A Validation Study of the Korean Version of Social Communication Questionnaire

Diagnosis and Assessment of Autism Spectrum Disorder in South Korea

Autism spectrum disorder (ASD) is diagnosed by the clinical decision of a trained professional based on the Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition or International Classification of Diseases 11th Revision diagnostic criteria. To obtain information for diagnostic formulation, professionals should explore detailed developmental history, and can use structured or semi-structured assessment tools to observe interaction between the child and parents or strangers. Diagnostic assessment should include a profile of the strength and weaknesses of the individual and should be conducted using an optimal approach by a multidisciplinary team with appropriate techniques and experience. Assessment of language, cognitive, neuropsychological, and adaptive functioning should be conducted in ASD individuals prior to establishing an individualized treatment plan. Genetic testing, brain magnetic resonance imaging or electroencephalogram testing can be considered for identification of underlying causes.

Validation of the social communication questionnaire amongst Nigerian adolescents

Few autism spectrum disorder (ASD) screening tools have been developed and validated in Africa. This study aimed to examine the psychometric properties of the Social Communication Questionnaire (SCQ) when used with Nigerian adolescents. Parents and caregivers of two hundred and five adolescents completed the SCQ Lifetime form while the adolescents were assessed for ASD using the Autism Diagnostic Observation Schedule, 2nd Edition (ADOS-2). Factor structure and convergent and discriminative validity were examined, along with the sensitivity and specificity of the SCQ in identifying participants with an autism spectrum disorder. The confirmatory factor analysis (CFA) was used to examine the factor structure, while logistic regression and Pearson's correlation coefficient were used to examine the validities. The SCQ had good internal consistency, discriminative, and convergent validity. A cut-off score of 10 revealed sensitivity = 0.81 and specificity = 0.88 for the identification of autism spectrum disorder. AUC was 0.83, p < 0.001, 95% CI [0.77, 0.90]. The results of this study provide evidence to support the retention of the original four factors of the SCQ. The SCQ has good psychometric properties when used with Nigerian adolescents.

Descriptive Analysis of Social Interaction and Communication Skills of Autistic Children According to Sibling Status and Characteristics

OBJECTIVE

Sibling relationships in early childhood can have a positive impact on children's social interaction and communication skills. Similarly, autistic children can benefit from interactions with their siblings, who can serve as readily available partners for social interaction. However, there is a lack of research on the effects of siblings based on specific characteristics of the sibling. Therefore, the aim of this study is to compare social interactions and communication skills of autistic children based on sibling status and characteristics.

METHODS

We conducted a retrospective data review involving 895 autistic children and their siblings at Seoul National University Bundang Hospital. Variety of diagnostic assessments or questionnaires were administered. Based on the characteristics of the data, Quade's test for nonparametric analysis of covariance was used to compare autism-related symptoms and levels of functioning of the autistic child according to 1) sibling status, 2) birth order, 3) sex, and 4) diagnosis of the sibling. Pearson correlation was used to explore associations between the sibling age gap and different clinical scores.

RESULTS

Having siblings was associated with fewer difficulties in restricted and repetitive behaviors. Based on the comparison of the Autism Diagnostic Interview-Revised scores, autistic children with multiple siblings demonstrated better nonverbal behaviors. Autistic children with autistic siblings experienced greater difficulties in social interactions and communications, such as peer relationships, sharing enjoyment, and engaging in social imitative play.

CONCLUSION

The study revealed differences in social interactions and communication skills of autistic children based on sibling status, birth order, affected sibling, age gap, and sex.

Metaverse-based social skills training programme for children with autism spectrum disorder to improve social interaction ability: an open-label, single-centre, randomised controlled pilot trial

Background

Autism spectrum disorder (ASD) is characterised by abnormalities in social interactions and restricted and repetitive behaviors. Children with high-functioning ASD (HFASD), lack social communication skills, do not interact with others, and lack peer relationships. We aimed to develop, and evaluate the feasibility of, a metaverse-based programme to enhance the social skills of children with HFASD.

