Autism and Socioeconomic Status-An Immune Link?

Association Between Socioeconomic Status and Prevalence of Hypersensitivity Diseases and Autism: A Nationwide Study of Children

OBJECTIVE

Prior research suggests that children with a low socioeconomic status (SES) background are at an increased risk for special healthcare needs. Conversely, for hypersensitivity-related diseases, many studies reported a lower risk among children with lower SES according to the hygiene hypothesis. We aimed to evaluate the association between SES and several hypersensitivity diseases and autism in a representative American sample.

METHODS

We used data from the 2016, 2017 and 2018 US National Survey of Children's Health. A total of 102,341 children aged 0-17 years were included. The dependent variables were doctor-diagnosed allergies, arthritis, asthma, diabetes, and autism. The main SES indicators were family poverty levels, highest education of the reported adults and difficulty in family income. Our analysis used logistic regression that accounted for the survey sampling design.

RESULTS

The sample had a mean age of 9.4 ± 5.3 years. The weighted prevalence for allergies was 24.4%, 0.3% for arthritis, 11.9% for asthma, 0.5% for diabetes and 2.6% for autism. Children with adults reporting higher educational levels had greater odds of allergies (adjusted odds ratio and 95% CI: 1.48, 1.23-1.78) than those with lower educational levels. But for all other diseases, most findings suggested that a higher odds of disease was associated with lower SES instead of higher SES.

CONCLUSIONS

A low SES background remains an important risk factor for hypersensitivity diseases in children. Most of our results suggested that children with low SES were associated with a higher risk of hypersensitivity diseases and autism.

Global, regional and national burden of autism spectrum disorder from 1990 to 2019: results from the Global Burden of Disease Study 2019

AIMS

Autism spectrum disorder (ASD) is a neurodevelopmental condition, with symptoms appearing in the early developmental period. Little is known about its current burden at the global, regional and national levels. This systematic analysis aims to summarise the latest magnitudes and temporal trends of ASD burden, which is essential to facilitate more detailed development of prevention and intervention strategies.

METHODS

The data on ASD incidence, prevalence, disability-adjusted life years (DALYs) in 204 countries and territories between 1990 and 2019 came from the Global Burden of Disease Study 2019. The average annual percentage change was calculated to quantify the secular trends in age-standardised rates (ASRs) of ASD burden by region, sex and age.

RESULTS

In 2019, there were an estimated 60.38 × 104 [95% uncertainty interval (UI) 50.17-72.01] incident cases of ASD, 283.25 × 105 (95% UI 235.01-338.11) prevalent cases and 43.07 × 105 (95% UI 28.22-62.32) DALYs globally. The ASR of incidence slightly increased by around 0.06% annually over the past three decades, while the ASRs of prevalence and DALYs both remained stable over the past three decades. In 2019, the highest burden of ASD was observed in high-income regions, especially in high-income North America, high-income Asia Pacific and Western Europe, where a significant growth in ASRs was also observed. The ASR of ASD burden in males was around three times that of females, but the gender difference was shrunk with the pronounced increase among females. Of note, among the population aged over 65 years, the burden of ASD presented increasing trends globally.

CONCLUSIONS

The global burden of ASD continues to increase and remains a major mental health concern. These substantial heterogeneities in ASD burden worldwide highlight the need for making suitable mental-related policies and providing special social and health services.

Parental Socioeconomic Status and Autism Spectrum Disorder in Offspring: A Population-Based Cohort Study in Taiwan

Studies from the United States have shown increasing incidence of autism spectrum disorder (ASD) with increasing socioeconomic status (SES), whereas in Scandinavian countries, no such relation was identified. We investigated how ASD risk in offspring varied according to parental SES in Taiwan, where there is universal health care. Through linking birth reporting data and data from Taiwan's national health insurance program, we studied 706,111 singleton births from 2004 to 2007 and followed them until 2015. Parental SES was determined by monthly salary at the time of childbirth, and child neuropsychiatric outcomes were defined using International Classification of Diseases codes. We identified 7,323 ASD cases and 7,438 intellectual disability (ID) cases; 17% of ASD cases had co-occurring ID. In multivariable Cox regression analysis, higher SES was independently associated with higher risk of ASD after we took into account urbanization levels, child sex, parental age, and other covariates. By contrast, higher SES was independently associated with lower risk of ID. Besides the SES disparity in ASD case ascertainment and in the access to health care, findings from Taiwan suggest that other social, environmental, biological, and immunological factors linked with parental SES levels may contribute to the positive relation of SES and ASD risk.