The Childhood Asperger Syndrome Test (CAST): test-retest reliability.
The CAST gives steady parent scores across two weeks, so it works for quick ASD screening.
01Research in Context
What this study did
The team asked 37 parents to fill out the Childhood Asperger Syndrome Test twice.
The second form came two weeks later.
They compared the two sets of scores to see if the answers stayed the same.
What they found
Parents gave almost identical answers the second time.
The kappa was 0.70 and the Spearman rho was 0.83.
Those numbers mean the CAST is stable enough for research screening.
How this fits with other research
Mazur et al. (1992) also found stable scores over time, but they waited 2.5 years with adults using the WAIS-R.
The long gap and different tool show the same idea: good tests give steady results.
Green et al. (2020) looked at the Vineland-3 and found it now scores 10-20 points lower than the old Vineland-II.
That update reminds us to check edition changes before we trust old norms.
Dupuis et al. (2021) showed the ABAS-II lines up well with the Vineland-II in kids with ASD.
Together these papers say parent forms can be trusted, but always know which version you have.
Why it matters
You can feel safe using the CAST as a quick screen in your intake packet.
If a child scores high, the score will likely stay high two weeks later.
Still, keep the Vineland edition and ABAS-II findings in mind when you pick follow-up tools.
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02At a glance
03Original abstract
The Childhood Asperger Syndrome Test (CAST) is a 37-item parental self-completion questionnaire to screen for autism spectrum conditions in research. Good test accuracy was demonstrated in studies with primary school aged children in mainstream schools. The aim of this study was to investigate the test-retest reliability of the CAST. Parents of 1000 children in years 1-6 in five mainstream primary schools in Cambridgeshire received the CAST. A second identical questionnaire was posted to respondents after approximately 2 weeks. Both mailings generated 136 responses. Agreement above and below a screening cut-point of 15 was investigated. The kappa statistic for agreement (< 15 versus > or = 15) was 0.70, and 97 percent (95 percent CI: 93-99 percent) of children did not move across the cut-point of 15. The correlation between the two test scores was 0.83 (Spearman's rho). The CAST has shown good test-retest reliability, and now requires further investigation in a high-scoring sample.
Autism : the international journal of research and practice, 2006 · doi:10.1177/1362361306066612