TY - JOUR PY - 2015// TI - Computerized adaptive testing of population psychological distress: simulation-based evaluation of GHQ-30 JO - Social psychiatry and psychiatric epidemiology A1 - Stochl, Jan A1 - Böhnke, Jan R. A1 - Pickett, Kate E. A1 - Croudace, Tim J. SP - 895 EP - 906 VL - 51 IS - 6 N2 - 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.

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.

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.

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.

Language: en

LA - en SN - 0933-7954 UR - http://dx.doi.org/10.1007/s00127-015-1157-4 ID - ref1 ER -