Prevalence and cumulative incidence of autism spectrum disorders and the patterns of co-occurring neurodevelopmental disorders in a total population sample of 5-year-old children.

BACKGROUNDS: Whether there is a true increase in autism spectrum disorder (ASD) frequency or not remains unclear. Additionally, the rates of co-existing neurodevelopmental disorders (NDD) in a total population sample has not been fully examined before. Therefore, using a total population sample in Japan, we aimed to estimate the prevalence and cumulative incidence of autism spectrum disorder (ASD) annually, to determine whether there is a true increase in ASD prevalence by estimating the cumulative incidence of ASD annually, and to examine the rates of co-existing neurodevelopmental disorders (NDD). METHOD: In this cross-sectional sequential design study, all 5-year-old children in the catchment area underwent the screening annually from the year 2013-2016. Screen-positive children were invited to participate in a comprehensive assessment, including child and parent interview, behavioral observation, and cognitive and motor function testing. All cases were reviewed by a multidisciplinary research team. RESULTS: Caregivers of 3954 children returned the screening, among which 559 children underwent the assessment with 87 children receiving an ASD diagnosis. Adjusted ASD prevalence was 3.22% (95% confidence interval (CI) 2.66-3.76%). The male to female ratio of the crude prevalence was 2.2:1. The cumulative incidence of ASD up to 5 years of age for the total study years was 1.31% (95% CI 1.00-1.62%). A generalized linear model revealed no significant linear trends in 5-year cumulative incidence over the study years. Only 11.5% of children had ASD alone; the remaining 88.5% were found to have at least one co-existing NDD. LIMITATIONS: Modest sample size for a total population study. CONCLUSIONS: Our findings demonstrate the stability of the 5-year cumulative incidence of ASD, implying no true rise in ASD incident cases over the 4-year study period in the study catchment area. High rates of co-existing NDDs reflect the importance of investigating broad developmental challenges in children with ASD.

Correction: Adaptation of the Autism Spectrum Screening Questionnaire (ASSQ) to preschool children.

[This corrects the article DOI: 10.1371/journal.pone.0199590.].

Adaptation of the Autism Spectrum Screening Questionnaire (ASSQ) to preschool children.

The Autism Spectrum Screening Questionnaire (ASSQ) is equipped with good properties for screening the broader phenotype of autistic traits, but it is standardized for a limited age range-from 7 to 16 years. To contribute to the early detection of Autism Spectrum Disorder (ASD), particularly in high functioning children with ASD, likely to cause maladjustments during school age, the present study examined psychometric properties to apply the ASSQ to a younger age. We tested parents' ASSQ ratings for preschool children in clinical (N = 154, average age 60.77 months, range 55-72 months) and community settings (N = 1390, average age 60.53 months, range 57-68 months) in Japan. The results showed, just as in school-aged children, the ASSQ had reliability and validity as a screening instrument for preschool children in community settings. A cut-off of 7 with sensitivity of 0.93 and specificity of 0.84 is recommended for community screening. Still, based on the current study with a clinical group, an optimal cut-off score with high sensitivity and high specificity for parents' ASSQ ratings could not be established. The clinicians should be reminded that the ASSQ is a screening instrument, not a diagnosing instrument. Also, this result suggest multi-faceted evaluation is necessary in clinical settings, for example, the addition of teachers' ratings.

Coordination difficulties in preschool-aged children are associated with maternal parenting stress: A community-based cross-sectional study.

BACKGROUND: Although coordination difficulties are sometimes observed even in children in the general population, no empirical studies have examined the impact of these difficulties on parenting stress. AIMS: The aim of this study was to elucidate the relationship between coordination difficulties and parenting stress in a community-based sample of preschool-aged children and their mothers. METHODS: The study included 1691 families. Mothers with 4- or 5-year-old children completed questionnaires about parenting stress and children's coordination difficulties, as well as traits associated with attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). RESULTS: The results of hierarchical multiple regression analyses showed that coordination difficulties, and ADHD and ASD traits were each independent predictors of parenting stress. Among the significant predictive factors, impaired general coordination, as well as hyperactivity-impulsivity, showed a strong impact on parenting stress. In addition, a gender difference was observed in the manner in which coordination difficulties influenced parenting stress. CONCLUSIONS: Coordination difficulties in preschool-aged children in the general population increased maternal parenting stress (as did ADHD and ASD traits). This highlights the need to provide support for mothers who have children with coordination difficulties, even when there is no clinical diagnosis.

Prevalence of sleep problems in Japanese preschoolers in a medium-sized city: Community-based survey using the Children's Sleep Habits Questionnaire.

Although the mean score of the Children's Sleep Habits Questionnaire (CSHQ) differs between countries, there are no normative data for the CSHQ of Japanese preschoolers based on a community sample. The aims of this study were therefore to present normative data for the CSHQ and determine the prevalence and characteristics of sleep problems in Japanese preschoolers. Parents or the primary caregiver of 482 preschoolers aged 4-5 years completed the CSHQ and the Strength and Difficulties Questionnaire. Approximately 80% of preschoolers scored above the cut-off for sleep disturbance on the CSHQ. In addition, co-sleeping was prevalent in Japanese preschoolers but the habit of co-sleeping contributed little to behavioral and emotional problems. Sleep problems appear to be prevalent in Japanese preschoolers based on the CSHQ, and could be associated with the Japanese sleep habit of co-sleeping.