Methods

This open-label, single-centre, pilot parallel randomised controlled trial (RCT) was conducted on boys aged 7-12 years with HFASD. Children were recruited from a treatment centre for children with HFASD in Korea or by self-referral through online community webpages for the parents of children with HFASD. Participants were randomly assigned (1:1) by a blinded researcher to receive either four weeks of a metaverse-based social skills training programme or a control group. Randomisation was stratified by age (children aged 7-9 and 10-12 years) using permuted blocks (block size 4). The metaverse-based social skills training programme was delivered via the metaverse platforms (Roblox) and Zoom. Children in the intervention group completed the metaverse-based social skills training programme at home for four weeks. The intervention consisted of four sessions, one session per week, for 60 min each. The control group did not receive any interventions. The primary outcome measure was the median change in the Social Responsiveness Scale-2 (SRS-2) scores from pre-to post-intervention. SRS-2 is an assessment tool used to confirm the effectiveness of social interactions. Higher scores indicate lower social functioning. The trial is registered with CRIS Registration Number; KCT0006859.

Findings

Between February 14, 2022, and March 31, 2022, 20 participants were enrolled. Overall, 15 children (median [Interquartile range (IQR)] age, intervention group: 9.0 [8.0-10.0]; control group: 8.5 [8.0-10.0]) participated in the programme. The intervention group included nine participants (60%), and the control group included six participants (40%). The SRS-2 total scores for the intervention group decreased from baseline 96.0 (IQR: 74.0-112.0) to post-intervention 85.0 (IQR: 84.0-103.0). The group median difference in SRS-2 scores between the intervention and control groups was 11.5 (95% CI: 8.5-14.0), with a further reduction in the intervention group. Similar trends were seen for social cognition (group median difference, 95% CI: 2.0, 1.0-4.0), social communication (group median difference, 95% CI: 2.0, 1.0-4.0), and autistic mannerism (group median difference, 95% CI: 4.0, 1.0-5.0). There were no adverse events related to study participation.

Interpretation

The findings of this feasibility study suggest that children with HFASD can potentially be familiarised, through metaverse-based programmes, with real-life social situations to improve sociality and reduce emotional and behavioural problems. Such interventions could be delivered at home and possibly be extended to target groups that have difficulty in interacting with peers offline.

Funding

The Institute of Information & Communications Technology Planning & Evaluation grant, via the Ministry of Science and ICT of the South Korean Government.

Loss of Acquired Skills: Regression in Young Children With Autism Spectrum Disorders

Objectives

Regression, while not a core symptom of autism spectrum disorder (ASD), has been suggested to be a distinct subtype by previous studies. Therefore, this study aimed to explore the prevalence and clinical differences between those with and without regression in children with ASD.

Methods

This study includes data from toddlers and young children aged 2-7 years acquired from other projects at Seoul National University Bundang Hospital. The presence and characteristics of regression were explored using question items #11-28 from the Autism Diagnostic Interview-Revised. Chi-square and independent t-tests were used to compare various clinical measurements such as autistic symptoms, adaptative behavior, intelligence, and perinatal factors.

Results

Data from 1438 young children (1020 with ASD) were analyzed. The overall prevalence rate of regression, which was mainly related to language-related skills, was 10.2% in the ASD group, with an onset age of 24 months. Regarding clinical characteristics, patients with ASD and regression experienced ASD symptoms, especially restricted and repetitive interests and behaviors, with greater severity than those without regression. Furthermore, there were significant associations between regression and hypertension/placenta previa.

Conclusion

In-depth surveillance and proactive interventions targeted at young children with ASD and regression should focus on autistic symptoms and other areas of functioning.

Diagnostic validity of Autism Diagnostic Observation Schedule, second edition (K-ADOS-2) in the Korean population

Background

Although the Korean version of the Autism Diagnostic Observation Schedule-2 (K-ADOS‐2) is widely being used to diagnose autism spectrum disorder (ASD) in South Korea, no previous study has examined the validity and reliability of all modules of K-ADOS-2 across a wide age range, particularly older children, adolescents, and adults.

Method

Data from 2,158 participants were included (mean age = 79.7 months; 73.6% male): 1473 participants with ASD and 685 participants without ASD (Toddler Module, n = 289; Module 1, n = 642; Module 2 n = 574; Module 3 n = 411; Module 4, n = 242). Participants completed a battery of tests, including the K-ADOS or K-ADOS-2 and other existing diagnostic instruments. Sensitivity, specificity, area under the receiver operating characteristic (ROC) curve, positive predictive value (PPV), negative predictive value (NPV), Cohen’s kappa (k), and agreement with existing diagnostic instruments were computed. Cronbach’s α values were also calculated.

