@article{ref1,
title="Computerized adaptive testing of population psychological distress: simulation-based evaluation of GHQ-30",
journal="Social psychiatry and psychiatric epidemiology",
year="2015",
author="Stochl, Jan and Böhnke, Jan R. and Pickett, Kate E. and Croudace, Tim J.",
volume="51",
number="6",
pages="895-906",
abstract="PURPOSE: Goldberg's General Health Questionnaire (GHQ) items are frequently used to assess psychological distress but no study to date has investigated the GHQ-30's potential for adaptive administration. In computerized adaptive testing (CAT) items are matched optimally to the targeted distress level of respondents instead of relying on fixed-length versions of instruments. We therefore calibrate GHQ-30 items and report a simulation study exploring the potential of this instrument for adaptive administration in a longitudinal setting. <br><br>METHODS: GHQ-30 responses of 3445 participants with 2 completed assessments (baseline, 7-year follow-up) in the UK Health and Lifestyle Survey were calibrated using item response theory. Our simulation study evaluated the efficiency of CAT administration of the items, cross-sectionally and longitudinally, with different estimators, item selection methods, and measurement precision criteria. <br><br>RESULTS: To yield accurate distress measurements (marginal reliability at least 0.90) nearly all GHQ-30 items need to be administered to most survey respondents in general population samples. When lower accuracy is permissible (marginal reliability of 0.80), adaptive administration saves approximately 2/3 of the items. For longitudinal applications, change scores based on the complete set of GHQ-30 items correlate highly with change scores from adaptive administrations. <br><br>CONCLUSIONS: The rationale for CAT-GHQ-30 is only supported when the required marginal reliability is lower than 0.9, which is most likely to be the case in cross-sectional and longitudinal studies assessing mean changes in populations. Precise measurement of psychological distress at the individual level can be achieved, but requires the deployment of all 30 items.<p /> <p>Language: en</p>",
language="en",
issn="0933-7954",
doi="10.1007/s00127-015-1157-4",
url="http://dx.doi.org/10.1007/s00127-015-1157-4"
}