Oct 28, 2021
Dr. Janet Patterson, Research Speech-Language Pathologist at the VA Northern California Healthcare System, speaks with Rob Cavanaugh of the University of Pittsburgh, about dosage in delivering aphasia treatments, and about the difference between dosage in research settings and dosage in clinical settings.
In today’s episode you will hear about:
Janet Patterson: Welcome to this edition of Aphasia Access Podversations, a series of conversations about community aphasia programs that follow the LPAA model. My name is Janet Patterson, and I am a Research Speech-Language Pathologist at the VA Northern California Healthcare System in Martinez, California. Today I am delighted to be speaking with my friend and an excellent researcher, Rob Cavanaugh, from the University of Pittsburgh. Rob and I have had several conversations about aspects of aphasia rehabilitation, beginning when he was a Student Fellow in the Academy of Neurologic Communication Disorders and Sciences. Our conversation today centers on a topic we both have been thinking about, dosage and aphasia treatment.
As Rob and I start this podcast, I want to give you a quick reminder that this year we are sharing episodes that highlight at least one of the gap areas in aphasia care identified in the Aphasia Access White Paper, authored by Dr. Nina Simmons-Mackie. For more information on this White Paper, check out Podversations Episode 62 with Dr. Liz Hoover, as she describes these 10 gap areas, or go to the Aphasia Access website.
This episode with Rob Cavanaugh focuses on gap area 4 - Insufficient intensity of aphasia intervention across the continuum of care. Treatment intensity is not a singular concept, but rather has several components to it, including decisions about dosage. Much has been written about intensity in aphasia rehabilitation, however, as yet there is no clear and convincing argument about what, exactly, is the best intensity for delivering an aphasia treatment to an individual with aphasia. I hope our conversation today can begin to shed some light on this topic.
Rob Cavanaugh is a third year Ph.D. candidate in the Department of Communication Sciences and Disorders at the University of Pittsburgh. Before moving to Pittsburgh, he worked as a clinical speech-language pathologist in Charlotte, North Carolina, in outpatient and inpatient rehabilitation settings. His research interests focus on identifying implementation gaps in aphasia rehabilitation, improving patient access to therapy services through technology, improving treatment outcomes, and advancing statistical methods used in aphasia research. Rob received his master's degree in Speech and Hearing Sciences from the University of North Carolina at Chapel Hill. He is currently doing interesting work at Pitt, and I look forward to our conversations, Rob, today and in the future. Welcome, Rob to Aphasia Access Podversations.
Rob Cavanaugh: Thanks Janet, it's great to be here, and I'm really excited to talk about dosage and aphasia treatment.
Janet: Great! I think the only thing I'm going to have to worry about Rob, is keeping us contained because we could probably talk for days on this subject, and our listeners would get tired of hearing us.
Rob: That is definitely true.
Janet: Today, as I said, Rob, I'd like to talk to you about dosage and aphasia treatment. You and your colleagues recently published a paper in AJSLP that compared dosage in research papers and dosage in clinical practice. The team did great work, and I think it's an impressive paper. As we try to create an effective and efficient treatment program for our clients with aphasia, one of the elements we consider is dosage of the treatment we select. Simply defined, dosage can be thought of as the amount of treatment provided at one time, how often that treatment is provided, and the length of time the treatment lasts. We sometimes hear the terms session length, frequency and duration. Would you agree with that definition, Rob?
Rob: Thanks, Janet. I'm really excited about this work, and I want to take a minute to acknowledge the research team on this project before we really get into dosage because it really was a big team effort. Christina Kravetz is a clinical speech language pathologist here in Pittsburgh, Yina Quique, who is now a postdoctoral fellow at Northwestern, Lily Jarold who is now working on her clinical master's degree at the University of South Carolina, and Brandon Nguy who I think you had on an Aphasia Access Podversations a couple weeks ago to talk about his presentation and some of his work analyzing demographic trends in these data. I should also acknowledge our funding sources, which include the School of Health and Rehabilitation Sciences here at Pitt, and the National Center for Advancing Translational Sciences.
