Introduction

Autism spectrum disorder (ASD, autism) is a complex, life-long disorder characterized by two core symptoms, which range in severity: persistent deficits in social communication and social interaction, and restricted and repetitive patterns of behaviors.1 ASD affects ~1 in 160 children globally2 and contributes to significant social (quality of life) and economic impacts (lifetime cost USD1.4 million and GBP0.80 million) that increase with ASD symptom severity.3,4,5

Autism is associated with a wide range of co-occurring developmental, mental, and physical health conditions, including intellectual disability (ID), epilepsy, attention-deficit hyperactivity disorder (ADHD), anxiety, depression, behavioral disturbances and tics, abnormal sleep patterns, motor difficulties, eating and elimination disorders, diabetes, hypertension, obesity, and cardiovascular disease.6,7,8 Each individual with autism has a unique life experience with different onset, combinations, severities, and persistence of ASD symptoms and co-occurring conditions. Accordingly, there is no one-size-fits-all healthcare approach, and healthcare must be agile, responsive, and, above all, accessible.

Despite the growing body of evidence, our understanding of barriers to healthcare encountered by autistic individuals remains limited, particularly beyond childhood and outside of higher resource countries (HRCs). In this review, we present an integrated understanding of healthcare needs and barriers encountered in HRCs, highlight gaps in our knowledge, and uncover important steps that stakeholders can take to improve healthcare service provision and enhance healthcare access for all individuals with ASD.

Methodology

This review is based on an extensive search of scholarly/peer-reviewed and gray literature. Our search of scholarly/peer-reviewed literature was carried out in PubMed using MeSH terms for autism keywords (e.g., autism spectrum disorder, autism, Asperger syndrome), socioeconomic impact (e.g., burden, caregiver, carer, socioeconomic), and access to healthcare (e.g., access, barriers, inequality, disparity). Gray literature was identified by reviewing publications covering socioeconomic impacts of ASD and barriers to healthcare access for autistic individuals released by organizations such as national ministries of health/public health agencies and autism-focused non-governmental organizations. Relevant articles referenced in publications identified from our search were also reviewed. We retrieved 1509 publications and assessed titles and abstracts/summaries to prioritize 248 publications for deeper review. Our search focused on literature published in or after 2010.

Common barriers to accessing medical care

A review of the literature helps characterize common barriers encountered across the lifespan, how they reduce access to care, existing solutions that address barriers and gaps in our understanding of their impact on long-term health, and social or economic outcomes.

Shortage of healthcare services

Families living outside metropolitan areas have less access to care for ASD than those in urban areas, often due to a shortage of specialists.9,10 In the USA, the number of child and adolescent psychiatrists per 100,000 ranges from 5 in Idaho (many rural communities) to 60 in the District of Columbia (densely populated).11 Similarly, the number of developmental-behavioral pediatricians per 100,000 children is 0.2 in Idaho and 4 in the District of Columbia.12 This results in a service supply shortage, clinician burnout, and long wait times for diagnosis and treatment.13 Families that do not have access to care in their community are less likely to seek care due to the additional cost, time commitment and disruption to daily obligations (e.g., work) associated with long-distance travel.14,15,16 Tools such as the Extension for Community Healthcare Outcomes (ECHO) Autism Screening Tool for Autism in Toddlers and Young Children (STAT) that connects local physicians to a hub of autism experts are increasing the capacity to screen, diagnose, and treat autism in rural communities; however, additional research is needed to optimize the accuracy of diagnosis using telemedicine and videoconferencing.17,18

Physician knowledge

Delivering the best care to autistic individuals critically depends on physician knowledge and training. Unfortunately, many individuals with ASD, their families, and even physicians have reported that physicians can lack specialized knowledge required to screen, diagnose, and refer individuals with ASD.14,19,20 Further, US medical students have reported not receiving sufficient training on treating autistic children, while those from the UK reported low confidence in their ability to manage care and referral of children and adults with ASD.21,22 Autistic individuals and their caregivers also see a need for physicians to have a better understanding of how to support individuals with severe ASD symptoms, facilitate more effective communication, and accommodate sensory challenges.15,23,24,25,26,27 Initiatives that improve physician awareness in screening and diagnosis of young children show promise, including the ECHO Autism STAT program (described above), which has been implemented in the USA, Canada, Uruguay, Kenya, India, and Vietnam, resulting in patients accessing services 2–6 months sooner.17,28 In addition, AASPIRE’s Autism Healthcare Accommodations Tool—a customized communication and sensory accommodations report builder—has decreased the number of barriers to care faced by autistic adults by 30%, and improved healthcare provider self-efficacy and patient–provider communication.29

