Replication and validation of higher order models demonstrated that a summary score for the EORTC QLQ-C30 is robust

Johannes M Giesinger; Jacobien M Kieffer; Peter M Fayers; Mogens Groenvold; Morten Aa Petersen; Neil W Scott; Mirjam A G Sprangers; Galina Velikova; Neil K Aaronson; EORTC Quality of Life Group

doi:10.1016/j.jclinepi.2015.08.007

Replication and validation of higher order models demonstrated that a summary score for the EORTC QLQ-C30 is robust

J Clin Epidemiol. 2016 Jan:69:79-88. doi: 10.1016/j.jclinepi.2015.08.007. Epub 2015 Sep 28.

Authors

Johannes M Giesinger¹, Jacobien M Kieffer¹, Peter M Fayers², Mogens Groenvold³, Morten Aa Petersen⁴, Neil W Scott⁵, Mirjam A G Sprangers⁶, Galina Velikova⁷, Neil K Aaronson⁸; EORTC Quality of Life Group

Collaborators

EORTC Quality of Life Group:
M King, S Leutenegger, N Spry, E Greimel, B Holzner, A Bottomley, C Coens, K West, G de Castro, C de Souza, A Bezjak, M Whitehead, M Groenvold, M Klee, M Petersen, A Bredart, T Conroy, C Rodary, M Berend, B Bestmann, M Koller, O Krauß, T Kuchler, B Malchow, R Schwarz, K Mystakidou, A Montazeri, C Brunelli, M Tamburini, T Matsuoka, H Zhao, N Aaronson, A de Graeff, C Gundy, R de Leeuw, M Muller, M Sprangers, K Bjordal, E Brenne, M Hjermstad, M Jordhøy, P Klepstad, S Sundstrøm, F Wisløff, Y B Cheung, S B Tan, J Thumboo, H B Wong, Y H Yun, J Arraras, H Jayasekara, L Rajapakse, M Ahlner-Elmqvist, P Ballabeni, J Bernhard, W-C Chie, U Abacioglu, J Blazeby, J Bruce, A Davies, P Fayers, L Friend, Z Krukowski, T Massett, J Nicklin, J Ramage, N Scott, A Smyth-Cull, T Young, D Cella, D-L Esseltine, C Gotay, I Pagano

Affiliations

¹ Division of Psychosocial Research and Epidemiology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
² Institute of Applied Health Sciences, University of Aberdeen, Foresterhill Road, AB25 2ZD Aberdeen, UK; Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Postboke 8905, N-7491 Trondheim, Norway.
³ The Research Unit, Department of Palliative Medicine, Bispebjerg Hospital, Bispebjerg Bakke 23, 2400 Copenhagen, Denmark; Department of Public Health, University of Copenhagen, Øster Farimagsgade 5, 1014 Copenhagen, Denmark.
⁴ The Research Unit, Department of Palliative Medicine, Bispebjerg Hospital, Bispebjerg Bakke 23, 2400 Copenhagen, Denmark.
⁵ Institute of Applied Health Sciences, University of Aberdeen, Foresterhill Road, AB25 2ZD Aberdeen, UK.
⁶ Department of Medical Psychology, Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
⁷ Leeds Institute of Cancer and Pathology, St James's Institute of Oncology, University of Leeds, Beckett Street, LS9 7TF Leeds, UK.
⁸ Division of Psychosocial Research and Epidemiology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands. Electronic address: n.aaronson@nki.nl.

PMID: 26327487
DOI: 10.1016/j.jclinepi.2015.08.007

Abstract

Objective: To further evaluate the higher order measurement structure of the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30), with the aim of generating a summary score.

Study design and setting: Using pretreatment QLQ-C30 data (N = 3,282), we conducted confirmatory factor analyses to test seven previously evaluated higher order models. We compared the summary score(s) derived from the best performing higher order model with the original QLQ-C30 scale scores, using tumor stage, performance status, and change over time (N = 244) as grouping variables.

Results: Although all models showed acceptable fit, we continued in the interest of parsimony with known-groups validity and responsiveness analyses using a summary score derived from the single higher order factor model. The validity and responsiveness of this QLQ-C30 summary score was equal to, and in many cases superior to the original, underlying QLQ-C30 scale scores.

Conclusion: Our results provide empirical support for a measurement model for the QLQ-C30 yielding a single summary score. The availability of this summary score can avoid problems with potential type I errors that arise because of multiple testing when making comparisons based on the 15 outcomes generated by this questionnaire and may reduce sample size requirements for health-related quality of life studies using the QLQ-C30 questionnaire when an overall summary score is a relevant primary outcome.

Keywords: Confirmatory factor analysis; EORTC QLQ-C30; Health-related quality of life; Higher order factor scores; Measurement model; Questionnaires.

Publication types

Research Support, Non-U.S. Gov't
Validation Study

MeSH terms

Female
Humans
Male
Middle Aged
Models, Statistical*
Neoplasms* / therapy
Quality of Life*
Surveys and Questionnaires*

Grants and funding

MR/L01629X/1/MRC_/Medical Research Council/United Kingdom