01 NRDC Dyslexia 1-88 update - Texthelp

Developmental dyslexia in adults: a research review
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Appendix 8
Screening for dyslexic adults
‘Methods for diagnosing dyslexia in adults vary and the appropriateness and validity of
many tests is contentious.’ Department for Education and Skills (2002). Dyslexia and
related specific learning difficulties. Accessed at
www.dfes.gov.uk/curriculum_literacy/access/dyslexia on 28 November 2002.
‘One would be hard pressed to find a clear consensus within the dyslexia community
to such fundamental questions as how best dyslexia is diagnosed’ (page 56). Nicolson,
R. I. (2002). The dyslexia ecosystem. Dyslexia, 8, 55–66.
‘The diagnosis of dyslexia is itself a theory, distinguishing reading failure arising
ultimately from internal rather than solely external reasons, but a rather unspecified
one … ’ (page 558). Frith, U. (2001). What framework should we use for understanding
developmental disorders? Developmental Neuropsychology, 20(2), 555–563.
‘The incidence of SDD is either 4% (severe) or 10% (mild) according to estimates by
some organisations, including the British Dyslexia Association … Such estimates of
prevalence are both theoretically and technically contentious’ (page 153). Pumfrey, P.
(2001). Specific Developmental Dyslexia (SDD): ‘Basics to back’ in 2000 and beyond?
In M. Hunter-Carsch (Ed.), Dyslexia: a psychosocial perspective. London: Whurr.
‘Any attempt to determine the prevalence of dyslexia should be treated with caution’
(page 27). Miles, T. R. and Miles, E. (1999). Dyslexia: a hundred years on. (Second
ed.). Buckingham: Open University Press.
‘With a developmental condition such as dyslexia, there is an increased probability of
secondary symptoms arising with increasing age. Given that there can also be
interactive effects, the job of disentangling and understanding the causes and
consequences of a person’s pattern of difficulties is usually very difficult and
sometimes impossible … The more secondary difficulties there are, the harder it
becomes to detect the dyslexia’ (page 68). Rack, J. (1997). Issues in the assessment of
developmental dyslexia in adults: theoretical and applied perspectives. Journal of
Research in Reading, 20(1), 66–76.
‘If there is, for any age and IQ, an uninterrupted gradation from good reading to bad,
then the question of where to draw the line is an entirely arbitrary one. Therefore, to
ask how prevalent dyslexia is in the general population will be as meaningful, and as
meaningless, as asking how prevalent obesity is. The answer will depend entirely on
where the line is drawn’ (page 172). Ellis, A. W. (1985). The cognitive neuropsychology
of developmental (and acquired) dyslexia: a critical survey. Cognitive
Neuropsychology, 2(2), 169–205.
An epidemiological study has three options, broadly speaking, for determining the prevalence
of a disability. It can ask respondents a single question of the kind ‘Do you have X?’ with three
response options: ‘yes’, ‘no’, and ‘I don’t know’. It can employ a screening instrument alone
and infer the prevalence of the condition from the instrument’s known positive predictive