Cost of services: the US example

Consistent with the use of a wide range of healthcare services across the lifespan, the cost of healthcare for individuals with ASD is very high. In the USA, annual healthcare costs for autistic individuals increase with age from USD6467 (age 0–5 years) to USD9053 (age 6–17 years) to USD13,580 (age 18+ years) and are significantly higher for individuals with co-occurring ID.3 The amount of out-of-pocket healthcare expenditures also depends on individual health insurance coverage and household income. Indeed, recommended ASD services are often excluded from insurance plans held by families with lower socioeconomic status (SES).30 In recent years, as all 50 US states mandated private health insurance companies to cover diagnostic and treatment services for ASD, healthcare service utilization has increased, suggesting that insurance coverage addresses, at least in part, the financial barrier to accessing healthcare.31,32

Family and individual knowledge

When individuals with ASD and their families know the signs and symptoms of ASD and available care options, they are more likely to alert care providers to a developmental delay and/or advocate for healthcare services. However, building this knowledge can be influenced by situational and social factors. For example, first-time parents are less likely to detect developmental delays than experienced parents who are often more familiar with typical developmental milestones.33 Reduced awareness of ASD and related services is more common in groups with lower SES, less education, and limited access to health professionals (e.g., those living in rural areas).9 The World Health Organization (WHO) has developed and implemented Caregiver Skill Training (CST) programs in over 30 countries, which boosts family awareness of ASD needs and services in local contexts.34,35

Language

Language barriers also hinder access to and navigation of healthcare services for ASD. In Canada, the USA, and the UK, parents of children with ASD, for whom English is not the first language, encountered language barriers when accessing health services, communicating with their physicians, and interpreting/responding to administrative forms.36,37,38 Recognizing this shortcoming, several organizations, such as Autism Speaks and the University of Southern California, Center for Excellence in Developmental Disabilities, have translated key resources describing the signs of autism, outlining steps to take when signs are detected, and summarizing support available to families into multiple languages.39,40

Stigma

As with many mental health disorders, stigma can contribute to feelings of rejection and isolation among parents of autistic children and can prevent individuals with ASD from engaging with the healthcare system at all stages of life.20,41,42 While stigma is a reality for most families affected by ASD, its impacts on access to diagnosis and treatment services are exacerbated for many racial/ethnic minorities (including immigrants).36,38 Studies from Canada, UK, and the USA have determined that immigrant parents from some cultures do not acknowledge that their children have developmental disabilities because of the associated stigma.36,38 Advocacy and research groups have launched initiatives that have reduced stigma around ASD. For example, Sesame Workshop worked with over 13 autism-related organizations to introduce a Muppet with autism to the television show and digital resources. Sesame Workshop has received global praise for the depiction of a child with ASD and for increasing knowledge, acceptance, and inclusion of autistic children.43,44

Childhood (0–17 years of age)

One of the greatest healthcare needs for children with ASD is securing an accurate clinical diagnosis of ASD and any comorbid conditions. Diagnoses enable primary care practitioners (PCPs) to initiate an individualized cascade of care—including educational, therapeutic, medical, genetic counseling, and family support services—which is recommended by many professional associations.45,46,47,48,49 While this cascade is well defined, many of the barriers to healthcare (described above) can be exacerbated at this stage of life by a number of factors—which can intersect and interact in unique ways for each individual:

  • Symptom severity: ASD is a spectrum disorder and individuals experience diverse symptoms that can range from mild to severe. This heterogeneity can make it difficult for physicians to consistently identify early signs of developmental delays and/or ASD in children.50 Less severe ASD symptoms are often not detected by clinicians until later in life.51

  • Comorbid health conditions: autistic individuals often have comorbid health conditions that can be conflated with ASD symptoms, complicating or delaying diagnosis.52 In addition, comorbid health conditions are managed within the healthcare system, while developmental disabilities (including ASD) are typically supported within the social services and education systems, making it difficult to integrate care.53

  • Differing expression of ASD symptoms: ASD symptoms can be expressed in different ways. For example, females—who often have a different clinical presentation of ASD than males—are commonly diagnosed later in life despite typically being assessed for developmental delays at the same age as boys.54,55

Parents of children with ASD report first having concerns about their child’s development as early as 12–18 months of age and some clinicians are able to diagnose ASD as early as 14 months;56,57 however, diagnosis typically occurs later in Europe (3.5 years), USA (4 years), and Canada (6 years), exposing an opportunity to decrease the age at diagnosis and accelerate access to specialized healthcare.58,59,60 Early diagnosis and treatment have been linked to greater reduction in the core symptoms of ASD, higher likelihood of receiving behavioral therapy, and a reduction in the use of psychotropic medication.61,62,63 Yet, little is known about how it can contribute to higher quality of life over time or to better long-term health outcomes such as life expectancy and severity of comorbid conditions.