I think that's a good definition to get us started talking about dosage. We know that the amount of treatment is most often reported in terms of time, how many minutes in a treatment session, or how often sessions occur, or how many total sessions are there. But perhaps I can add one more dimension to our discussion about dosage, which is that it's not just how much treatment occurs in terms of time, but also what the treatment is made up of, what are the activities that we're doing within the treatment? How many times do we do them in a session? Or how many times do we do the activities per hour of treatment? As much as I'd like to think of dosage and aphasia treatment as an analogy to taking an antibiotic, such as when you have strep throat or some infection, you take 250 milligrams twice a week for two weeks. Dosage in aphasia rehabilitation is probably not that straightforward, right? Our treatments are complex and holistic and answering questions like how much of something gets really tricky really quickly.
Janet: I can imagine, and you know, when we first started talking about dosage several years ago, people used exactly that analogy. It’s hard to appreciate that analogy because therapy is not this little unit of a pill or a tablet, it's a complex interaction between people. When we think about dosage, sometimes as clinicians we can decide dosage for our treatment, but sometimes it may be imposed upon us by an external source, such as our workplace or healthcare funder. And while it's important that we take guidance from the literature to determine dosage, I am not sure that that always happens. Rob, you are both an aphasia clinician and an aphasia researcher, how did you get interested in thinking about dosage as it relates to aphasia treatment?
Rob: I am a clinician by training, and that's really the viewpoint with which I started. Like you mentioned, I worked primarily in outpatient rehab settings, where most of the individuals who came into our clinic were home from the hospital, and they were working to recover from a recent stroke or traumatic brain injury or brain cancer, or some similar life-changing event. I think you're right, that practical dosage in a clinical setting like this is some combination of the clinical decision-making that we do as expert speech-language pathologists, and then all of these real-world constraints around us such as insurance, clinician availability, or the client's ability get to the clinic on a regular basis. I was fortunate to have excellent mentors and I'm going to acknowledge them. MaryBeth Kerstein, and Lisa Hunt and Missy Davis at Carolinas Rehab, were expert clinicians for me as a novice coming in. They really knew how to navigate their clinic, what they wanted to do from a clinical standpoint, and then what they were looking at in the insurance paperwork, and what to do when the patient said, “Well, I can only get here once a week”. My interest in dosage really comes from the perspective of, I've got this treatment, and it requires a lot of dosage and I want to fit it into a very narrow window of time. As a clinician you're grateful to have twice weekly sessions for six or eight weeks, and then you read a treatment study and it said that it provided treatment for 20 or 30, or even 60 hours. That's really hard to do in practice. So you know, we want to be confident that if I'm going to go with a treatment, if I'm going to choose it, I'm not wasting someone's time because I don't have enough of it for the treatment to be effective. And I'm also not wasting time by doing too much of it.
Janet: That's so important to think about Rob. You also mentioned something else, patient characteristics. Can an individual get to the clinic as much as they need to? Are they motivated to participate in this treatment? Those pieces must factor into your decision as well.
Rob: Sure, and you know, I think about some of our really high intensity treatments. Here at the Pittsburgh VA, we recently completed an ongoing study of semantic feature analysis which provides 60 hours of SFA. That's a lot of time to be doing a single treatment and so certainly motivation is a really important piece that we have to fit into the conversation about dosage.
Janet: As an aside, I'm sure you know, we're doing some investigation into motivation and what it means and how it works and how we can best use it in treatment, but it certainly is part of the decisions that you make when you when you select a treatment. I am glad that you're thinking about these pieces, because they're all focused on getting the most effective, efficient treatment that we can for a patient, and you're right, not wasting time or resources.
In your recent publication, Rob, you approach the topic of treatment dosage by identifying the gap between the dosage reported in research studies and the dosage used in clinical practice. By the way, the link to that paper is at the end of these Show Notes. It appeared in AJSLP so our listeners can access that paper and read your work for themselves. In that paper, you and your colleagues use the term voltage drop to describe this difference between research and clinical application. Will you explain the term voltage drop to us and describe how you see its relevance to aphasia treatment?
Rob: Sure, so voltage drop is this idea that when you take an intervention that worked in a controlled research setting, and we saw some good results, and then you implemented that scale in the real world. You give it to clinicians and while they might use it in their clinical practice, there can be a reduction in how effective that intervention is, right? The real world is messy, it's often hard to implement the research protocol with high fidelity, or there are good reasons to alter the protocol for individual situations, but we don't know how those alterations might affect the outcomes – this is voltage drop. This idea has been around in the implementation science literature for quite some time. I actually first heard this term on another podcast called Freakonomics, which is very different from what we're talking about today. It was in the context of how do you scale up social interventions like universal pre-kindergarten, and the challenges that come with finding something that works in one situation and trying to bring it to the whole country? And I thought, “Oh, this is exactly what I've been worrying about in our clinical practice world.” How do we take something that works in a small, controlled setting and make it work in larger settings throughout the country, in clinical settings? The term voltage drop seemed like a great way to motivate the conversation in our paper about dosage. If we can't implement the same dosage in clinical practice that we see in research, we could see a voltage drop in our treatment effectiveness for people with aphasia.
