EORTC QLQ-C30 Development
A first generation of the core questionnaire, the EORTC Quality of Life Questionnaire-Core 36 (EORTC QLQ-C36) was developed in 1987 (Aaronson N.K., Ahmedzai S., Bullinger M. et al: The EORTC core quality of life questionnaire: Interim results of an international field study. In: Osoba D. ed. Effect of Cancer on Quality of Life. Boca Raton, FL: CRC Press 1991: 185-203.
The EORTC QLQ-C36 questionnaire was designed to be:
- cancer specific,
- multidimensional in structure,
- appropriate for self-administration, and
- applicable across a range of cultural settings.
The subsequent versions of the core questionnaire were EORTC QLQ-C30 (version 1.0), EORTC QLQ-C30 (+3), EORTC QLQ-C30 (version 2.0) and EORTC QLQ-C30 (version 3.0).
The EORTC QLQ-C30 (version 3.0) is the most recent version. It has been in use since December 1997 and should be used for all new studies. A specimen of the EORTC QLQ-C30 is available here. The conditions for its use are defined in the QOL Department activities.
Computerized adaptive testing (CAT)
Traditional paper and pencil questionnaires such as the EORTC QLQ-C30, where all patients are asked the same questions, do not take advantage of the information that can be obtained from a patient's previous answers. Furthermore, such brief scales have limitations with regard to measurement precision.
Therefore, the QLG has initiated a project to develop computerized adaptive testing (CAT) for the aspects of QOL measured with the EORTC QLQ-C30. With CAT measurement the questionnaire is adapted to the individual. CAT has several advantages including increased precision and increased flexibility to tailor the questionnaire to each study.
Further details about the EORTC QLG CAT-project are available here.
Module Development
While the EORTC QLQ-C30 is an important tool to assess the generic aspects of QOL, it has limitations and therefore a modular approach was adopted for disease specific treatment measurements.
An essential aspect of the "modular" approach to QOL assessment adopted by the EORTC QLG is the development of modules specific to tumor site, treatment modality, or a QOL dimension, to be administered in addition to the core questionnaire (i.e. the EORTC QLQ-C30). The modules, like the core questionnaire, are designed for use in cancer clinical trials.
The validated modules at present are the Lung (LC13), Breast (BR23), Head & Neck (H&N35), Ovarian (OV28), Oesophageal (OES18), Gastric (STO22), Multiple Myeloma (MY20), Cervix (CX24), Oesophago-gastric (OG25) and Prostate (PR25) modules.
The QLG has also developed two other stand alone questionnaires, one to assess Patient Satisfaction (EORTC IN-PATSAT32) and a short form questionnaire for palliative care patients (EORTC QLQ-C15-PAL).
Since individual members or subgroups of the QLG are involved in module development, guidelines are needed and these have been developed to standardize the module development process. This ensures uniformly high quality across modules.
The term "module" is defined, the composition of modules is sketched, the attributes of modules are specified and the module development process is described in detail in the "Guidelines for Developing Questionnaire Modules"
Translations
The translation of the core questionnaire (EORTC QLQ-C30) and modules into other languages follows a procedure that has been documented in detail (EORTC Translation Procedure, Cull et al., 2002).
Any modules not initially developed in English are first translated into English and then into other languages.
All translations involve two native speakers of the target language who are also fluent in the original language; they independently translate the questionnaire. The resulting translation is then "back translated" by two independent native speakers of the original language, with iterations between the forward and backward translation as necessary. There is then a pilot-test of the translated questionnaire. A formal report is submitted to the QLG, and this is reviewed by at least two members before approval is given.
Field studies
The following field studies have been performed:
15861
Development of core questionnaire and lung module in lung cancer patients Publication: The European Organization for Research and Treatment of Cancer QLQ-C30: A Quality-of-Life Instrument for use in international clinical trials in oncology. N.K. Aaronson et al, J. of National Cancer Institute, Vol 85, N° 5, March 1993.
15931
An international field study of the reliability and validity of the EORTC QLQ-C30 (version 3.0) and a disease-specific questionnaire module (the QLQ-BR23) in assessing the quality of life of patients with breast cancer. Study coordinator: N.K. Aaronson
15941
An international field study of the reliability and validity of the EORTC QLQ-C30 (version 3.0) and a disease-specific questionnaire module (the QLQ-H&N35) in assessing the quality of life of patients with head and neck cancer. Study coordinator: K. Bjordal
15961
An international field study of the reliability and validity of the EORTC QLQ-C30 (version 3.0) and a disease-specific questionnaire module (the QLQ-OES24) in assessing the quality of life of patients with oesophageal cancer. Study coordinator: J. Blazeby Eur. J. Cancer Jul; 39(10):1384-94; 2003.
15982
An international field study of the reliability and validity of the EORTC QLQ-C30 (version 3.0) and a disease-specific questionnaire module (the QLQ-OV28) in assessing the quality of life of patients with ovarian cancer. Study coordinator: A. Cull Eur. J. Cancer Jul; 39(10):1402-8; 2003.
15001
An international field study of the reliability and validity of the EORTC QLQ-C30 (version 3.0) and a disease-specific questionnaire module (the QLQ-STO22) in assessing the quality of life of patients with gastric cancer. Study coordinator: J. Blazeby Eur. J Cancer 40:2260-68; 2004.
15012
An international field study of the EORTC in Patient Satisfaction with Care measure (IN-PATSAT32). Study coordinator: A. Brédart
15011/30011
An international field study of the EORTC in patients with prostate cancer (PR25). Study coordinator: N.K. Aaronson
Clinical trials
The fundamental structure of the EORTC is based upon disease oriented groups which develop their clinical research through the direct input of their participating scientists. Research is accomplished mainly through the execution of large, prospective, randomized, multinational cancer clinical trials.
More than 2,000 clinicians located in 350 medical institutions in 35 countries participate in EORTC protocols. Each year thousands of patients are entered into ongoing studies.
Although there are many treatment cooperative groups in the EORTC, not all of them have included QOL as an outcome measure in their trials. However, some groups have long-standing experience in QOL assessments.
The Quality of Life Department (QOL Department) is involved in a wide range of studies, across most of the EORTC Cooperative Groups, through all phases, from the design, to the analysis and publication of the results.
Manuals
As QOL research has become increasingly important the QLG has become concerned that high quality information regarding its assessment and use in clinical trials is available. This has been facilitated by the publication of several manuals as "blue books". All the manuals can be found on the QLQ-C30 Reference Values CD Rom.