Several professional associations recommend that diagnosis of ASD should be followed by genetic (including mitochondrial disorders) and metabolic screening to identify syndromes (e.g., Fragile X) or potentially treatable neurometabolic causes of ASD.64,65,66 This screening can potentially uncover a unifying cause for symptoms of ASD and some comorbid health conditions (e.g., ID, epilepsy), rule out certain mental health disorders, and support physicians in making evidence-based referrals. Despite these recommendations, limited insurance coverage or lack of information regarding the availability and benefits of genetic and metabolic screening prevent some families from accessing this service.67

Transition to adulthood (~16–25 years of age)

Every year, over 50,000 youth with ASD enter adulthood in the USA.68 A smooth and timely transition from a pediatric to an adult PCP is critically important to young adults with ASD having the medical support they need at a time when both the incidence and severity of many mental and physical health comorbidities increase.69,70,71 However, autistic youth transitioning to adulthood are often reluctant to seek support for their mental health due to social stigma and uncertainty around where to go for care, often leading to the worsening of symptoms.72

Health systems in HRCs have established and implemented healthcare transition (HCT) services to foster continuity between pediatric and adult care. However, HCT services have been difficult to scale—one study found that only one-fifth of autistic youth received HCT services—and many youths with ASD face challenges accessing healthcare.73,74 This may partly explain why scheduled outpatient and inpatient visits decline with age for autistic youth, especially for those with a co-occurring ID75 and why the use of emergency services increases.69,70 A Canadian study reported that 70% of pediatricians did not support youth with ASD in the transition to adult healthcare services and another study found that >50% of families lacked information on the HCT process.19,76 Physicians may feel that HCT services are better suited to lower-functioning autistic individuals and may not be clear on how to include individuals with moderate or mild ASD symptoms in the transition process, underscoring the opportunity to tailor HCT services to the unique needs of individuals with ASD. Further, multiple studies found that there is a lack of adult care physicians who have specialized understanding of the medical, behavioral, and social needs of individuals with ASD during transition.19,77 Topics that could be better addressed during physician training to foster more effective relationships and communication between the patient and provider include sensory sensitivities, value of routine experience, and benefits of preparing autistic adults in advance of appointments.78 A recent adaptation of ECHO, known as ECHO Autism Transition, was successfully piloted to train PCPs on improving self-efficacy in caring for autistic individuals as they transition to adulthood.79

Adulthood (>18 years of age)

As the rate of childhood diagnosis increases, the number of aging individuals with ASD will continue to rise. Based on a recent statistical model using data from the National Study of Children’s Health, 2.2% of US adults are estimated to have ASD.80 Autistic adults encounter many health issues including mental health difficulties (e.g., associated with social disengagement, loneliness, depression, and anxiety) and physical health conditions (e.g., obesity, heart disease).81,82 Adults with ASD also have an increased risk of premature mortality compared to the general population (mean age of mortality: 54 vs 70 years), especially for those who are low functioning (mean age of mortality: 40 years).83 While research on interventions to improve health outcomes in autistic adults is emerging,84 limited research on healthcare barriers indicates that health services, funding, and physician training are not yet meeting the needs of this population.85,86

Long waitlists and lack of funding are major barriers to treatment and support for autistic adults in the UK, forcing many to pay for treatment themselves.87 While in the USA, autistic adults are often unable to find care that addresses developmental delay together with mental health issues and frequently lack the personal funds or insurance coverage to cover the cost of care.88 In fact, adults with ASD, who request help for anxiety or depression and mention their ASD, are often “punted” to a provider with experience in developmental delays who may not have expertise in mental healthcare (or vice versa). Similar to other life stages, both physicians and autistic adults have reported an opportunity to enhance the training of physicians89,90 and caregivers in long-term or residential care facilities.86 Notably, many autistic adults and their families feel that healthcare providers have misconceptions about individuals with autism and commonly over-attribute behaviors to autism instead of looking for a separate illness first.20 Adults with autism also have significantly lower satisfaction scores on patient–provider communication scales.91 Poor communication and common misconceptions (e.g., adults with ASD are not sexually active) may also lead to key health procedures—such as Pap smears or other reproductive health procedures—being overlooked.91,92

There is a need to gather more data on the specific medical needs and barriers to accessing healthcare among adults with ASD to better support this growing population. Notably, little is known about the effects of co-existing psychiatric conditions, long-term pharmacological treatment of comorbidities, and how cognitive decline and dementia affect autistic adults.93 Adult care physicians should also continue to monitor symptoms of ASD—which can intensify and diminish—to guide diagnoses and treatment choices.