Janet: Right. I like that that term. Rob, as I was listening to you talk about this term voltage drop, it reminded me of phases in research, where you start out by demonstrating that the technique works in a research environment, and then moving it to a clinical environment to see exactly how it does work. I also thought about how we as clinicians need to be mindful that when we implement a treatment, if we can’t meet the conditions in the research treatment, if we aren't taking into consideration this potential voltage drop as we implement treatment, we may not be doing the best job for patients. Does that make sense to you?
Rob: Yeah, I think it's a really hard balance as a clinician. You might have treatment which you feel like would be particularly helpful for someone. But the literature says this treatment has been implemented for 30 or 40 or 60 hours in the research lab and you're looking at the paperwork for this person which says that they have 20 visits, and you're wondering how you're going to make that work? Should you use a different treatment that doesn't seem to have as much dosage in the literature, or should you try to fit that treatment into what you have with that person? I think those are questions we don't have good answers to yet and clinicians struggle with all the time.
Janet: Which leads me to my next question for you. As clinicians recognizing the situation, how should we use this concept of voltage drop as we determine an individual's candidacy for a particular aphasia treatment technique, and determine treatment dosage in our own clinical settings? That’s a loaded question, by the way!
Rob: That's a great question. I think this area of research has a long way to go before we really have any definitive answers. I think this idea of voltage drop right now perhaps is just something that can play a role in our clinical decision-making process when we go about implementing the aphasia treatment literature with our clients on a daily basis. For example, we often deviate from the evidence base in ways we think will improve our treatment outcomes, right? We personalize our treatment targets so that they're motivating and relevant for our client’s goals. We might integrate multiple treatment approaches together or provide two complimentary approaches at the same time to address multiple goals. These adjustments reduce how closely our practice matches the evidence base for a treatment, but hopefully they improve the outcomes. On the other hand, we often have to make these compromises that we're talking about and deviate from published protocols because of practical constraints in ways that could reduce effectiveness. Not being able to even approximate a published treatment’s dosage because of insurance or clinician availability or transportation has the potential to reduce treatment effectiveness. I think these factors probably should play a role in whether or not we choose a particular treatment approach. Maybe we use the difference in the published dosage versus what face to face time we know we're going to have to make a determination about how much home practice we suggest the person do. Or maybe we say there's just too big of a difference in what I know I can do with this person, and I need to think about other treatment options.
I'd also like to add maybe an important caveat here, which is that I don't know of any aphasia treatment, and I would love for somebody to email me and tell me what study I haven't read yet, but I don't know of any literature that has established an optimal dosage for even an average person with aphasia, and certainly none that say if you see a person with aphasia with a certain profile you need to provide at least X minutes of this treatment for it to be effective. Most of our evidence base tells us about the average effect size across participants for a single dosage. And it's really hard to extrapolate this information to make decisions about an individual person with aphasia.
Janet: I think you're absolutely right, Rob. I have not read a paper about optimal dosage for any kind of a treatment either. And one of the things that I was thinking about as you were talking is that I want to assure clinicians that we're in a messy world here trying to figure out dosage and intensity. I want clinicians to be able to continue to walk through their clinical decision-making without trying to figure out how all these pieces fit together in treatment. The words that came to my mind, as you were talking about strategies that clinicians might use as they decide whether they want to use a particular treatment or not, is mindful clinical decision-making. If you choose a treatment knowing that you cannot deliver the number of sessions that are listed in the research literature, then what are you balancing or what are you giving up in order to implement that treatment? It's mindful decision-making, as you apply a treatment. Does that make any kind of sense to you in terms of looking at dosage?
Rob: Yep. I think that makes a lot of sense. It brings up this idea to me of opportunity cost, right? Imagine a decision tree of things or directions you could go as a clinician, and every branch of that tree that you could take means that you don't get to take the other branch. This could be a paralyzing decision-making process if you try to incorporate too much, but maybe dosage is one of those key elements that you say, “I'm going to prioritize, making sure dosage is at least approximate. Maybe I can't get 30 hours, but I can get close, so I feel confident that's not going to limit my treatment’s effectiveness.”
