All-Cause Mortality and Specific Causes of Death in Autism: A Nationwide Analysis

Abstract

Background:

Western studies have reported a higher mortality risk in autistic individuals. However, the specific causes of death and the roles of age, sex, and concurrent intellectual disability (ID) remain unclear. This study aimed to analyze the causes of death in autism and the moderating effects of age, sex, and concurrent ID.

Methods:

This nationwide population-based study, conducted between 2008 and 2019, identified 64,685 autistic individuals and were age and sex matched with 1,279,174 nonautistic controls. All-cause mortality and specific causes of death were compared between autistic and nonautistic controls. The modifying effects of age, sex, and concurrent ID were also examined.

Results:

The risk of all-cause mortality (hazard ratio = 2.28) is higher in autistic individuals than in nonautistic controls. The elevated all-cause mortality in autistic individuals was consistent across sex, age, and the presence or absence of ID and was higher in autistic women, adults, and those with concurrent ID than in their counterparts. The mortality risks for most examined specific causes, except cancer, are higher in the autistic group than those in nonautistic controls. Although autistic individuals with concurrent ID showed higher mortality risks in neurological, respiratory, and gastrointestinal categories and accidents, the risk of suicide is lower. Autistic women had higher mortality risks in most categories, whereas autistic adults had a higher mortality risk in the neurological and respiratory categories.

Conclusion:

Autistic individuals face higher mortality risks across various disease categories, regardless of sex, age, or concurrent ID. Health care policies should prioritize the implementation of specific strategies for the early detection of diseases and health promotion, as well as accident and suicide prevention among autistic women and those without ID. Clinical Trial Registration number: NCT04010422.

Community brief

Why is this an important issue?

Mortality risk in autism is a crucial concern because it affects the well-being and health of autistic individuals. Recent studies in Western countries have shown that autistic individuals may face a higher risk of premature death, but the reasons behind this are unclear. Understanding the causes of death and the factors that influence it, such as age, sex, and concurrent intellectual disability, can help develop targeted strategies to improve the health and longevity of autistic individuals.

What was the purpose of this study?

The researchers wanted to investigate the mortality risk of autism and understand the factors that might contribute to it. They examined the specific causes of death in autistic individuals and compared them with nonautistic individuals. They also examined how age, sex, and concurrent intellectual disability might influence the mortality risk.

What did the researchers do?

The researchers conducted a large-scale study using nationwide data from 64,685 autistic individuals from 2008 to 2019. They matched these individuals with 1,279,174 nonautistic individuals of the same age and sex. By comparing the two groups, they analyzed the overall risk of death and the specific causes of death. They also studied how age, sex, and the presence or absence of intellectual disability affected the mortality risk.

What were the results of the study?

The study found that autistic individuals had a higher risk of death from any cause (all-cause mortality) than nonautistic individuals. This risk was consistent across all ages, sexes, and whether they had concurrent intellectual disability. The most common specific causes of death in autistic individuals were related to cardiovascular, respiratory, accidents, and neurological disorders.

What do these findings add to what was already known?

This study adds to previous knowledge by confirming that there is indeed a higher mortality risk in autism, regardless of age, sex, or intellectual disability. It highlights specific causes of death, such as cardiovascular and respiratory conditions, where the risk is particularly elevated. In addition, it reveals that accident and suicide prevention should be a priority, especially for autistic females and individuals without intellectual disability.

What are potential weaknesses in the study?

While the study provided valuable insights, there might be some limitations. For instance, the data were based on claims and might not capture all the relevant information about the individuals' health and lifestyle factors. In addition, the study might not have considered all the possible variables that could influence mortality risk in autism.

How will these findings help autistic adults now or in the future?

These findings are essential for the well-being of autistic individuals and their families. Policymakers and health care providers can use this knowledge to develop targeted strategies to reduce mortality risk in autism. By focusing on accident and suicide prevention, particularly for females and those without intellectual disability, health care policies can improve the overall health and life expectancy of autistic individuals. In addition, the study emphasizes the need for better health care services and support for autistic individuals, ensuring that their unique needs are addressed throughout their lives. Ultimately, this research contributes to a better understanding of autism and helps create a more inclusive and supportive society for all individuals on the spectrum.