ASD Prevalence Study Across Europe: Developing a School-Based Teacher Nomination and Screening Approach
In the wake of dramatic increases in ASD prevalence in recent decades, parent organizations are advocating for better services in many national governments across the European Union (EU). It is expected that over the next few years, the increase in political pressure will oblige governments to respond appropriately to this demand. Currently, however, there is no system for measuring ASD prevalence in the EU to provide baseline public health information. An important feature of such a baseline system would be a standardized method applicable across EU sites that would yield comparable prevalence rates across geographic areas.
The main objective of the presentation is to describe the strategy of the Autism Spectrum Disorder in the European Union (ASDEU) project to estimate the prevalence of ASD in school-aged children across Europe. The focus is on the novel field study methods and aims to be a reflexion on what we have learned regarding standardization of study methods across sites, what has worked well and what could be done differently in the future.
A cross-sectional field study was implemented in the ASDEU project to ascertain ASD cases in 8 European countries: Austria, Bulgaria, Ireland, Italy, Poland, Portugal, Romania, Spain. The field study is based on a 3-stage screening strategy in primary schools including 1) Teacher Nomination (TN); 2) screening of nominated children using the Social Communication Questionnaire (SCQ); 3) clinical evaluation of SCQ positive children using ADOS and psychometric measures. A target population of 200000 children aged 7-9 years residing within the selected areas during 2016 is expected to be screened (8,000-10,000 per country).
The main challenges in the cross-sectional field study were common across sites and related to the adjustment of the study timeframe to school calendar years, the harmonization of screening methods to different educational/health systems and country-specific authorization requirements. Piloting of the TN method in schools known to have ASD children indicated that the number and type of issues signalled by teachers for nominated children are different for children with ASD or with other neurodevelopmental problems. A total of over 13,000 school children have already been screened in 5 countries, with 2,035 children (approximately 15%) nominated by teachers. The TN method, after translation and adaptation in 8 countries, was generally well received by teachers. The overall school participation rate was 92.5% in 5 sites, ranging from 42.5% to 100%, indicating that some countries require additional efforts to promote the study in schools. Initial findings regarding SCQ and clinical assessments across sites will be presented.
ASDEU is the first study to estimate ASD prevalence across European countries using a common methodology. Analysis of early results indicates the field study is feasible and challenges related to cultural and educational systems diversity can be overcome. This method will be compared with population-registry screening approaches in Iceland, Finland, France and Denmark. The final ASD prevalence estimated across Europe will be fundamental to establish an evidence-based, EU-wide response to the growing societal needs of individuals with autism.