Autism and Intellectual Disability Are Differentially Related to Sociodemographic Background at Birth

Background: Research findings investigating the sociodemographics of autism spectrum disorder (ASD) have been inconsistent and rarely considered the presence of intellectual disability (ID). Methods: We used population data on Western Australian singletons born from 1984 to 1999 (n = 398,353) to ex...

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Main Authors: Leonard, H., Glasson, E., Nassar, N., Whitehouse, A., Bebbington, A., Bourke, J., Jacoby, P., Dixon, G., Malacova, Eva, Bower, C., Stanley, F.
Format: Journal Article
Published: Public Library of Science (PLoS) 2011
Online Access:http://hdl.handle.net/20.500.11937/47573
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author Leonard, H.
Glasson, E.
Nassar, N.
Whitehouse, A.
Bebbington, A.
Bourke, J.
Jacoby, P.
Dixon, G.
Malacova, Eva
Bower, C.
Stanley, F.
author_facet Leonard, H.
Glasson, E.
Nassar, N.
Whitehouse, A.
Bebbington, A.
Bourke, J.
Jacoby, P.
Dixon, G.
Malacova, Eva
Bower, C.
Stanley, F.
author_sort Leonard, H.
building Curtin Institutional Repository
collection Online Access
description Background: Research findings investigating the sociodemographics of autism spectrum disorder (ASD) have been inconsistent and rarely considered the presence of intellectual disability (ID). Methods: We used population data on Western Australian singletons born from 1984 to 1999 (n = 398,353) to examine the sociodemographic characteristics of children diagnosed with ASD with or without ID, or ID without ASD compared with non-affected children. Results: The profiles for the four categories examined, mild-moderate ID, severe ID, ASD without ID and ASD with ID varied considerably and we often identified a gradient effect where the risk factors for mild-moderate ID and ASD without ID were at opposite extremes while those for ASD with ID were intermediary. This was demonstrated clearly with increased odds of ASD without ID amongst older mothers aged 35 years and over (odds ratio (OR) = 1.69 [CI: 1.18, 2.43]), first born infants (OR = 2.78; [CI: 1.67, 4.54]), male infants (OR = 6.57 [CI: 4.87, 8.87]) and increasing socioeconomic advantage. In contrast, mild-moderate ID was associated with younger mothers aged less than 20 years (OR = 1.88 [CI: 1.57, 2.25]), paternal age greater than 40 years (OR = 1.59 [CI: 1.36, 1.86]), Australian-born and Aboriginal mothers (OR = 1.60 [CI: 1.41, 1.82]), increasing birth order and increasing social disadvantage (OR = 2.56 [CI: 2.27, 2.97]). Mothers of infants residing in regional or remote areas had consistently lower risk of ASD or ID and may be linked to reduced access to services or underascertainment rather than a protective effect of location. Conclusions: The different risk profiles observed between groups may be related to aetiological differences or ascertainment factors or both. Untangling these pathways is challenging but an urgent public health priority in view of the supposed autism epidemic.
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spelling curtin-20.500.11937-475732017-09-13T14:13:44Z Autism and Intellectual Disability Are Differentially Related to Sociodemographic Background at Birth Leonard, H. Glasson, E. Nassar, N. Whitehouse, A. Bebbington, A. Bourke, J. Jacoby, P. Dixon, G. Malacova, Eva Bower, C. Stanley, F. Background: Research findings investigating the sociodemographics of autism spectrum disorder (ASD) have been inconsistent and rarely considered the presence of intellectual disability (ID). Methods: We used population data on Western Australian singletons born from 1984 to 1999 (n = 398,353) to examine the sociodemographic characteristics of children diagnosed with ASD with or without ID, or ID without ASD compared with non-affected children. Results: The profiles for the four categories examined, mild-moderate ID, severe ID, ASD without ID and ASD with ID varied considerably and we often identified a gradient effect where the risk factors for mild-moderate ID and ASD without ID were at opposite extremes while those for ASD with ID were intermediary. This was demonstrated clearly with increased odds of ASD without ID amongst older mothers aged 35 years and over (odds ratio (OR) = 1.69 [CI: 1.18, 2.43]), first born infants (OR = 2.78; [CI: 1.67, 4.54]), male infants (OR = 6.57 [CI: 4.87, 8.87]) and increasing socioeconomic advantage. In contrast, mild-moderate ID was associated with younger mothers aged less than 20 years (OR = 1.88 [CI: 1.57, 2.25]), paternal age greater than 40 years (OR = 1.59 [CI: 1.36, 1.86]), Australian-born and Aboriginal mothers (OR = 1.60 [CI: 1.41, 1.82]), increasing birth order and increasing social disadvantage (OR = 2.56 [CI: 2.27, 2.97]). Mothers of infants residing in regional or remote areas had consistently lower risk of ASD or ID and may be linked to reduced access to services or underascertainment rather than a protective effect of location. Conclusions: The different risk profiles observed between groups may be related to aetiological differences or ascertainment factors or both. Untangling these pathways is challenging but an urgent public health priority in view of the supposed autism epidemic. 2011 Journal Article http://hdl.handle.net/20.500.11937/47573 10.1371/journal.pone.0017875 Public Library of Science (PLoS) fulltext
spellingShingle Leonard, H.
Glasson, E.
Nassar, N.
Whitehouse, A.
Bebbington, A.
Bourke, J.
Jacoby, P.
Dixon, G.
Malacova, Eva
Bower, C.
Stanley, F.
Autism and Intellectual Disability Are Differentially Related to Sociodemographic Background at Birth
title Autism and Intellectual Disability Are Differentially Related to Sociodemographic Background at Birth
title_full Autism and Intellectual Disability Are Differentially Related to Sociodemographic Background at Birth
title_fullStr Autism and Intellectual Disability Are Differentially Related to Sociodemographic Background at Birth
title_full_unstemmed Autism and Intellectual Disability Are Differentially Related to Sociodemographic Background at Birth
title_short Autism and Intellectual Disability Are Differentially Related to Sociodemographic Background at Birth
title_sort autism and intellectual disability are differentially related to sociodemographic background at birth
url http://hdl.handle.net/20.500.11937/47573