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3.2 Early Screening of Reading Risk

"Dyslexia is a neurobiological disorder. Research has shown that brain plasticity decreases through childhood. It takes four times as long to intervene in fourth grade as it does in late kindergarten (NICHD) because of brain development and because of the increase in content for students to learn as they grow older. Children at risk for reading failure can be reliably identified even before kindergarten (Gaab, 2017). … Struggling readers who do not receive early intervention tend to fall further behind their peers (Stanovich, 1986)."

– International Dyslexia Association, 2017

Universal screening procedures, if designed properly, will include the assessment of the skills that are the most predictive of later reading success or failure. Current research into the early identification of dyslexia suggests that children at risk for dyslexia can be identified early when intensive interventions are the most effective. Children at risk for reading failure can be reliably identified even before kindergarten. “Deficits in phonological awareness, automatized naming, verbal working memory and letter knowledge have been shown to be robust precursors of dyslexia in children as young as age three” according to Dr. Nadine Gaab, a leading researcher of the identification of early reading risk. Dr. Gaab, who is an Associate Professor at Boston Children’s  Hospital and Harvard Medical School, recently described early screening with a with a medical analogy:

The general idea here is not to diagnose children in preschool but to identify children “at-risk” to develop reading impairments (not just dyslexia). I often use an analogy from medicine for the argumentation: We are screening people for high cholesterol, which would be an increased risk to develop heart disease. We are not trying to diagnose people who present with high cholesterol with heart disease. If someone has high cholesterol and therefore is at-risk to develop heart disease we then provide ‘evidence-based response to screening’ which, in this case, would be prescribed exercise, dietary changes, maybe medication. The goal here is to prevent heart disease and not to diagnose earlier. It is hoped that fewer people then end up with a diagnosis of heart disease or if they do, it will be less severe since they already changed their diet, started exercising, take medications, etc. We want to move “from a deficit-model to a preventive model.” It’s the same with reading impairments. We want to identify preschoolers at risk but not diagnose them with dyslexia in preschool. Then you put great ‘evidence-based response to screening’ in place ... so that their risk to develop dyslexia decreases OR if they develop reading problems, it will be less severe since they already had remediation/intervention since preschool. 
-Retrieved from email communication via Spelltalk listserve (January 15, 2019)

Myths of Early Screening

Dr. Gaab has intensively studied the issues related to early identification of reading risk. In a recent article published by the International Dyslexia Association, she described three common myths associated with early screening for children at risk for dyslexia. The myths are excerpted from the article It’s a Myth That Young Children Cannot Be Screened for Dyslexia:

MYTH 1: Signs of dyslexia can be seen only after two to three years of reading instruction.

While a diagnosis of dyslexia currently requires repeated failure learning to read, this does not mean that early signs of dyslexia cannot be observed in preschool (or possibly earlier). Deficits in phonological awareness, rapid automatized naming, verbal working memory, and letter knowledge have been shown to be robust precursors of dyslexia in children as young as age three (Puolakanaho et al., 2007).

A recent study of more than 1,200 kindergartners in New England not only identified six independent reading profiles, including three dyslexia risk profiles, but also showed that these reading profiles are remarkably stable over a two-year window (Ozernov-Palchik, in press).

Furthermore, studies involving brain measures, such as electroencephalography or magnetic resonance imaging, have shown that the brain characteristics of individuals with dyslexia can be observed as early as infancy and preschool, especially in children with a genetic risk for dyslexia.

A longitudinal dyslexia study in Finland, which followed children from birth until age 8, showed that early differential brain measures could distinguish at-risk children who later developed reading problems from those who did not (Leppanen et al., 2010). Additionally, several studies have shown alterations in white matter (the highways that connect two brain areas and enable fast information flow) in young pre-reading children who subsequently developed a reading disability (Wang et al., in press; Kraft et al., 2016).

These studies suggest that these children are stepping into their first day of kindergarten with a brain less optimized to learn to read. Why wait three or more years before we give them access to additional resources essential for improving their reading performance?

MYTH 2: Even with early screening, early intervention is not effective.

It is certainly true that most reading interventions are designed for older children who have been struggling for some time. However, converging evidence points to the importance of high-quality classroom reading instruction in early grades and early interventions for at-risk students (e.g., in a small-group setting) to improve the effectiveness of remediation (Blachman et al., 2004).

