Autism in England: assessing underdiagnosis in a population-based cohort study of prospectively collected primary care data

ADOS-2 Module 4: Psychometric Properties and Diagnostic Performance at an Autism-specialized Clinic

PURPOSE

Psychometric properties and diagnostic performance of the ADOS-2 module 4 were evaluated with participants from an autism-specialized clinic.

METHODS

The sample had 331 participants with 226 males and 70 females receiving an ASD diagnosis. The evaluation consisted of the following: (1) A replication of the Exploratory Factor Analysis (EFA) reported by Hus, V., & Lord, C. (2014). The Autism Diagnostic Observation Schedule, Module 4: Revised Algorithm and Standardized Severity Scores. Journal of Autism and Developmental Disorders, 44(8), 1996-2012. https://doi.org/10.1007/s10803014-2080-3 .). (2) Identification of ADOS-2 items best predicting clinical diagnosis using Recursive Feature Elimination (RFE) and comparison of these items to previous findings. (3) Receiver Operating Characteristic (ROC) curve analyses of the effects of age and IQ on diagnostic performance. (4) Comparisons of ADOS-2 revised algorithm scores between females and males and their association with ADI-R scores.

RESULTS

The EFA item-to-factor allocation of the ADOS-2 revised algorithm was largely reproduced. When comparing the present RFE to previous RFE findings, the item Quality of Social Responses stood out. ROC curve analysis showed outstanding diagnostic performance for adults with IQ above 70 but for females, ADOS-2 revised algorithm scores were lowered, and, contrary to males, did not correlate with ADI-R scores.

CONCLUSION

Reproducing the item-to-factor allocation and finding outstanding agreement with the diagnostic decision for adults with IQ > 70 showcase the strength of the ADOS-2 revised algorithm. Furthermore, by incorporating, into future revisions, the finding of inter-clinic importance of the item Quality of Social Responses, performance might be further enhanced. Lastly, though, that female scores were lowered and did not correlate with ADI-R indicate a weakness in the ADOS-2 when applied to the adult female population.

Memory strategies in autistic and older adults

Memory strategies in autistic adults seem to mimic strategies at older age, as both younger autistic and older non-autistic individuals use fewer semantic features in visual memory tasks. Therefore, the current study aims to investigate whether early differences in memory strategies lead to altered age-related effects in autism, particularly whether initial difficulties in strategy use become advantageous at older age (i.e., "protective aging"). A total of 147 participants across four groups (autistic younger/older, non-autistic younger/older) completed an online assessment. This assessment included a recognition version of the Visual Patterns Test (VPT) to evaluate semantic strategy use in visual memory, the Just Noticeable Difference (JND) size task for assessing visual processing, and the Multifactorial Memory Questionnaire to evaluate subjective memory functioning and strategy use (MMQ). Unexpectedly, all groups benefited from semantic features on the VPT, although the older groups performed less accurately and slower than the younger groups. The JND Size task showed no group differences. Autistic adults rated their MMQ memory as worse than non-autistic adults, despite reporting greater strategy use. These results indicate that cognitive strategies might be more similar between younger/older and autistic/non-autistic people than previously expected, although notable discrepancies between objective and subjective measures were present. They also substantiate previously reported parallel (i.e., similar) age-related effects between autistic and non-autistic people.

The causal association between maternal depression, anxiety, and infection in pregnancy and neurodevelopmental disorders among 410 461 children: a population study using quasi-negative control cohorts and sibling analysis

BACKGROUND

To address if the long-standing association between maternal infection, depression/anxiety in pregnancy, and offspring neurodevelopmental disorder (NDD) is causal, we conducted two negative-control studies.

METHODS

Four primary care cohorts of UK children (pregnancy, 1 and 2 years prior to pregnancy, and siblings) born between 1 January 1990 and 31 December 2017 were constructed. NDD included autism/autism spectrum disorder, attention-deficit/hyperactivity disorder, intellectual disability, cerebral palsy, and epilepsy. Maternal exposures included depression/anxiety and/or infection. Maternal (age, smoking status, comorbidities, body mass index, NDD); child (gender, ethnicity, birth year); and area-level (region and level of deprivation) confounders were captured. The NDD incidence rate among (1) children exposed during or outside of pregnancy and (2) siblings discordant for exposure in pregnancy was compared using Cox-regression models, unadjusted and adjusted for confounders.

