Evidence-based guidelines for determination of sample size and interpretation of the European Organisation for the Research and Treatment of Cancer quality of life questionnaire core 30 (EORTC QLQ-C30)

Kim Cocks (Corresponding Author), Madeleine T. King, Galina Velikova, Marrissa Martyn St-James, Peter Fayers, Julia M. Brown

Research output: Contribution to journalArticle

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Abstract

Purpose
To use published literature to estimate large, medium, and small differences in quality of life (QOL) data from the European Organisation for the Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30).
Methods
An innovative method combining systematic review of published studies, expert opinions, and meta-analysis was used to estimate large, medium, and small differences for QLQ-C30 scores. Published mean data were identified from the literature. Differences (contrasts) between groups (eg, between treatment groups, age groups, and performance status groups) were reviewed by 34 experts in QOL measurement and cancer treatment. The experts, blinded to actual QOL results, were asked to predict these differences. A large difference was defined as one representing unequivocal clinical relevance. A medium difference was defined as likely to be clinically relevant but to a lesser extent. A small difference was one believed to be subtle but nevertheless clinically relevant. A trivial difference was used to describe circumstances unlikely to have any clinical relevance. Actual QOL results were combined using meta-analytic techniques to estimate differences corresponding to small, medium, or large effects.
Results
Nine hundred eleven articles were identified, leading to 152 relevant articles (2,217 contrasts) being reviewed by at least two experts. Resulting estimates from the meta-analysis varied depending on the subscale. Thus, the recommended minimum to detect medium differences ranges from 9 (cognitive functioning) to 19 points (role functioning).
Conclusion
Guidelines for the size of effects are provided for the QLQ-C30 subscales. These guidelines can be used for sample size calculations for clinical trials and can also be used to aid interpretation of differences in QLQ-C30 scores
Original languageEnglish
Pages (from-to)89-96
Number of pages8
JournalJournal of Clinical Oncology
Volume29
Issue number1
Early online date22 Nov 2010
DOIs
Publication statusPublished - 1 Jan 2011

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Sample Size
Quality of Life
Organizations
Guidelines
Research
Neoplasms
Meta-Analysis
Therapeutics
Expert Testimony
Age Groups
Surveys and Questionnaires
Clinical Trials

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Evidence-based guidelines for determination of sample size and interpretation of the European Organisation for the Research and Treatment of Cancer quality of life questionnaire core 30 (EORTC QLQ-C30). / Cocks, Kim (Corresponding Author); King, Madeleine T.; Velikova, Galina; Martyn St-James, Marrissa; Fayers, Peter; Brown, Julia M.

In: Journal of Clinical Oncology, Vol. 29, No. 1, 01.01.2011, p. 89-96.

Research output: Contribution to journalArticle

@article{93c00eb2c1014397915533828a6138b0,
title = "Evidence-based guidelines for determination of sample size and interpretation of the European Organisation for the Research and Treatment of Cancer quality of life questionnaire core 30 (EORTC QLQ-C30)",
abstract = "PurposeTo use published literature to estimate large, medium, and small differences in quality of life (QOL) data from the European Organisation for the Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30).MethodsAn innovative method combining systematic review of published studies, expert opinions, and meta-analysis was used to estimate large, medium, and small differences for QLQ-C30 scores. Published mean data were identified from the literature. Differences (contrasts) between groups (eg, between treatment groups, age groups, and performance status groups) were reviewed by 34 experts in QOL measurement and cancer treatment. The experts, blinded to actual QOL results, were asked to predict these differences. A large difference was defined as one representing unequivocal clinical relevance. A medium difference was defined as likely to be clinically relevant but to a lesser extent. A small difference was one believed to be subtle but nevertheless clinically relevant. A trivial difference was used to describe circumstances unlikely to have any clinical relevance. Actual QOL results were combined using meta-analytic techniques to estimate differences corresponding to small, medium, or large effects.ResultsNine hundred eleven articles were identified, leading to 152 relevant articles (2,217 contrasts) being reviewed by at least two experts. Resulting estimates from the meta-analysis varied depending on the subscale. Thus, the recommended minimum to detect medium differences ranges from 9 (cognitive functioning) to 19 points (role functioning).ConclusionGuidelines for the size of effects are provided for the QLQ-C30 subscales. These guidelines can be used for sample size calculations for clinical trials and can also be used to aid interpretation of differences in QLQ-C30 scores",
author = "Kim Cocks and King, {Madeleine T.} and Galina Velikova and {Martyn St-James}, Marrissa and Peter Fayers and Brown, {Julia M.}",
note = "Acknowledgment We thank Cancer Research United Kingdom for funding for the Evidence-Based Interpretation Guidelines (EBIG) project. K.C. would like to thank the UICC International Cancer Technology Transfer Fellowship program; G.V. is grateful to Cancer Research United Kingdom for financial support. We thank Jane Blazeby, Penny Wright, and Jane Maher for advice regarding the patient interviews.",
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T1 - Evidence-based guidelines for determination of sample size and interpretation of the European Organisation for the Research and Treatment of Cancer quality of life questionnaire core 30 (EORTC QLQ-C30)

