Investigating the equivalence of the EORTC QLQ-C30 and the QLQ-F17 (Equivalence C30/F17)
Project summary
Regulatory bodies and many users advocate for shorter questionnaires that minimize patient burden while still capturing all relevant information in a given clinical context. In response to this need, the EORTC Quality of Life Group (QLG) developed the QLQ-F17, a concise version of the widely used EORTC QLQ-C30. The QLQ-F17 includes only the functioning scales of the QLQ-C30 and is designed to be complemented by symptom-specific items or modules from the EORTC Item Library. This approach supports a flexible, efficient, and patient-centered strategy for assessing quality of life in cancer clinical trials and routine care.
To validate this new instrument, the EORTC QLG conducted a comprehensive study comparing the established QLQ-C30 with the new QLQ-F17. The main objective was to evaluate whether the QLQ-F17 produces results equivalent to the functional scales of the QLQ-C30 while maintaining the same high psychometric standards.
The analyses demonstrated full equivalence between the QLQ-F17 and the QLQ-C30 for all functional domains, including the Global Health Status/Quality of Life scale. Psychometric properties such as reliability, internal consistency, and measurement precision were highly comparable between both instruments.
Based on these findings, the QLQ-F17 can now be used as a core questionnaire within the EORTC portfolio when the focus is solely on functioning. Its modular structure allows for tailored, time-efficient, and scientifically robust assessment strategies that align with modern multimodality cancer care and the evolving expectations of regulatory authorities.
Achievements
See publications below
Future plans
This study is closed
For patients
EORTC Core Questionnaire (QLQ-C30) is composed of questions relating to somatic symptoms (e.g. pain) or functioning (e.g. physical abilities) and is widely used in cancer clinical studies. A shortened version of this questionnaire contains only the 17 functioning items and is therefore call F17. The purpose of this project is to investigate whether the two questionnaires possess equivalent measurement properties and arrive at the same score values.
Publications
| Output of the project | Deliverables* |
| Main outcome: | |
| The main objective of this project is to provide evidence that would enable us to conclude that the C30 and F17 are equivalent in the sense of yielding identical measurement results as well as possessing identical psychometric properties. | Zeman F, Giesinger JM, Pukrop T, Petersen MA, Groenvold M, Nolte S, Kuliś D, Shrestha S, Leysen L, Cocks K, Coens C, Ioannidis G, Pompili C, Koller M; of the EORTC QLG. The EORTC QLQ-F17 as a shortened version of the EORTC QLQ-C30 to assess self-reported functioning in cancer patients: investigating equivalence and psychometric properties in a randomized cross-over trial. EClinicalMedicine. 2025 Jun 3;84:103262. doi: 10.1016/j.eclinm.2025.103262. PMID: 40521164; PMCID: PMC12167450. |
| Secondary outcome(s), if applicable: | |
| Secondary aims are investigating order effects and yielding additional reference data. | Outside the original project as funded by the EORTC QLG
In progress |