Advancing early detection of autism spectrum disorder by applying an integrated two-stage screening approach

Network Structure of Autism Spectrum Disorder Behaviors and Its Evolution in Preschool Children: Insights from a New Longitudinal Network Analysis Method

Network modeling of the social, communication and restrictive/repetitive behaviors (RRBs) included in the definition of Autism Spectrum Disorder was performed. The Autism Diagnostic Interview-Revised (ADI-R) assessed behaviors in 139 pre-school cases at two cross-sections that averaged 34.8 months apart. Cross-sectional networks were based on the correlation matrix of the ADI-R behavioral items and the "bootCross" method was developed and enabled the estimation of a longitudinal network. At both stages, RRB items/nodes formed a consistent peripheral cluster, while social and communication nodes formed a core cluster that diverged with time. These differences in the nature and evolution of the RRB and socio-communicative dimensions indicate that their inter-behavior dynamics are very different. The most central behaviors across stages are proposed as prime targets for efficient therapeutic intervention.

Early Identification of Autism Spectrum Disorder (ASD): Strategies for Use in Local Communities

Early diagnosis of autism spectrum disorder (ASD) is essential for improved outcomes. There is a paucity of data on the prevalence of ASD in low- and middle-income countries (LMIC), but early identification may be further delayed in those communities. In this paper, recent studies on strategies for the early detection of ASD, and the prevalence of ASD in LMIC are reviewed. The limitations that can arise in the early identification of ASD in LMIC communities are discussed, and screening tools and strategies that can be helpful are identified. The goal is to recommend models that are culturally appropriate and scientifically valid, easily integrated within community settings while strengthening community systems and reducing disparities in the early identification of ASD. Starting locally by simplifying and demystifying the ASD identification process and building community connections will inform global researchers and policymakers while making a difference in the lives of the children and families affected by ASD.

Empirical Study of Autism Spectrum Disorder Diagnosis Using Facial Images by Improved Transfer Learning Approach

Autism spectrum disorder (ASD) is a neurological illness characterized by deficits in cognition, physical activities, and social skills. There is no specific medication to treat this illness; only early intervention can improve brain functionality. Since there is no medical test to identify ASD, a diagnosis might be challenging. In order to determine a diagnosis, doctors consider the child's behavior and developmental history. The human face can be used as a biomarker as it is one of the potential reflections of the brain and thus can be used as a simple and handy tool for early diagnosis. This study uses several deep convolutional neural network (CNN)-based transfer learning approaches to detect autistic children using the facial image. An empirical study is conducted to select the best optimizer and set of hyperparameters to achieve better prediction accuracy using the CNN model. After training and validating with the optimized setting, the modified Xception model demonstrates the best performance by achieving an accuracy of 95% on the test set, whereas the VGG19, ResNet50V2, MobileNetV2, and EfficientNetB0 achieved 86.5%, 94%, 92%, and 85.8%, accuracy, respectively. Our preliminary computational results demonstrate that our transfer learning approaches outperformed existing methods. Our modified model can be employed to assist doctors and practitioners in validating their initial screening to detect children with ASD disease.

[Early prognostic of ASD: A challenge]

Autism Spectrum Disorders (ASD) are born in the womb generated by intrauterine genetic or environmental insult. ASD diagnostic is made at the age of 3-5 years in Europe and in the US. Relying on this, we have tested the hypothesis of identifying already at birth babies who might be diagnosed later with ASD, thereby facilitating an early use of psychoeducative techniques to attenuate the severity of the symptoms. Here, we discuss the various approaches that have been used to enable an early diagnosis. We have ourselves used an approach based on a "without a priori" machine learning analysis of all maternity biological and ultrasound data available in French maternities (around 116) in utero and after birth. This program made it possible to identify at birth almost all (96%) of babies who will be later neurotypical and around half of those who will be diagnosed with ASD. Some of the parameters allowing this identification were largely unexpected with no known links with ASD. This approach will enable an early identification of babies at risk, but also might be used to diagnose ASD later on, and perhaps could help to get a better understanding of the heterogeneity of ASD.

Is the Combination of ADOS and ADI-R Necessary to Classify ASD? Rethinking the "Gold Standard" in Diagnosing ASD

Diagnosing autism spectrum disorder (ASD) requires extensive clinical expertise and training as well as a focus on differential diagnoses. The diagnostic process is particularly complex given symptom overlap with other mental disorders and high rates of co-occurring physical and mental health concerns. The aim of this study was to conduct a data-driven selection of the most relevant diagnostic information collected from a behavior observation and an anamnestic interview in two clinical samples of children/younger adolescents and adolescents/adults with suspected ASD. Via random forests, the present study discovered patterns of symptoms in the diagnostic data of 2310 participants (46% ASD, 54% non-ASD, age range 4-72 years) using data from the combined Autism Diagnostic Observation Schedule (ADOS) and Autism Diagnostic Interview-Revised (ADI-R) and ADOS data alone. Classifiers built on reduced subsets of diagnostic features yield satisfactory sensitivity and specificity values. For adolescents/adults specificity values were lower compared to those for children/younger adolescents. The models including ADOS and ADI-R data were mainly built on ADOS items and in the adolescent/adult sample the classifier including only ADOS items performed even better than the classifier including information from both instruments. Results suggest that reduced subsets of ADOS and ADI-R items may suffice to effectively differentiate ASD from other mental disorders. The imbalance of ADOS and ADI-R items included in the models leads to the assumption that, particularly in adolescents and adults, the ADI-R may play a lesser role than current behavior observations.