Results

All developmental cells of the K-ADOS-2 showed sufficient ranges of sensitivity 85.4–100.0%; specificity, 80.4–96.8%; area under the ROC curve, .90-.97; PPV, 77.8–99.3%; NPV, 80.6–100.0%; and k values, .83–.92. The kappa agreements of developmental cells with existing diagnostic instruments ranged from .20 to .90. Cronbach’s α values ranged from .82 to .91 across all developmental cells.

Limitation

The best-estimate clinical diagnoses made in this study were not independent of the K-ADOS-2 scores. Some modules did not include balanced numbers of participants in terms of gender and diagnostic status.

Conclusion

The K-ADOS-2 is a valid and reliable instrument in diagnosing ASD in South Korea. Future studies exploring the effectiveness of the K-ADOS-2 in capturing restricted, repetitive behaviors and differentiating ASD from other developmental disabilities are needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13229-022-00506-5.

The validity and reliability of the simplified Chinese version of the Social Communication Questionnaire

This study aims to validate the simplified Chinese version of the Social Communication Questionnaire (SCQ) in children aged 2-12 years from both general and clinical populations. We recruited 819 Chinese children in this study, including 505 typically developing (TD) children, 202 children with autism spectrum disorder (ASD) and 112 children with non-ASD neurodevelopmental disorders. All the children's parents completed the simplified Chinese version of the SCQ and all children with ASD were additionally assessed for intelligence and the Childhood Autism Rating Scale to confirm their diagnosis. We have developed a 40-item, 4-factor structure of SCQ with two domains (social communication and social interaction; and restricted, repetitive, and stereotyped patterns of behavior), which showed adequate goodness of fit (comparative fit index [CFI] = 0.96, Tucker-Lewis index [TLI] = 0.95, standardized root mean squared residual [SRMR] = 0.07, root mean square error of approximation [RMSEA] = 0.05), with good internal consistency (Cronbach's alpha = 0.92). We have provided different cut-offs to distinguish ASD cases from TD children (11 for children under 4 years [sensitivity: 0.96, specificity: 0.95], 12 for children 4 years and above [sensitivity: 0.93, specificity: 0.98]) or children with other neurodevelopmental disorders (14 [sensitivity: 0.85, specificity: 0.88]). Through this large sample validation, we confirmed that the simplified Chinese version of the SCQ could be used for children aged 2-12 years with relatively good psychometric properties. LAY SUMMARY: We aimed to develop the simplified Chinese version of the Social Communication Questionnaire (SCQ) for Chinese children aged 2-12 years as a screening tool to identified potential risk of autism spectrum disorder (ASD). We have developed a 40-item, 4-factor structure of SCQ with two domains, which showed adequate goodness of fit and good psychometric properties. We also provided different cut-offs to identify ASD cases in general or clinical populations.

Patterns of Restricted and Repetitive Behaviors in Toddlers and Young Children with Autism Spectrum Disorder

Objectives

Restricted and repetitive behaviors (RRBs) are a core symptom in the diagnosis of autism spectrum disorder (ASD). The complexity of behavioral patterns has called for the creation of phenotypically homogeneous subgroups among individuals with ASD. The purpose of this study was 1) to investigate the different types of RRBs and 2) to explore whether subgroups created by RRBs would show unique levels of functioning in toddlers and young children with ASD.

Methods

A total of 313 children with ASD, aged 12–42 months were included in the analysis. The Autism Diagnostic Interview-Revised was used to obtain information on the different types of RRBs by grouping 15 items into six categories. The Vineland Adaptive Behaviors Scale, a parent-reported questionnaire, was used to measure adaptive functioning. A portion of the children were analyzed separately for verbal-related RRBs based on their expressive language level. Two-step cluster analysis using RRB groups as features was used to create subgroups. Analysis of covariance while covarying for age and language was performed to explore the clinical characteristics of each cluster group.

Results

Sensory-related RRBs were the most prevalent, followed by circumscribed interests, interest in objects, resistance to change, and repetitive body movements. A subset of the children was analyzed separately to explore verbal-related RRBs. Four cluster groups were created based on reported RRBs, with multiple RRBs demonstrating significant delays in adaptive functioning.

Conclusion

Heterogeneity of RRBs emerges at a young age. The different patterns of RRBs can be used as valuable information to determine developmental trajectories with better implications for treatment approaches.

