A comparison of autism prevalence trends in Denmark and Western Australia

Functional echolalia in autism speech: Verbal formulae and repeated prior utterances as communicative and cognitive strategies

Echolalia, the echoing of prior speech, is a typical characteristic of autism. Long considered meaningless repetition to be avoided, echolalia may in fact be used functionally in autism. This paper explores the functions of echolalia by children with autism. Based on two prior studies, we designed an elicitation task involving images of 12 professions (teacher) and 12 objects (birthday cake) commonly associated with given conventionalized expressions in Mandarin (e.g., "sheng ri kuai le!" 'Happy birthday!'). Eight Chinese children with autism (mean age: 55.50 ± 8.64) were asked to name and describe these images. All our participants produced a relatively high proportion of echolalia, mostly for naming, description, and topic development, a small percentage being used as conversation maintenance strategy or as cognitive strategy. This indicates that echolalia is often used communicatively in autism speech.

The global prevalence of autism spectrum disorder: A three-level meta-analysis

Autism spectrum disorder (ASD) is one the most disabling developmental disorders, imposing an extremely high economic burden. Obtaining as accurate prevalence estimates as possible is crucial to guide governments in planning policies for identification and intervention for individuals with ASD and their relatives. The precision of prevalence estimates can be heightened by summative analyses of the data collected around the world. To that end, we conducted a three-level mixed-effects meta-analysis. A systematic search of the Web of Science, PubMed, EMBASE, and PsycINFO databases from 2000 up to 13 July 2020 was performed, and reference lists of previous reviews and existing databases of prevalence studies were screened. Overall, 79 studies were included in the analysis of ASD and 59-in the analysis of previously existing relevant diagnoses: 30 for Autistic Disorder (AD), 15 for Asperger Syndrome (AS), and 14 for Atypical Autism (AA) and Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS); these research reports covered the period from 1994 to 2019. Pooled prevalence estimates were 0.72% (95% CI = 0.61-0.85) for ASD, 0.25% (95% CI = 0.18-0.33) for AD, 0.13% (95% CI = 0.07-0.20) for AS, and 0.18% (95% CI = 0.10-0.28) for the combined group of AA and PDD-NOS. Estimates were higher (1) for the studies that used records-review surveillance rather than other designs; (2) in North America compared with other geographical regions; and (3) in high-income compared with lower-income countries. The highest prevalence estimates were registered in the USA. There was an increase in autism prevalence estimates over time. The prevalence was also significantly higher for children aged between 6 and 12 years compared to children under the age of 5 and over the age of 13 years.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42019131525, identifier CRD42019131525.

Attitudes Towards Evidence-Based Practice of Professionals Working with Children and Adolescents with Autism Spectrum Disorder in Bangladesh

Like in many lower-middle-income countries (LMIC), progress in implementing evidence-based practices (EBPs) for children with autism spectrum disorder (ASD) has been slow in Bangladesh. This cross-sectional study examined professionals' attitudes towards evidence-based practice (EBP) for children and adolescents with ASD and explored how providers' demographic factors are related to attitudes to and adoption of EBPs in Bangladesh. The sample consisted of 150 mental health professionals and special teachers from the urban area of Dhaka. Attitudes were assessed by the Evidence-based Practice Attitude Scale-36. Findings indicated that professionals have favorable attitudes towards EBP. Their attitudes varied depending on service settings (public clinical, private clinical, and special school) and caseload per year. Professionals who work in private and special school settings claimed to be more willing to adopt an EBP when required and perceived a higher fit of EBPs and their work than those in public clinical settings. The number of different EBPs used also differed by service setting. Every type of intervention (except medication) was used by more professionals in special schools than in private and public clinical settings. Many professionals reported few barriers to the implementation of EBPs. These findings indicate conditions that are often conducive to the implementation of EBPs. However, these results do not reflect the situation in rural areas, in which poverty is more widespread and the number of specialized professionals is low.

Effectiveness of interventions for children and adolescents with autism spectrum disorder in high-income vs. lower middle-income countries: An overview of systematic reviews and research papers from LMIC

Background

There is a multitude of systematic reviews of interventions for children and adolescents with autism spectrum disorder (ASD). However, most reviews seem to be based on research conducted in High-Income Countries (HIC). Thus, summary findings may not directly apply to Lower Middle-Income Countries (LMIC). Therefore, we conducted a Meta-Review analyzing systematic reviews on the effectiveness of interventions for target outcomes in children and adolescents with ASD to find out whether there are differences in effectiveness between HIC and LMIC and which interventions can be considered evidence-based in LMIC.

Methods

Electronic databases (PsycINFO, PubMed, Cochrane database of systematic reviews) were searched for reviews on interventions for ASD in children and adolescents from January 2011 through December 2021, which included studies not coming from HIC. Systematic reviews with qualitative and quantitative syntheses of findings were included. Two investigators independently assessed studies against predetermined inclusion/exclusion criteria and extracted relevant data including quality and evidence assessments. Evidence for different types of interventions in HIC vs. LMIC was planned to be compared, but none of the reviews assessed potential differences. Therefore, a narrative review of the studies from LMIC was conducted including an assessment of quality and evidence.

Results

Thirty-five reviews fulfilled the inclusion criteria. Eleven considered findings from HIC and LMIC. Sixty-nine percent included studies with various research designs; 63% provided a qualitative synthesis of findings; 77% percent assessed the quality of studies; 43% systematically assessed the level of evidence across studies. No review compared evidence from HIC and LMIC. A review of the studies from LMIC found some promising results, but the evidence was not sufficient due to a small number of studies, sometimes poor quality, and small sample sizes.