Validation of the Modified Checklist for Autism in Toddlers, Revised with Follow-up in a Population Sample of 30-Month-Old Children in Iceland: A Prospective Approach

The Modified Checklist for Autism in Toddlers, Revised with Follow-up was validated on a population sample in Reykjavik, Iceland. The participants (N = 1585) were screened in well-child care at age 30 months and followed up for at least 2 years to identify autism cases. The sensitivity, specificity, positive and negative predictive values were 0.62, 0.99, 0.72, and 0.99, respectively. True-positive children were diagnosed 10 months earlier than false-negative children. Autism symptom severity and the proportions of children with verbal and performance IQs/DQs < 70 were similar between groups. Although the sensitivity was suboptimal, the screening contributed to lowering the age at diagnosis for many children. Adding autism-specific screening to the well-child care program should be considered.

Autism Spectrum Disorder Alertness in Dutch Youth and Family Center Physicians: Effects of a Live Online Educational Program

We investigated the effect of a live online educational program in 93 Dutch Youth and Family Center (YFC) physicians who were screening for Autism Spectrum Disorder (ASD) in the general child population. The educational program raised the physicians' level of specific ASD knowledge and it remained higher at six months follow-up (p < .01). Their self-confidence in detecting ASD was also higher and maintained at follow-up (p < .01). The educational program had no effect on the physicians' stigmatizing attitudes toward mental illness nor on the number of potential ASD referrals in children of 4-6 years of age. In conclusion, the online educational program on early detection of ASD has a six month long effect on YFC physicians' level of ASD knowledge and self-confidence.

Improving Early Identification and Access to Diagnosis of Autism Spectrum Disorder in Toddlers in a Culturally Diverse Community with the Rapid Interactive screening Test for Autism in Toddlers

The objective of this study was to test a screening model that employs the Rapid Interactive Screening Test for Autism in Toddlers (RITA-T), in an underserved community to improve ASD detection. We collaborated with a large Early Intervention (EI) program and trained 4 providers reliably on the RITA-T. Toddlers received the Modified Checklist for Autism in Toddlers (MCHAT-R/F), the RITA-T, developmental and autism testing, and a best-estimate clinical diagnosis. Eighty-One toddlers were enrolled: 57 with ASD and 24 with Developmental Delay (DD) non-ASD. Wait-time for diagnosis was on average 6 weeks. The RITA-T correlated highly with autism measures and EI staff integrated this model easily. The RITA-T significantly improved the identification and wait time for ASD in this underserved community.

Autism Screening in Early Childhood: Discriminating Autism From Other Developmental Concerns

Early identification of autism, followed by appropriate intervention, has the potential to improve outcomes for autistic individuals. Numerous screening instruments have been developed for children under 3 years of age. Level 1 screeners are used in large-scale screening to detect at-risk children in the general population; Level 2 screeners are concerned with distinguishing children with signs of autism from those with other developmental problems. The focus here is evaluation of Level 2 screeners. However, given the contributions of Level 1 screeners and the necessity to understand how they might interface with Level 2 screeners, we briefly review Level 1 screeners and consider instrument characteristics and system variables that may constrain their effectiveness. The examination of Level 2 screeners focuses on five instruments associated with published evaluations in peer-reviewed journals. Key criteria encompass the traditional indices of test integrity such as test reliability (inter-rater, test-retest) and construct validity, including concurrent and predictive validity, sensitivity (SE), and specificity (SP). These evaluations reveal limitations, including inadequate sample sizes, reliability issues, and limited involvement of independent researchers. Also lacking are comparative test evaluations under standardized conditions, hindering interpretation of differences in discriminative performance across instruments. Practical considerations constraining the use of such instruments—such as the requirements for training in test administration and test administration time—are canvassed. Published Level 2 screener short forms are reviewed and, as a consequence of that evaluation, future directions for assessing the discriminative capacity of items and measures are suggested. Suggested priorities for future research include targeting large and diverse samples to permit robust appraisals of Level 2 items and scales across the 12–36 month age range, a greater focus on precise operationalization of items and response coding to enhance reliability, ongoing exploration of potentially discriminating items at the younger end of the targeted age range, and trying to unravel the complexities of developmental trajectories in autistic infants. Finally, we emphasize the importance of understanding how screening efficacy is dependent on clinicians' and researchers' ability not only to develop screening tests but also to negotiate the complex organizational systems within which screening procedures must be implemented.

