Gilliam Autism Rating Scale Second Edition

Eric Rozenblat, M.A., BCBA

Caldwell College

Assessment Project

2

Overview

Background of GARS II Changes from original GARS to GARS II Peer-reviewed literature about GARS Description/Administration of GARS II Scoring of GARS II Pros and Cons about GARS II Recommended Usages

3

Background of GARS

Originally published in 1995 (Gilliam, 1995)– Based on definition of autism in DSM IV and Autism

Society of America (1994) – Reliable and valid standardized test

Goal of GARS – Tests for reliability– Tests for validity

Used in schools and clinics internationally

Background of GARS

56-items divided into 4 subscales– Stereotyped Behaviors– Communcation– Social Interaction– Developmental Disturbances

Autism Quotient Scores and probability of having autism – Below 69 = very low– 70-79 = low– 80-89 = below average– 90-110 = average– 111-120 = above average– 120-130 = high– 131+ = very high

4

5

Revisions from original GARS

1. Development Disturbances subscale converted into interview

2. Re-written items

3. Demographic characteristics

4. New norms created

5. Autism Index

6. Guidelines for scores

7. Discrete target behaviors

8. Instructional Objectives for Children Who Have Autism

South et al. (2002)

The purpose of the South et al. study investigated the validity of using the GARS (1st edition) for children with pre-exisisting diagnoses of autism.

Examined GARS data for 119 children Results showed mean GARS IQ was 90.10 Developmental Disturbances subscale not

coorelated Limitation

6

7

Lecavalier (2005)

Purpose was to examine construct and diagnostic validity, interrater reliability, and effects of participant characteristics on GARS scores

8

Lecavalier (2005)

29 school districts across Ohio– Children selected between 3-21 who receive educational

services for ASD’s

Data collected from parents and teacher Final analysis included two components

– Possess minimal language skills, expressive language at or above 20-month level

– Minimum raw score

Lecavilier (2005)

Verify information– Parents asked if their child had been diagnosed by

physician or psychologist as having an ASD and…– Teachers reported students classification as noted

in their IEP

Final sample:– 284 students, 225 male, 47 female, 12 no gender– 195 autism, 35 pre-k disability, 29 misc, 25 none

9

10

Lecavilier (2005) Results

Three factor analysis for construct validity – Factor 1-Stereotyped Behavior

One item did not belong, 7 others did from 2 subscales

– Factor 2-CommunicationAll but 3 within communication belonged

– Factor 3-Social InteractionNo items coorelated

No statistical differences on three behavioral subscales No statistical difference between teacher/parent ratings

Other References

Eaves 2006-reliability and validity of GARS– Results supported use of GARS as screening tool

11

12

DSM-IV-TR

Important to consider Diagnostic Criteria of Autism in DSM-IV-TR– A total of six or more items from 1, 2, and 3 with at

least 2 from 1 and one each from 2 and 31. Qualitative impairment in social interaction

2. Qualitiative impairment in communication

3. Restricted and repetitive stereotyped patterns of behavior

13

Description/Administration of GARS II

42 clearly stated items divided into three subscales

Parent Interview Most current definitions Normed scale on 1,107 representatives Objective 5-10 min to administer

14

Description/Administration of GARS II

Three subscales with 14 items each– Stereotyped Behaviors

Example includes rocks back and forth

– Communication Example includes repeats words or phrases over and over

– Social Interaction Example includes avoids eye contact

Examiner/Rater Qualifications

Scoring Presentation

Tables A-1 and A-2

15

Normative Data

See table 4.1

16

Reliability and Validity

See back of test

17

GARS II and ABA

See Chapter 7 in Examiner Book and Instructional Objectives for Children Who Have Autism

18

PROS and CONS

Pros ConsEasy to administer GARS II not enough to DX

Takes little time Anecdotal parent questionnaire

Good reliability Lack of peer-reviewed research on GARSII

Good validity Raters may be subjective

Easy to compute Examiner may not administer test on own

Relation to ABA Does not describe environmental contingencies

Direct Observation Examiner qualifications (need specialists in autism with license)

Easy to score

Uses DSM IV Definition

Large Normative Sample19

Recommended Usages

Eaves et al. (2006)– The analysis of the internal consistency of the

GARS supported its use as a screening device

California Collaborative Work Group on Autism Spectrum Disorders (1997)

The Quality Standards Subcommittee of the American Academy of Neurology

The Child Neurology Center (Filipek et al. 2000)

20

Recommended Usages

Recommended not as primary measure

Autism specialists

Interpret with skepticism

21

Questions

22

References

American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed., text rev.).

Washington, DC: Author.

Boggs, K.M., Gross, A.M., & Gohm, C.L. (2006). Validity of the Asperger Syndrome Diagnostic Scale. Journal of

Developmental and Physical Disabilities, 18, 163-182.

Bruininks, R.H., Woodcock, R.W., Weatherman, R.F., & Hill, B.K. (1996). Scales of independent behavior-Revised:

Manual. Boston: Riverside Publishing Company.

California Departments of Education and Developmental Services Collaborative Work Group on Autism Spectrum

Disorders. (1997). Best practices for designing and delivering effective programs for individuals with autistic

spectrum disorders. Available online at www.feat.org.

Eaves, R.C., Woods-Groves, S., Williams Jr., T.O., & Fall, A.M. (2006). Reliability and validity of the pervasive

developmental disorders rating scale and the gilliam autism rating scale. Education and Training in

Developmental Disabilities, 41, 300-309.23

References

Filipek, P.A., Accardo, P.J., Baranek, G.T., Cook, E.H., Dawson, G. et al. (1999). The screening and diagnosis of autism

spectrum disorders. Journal of Autism and Developmental Disorders, 29, 439-484.

Gilliam, J.E. (2006). Gilliam Autism Rating Scale. (2nd ed.). Austin, TX: PRO-ED.

Gilliam, J.E. (1995). Gilliam Autism Rating Scale. Austin, TX: PRO-ED.

Lecavalier, L. (2005). An evaluation of the gilliam autism rating scale. Journal of Autism and Developmental Disorders, 35,

795-805.

Lopez, B.R., Lincoln, A.J., Ozonoff, S., & Lai, Z. (2005). Examining the relationship between executive functions and

restricted, repetitive symptoms of autistic disorder. Journal of Autism and Developmental Disorders, 35, 445-460.

South, M., Williams, B.J., McMahon, W.M., Owley, T., Filipek, P.A., Shernoff, E., Corsello, C., Lainhart, J.E., Landa, R., &

Ozonoff, S. (2002). Utility of the gilliam autism rating scale in research and clinical populations. Journal of Autism and

Developmental Disorders, 32, 593-599.

Walz, N.C. (2007). Parent reports of stereotyped behaviors, social interaction, and developmental disturbances in individuals

with angelman syndrome. Journal of Autism and Developmental Disorders, 37, 940-947. 24