Accessing healthcare in lower resource countries

The majority of autistic individuals in lower resource countries (LRCs) do not have access to the healthcare necessary to support their medical needs, and experience many of the barriers described above, especially lack of services, high costs, shortage of physician knowledge, and stigma.94,95,96,97 Yet, most of the studies on barriers to healthcare faced by individuals with ASD have been conducted in HRCs. Of the few studies on barriers to healthcare that have been conducted in LRCs, most focus on children, making it difficult to identify regionally relevant approaches to improving access to care for adults.

Effective community-delivered programs have been implemented in many LRCs to increase access to care. These include the WHO-led CST programs (described above), which are active in several LRCs, including the Philippines, Ethiopia, and China,34,35,98 and PASS Plus, a program delivered in rural India, which integrates support for autism comorbidities.99 These initiatives could be modified and adapted to an online delivery format to train families in LRCs on the medical needs of autistic individuals and provide information on navigating local healthcare systems.

The future of ASD screening, diagnosis, and treatment

Determining the etiology of ASD through genetic screening is part of standard clinical practice in many HRCs (see also section “Common barriers to accessing medical care”). While the heritability of ASD has been estimated to be ~80%, only 10–36% of autistic individuals have an identifiable genetic etiology.100,101,102 Whole-exome sequencing detected etiologic genetic/neurometabolic causes of ID (with or without autism) in 68% of patients tested and has been used to inform tailored and cost-effective medical treatments (e.g., nutritional manipulation) beyond genetic counseling for 44% of patients.103 Similarly, several genetic syndromes associated with ASD have specific co-occurring medical conditions with treatment implications104 or that require ongoing surveillance,105 such as cancer surveillance in individuals with ASD who have germline heterozygous PTEN mutations.106 This points to an opportunity to continue to identify and characterize underlying genomic profiles of ASD (and associated comorbidities) with the potential to personalize ongoing treatment plans.

Complementing smaller-scale research studies, Individualized Treatments for Autism Response using Genetic-Environment Targets (iTARGET; Canada) and the Research Domain Criteria (RDoC; USA) help to determine how genetic and neurobiological profiles can define autism subtypes and inform personalized care for individuals based on both causes and symptoms.107,108 While advances in ASD screening have the potential to improve diagnosis and care, they also have the potential to increase the disparity in care between higher and lower resource settings. Further, in the USA, despite recommendations, disadvantaged groups have less access to genetic testing and counseling, and in Canada’s government-regulated health system, block funding for autistic children is based on the diagnostic label (not the need), and omits funding for testing/counseling for cause, anticipatory needs, or optimized treatments.67,109 As new screening, diagnostic and treatment approaches are developed, all stakeholders, including policymakers, must work together to limit barriers and foster the best possible outcomes for all individuals affected by ASD.

Discussion and recommendations

This review offers a unique contribution to the literature through an integrative review of barriers to healthcare experienced by individuals with autism across the lifespan within the context of healthcare service provision. Recent reviews have been published with a focus on barriers experienced by autistic individuals and their carers when accessing healthcare.26,27 The findings from this review reinforce those brought forward in these studies, including the need to improve physician knowledge and better adapt care environments to sensory sensitivities, while other themes such as challenges experienced by individuals with autism when communicating healthcare needs to providers were not as prominent in our study. Bradshaw et al.25 identify unique healthcare needs among adults with autism that can be improved in the context of healthcare service provision. Our study determines that many of the same barriers are encountered at other life stages, including those related to SES (cost of service, individual/family knowledge), insufficient physician training, and lack of clear referral pathways.25 Nicolaidis et al.20 assessed the healthcare experiences of autistic adults and determined that factors at the patient, provider, and system levels impact the quality of a healthcare experience. Our findings support those of Nicoladis et al., in adulthood, and also determine that the same factors are at play during childhood and the transition to adulthood. We build on the existing body of work by identifying additional barriers encountered by autistic people when seeking or receiving healthcare services across the lifespan. Addressing the barriers to healthcare access (summary in Fig. 1) identified in our review for individuals with ASD requires stakeholders to come together to:

Fig. 1: Barriers to healthcare encountered by individuals with autism spectrum disorder (ASD).
figure 1

Summary of unique barriers to healthcare experienced by autistic individuals during distinct life stages (top panel) and common barriers to healthcare encountered throughout the lifespan (bottom panel).