Novel Insights into Autism Knowledge and Stigmatizing Attitudes Toward Mental Illness in Dutch Youth and Family Center Physicians

Professionals' limited knowledge on mental health and their stigmatizing attitudes toward mental illness can delay the diagnosis of autism. We evaluated the knowledge on Autism Spectrum Disorder (ASD) and stigmatizing attitudes in 93 physicians at Dutch Youth and Family Centers (YFC). These physicians screen for psychiatric symptoms in children. We show that their general ASD knowledge scored 7.1 (SD 1.2), but their specific ASD knowledge was only 5.7 (SD 1.7) (weighted means on 1-10 scale, 1 = least knowledge, 10 = most knowledge). Our physicians had positive attitudes toward mental illness (CAMI scores 2.18 (SD 0.33) to 2.22 (SD 0.40) on a 5-point Likert scale) but they had higher levels of stigmatizing attitudes than other Western healthcare professionals. Their levels were considerably lower than in non-Western professionals. We found no relations between ASD knowledge, stigmatizing attitudes and demographic variables. In conclusion, ASD knowledge and stigmatizing attitudes toward mental illness in Dutch YFC physicians require attention.

Linking risk factors and outcomes in autism spectrum disorder: is there evidence for resilience?

Autism spectrum disorder (referred to here as autism) is one of several overlapping neurodevelopmental conditions that have variable impacts on different individuals. This variability results from dynamic interactions between biological and non-biological risk factors, which result in increasing differentiation between individuals over time. Although this differentiation continues well into adulthood, the infancy period is when the brain and behavior develop rapidly, and when the first signs and symptoms of autism emerge. This review discusses advances in our understanding of the causal pathways leading to autism and overlapping neurodevelopmental conditions. Research is also mapping trajectories of brain and behavioral development for some risk groups, namely later born siblings of children with autism and/or infants referred because of developmental concerns. This knowledge has been useful in improving early identification and establishing the feasibility of targeted interventions for infant risk groups before symptoms arise. However, key knowledge gaps remain, such as the discovery of protective factors (biological or environmental) that may mitigate the impact of risk. Also, the dynamic mechanisms that underlie the associations between risk factors and outcomes need further research. These include the processes of resilience, which may explain why some individuals at risk for autism achieve better than expected outcomes. Bridging these knowledge gaps would help to provide tools for early identification and intervention that reflect dynamic developmental pathways from risk to outcomes.

Le dépistage précoce du trouble du spectre de l’autisme chez les jeunes enfants

Le trouble du spectre de l’autisme (TSA) est un trouble neurodéveloppemental permanent qui se caractérise par des déficits de la communication sociale, un mode répétitif et restreint des comportements et des sensibilités ou des intérêts sensoriels inhabituels. Le TSA a des répercussions importantes sur la vie des enfants et de leur famille. À l’heure actuelle, sa prévalence estimative est de un cas sur 66 enfants et adolescents canadiens dans le groupe d’âge des cinq à 17 ans. Les pédiatres généraux, les médecins de famille et les autres professionnels de la santé rencontrent donc plus d’enfants ayant un TSA qu’auparavant dans leur pratique. Le diagnostic rapide de ce trouble et l’orientation des cas vers des interventions comportementales et éducationnelles intensives dès le plus jeune âge peuvent favoriser un meilleur pronostic clinique à long terme grâce à la neuroplasticité du cerveau à un plus jeune âge. Le présent docu-ment de principes contient des recommandations et des outils clairs, détaillés et fondés sur des données probantes pour aider les pédiatres communautaires et les autres dispensateurs de soins de première ligne à surveiller les tout premiers signes de TSA, ce qui constitue une étape importante vers un diagnostic précis et une évaluation détaillée des besoins pour planifier les interventions.

Early detection for autism spectrum disorder in young children

Autism spectrum disorder (ASD) is a life-long neurodevelopmental disorder, characterized by impairments in social communication, repetitive, restricted patterns of behaviour, and unusual sensory sensitivities or interests. ASD significantly impacts the lives of children and their families. Currently, the estimated prevalence of ASD is 1 in 66 Canadians aged 5 to 17 years. General paediatricians, family physicians, and other health care professionals are, therefore, seeing more children with ASD in their practices. The timely diagnosis of ASD, and referral for intensive behavioural and educational interventions at the earliest age possible, may lead to better long-term outcomes by capitalizing on the brain's neuroplasticity at younger ages. This statement provides clear, comprehensive, evidence-informed recommendations and tools to help community paediatricians and other primary care providers monitor for the earliest signs of ASD-an important step toward an accurate diagnosis and comprehensive needs assessment for intervention planning.

Screening for Autism with the SRS and SCQ: Variations across Demographic, Developmental and Behavioral Factors in Preschool Children

The Social Communication Questionnaire (SCQ) and the Social Responsiveness Scales (SRS) are commonly used screeners for autism spectrum disorder (ASD). Data from the Study to Explore Early Development were used to examine variations in the performance of these instruments by child characteristics and family demographics. For both instruments, specificity decreased as maternal education and family income decreased. Specificity was decreased with lower developmental functioning and higher behavior problems. This suggests that the false positive rates of the SRS and the SCQ are associated with child characteristics and family demographic factors. There is a need for ASD screeners that perform well across socioeconomic and child characteristics. Clinicians should be mindful of differential performance of these instruments in various groups of children.

