July 09, 2013

SLPs Blogging about Research - July edition

Once a month SLP Bloggers are blogging about research related to the field of speech pathology. You can learn more here.

Imagine this scenario: You're prepping for an initial IEP meeting for a preschool student with moderate phonological needs, and you need to determine the frequency of services you will be recommending at the meeting. What do you suggest? Two 30-minute sessions per week? Three 20-minute sessions per week? Five 10-minute sessions per week? Many factors can influence this decision including the severity of the child's needs, the child's age and grade, parental input, your professional judgment...How do we as SLPs - the communication professionals on the IEP team - make sound decisions about frequency and intensity of services when so many factors can influence that decision? I reviewed the following article, hoping to get a little clarity on the subject.


by Melissa M. Allen
In the words of the author, this research study aimed to investigate "...the effect of intervention intensity on phonological production skills for preschool children provided the multiple oppositions approach." In the multiple oppositions approach, treatment targets are selected which are as different as possible in place, manner, and voicing in order to have a greater overall impact on a child's phonological system.

The author had three main questions:
1) Does frequency of phonological intervention affect the outcome?
2) Does duration of phonological intervention affect the outcome?
3) Does either frequency or duration lead to continued gains during a maintenance period?

A total of 54 children ranging in age from 3 years 0 months to 5 years 5 months were chosen for this research study. All met state eligibility requirements for an IEP, had at least 6 sound errors from three different manner classes, passed a hearing screening, presented with typical speech structures and functions, and did not present with childhood apraxia of speech. Of these children, 72% were boys, and 28% were girls.

There are four main factors that can influence the total intensity of an intervention. The author does a nice job defining these terms:

dose = the number of trials or responses per session
dose form = the contexts of the activities (i.e. child-directed vs. clinician directed; play-based vs. drill-based)
dose frequency = the number of sessions in a designated period of time, and the length of each session (for example, one 30-minute session per week)
total intervention duration = can be a specific number of sessions, or a length of time 

The current study controlled the dose and dose form, but manipulated the dose frequency and total intervention duration, resulting in three separate study groups:

Group P1 received one 30-minute session per week for a period of 24 weeks, followed by 6 weeks of no treatment
Group P3 received three 30-minute sessions per week for a period of 8 weeks, followed by 6 weeks of no treatment
Control Group received a storybook intervention targeting print awareness (one 30-minute session per week for a period of 8 weeks)

All subjects were assessed prior to treatment, at the end of 8 weeks, and following the 6 weeks of no treatment. Subjects in the P1 group were also assessed again at the end of their 24 weeks of intervention. Percentage of Consonants Correct in single words was measured using the GFTA-2.

Sessions consisted of sharing rules explaining phonemic constraints (such as singletons vs. consonant clusters), familiarization of target words, practice of contrastive pairs, and summarization. Productions moved from single words to words in carrier sentences. The dose for each session aimed to be approximately 80 responses per session. The author provides additional details regarding criterion for moving along through the phases of intervention.

Looking at the author's original three questions, results were as follows:

Does x1/week or x3/week make a difference after 8 weeks?
- Yes! The intervention group that received x3 sessions/week for 8 weeks significantly outperformed the group that received only x1 session/week for 24 weeks.
- Interestingly though, only the x3/week group outperformed the control group. The x1/week group did not perform much different than the control group. So in this instance, receiving intervention x1/week was not much different than receiving no therapy at all!

Does x1/week or x3/week make a difference after 24 weeks?
- Yes! When looking at the results in this light, the x3/week group again significantly outperformed the x1/week group. This group did not receive as many weeks of intervention, but they had more frequent sessions per week.

What about after the 6 week maintenance period?
- In this case, both treatment groups showed improvement during the maintenance period, but these gains were not significant for either group.

My Thoughts:
*The researchers used the GFTA-2 to measure percentage of consonants correct in single words. Perhaps a spontaneous speech sample could have provided a better picture and even better data of each child's true abilities and their response to intervention.

*I loved that the interventions occurred in the children's Least Restrictive Environment (according to their IEPs). The treatment sessions were provided in preschools, Head Start classrooms, daycare, and family homes!

*Examining the results, it looks like (in this particular instance) more frequent sessions can result in a shorter length of time children could possibly be in therapy. Makes sense to me. If we provide a period of really intense instruction for our students (especially younger ones like in this study), perhaps they'll respond and be ready to exit services sooner. On the other hand, ages 3-5 are a bit young for a lot of speech sound to be appropriate therapy targets. But that early support can really provide a strong platform for later development, and perhaps those students wouldn't need services down the road.

*No homework was provided for any of the groups. That extra boost from home can definitely increase carryover and treatment outcomes.

*I feel there is definitely a need in the speech therapy world to establish treatment intensity guidelines. This research study does a nice job adding to the information and previous research that is out there. Most treatment protocols have established frequency/intensity parameters, but honestly, these aren't always feasible in the 'real world'. 

*The fact that the x1/week group barely showed any difference over the group receiving no treatment threw me off. I've always believed 'therapy is better than no therapy', but is this truly the case?

*Keep in mind that these results only look at the effects of treatment intensity when using the multiple oppositions approach, and only with preschool children. Other treatment approaches may have completely different outcomes if subjected to the same methods. Follow-up studies need to be done measuring treatment outcomes for other intensity variables, such as dose form.

How This Will Transfer to My Practice:
As the author stated, this study provided "...an initial investigation into the manipulation of one intervention intensity variable for one phonological intervention approach." More studies need to be done, manipulating additional treatment variables for additional treatment approaches. Perhaps then as SLPs we will have a 'quick reference guide' of sorts to help us make treatment intensity decisions. Of course, even then, we'd all have 'exceptions to the rules' on our caseloads :) Until then, keep on keepin' on, use your professional judgement and clinical expertise to guide your treatment decisions, and keep reading the current research to help you 'therapize' those kiddos to the best of your ability! 

Allen, Melissa M. (2013). Intervention Efficacy and Intensity for Children With Speech Sound Disorder. Journal of Speech, Language, and Hearing Research, 56, 865-877.

What do you think? Did this research intrigue you? Are you pondering your own therapy methods and procedures? What research topics would you like to read about in the coming months? Head over to Talks Just Fine to see all the other participants and read their research reviews.

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