Conclusion

Systematic reviews on interventions for children and adolescents with ASD did not look for potential differences in the effectiveness of interventions in HIC and LMIC. Overall, there is very little evidence from LMIC. None of the interventions can be considered evidence-based in LMIC. Hence, additional research and mutually agreed methodological standards are needed to provide a more secure basis for evidence-based treatments in LMIC trying to establish evidence-based practices.

Critical evaluation of contrasting evidence on whether male circumcision has adverse psychological effects: A systematic review

OBJECTIVE

To conduct the first systematic review critically examining evidence on whether early male circumcision has short- and long-term adverse psychological effects.

METHODS

We searched PubMed, EMBASE, SCOPUS, Cochrane Library, and Google Scholar.

RESULTS

Twenty-four studies with original data met the inclusion criteria. These comprised 11,173 total males, 4340 circumcised in infancy and 6908 uncircumcised. Nineteen were rated 1+, 2++ or 2+, and 5 were rated 2- by SIGN criteria. Neonatal circumcision, particularly without anesthetic, increased vaccination pain response, but had little effect on breastfeeding or cognitive ability. Studies reporting associations with sudden infant death syndrome, autism, alexithymia and impaired sexual function and pleasure had design flaws and were rated 2-. Sexual arousal, touch, pain, and warmth thresholds measured by quantitative sensory testing were not diminished in neonatally circumcised men. Neonatal circumcision was not associated with empathy in men, contradicting the hypothesis that procedural pain causes central nervous system changes. After correcting all associations with socioaffective processing parameters for multiple testing only higher sociosexual desire, dyadic sexual libido/drive, and stress remained significant. The relatively greater sexual activity found in circumcised men might reflect reduced sexual activity in uncircumcised men overall owing to pain and psychological aversion in those with foreskin-related medical conditions (reverse causality). Most studies employed case-control designs with limited follow-up. Studies beyond childhood were prone to confounding.

CONCLUSION

The highest quality evidence suggest that neonatal and later circumcision has limited or no short-term or long-term adverse psychological effects.

Effect of Care Coordination Using an Allied Health Liaison Officer for Chronic Noncomplex Medical Conditions in Children: A Multicenter Randomized Clinical Trial

IMPORTANCE

There is a paucity of high-quality evidence on the effect of care coordination on health-related quality of life among children with chronic noncomplex medical conditions (non-CMCs).

OBJECTIVE

To examine whether care coordination delivered by an Allied Health Liaison Officer results in improved quality-of-life (QOL) outcomes for children with chronic non-CMCs and their families.

DESIGN, SETTING AND PARTICIPANTS

This multicenter, open label, randomized clinical trial was conducted in pediatric outpatient clinics at 3 Australian hospitals with tertiary- and secondary-level pediatric care facilities. A total of 81 children with chronic non-CMCs and their families participated in the trial for a period of up to 12 months between October 2017 to October 2020. Primary care reviews were offered at 1 week, 3 months, and 6 months after diagnosis.

INTERVENTIONS

Eligible children were randomized 1:1 to receive care coordination or standard care. Families of children receiving care coordination were provided access to an Allied Health Liaison Officer, who was responsible for facilitation of health care access across hospital, education, primary care, and community sectors.

MAIN OUTCOMES AND MEASURES

The primary outcomes were scores on the Pediatric Quality of Life Inventory (PedsQL), version 4.0, and the PedsQL Family Impact Module, version 2.0, measured at 6 and 12 months. An intent-to-treat approach was used to analyze the data.

RESULTS

Of 81 children (mean [SD] age, 8.2 [3.5] years; 55 [67.9%] male), 42 (51.9%) were randomized to care coordination and 39 (48.1%) to standard care. Compared with standard care, care coordination resulted in greater improvements in overall PedsQL scores (difference in score changes between groups, 7.10; 95% CI, 0.44-13.76; P = .04), overall PedsQL Family Impact Module scores (difference in score changes between groups, 8.62; 95% CI, 1.07-16.16; P = .03), and family functioning QOL (difference in score changes between groups, 15.83; 95% CI, 5.05-26.62; P = .004) at 12 months after diagnosis.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, care coordination improved the quality of life of children with chronic non-CMCs and their families. Further studies should explore specific non-CMCs that may benefit most from care coordination and whether an orientation among health services to provide such a coordination model could lead to longer-term improved clinical outcomes.

TRIAL REGISTRATION

http://anzctr.org.au Identifier: ACTRN12617001188325.

The relationship between pesticide exposure during critical neurodevelopment and autism spectrum disorder: A narrative review

Agricultural pesticides have been one of the most extensively used compounds throughout the world. The main sources of contamination for humans are dietary intake and occupational exposure. The impairments caused by agricultural pesticide exposure have been a significant global public health problem. Recent studies have shown that low-level agricultural pesticide exposure during the critical period of neurodevelopment (pregnancy and lactation) is closely related to autism spectrum disorder (ASD). Inhibition of acetylcholinesterase, gut microbiota, neural dendrite morphology, synaptic function, and glial cells are targets for the effects of pesticides during nervous system development. In the present review, we summarize the associations between several highly used and frequently studied pesticides (e.g., glyphosate, chlorpyrifos, pyrethroids, and avermectins) and ASD. We also discusse future epidemiological and toxicological research directions on the relationship between pesticides and ASD.

