Ethnic Group Differences in the Timing of Autism Diagnosis, Intellectual Disability, and Educational Placement of Autistic Children in Singapore.

AIM: Given Singapore's distinct multicultural identity, this study examined the hypotheses that there may be ethnic group differences in diagnosis and outcomes in autistic children in Singapore. METHODS: Retrospective data were obtained from medical records of all children born between 2008 and 2011 who were diagnosed with clinical or confirmed autism. One-way ANOVAs and regression analyses were used to analyze data. RESULTS: Data from 2577 medical records were extracted. There were more boys (82.5%) and ethnic group distribution was Chinese (67%), Malay (14%), Indian (10%), and Others (10%). Chinese children were more likely to present at a developmental clinic with concerns 3-4 months younger compared to Malay children and those from Other Races (F(3, 2038) = 9.58, p < .001, Cohen's F = 0.12). Chinese children were also more likely to receive an autism diagnosis approximately 3 months younger compared to Malay children. Fewer autistic Chinese children were diagnosed with co-occurring intellectual disability (13.1%) while there were almost twice more Malay children than expected with co-occurring intellectual disability (29.9%) (χ2 (3) = 55.17, p < .001). There are correspondingly more Malay children on the autism spectrum who attend special education schools. Possible confounding variables such as household income level and mother's level of education were identified in some of these findings. CONCLUSION: Several significant ethnic group differences in autistic children in Singapore exist that warrant more investigation into possible causes and support systems needed, with implications for other ethnically diverse nations.

A Direct Comparison of Three Screening Methods for Autism Spectrum Disorder in a High-Likelihood Sibling Population.

Targeted screening of children at increased likelihood of autism is recommended. However, autism screening tools are usually validated for use mainly in low-likelihood populations. This study compared the accuracy of the Modified Checklist for Autism in Toddlers, Revised with Follow-up (M-CHAT-R/F), the ASDetect app, and the Social Attention and Communication Surveillance, Revised (SACS-R). Siblings of autistic children underwent autism screening at 12, 18 and 30 months old. At each visit, caregivers completed the M-CHAT-R/F and ASDetect while trained nurses tested the siblings using the SACS-R. At 36 to 48 months, the siblings underwent an Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) assessment. 189 siblings were screened, 141 completed the study, and 32 were confirmed to have autism. Although not validated for use at 12 months, the M-CHAT-R/F had the best sensitivity among the three tools for this age group, suggesting that early signs are already apparent to caregivers. The M-CHAT-R/F had overall better sensitivity (0.72-0.83) across all age groups, but with overall lower specificity (0.55-0.77). The SACS-R and ASDetect had better positive predictive values at 18 and 30 months (0.60-0.68), while the M-CHAT-R/F was 0.43-0.48. Negative predictive values were generally high across all three tools across all age groups (0.78-0.93). Targeted screening of children at high likelihood of autism yielded a detection rate of 22.7% and should therefore be implemented routinely to facilitate early detection and intervention. The performance of autism screening tools should be examined in higher-likelihood populations for targeted screening of these children.

Brief Report: Investigating the Implications of Applying the New DSM-5 Criteria for Diagnosing Autism Spectrum Disorder in a Preschool Population in Singapore.

Diagnostic reports for 206 children who underwent an assessment for autism spectrum disorder (ASD) using the DSM-IV-TR criteria, were re-evaluated using the DSM-5 criteria. Mean age of the children at time of diagnosis was 3 years 10 months. Of the 202 children diagnosed with ASD on the DSM-IV-TR, 184 (91.1 %) also met the DSM-5 criteria for ASD. The overall concordance rate of ASD diagnosis on the DSM-IV-TR and DSM-5 was higher than that reported in other studies. Of the 18 children who did not meet DSM-5 criteria for ASD, 16 children met all social communication criteria but did not fulfil at least two restricted and repetitive behaviour (RRB) criteria. Six of those children had further RRBs emerging later on follow-up.

The Utility of Developmental Checklists in Parent-held Health Records in Singapore.