1. Systematically identify healthcare needs and barriers to healthcare access encountered by subpopulations, particularly underserved populations, to inform the development of tailored solutions: while individuals with ASD have a greater need for healthcare services, they also have less access to appropriate healthcare, even when compared to individuals with other developmental disorders.110 Researchers, care providers, and others within the autism community should dedicate resources to better characterize the healthcare needs and barriers faced by individuals with ASD across the lifespan. Notably, there is a need to focus on underserved populations, including individuals from rural/remote regions; low SES; minoritized groups; and adults.

2. Develop programs in medical and healthcare professional curricula to increase physician knowledge of the standard of care for autistic individuals: there is an opportunity to better prepare physicians to care for individuals with autism to ensure they apply appropriate tools, technologies, and approaches to care (e.g., HCT, management of sensory sensitivities). Faculties of medicine and organizations that accredit medical school curricula and develop healthcare standards should ensure that training reflects current best practices in care for autistic individuals across the lifespan.

3. Continue to develop programs that foster public awareness of ASD to optimize early screening and diagnosis and facilitate access to healthcare for people with ASD: although current assessment tools can diagnose ASD as early as 14 months of age, diagnosis continues to occur much later in life.57,59 Advocacy groups, ASD-focused charities/foundations, and public health organizations should continue to deploy existing and new programs and educational campaigns that focus on reducing stigma and empowering people with ASD and their families with the knowledge to seek early support/diagnosis. Personalizing delivery of information and making resources available in multiple languages and for diverse cultures will facilitate the objectives defined by Autism-Europe,49 best represented in the WHO Mental Health Quality Rights Initiative.111

4. Continue to promote genetic screening following ASD diagnosis and invest in identification/validation of autism subtypes defined by scalable and cost-effective biomarkers: genetic screening has the potential to be used to diagnose ASD earlier in life and, in some instances (e.g., if an older sibling has ASD), may be considered prior to diagnosis.112 While microarray is the current standard of care, exome sequencing with copy number variation analysis has demonstrated significantly higher yield and can be used to inform patient management.101,103 Advancing the potential of genetic screening requires more research on the genetics of ASD, including the potential value of newborn testing, expanding our understanding of ASD etiology, accelerating time to diagnosis, and informing individualized treatment plans stratified by specific autism subtypes and respective biomarkers. Physician associations should continue to promote genetic screening following ASD diagnosis, while advocacy groups can bring focus to educating physicians, the public, and third-party payers on the health and economic benefits of genetic screening. As costs decrease and technology and bioinformatics improve, widespread adoption and insurance coverage of exome or genome sequencing should be considered.

5. Understand specific healthcare needs of individuals with ASD in LRCs and develop programs to increase capacity for early diagnosis and healthcare for ASD: recognizing our incomplete understanding of the healthcare needs of individuals with ASD in LRCs, there is an opportunity to increase country- or region-specific research to understand the current state of ASD (e.g., prevalence, availability of/barriers to healthcare) and support needs (e.g., increasing awareness, existing healthcare services). Existing programs such as CST can be modified and delivered in countries where it is not yet implemented, while new programs are developed to meet context-specific barriers. With the increasing adoption of telemedicine (e.g., during the COVID-19 pandemic) and access to the internet in LRCs, the development of online resources and program delivery presents a powerful opportunity to improve healthcare access for autistic individuals and their caregivers.

6. Conduct longitudinal studies in diverse populations and geographies to understand the long-term health, social and economic impacts of increasing access to healthcare across the lifespan: we have limited understanding of the socioeconomic impacts of autism across the lifespan on individuals, families, and society. Researchers should work together with individuals with autism/their families, advocacy groups, health system leaders, and policymakers to design longitudinal studies, address stakeholder interests, and inform relevant policies/programs.113,114 These studies should include populations from across the globe, in order to build a robust understanding of the global impacts of autism and enable stakeholders, including health systems, policymakers, and insurance companies, to measure and compare the success of new programs/policies aimed at increasing access to healthcare.

Many of the barriers to healthcare faced by autistic individuals also affect individuals with other psychiatric and developmental disabilities (e.g., ID, ADHD). While the recommendations above (summarized in Table 1) are focused on ASD, stakeholders should come together to codevelop solutions that are applicable to multiple psychiatric and developmental disabilities in order to maximize cost-effectiveness and impact on those in need.

Table 1 Recommendations to improve healthcare access for individuals with ASD.