Table 1.
Overview prevalence studies reporting comorbidity rates for learning disorders based on representative samples.
Figure 1.
Prevalence rates (N = 1633) for specific learning disorders: isolated and combined deficits in reading, spelling, and arithmetic skills.
Note: sd = standard deviation; CI = confidence interval; RD = Reading Deficit; SD = Spelling Deficit; AD = Arithmetic Deficit; RSD/SRD = Reading and spelling Deficit; RAD/ARD = Reading and arithmetic Deficit; SAD/ASD = Spelling and Arithmetic Deficit; RSAD/SRAD/ARSD = Reading, spelling and arithmetic Deficit.
Figure 2.
Prevalence rates (N = 1633) for specific learning disorders including cutoff for normal performance.
Note: Between = children who fulfill deficit criteria for the relevant domain (RD, SD or AD), but score between the deficit criterion and the criterion for normal performance on at least one other measure.
Table 2.
Expected and observed number of comorbid cases for the three cutoff criteria.
Table 3.
Gender ratios for isolated and comorbid learning disorders.