OBJECTIVE: The aim of this study was to investigate parents' perceptions of developmental checklists and the child development monitoring schedule in the Singapore health booklet. METHOD: Parents of children aged 2 years 6 months to 3 years 11 months with or without developmental concerns (n = 450) completed a structured interview, and their child's health booklets were reviewed. RESULTS: Most parents reported reading and using the developmental checklists. However, only about half of them attempted the checklists with minimal help from professionals. Approximately 7 in 10 parents of children with developmental concerns found the checklists useful for identifying concerns about their child. Despite positive feedback from parents about the checklists, only about 1 in 4 parents brought their child for a 2 to 3 years developmental monitoring visit at the time of the survey, and the completion rates of the checklists were less than desirable. CONCLUSIONS: Further revisions to the checklists can include simplifying the words and sentences and providing relevant pictures to aid understanding. If the checklists are to be used for screening, standardization of how the checklists are to be completed and how children at risk of developmental delays can be identified on the checklists need to be provided. Parents' awareness of the importance of evaluating their child's development at 9 months, 18 months, and particularly at 2.5 years, needs to be raised. Developmental screening for children at these critical ages can be made mandatory. An electronic version of the health booklet is likely to facilitate implementation of developmental screening in the health care system.

The clinical utility of the modified checklist for autism in toddlers with high risk 18-48 month old children in Singapore.

The modified checklist for autism in toddlers (M-CHAT) is a tool developed for 16-30 month old children to screen for autism spectrum disorders (ASD). It is a well-researched tool, but little is known about its utility with Singaporean toddlers and with older children referred for developmental concerns. This study investigated the M-CHAT's performance with 18-30 month old (N = 173) and >30-48 month old (N = 407) developmentally at-risk Singaporean children, when used with three recommended scoring methods i.e., the total, critical and Best7 scoring methods. The results indicate that the critical and Best7 scoring methods detected most true cases of ASD without inflating the false positive rates in toddlers, and that only the total scoring method performed acceptably for the older children.

Evidence for a cultural influence on field-independence in autism spectrum disorder.

Field-independence, or weak central coherence, is a recognised phenotype of autism spectrum disorder (ASD). There is also evidence of cultural variation in this perceptual style, as neurotypical individuals from Western nations are more field-independent than neurotypical individuals from East-Asian nations. The majority of research on perceptual style in those with ASD has been carried out in Western nations therefore it is unclear whether increased field-independence in ASD is a culturally universal phenotype. Here, we assessed perceptual style in children with and without ASD from England and Singapore using the Children's Embedded Figures Test and the Framed-Line Test. We found increased field-independence in the English participants with ASD only, suggesting that weak central coherence in ASD is not culturally universal.

Contrast sensitivity for motion detection and direction discrimination in adolescents with autism spectrum disorders and their siblings.

The magnocellular (M) pathway hypothesis proposes that impaired visual motion perception observed in individuals with Autism Spectrum Disorders (ASD) might be mediated by atypical functioning of the subcortical M pathway, as this pathway provides the bulk of visual input to cortical motion detectors. To test this hypothesis, we measured luminance and chromatic contrast sensitivity, thought to tap M and Parvocellular (P) pathway processing, respectively. We also tested the hypothesis that motion processing is impaired in ASD using a novel paradigm that measures motion processing while controlling for detectabilty. Specifically, this paradigm compares contrast sensitivity for detection of a moving grating with contrast sensitivity for direction-of-motion discrimination of that same moving grating. Contrast sensitivities from adolescents with ASD were compared to typically-developing adolescents, and also unaffected siblings of individuals with ASD (SIBS). The results revealed significant group differences on P, but not M, pathway processing, with SIBS showing higher chromatic contrast sensitivity than both participants with ASD and TD participants. This atypicality, unique to SIBS, suggests the possible existence of a protective factor in these individuals against developing ASD. The results also revealed impairments in motion perception in both participants with ASD and SIBS, which may be an endophenotype of ASD. This impairment may be driven by impairments in motion detectors and/or by reduced input from neural areas that project to motion detectors, the latter possibility being consistent with the notion of reduced connectivity between neural areas in ASD.

Spatial contrast sensitivity in adolescents with autism spectrum disorders.

Adolescents with autism spectrum disorders (ASD) and typically developing (TD) controls underwent a rigorous psychophysical assessment that measured contrast sensitivity to seven spatial frequencies (0.5-20 cycles/degree). A contrast sensitivity function (CSF) was then fitted for each participant, from which four measures were obtained: visual acuity, peak spatial frequency, peak contrast sensitivity, and contrast sensitivity at a low spatial frequency. There were no group differences on any of the four CSF measures, indicating no differential spatial frequency processing in ASD. Although it has been suggested that detail-oriented visual perception in individuals with ASD may be a result of differential sensitivities to low versus high spatial frequencies, the current study finds no evidence to support this hypothesis.