Constructs assessed by the GARS-2: factor analysis of data from the standardization sample.
The GARS-2 (Gilliam 2006) is widely used for autism screening; however, the validity of its three conceptually-derived subscales has not been evaluated. In this study, exploratory (EFA) and confirmatory (CFA) factor analyses of data from matched subgroups of the standardization sample did not support the GARS-2 subscale structure. EFAs identified four factors in the model development subgroup (n = 496): stereotyped/repetitive behavior, stereotyped/idiosyncratic language, word use problems, and social impairment. CFAs supported this model in the replication subgroup (n = 494). Findings suggest that the GARS-2 subscales have limited clinical utility and that the Autism Index should be interpreted with caution. Although more research is needed, the clinical utility of the four empirically-derived scales may be limited by factors related to item content and test development procedures.
School Psychology Department, Rochester Institute of Technology, Rochester, NY 14623, USA. vxpgla@rit.edu
Vincent
V
Pandolfi
Caroline I
CI
Magyar
Charles A
CA
Dill
D000293:Adolescent; D001321:Autistic Disorder / Q000175:diagnosis* / Q000523:psychology; D002648:Child; D002675:Child, Preschool; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D011581:Psychological Tests / Q000592:standards*; D011594:Psychometrics; D015203:Reproducibility of Results; D012919:Social Behavior; D013239:Stereotyped Behavior; D055815:Young Adult