Very Early Phonological and Language Skills: Estimating Individual Risk of Reading Disability

Background: Analyses from the Jyvaskyla Longitudinal Study of Dyslexia project show that the key childhood predictors (phonological awareness, short-term memory, rapid naming, expressive vocabulary, pseudoword repetition, and letter naming) of dyslexia differentiate the group with reading disability (n = 46) and the group without reading problems (n = 152) at the end of the 2nd grade. These measures were employed at the ages of 3.5, 4.5 and 5.5 years and information regarding the familial risk of dyslexia was used to find the most sensitive indices of an individual child's risk for reading disability. Methods: Age-specific and across-age logistic regression models were constructed to produce the risk indices. The predictive ability of the risk indices was explored using the ROC (receiver operating curve) plot. Information from the logistic models was further utilised in illustrating the risk with probability curve presentations. Results: The logistic regression models with "familial risk, letter knowledge, phonological awareness" and "RAN" provided a prediction probability above 0.80 (area under ROC). Conclusions: The models including "familial risk status" and the "three above-mentioned measures" offer a rough screening procedure for estimating an individual child's risk for reading disability at the age of 3.5 years. "Probability curves" are presented as a method of illustrating the risk.