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Childhood Autism Rating Scale - 2nd Edition

The purpose of the Childhood Autism Rating Scale – Second Edition (CARS-2; Schopler, Van Bourgondien, Wellman, & Love,2010) is to identify the presence of autism in children and to determine the severity of symptoms. Items related to fifteen functional domains can be completed by anyone who knows the child well.

Available from WPS


The purpose of the Childhood Autism Rating Scale – Second Edition (CARS™-2; Schopler, Van Bourgondien, Wellman, & Love, 2010) is to help identify the presence of autism in children and to determine the severity of symptoms. It is an individually administered, behavioral rating scale that is completed by someone who knows the child well. Fifteen functional domains are rated on a 4-point scale. Based on informant or clinician observation, the clinician assigns ratings in each domain related to frequency, peculiarity, intensity, and duration. The CARS-2 has two versions: the Standard form, CARS-2-ST, for individuals less than 6 years of age and those with communication difficulties or below-average estimated IQs; and the CARS-2-HF for those 6 years and over who are verbally fluent and have IQ scores over 80. The CARS-2-HF is designed to identify the more subtle characteristics of those with “high-functioning” forms of ASD. The CARS2 also includes a third form, the Questionnaire for Parents or Caregivers (CARS-2-QPC), an unscored scale useful for collecting information for use in making CARS-2-ST and CARS-2-HF ratings.


Age: 2 years - 62 years

Time to Administer: 5-10 min. to rate items (after gathering the information needed)

Method of Administration: 15-item rating scales completed by clinician on a 7-point scale based on observation, parent report, and other records

Yields cutoff scores, standard scores, and percentile ranks

CARS-2 QPC. Unscored form: completed by parent or caregiver. These responses become the framework for follow-up interview information.

Notes on ages:
-CARS-2-ST: 2 years to < 6 and those with communication difficulties or below average estimated IQs
-CARS-2-HF: 6+ years for verbally fluent individuals with IQ scores over 80
-CARS-2-QPC: For parent or caregiver of an individual of any age.

Subscales: OVERALL SCORE: Total Score

Relating to People; Imitation (ST)/Social- Emotional Understanding (HF); Body Use; Object Use (ST)/Object Use in Play (HF); Adaptation to Change (ST)/Adaptation to Change/Restricted Interests (HF); Visual Response; Listening Response; Taste, Smell, & Touch Response and Use; Fear or Nervousness (ST)/Fear or Anxiety (HF); Verbal Communication; Activity Level (ST)/ Thinking/Cognitive Integration Skills (HF); Level and Consistency of Intellectual Response; General Impressions

QPC: Early Development; Social; Emotional and Communication; Repetitive Behaviors; Play and Routines; Unusual Sensory Interests

Screening/Diagnosis: D

Autism Related Research

Research regarding the CARS-2 is included on the table below. Research findings specific to the original CARS (Schopler, Reichler, & Renner, 1988) may also be helpful for clinician information. Such findings include the following: (a) significant correlations were found between total score of the CARS and domain scores of the Autism Diagnostic Interview-Revised (ADI-R), supporting concurrent validity of the two; however the CARS classified more cases with autism than did the ADI-R, leading the authors to conclude that the CARS represents a broader diagnostic concept of autism and suggesting the CARS may be most useful for screening (Saemundsen, Magnusson, Smari, & Sigurdardottir, 2003); (b) factor structure assessed shortly after the development of the original instrument did not hold across studies, though each identified ASD related constructs conceptually consistent with DSM-IV; however, Magyar and Pandolfi (2007) concluded that the CARS’ psychometric properties, conceptual relevance, and flexible administration procedures support its continued use as a screening instrument; (c) Perry and colleagues (2005) conducted a study that demonstrated high concordance between the CARS and clinical ASD diagnoses, though they emphasized the need to use the CARS in conjunction with other data gathering approaches; and (d) similarly, in another study the CARS was found to have 100% agreement with DSM-IV diagnoses in a sample of 54 children, though the CARS did not clearly differentiate types of developmental disorders (Rellini, Tortolani, Trillo, Carbone, & Montecchi, 2004).

Dawkins, Meyer, & Van Bourgondien (2016)

Age Range: 1-62 years

Sample Size: 183

Topics Addressed:

Utility of CARS-2-ST and CARS-2-HF to identify ASD under both the DSM-IV-TR and DSM-5 criteria

Outcome:Dawkins, Meyer, & Van Bourgondien (2016)

High sensitivity (range 81-100%) and specificity (range 70-100%) for both versions of the CARS-2 when using DSM-IV-TR and DSM-5 criteria. CARS-2-ST was very high in specificity, while CARS-2-HF was very high in sensitivity.

Conclusion: overall, the diagnostic agreement of the CARS-2 is high across both DSM-IV-TR and DSM-5 criteria for autism and can be used as a diagnostic tool within a broader evaluation encompassing multiple sources of information