Infant and dyadic assessment in early community-based screening for autism spectrum disorder with the PREAUT grid

Background

The need for early treatment of autism spectrum disorders (ASD) necessitates early screening. Very few tools have been prospectively tested with infants of less than 12 months of age. The PREAUT grid is based on dyadic assessment through interaction and shared emotion and showed good metrics for predicting ASD in very-high-risk infants with West syndrome.

Methods

We assessed the ability of the PREAUT grid to predict ASD in low-risk individuals by prospectively following and screening 12,179 infants with the PREAUT grid at four (PREAUT-4) and nine (PREAUT-9) months of age. A sample of 4,835 toddlers completed the Checklist for Autism in Toddlers (CHAT) at 24 months (CHAT-24) of age. Children who were positive at one screening (N = 100) were proposed a clinical assessment (including the Children Autism Rating Scale, a Developmental Quotient, and an ICD-10-based clinical diagnosis if appropriate) in the third year of life. A randomly selected sample of 1,100 individuals who were negative at all screenings was followed by the PMI team from three to five years of age to identify prospective false negative cases. The clinical outcome was available for 45% (N = 45) of positive children and 52.6% (N = 579) of negative children.

Results

Of the 100 children who screened positive, 45 received a diagnosis at follow-up. Among those receiving a diagnosis, 22 were healthy, 10 were diagnosed with ASD, seven with intellectual disability (ID), and six had another developmental disorder. Thus, 50% of infants positive at one screening subsequently received a neurodevelopmental diagnosis. The PREAUT grid scores were significantly associated with medium and high ASD risk status on the CHAT at 24 months (odds ratio of 12.1 (95%CI: 3.0–36.8), p < 0.001, at four months and 38.1 (95%CI: 3.65–220.3), p < 0.001, at nine months). Sensitivity (Se), specificity, negative predictive values, and positive predictive values (PPVs) for PREAUT at four or nine months, and CHAT at 24 months, were similar [PREAUT-4: Se = 16.0 to 20.6%, PPV = 25.4 to 26.3%; PREAUT-9: Se = 30.5 to 41.2%, PPV = 20.2 to 36.4%; and CHAT-24: Se = 33.9 to 41.5%, PPV = 27.3 to 25.9%]. The repeated use of the screening instruments increased the Se but not PPV estimates [PREAUT and CHAT combined: Se = 67.9 to 77.7%, PPV = 19.0 to 28.0%].

Conclusions

The PREAUT grid can contribute to very early detection of ASD and its combination with the CHAT may improve the early diagnosis of ASD and other neurodevelopmental disorders.

Sustainability of an early detection program for autism spectrum disorder over the course of 8 years

The importance of early detection of autism spectrum disorder followed by early intervention is increasingly recognized. This quasi-experimental study evaluated the long-term effects of a program for the early detection of autism spectrum disorder (consisting of training of professionals and use of a referral protocol and screening instrument), to determine whether the positive effects on the age at referral were sustained after the program ended while controlling for overall changes in the number of referrals. Before, during, and after the program, the proportion of children referred before 3 years (versus 3–6 years) of age was calculated for children subsequently diagnosed with autism spectrum disorder (N = 513) or another, non-autism spectrum disorder, condition (N = 722). The odds of being referred before 3 years of age was higher in children with autism spectrum disorder than in children with another condition during the program than before (3.1, 95% confidence interval: 1.2–7.6) or after (1.7, 95% confidence interval: 1.0–3.0) the program but was not different before versus after the program. Thus, although the program led to earlier referral of children with autism spectrum disorder, after correction for other referrals, the effect was not sustained after the program ended. This study highlights the importance of continued investment in the early detection of autism spectrum disorder.

Variation in the Early Trajectories of Autism Symptoms Is Related to the Development of Language, Cognition, and Behavior Problems

OBJECTIVE

The objectives of this study were to model more homogeneous subgroups within autism spectrum disorder (ASD) based on early trajectories of core symptoms; and to further characterize these subgroups in terms of trajectories of language, cognition, co-occurring (attention-deficit/hyperactivity disorder [ADHD]-related) traits and clinical outcome diagnosis.

METHOD

Children (N = 203) referred for possible ASD at ages 1 to 4 years were assessed at three time points at intervals ranging from 9 months to 3 years. Assessments included standardized measures for ASD (Autism Diagnostic Observation Schedule [ADOS]), language (ADOS-language item), nonverbal IQ (NV-IQ; different tests adequate to chronological/mental age), and parent-reported behavioral problems (Infant-Toddler Social and Emotional Assessment, Child Behavior Checklist).