Autism in Turkey: demographics, behavior problems, and accompanying medical conditions in a sample of Turkish youth with autism spectrum disorder

Autism spectrum disorder (ASD) is an etiologically heterogeneous neurodevelopmental condition that eludes a single explanation or cure. Epidemiological studies reveal risk factors, relevant comorbidities, and behavioral correlates to reach a better understanding of ASD. To contribute such data from an understudied ASD population, this paper presents epidemiological data from a Turkish sample of individuals with ASD (n = 911, 748 boys (82.1%) and 163 girls (17.9%) between 1 and 18 years of age). Average age at diagnosis was 31.06 ± 11.88 months, and the male-to-female ratio was 4.6:1. Three in 4 individuals with ASD had obsessive behaviors, and 1 in 4 had allergic conditions, inappropriate sexual behaviors, self-harming behaviors, and harmful behaviors towards others. One in 3 received a dietary treatment for at least 3 months; almost half received vitamin supplements; the majority (70%) did not experience constipation; and 2 in 3 were picky eaters. This paper presents data on the age of diagnosis, gender ratios, accompanying behaviors, and dietary interventions in Turkish individuals with ASD, which are topics of current research interest about ASD. Such data from non-Western populations may supplement epidemiological knowledge gained from Western populations to help reach a more comprehensive understanding of this condition with many unknowns.

Co-occurring hydrocephalus in autism spectrum disorder: a Danish population-based cohort study

Background

The association between autism spectrum disorder and hydrocephalus is not well understood, despite demonstrated links between autism spectrum disorder and cerebrospinal fluid abnormalities. Based on the hypothesis that autism spectrum disorder and hydrocephalus may, at least in some cases, be two manifestations of a shared congenital brain pathology, we investigated the potential association between autism spectrum disorder and hydrocephalus in a large Danish population-based cohort.

Methods

Patients and controls were obtained from the Lundbeck Foundation Initiative for Integrative Psychiatric Research iPSYCH2012 case-cohort, which includes all patients with selected psychiatric disorders born in Denmark 1981–2005 along with randomly selected population controls (end of follow-up, December 31, 2016). The associations between individual psychiatric disorders and hydrocephalus were estimated using binary logistic regression with adjustment for age and sex.

Results

The cohort consisted of 86,571 individuals, of which 14,654 were diagnosed with autism spectrum disorder, 28,606 were population controls, and the remaining were diagnosed with other psychiatric disorders. We identified 201 hydrocephalus cases; 68 among autism spectrum disorder patients and 40 among controls (OR 3.77, 95% CI 2.48–5.78), which corresponds to an absolute risk of 0.46 % (i.e. approximately one in 217 children with autism spectrum disorder had co-occurring hydrocephalus). The autism spectrum disorder-hydrocephalus association was significant over the entire subgroup spectrum of autism spectrum disorder.

Conclusions

Given the considerable risk of hydrocephalus among patients with autism spectrum disorder, we suggest that patients with autism spectrum disorder should be evaluated for co-occurring hydrocephalus on a routine basis as timely neurosurgical intervention is important. Likewise, attention must be paid to traits of autism spectrum disorder in children with hydrocephalus. The results of this study call for future investigations on a potential shared aetiology between hydrocephalus and autism spectrum disorder, including the role abnormal CSF dynamics in the pathogenesis of autism spectrum disorder.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11689-021-09367-0.

Hospital admissions in children with developmental disabilities from ethnic minority backgrounds

AIM

To compare hospital admission patterns after the first year of life in Australian children with developmental disabilities and children with no known disability, according to maternal country of birth and Indigenous status.

METHOD

This was a retrospective cohort study using linked data across health, disability, and hospital admission databases. The study investigated 656 174 children born in Western Australia between 1983 and 2008 with a total of 1 091 834 records of hospital admissions.

RESULTS

Children with no known disability born to Indigenous mothers had the highest rate of hospital admissions compared to children of non-Indigenous mothers. Children of foreign-born mothers from low-income countries had the highest rate of hospital admissions if disability was present. Children with cerebral palsy (CP) with or without associated intellectual disability had the highest rate of hospital admissions among children with developmental disability, especially if mothers were foreign-born.

INTERPRETATION

Children with CP and intellectual disability, particularly from minority backgrounds (Indigenous Australian and foreign-born mothers), were at higher risk of being admitted to hospital after the first year of life.

WHAT THIS PAPER ADDS

Hospital admissions in Australian children with and without disabilities differ according to maternal country of birth. Hospital admission rates in children without a developmental disability were greatest for Australian-born Indigenous children. Disabled Australian-born children of foreign-born mothers from low-income countries had the highest hospital admission rates. Hospital admission risk was greatest for Australian-born children with cerebral palsy, especially if mothers were foreign-born.

The Quality of Care for Australian Children with Autism Spectrum Disorders

Knowledge about the quality of care delivered to children with autism spectrum disorders (ASD) in relation to that recommended by clinical practice guidelines (CPGs) is limited. ASD care quality indicators were developed from CPGs and validated by experts, then used to assess the quality of care delivered by general practitioners (GPs) and pediatricians in Australia. Data were retrospectively collected from the medical records of 228 children (≤ 15 years) with ASD for 2012-2013. Overall quality of care was high, but with considerable variation among indicators, and between GPs and pediatricians-e.g., GPs were less likely to complete the assessment care bundle (61%; 95% CI 21-92). Findings highlight potential areas for improvement in the need for standardized criteria for diagnosis.

Improving Emotional Competence in Children With Autism Spectrum Disorder and Mild Intellectual Disability in Schools: A Preliminary Treatment Versus Waitlist Study

This pilot study evaluated the effectiveness of delivering a new cognitive behavioural intervention package ‘Emotion-Based Social Skills Training (EBSST) for Children with Autism Spectrum Disorder (ASD) and Mild Intellectual Disability (ASD + MID)’ in schools. Fourteen school counsellors nominated 75 children (aged 7–13 years) with ASD + MID to receive 16 sessions of EBSST in groups of 3–8 children in their schools. Parent and teacher pre-post ratings of emotional competence (Emotions Development Questionnaire), social skills (Social Skills Improvement System Rating Scales) and mental health (Developmental Behaviour Checklist) were collected. Forty-three children received 16 sessions of EBSST and 32 children were allocated to the 9-month waitlist control group. Teachers and parents also received six EBSST training sessions in separate groups at school. Significant improvements in parent and teacher ratings of emotional competence were found at posttreatment among children in the EBSST group relative to controls; however, the results were not significant after the Bonferroni adjustment. Small to medium effect sizes were found. No difference in untrained social skills or mental health was observed. This study provides preliminary support for the utility of EBSST in teaching emotional competence skills for children with ASD + MID in schools and provides valuable pilot data for future research.

