Prevalence estimates of neurodevelopmental disorders in Japan: A community sample questionnaire study

Abstract

Aim Prevalence estimates of neurodevelopmental disorders have been calculated by questionnaire surveys scored by a single rater, which introduces inherent rater biases. The present study aimed to estimate the prevalence and comorbidity rates of four neurodevelopmental disorders based on both parent and teacher rating scales. Methods We performed a community sample survey recruiting 3852 children aged 6 to 9 years. Parents and teachers evaluated clinical conditions in children using questionnaire‐style scales. These scales with cut‐off values were used to estimate the prevalence and comorbidity rates of attention deficit hyperactive disorder, autism spectrum disorder, specific learning disorder (or developmental dyslexia), and developmental coordination disorder. Results The prevalence estimates were separately confirmed according to the raters. Some estimates were higher than those in previous studies conducted in other countries. We also found a large disagreement between the parent and teacher rating scores. Moreover, the degree of agreement between two raters varied depending on the severity of the child's clinical condition. Conclusion These estimates are the first findings based on evaluating children by two different raters. The prevalence and comorbidity estimates are informative for researchers and clinicians of pediatric neurology. The disagreements between two different raters raise questions about previous estimates of neurodevelopmental disorders.

A Comprehensive Meta-analysis of the Prevalence of Autism Spectrum Disorders

“…The study found that the prevalence rate of autism based on clinical diagnostic criteria in China is 59.8 per 10,000, which is lower than that of 820 per 10,000 abroad and also lower than that of other countries in the world. This finding is similar to that of Chiarotti [9], the median prevalence rate of autism in Europe is 61.9 per 10,000 [10], the prevalence rate of autism in the USA is 110 per 10,000 [11], 264 per 10,000 people in South Korea have autism [12], and 181 autism per 10,000 people in Japan [13].…”

Epidemiology of Autism Spectrum Disorders: A Review of Worldwide Prevalence Estimates Since 2014

“…In Japan, a community sample survey was performed to estimate prevalence of neurodevelopmental disorders (NDD) and their co-occurrence in children aged 6-9 years, using questionnaires administered to parents and teachers [32]. The estimated prevalence of ASD, alone or in co-occurrence with other NDD, was 19.0/1000 based on parent's reports, and rose to 93.0/1000 based on teacher's reports.…”

“…Prevalence estimates show a very large variability across countries, ranging from very low values estimated in Iran, 2012 (0.63/1000) and Bangladesh, 2018 (0.76/1000), to low values estimated in India, 2017 (1.53/1000), China, 2011 (1.77/1000), India, 2017 (2.19/1000), China, 2014 (2.75/1000), Nepal, 2018 (3.42/1000), Israeli, 2013 (4.80/1000). On the contrary, large values were estimated in Bangladesh, 2009 (8.42/1000) and Sri Lanka, 2009 (10.7/1000), and very large values in Lebanon, 2016 (15.3/1000) and South Korea, 2011 (26.4/1000).The Qiu's review did not include some recent studies performed in China[29][30][31], in Japan[32], and in India[33]. In China,Yang et al (2015) [31] performed ASD assessment in 2014 in toddlers (3.8 to 4.8 years of age) who attended mainstream kindergarten in Shenzhen, estimating ASD prevalence at 26.2/1000 Sun et al (2015).…”

Development and Preliminary Validation of the Couples’ Stigma Scale to Assess Self-Stigma among the Partners of Persons with Autism Spectrum Disorder in Japan

“…A recent study using population-based survey data reported the estimated prevalence of ASD in Japan as being 1.68% [2]. Although prevalence estimates vary somewhat between studies, the rate in Japan is reportedly higher than in some other countries that have been studied [3]. Previously, individuals with ASD were considered awkward in interpersonal relationships, and it was assumed that adults with ASD rarely married [4,5].…”