RESULTS

The analysis included 410 461 children of 297 426 mothers and 2 793 018 person-years of follow-up with 8900 NDD cases (incidence rate = 3.2/1000 person years). After adjustments, depression and anxiety consistently associated with NDD (pregnancy-adjusted HR = 1.58, 95% CI 1.46-1.72; 1-year adj. HR = 1.49, 95% CI 1.39-1.60; 2-year adj. HR = 1.62, 95% CI 1.50-1.74); and to a lesser extent, of infection (pregnancy adj. HR = 1.16, 95% CI 1.10-1.22; 1-year adj. HR = 1.20, 95% CI 1.14-1.27; 2-year adj. HR = 1.19, 95% CI 1.12-1.25). NDD risk did not differ among siblings discordant for pregnancy exposure to mental illness HR = 0.97, 95% CI 0.77-1.21 or infection HR = 0.99, 95% CI 0.90-1.08.

CONCLUSIONS

Maternal risk appears to be unspecific to pregnancy: our study provided no evidence of a specific, and therefore causal, link between in-utero exposure to infection, common mental illness, and later development of NDD.

"A perfect storm": Autistic experiences of menopause and midlife

LAY ABSTRACT

Previous studies report that menopause can be a very difficult transition for some autistic people. This study focuses on how autistic people experience menopause and what support and information might help them. Autistic Community Research Associates played an important role in the research and co-authored this article. We held four focus groups and eight interviews online with 24 autistic participants who lived in either Canada (n = 13) or the United Kingdom (n = 11). We analysed participant conversations using a method called reflexive thematic analysis. Participants described many intense challenges during menopause. Four themes and eight subthemes were identified across participant groups: (1) Complexity, multiplicity and intensity of symptoms (0 subthemes); (2) Life experience and adversity converging at midlife (three subthemes); (3) The importance of knowledge and connection (two subthemes); and (4) Barriers to support and care (three subthemes). The experiences of our participants may not be the same as other autistic people, and the study could have been more inclusive of diverse autistic groups. However, hearing about the experiences of others may provide reassurance to autistic people who struggle with menopause and let them know they are not alone.

Comparison of network structures between autistic and non-autistic adults, and autism subgroups: A focus on demographic, psychological, and lifestyle factors

LAY ABSTRACT

There are large differences in the level of demographic, psychological, and lifestyle characteristics between autistic and non-autistic adults but also among autistic people. Our goal was to test whether these differences correspond to differences in underlying relationships between these characteristics-also referred to as network structure-to determine which characteristics (and relationships between them) are important. We tested differences in network structure in (1) autistic and non-autistic adults and (2) two previously identified subgroups of autistic adults. We showed that comparing networks of autistic and non-autistic adults provides subtle differences, whereas networks of the autism subgroups were similar. There were also no sex differences in the networks of the autism subgroups. Thus, the previously observed differences in the level of characteristics did not correspond to differences across subgroups in how these characteristics relate to one another (i.e. network structure). Consequently, a focus on differences in characteristics is not sufficient to determine which characteristics (and relationships between them) are of importance. Hence, network analysis provides a valuable tool beyond looking at (sub)group level differences. These results could provide hints for clinical practice, to eventually determine whether psychological distress, cognitive failures, and reduced quality of life in autistic adults can be addressed by tailored support. However, it is important that these results are first replicated before we move toward intervention or support.

The relationship between clinical presentation and the nature of care in adults with intellectual disability and epilepsy - national comparative cohort study

BACKGROUND

A quarter of People with Intellectual Disabilities (PwID) have epilepsy compared with 1% of the general population. Epilepsy in PwID is a bellwether for premature mortality, multimorbidity and polypharmacy. This group depends on their care provider to give relevant information for management, especially epilepsy. There is no research on care status relationship and clinical characteristics of PwID and epilepsy.

AIM

Explore and compare the clinical characteristics of PwID with epilepsy across different care settings.

METHOD

A retrospective multicentre cohort study across England and Wales collected information on seizure characteristics, intellectual disability severity, neurodevelopmental/biological/psychiatric comorbidities, medication including psychotropics/anti-seizure medication, and care status. Clinical characteristics were compared across different care settings, and those aged over and younger than 40 years.

