[Clinical usefulness of IDEA and CARS: concordance with DSM-IV-TR in children and adolescents with suspicion of PDD]

Assessing autism with DSM-IV and DSM-5 criteria using the Childhood Autism Rating Scale (CARS)

Introduction. The Childhood Autism Rating Scale (CARS) is an observational instrument for assessing autism. It is the most widely used instrument for the diagnosis of autism in Mexico. Objective. To study the psychometric properties in the Mexican population using DSM-IV and DSM-5 criteria. Method. This is an observational, cross-sectional study. Participants (N = 137) were 78.8% male, with an age range between 2 and 18 years, mean 8.5. Parents completed the M-CHAT, the ABC, the ADI-R, and semi-structured clinical interviews with DSM-IV. We inferred DSM-5 criteria by selecting atypical sensory items from the ABC. Results. The internal consistency for the total CARS items was α = .88. The concurrent validity of the CARS and the DSM-IV criteria showed a Spearman coefficient of correlation of rs = .62. The convergent validity with the ADI-R showed moderate correlations, rs = .32 to .61, with the DSM-IV k = .33 and DSM-5 k = .36. The concordance with the DSM-IV and DSM-5 was 71% and 84.5%, sensitivity was 58.1% and 46-7%, and specificity 76.6% and 90.5%, respectively. The discriminant analysis showed that the CARS correctly classified 97% of children with autism, 70% with pervasive developmental disorders not otherwise specified (PDD-NOS), and 12.5% with Asperger’s syndrome. Discussion and conclusion. The Mexican version of the CARS is a valid and reliable instrument for diagnosing autism in Mexican children and adolescents.

Measurement invariance of the Childhood Autism Rating Scale (CARS) across six countries

The Childhood Autism Rating Scale (CARS) is a simple and inexpensive tool for Autism spectrum disorder (ASD) assessments, with evidenced psychometric data from different countries. However, it is still unclear whether ASD symptoms are measured the same way across different societies and world regions with this tool, since data on its cross-cultural validity are lacking. This study evaluated the cross-cultural measurement invariance of the CARS among children with ASD from six countries, for whom data were aggregated from previous studies in India (n = 101), Jamaica (n = 139), Mexico (n = 72), Spain (n = 99), Turkey (n = 150), and the United States of America (n = 186). We analyzed the approximate measurement invariance based on Bayesian structural equation modeling. The model did not fit the data and its measurement invariance did not hold, with all items found non-invariant across the countries. Items related to social communication and interaction (i.e., relating to people, imitation, emotional response, and verbal and nonverbal communication) displayed lower levels of cross-country non-invariance compared to items about stereotyped behaviors/sensory sensitivity (i.e., body and object use, adaptation to change, or taste, smell, and touch response). This study found that the CARS may not provide cross-culturally valid ASD assessments. Thus, cross-cultural comparisons with the CARS should consider first which items operate differently across samples of interest, since its cross-cultural measurement non-invariance could be a source of cross-cultural variability in ASD presentations. Additional studies are needed before drawing valid recommendations in relation to the cultural sensitivity of particular items.

APOE hypermethylation is associated with autism spectrum disorder in a Chinese population

Abnormal apolipoprotein E (APOE) methylation has been demonstrated to be associated with Alzheimer's disease, which may have overlapping mechanisms with autism spectrum disorder (ASD). Thus, the purpose of the present study was to assess the possible link between APOE methylation and ASD. Genomic DNA was extracted from peripheral blood and subjected to a methylation assay. SYBR green-based quantitative methylation-specific polymerase chain reaction analysis was used to measure APOE methylation in 62 pediatric patients with ASD and 73 age-matched healthy subjects. The APOE methylation in each sample was expressed as a percentage of methylation of a reference (PMR). The results indicated that APOE methylation in pediatric patients with ASD was significantly higher than that in the healthy controls (median PMR, 33 vs. 11%; P=2.36×10⁻¹⁰). Receiver operating characteristic curve demonstrated that PMR of 15.4% was the optimal cut-off for predicting ASD (area under curve, 0.817; sensitivity, 93.5%; specificity, 72.6%; P=2.36×10⁻¹⁰). In summary, the present results indicated that APOE hypermethylation in peripheral blood DNA may be used as a diagnostic biomarker for ASD.

Peripheral Inflammatory Markers Contributing to Comorbidities in Autism

This study evaluates the contribution of peripheral biomarkers to comorbidities and clinical findings in autism. Seventeen autistic children and age-matched typically developing (AMTD), between three to nine years old were evaluated. The diagnostic followed the Diagnostic and Statistical Manual of Mental Disorders 4th Edition (DMS-IV) and the Childhood Autism Rating Scale (CARS) was applied to classify the severity. Cytokine profile was evaluated in plasma using a sandwich type ELISA. Paraclinical events included electroencephalography (EEG) record. Statistical analysis was done to explore significant differences in cytokine profile between autism and AMTD groups and respect clinical and paraclinical parameters. Significant differences were found to IL-1β, IL-6, IL-17, IL-12p40, and IL-12p70 cytokines in individuals with autism compared with AMTD (p < 0.05). All autistic patients showed interictalepileptiform activity at EEG, however, only 37.5% suffered epilepsy. There was not a regional focalization of the abnormalities that were detectable with EEG in autistic patients with history of epilepsy. A higher IL-6 level was observed in patients without history of epilepsy with interictalepileptiform activity in the frontal brain region, p < 0.05. In conclusion, peripheral inflammatory markers might be useful as potential biomarkers to predict comorbidities in autism as well as reinforce and aid informed decision-making related to EEG findings in children with Autism spectrum disorders (ASD).

CDC Kerala 11: Diagnosis of autism among children between 2 and 6 y--comparison of CARS against DSM-IV-TR

OBJECTIVES

To compare diagnosis of childhood autism using CARS cut off scores of ≥30 and the new Indian cut off scores of ≥33 against the gold standard DSM-IV-TR criteria available during the study period 2009-10.

METHODS

The study was conducted at the autism clinic of Child Development centre (CDC), Kerala. Two hundred consecutive children between 2 and 6 y with symptoms suggestive of autism were administered both CARS by a trained developmental therapist and DSM-IV-TR by a developmental pediatrician on the same day, both blind to the test results of each other. Diagnosis of autism using CARS cut off scores 30 and above, as suggested in original tool administration manual and 33 and above, as suggested for diagnostic use in Indian population was compared with DSM-IV-TR diagnosis. Data was analyzed using SPSS (version 19.0) software.

RESULTS

Against DSM-IV-TR diagnosis as gold standard, the new CARS cut off scores ≥33 had a higher Specificity (74.3%), Positive predictive value (PPV) (81.9%), Positive likelihood ratio (LR) (2.66) and Negative LR (0.43), but had a lower Sensitivity (68.3%), Negative predictive value (NPV) (57.9%) and accuracy (70.5%), as compared to the cut off scores of ≥30.

CONCLUSIONS

The CARS prevalence of autism for cut off points ≥30 and ≥33 was 71.5 and 52.5% respectively against 63% prevalence by DSM-IV-TR.