Research Tuesday: What's the Deal with Speech Disorders, Language Disorders, and Reading Disabilities?

Ok, so before I delve into the question I ask in the title, I want to first give a little intro to this Research Tuesday thing, which is why I'm asking the question and how I found the answer. SO. Research Tuesday is a once-a-month event where SLPs around the world (!) write blog posts about research that is relevant to them. The posts go up on all of the different blogs on the second Tuesday each month, and then Rachel over at Gray Matter Therapy rounds 'em all up on her blog and does a summary post, like this one for March. I thought I'd give it a whirl since a) I like to be associated with smart people doing smart things, b) I get a little rush when I say, "Well, the literature tells us . . .", and c) I can't remember the last time I read a research article all the way through.  

I took the "recent research in the field that is pertinent to their scope of practice" line seriously and thought about what I'm doing right now that I'd like to know more about. I currently have a placement in a Middle School with pretty intense linguistic and cultural diversity, so I started with a search on ASHAWire for new research on working with English Language Learners (ELLs). Unforch, the pickin's were somewhat slim, so I made a mental note to go back to school to get my PhD and do clinically-relevant ELL research, and then I started a new search related to Middle Schoolers. I came across Reading Skills of Students with Speech Sound Disorders at Three Stages of Literacy Development (Skebo, C. M., Lewis, B. A., Freebairn, L. A., Tag, J., Ciesla, A. A., & Stein, C. M., 2013) from Language, Speech, and Hearing Services in Schools and was intrigued enough to dive in. 

The purpose of this study was to look at the influence that a variety of linguistic and non-linguistic skills have on reading development over the course of a student's academic career, with a particular focus on those with Speech-Sound Disorders (SSDs) and/or Language Impairments (LIs). The authors cite a large body of evidence that supports that students with speech and language disorders are in fact at higher risk for having Reading Disabilities (RD) as well. It should come as no shock to anyone that phonological awareness, overall language ability, vocabulary, and non-linguistic cognitive skills are predictive of various aspects of success in learning to read. The team responsible for this article wondered, though, which sorts of linguistic and non-linguistic skills predict success at 3 different points in reading development -- Chall's (1983) Stage 2 (ages 7;0-8;11 ), Stage 3 (ages 10;1-12;11 ), and Stage 4 (ages 14;0-17;11 ) -- and whether the predictive value of any given skill was the same for a typically developing student and a student with a SSD and/or a LI. 

The study took 461 students, both typical and with speech/language disorders, and essentially tested the living daylights out of them. Each student was given the Goldman-Fristoe, the Elision subtest of the Comprehensive Test of Phonological Processing, the CELF-3, the PPVT-III, the EOWPVT-R, 5-10 subtests on the WISC-III or the WAIS-R, the WIAT and the Word Identification (WI) and Word Attack (WA) subtests of the Woodcock Reading Mastery Tests-Revised. Over 2 sessions. Oosh! They then took all of the results, paired them with the demographic info for each participant, and did a whole bunch of fancy statistical analysis that I probably could have understood 15 years ago but was a smidge over my head today. 

All of that maths told the researchers that . . . 

• Students with combined SSD and LI performed significantly more poorly than their typically developing peers or their peers with only SSDs across all 3 literacy stages.
• Not surprisingly, these same SSD+LI kids were at greater risk for reading difficulties than students with SSD only. 
• No significant differences were found between the students with typical language (TL) and SSD-only groups across literacy stages. In general, students with SSDs were more similar in performance to the TL kids than to the SSD+LI participants. 
• Students with SSD-only may be able to rely on vocabulary and overall language abilities for both decoding and reading comprehension to make up for their phonological awareness deficits. Students with combined SSD+LI may be at a greater disadvantage because they have deficits in both phonological awareness and overall language skills. A double whammy, if you will. 
• "Overall Language" skills were the most predictive factor influencing both decoding and reading comprehension for students with SSD+LI across reading stages. Middle School students relied on phonological awareness skills as well, while High School students relied on vocabulary skills. 

• Students with SSD+LI differ in predictors of literacy skills from SSD-only and TL students. 

The authors conclude the article by saying that SLPs are uniquely qualified to address both the foundational skills and the later compensatory strategies that struggling readers with speech-language impairments have. Is it just me or are we "uniquely qualified" to do a ton of stuff?! Anyhoo, they also stress the importance of SLPs being familiar with the path of typical reading development and with the influence different factors have at the different stages of learning to read. 

Sooooo, what exactly is the deal with speech disorders, language disorders, and reading disabilities? And, maybe more importantly, what's that got to do with me, the SLP? The conclusions in this article supported the previous findings of others, showing that there is indeed a relationship between having a speech-language impairment and having difficulty learning to read. They also took it a step further and demonstrated that there are certain factors that influence success more than others, and that those factors change over time. It seems to me that the SLP who focuses on "overall language," with a particular eye to the stage of reading their student is in, would be supporting both the language and reading development of their student/client. Skills like identifying prefixes and affixes, knowing typical word order in sentences and sentence order in paragraphs, tricks for finding context clues, and the all important vocabulary (my borderline obsession) would all do double duty in helping students with both their oral language skills and their reading skills. I can think of one student on my MS caseload who is an emerging reader and fits the SSD+LI profile. Maybe we'll experiment with doing some quickie phonological awareness warm-ups each session. I'm curious to see how he does!

Now, off to find an article for next month!