The Role of Ion Channel-Related Genes in Autism Spectrum Disorder: A Study Using Next-Generation Sequencing

The clinical heterogeneity of autism spectrum disorder (ASD) is closely associated with the diversity of genes related to ASD pathogenesis. With their low effect size, it has been hard to define the role of common variants of genes in ASD phenotype. In this study, we reviewed genetic results and clinical scores widely used for ASD diagnosis to investigate the role of genes in ASD phenotype considering their functions in molecular pathways. Genetic data from next-generation sequencing (NGS) were collected from 94 participants with ASD. We analyzed enrichment of cellular processes and gene ontology using the Database for Annotation, Visualization, and Integrated Discovery (DAVID). We compared clinical characteristics according to genetic functional characteristics. We found 266 genes containing nonsense, frame shift, missense, and splice site mutations. Results from DAVID revealed significant enrichment for “ion channel” with an enrichment score of 8.84. Moreover, ASD participants carrying mutations in ion channel-related genes showed higher total IQ (p = 0.013) and lower repetitive, restricted behavior (RRB)-related scores (p = 0.003) and mannerism subscale of social responsiveness scale scores, compared to other participants. Individuals with variants in ion channel genes showed lower RRB scores, suggesting that ion channel genes might be relatively less associated with RRB pathogenesis. These results contribute to understanding of the role of common variants in ASD and could be important in the development of precision medicine of ASD.

Validation of Social Responsiveness Scale for Korean Preschool Children With Autism

OBJECTIVE

This cross-cultural study aims to examine the psychometric properties of the Social Responsiveness Scale (SRS) and to determine the best-estimate-cut-off scores for the diagnosis of autism spectrum disorder (ASD) in Korean preschool children.

METHODS

A total of 563 children was recruited from multiple sources, including Seoul National University Bundang Hospital. Participants were assessed by a multidisciplinary research team using multiple diagnostic tools based on DSM-5 diagnostic criteria. Discriminative validity was tested by comparing the difference in SRS scores between ASD and non-ASD groups. Convergent validity was tested by examining correlations between SRS scores with other diagnostic instruments. A receiver operation characteristic curve analysis was conducted to test the sensitivity and specificity of SRS and to determine the best-estimate-cut-off scores for screening ASD in Korean preschool children.

RESULTS

There were significant differences in the total SRS scores between the ASD (n=242) and non-ASD group (n=321) (p<0.01, 95% confidence interval [CI]: 14.08-17.24). The differences were significant even after adjusting for age. SRS scores were significantly correlated with other prescreening diagnostic tools for ASD. The best-estimate cut-off score to screen ASD was 55 (area under curve=0.88, sensitivity 78.1%, specificity 86.6%).

CONCLUSION

The SRS is a valid and reliable instrument to screen and aid in the diagnosis of ASD in Korean preschool children. The adjusted cut-off scores, notably lower than in the original U.S. version, may yield a more accurate diagnosis by reflecting transcultural differences.

Changes in Children with Autism Spectrum Disorder after Theraplay Application

Objectives

This study identified changes in social communication and interaction among children with autism spectrum disorder (ASD) through Theraplay.

Methods

This study included 20 children who were diagnosed with ASD by a child and adolescent psychiatrist and were recommended to undergo Theraplay in 2012–2017. The Marschak interaction method was used to identify and analyze the interactions between parents and their children. The Korean version of the Social Communication Questionnaire (K-SCQ) was used to evaluate symptoms of ASD. The Wilcoxon signed-rank test was used to compare the differences before and after Theraplay.

Results

Upon comparing the differences in total K-SCQ scores, there were statistically significant changes (z=-3.269, p=0.001) in children with ASD. Changes were also confirmed in each category, namely social interaction, communication, and limited and repetitive behavior patterns (p=0.011, p=0.025, p=0.039, respectively).

Conclusion

This study found that Theraplay may cause significant changes in social communication in children with ASD. Further studies are needed to establish the effectiveness of Theraplay in children with ASD.