RESULTS

Of 618 adult PwID across six centres (male:female = 61%:39%), 338 (55%) received professional care whereas 258 (42%) lived with family. Significant differences between the care groups existed in intellectual disability severity (P = 0.01), autism presence (P < 0.001), challenging behaviour (P < 0.001) and comorbid physical conditions (P = 0.008). The two groups did not vary in intellectual disability severity/genetic conditions/seizure type and frequency/psychiatric disorders. The professional care cohort experienced increased polypharmacy (P < 0.001) and antipsychotic/psychotropic use (P < 0.001/P = 0.008).The over-40s cohort had lower autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) comorbidity (P < 0.001/P = 0.007), increased psychiatric comorbidity and challenging behaviour (P < 0.05), physical multimorbidity (P < 0.001), polypharmacy (P < 0.001) and antipsychotic use (P < 0.001) but reduced numbers of seizures (P = 0.007).

CONCLUSION

PwID and epilepsy over 40 years in professional care have more complex clinical characteristics, increased polypharmacy and antipsychotic prescribing but fewer seizures.

A qualitative evaluation of the pathway for eating disorders and autism developed from clinical experience (PEACE): clinicians' perspective

Introduction

The Pathway for Eating disorders and Autism developed from Clinical Experience (PEACE pathway) is a clinical pathway of adapted treatment for individuals with eating disorders and autism in the UK. This study aims to investigate multidisciplinary clinicians' views of the strengths and challenges of PEACE pathway adaptations, while identifying areas where further improvement is needed.

Method

Semi-structured interviews were conducted with 16 clinicians who worked on the PEACE pathway. Themes relevant to the benefits, challenges and areas of improvement were identified, and a thematic map was produced.

Results

PEACE Pathway brought clinical benefits such as improved understanding of patients' perspective, improved flexibility and individualisation in clinicians' approach, increased patient engagement, and provision of resources that are helpful to all patients with or without autism. Benefits to the service included increase in autism awareness, clinicians' confidence, and team collaboration. Challenges were also identified, including difficulties in incorporating autism adaptations into existing treatment protocol, implementing PEACE at different levels of care, staff schedule conflicts, and increased pressure to meet patients' needs. Overall, there is a need for systemic improvement in aftercare and community support for autism, more suitable autism screening tool, and more structured guidelines for making adaptations.

Conclusions and implications

PEACE Pathway has brought clinical and service benefits, while also bringing practical challenges rooted in the difficulty in distinguishing between autism and eating disorder in comorbid population. Future areas of improvement are highlighted for PEACE resources as well as in the national support system for autistic individuals.

A comparison of the presentations of males and females with autism spectrum disorder and those narrowly below the diagnostic threshold

LAY ABSTRACT

Most research about autism spectrum disorder (ASD) in females has looked at autistic features in people who have already received diagnoses. Because our understanding of ASD has been shaped by the difficulties of males, females may experience different difficulties and may not meet the criteria for diagnosis because of a skewed concept of ASD. We extracted detailed information from the assessment reports of 222 children who were either diagnosed with ASD (156 children) or not diagnosed despite many ASD traits (78 children). Females were less likely to have restricted interests, especially females who did not receive an ASD diagnosis. Females who did not receive an ASD diagnosis tended to show more ability in social and emotional reciprocity than what would qualify them for a diagnosis. We also found sex-/gender-specific profiles of body use and speech mannerisms. Many behaviours were more closely linked with an ASD diagnosis for males and others for females, suggesting that behaviours may be interpreted differently depending on the child's sex/gender. We discuss implications for assessing females for ASD in the context of this evidence.

Improving Diagnostic Procedures in Autism for Girls and Women: A Narrative Review

Biases exist in the diagnostic process for autism spectrum disorder (henceforth "autism"), which result in some girls and women being diagnosed later or missed entirely. Current diagnostic tools may not capture the full range of behavioural presentations of autism, leading to under-identification. This review explores why these biases may occur, and how diagnostic procedures could be adapted to better identify autistic girls and women. We recommend that diagnostic assessments are adjusted to capture a broader range of behavioural exemplars of autism; that camouflaging of autistic traits is taken into account; and that care is taken to ensure co-occurring mental health conditions do not overshadow autism diagnosis. We offer recommendations, building on gold-standard diagnostic guidelines, for how diagnostic procedures can be improved for girls and women.

