Social Responsiveness Scale, Second Edition (SRS-2)

Social Responsiveness Scale, Second Edition (SRS-2)

The SRS-2 identifies social impairment associated with autism spectrum disorders (ASDs) and quantifies its severity.  It’s sensitive enough to detect even subtle symptoms, yet specific enough to differentiate clinical groups, both within the autism spectrum and between ASD and other disorders.  It clearly distinguishes the social impairment characteristic of ASD from that seen in ADHD, anxiety, and other diagnoses.

The SRS-2 is supported by a multitude of independent, peer- reviewed studies involving diverse populations and diagnostic groups.  When the SRS-2 reveals social deficits associated with autism, it identifies where these symptoms fall on the spectrum.  And when the test indicates that autism is not present, it points to other conditions in which social impairment plays a role.

The 5 subscales include;

  • Social Awareness: Ability to pick up on social cues
  • Social Cognition: Ability to interpret social cues once they are picked up
  • Social Communication: Includes expressive social communication
  • Social Motivation: The extent to which a respondent is generally motivated to engage in social-interpersonal behavior; elements of social anxiety, inhibition, and empathic orientation are included here
  • Restricted Interests and Repetitive Behaviors: Includes stereotypical behaviors or highly restricted interests characteristics of autism

Test review of Social Responsiveness Scale, Second Edition (SRS-2)
Yetter, G. (2014).
In J. F. Carlson, K. F. Geisinger, & J. L. Jonson (Eds.), The nineteenth mental measurements yearbook. Retrieved from http://marketplace.unl.edu/buros/

DESCRIPTION
The Social Responsiveness Scale, Second Edition (SRS-2) is a 65-item rating scale assessing symptoms associated with autism in individuals ages 30 months to 89 years. It is intended to be completed by adults familiar with an individual’s social functioning in natural settings.

The SRS-2 consists of four forms: Preschool (ages 30–54 months), School-Age (ages 4–18 years), Adult (ages 19–89 years), and Adult Self-Report. All forms produce two cluster scores: Social Communication and Interaction (SCI; 53 items) and Restricted Interests and Repetitive Behavior (RRB; 12 items), as well as a Total score. The SCI items are divided into four treatment subscales: Social Awareness (8 items), Social Cognition (12 items), Social Communication (22 items), and Social Motivation (11 items). These four subscales were formed based on clinical judgment rather than on statistical analysis, and they are included to assist with intervention development and evaluation in treatment settings.

All items are rated on a 4-point Likert scale anchored by not true and almost always true, where high scores indicate greater dysfunction. Scoring is done by hand and is straightforward. Raw scores are converted into T-scores for interpretation. A summary profile sheet is provided for recording and graphing SCI, RRB, and Total T-scores and for classifying them as within normal limits (T = 59 or lower), mild (T = 60–65), moderate (T = 66–75), or severe (T = 76 or higher). Raters can complete the questionnaire in 15–20 minutes. Scoring and graphing can be completed in 5–10 minutes.

DEVELOPMENT
The SRS-2 is an extension of the SRS (Constantino & Gruber, 2005), a well established screener for autism symptoms for ages 4–18 years. The SRS-2 School-Age form is the same as the original SRS. New Preschool and Adult forms were developed by adapting the wording of items from the School-Age form, generally maintaining item wording to be as similar as possible across the forms.

Diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; American Psychiatric Association, 2013) specified two distinct areas of impairment for Autism Spectrum Disorder (ASD): social communication and interaction impairment and restricted, repetitive patterns of behavior. The appropriateness of the two-dimensional framework for the SRS-2 School-Age form (parent report) was examined with approximately 5,000 school-age children diagnosed with ASDs and 3,000 non-ASD siblings. Results suggested a moderate separation of the SCI and RRB domains. Confirmatory factor analyses with preschool, school-age, and adult samples indicated adequate fit to the two-dimensional model, supporting the interpretation of separate SCI and RRB indices for the various SRS-2 forms.

TECHNICAL
Standardization samples representative of the 2009 U.S. Census according to gender, race, U.S. geographic region, and parents’ educational level were gathered to provide evidence of the technical soundness of the Preschool (n = 247), School-Age (n = 1014), and Adult (n = 702) forms. For each form, the mean ratings were compared by gender, ethnicity, age, and respondent (e.g., parent, teacher, self). The norm samples included too few Asians and Native Americans to support the analysis of ethnic differences with these populations. Using a 3-point T-score difference in mean scores as the criterion for developing separate norm tables, the test authors concluded that whereas for the School-Age form separate norm tables were warranted by respondent and gender, a single norm table was most appropriate for each of the other forms.

The internal consistency of all SRS-2 forms is excellent across gender, age, and respondent for both nonclinical and clinical samples; coefficient alpha values were consistently in the .92–.95 range. Correlation coefficients reflecting interrater agreement for school-age children with ASD were .91 for mothers with fathers and from .72 to .82 for parents with teachers. Interrater reliability of the Preschool form ranged from .70 to .79 for parents with teachers in 6-month age increments. Interrater reliability for the Adult form was fair to good, with correlation coefficients ranging from .66 (comparing self-rating with all other informants) to .88 (comparing mother’s rating with all other informants). Small sample sizes for some age clusters in the adult sample precluded analysis of interrater reliability by respondent and age simultaneously.

