence in either of the two interventions.

The other two components of evidence-based practice are clinical experience and client

preference. Since August, numerous residents have shown positive results in their swallowing

from both intervention strategies. The quickest results seen at this facility for oropharyngeal

dysphagia have been when using the two interventions, traditional therapy and the Shaker

exercise, concurrently. Unfortunately, patients at this facility have to be sent out to receive

barium swallow studies, which occurs infrequently, leaving the measurements of signs and

symptoms of dysphagia to be measured by bedside assessments, meal analysis, and checklists

usually reported by observations alone. As for client preference at this facility, I have found that

ARTICLE CRITIQUE 22

the only real preference is in relation to the diet modifications. The majority of clients at this

facility do not want their oral intake, especially coffee, altered in any way regardless of the

ramifications. The most frequent complaint received by the rehabilitation team is the aversion to

the exercises that are most straining such as the interdental swallow (Valsalva exercise).

After careful analysis and consideration, this study alone does not confidently

demonstrate support for the Shaker exercise being an evidence-based practice. While I am fairly

confident in the results found based on the research design and implementation, the results did

not prove the effectiveness in reducing aspiration of either intervention group. This is the first

randomized clinical trial comparing these two interventions. Given the amount of research on

the Shaker exercise and traditional maneuvers available to reference and the thoughtful design of

this study, supplementary randomized clinical trials could be completed to further investigate the

effectiveness of traditional therapy and the Shaker exercise on improving oropharyngeal

dysphagia. However, given the results seen in the rehabilitation facility, the goals of the clients

to return to a normal consistency diet, and the improvements (UES opening, hyoid movement,

larynx movement) found by this study (and the lack of regression/worsening), these two

swallowing interventions could be trialed in practice and monitored for efficacy.

Further Research Needed

Past research studies have shown the Shaker exercise to have resulted in an increased

UES opening. This clinical trial also demonstrated a statistical significance in the measurement

of the UES opening width from pretest to post-test; however, only five participants were given

post pre and post tests. Another randomized clinically trial should be completed, replicating this

study’s research design, with a greater number of participants to add another level of validity and

reliability to the results found. Additionally, further randomized clinical trials should be

ARTICLE CRITIQUE 23

completed to evaluate the Shaker exercise’s effectiveness at reducing aspiration. This study’s

results were not statistically significant; however, three out of the five showed no post swallow

aspiration at the time of post test. Narrowing the dependent variable to be measured and

explicitly defining the implementation of the independent variable should be focused on in any

replication studies of this nature. Lastly, replicating this study utilizing a different sample of

participants from the dysphagia population would help generalize results to individuals who have

oropharyngeal dysphagia due to other etiologies besides cancer and stroke. Including individuals

who have dysphagia due to neurological conditions, laryngeal trauma, or medication interference

would be helpful in the generalization of results.

ARTICLE CRITIQUE 24

References

Gillam, S. L., & Gillam, R. B. (2006). Making evidence-based decisions about child language

intervention in schools. Language, Speech, and Hearing Services in Schools, 37, 304-

315.

Meline, T. (2010). A research primer for communication sciences and disorders. (pp. 49-69).

Boston, MA: Pearson Education, Inc.

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