Janet: I think it is important to pay attention to dosage. Don’t just proceed with random assumptions about dosage but pay attention to it as you're deciding to implement a treatment.
We've talked a lot about the background and the importance of dosage and mindful clinical decision-making from a clinical perspective. I hope our readers know by this time that that the comments you're making are based in science, so I want to talk for a little bit about your paper in AJSLP, if we can. I mentioned already that the reference is listed below in Show Notes that accompany this podcast, and our listeners can also find it by searching the ASHA publications website, and also your University of Pittsburgh website, on the Communication Sciences and Disorders page and the Language and Cognition Lab page. You have two methods in this paper, analyzing hospital billing data, and also conducting a scoping review of the literature. Without delving too far into the details, will you tell us about these methods and how they allowed you to then examine the research-practice dosage gap?9
Rob: Sure, I'm happy to summarize. I learned, you know, halfway through this project that I bit off quite a quite a bit of research. It was a pretty large project for me as a doctoral student! Our driving research purpose for this study was to estimate how well the typical dosage that was provided in clinical practice approximated what was provided in the research literature. There are two elements here, what's typical in clinical practice and what's typical in research. In particular, I was interested in outpatient clinical practice, because this is often the last stop in our rehabilitation medical model for people with aphasia, and it's where my clinical experiences had mostly been. To estimate dosage in clinical practice, we looked at billing data from a large regional provider in western Pennsylvania. Every time an SLP sees a client they have to bill a specific code to the insurance company for that visit. These codes are attached the electronic medical record and we were able to use resources in Pitt’s Department of Bioinformatics to extract these billing codes. We counted them all up for people with a diagnosis of stroke and aphasia who were seen by a speech-language pathologist. We looked to see how many were there? How often do they occur? Over how many weeks did they occur? We don’t, of course, know the extent to which these specific providers match the rest of the US or certainly not international clinics, but we felt like this was a good start, given the lack of information in the literature.
Then on the research side, we wanted to estimate the typical dosage for studies that had been published recently. If we looked back 30 years, we'd probably still be reading research articles, so we used a scoping review format because our research question was really focused broadly on dosage rather than the specific study designs, the quality of the studies, or the outcomes, we just wanted an estimate of the dose. I have to give a shout out here to Rose Turner, the librarian on our team at Pitt, who guided this aspect of the study, I strongly recommend anyone use a librarian for reviews like this, we could not have done it without her. We started with over 4500 study records which matched our search terms and we whittled them down to 300 articles.
Janet: That's a lot of work, Rob.
Rob: It was definitely a lot and I will say we have a team, right? This was not me, this was a team effort. We ended up with about 300 articles, which essentially describe the aphasia treatment literature over the past 10 years or so. These were not studies that were provided in the hospital, these are mostly community-based treatment studies. They didn't have any extras, like the people receiving treatment weren't also receiving a specific medication or some kind of brain stimulation, it was just behavioral treatment. We pulled the dosage out of these studies and then we compared them to what we found from our billing data.
Janet: I read the paper a few times, and I'm not unfamiliar with a scoping review or with gathering data from clinical records. I found myself as I was reading that paper thinking this must have taken you years and years and years, which of course, I know it didn’t, but your team really has, I think, produced a great paper that is going to be a good foundation for us to think about dosage.
That's a wonderful summary of the methods you used and anybody who reads your paper will appreciate the summary that you just gave. What messages did you glean from the data that you collected? I am thinking of the specific research conclusions, and also messages that maybe might help us as clinicians?
Rob: Sure, so I don't think it's a surprise to any clinician out there that there was a meaningful gap in dosage between the research studies we looked at and the billing data. This was particularly true for the number of treatment hours. Research studies provided on average about 12 more hours of treatment than we found in the clinical billing data. That's per episode of care. Think about a person who comes into the clinic, has an evaluation, receives a number of treatment sessions, and is discharged. On average, that episode of care has about 12 hours less than your typical research study. This largely confirmed our hypothesis going in that we would see a gap here. Interestingly, clinical practice seemed to provide treatment over a longer period of time. The total number of weeks was longer than what was typically done in research studies. You might take a conclusion away that in at least outpatient clinical practice, treatment might be a little bit more distributed over time and less intensive than treatment provided in our research literature.