AU - Cocks, Kim

AU - King, Madeleine T.

AU - Velikova, Galina

AU - Martyn St-James, Marrissa

AU - Fayers, Peter

AU - Brown, Julia M.

N1 - Acknowledgment We thank Cancer Research United Kingdom for funding for the Evidence-Based Interpretation Guidelines (EBIG) project. K.C. would like to thank the UICC International Cancer Technology Transfer Fellowship program; G.V. is grateful to Cancer Research United Kingdom for financial support. We thank Jane Blazeby, Penny Wright, and Jane Maher for advice regarding the patient interviews.

PY - 2011/1/1

Y1 - 2011/1/1

N2 - PurposeTo use published literature to estimate large, medium, and small differences in quality of life (QOL) data from the European Organisation for the Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30).MethodsAn innovative method combining systematic review of published studies, expert opinions, and meta-analysis was used to estimate large, medium, and small differences for QLQ-C30 scores. Published mean data were identified from the literature. Differences (contrasts) between groups (eg, between treatment groups, age groups, and performance status groups) were reviewed by 34 experts in QOL measurement and cancer treatment. The experts, blinded to actual QOL results, were asked to predict these differences. A large difference was defined as one representing unequivocal clinical relevance. A medium difference was defined as likely to be clinically relevant but to a lesser extent. A small difference was one believed to be subtle but nevertheless clinically relevant. A trivial difference was used to describe circumstances unlikely to have any clinical relevance. Actual QOL results were combined using meta-analytic techniques to estimate differences corresponding to small, medium, or large effects.ResultsNine hundred eleven articles were identified, leading to 152 relevant articles (2,217 contrasts) being reviewed by at least two experts. Resulting estimates from the meta-analysis varied depending on the subscale. Thus, the recommended minimum to detect medium differences ranges from 9 (cognitive functioning) to 19 points (role functioning).ConclusionGuidelines for the size of effects are provided for the QLQ-C30 subscales. These guidelines can be used for sample size calculations for clinical trials and can also be used to aid interpretation of differences in QLQ-C30 scores

AB - PurposeTo use published literature to estimate large, medium, and small differences in quality of life (QOL) data from the European Organisation for the Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30).MethodsAn innovative method combining systematic review of published studies, expert opinions, and meta-analysis was used to estimate large, medium, and small differences for QLQ-C30 scores. Published mean data were identified from the literature. Differences (contrasts) between groups (eg, between treatment groups, age groups, and performance status groups) were reviewed by 34 experts in QOL measurement and cancer treatment. The experts, blinded to actual QOL results, were asked to predict these differences. A large difference was defined as one representing unequivocal clinical relevance. A medium difference was defined as likely to be clinically relevant but to a lesser extent. A small difference was one believed to be subtle but nevertheless clinically relevant. A trivial difference was used to describe circumstances unlikely to have any clinical relevance. Actual QOL results were combined using meta-analytic techniques to estimate differences corresponding to small, medium, or large effects.ResultsNine hundred eleven articles were identified, leading to 152 relevant articles (2,217 contrasts) being reviewed by at least two experts. Resulting estimates from the meta-analysis varied depending on the subscale. Thus, the recommended minimum to detect medium differences ranges from 9 (cognitive functioning) to 19 points (role functioning).ConclusionGuidelines for the size of effects are provided for the QLQ-C30 subscales. These guidelines can be used for sample size calculations for clinical trials and can also be used to aid interpretation of differences in QLQ-C30 scores

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JF - Journal of Clinical Oncology

SN - 0732-183X

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ER -