Short caregiver interview and play observation for early screening of autism spectrum disorder: Behavior development screening for toddlers (BeDevel)

This study validates behavior development screening for toddlers (BeDevel), which utilizes a combination of short caregiver interviews (BeDevel-I) and semistructured play observations (BeDevel-P). The data of 431 toddlers (male 66.2%; mean age (SD) = 29.11 (8.59) months; ASD, n = 201; developmental delay, n = 46; typically developing, n = 184), aged 18 ~ 42 months, were included in the validation of BeDevel. The best clinical estimate diagnosis, screening rate, validity, sensitivity, and reliability of BeDevel were determined based on data cross-sectionally collected using BeDevel and existing diagnostic/screening instruments: autism diagnostic observation schedule (ADOS), autism diagnostic interview (ADI-R), Vineland adaptive behavior scales-II (VABS-II), social response scales (SRS), sequenced language scale for infants (SELSI), Korean childhood autism rating scale (K-CARS), and Korean social communication questionnaire (K-SCQ). The k values of BeDevel-I and BeDevel-P were 0.055 ~ 0.732 and 0.291 ~ 0.752, respectively. Items related to social referencing in BeDevel-P had a particularly high diagnostic validity (k = 0.483 ~ 0.684). Reliabilities of BeDevel-I and BeDevel-P were sufficient (Cronbach's alpha = 0.86 ~ 0.88 and 0.92 ~ 0.95, respectively). BeDevel-I and BeDevel-P showed high sensitivity (BeDevel-I: 85.00 ~ 89.29%; BeDevel-P: 85.00 ~ 91.75%), specificity (BeDevel-I: 77.55 ~ 89.55%; BeDevel-P: 85.09 ~ 97.01%), PPV (BeDevel-I: 70.83 ~ 88.54%; BeDevel-P: 81.52 ~ 94.68%), and NPV (BeDevel-I: 76.00 ~ 95.24%; BeDevel-P: 84.62 ~ 95.45%). The agreement between the composite BeDevel score and ADOS, ADI-R, K-CARS, and K-SCQ was >67.6% (range = 67.6 ~ 90.8%). Combining a short caregiver interview and direct play observation is a valid and reliable screening process. More studies on social referencing as an important early marker are needed. BeDevel can be utilized as a secondary screening instrument before diagnostic confirmation in clinical and community settings. LAY SUMMARY: BeDevel, which consists of a short caregiver interview and direct play observation, is a valid and reliable screening instrument for autism spectrum disorder (ASD). We suggest that BeDevel can be utilized as a secondary instrument before administering diagnostic assessments in clinical and community settings. More studies examining social referencing as a potential behavioral marker of ASD are needed.

Validating the Autism Diagnostic Interview-Revised in the Korean Population

OBJECTIVE

This study aimed to examine the validity of the Korean version of the Autism Diagnostic Interview-Revised (K-ADI-R) and determine its efficacy in identifying individuals with autism spectrum disorder (ASD).

METHODS

Data were pooled from several past and ongoing studies as well as clinical records acquired at Seoul National University Bundang Hospital from 2008 to 2017. The K-ADI-R were administered and scored by trained research reliable examiners. Measurements to investigate the validity of the K-ADI-R was through sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), and Cohen's kappa.

RESULTS

A total of 1,271 (age 88.9±62.42 months, male=927) participants were included. The K-ADI-R yielded strong psychometric properties with high sensitivity (86.06-99.27%), specificity (84.75-99.55%), PPV (92.33-99.72%), and NPV (79.43-98.64%). There were significant differences in item scores across the K-ADI-R diagnostic algorithm regardless of age and sex (p<0.001). Agreement between the K-ADI-R and other ASD related measurements ranged between levels of good to excellent.

CONCLUSION

Despite language or cultural boundaries, the K-ADI-R demonstrated high levels of sensitivity, specificity, PPV, and NPV within a wide range of participants; hence, suggesting promising usage as a valuable diagnostic instrument for individuals with ASD.

Next-Generation Sequencing in Korean Children With Autism Spectrum Disorder and Comorbid Epilepsy