I think it's important to highlight that this is a really rough comparison of dosage, right? Billing data are not really specific to the clinician patient interaction. It's just the code that the clinician punches into their software when they're done. We've glanced over some important aspects here that we just weren't able to look at. For example, dose form, or how many times each element of a treatment was completed, is not something our study was able to look at. These are some of the most important aspects of treatment, and what I try to do as a clinician, such as goal setting, and counseling and education, the time working on our communication goals outside of impairment focused tasks. Those elements aren't often part of treatment studies, but they're absolutely part of clinical practice, and they take a lot of time. That's an unaccounted-for difference that could mean that we've underestimated this gap and dosage. On the other hand, clinicians often assign home practice; we work on something in the face-to-face session and then I say, great, you've done an amazing job, I want you to practice this 20 minutes a day until the next time you come in, something like that. We didn't have a way of tracking home practice in our study. Perhaps home practice is an effective way of making up this dosage gap. But we're not able to understand what role it might play based on these data.
Janet: I think you're right about that, and it makes a whole lot of sense. This is a start in our direction of trying to really understand more carefully what dosage means. Does it mean this large thing? Does it mean very specifically, how many times are we delivering the active ingredient in a specific therapy? There's so much more that we need to know, and I think you have figured out by now that I think dosage matters, I think it matters a lot. I think it matters a lot more than we've ever really paid attention to. I know also, and you've certainly described this, every day in clinical practice we make decisions about an individual's candidacy for rehabilitation, including that what we think as clinicians is the best match between a treatment, a patient's personal and aphasia characteristics that they bring to the rehabilitation enterprise, and the likelihood of an optimal outcome. If we get it wrong, because of a mismatch in dosage, we may not successfully translate research into practice, and we may not make that much of a difference in our patient's life, or at least we may not make as much difference as we hope to. In the case of a potential mismatch, how do you see that affecting our clients, their families, and our healthcare system, because we do have to think about all of these pieces of the aphasia rehabilitation enterprise.
Rob: I think you're right you know, this is just a start. When I started my doctoral program at Pitt Dr. Evans and I were working on grants, and we would always write a statement like, treatment services are limited, and then I'd go try to find the citation for that line, and it's hard to find. Dr. Simmons-Mackie’s White Paper is fantastic and provides a little bit of evidence to that regard but there aren't a lot of numbers. So, I think you're right that this is not the end of the story, I'm hopeful this study is a start. I think if you buy into this idea that too much of a gap in dosage could result in voltage drop in our treatment effectiveness and poor outcomes, I'm concerned that our ability to help people with aphasia and their families recover and adjust and thrive with their new reality is diminished in real world clinical practice. That's a big concern for me, and that's the reason that I am a speech-language pathologist and working with people with aphasia. I think that's something we need to understand better as a field. I'm also aware that when somebody decides to come to treatment, they're dedicating time and energy to themselves and trusting us as clinicians that we know how to best use their time and energy. The time spent coming into the clinic or doing home practice could just as easily be spent with family or friends or in other fulfilling activities, so I want to be respectful of their time.
With regard to how this could affect our health care system, I don't know that I have a great answer for you. Sometimes I wonder whether the current medical model is really a good fit for chronic conditions like aphasia. The gap in dosage might just be one manifestation of the challenges that clients and families and clinicians face every day, in figuring out how to make affordable and effective and motivating treatment options available for people long term. That's got to be a priority for us moving forward, because I'm not sure that our current model really fills that need.
Janet: Rob, I agree with you on that, and I'm thrilled that you and your colleagues are making this initial attempt to try to figure out how we can best match the treatment and the clients in terms of dosage, to achieve the optimal outcome that we possibly can.
You know, Rob, that I think that this conversation is fascinating, and we could talk all day. My belief is you and your team have just scratched the surface about treatment delivery information that we must be mindful of, in both our research and our clinical practice. A lot today that we've talked about really relates to clinical practice, but I imagine there are just as many thoughts or concerns or cares that we need to take when engaging in a research protocol to evaluate the success of a treatment.
Rob, as we draw this interview to a close, what pearls of wisdom or lessons learned do you have for our listeners, both researchers and clinicians, about dosage and aphasia rehabilitation, bridging the research-practice dosage gap, and reducing the voltage drop as we implement aphasia treatment.
Rob: Yeah, it's a tall order.