The disparities of healthcare access for adults with autism spectrum disorder: Protocol for a systematic review

INTRODUCTION

Adults living with autism spectrum disorder (ASD) can experience many factors that may impact their everyday lives. Striving for optimal health and enduring a healthy lifestyle comes with the ability to access appropriate healthcare services, yet adults with ASD have unmet healthcare needs. The barriers and enablers of healthcare access for adults with ASD remain unclear. We will conduct a systematic review to explore what is currently known about healthcare access for adults with ASD, this will determine the level and appropriateness of access to healthcare services to better support the lives of adults with ASD.

METHOD AND ANALYSIS

The systematic review will report on all studies that include quantitative, qualitative, and mixed-methods designs that consider healthcare access for adults with ASD. We will search 5 databases: EBSCOhost, Scopus, PubMed, the Cochrane Library, and Web of Science. The Mixed Methods Appraisal Tool (MMAT) will be used to assess quality of articles and the Cochrane RoB 2.0 Tool will be used to assess for bias. Clarifying the evidence in this area will be important for future research directions when developing and piloting health interventions for researchers and healthcare clinicians in the field.

ETHICS AND DISSEMINATION

There are no human participants, data, or tissue being directly studied for the purposes of the review; therefore, ethics approval and consent to participate is not applicable.

REGISTRATION AND STATUS

PROSPERO 2018 CRD42018116093.

Risk of Developmental Disorders in Children of Immigrant Mothers: A Population-Based Data Linkage Evaluation

OBJECTIVES

To evaluate the prevalence and risks of developmental disability (autism spectrum disorder, intellectual disability, and cerebral palsy) in Western Australian children of different groups of foreign-born women.

STUDY DESIGN

Western Australian population-based linked data of 764 749 singleton live births from 1980 to 2010 were used to compare disability outcomes among children of foreign-born, Australian-born non-Indigenous, and Indigenous women. The risk of disability was assessed using multinomial logistic regression.

RESULTS

Overall, the prevalence of any disability was lowest for the children of foreign-born mothers. From 1980 to 1996 but not from 1997 to 2010, children born to mothers from foreign-born low-income countries had an increased relative risk of autism spectrum disorder with intellectual disability, and children born to foreign-born mothers from upper-middle-income countries had an increased risk of cerebral palsy with intellectual disability. After adjusting for smoking, the relative risks of intellectual disability and cerebral palsy with intellectual disability were markedly decreased in children of Australian-born Indigenous mothers.

CONCLUSIONS

Although we did not find among children born to foreign-born women an increased prevalence across all the measured developmental outcomes, we did observe an increased risk of autism spectrum disorder with intellectual disability and cerebral palsy with intellectual disability for mothers of some foreign-born groups. Our findings related to smoking in the Indigenous population underscore its possible role on the causal pathway to intellectual disability. Maternal migration is considered a factor on the causal pathway to intellectual disability. Maternal migration may be either a risk or a protective factor on the causal pathway to developmental disabilities and the direct role of migration is inconclusive in our study.

Prevalence of Autism Spectrum Disorder in a large Italian catchment area: a school-based population study within the ASDEU project

AIMS

This study aims to estimate Autism Spectrum Disorders (ASD) prevalence in school-aged children in the province of Pisa (Italy) using the strategy of the ASD in the European Union (ASDEU) project.

METHODS

A multistage approach was used to identify cases in a community sample (N = 10 138) of 7-9-year-old children attending elementary schools in Pisa - Italy. First, the number of children with a disability certificate was collected from the Local Health Authority and an ASD diagnosis was verified by the ASDEU team. Second, a Teacher Nomination form (TN) to identify children at risk for ASD was filled in by teachers who joined the study and the Social Communication Questionnaire (SCQ) was filled in by the parents of children identified as positive by the TN; a comprehensive assessment, which included the Autism Diagnostic Observation Schedule-Second Edition, was performed for children with positive TN and SCQ⩾9.

RESULTS

A total of 81 children who had a disability certificate also had ASD (prevalence: 0.79%, i.e. 1/126). Specifically, 66 children (57 males and nine females; 62% with intellectual disability -ID-) were certified with ASD, whereas another 15 (11 males and four females; 80% with ID) were recognised as having ASD among those certified with another neurodevelopmental disorder. Considering the population of 4417 (children belonging to schools which agreed to participate in the TN/SCQ procedure) and using only the number of children certified with ASD, the prevalence (38 in 4417) was 0.86%, i.e. one in 116. As far as this population is concerned, the prevalence rises to 1% if we consider the eight new cases (six males and two females; no subject had ID) identified among children with no pre-existing diagnoses and to 1.15%, i.e., one in 87, if probabilistic estimation is used.

CONCLUSIONS

This is the first population-based ASD prevalence study conducted in Italy so far and its results indicate a prevalence of ASD in children aged 7-9 years of about one in 87. This finding may help regional, national and international health planners to improve ASD policies for ASD children and their families in the public healthcare system.

