Concordia researchers become the first to clinically scrutinise the popular Dyslexia Adult Checklist
The neurobiological and developmental learning disorder dyslexia possibly affects up to 15 per cent of the population, but it remains difficult, time-consuming and expensive to accurately diagnose. Screening tools, especially online checklists, can help individuals self-evaluate risk factors, but few if any have been scientifically validated until now.
In a paper published in the journal Dyslexia, Concordia researchers became the first to show that the Dyslexia Adult Checklist, a free online resource developed by the British Dyslexia Association and among the most widely used dyslexia checklists globally, is both valid and reliable as an indicator of dyslexia. They do recommend, however, lowering the threshold of mild dyslexia from its current level.
“Dyslexia can lead to struggles with education and employment, so having a quick and easy tool that can identify certain issues that require a follow-up clinical assessment is helpful,” says Aaron Johnson, an associate professor in the Department of Psychology and the paper’s supervising author. “So, we were surprised to find out that this had never been clinically validated as being a checklist that actually captures dyslexia.”
Aaron Johnson: “We want the tools we use to think about neurodivergence to actually be sensitive to the issues they are supposed to capture.”
Lowering the cut-off score
The researchers recruited 400 participants for their study, split evenly between those who self-identified as having dyslexia and an equal number of those who did not, who completed the questionnaire either online or with pen and paper.
Created in 2011 by Ian Smythe and John Everatt, the checklist is comprised of 15 questions that are used to assess aspects of literacy, language and organization. The following are some examples: “Do you confuse words like ‘cat’ and ‘cot’?”, “Do you lose your place or miss out on lines when reading?” and “How easy do you find it to sound out words like e-le-phant?”
Respondents answer questions using a four-point Likert scale, with certain questions assigned higher weight for the total score. A score of 45 or above indicates the respondent reports symptoms consistent with mild dyslexia and a score of 60 or higher with moderate or severe dyslexia.
Statistical analyses revealed that the checklist proved to be both accurate and reliable. Those who identified as having dyslexia obtained significantly higher total scores than individuals who did not.
“Our results are also interesting because the creators of the checklist provided no evidence why a score of 45 should be the cutoff score for probable dyslexia,” Johnson says.
“We suggest a new cutoff score of 40. It’s a small change, but it seems to be better at capturing actual cases of dyslexia.”
A first step toward treatment
Johnson says that validating the checklist can help both individuals and medical practitioners assess whether a thorough examination for dyslexia is required, which can take months and cost thousands of dollars. Medically approved interventions can lead to speedier access to resources that can assist them in their education or work and reduce the impact dyslexia has on their lives.
“This paper exemplifies the scientist-practitioners’ attitude: we saw a gap and filled it,” says PhD student and lead author Zoey Stark. “Dyslexia is a life-long learning disability, and while it is well studied in children, there is not much research that has looked at the impact on adults.”
Johnson emphasizes the importance of validating the checklist: “We want the tools we use to think about neurodivergence to actually be sensitive to the issues they are supposed to capture,” he concludes. “We hope that people will now feel more confident using it and that this will hopefully lead them to seek out additional support associated with their dyslexia.”
PhD candidate Karine Elalouf, Vanessa Soldano, BSc 21, and former Concordia postdoctoral fellow Léon Franzen, now at the University of Lübeck, contributed research.
This study was supported by the Social Sciences and Humanities Research Council of Canada (SSHRC) and the Fonds de recherche du Québec – Société et culture (FRQSC).
Read the cited paper: “Validation and Reliability of the Dyslexia Adult Checklist in Screening for Dyslexia.”
