Reliability and validity of the Dutch version of the Glasgow Anxiety Scale for people with an Intellectual Disability (GAS-ID).
The Dutch GAS-ID is a sensitive anxiety screener for adults with ID—refer everyone who scores ≥17 for full psychiatric work-up.
01Research in Context
What this study did
The team translated the Glasgow Anxiety Scale for people with an Intellectual Disability into Dutch.
They then checked if the new Dutch form gives steady answers across time and raters.
Adults with intellectual disability living in the Netherlands served as participants.
What they found
The Dutch GAS-ID is good at catching true anxiety.
It gives similar scores when the same person retakes it.
The downside: it sometimes flags people who actually have other mental-health problems, not anxiety.
How this fits with other research
English et al. (1995) did the same kind of work with the Dutch Reiss Screen. Both studies show the tool works, yet warn that sub-scores can wobble.
Hoekstra-van Duijn et al. (2025) later tested the Dutch MEDS. Their numbers were even stronger, hinting that newer Dutch ID tools are getting sharper.
Oliver et al. (2002) and Gustafsson et al. (2005) saw the same pattern in Swedish forms: total scores are trustworthy, single-item ratings less so.
Why it matters
You now have a quick Dutch checklist that sensitively spots anxiety in adults with ID. Use it as a first screen. If someone scores 17 or higher, refer on even if they do not look anxious. The false-positive risk is real, but missing true anxiety costs more.
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02At a glance
03Original abstract
BACKGROUND: In the Netherlands, no self-report screening questionnaire for anxiety in people with intellectual disabilities (ID) was available yet. Therefore, we have translated the Glasgow Anxiety Scale for people with an Intellectual Disability (GAS-ID) into Dutch and studied its reliability and validity in adults with borderline, mild or moderate ID. METHOD: Test-retest reliability was studied in 66 participants, convergent validity against the Anxiety sub-scale of the Hospital, Anxiety and Depression Scale (HADS-A) in 96, and criterion validity against psychiatric diagnosis in 195 participants. RESULTS: Internal consistency was α = 0.86 and test-retest reliability ICC = 0.89 (95% CI: 0.82-0.93). Correlation with the HADS-A was r = 0.61 (95% CI: 0.47-0.72); sensitivity was 83.9% (95% CI: 72.2-91.2) and specificity was 51.8% (95% CI: 43.6-59.9) using a cut-off score of 17. Missed diagnoses (false-negatives) were mostly specific phobias. Of the false-positives, 38 of 66 participants (58%) had another psychiatric diagnosis. CONCLUSIONS: The Dutch version of the GAS-ID is a reliable screening instrument with satisfactory sensitivity, but moderate specificity for anxiety disorders. Although specificity for anxiety disorders is only moderate, high scores appear to be indicative of other psychiatric problems too, justifying referral for psychiatric assessment of false-positives.
Journal of intellectual disability research : JIDR, 2013 · doi:10.1111/j.1365-2788.2012.01632.x