Test of Gross Motor Development-3 (TGMD-3) with the Use of Visual Supports for Children with Autism Spectrum Disorder: Validity and Reliability

The validity and reliability of the Test of Gross Motor Development-3 (TGMD-3) were measured, taking into consideration the preference for visual learning of children with autism spectrum disorder (ASD). The TGMD-3 was administered to 14 children with ASD (4-10 years) and 21 age-matched typically developing children under two conditions: TGMD-3 traditional protocol, and TGMD-3 visual support protocol. Excellent levels of internal consistency, test-retest, interrater and intrarater reliability were achieved for the TGMD-3 visual support protocol. TGMD-3 raw scores of children with ASD were significantly lower than typically developing peers, however, significantly improved using the TGMD-3 visual support protocol. This demonstrates that the TGMD-3 visual support protocol is a valid and reliable assessment of gross motor performance for children with ASD.

General practice encounters for young patients with autism spectrum disorder in Australia

This study compared the patient demographics and reasons for encounter in general practice for patients <25 years with and without an autism spectrum disorder identified as a reason for encounter and/or problem managed. The Bettering the Evaluation and Care of Health programme collected information about clinical activities in Australian general practice. Each year, the programme recruited a random sample of 1000 general practitioners, each of whom collected data for 100 consecutive consultations (encounters). Encounters with patients <25 years, where at least one autism spectrum disorder was recorded as a reason for encounter and/or a problem managed (n = 579), were compared with all other encounters (n = 281,473) from April 2000 to March 2014 inclusive. Data were age–sex standardised. Patients at autism spectrum disorder encounters (compared to non-autism spectrum disorder encounters) were more likely to be younger and male. There was a dramatic rise in the number of general practitioner consultations at autism spectrum disorder encounters from 2000 to 2013. More reasons for encounter were recorded at autism spectrum disorder encounters than at non-autism spectrum disorder encounters (156.4 (95% confidence interval: 144.0–168.8) and 140.5 (95% confidence interval: 140.0–141.0), respectively). At autism spectrum disorder (vs non-autism spectrum disorder) encounters, there were more psychological, general and unspecified, and social reasons for encounter and fewer preventive and acute health reasons for encounter. People with an autism spectrum disorder have complex health care needs that require a skilled general practice workforce.

What Is the Male-to-Female Ratio in Autism Spectrum Disorder? A Systematic Review and Meta-Analysis

OBJECTIVE

To derive the first systematically calculated estimate of the relative proportion of boys and girls with autism spectrum disorder (ASD) through a meta-analysis of prevalence studies conducted since the introduction of the DSM-IV and the International Classification of Diseases, Tenth Revision.

METHOD

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. The Medline, Embase, and PsycINFO databases were searched, and study quality was rated using a risk-of-bias tool. Random-effects meta-analysis was used. The pooled outcome measurement was the male-to-female odds ratio (MFOR), namely the odds of being male in the group with ASD compared with the non-ASD group. In effect, this is the ASD male-to-female ratio, controlling for the male-to-female ratio among participants without ASD.

RESULTS

Fifty-four studies were analyzed, with 13,784,284 participants, of whom 53,712 had ASD (43,972 boys and 9,740 girls). The overall pooled MFOR was 4.20 (95% CI 3.84-4.60), but there was very substantial between-study variability (I² = 90.9%). High-quality studies had a lower MFOR (3.32; 95% CI 2.88-3.84). Studies that screened the general population to identify participants regardless of whether they already had an ASD diagnosis showed a lower MFOR (3.25; 95% CI 2.93-3.62) than studies that only ascertained participants with a pre-existing ASD diagnosis (MFOR 4.56; 95% CI 4.10-5.07).

CONCLUSION

Of children meeting criteria for ASD, the true male-to-female ratio is not 4:1, as is often assumed; rather, it is closer to 3:1. There appears to be a diagnostic gender bias, meaning that girls who meet criteria for ASD are at disproportionate risk of not receiving a clinical diagnosis.

Development of the Observable Behaviors of Autism Spectrum Disorder Scale

BACKGROUND

The objective of this research was to develop a caregiver-reported clinical outcome assessment (COA) measure designed to assess observable behaviors of children, ages 4 to 12 years, with autism spectrum disorder (ASD) for supporting labeling claims of treatment benefit.

METHODS

Development of the measure included a review of the literature and existing instruments, conceptual disease model development, concept elicitation focus groups, item generation, and cognitive debriefing interviews.

RESULTS

Predominant characteristics and behaviors of ASD identified by the literature and instrument reviews included sociability, communication deficits, stereotypy, inattention and hyperactivity, irritability, anxiety, and familial impact. In each of the 10 instruments reviewed, evidence of content validity was limited or nonexistent. Predominant themes arose across 8 major categories during concept elicitation. A total of 27 concepts were identified through focus group feedback and formed the basis for item development and cognitive pre-testing. Revisions to the items yielded a final version of a daily diary containing 21 items assessing observable behaviors and characteristics of ASD in children 4 to 12 years old.

CONCLUSIONS

The Observable Behaviors of ASD Scale (OBAS) was developed as a self-administered, caregiver-reported measure containing 8 predominant themes. Items are scored on one of two 5-point ordinal categorical response scales, and the recall period for each item is "the past 24 hours." This research provides evidence that the OBAS is content valid for assessing treatment benefit, which was found to be lacking in other instruments.

If genetic variation could talk: What genomic data may teach us about the importance of gene expression regulation in the genetics of autism

Autism spectrum disorder (ASD) has been long known to have substantial genetic etiology. Much research has attempted to identify specific genes contributing to ASD risk with the goal of tying gene function to a molecular pathological explanation for ASD. A unifying molecular pathology would potentially increase understanding of what is going wrong during development, and could lead to diagnostic biomarkers or targeted preventative or therapeutic directions. We review past and current genetic mapping approaches and discuss major results, leading to the hypothesis that global dysregulation of gene or protein expression may be implicated in ASD rather than disturbance of brain-specific functions. If substantiated, this hypothesis might indicate the need for novel experimental and analytical approaches in order to understand this neurodevelopmental disorder, develop biomarkers, or consider treatment approaches.