RESULTS

Latent-class growth curve analysis with ADOS total scores led to the identification of three main stable and two small improving groups: a severe-stable group (19.5% of sample)-the only group without considerable language improvement-showed persistent low NV-IQ and marked increase in attention problems over time; a moderate-stable group (21.7%) with below-average increasing NV-IQ; and a mild-stable group (48%) with stable-average NV-IQ and the highest scores on ADHD-related traits, whose ASD outcome diagnoses increased despite stable-low ASD scores. Two groups (each 5.4%) improved: one moved from severe to moderate ASD scores, and the other moved from moderate to mild/nonspectrum scores. Both of these groups improved on language, NV-IQ, and ADHD-related traits.

CONCLUSION

Results support the high stability of ASD symptoms into various severity levels, but also highlight the significant contribution of non-ASD domains in defining and explaining the different ASD trajectories.

Early Identification of Young Children with Autism Spectrum Disorder

Early identification and treatment of children with autism and other developmental disorders is an international priority. Currently there is great interest in lowering the age of identification. Attention has been focused on public awareness campaigns and the regular use of developmental screening tests by health care providers, health workers and others. In this article the authors discuss the rationale for the use of autism specific screening tests, review the characteristics of selected tools, and make recommendations for the diagnostic evaluation of young children for autism spectrum disorder in an international context.

Autism Diagnostic Interview-Revised (ADI-R) Algorithms for Toddlers and Young Preschoolers: Application in a Non-US Sample of 1,104 Children

The current study aimed to investigate the Autism Diagnostic Interview-Revised (ADI-R) algorithms for toddlers and young preschoolers (Kim and Lord, J Autism Dev Disord 42(1):82-93, 2012) in a non-US sample from ten sites in nine countries (n = 1,104). The construct validity indicated a good fit of the algorithms. The diagnostic validity was lower, with satisfactorily high specificities but moderate sensitivities. Young children with clinical ASD and lower language ability were largely in the mild-to-moderate or moderate-to-severe concern ranges of the ADI-R, nearly half of the older and phrase speech ASD-group fell into the little-to-no concern range. Although broadly the findings support the toddler algorithms, further work is required to understand why they might have different properties in different samples to further inform research and clinical use.

Child's verbal ability and gender are associated with age at diagnosis in a sample of young children with ASD in Europe

BACKGROUND

Autism spectrum disorder can in some cases be reliably diagnosed by age 2 years, but in community settings, the mean age at diagnosis is often considerably higher. Later diagnosis has been found to be associated with lower symptom severity, lower parental socioeconomic status and fewer parental concerns. Gender differences in age at diagnosis have been examined, with mixed evidence.

METHODS

We examined the association of child's verbal ability and gender, and parental education, with age at diagnosis in a large sample of young children with autism spectrum disorder in 18 European countries (n = 1410).

RESULTS

There was considerable variation in age at diagnosis across countries. Children with better communication skills were diagnosed significantly later than non-verbal and minimally verbal children. There was also a significant interaction of gender with verbal ability on age at diagnosis, in that female children with complex phrase speech were diagnosed later than male children with the same level of verbal ability.

CONCLUSIONS

Our findings highlight the need to implement public awareness initiatives and training for professionals to promote early detection and, consequently, early intervention for autism spectrum disorder in Europe.

A New Interactive Screening Test for Autism Spectrum Disorders in Toddlers

OBJECTIVE

To develop a clinically valid interactive level 2 screening assessment for autism spectrum disorders (ASD) in toddlers that is brief, easily administered, and scored by clinicians.

STUDY DESIGN

We describe the development, training, standardization, and validation of the Rapid Interactive Screening Test for Autism in Toddlers (RITA-T) with ASD-specific diagnostic instruments. The RITA-T can be administered and scored in 10 minutes. We studied the validity of the RITA-T to distinguish between toddlers with ASD from toddlers with developmental delay (DD)/non-ASD in an early childhood clinic. We also evaluated the test's performance in toddlers with no developmental concerns. We identified a cutoff score based on sensitivity, specificity, and positive predictive value of the RITA-T that best differentiates between ASD and DD/non-ASD.

RESULTS

A total of 61 toddlers were enrolled. RITA-T scores were correlated with ASD-specific diagnostic tools (r = 0.79; P < .01) and ASD clinical diagnoses (r = 0.77; P < .01). Mean scores were significantly different in subjects with ASD, those with DD/non-ASD, and those with no developmental concerns (20.8 vs 13 vs 10.6, respectively; P < .0001). At a cutoff score of >14 , the RITA-T had a sensitivity of 1.00, specificity of 0.84, and positive predictive value of 0.88 for identifying ASD risk in a high-risk group.

CONCLUSION

The RITA-T is a promising new level 2 interactive screening tool for improving the early identification of ASD in toddlers in general pediatric and early intervention settings and allowing access to treatment.

