Is season of birth related to developmental dyslexia?

Reading and spelling disorders in a school-based population screening in Sicily (Italy)

This research was carried out according to the Italian Consensus Conference on Specific Learning Disability guidelines for screening initiatives. It describes a three-year screening project involving 2.469 students, aged 8-15 years, from various classes of primary, lower and upper secondary schools of Sicily. Students were assessed for reading and spelling skills. Overall, 4.9% met the risk criteria for suspected reading disorder, 6.1% for spelling disorder, while 8.5% for both conditions. Results showed that out of 932 pupils in the primary school, 4.6% met the risk criteria for reading disorder and 6.5% for spelling disorder; out of 855 pupils of the lower secondary school, 5.3% for reading disorder and 5.5% for spelling disorder; out of 652 pupils of the upper secondary school, 4.9% for reading disorder and 6.1% for spelling disorder. No significant difference in the prevalence of students at risk of reading disorder or spelling disorder, within the three grade-levels over 3 years, was found. At project conclusion further clinical investigation to verify the screening results on student sub-sample (57%) was carried out. The percentage of students with SLD was equal to 3.15%, in the primary school, 3.76% in the lower secondary school and 2.51%, in the upper secondary school.

The assignment and distribution of the dyslexia label: Using the UK Millennium Cohort Study to investigate the socio-demographic predictors of the dyslexia label in England and Wales

The prevalence of dyslexia identification has increased significantly over the last two decades. Yet there is debate over whether there are distinct biological and cognitive differences between those with literacy difficulties and the subgroup of people identified as dyslexic. This is the first paper that provides evidence for this ongoing debate by investigating the socio-demographic factors, outside biology and cognition, that predict whether a child is identified as dyslexic in the UK. Using secondary data from the UK’s Millennium Cohort Study, this paper examines the socio-demographic factors that predict whether a child’s teacher identifies them as dyslexic at age 11. Gender, season of birth, socio-economic class and parental income are found to be significant predictors of the dyslexia label. Therefore, factors seemingly unrelated to the clinical aspects of dyslexia influence whether a child is identified as dyslexic in England and Wales. This suggests that label may not be evenly distributed across a population; furthermore, it may also indicate that resources for support may not be fairly allocated. The findings further support the argument that a ‘dyslexic sub-group’ within poor readers is created due to the impact of environmental factors. The results from this national-scale study thus questions the reliability, validity and moral integrity of the allocation of the dyslexia label across current education systems in the UK.

The impact of the dyslexia label on academic outlook and aspirations: An analysis using propensity score matching

BACKGROUND

There is current academic debate over the reliability of the dyslexia label. However, this argument does not consider the impact of the dyslexia label on an individual's academic outlook and aspirations.

AIMS

Using data from the Millennium Cohort Study, this paper aims to objectively explore the impact of the dyslexia label on academic outlook and aspirations.

METHODS

Propensity score matching was used to compare children with dyslexia with a non-dyslexic group matched on ability, socioeconomic class, parent education, income, country, gender, and age in year group.

RESULTS

The results show that those labelled with dyslexia hold lower beliefs about their ability in English and Maths than their matched peers without this label. The children labelled with dyslexia were also significantly less likely to say that they would go to university. Furthermore, teachers and parents held lower aspirations for children labelled with dyslexia. As the children were matched, the results show that dyslexic children, their teachers and parents hold lower expectations of the child's academic ability while holding higher expectations of those with matched characteristics who do not have the dyslexia label.

CONCLUSIONS

The paper concludes that caution is needed when labelling with dyslexia and that further research is needed in order establish whether labelling with dyslexia is beneficial in the current system.

Birth month is associated with learning capacity in childhood in Northeast China

It is difficult to evaluate long-term ventilation and indoor-outdoor temperature variation on-site in the birth residence so as to investigate their associations with learning capacity from childhood through adolescence. Here, we conducted a questionnaire-based retrospective cohort study in ten schools from two northeast China cities with warm summers and severe cold winters when residences had very low air exchange rates. Scores for Chinese, Mathematics, and English in the final exams of the summer semester in June 2018 were collected to evaluate learning capacity. We surveyed 6238 students aged 14.7 (SD: 2.1) years old. Using the 2nd quarter (April-May-June) birth as reference, 4th quarter (October-November-December) birth consistently was significantly associated with lower scores in Chinese in bivariate (β, 95%CI: -3.2, -4.3 to -2.0) and multivariate (-1.8, -2.4 to -0.8) linear regression analyses. Stratified sub-analyses showed significant associations for male (-2.4, -3.7 to -1.1), urban (-2.4, -3.4 to -1.4), and primary students (-2.9, -4.5 to -1.4). Since household ventilation and indoor-outdoor temperature variation had great differences between the 2nd and 4th quarter of year, our results suggest that these two factors in the birth residence could be associated with learning capacity in childhood, especially for male and primary students in northeast China.