A meta-analysis comparing intervention studies of at least 100 sessions reported larger effect sizes in kindergarten and first grade than in the later grades. Furthermore, a meta-analysis across six studies revealed that when at-risk beginning readers received explicit and intensive instruction, 50 to 90% of these children reached average reading performance levels (Torgesen, 2004).

Without high-quality instruction and intervention, early reading problems can manifest as serious reading disabilities later on (Stanovich, 1986). Moreover, several studies have shown that the brain’s ability to change and adapt in response to experience (brain plasticity) decreases throughout the childhood years (Johnson, 2001; Johnston, 2009) and that certain skills are harder to acquire after a ‘sensitive period’ (Johnson, 2005). For instance, for most people, learning to speak a second language, especially without an accent, comes with relative ease in early childhood but becomes more difficult later in life (Birdsong, 2001).

MYTH 3: Early screening costs too much for school districts, and there is no time for additional testing.  

There is some truth to this statement. Each school and district must determine the costs of early universal screening. However, many districts already have valid tools for screening the key indicators of dyslexia on hand — the same tools used in second or third grade to assess children who repeatedly fail to learn to read. Reading specialists or special education teachers already may be trained to administer these assessments.

Early assessment could be conducted prior to the start of kindergarten (e.g., in combination with some pre-kindergarten events that already occur), at daycare centers, preschools, or even in collaboration with pediatricians’ offices at the 4- or 5-year-old well-visits. This may add some personnel costs, but it would reduce screening hours and associated costs later in the school year and beyond.

Additional resources are needed for the interpretation and dissemination of the screenings and their results. Various companies now offer the scoring of standardized tests with turnarounds as fast as two weeks, and several online screening tools currently under development aim to reduce both labor and early screening costs.

Yes, early screenings entail significant costs, but given the costs associated with remediation and the treatment of accompanying psychological and medical problems (e.g., depression, anxiety, and psychosomatic conditions related to academic stress), the benefits of early screening outweigh the costs.

It is important to note that the re-allocation of resources for early identification/intervention should not negatively impact intervention efforts in later grades. More specifically, there will be students in older grades who need intervention, and funds used for early intervention should not be taken from the funds currently allocated for older students. If early screening and early intervention achieve expected goals, eventually there should be fewer older students who need that intense intervention. In the interim, those who missed the early screening and intervention still exist. Also, once early screening and early intervention become routine and effective (even with a 50% to 90% success rate), there will be some older students who continue to need support.

There is ample current research in early screening of reading risk that has consistently shown that early, developmentally appropriate measures of phonological awareness, rapid naming, oral listening comprehension, verbal working memory and letter knowledge have solid predictive validity for future reading success or failure.  However, there are additional, important factors in evaluating a young child’s risk for reading difficulty.

Perhaps the earliest indicator of risk for reading failure is a family history of reading difficulties (Catts, 2017). Research shows that approximately 40% to 60% of children with a single parent or a sibling with reading disability will have reading problems themselves (Gilger, Hanebuth, Smith & Pennington, 1996; Scarborough, 1990; Snowling, Gallagher, & Frith, 2003). Studies also show that family risk for reading difficulty, including dyslexia, often experience problems in the development of oral language. A recent study reported that nearly 30% of preschool children with family risk for dyslexia met the criteria for having a specific language impairment (Nash, Hulme, Gooch, & Snowling, 2013).

Since research has shown that early deficits in the development of language are often associated with subsequent difficulties in learning to read, early screening of reading risk should include family history and a review of the child’s developmental history. For example, one of the earliest indicators of problems in oral language and, in some cases, subsequent reading difficulties is failure to begin talking at the appropriate developmental stage. Follow-up investigations have shown that children who were late talkers are generally less skilled than typical children in reading and spelling throughout the school years (Lyytinen et al., 2005; Preston et al., 2010; Rescorla, 2002). Jonathan Preston and colleagues in 2010 also reported that these children were approximately four times more likely to be diagnosed with a reading disability than were children who were not late talkers.

In recent years, important advances have been made in the early identification of risk for reading difficulties such as dyslexia. Educators of young children no longer have to wait for reading problems to develop before the underlying deficits can be identified and addressed. This important work shows that family history of reading difficulties and/or the presence of early developmental language problems often foretell later reading difficulties. When these factors are considered along with the results of early universal screening of predictive skills of reading success and failure, evidence-based interventions can be deployed for those determined to be at risk. Research demonstrates that children who are at risk for dyslexia have better outcomes when identified early and provided with appropriate interventions (Wanzek and Vaughn, 2007).