Effectiveness of using the Modified Checklist for Autism in Toddlers in two-stage screening of autism spectrum disorder at the 18-month health check-up in Japan

To determine whether the Modified Checklist for Autism in Toddlers (M-CHAT) in conjunction with the routine 18-month health check-up identifies Japanese toddlers with autism spectrum disorder (ASD). Two-stage screening using the M-CHAT was conducted with 1,851 children attending the check-up. Final ASD diagnosis was confirmed at age ≥3 years. Screening identified 20/51 children with ASD: 12/20 true positives were developmentally delayed, whereas 16/22 false negatives were high-functioning. Sensitivity was 0.476, specificity 0.986, positive predictive value 0.455, and likelihood ratio 33.4 for children with ASD. With a few modifications, M-CHAT screening successfully detected toddlers with ASD with and without developmental delay and is a promising screening tool to complement existing community surveillance.

Screening for autism spectrum disorders: state of the art in Europe

A large number of studies have reported on the validity of autism spectrum disorder (ASD) screening procedures. An overall understanding of these studies' findings cannot be based solely on the level of internal validity of each, since screening instruments might perform differently according to certain factors in different settings. Europe has led the field with the development of the first screening tool and first prospective screening study of autism. This paper seeks to provide an overview of ASD screening studies and ongoing programmes across Europe, and identify variables that have influenced the outcomes of such studies. Results show that, to date, over 70,000 children have been screened in Europe using 18 different screening procedures. Differences among findings across studies have enabled us to identify ten factors that may influence screening results. Although it is impossible to draw firm conclusions as to which screening procedure is most effective, this analysis might facilitate the choice of a screening method that best fits a specific scenario, and this, in turn, may eventually improve early ASD detection procedures.

Children's compliance with American Academy of Pediatrics' well-child care visit guidelines and the early detection of autism

This study estimated compliance with American Academy of Pediatrics (AAP) guidelines for well-child care and the association between compliance and age at diagnosis in a national sample of Medicaid-enrolled children with autism (N = 1,475). Mixed effects linear regression was used to assess the relationship between compliance and age at diagnosis. Mean age at diagnosis was 37.4 (SD 8.4) months, and mean compliance was 55 % (SD 33 %). Children whose care was compliant with AAP guidelines were diagnosed 1.6 months earlier than children who received no well-child care. Findings support that the timely receipt of well-child care may contribute to earlier detection. Additional research on the contribution of compliance, well-child visit components and provider characteristics on the timely diagnosis of autism is needed.

Screening for autism spectrum disorders with the brief infant-toddler social and emotional assessment

OBJECTIVE

Using parent-completed questionnaires in (preventive) child health care can facilitate the early detection of psychosocial problems and psychopathology, including autism spectrum disorders (ASD). A promising questionnaire for this purpose is the Brief Infant-Toddler Social and Emotional Assessment (BITSEA). The screening accuracy with regard to ASD of the BITSEA Problem and Competence scales and a newly calculated Autism score were evaluated.

METHOD

Data, that was collected between April 2010 and April 2011, from a community sample of 2-year-olds (N = 3127), was combined with a sample of preschool children diagnosed with ASD (N = 159). For the total population and for subgroups by child's gender, area under the Receiver Operating Characteristic (ROC) curve was examined, and across a range of BITSEA Problem, Competence and Autism scores, sensitivity, specificity, positive and negative likelihood ratio's, diagnostic odds ratio and Youden's index were reported.

RESULTS

The area under the ROC curve (95% confidence interval, [95%CI]) of the Problem scale was 0.90(0.87-0.92), of the Competence scale 0.93(0.91-0.95), and of the Autism score 0.95(0.93-0.97). For the total population, the screening accuracy of the Autism score was significantly better, compared to the Problem scale. The screening accuracy of the Competence scale was significantly better for girls (AUC = 0.97; 95%CI = 0.95-0.98) than for boys (AUC = 0.91; 95%CI = 0.88-0.94).

CONCLUSION

The results indicate that the BITSEA scales and newly calculated Autism score have good discriminative power to differentiate children with and without ASD. Therefore, the BITSEA may be helpful in the early detection of ASD, which could have beneficial effects on the child's development.

Narrowly versus broadly defined autism spectrum disorders: differences in pre- and perinatal risk factors

This study examined the differential contribution of pre- and perinatal risks in narrowly versus broadly defined autism spectrum disorder (ASD) and across core symptom domains, IQ and co-morbid problems. Children with a DSM-IV diagnosis of autistic disorder (AD) (n = 121) or pervasive developmental disorder not otherwise specified (PDD-NOS) (n = 75) were compared to a typical control sample (n = 311). Diagnoses were based on extensive assessments between 12 and 49 months of age (M = 33.3, SD = 6.4) and re-evaluated at 43-98 months (M = 68.1, SD = 10.7) in 70% of the cases. Compared with controls, cases with ASD were more likely to be firstborn and show a suboptimal condition after birth. Case mothers reported more infections and more stress during pregnancy. Although the ASD subgroups showed mostly overlapping risks, cases with PDD-NOS differed from those with AD by higher exposure to smoking during pregnancy (SDP) and by a negative association of smoking with IQ, regardless of confounders. SDP appears to contribute more to broadly defined (PDD-NOS) than to narrowly defined ASD (AD). Findings suggest differences in etiological contributors between ASD phenotypes.

