How much treatment is enough?
Ah, this one is a doozy.
Short answer: it depends entirely on what you’re treating, and how. And even then, we often don’t know the answer. You will not find definitive answers here (or in the research literature to-date). What you will find is guide posts—pushes toward certain levels of intensity in certain situations. So if you’re comfortable with “squishy” answers, please proceed.
Let’s start with some current trends: what are most SLPs doing? Unfortunately, research suggests that SLPs tend to take one scheduling option and apply it across their entire caseload, regardless of individual student profiles. For example, school-based SLPs provide service predominantly 2–3 times per week, in pull-out groups (Brandel & Frome Loeb, 2011). Some predict that this is due to habit and large caseloads (Chiang & Rylance, 2000); others predict it’s an artifact of the IEP process and the way school SPED systems are structured (Case-Smith & Holland, 2009; Clark & Flynn, 2011). But, whatever the reason, therapy a couple times per week for 20–30 minutes most definitely represents the status quo, particularly for our clients with mild–moderate impairment (Mullen & Schooling, 2010). And one thing we do know is that doing the same thing for everybody is not individualized education, and not supportive of client’s individual needs. So if you have a diverse caseload, but with clients/students all on the same schedule, this may be an area of your practice where an audit is warranted.
What about trends in the scientific literature? Historically, treatment research in our field has been characterized by a brief-but-intense model: meaning, treatment sessions 3–5 times per week for just a few months. Also, intense treatment is often recommended (e.g. Gersten et al., 2008; Nippold, 2012). Warren et al., 2007 note: “The field of communication and language intervention has only recently emerged from a lengthy period of developing various intervention techniques and testing them… for short durations.” And just as it’s easy for clinicians to slip into patterns because it works best within the limitations of their system (e.g. what our schools “force” us to do), scientists face systematic barriers, too—intense treatment may elicit more reliable effects, and brief treatment is usually more time- and cost-effective for the research team.
The good news! Fortunately, we’re starting to see more and more papers that compare various treatment intensities to one another (this is the only way you actually know what works). Also, we’re seeing a lot more treatment intensities in the literature that closely match what’s done in clinical practice (yay!). We’ll review this research, below.
But first, some terminology:
Note that changing any of these things, above, could matter for treatment outcomes because it effects the cumulative intervention intensity. For example, you could hold session length (30 minutes), frequency (twice weekly), and duration (12 months) constant, and only change dose—that is, change how intense your individual sessions are, and make massive changes to your client’s progress. Note also that “dose form” refers to the exact type of treatment you’re giving, and that can make a difference as well! And sometimes dose isn’t just what a child does, but what s/he’s exposed to (Justice, 2018). So do keep in mind: it’s not just about schedule, frequency, or what the grid says. It’s about what you do in your sessions that matters (perhaps more than anything else).
Second—you must understand what it means (or doesn't) when a study uses a certain treatment intensity:
Just because a study shows that an intervention was done on a certain schedule (e.g. 5 days per week, one hour per day), does not indicate that this is the optimal treatment intensity, unless the scientist also tested higher or lower treatment intensities. All it means is—“Hey! It looks like treatment at this intensity works well…” And sometimes that intensity is based upon years of other studies (which you may be able to compare to one another, in order to make better decisions about treatment intensity). Other times, with very novel treatment methods, it can simply be the scientist’s best guess, based upon other studies with similar methodology or looking at what tends to work in clinical practice. Thus, single studies don’t necessarily prescribe of what the clinician should do. Instead, we start to know what intensity is best when we (scientists and clinicians) either test various intensities within a single study, or start to compare data across many studies and look at effect sizes.
Third—we’re focusing on intensity, here, but scheduling is a closely related topic:
Scheduling options may include things like:
- Traditional weekly = same schedule, every week (e.g. 2 times per week for the year)
- Receding = start high, then back off (e.g. 3 times per week for two months, then once per week for 4 months)
- Cyclical = a repeating cycle (e.g. 3:1 model, where you could treat twice per week for three weeks, then off for a week, then the cycle repeats)
- One way to make sure you’re making good individualize decisions, is to make sure you’re not just applying a traditional weekly schedule to everyone, always! Get creative with that grid.