Differential Identification of Females and Males with Reading Difficulties: A Meta-Analysis

Males are more likely than females to be identified as having reading difficulties, but it is unclear if this is a result of sample ascertainment or identification bias. The purpose of this meta-analysis was to determine the magnitude of gender differences in reading difficulties using available studies in which researchers investigated this difference and an additional dataset with a representative U.S.

SAMPLE

After conducting a literature search, sixteen studies and a restricted use dataset were included in the present analysis (N = 552,729). A random-effects odds ratio (OR) model indicated that males are 1.83 times more likely than females to have reading difficulties. Moderator analyses revealed that the gender ratio is greater when the identified reading difficulties were more severe. Further, this difference in identification rates across males and females was found without evidence of publication bias. Implications for the identification of students with reading difficulties are discussed.

Frequency of occurrence of specific reading disorder and associated psychiatric comorbidity in a sample of Egyptian primary school students

BACKGROUND

Specific reading disorder (dyslexia) is common in primary school students. Data on prevalence rates in Egypt are needed along with better screening tools to guide future research. We aimed to estimate the frequency of dyslexia in a sample of fourth and fifth graders.

METHOD

A cross-sectional study was conducted in Eastern Cairo through multistage random selection of students from three governmental primary schools. A total of 586 students were recruited. Only 567 students fulfilled the inclusion criteria; they were subjected to screening by Goodenough Draw-a-Man test for intellectual quotient (IQ), the Reading Disability Test of Nasra Gilgil (RDT) to identify dyslexic children, Wechsler Children Intelligence Scale for thorough detection of IQ, and the Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS-PL) to detect psychiatric comorbidity.

RESULTS

The frequency of occurrence of specific reading disorder (dyslexia) was 11.3% among the studied sample of Egyptian primary school students. The gender ratio was nearly 1.3:1 boys to girls. Comorbidity with other psychiatric disorders was found in 57.8% of the sample. Attention deficit hyperactivity disorder (ADHD) was present in 33%, generalized anxiety disorder in 21.6%, and major depressive disorder in 16.2% of patients.

CONCLUSION

Dyslexia was prevalent in fourth and fifth graders. A meaningful presence of ADHD, anxiety, and depressed mood was detected in students. There is a need for better screening and awareness for early intervention and service provision. The cross-sectional design, lack of collateral information, and records precluded inference of casualty. The lack of rural comparator and samples from other governorates limit generalization of results.

Environmental Risk Factors in Han and Uyghur Children with Dyslexia: A Comparative Study

Background

Several studies have been conducted to explore risk factors for dyslexia. However, most studies examining dyslexia have been skewed toward Western countries, and few have considered two nationalities simultaneously. This study focused on differences in dyslexia prevalence and potential environmental risk factors between Han and Uyghur children.

Methods

A cross-sectional study was conducted in Kashgar and Aksu, cities in Xinjiang province, China. A two-stage sampling strategy was used to recruit 2,854 students in grades 3–6 from 5 primary schools in 5 districts; 2,348 valid student questionnaires were included in the analysis. Dyslexia checklists for Chinese and Uyghur children and pupil rating scales were used to identify children with dyslexia. Questions related to the home literacy environment and reading ability were used to evaluate potential environmental risk factors. Single factor analysis and multivariate logistic regression were used to examine prevalence and risk factors for dyslexia.

Results

Dyslexia prevalence differed significantly between Han (3.9%) and Uyghur (7.0%) children (P < 0.05), and the boy-to-girl diagnosis ratio was almost 2:1. Multiple logistic regression analysis showed that ethnic differences in dyslexia prevalence between Han and Uyghur children could have occurred because of factors such as mother’s occupation (P = 0.02, OR = 0.04, 95% CI = 0.01–0.68) and the frequency with which parents told stories (P = 0.00, OR = 4.50, 95% CI = 1.67–12.11).

Conclusions

The prevalence of dyslexia was high in all children, particularly those in the Uyghur group. Environmental factors could have been responsible for some of the differences observed. The results contribute to the early identification and management of dyslexia in children from these two groups and research examining developmental dyslexia and differences in racial genetics.

