Minimally important differences for interpreting EORTC QLQ-C30 change scores over time: A synthesis across 21 clinical trials involving nine different cancer types

Jammbe Z Musoro; Corneel Coens; Mirjam A G Sprangers; Yvonne Brandberg; Mogens Groenvold; Hans-Henning Flechtner; Kim Cocks; Galina Velikova; Linda Dirven; Elfriede Greimel; Susanne Singer; Katarzyna Pogoda; Eva M Gamper; Samantha C Sodergren; Alexander Eggermont; Michael Koller; Jaap C Reijneveld; Martin J B Taphoorn; Madeleine T King; Andrew Bottomley; EORTC Melanoma, Breast, Head and Neck, Genito-urinary, Gynecological, Gastro-intestinal, Brain, Lung and Quality of Life Groups

doi:10.1016/j.ejca.2023.04.027

Minimally important differences for interpreting EORTC QLQ-C30 change scores over time: A synthesis across 21 clinical trials involving nine different cancer types

Eur J Cancer. 2023 Jul:188:171-182. doi: 10.1016/j.ejca.2023.04.027. Epub 2023 May 7.

Authors

Jammbe Z Musoro¹, Corneel Coens², Mirjam A G Sprangers³, Yvonne Brandberg⁴, Mogens Groenvold⁵, Hans-Henning Flechtner⁶, Kim Cocks⁷, Galina Velikova⁸, Linda Dirven⁹, Elfriede Greimel¹⁰, Susanne Singer¹¹, Katarzyna Pogoda¹², Eva M Gamper¹³, Samantha C Sodergren¹⁴, Alexander Eggermont¹⁵, Michael Koller¹⁶, Jaap C Reijneveld¹⁷, Martin J B Taphoorn⁹, Madeleine T King¹⁸, Andrew Bottomley²; EORTC Melanoma, Breast, Head and Neck, Genito-urinary, Gynecological, Gastro-intestinal, Brain, Lung and Quality of Life Groups

Affiliations

¹ European Organisation for Research and Treatment of Cancer (EORTC), Brussels, Belgium. Electronic address: jammbe.musoro@eortc.org.
² European Organisation for Research and Treatment of Cancer (EORTC), Brussels, Belgium.
³ Amsterdam UMC Location University of Amsterdam, Medical Psychology, Amsterdam, The Netherlands; Cancer Center Amsterdam, Cancer Treatment and Quality of Life, Amsterdam, The Netherlands.
⁴ Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden.
⁵ Department of Public Health, University of Copenhagen, and Bispebjerg Hospital, Copenhagen, Denmark.
⁶ Clinic for Child and Adolescent Psychiatry and Psychotherapy, University of Magdeburg, Magdeburg, Germany.
⁷ Adelphi Values, Bollington, Cheshire, UK.
⁸ Leeds Institute of Medical Research at St James's, University of Leeds, St James's University Hospital, Leeds, UK; Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, St James's University Hospital, Leeds, UK.
⁹ Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands; Department of Neurology, Haaglanden Medical Center, The Hague, The Netherlands.
¹⁰ Medical University Graz, Graz, Austria.
¹¹ Institute of Medical Biostatistics, Epidemiology and Informatics, Division of Epidemiology and Health Services Research, University Medical Centre Mainz, Germany; University Cancer Centre Mainz, Germany.
¹² Departmenf of Breast Cancer and Reconstructive Surgery, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland.
¹³ Innsbruck Institute of Patient-centered Outcome Research (IIPCOR), Innsbruck, Austria.
¹⁴ School of Health Sciences, University of Southampton, Southampton, UK.
¹⁵ Princess Máxima Center, Utrecht and University Medical Center Utrecht, The Netherlands; Comprehensive Cancer Center Munich, Technical University Munich & Ludwig Maximiliaan University, Munich, Germany.
¹⁶ Center for Clinical Studies, University Hospital Regensburg, Regensburg, Germany.
¹⁷ Amsterdam University Medical Centers, location VU University Medical Center, Department of Neurology Brain Tumor Center, Amsterdam, The Netherlands.
¹⁸ University of Sydney, Faculty of Science, School of Psychology, Sydney, NSW, Australia.

PMID: 37257278
DOI: 10.1016/j.ejca.2023.04.027

Abstract

Introduction: Early guidelines for minimally important differences (MIDs) for the EORTC QLQ-C30 proposed ≥10 points change as clinically meaningful for all scales. Increasing evidence that MIDs can vary by scale, direction of change, cancer type and estimation method has raised doubt about a single global standard. This paper identifies MID patterns for interpreting group-level change in EORTC QLQ-C30 scores across nine cancer types.

Methods: Data were obtained from 21 published EORTC Phase III trials that enroled 13,015 patients across nine cancer types (brain, colorectal, advanced breast, head/neck, lung, mesothelioma, melanoma, ovarian, and prostate). Anchor-based MIDs for within-group change and between-group differences in change over time were obtained via mean change method and linear regression, respectively. Separate MIDs were estimated for improvements and deteriorations. Distribution-based estimates were derived and compared with anchor-based MIDs.

Results: Anchor-based MIDs mostly ranged from 5 to 10 points. Differences in MIDs for improvement vs deterioration, for both within-group and between-group, were mostly within a 2-points range. Larger differences between within-group and between-group MIDs were observed for several scales in ovarian, lung and head/neck cancer. Most anchor-based MIDs ranged between 0.3 SD and 0.5 SD distribution-based estimates.

Conclusions: Our results reinforce recent claims that no single MID can be applied to all EORTC QLQ-C30 scales and disease settings. MIDs varied by scale, improvement/deterioration, within/between comparisons and by cancer type. Researchers applying commonly used rules of thumb must be aware of the risk of dismissing changes that are clinically meaningful or underpowering analyses when smaller MIDs apply.

Keywords: Cancer; EORTC QLQ-C30; Group-level change; Health-related quality of life (HRQoL); Minimally important difference (MID); Patient-reported outcomes (PRO).

Publication types

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

MeSH terms

Breast
Head and Neck Neoplasms*
Humans
Male
Melanoma*
Mesothelioma*
Quality of Life
Surveys and Questionnaires