Randomised controlled trial of an iPad based early intervention for autism: TOBY playpad study protocol

BACKGROUND

Evidence for early intensive behavioural interventions (EIBI) by therapists as an effective treatment for children with an Autism Spectrum Disorder (ASD) is growing. High-intensity and sustained delivery of quality EIBI is expensive. The TOBY (Therapy Outcomes by You) Playpad is an App-based platform delivering EIBI to facilitate learning for young children with ASD, while enabling parents to become co-therapists. Intervention targets include increasing joint attention, imitation and communication of children with ASD. The primary aim of the study presented in this protocol is to determine the effectiveness of the TOBY App in reducing ASD symptoms when used as a complement to conventional EIBI. The secondary aim is to examine parental attributes as a result of TOBY App use.

METHODS AND DESIGN

Children aged less than 4;3 years diagnosed with ASD and parents will be recruited into this single-blind, randomised controlled trial using a pragmatic approach. Eligible participants will be randomised to the treatment group 'TOBY therapy + therapy as usual' or, the control group 'therapy as usual' for six months. The treatment will be provided by the TOBY App and parent where a combination of learning environments such as on-iPad child only (solo), partner (with parent) and off-iPad - Natural Environment (with parent) Tasks will be implemented. Parents in the treatment group will participate in a TOBY training workshop. Treatment fidelity will be monitored via an App-based reporting system and parent diaries. The primary outcome measure is the Autism Treatment Evaluation Checklist. The secondary outcome measures involve diagnostics, functional and developmental assessments, including parent questionnaires at baseline (T0), three months (T1) and six months (T2).

DISCUSSION

This trial will determine the effectiveness of the TOBY App as a therapeutic complement to other early interventions children with ASD receive. The trial will also determine the feasibility of a parent delivered early intervention using the iPad as an educational platform, and assess the impact of the TOBY App on parents' self-efficacy and empowerment in an effort to reduce children's ASD symptoms. The outcomes of this trial may have EIBI services implications for newly diagnosed children with ASD and parents.

TRIAL REGISTRATION

ACTRN12614000738628 retrospectively registered on 1st of July, 2014. UTN: U1111-1158-6423.

Autism spectrum disorder reporting in lower socioeconomic neighborhoods

Utilizing surveillance data from five sites participating in the Autism and Developmental Disabilities Monitoring Network, we investigated contributions of surveillance subject and census tract population sociodemographic characteristics on variation in autism spectrum disorder ascertainment and prevalence estimates from 2000 to 2008 using ordinal hierarchical models for 2489 tracts. Multivariable analyses showed a significant increase in ascertainment of autism spectrum disorder cases through both school and health sources, the optimal ascertainment scenario, for cases with college-educated mothers (adjusted odds ratio = 1.06, 95% confidence interval = 1.02–1.09). Results from our examination of sociodemographic factors of tract populations from which cases were drawn also showed that after controlling for other covariates, statistical significance remained for associations between optimal ascertainment and percentage of Hispanic residents (adjusted odds ratio = 0.93, 95% confidence interval = 0.88–0.99) and percentage of residents with at least a bachelor’s degree (adjusted odds ratio = 1.06, 95% confidence interval = 1.01–1.11). We identified sociodemographic factors associated with autism spectrum disorder prevalence estimates including race, ethnicity, education, and income. Determining which specific factors influence disparities is complicated; however, it appears that even in the presence of education, racial and ethnic disparities are still apparent. These results suggest disparities in access to autism spectrum disorder assessments and special education for autism spectrum disorder among ethnic groups may impact subsequent surveillance.

Hypothesis on supine sleep, sudden infant death syndrome reduction and association with increasing autism incidence

AIM: To identify a hypothesis on: Supine sleep, sudden infant death syndrome (SIDS) reduction and association with increasing autism incidence.

METHODS: Literature was searched for autism spectrum disorder incidence time trends, with correlation of change-points matching supine sleep campaigns. A mechanistic model expanding the hypothesis was constructed based on further review of epidemiological and other literature on autism.

RESULTS: In five countries (Denmark, United Kingdom, Australia, Israel, United States) with published time trends of autism, change-points coinciding with supine sleep campaigns were identified. The model proposes that supine sleep does not directly cause autism, but increases the likelihood of expression of a subset of autistic criteria in individuals with genetic susceptibility, thereby specifically increasing the incidence of autism without intellectual disability.

CONCLUSION: Supine sleep is likely a physiological stressor, that does reduce SIDS, but at the cost of impact on emotional and social development in the population, a portion of which will be susceptible to, and consequently express autism. A re-evaluation of all benefits and harms of supine sleep is warranted. If the SIDS mechanism proposed and autism model presented can be verified, the research agenda may be better directed, in order to further decrease SIDS, and reduce autism incidence.

Building Language Resources for Exploring Autism Spectrum Disorders

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that would benefit from low-cost and reliable improvements to screening and diagnosis. Human language technologies (HLTs) provide one possible route to automating a series of subjective decisions that currently inform "Gold Standard" diagnosis based on clinical judgment. In this paper, we describe a new resource to support this goal, comprised of 100 20-minute semi-structured English language samples labeled with child age, sex, IQ, autism symptom severity, and diagnostic classification. We assess the feasibility of digitizing and processing sensitive clinical samples for data sharing, and identify areas of difficulty. Using the methods described here, we propose to join forces with researchers and clinicians throughout the world to establish an international repository of annotated language samples from individuals with ASD and related disorders. This project has the potential to improve the lives of individuals with ASD and their families by identifying linguistic features that could improve remote screening, inform personalized intervention, and promote advancements in clinically-oriented HLTs.

