[Age at diagnosis of Autism Spectrum Disorder depending on ethno-cultural background or migratory status: A systematic literature review].

introductionThe early identification and access to health care of toddlers with autism spectrum disorder (ASD) - or at risk of developing it - is a crucial public health issue, as care and intervention may be more effective in younger children in order to improve their development and prognosis. However, there are still disparities in identification and health care access for children with ASD despite better screening methods. Given that misdiagnosis and delayed diagnosis are often due to the cultural gap between clinician and patient in some psychiatric disorders such as depression or schizophrenia, we examined this question concerning ASD and wondered to what extent ethno-cultural or migratory status might have an impact on the age at which a child is diagnosed. The only published review looking for independent factors influencing age of diagnosis concludes that the factors that have been proved to play a role are: socioeconomic status; symptom severity; level of parental concern, and family interactions with the health and education systems prior to diagnosis. The impact of ethno-cultural or migratory status is less clear. And yet, all these factors may be interconnected: migrants have on average a lower socioeconomic status, minorities don't have the same access to health care, and cultural background can have an influence on what is expected of a child's development and health. In order to try and clarify this issue and to analyze the way in which the international literature approaches the subject, we carried out a systematic review.

methodSix databases were interrogated: Pubmed, Embase, Psychinfo, WebOfScience, Cochrane and Cinahl using the key words "ASD", "pervasive developmental disorder", "diagnosis", "age", "migrant", "ethnicity", "cross cultural". We narrowed neither the period of time not selected the articles by their method, as our objective was to collect the entirety of the articles written on the subject. We completed this review by including the pertinent references made in the articles.

resultsTwenty articles were included, all epidemiological and observational, about children diagnosed in specialized centers. Published between 2002 and 2019, they cover a 20-year research period, between 1992 and 2016. The methods are disparate: the diagnosis criteria used are from DSM IV, IV TR and ICD; data originate from medical records, phone or internet surveys, and Medicaid healthcare claims. Comparison of the age at diagnosis is the principal objective for only thirteen studies; statistical data analyses vary, especially concerning adjustments. Seventy-five percent of the articles originate from North America where the compared populations are defined by ethnic and racial categories that are not used in some other countries, notably in Europe. Only five explore the link between migratory status and age at diagnosis. The research results concerning the impact of ethnicity are contradictory, while those concerning migratory status seem to indicate that migrant children are likely to be diagnosed later. But the articles and their methods being too heterogeneous, it was difficult to make a meta-analysis and impossible to reach a scientific conclusion.

conclusionNevertheless, this review highlights the existence of a lot of confounding factors and raises many issues. It shows that the United States produces most of the studies whose conclusions cannot be generalized because of the particular history and organization of this country. In Europe, where belonging to minority groups is thought to be through migratory status, studies are rare. There is an urgent need for new research in order to clarify the connection between migratory status and socioeconomic factors, to precisely define the independent variables influencing diagnosis -such as access to healthcare- and finally to explore the possibility of different symptomatic expressions depending on cultural backgrounds. This review falls within studies currently carried out by the psychiatric service at Avicenne hospital in Bobigny, France about ASD in a transcultural context.