- And note—you can increase treatment intensity without changing schedule at all—by changing what you’re doing in the therapy room to increase dose. Or by structuring the session in a way that maximizes learning. Or by getting help outside the therapy room—e.g. adding digital support options (e.g. apps), increasing support from other staff, involving family, etc.
OK, back to intensity! So how much is needed?
It varies per what you’re working on, how you’re working on it, and who you’re working with
(can’t say that enough…)
What about for pediatric speech sound disorders?
There is no great in general data for pediatric speech sound disorders. But here are some things we do know:
Several studies have examined treatment intensity for multiple oppositions approach, specifically, and found that:
- “a minimum does of more than 50 trials and duration of at least 30 sessions is required… to be effective” (Williams, 2012) (achievable in twice weekly 30 minute sessions per this paper)
- greater intensity is needed for more severe speech sound disorders (Williams, 2012)
- intensity may need to change over time—e.g. heavier in the beginning of a treatment program (Williams, 2012)
- preschoolers make better gains with three-times-per week therapy for a shorter duration than once-per-week therapy for a longer duration (even with cumulative intensity being equal) (Allen, 2013)
- Multiple oppositions has the most intensity analyses behind it, but that doesn’t mean other approaches have nothing! Check out this ASHA Conference talk from 2011.
Also, in the treatment of speech sound disorders, it’s important to consider general principles of motor learning. For example:
- Yoder et al. (2012) review evidence suggesting that “generalization and retention” are better with distributed compared to massed treatment (massed = trials clumped together; distributed = trials spread out over time)
- Manes & Robin (2012) point out that it’s not just about how much you provide the child, but how—e.g. random practice is better than blocked practice (except for when the task is very difficult) and providing too much feedback isn’t good for learning (though you may need more feedback for complex tasks, and less for simple tasks).
Then there’s also some recent literature on childhood apraxia of speech (CAS), suggesting:
- Minimum of twice-per-week treatment required for preschoolers with CAS to make gains (Namasivayam et al. 2015)
- ReST (one of our most evidence-based approaches) is typically provided four times per week for three consecutive weeks, but twice a week for six weeks works almost as well (Thomas et al., 2014)
- Good treatment outcomes, per the current literature base, are yielded from interventions provided 2–3 times per week, up to 60 minutes per session, with at least 60 trails per session (Murray et al., 2014)
- Per-session dose is twice as high (or more) in studies of CAS compared to other speech sound disorders (Murray et al., 2014)
At present, the best we can do as clinicians in determining the optimal intervention intensity for a child with speech sound disorder is to look to the research literature on what has been shown effective for children with a similar profile (ask: What type of therapy should I try?), approximate the intensity that has been demonstrated effective for that particular type of therapy, then take individual client data to determine if a different intensity may be warranted. Want to read more? I’d recommend: Kaipa & Peterson, 2016.
What about for pediatric language disorders?
“… today we have very little guidance, if any at all, as to how to configure dose when serving children with language disorders.” Justice, 2018
Yes, so unfortunately, research on treatment intensity for language and literacy is a bit all over the place… (note: grouping literacy in with language, here, because many of these studies are targeting both)
You’ll find studies showing lower intensity is just fine:
- once per week vs. three times per week didn’t matter (Ukrainetz, 2009)
- once per week vs. five times per week didn’t matter (Fey et al., 2012)
- Interested in more examples of lower-intensity treatments? Try our review of Wright et al. (2017) here.