I don't think there's a quick fix, certainly, but I I'm going to summarize and expand on some of our recommendations from the paper. One thing that's important, I think, as we move forward is that, as researchers, we need to be really thoughtful about our selection of dose. As you mentioned, with regard to the stage of research, maybe our selection of dosage in early-stage research reflects our underlying research questions and issues of statistical power and funding constraints. For later stage research that's starting to think about clinical outcomes, we need to provide a clear justification for deviating from a dosage that's not attainable in clinical settings. In the same vein, I think as researchers we can do more to provide easily accessible and hopefully free materials to clinicians to facilitate home practice and to augment the limited face-to-face time that clinicians might have with their clients. Software and app development are getting there, and I think they're improving how easy it is to do home practice. To me a treatment study that you want to be out in the real world is only going to be successfully done if you really give clinicians easy access to tools where they can implement it. I know, just like many clinicians know, their time is really limited particularly between seeing patients, and so I don't want to make them do a whole lot of work to implement my intervention.
The second recommendation from our paper is that we need more research on the role of dose. We've talked about one challenge in this line of work, which is that dosage requirements are probably a function of an individual's language profile, almost certainly a function of their individual language profile, and their individual circumstances. If you compare one dose to another in some group trial, it only gives you so much information about what dose is best for a given individual. I think this is a problem our field is going to have to solve. Our lab is working on one solution that we're really excited about, which is to base treatment dosage not on the number of minutes, or how often you see someone, but on their real time performance on individual treatment items, like their ability to produce a specific sentence in script training or name a word, if you give them a picture. Our lab is not really thinking about dosage in terms of treatment time, right now we're thinking about dosage at the item level individually for each person. We're finding some strong preliminary evidence that complex algorithms can tailor item level dosage to real time performance and can make treatment potentially more effective and more efficient in terms of how much we can do in a period of time. But we have a lot more work to do, establishing this in a larger sample size and making sure that it translates well to clinical practice.
This brings me to the last recommendation, which is we need more research that looks at how can we implement our research in clinical practice. I believe there was a paper that came out in AJSLP recently (Roberts et al., 2021) which found that 1% of studies published in the Asha journals were implementation focused. I think that number is too low. We need more implementation-focused research that has contributions from all stakeholders, people with aphasia and their families and clinicians and researchers. It's going to take a team working together to ensure that we can translate our evidence base to clinical practice without voltage drop. I think that's where I would love to see our field headed.
Janet: Rob, I love the recommendations from your paper and the way that you just described them. It's exciting to be in this time in our field, where people like yourself and your team are thinking about the idea that we've got some great therapies, now how do we deliver them in ways that are sensitive to the needs of the clinician and the needs of the client and delivered in a mindful way of clinical decision-making.
Thank you for all of those recommendations and for your work. You're going to do more, right?
Rob: Thank you for having me. Yes, there will be more.
Janet: This is Janet Patterson, and I'm speaking from the VA in Northern California, and along with Aphasia Access, I would like to thank my guest, Rob Cavanaugh, for sharing his knowledge and experiences with us as he and his colleagues investigate treatment parameters, including dosage, in aphasia rehabilitation. We look forward to seeing many additional articles on this topic from Rob and his colleagues.
On behalf of Aphasia Access, we thank you for listening to this episode of The Aphasia Access Conversations Podcast. For more information on Aphasia Access, and to access our growing library of materials, please go to www.aphasiaaccess.org. If you have an idea for a future podcast topic, please email us at email@example.com. Thank you again for your ongoing support of Aphasia Access.
References and links from this episode:
University of Pittsburgh
Department of Communication Sciences and Disorders
Language Rehabilitation and Cognition Lab
University of Pittsburgh
Department of Communication Sciences and Disorders
Cavanaugh, R., Kravetz, C., Jarold, L., Quique, Y., Turner, R., & Evans, W. S. (2021). Is There a Research–Practice Dosage Gap in Aphasia Rehabilitation? American Journal of Speech-Language Pathology. https://doi.org/10.1044/2021_AJSLP-20-00257
Roberts, M. Y., Sone, B. J., Zanzinger, K. E., Bloem, M. E., Kulba, K., Schaff, A., Davis, K. C., Reisfeld, N., & Goldstein, H. (2020). Trends in clinical practice research in ASHA journals: 2008–2018. American Journal of Speech-Language Pathology, 29(3), 1629–1639. https://doi.org/10.1044/2020_AJSLP-19-00011