Prenatal Neurogenesis in Autism Spectrum Disorders

An ever-increasing body of literature describes compelling evidence that a subset of young children on the autism spectrum show abnormal cerebral growth trajectories. In these cases, normal cerebral size at birth is followed by a period of abnormal growth and starting in late childhood often by regression compared to unaffected controls. Recent work has demonstrated an abnormal increase in the number of neurons of the prefrontal cortex suggesting that cerebral size increase in autism is driven by excess neuronal production. In addition, some affected children display patches of abnormal laminar positioning of cortical projection neurons. As both cortical projection neuron numbers and their correct layering within the developing cortex requires the undisturbed proliferation of neural progenitors, it appears that neural progenitors lie in the center of the autism pathology associated with early brain overgrowth. Consequently, autism spectrum disorders associated with cerebral enlargement should be viewed as birth defects of an early embryonic origin with profound implications for their early diagnosis, preventive strategies, and therapeutic intervention.

Changes in prevalence of autism spectrum disorders in 2001-2011: findings from the Stockholm youth cohort

In a record-linkage study in Stockholm, Sweden, the year 2011 prevalence of diagnosed autism spectrum disorders (ASD) was found to be 0.40, 1.74, 2.46, and 1.76% among 0-5, 6-12, 13-17, and 18-27 year olds, respectively. The corresponding proportion of cases with a recorded diagnosis of intellectual disability was 17.4, 22.1, 26.1 and 29.4%. Between 2001 and 2011, ASD prevalence increased almost 3.5 fold among children aged 2-17 years. The increase was mainly accounted for by an eightfold increase of ASD without intellectual disability (from 0.14 to 1.10 %), while the prevalence of ASD with intellectual disability increased only slightly (from 0.28 to 0.34%). The increase in ASD prevalence is likely contributed to by extrinsic factors such as increased awareness and diagnostics.

Urbanicity and autism spectrum disorders

The etiology of autism spectrum disorders (ASD) is for the majority of cases unknown and more studies of risk factors are needed. Geographic variation in ASD occurrence has been observed, and urban residence has been suggested to serve as a proxy for etiologic and identification factors in ASD. We examined the association between urbanicity level and ASD at birth and during childhood. The study used a Danish register-based cohort of more than 800,000 children of which nearly 4,000 children were diagnosed with ASD. We found a dose-response association with greater level of urbanicity and risk of ASD. This association was found for residence at birth as well as residence during childhood. Further, we found an increased risk of ASD in children who moved to a higher level of urbanicity after birth. Also, earlier age of ASD diagnosis in urban areas was observed. While we could not directly examine the specific reasons behind these associations, our results demonstrating particularly strong associations between ASD diagnosis and post-birth migration suggest the influence of identification-related factors such as access to services might have a substantive role on the ASD differentials we observed.

Impact of adherence to best practice guidelines on the diagnostic and assessment services for autism spectrum disorder

Despite their range and complexity, adherence to Scottish Intercollegiate Guidelines Network guideline for the diagnosis and assessment of autism spectrum disorders (ASD) was shown to be high within child development and specialist diagnostic clinics serving a geographical cohort of children diagnosed under the age of 7 years. A retrospective analysis of comprehensive clinical notes demonstrated that the recommended discretionary use of structured history instruments was increased after medical training (p = 0.003). 56% (51/90) of children received the diagnosis of ASD at their initial specialist appointment. 51% underwent the recommended discretionary structured observational instrument. This further assessment was more likely to be required for older children in the reaudited group (p = 0.001). The implications for service capacity planning when delivering best practice recommendations are discussed.

Potential impact of DSM-5 criteria on autism spectrum disorder prevalence estimates

IMPORTANCE

The DSM-5 contains revised diagnostic criteria for autism spectrum disorder (ASD) from the DSM-IV-TR. Potential impacts of the new criteria on ASD prevalence are unclear.

OBJECTIVE

To assess potential effects of the DSM-5 ASD criteria on ASD prevalence estimation by retrospectively applying the new criteria to population-based surveillance data collected for previous ASD prevalence estimation.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional, population-based ASD surveillance based on clinician review of coded behaviors documented in children's medical and educational evaluations from 14 geographically defined areas in the United States participating in the Autism and Developmental Disabilities Monitoring (ADDM) Network in 2006 and 2008. This study included 8-year-old children living in ADDM Network study areas in 2006 or 2008, including 644 883 children under surveillance, of whom 6577 met surveillance ASD case status based on the DSM-IV-TR.

MAIN OUTCOMES AND MEASURES

Proportion of children meeting ADDM Network ASD criteria based on the DSM-IV-TR who also met DSM-5 criteria; overall prevalence of ASD using DSM-5 criteria.

RESULTS

Among the 6577 children classified by the ADDM Network as having ASD based on the DSM-IV-TR, 5339 (81.2%) met DSM-5 ASD criteria. This percentage was similar for boys and girls but higher for those with than without intellectual disability (86.6% and 72.5%, respectively; P < .001). A total of 304 children met DSM-5 ASD criteria but not current ADDM Network ASD case status. Based on these findings, ASD prevalence per 1000 for 2008 would have been 10.0 (95% CI, 9.6-10.3) using DSM-5 criteria compared with the reported prevalence based on DSM-IV-TR criteria of 11.3 (95% CI, 11.0-11.7).