Automatic and controlled processing and the Broad Autism Phenotype

Research related to verbal fluency in the Broad Autism Phenotype (BAP) is limited and dated, but generally suggests intact abilities in the context of weaknesses in other areas of executive function (Hughes et al., 1999; Wong et al., 2006; Delorme et al., 2007). Controlled processing, the generation of search strategies after initial, automated responses are exhausted (Spat, 2013), has yet to be investigated in the BAP, and may be evidenced in verbal fluency tasks. One hundred twenty-nine participants completed the Delis-Kaplan Executive Function System Verbal Fluency test (D-KEFS; Delis et al., 2001) and the Broad Autism Phenotype Questionnaire (BAPQ; Hurley et al., 2007). The BAP group (n=53) produced significantly fewer total words during the 2nd 15" interval compared to the Non-BAP (n=76) group. Partial correlations indicated similar relations between verbal fluency variables for each group. Regression analyses predicting 2nd 15" interval scores suggested differentiation between controlled and automatic processing skills in both groups. Results suggest adequate automatic processing, but slowed development of controlled processing strategies in the BAP, and provide evidence for similar underlying cognitive constructs for both groups. Controlled processing was predictive of Block Design score for Non-BAP participants, and was predictive of Pragmatic Language score on the BAPQ for BAP participants. These results are similar to past research related to strengths and weaknesses in the BAP, respectively, and suggest that controlled processing strategy use may be required in instances of weak lower-level skills.

Prevalence and associated risk factors of dyslexic children in a middle-sized city of China: a cross-sectional study

Background

There are many discussions about dyslexia based on studies conducted in western countries, and some risk factors to dyslexia, such as gender and home literacy environment, have been widely accepted based on these studies. However, to our knowledge, there are few studies focusing on the risk factors of dyslexia in China. Therefore, the aim of our study was to investigate the prevalence of dyslexia and its potential risk factors.

Methods

A cross-sectional study was conducted in Qianjiang, a city in Hubei province, China. Two stages sampling strategy was applied to randomly selected 5 districts and 9 primary schools in Qianjiang. In total, 6,350 students participated in this study and there were 5,063 valid student questionnaires obtained for the final analyses. Additional questionnaires (such as Dyslexia Checklist for Chinese Children and Pupil Rating Scale) were used to identify dyslexic children. The chi-square test and multivariate logistic regression were employed to reveal the potential risk factors to dyslexia.

Results

Our study revealed that the prevalence of dyslexia was 3.9% in Qianjiang city, which is a middle-sized city in China. Among dyslexic children, the gender ratio (boys to girls) was nearly 3∶1. According to the P-value in the multivariate logistic regression, the gender (P<0.01), mother's education level (P<0.01), and learning habits (P<0.01) (active learning, scheduled reading time) were associated with dyslexia.

Conclusion

The prevalence rate of dyslexic children in middle-sized cities is 3.9%. The potential risk factors of dyslexic children revealed in this study will have a great impact on detecting and treating dyslexic children in China as early as possible, although more studies are still needed to further investigate the risk factors of dyslexic children in China.

Specific language disorders and season of birth: underlying environmental factors or chance findings?

The medical records of 358 children and adolescents with specific language disorders (SLD; 122 girls and 236 boys) seen in rehabilitation centers from Northern and Central Italy were examined to compare season of birth in these cases to those of the Italian population. Exposure was calculated using univariate and multivariate odds ratios (ORs) and 95% confidence intervals (CIs). Compared to the Italian population, patients with SLD had a 1.67 (95% CI [1.35-2.07]) chance of birth in October-December. Independent predictors were younger age at inclusion and being firstborn. Different neurobiological hypotheses can be drawn to explain these findings.

The joint effects of risk status, gender, early literacy and cognitive skills on the presence of dyslexia among a group of high-risk Chinese children

This study sought to examine factors that are predictive of future developmental dyslexia among a group of 5-year-old Chinese children at risk for dyslexia, including 62 children with a sibling who had been previously diagnosed with dyslexia and 52 children who manifested clinical at-risk factors in aspects of language according to testing by paediatricians. The age-5 performances on various literacy and cognitive tasks, gender and group status (familial risk or language delayed) were used to predict developmental dyslexia 2 years later using logistic regression analysis. Results showed that greater risk of dyslexia was related to slower rapid automatized naming, lower scores on morphological awareness, Chinese character recognition and English letter naming, and gender (boys had more risk). Three logistic equations were generated for estimating individual risk of dyslexia. The strongest models were those that included all print-related variables (including speeded number naming, character recognition and letter identification) and gender, with about 70% accuracy or above. Early identification of those Chinese children at risk for dyslexia can facilitate better dyslexia risk management.