Evidence for temporal stability is strong, indicating reliability over time in school age clinical samples where correlation coefficients ranged from .88 to .95 for periods of three months to five years. Test-retest reliability coefficients for school-age general population samples also are acceptable. The test manual does not document the temporal stability of the Adult form or the Preschool form.

Support for the validity of the SRS-2 School-Age form was provided through its convergence with other measures of autism-related symptoms. Correlations with the Social Communication Questionnaire (Rutter, Bailey, & Lord, 2001) yielded coefficients between .58 and .68. Correlation coefficients for the SRS-2 and the Children’s Communication Checklist (Bishop, 1998) ranged from -.49 to -.75. Concordance with the Childhood Autism Rating Scale (Schopler, Reichler, DeVellis, & Daly, 1980) was r = .61. Relationships with the Autism Diagnostic Interview-Revised (ADI-R; Rutter, Le Couteur, & Lord, 2003) were varied, but generally supported the validity of the SRS-2 School-Age form. Correlation coefficients for the SRS-2 and ADI-R domain scores ranged from .26 to .77. Coefficients for the SRS-2 and Autism Diagnostic Observation Schedule domain scores (ADOS; Lord, Rutter, DiLavore, & Risi, 2001) also were variable, ranging from .15 to .58. The relationship of the SRS-2 School-Age form with the Vineland Adaptive Behavior Scales (Sparrow, Balla, & Cicchetti, 1984) was moderate in magnitude (r = -.36 for the Vineland composite and -.34 to -.43 for the subscales) but in the anticipated direction.

The validity of the SRS-2 School-Age form was further evidenced by substantial differences between mean Total SRS-2 scores for children with ASD and those without ASD; M = 106.6 (SD = 30.0) for a group of approximately 5,000 children with ASD versus M = 24.6 (SD = 24.7) for their unaffected siblings. Studies of the Preschool and Adult forms also reported mean scores substantially higher for individuals with ASD or at risk of developmental problems. An area of concern pertains to evidence of higher mean scores for adults ages 60 and over on the Adult form. The mean Total raw score for older adults (n = 127) in the standardization sample was 61, more than 20 points higher than for the overall adult sample.

A receiver operating characteristics (ROC) analysis of the School-Age form revealed test sensitivity of .93 and specificity of .91 when a cutoff score of 60 was used and a sensitivity of .84 and specificity of .94 with a cutoff of 75. ROC analyses have yet to be reported for the Preschool and Adult forms.

COMMENTARY
The original SRS is widely used in both clinical and research settings to measure the severity of ASD symptoms. By extending its age range, the SRS-2 has the potential to expand its applicability. Several concerns with the SRS-2 are noted. First, the item development procedures for the new Preschool and Adult forms were less than optimal. The assumption that items that adequately distinguish ASD symptoms among school-age children will also be appropriate for individuals at other ages (with minimal rewording) is questionable, insofar as the diagnostic utility of items depends on the developmental appropriateness of the behaviors they address. The adequacy of items at both ends of the age range (younger children and older adults) is not sufficiently demonstrated. The representation of older adults in the standardization sample is small, and their mean scores were inexplicably elevated.

Secondly, the test manual offers relatively little evidence supporting the validity of the Preschool and Adult forms. Studies with larger clinical samples are needed, and ROC analyses are needed to establish the test’s sensitivity and specificity at these ages.

SUMMARY
The SRS-2 is a brief, easy to administer Likert rating instrument that may be useful for screening individuals for symptoms of ASDs. The second edition has expanded the age range of the original SRS downward to include preschoolers and upward to include individuals up to age 89. Ample evidence supports its validity and sensitivity for predicting individuals’ ASD-related symptomology for school age children. Further study is needed, however, before the new forms can be used with confidence with adults and preschool children.

REVIEWER’S REFERENCES

  • American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Publishing.
  • Bishop, D. V. M. (1998). Development of the Children’s Communication Checklist (CCC): A method for assessing qualitative aspects of communicative impairment in children. Journal of Child Psychology and Psychiatry, 39, 879–891.
  • Constantino, J. N., & Gruber, C. P. (2005). The Social Responsiveness Scale. Los Angeles, CA: Western Psychological Services.
  • Lord, C., Rutter, M., DiLavore, P. C., & Risi, S. (2001). Autism Diagnostic Observation Schedule (ADOS). Los Angeles, CA: Western Psychological Services.
  • Rutter, M., Bailey, A., & Lord, C. (2001). Social Communication Questionnaire (SCQ). Los Angeles, CA: Western Psychological Services.
  • Rutter, M., Le Couteur, A., & Lord, C. (2003). Autism Diagnostic Interview-Revised (ADI-R). Los Angeles, CA: Western Psychological Services.
  • Schopler, E., Reichler, R., DeVellis, R., & Daly, K. (1980). Toward objective classification of childhood autism: Childhood Autism Rating Scale (CARS). Journal of Autism and Developmental Disorders, 10, 91–103.
  • Sparrow, S. S., Balla, D. A., & Cicchetti, D. V., (1984). Vineland Adaptive Behavior Scales. Circle Pines, MN: American Guidance Service.