Measurement Issues: Screening and diagnostic instruments for autism spectrum disorders - lessons from research and practise

BACKGROUND AND SCOPE

Significant progress has been made over the past two decades in the development of screening and diagnostic instruments for autism spectrum disorders (ASDs). This article reviews this progress, including recent innovations, focussing on those instruments for which the strongest research data on validity exists, and then addresses issues arising from their use in clinical settings.

FINDINGS

Research studies have evaluated the ability of screens to prospectively identify cases of ASD in population-based and clinically referred samples, as well as the accuracy of diagnostic instruments to map onto 'gold standard' clinical best estimate diagnosis. However, extension of the findings to clinical services must be done with caution, with a full understanding that instrument properties are sample-specific. Furthermore, we are limited by the lack of a true test for ASD which remains a behaviourally defined disorder. In addition, screening and diagnostic instruments help clinicians least in the cases where they are most in want of direction, as their accuracy will always be lower for marginal cases.

CONCLUSION

Instruments help clinicians to collect detailed, structured information and increase accuracy and reliability of referral for in-depth assessment and recommendations for support, but further research is needed to refine their effective use in clinical settings.

Head circumference and height abnormalities in autism revisited: the role of pre- and perinatal risk factors

Pre/perinatal risk factors and body growth abnormalities have been studied frequently as early risk markers in autism spectrum disorder (ASD), yet their interrelatedness in ASD has received very little research attention. This is surprising, given that pre/perinatal risk factors can have a substantial impact on growth trajectories in the first years of life. We aimed to determine which pre/perinatal factors were more prevalent in ASD children and if these factors differentially influenced body growth in ASD and control children. A total of 96 ASD and 163 control children matched for gender participated. Data of growth of head size and body length during the first 13 months of life were collected. Data on pre/perinatal risk factors were retrospectively collected through standardized questionnaires. Results indicated that after matching for SES, prematurity/low birth weight and being first born were more prevalent in the ASD versus the control group. In addition, with increasing age children with ASD tended to have a proportionally smaller head circumference compared to their height. However, the effect of prematurity/low birth weight on head growth corrected for height was significantly different in ASD and control children: premature/low birth weight control children showed a disproportionate larger head circumference in relation to height during their first year of life, whereas this effect was absent in premature/low birth weight ASD children. This may suggest that the etiology of abnormal growth is potentially different in ASD and control children: where abnormal growth in control children is related to suboptimal conditions in the uterus, abnormal growth in ASD may be more strongly related to the causal factors that also increase the risk for ASD. However, prospective studies measuring growth and ASD characteristics in both premature/low birth weight and a terme children are necessary to support this conclusion.

A new screening programme for autism in a general population of Swedish toddlers

The evidence from early intervention studies of autism has emphasised the need for early diagnosis. Insight into the early presentation of autism is crucial for early recognition, and routine screening can optimise the possibility for early diagnosis. General population screening was conducted for 2.5-year-old children at child health centres in Gothenburg, Sweden, and the efficacy of the screening instruments in predicting a clinical diagnosis of autism was studied. The tools used for autism screening comprised the Modified Checklist for Autism in Children (M-CHAT) and an observation made by trained nurses of the child's joint attention abilities (JA-OBS). From the new screening procedure a "definitive" suspicion of autism spectrum disorder (ASD) was raised in 64 individuals in the study population of 3999 young children. Fifty-four of these were clinically assessed in detail. Forty-eight children had a confirmed diagnosis of ASD, three had severe language disorder, and three (6%) were classified as having typical development. The Positive predictive Value (PPV) for the combination of M-CHAT and the JA-OBS was 90%. The combination of instruments used showed promise for early detection of autism as a routine in the developmental programme at child health centres. Trained medical staff is a basic requirement and enables earlier detection and the use of screening tools beyond routine population screening regardless of the age at which a suspicion of autism is raised.

Early markers of autism spectrum disorders in infants and toddlers prospectively identified in the Social Attention and Communication Study

The Social Attention and Communication Study involved the successful implementation of developmental surveillance of the early markers of autism spectrum disorders in a community-based setting. The objective in the current study was to determine the most discriminating and predictive markers of autism spectrum disorders used in the Social Attention and Communication Study at 12, 18 and 24 months of age, so that these could be used to identify children with autism spectrum disorders with greater accuracy. The percentage of 'yes/no' responses for each behavioural marker was compared between children with autistic disorder (n = 39), autism spectrum disorder (n = 50) and developmental and/or language delay (n = 20) from 12 to 24 months, with a logistic regression also conducted at 24 months. Across all ages, the recurring key markers of both autistic disorder and autism spectrum disorder were deficits in eye contact and pointing, and from 18 months, deficits in showing became an important marker. In combination, these behaviours, along with pretend play, were found to be the best group of predictors for a best estimate diagnostic classification of autistic disorder/autism spectrum disorder at 24 months. It is argued that the identified markers should be monitored repeatedly during the second year of life by community health-care professionals.

