TY - JOUR
T1 - Replication and validation of higher order models demonstrated that a summary score for the EORTC QLQ-C30 is robust
AU - Giesinger, Johannes M.
AU - Kieffer, Jacobien M.
AU - Fayers, Peter M.
AU - Groenvold, Mogens
AU - Petersen, Morten Aa.
AU - Scott, Neil W.
AU - Sprangers, Mirjam A. G.
AU - Velikova, Galina
AU - Aaronson, Neil K.
AU - EORTC Quality of Life Group
N1 - Copyright © 2015 Elsevier Inc. All rights reserved.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - 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.
AB - 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.
U2 - 10.1016/j.jclinepi.2015.08.007
DO - 10.1016/j.jclinepi.2015.08.007
M3 - Journal article
C2 - 26327487
SN - 0895-4356
VL - 69
SP - 79
EP - 88
JO - Journal of Clinical Epidemiology
JF - Journal of Clinical Epidemiology
ER -