You’ll find studies showing higher intensity is better:
- intervention four times per week better than twice per week (Al Otaiba et al., 2005)
- for preschoolers, “…more treatment is associated with better outcomes…” (read here)
You’ll find studies that simply can’t find a difference…
- The Language and Reading Research Consortium et al. (2016) found, surprisingly, that doubling number of sessions per week of vocabulary instruction didn’t improve children’s vocabulary
- Balthazar et al.’s (2014) study of adolescents with language disorder found good results treating complex sentences—regardless of if it was provided once vs twice per week
… or show that there’s only a difference when dose is examined:
- Schmitt et al. (2017) found that once-weekly sessions “work” for children with language disorders as long as the sessions are highly productive, with a high dose
- And—side note—our language treatment often isn’t highly-productive as we’d like, because we’re dealing with behaviors and such (Schmitt et al., 2017)
- The Justice et al. 2017 paper is also a great one for examining this topic—read our review, here.
… or when you measure client variables:
- children with greater interest in various play objects benefitted more from higher therapy doses (Warren et al., 2007)
- children with certain diagnoses benefitted more from higher-dose therapy than others (Yoder et al., 2012)
… or when you measure clinician variables:
- “variance in child language and literacy gains over the course of an academic year is at least partially attributable to between-SLPs differences” (Farquharson et al., 2015)
In addition, you’ll find plenty of discussion on how it’s not just about dose, or the client, or the clinician, but the therapy itself:
- “…outcomes are influenced by both the intensity of an intervention and the ingredients that make up an intervention…” (Baker, 2012)
- Zeng et al. (2012) state: “… the amount of intervention does not relate directly in a linear fashion to outcome, suggesting that it is the quality of the intervention received that is important, not the volume.”
- Also, check out Eisenberg (2014) for an excellent discussion on what the therapy itself should look like, along with some further review of treatment intensity
Then, another thing we’ve been seeing increased discussion of lately is “spacing”:
- Spacing refers to spreading therapy out over time (e.g. the course of a year) instead of a more brief-but-intense model (e.g. four times per week for three months). The best description I’ve seen on spacing is this one (brand spankin’ new paper!). Justice states, “Both theory and evidence suggest that spaced, infrequent treatment sessions can be as effective as more frequent treatment sessions if the infrequent sessions contain a high level of dose, representing children’s exposure to the presumed active ingredient of therapy.”
- Others have also found that expressive language treatment works better when spaced out over the course of weeks, instead of when provided daily, with dose held constant (Smith-Lock et al., 2013)
Wow. You can go get a snack (or drink) now. That was a lot... So, clearly there are many variables to consider. And notice how we haven’t even begun to discuss other things SLPs may be working with these same clients, including fluency, social skills, AAC… all which add another level of complexity to determining how and how much treatment to provide.
I think it’s also important to note how we, as clinicians, feel about this information. Does the above information make you feel better-prepared? Informed? More confused? Or (hopefully) motivated to participate in discussions about what we should consider next, and even begin to take part in data collection so that we can start to figure this stuff out?!
One of the aspects of our jobs that I think makes our work immeasurably challenging is that we work with people: their bodies, their minds, their environmental circumstances... Not chemicals. Not structures. Not things that can be predicted by the physical laws of nature. Shhh!!! It’s only us here, so we can go on pretending like our jobs are far more difficult than others’; just don’t tell the chemist down the street I said that. So, I’ll leave you with a quote from Baker (2012), noting that this is hard, and always will be, no matter how much data we collect over the upcoming decades:
“…the study of intervention intensity is complicated because it involves real people—individuals with unique characteristics, values, and preferences." (Baker, 2012)
Then also this quote. Because it feels good to know that we, as SLPs, are mostly on the right track!
“The typical schedule for school-based speech–language services involves once- or twice-weekly sessions for the entire school year (Blosser, 2012). I see nothing in the research evidence to suggest that we should not use this scheduling pattern—and the research may actually favor this type of distributed scheduling—as long as a sufficient amount and rate of learning episodes... can be provided within each session.” (Eisenberg, 2014)
Now go hug an SLP while s/he tries to figure out how many times per week to enroll that child in therapy.
Answer provided by:
Meredith P. Harold, PhD, CCC-SLP
owner of The Informed SLP
Meredith P. Harold, PhD, CCC-SLP
owner of The Informed SLP