Large increase in ASD prevalence in Israel between 2017 and 2021

Accurate estimation of annual changes in autism spectrum disorders (ASD) prevalence is critical for planning the expansion of diagnostic, education, and intervention services at an adequate rate. Previous studies from Israel have reported that ASD prevalence among 8-year-old children has increased from estimates of 0.3% in 2008 to 0.65% in 2015 and 1.3% in 2018. Here, we analyzed data acquired from the National Insurance Institute of Israeli (NII), a governmental organization that approves and monitors all ASD children who receive welfare services in Israel, and Clalit Health Services (CHS), the largest Health Maintenance Organization in Israel that provides health services to ~52% of the population. Data from both sources included annual data files from 2017 to 2021 containing the number of ASD cases per year of birth for 1-17-year-old children. This allowed us to estimate annual ASD prevalence among 3.5 million children born between 2000 and 2020 in Israel. Both data sources revealed a nearly two-fold increase in ASD prevalence among 1-17-year-old children from 2017 to 2021. Estimated prevalence rates differed across age groups with 2-3-year-old (day-care) children increasing from 0.27% to 1.19% (>4 fold change), 4-6-year-old (pre-school) children increasing from 0.8% to 1.83%, and 8-year-old children increasing from 0.82% to 1.56% in NII data. These results demonstrate that autism prevalence continues to increase in Israel with a shift towards diagnosis at earlier ages. These findings highlight the challenge facing health and education service providers in meeting the needs of a rapidly growing autism population.

The Association between Threatened Miscarriage and Autism Spectrum Disorder and Attention-Deficit/Hyperactivity Disorder in Offspring by Age 14 Years

OBJECTIVE

To examine the association between threatened miscarriage, and neurodevelopmental disorders, including autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in offspring by age 14 years.

METHODS

We used data from the Millennium Cohort Study, a nationally representative longitudinal study of children born in the UK. Data on threatened miscarriage and potential confounders were maternal-reported and collected at 9 months postpartum. Data on ASD and ADHD were based on maternal-reported doctor diagnoses and collected when children were aged 5, 7, 11 and 14 years. A diagnosis of ASD or ADHD was assumed if parents reported ASD or ADHD at age 5, 7, 11 or 14 years. Crude and adjusted logistic regression examined threatened miscarriage and ASD and ADHD relationship, adjusting for several sociodemographic, maternal and lifestyle factors.

RESULTS

A total of 18,294 singleton babies were included at baseline, and 1,104 (6.0%) women experienced a threatened miscarriage during their pregnancy. Adjusted results suggested an association between threatened miscarriage and ASD (OR: 1.55, 95% CI 1.15, 2.08), and ADHD (OR: 1.51, 95% CI 1.09, 2.10) by age 14 years. E-values for threatened miscarriage and ASD were 2.47, while the lower limits of the 95% CI were 1.57. E-values for threatened miscarriage and ADHD were 2.39, while the corresponding lower limits of the 95% CI were 1.40.

CONCLUSION

Threatened miscarriage was associated with an increased likelihood of ASD and ADHD by the age of 14 years, however, residual confounding cannot be ruled out. Placental pathology may be a potential mechanism for the observed associations.

The association between social camouflage and mental health among autistic people in Japan and the UK: a cross-cultural study

BACKGROUND

To examine the relationship between social camouflage and mental health in Japanese autistic adults and make an international comparison with a sample from the UK.

METHODS

This study analysed secondary data of participants with a self-reported diagnosis of autism from Japan (N = 210; 123 men and 87 women) and the UK (N = 305; 181 women, 104, men, and 18 nonbinary). The relationships between the quadratic term of the Camouflaging Autistic Traits Questionnaire and mental health scales, including depression and anxiety, were assessed.

RESULTS

The UK sample showed linear relationships, whereas the Japanese sample showed significant nonlinear relationships. The quadratic terms of the Camouflaging Autistic Traits Questionnaire slightly explained generalised anxiety (β = .168, p = .007), depression (β = .121, p = .045), and well-being (β = - .127, p = .028). However, they did not explain the association between social anxiety and the Camouflaging Autistic Traits Questionnaire.

LIMITATIONS

Participants had self-reported diagnoses, and while the autism-spectrum quotient provides a cut-off value for screening, it does not enable confirming diagnoses. Mean scores of the Japanese version of the Camouflaging Autistic Traits Questionnaire were lower as compared to the original CAT-Q, which implies that the social camouflage strategy types used by autistic people in Japan and the UK could differ. The cross-sectional design limits causal inferences.

CONCLUSION

In the UK, more social camouflage was associated with poorer mental health scores, whereas too little or too much social camouflage was associated with a low mental health score in Japan. The Japanese population is seemingly less aware of and educated on autistic characteristics and considers 'average' behaviour a good thing. This could influence Japanese autistic people's social camouflage use, differing from that of autistic people in the UK. The differences in the relationship between social camouflage and mental health between Japan and the UK could be associated with national-level divergence regarding the culture of autism.