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social communication and restricted and repetitive behaviors and interests. Identifying the genetic background may be one of the key features for the future diagnosis and treatment of ASD. With the tremendous development in genetic diagnosis techniques, next-generation sequencing (NGS) can be used to analyze multiple genes simultaneously with a single test in laboratory and clinical settings and is well suited for investigating autism genetics. According to previous studies, there are two types of genetic variants in ASD, rare variants and common variants, and both are important in explaining pathogenesis. In this study, NGS data from 137 participants with ASD were reviewed retrospectively with consideration for comorbid epilepsy. Diagnostic yield was 17.51% (24/137), and pathogenic/likely pathogenic variants were seen more frequently in female participants. Fourteen participants were diagnosed with comorbid epilepsy, six of them had pathogenic/likely pathogenic variants (43%). Genes with variants of unknown significance (VOUS) which have one or more evidence of pathogenicity following the American College of Medical Genetics (ACMG) criteria were also reviewed in both ASD and ASD with comorbid epilepsy groups. We found that most frequently found VOUS genes have previously been reported as genes related to ASD or other developmental disorders. These results suggest that when interpreting the NGS results in the clinical setting, careful observation of VOUS with some pathological evidence might contribute to the discovery of genetic pathogenesis of neurodevelopmental disorders such as ASD and epilepsy.

Age as a Moderator of Social Skills Intervention Response Among Korean Adolescents with Autism Spectrum Disorder

Few studies have investigated the effect of age on treatment effectiveness of evidence-based social skills training in autism spectrum disorder (ASD) adolescents. This study evaluated the effectiveness of Program for the Education and Enrichment of Relational Skills (PEERS^®) in different ages of ASD adolescents. A total of 110 ASD adolescents aged 11-19 years were divided into early, middle, and late adolescence groups, and the changes in outcome measures following intervention were compared among the three groups. We found that the improvements in social competence after PEERS^® were significant, but the treatment effects were not significantly different among the three age groups. The findings suggest that PEERS^® is beneficial for ASD adolescents regardless of patient age and adolescence stage.

Reliability and Validity of the Korean Translation of Quantitative Checklist for Autism in Toddlers: A Preliminary Study

Objectives:

We aimed to assess the test-retest reliability, internal consistency, and validity of the Korean version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT).

Methods:

The Korean version of the Q-CHAT and the Korean version of the Child Behavior Checklist (CBCL) 1.5-5 were completed by parents of 24 toddlers and preschoolers with autism spectrum disorder (ASD) and 80 unselected toddlers and preschoolers. Parents of the ASD group also completed the Social Communication Questionnaire (SCQ), and Childhood Autism Rating Scale (CARS) scores were obtained from medical records.

Results:

The ASD group scored higher on the Q-CHAT than the unselected group. The Cronbach’s alpha coefficient of the Q-CHAT was 0.658, and test-retest reliability was calculated to be 0.836. The estimated area under the curve was 0.793. The total scores of the Q-CHAT in the ASD group demonstrated significant positive correlations with findings regarding pervasive development problems in the CBCL, SCQ, and CARS. A total score of 33.5 may be a useful cutoff point to use when identifying toddlers at risk of ASD.

Conclusion:

The Korean version of the Q-CHAT has good reliability and validity and can be used as a screening tool in order to identify toddlers and preschool children at risk of ASD.

Prenatal and postnatal bisphenol A exposure and social impairment in 4-year-old children

BACKGROUND

Prenatal and postnatal exposure to bisphenol A (BPA) may affect early brain development. Rodent studies suggest that prenatal and postnatal neurodevelopmental toxicity from BPA exposure may manifest as social deficits in offspring. We investigated the association between prenatal and postnatal exposure to BPA and social impairments in a sample of 4-year-old children.

METHODS

We recruited second-trimester pregnant women between 2008 and 2011, and measured their creatinine-adjusted prenatal urine BPA levels. In 2014-2015, a subset of 4-year-old children born to these women underwent neurobehavioral assessment and physical examination. We collected urine and blood from the children and assessed social impairments, including deficits in social interaction, social communication, and other behavior patterns using the Korean version of the Social Communication Questionnaire (K-SCQ) (n = 304). We examined social impairments associated with prenatal exposure at mid-term pregnancy and postnatal exposure to BPA at 4 years of age, using linear and piecewise linear regression models.

RESULTS

The relationship between prenatal BPA exposure and social communication was non-linear and statistically significant at or above the flexion point for BPA levels of 3.0 μg/g creatinine in girls (58.4%, 95% confidence interval [CI], 6.5% to 135.8%). Each 2-fold increase in postnatal BPA exposure was significantly associated with an 11.8% (95% CI, 0.6% to 24.3%) increase in impairment in social communication in 4-year old girls, as indicated by the linear regression model.

CONCLUSION

Prenatal and postnatal BPA exposure is associated with social impairment at 4 years of age, particularly in girls.