Register-based cumulative prevalence of Autism Spectrum Disorders during childhood and adolescence in Central Italy

Authors

DOI:

https://doi.org/10.2427/13226

Abstract

Background: Studies have evaluated the prevalence of Autism Spectrum Disorders (ASD), focusing on different ages during childhood and adolescence. How cumulative prevalence increases before adulthood remains unclear. 

Methods: We used data from the Autism Register of the Regional Reference Centre for Autism in L’Aquila, Central Italy, to retrieve information on individuals born in 2001–2012 with any of the inclusion diagnoses of ASD (DSM criteria) for the period 2001 to 2018. Cumulative prevalence on L’Aquila district population data was calculated as percentages for three-year age strata. 

Results: All prevalence data were estimated at December 31st, 2018. The overall crude prevalence was 0.95% (352 cases over 36938 population). Cumulative prevalence was 1.19% among those born in 2001-2003 (15 to 17 years of follow up), 1.15% among those born in 2004-2006 (12 to 14 years of follow up), 1.04% among those born in 2007-2009 (9 to 11 years of follow up), 0.80% among those born in 2010-2012 (6 to 8 years of follow up), and 0.57% among those born in 2013-2015 (3 to 5 years of follow up). The proportion of ASD diagnoses until the age of 5 years, compared to the group diagnosed 6 to 8 years of age, showed a significant increasing trend over calendar time (53.6% for those born in 2001-2003, to 77.0% for those born in 2010-2012). 

Conclusions: Cumulative prevalence by time period provides a better understanding of ASD occurrence than a point prevalence. We did not find any difference in frequency of diagnosis comparing age strata and year of birth, suggesting that frequencies of ASD diagnosis remained roughly constant from 2001 to 2015. Results show that cumulative prevalence of autism diagnosis does not substantially change over time; instead, diagnosis of ASD is more likely at earliest ages over time, although new cases of ASD are also detected at later ages. 

Author Biographies

Marco Valenti, University of L’Aquila

Department of Applied Clinical Sciences and Biotechnology, Section of Clinical Epidemiology & Autism Research Laboratory, University of L’Aquila, Italy

Regional Reference Centre for Autism (Centro di Riferimento Regionale per l’Autismo), Abruzzo Region Local Health Authority 1 (ASL 1), L’Aquila, Italy

Roberto Vagnetti, University of L’Aquila, Italy

Department of Applied Clinical Sciences and Biotechnology, Section of Clinical Epidemiology & Autism Research Laboratory, University of L’Aquila, Italy

Francesco Masedu, University of L’Aquila

Department of Applied Clinical Sciences and Biotechnology, Section of Clinical Epidemiology & Autism Research Laboratory, University of L’Aquila, Italy

Maria Chiara Pino, University of L’Aquila

Department of Applied Clinical Sciences and Biotechnology, Section of Clinical Epidemiology & Autism Research Laboratory, University of L’Aquila, Italy

Regional Reference Centre for Autism (Centro di Riferimento Regionale per l’Autismo), Abruzzo Region Local Health Authority 1 (ASL 1), L’Aquila, Italy

Alessandro Rossi, University of L’Aquila

Department of Applied Clinical Sciences and Biotechnology, Section of Neuroscience, University of L’Aquila

Department of Mental Health, Abruzzo Region Local Health Authority 1 (ASL 1), L’Aquila, Italy

Maria Luisa Scattoni, Higher Institute of Health, Rome, Italy

National Observatory on Autism, Higher Institute of Health (Istituto Superiore di Sanità), Rome, Italy

Monica Mazza, University of L’Aquila

Department of Applied Clinical Sciences and Biotechnology, Section of Clinical Epidemiology & Autism Research Laboratory, University of L’Aquila, Italy

Regional Reference Centre for Autism (Centro di Riferimento Regionale per l’Autismo), Abruzzo Region Local Health Authority 1 (ASL 1), L’Aquila, Italy

EAGLE GROUP

The EAGLE (Epidemiology of Autism Gauge L’Aquila Équipe) members: Chiara Di Giovanni, Margherita Attanasio, Angela Filocamo, Ilenia Le Donne, Martina Siracusano

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Published

2022-01-27

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Original articles