Prevalence of Autism Spectrum Disorder in a large Italian catchment area: a school-based population study within the ASDEU project.

AIMS: This study aims to estimate Autism Spectrum Disorders (ASD) prevalence in school-aged children in the province of Pisa (Italy) using the strategy of the ASD in the European Union (ASDEU) project. METHODS: A multistage approach was used to identify cases in a community sample (N = 10 138) of 7-9-year-old children attending elementary schools in Pisa - Italy. First, the number of children with a disability certificate was collected from the Local Health Authority and an ASD diagnosis was verified by the ASDEU team. Second, a Teacher Nomination form (TN) to identify children at risk for ASD was filled in by teachers who joined the study and the Social Communication Questionnaire (SCQ) was filled in by the parents of children identified as positive by the TN; a comprehensive assessment, which included the Autism Diagnostic Observation Schedule-Second Edition, was performed for children with positive TN and SCQ⩾9. RESULTS: A total of 81 children who had a disability certificate also had ASD (prevalence: 0.79%, i.e. 1/126). Specifically, 66 children (57 males and nine females; 62% with intellectual disability -ID-) were certified with ASD, whereas another 15 (11 males and four females; 80% with ID) were recognised as having ASD among those certified with another neurodevelopmental disorder. Considering the population of 4417 (children belonging to schools which agreed to participate in the TN/SCQ procedure) and using only the number of children certified with ASD, the prevalence (38 in 4417) was 0.86%, i.e. one in 116. As far as this population is concerned, the prevalence rises to 1% if we consider the eight new cases (six males and two females; no subject had ID) identified among children with no pre-existing diagnoses and to 1.15%, i.e., one in 87, if probabilistic estimation is used. CONCLUSIONS: This is the first population-based ASD prevalence study conducted in Italy so far and its results indicate a prevalence of ASD in children aged 7-9 years of about one in 87. This finding may help regional, national and international health planners to improve ASD policies for ASD children and their families in the public healthcare system.

Evaluating Sex and Age Differences in ADI-R and ADOS Scores in a Large European Multi-site Sample of Individuals with Autism Spectrum Disorder.

Research on sex-related differences in Autism Spectrum Disorder (ASD) has been impeded by small samples. We pooled 28 datasets from 18 sites across nine European countries to examine sex differences in the ASD phenotype on the ADI-R (376 females, 1763 males) and ADOS (233 females, 1187 males). On the ADI-R, early childhood restricted and repetitive behaviours were lower in females than males, alongside comparable levels of social interaction and communication difficulties in females and males. Current ADI-R and ADOS scores showed no sex differences for ASD severity. There were lower socio-communicative symptoms in older compared to younger individuals. This large European ASD sample adds to the literature on sex and age variations of ASD symptomatology.

Disentangling the initiation from the response in joint attention: an eye-tracking study in toddlers with autism spectrum disorders.

Joint attention (JA), whose deficit is an early risk marker for autism spectrum disorder (ASD), has two dimensions: (1) responding to JA and (2) initiating JA. Eye-tracking technology has largely been used to investigate responding JA, but rarely to study initiating JA especially in young children with ASD. The aim of this study was to describe the differences in the visual patterns of toddlers with ASD and those with typical development (TD) during both responding JA and initiating JA tasks. Eye-tracking technology was used to monitor the gaze of 17 children with ASD and 15 age-matched children with TD during the presentation of short video sequences involving one responding JA and two initiating JA tasks (initiating JA-1 and initiating JA-2). Gaze accuracy, transitions and fixations were analyzed. No differences were found in the responding JA task between children with ASD and those with TD, whereas, in the initiating JA tasks, different patterns of fixation and transitions were shown between the groups. These results suggest that children with ASD and those with TD show different visual patterns when they are expected to initiate joint attention but not when they respond to joint attention. We hypothesized that differences in transitions and fixations are linked to ASD impairments in visual disengagement from face, in global scanning of the scene and in the ability to anticipate object's action.

The CBCL 1.5-5 and the identification of preschoolers with autism in Italy.

AIMS: To study the potential use of child behaviour checklist (CBCL) 1.5-5 scales for the early identification of preschoolers at risk of autism. METHODS: CBCL scores of three groups of preschoolers were compared: (1) an experimental group of 101 preschoolers with autism spectrum disorder (ASD); (2) a control group of 95 preschoolers with other psychiatric disorders (OPD); (3) a control group of 117 preschoolers with typical development (TD). One-way analysis of variance (ANOVA), logistic regression with odds ratio (OR) and receiver operating characteristic (ROC) analyses were performed. RESULTS: ANOVA revealed that ASD and OPD had significantly higher scores in almost all CBCL scales than TD. ASD presented significantly higher scores than OPD on Withdrawn, Attention Problems and Pervasive Developmental Problems (PDP) scales. Logistic regression analysis demonstrated that these same CBCL scales have validity in predicting the presence of an ASD towards both TD and OPD. ROC analysis indicated high sensitivity and specificity for PDP (0.85 and 0.90) and Withdrawn (0.89 and 0.92) scales when ASD is compared to TD. Specificity (0.60 for PDP and 0.65 for Withdrawn) decreases when comparing ASD and OPD CONCLUSIONS: The PDP and Withdrawn scales have a good predictive validity so that they could be proposed as a first-level tool to identify preschoolers at risk of autism in primary care settings. Problems regarding the lower specificity when comparing ASD v. OPD are discussed.