Autism spectrum disorder: an emerging opportunity for physical therapy

PURPOSE

A growing body of evidence from research on autism spectrum disorder (ASD) confirms a substantial sensory motor component to ASD. Yet, policy and practice lag behind in recognizing the potential contributions of physical therapists in research, practice, and education related to ASD. The objective of this commentary is to inform and encourage reflection and formal dialogue among pediatric physical therapists regarding the assumption of vital roles in research, education, and clinical practice in ASD.

KEY POINTS

Selected studies representative of the type of work being carried out with respect to motor aspects of ASD is presented with selected older literature for those unfamiliar with the range of information available.

CONCLUSION

Findings from research provide ample substantiation for physical therapists to join interdisciplinary efforts as researchers, scholars, educators, policy analysts, and advocates in ASD. Physical therapists have the potential and ability to play a much greater role in ASD.

Recurrence risk for autism spectrum disorders: a Baby Siblings Research Consortium study

OBJECTIVE

The recurrence risk of autism spectrum disorders (ASD) is estimated to be between 3% and 10%, but previous research was limited by small sample sizes and biases related to ascertainment, reporting, and stoppage factors. This study used prospective methods to obtain an updated estimate of sibling recurrence risk for ASD.

METHODS

A prospective longitudinal study of infants at risk for ASD was conducted by a multisite international network, the Baby Siblings Research Consortium. Infants (n = 664) with an older biological sibling with ASD were followed from early in life to 36 months, when they were classified as having or not having ASD. An ASD classification required surpassing the cutoff of the Autism Diagnostic Observation Schedule and receiving a clinical diagnosis from an expert clinician.

RESULTS

A total of 18.7% of the infants developed ASD. Infant gender and the presence of >1 older affected sibling were significant predictors of ASD outcome, and there was an almost threefold increase in risk for male subjects and an additional twofold increase in risk if there was >1 older affected sibling. The age of the infant at study enrollment, the gender and functioning level of the infant's older sibling, and other demographic factors did not predict ASD outcome.

CONCLUSIONS

The sibling recurrence rate of ASD is higher than suggested by previous estimates. The size of the current sample and prospective nature of data collection minimized many limitations of previous studies of sibling recurrence. Clinical implications, including genetic counseling, are discussed.

Standardized ADOS scores: measuring severity of autism spectrum disorders in a Dutch sample

The validity of the calibrated severity scores on the ADOS as reported by Gotham et al. (J Autism Dev Disord 39: 693–705, 2009), was investigated in an independent sample of 1248 Dutch children with 1455 ADOS administrations (modules 1, 2 and 3). The greater comparability between ADOS administrations at different times, ages and in different modules, as reached by Gotham et al. with the calibrated severity measures, seems to be corroborated by the current study for module 1 and to a lesser extent for module 3. For module 2, the calibrated severity scores need to be further investigated within a sample that resembles Gotham’s sample in age and level of verbal functioning.

A pilot study of abnormal growth in autism spectrum disorders and other childhood psychiatric disorders

The aims of the current study were to examine whether early growth abnormalities are (a) comparable in autism spectrum disorders (ASD) and other childhood psychiatric disorders, and (b) specific to the brain or generalized to the whole body. Head circumference, height, and weight were measured during the first 19 months of life in 129 children with ASD and 59 children with non-ASD psychiatric disorders. Both groups showed comparable abnormal patterns of growth compared to population norms, especially regarding height and head circumference in relation to height. Thus abnormal growth appears to be related to psychiatric disorders in general and is mainly expressed as an accelerated growth of height not matched by an increase in weight or head circumference.

Randomized controlled trial of the focus parent training for toddlers with autism: 1-year outcome

This randomized controlled trial compared results obtained after 12 months of nonintensive parent training plus care-as-usual and care-as-usual alone. The training focused on stimulating joint attention and language skills and was based on the intervention described by Drew et al. (Eur Child Adolesc Psychiatr 11:266–272, 2002). Seventy-five toddlers with autism spectrum disorder (65 autism, 10 PDD-NOS, mean age = 34.4 months, SD = 6.2) were enrolled. Analyses were conducted on a final sample of 67 children (lost to follow-up = 8). No significant intervention effects were found for any of the primary (language), secondary (global clinical improvement), or mediating (child engagement, early precursors of social communication, or parental skills) outcome variables, suggesting that the ‘Focus parent training’ was not of additional value to the more general care-as-usual.

Improved diagnostic validity of the ADOS revised algorithms: a replication study in an independent sample

Recently, Gotham et al. (2007) proposed revised algorithms for the Autism Diagnostic Observation Schedule (ADOS) with improved diagnostic validity. The aim of the current study was to replicate predictive validity, factor structure, and correlations with age and verbal and nonverbal IQ of the ADOS revised algorithms for Modules 1 and 2 in a large independent Dutch sample (N = 532). Results showed that the improvement of diagnostic validity was most apparent for autism, except in very young or low functioning children. Results for other autism spectrum disorders were less consistent. Overall, these findings support the use of the more homogeneous revised algorithms, with the use of similar items across developmental cells making it easier to compare ADOS scores within and between individuals.