CONCLUSIONS AND RELEVANCE

Autism spectrum disorder prevalence estimates will likely be lower under DSM-5 than under DSM-IV-TR diagnostic criteria, although this effect could be tempered by future adaptation of diagnostic practices and documentation of behaviors to fit the new criteria.

Use of selective serotonin reuptake inhibitors during pregnancy and risk of autism

BACKGROUND

Studies have raised concern about an association between the use of selective serotonin reuptake inhibitors (SSRIs) during pregnancy and an increased risk of autism spectrum disorders in the offspring.

METHODS

We conducted a cohort study of all singleton live births in Denmark from 1996 through 2005 (626,875 births), with follow-up through 2009. Using Danish population registries, we linked information on maternal use of SSRIs before and during pregnancy, autism spectrum disorders diagnosed in the offspring, and a range of potential confounders. We used a survival analysis of the time to diagnosis in the offspring with Poisson regression to estimate rate ratios of autism spectrum disorders according to maternal use of SSRIs.

RESULTS

During 5,057,282 person-years of follow-up, we identified 3892 cases of autism spectrum disorder (incidence rate, 77.0 per 100,000 person-years). A total of 52 cases during 42,400 person-years of follow-up involved offspring of women who were exposed to SSRIs during their pregnancy (incidence rate, 122.6 per 100,000 person-years). As compared with no use of SSRIs both before and during pregnancy, use during pregnancy was not associated with a significantly increased risk of autism spectrum disorders (fully adjusted rate ratio, 1.20; 95% confidence interval [CI], 0.90 to 1.61). Among women who received SSRIs before pregnancy but not during pregnancy, the corresponding fully adjusted rate ratio was 1.46 (95% CI, 1.17 to 1.81).

CONCLUSIONS

We did not detect a significant association between maternal use of SSRIs during pregnancy and autism spectrum disorder in the offspring. On the basis of the upper boundary of the confidence interval, our study could not rule out a relative risk up to 1.61, and therefore the association warrants further study. (Funded by the Danish Health and Medicines Authority.).

Prenatal and perinatal analgesic exposure and autism: an ecological link

BACKGROUND

Autism and Autism Spectrum Disorder (ASD) are complex neurodevelopmental disorders. Susceptibility is believed to be the interaction of genetic heritability and environmental factors. The synchronous rises in autism/ASD prevalence and paracetamol (acetaminophen) use, as well as biologic plausibility have led to the hypothesis that paracetamol exposure may increase autism/ASD risk.

METHODS

To explore the relationship of antenatal paracetamol exposure to ASD, population weighted average autism prevalence rates and paracetamol usage rates were compared. To explore the relationship of early neonatal paracetamol exposure to autism/ASD, population weighted average male autism prevalence rates for all available countries and U.S. states were compared to male circumcision rates - a procedure for which paracetamol has been widely prescribed since the mid-1990s. Prevalence studies were extracted from the U.S. Centers for Disease Control and Prevention Summary of Autism/ASD Prevalence Studies database. Maternal paracetamol usage and circumcision rates were identified by searches on Pub Med.

RESULTS

Using all available country-level data (n = 8) for the period 1984 to 2005, prenatal use of paracetamol was correlated with autism/ASD prevalence (r = 0.80). For studies including boys born after 1995, there was a strong correlation between country-level (n = 9) autism/ASD prevalence in males and a country's circumcision rate (r = 0.98). A very similar pattern was seen among U.S. states and when comparing the 3 main racial/ethnic groups in the U.S. The country-level correlation between autism/ASD prevalence in males and paracetamol was considerably weaker before 1995 when the drug became widely used during circumcision.

CONCLUSIONS

This ecological analysis identified country-level correlations between indicators of prenatal and perinatal paracetamol exposure and autism/ASD. State level correlation was also identified for the indicator of perinatal paracetamol exposure and autism/ASD. Like all ecological analyses, these data cannot provide strong evidence of causality. However, biologic plausibility is provided by a growing body of experimental and clinical evidence linking paracetamol metabolism to pathways shown to be important in autism and related developmental abnormalities. Taken together, these ecological findings and mechanistic evidence suggest the need for formal study of the role of paracetamol in autism.

Autism spectrum disorders in the Stockholm Youth Cohort: design, prevalence and validity

OBJECTIVE

Reports of rising prevalence of autism spectrum disorders (ASD), along with their profound personal and societal burden, emphasize the need of methodologically sound studies to explore their causes and consequences. We here present the design of a large intergenerational resource for ASD research, along with population-based prevalence estimates of ASD and their diagnostic validity.

METHOD

The Stockholm Youth Cohort is a record-linkage study comprising all individuals aged 0-17 years, ever resident in Stockholm County in 2001-2007 (N = 589,114). ASD cases (N = 5,100) were identified using a multisource approach, involving registers covering all pathways to ASD diagnosis and care, and categorized according to co-morbid intellectual disability. Prospectively recorded information on potential determinants and consequences of ASD were retrieved from national and regional health and administrative registers. Case ascertainment was validated through case-note review, and cross validation with co-existing cases in a national twin study.

RESULTS

The 2007 year prevalence of ASD in all children and young people was 11.5 per 1,000 (95% confidence interval 11.2-11.8), with a co-morbid intellectual disability recorded in 42.6% (41.0-44.2) of cases. We found 96.0% (92.0-98.4) of reviewed case-notes being consistent with a diagnosis of ASD, and confirmed ASD in 85.2% (66.2-95.8) of affected twins.

CONCLUSIONS

Findings from this contemporary study accords with recently reported prevalence estimates from Western countries at around 1%, based on valid case ascertainment. The Stockholm Youth Cohort, in light of the availability of extensive information from Sweden's registers, constitutes an important resource for ASD research. On-going work, including collection of biological samples, will enrich the study further.