Use of item response theory to develop a shortened version of the EORTC QLQ-C30 emotional functioning scale

J. Bjorner (Corresponding Author), M. A. Petersen, M. Groenvold, N. Aaoronson, M. Ahlner-Elmqvist, J. I. Arraras, A. Bredart, Peter Fayers, M. S. Jordhøy, M. Sprangers, M. Watson, T. Young, European Organisation for Research and Treatment of Cancer

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Abstract

Background: As part of a larger study whose objective is to develop an abbreviated version of the EORTC QLQ-C30 suitable for research in palliative care, analyses were conducted to determine the feasibility of generating a shorter version of the 4-item emotional functioning (EF) scale that could be scored in the original metric. Methods: We used data from 24 European cancer studies conducted in 10 different languages (n = 8242). Item selection was based on analyses by item response theory (IRT). Based on the IRT results, a simple scoring algorithm was developed to predict the original 4-item EF sum scale score from a reduced number of items. Results: Both a 3-item and a 2-item version ( item 21 'Did you feel tense?' and item 24 'Did you feel depressed?') predicted the total score with excellent agreement and very little bias. In group comparisons, the 2-item scale led to the same conclusions as those based on the original 4-item scale with little or no loss of measurement efficiency. Conclusion: Although these results are promising, confirmatory studies are needed based on independent samples. If such additional studies yield comparable results, incorporation of the 2-item EF scale in an abbreviated version of the QLQ-C30 for use in palliative care research settings would be justified. The analyses reported here demonstrate the usefulness of the IRT-based methodology for shortening questionnaire scales.

Original languageEnglish
Pages (from-to)1683-1697
Number of pages15
JournalQuality of Life Research
Volume13
Issue number10
DOIs
Publication statusPublished - Dec 2004

Keywords

  • cancer
  • IRT
  • palliative care
  • prediction
  • quality of life
  • shortening of scales
  • OF-LIFE QUESTIONNAIRE
  • PALLIATIVE CARE
  • OUTCOME MEASURES
  • CANCER-PATIENTS
  • PARTIAL CREDIT
  • VALIDATION
  • LINKING
  • MODELS

Cite this

Bjorner, J., Petersen, M. A., Groenvold, M., Aaoronson, N., Ahlner-Elmqvist, M., Arraras, J. I., Bredart, A., Fayers, P., Jordhøy, M. S., Sprangers, M., Watson, M., Young, T., & European Organisation for Research and Treatment of Cancer (2004). Use of item response theory to develop a shortened version of the EORTC QLQ-C30 emotional functioning scale. Quality of Life Research, 13(10), 1683-1697. https://doi.org/10.1007/s11136-004-7866-x