The standard EORTC QoL questionnaire requires the patient to complete his or her initials and birthday. Is this necessary?

No, this information is not needed per se. It is not part of the actual HRQoL outcomes. Besides, certain authorities and/or ethical committees consider that this info is part of patient’s privacy and should not be collected. So this question may be omitted or modified. However, be aware that in most studies one will need an unambiguous method of matching a person’s questionnaire with other relevant study data. Many regulatory bodies (e.g. The World Medical Association’s Declaration of Helsinki, International Conference on Harmonization (ICH), Good Clinical Practice (GCP) and EU Clinical Trials Directive guidelines) require that a study subject’s right to data protection and privacy must be safeguarded in the context of a clinical study. This usually implies that the names of the study participants cannot be collected since these must remain anonymous to the study investigators handling the data. If you are unsure which privacy data you can or cannot collect, please check with your local or national governing Ethical Committee for guidance.

Can my patients use an electronic means or a telephone based system to complete the questionnaires?

Yes. Your patients can use these types of systems for questionnaire completion, as equivalency of derived scores is considered sufficient. You can distribute the questionnaires via an electronic means e.g. on touch screen computers or via the web. You can also use Interactive Voice Response systems (i.e. telephone.) There is a statement to this effect in both the academic and commercial users’ agreement. But please be aware that there may be additional fees to pay. The EORTC QLG still expects to receive their royalty fee (from commercial users only) in addition to any fee you may have to pay for use of proprietary software.

Recently, an online platform (CHES) was established to provide electronic data collection infrastructure for projects conducted by the EORTC Quality of Life Group. The software company ESD – Evaluation Software Development (www.ches.pro) has developed this platform also for the demonstration and implementation of CHES in daily oncology practice when using EORTC QLQ measures. CHES allows questionnaire administration, sophisticated graphical presentation of questionnaire results as well as the completion of electronic case report forms. The CHES platform can be used in all common web-browsers and does not require any local software installation. The software complies with the Good clinical practice guidelines (GCP) for electronic data collection. For more info: https://ches.eortc.be/cms/ and for details please contact the principal investigator: Bernhard Holzner Department of Psychiatry and Psychotherapy Innsbruck Medical University, Anichstr. 35, 6020 Innsbruck, AUSTRIA bernhard.holzner@uki.at.

If you use electronic data capture there are specific confidentiality and security concerns. It is your responsibility to check that your system complies with any regulations in the countries where you are collecting data.

We would like to define the minimal clinically important differences (MID) for improvement and deterioration a quality of life module

There are no specific guidelines for selecting MIDs for the modules. For more information, it might be helpful to contact the lead developer of the specific module via the questionnaires page on our website.

How do I interpret the score of a patient?

The thresholds for interpreting clinically meaningful change in QoL scores between groups of patients (see FAQ:  How do I interpret QoL scores?) are also often used to interpret individual level score change clinically meaningful. For instance, a patient who changes by the MID or more can be considered to be a ‘responder’.

The proportion of responders can be compared between groups (e.g. between two treatment arms).


However, note that MIDs for interpreting group-level change might be insufficiently precise for monitoring individual patients because individuals can only change by specific points (jumps) in their QoL scores. It is important to investigate whether individual-level change can be interpreted as “real change”, and that it is not just an artifact of measurement error. Please see the reference below for more details.


  • Ref: King MT. A point of minimal important difference (MID): a critique of terminology and methods. Expert Rev Pharmacoecon Outcome Res. 2011 Apr; 11(2):171-84.)


Giesinger et al (Health Qual Life Outcomes, 2016) have established thresholds for clinical importance for four EORTC QLQ-C30 scales: Physical Functioning (PF), Emotional Functioning (EF), Pain (PA) and Fatigue (FA). These thresholds are useful for screening of individual patients with clinically important problems requiring further exploration and possibly intervention by health care professionals in daily clinical practice.

How do I interpret QoL scores?

The QLQ-C30 and its modules have been designed to evaluate change of HRQoL in clinical trials setting. Therefore the scores are mainly used in a comparative setting such as:

  • comparing different patient groups at a given time point
  • comparing changes within one group over time
  • comparing changes over time between different patient groups.

When comparing scores, it is important keep in mind that statistically significant differences do not necessarily imply clinically relevant differences or changes and vice versa.


A minimum important difference (MID) of 5 to 10 points, as defined by Osoba et al (J Clin Oncol 1998), is generally recommended for interpreting group differences and changes in the EORTC QLQ-C30 scale scores as clinically meaningful. The rationale for using MIDs of 5 to 10 points has been supported in several papers, specific for the QLQ-C30. Of note is the paper by King et al (Qual Res 1996) where known-group comparisons were used to establish a between group difference.

However, note that more recent guidelines have highlighted that the 5 to 10 points rule may be too simplistic in that it does not differentiate between the QLQ-C30 scales, between directions of change (improvement vs deterioration), and may not be achievable in all settings (Cocks et al J; Clin Oncol 2010,  and Cocks et al; EJC 2012). Below are some additional useful references that should also be consulted when selecting clinically meaningful thresholds for group differences and changes across the different QLQ-C30 scales, for improving and deteriorating scores, and in different disease settings.

  • Cocks K, et al. 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. J Clin Oncol 2010; 29(1): 89–96.
  • Cocks K, et al. Evidence-based guidelines for interpreting change scores for the European Organisation for the Research and Treatment of Cancer Quality of Life Questionnaire Core 30. European Journal of Cancer (2012) 48, 1713– 1721.
  • Maringwa JT, et al. on behalf of the EORTC PROBE project and the Lung Cancer Group. Minimal important differences for interpreting health-related quality of life scores from the EORTC QLQ-C30 in lung cancer patients participating in randomized controlled trials. Support Care Cancer. 2011 Nov; 19(11):1753-60.
  • Maringwa J, et al. Minimal Clinically Meaningful Differences for the EORTC QLQ-C30 and EORTC QLQ-BN20 Scales in Brain Cancer Patients. Ann Oncol. 2011 Sep; 22(9):2107-12.

I read a paper which provided mean scores for the functional and symptom scales. What are these values scored out of? (i.e. what is considered optimal /maximal?) Is a lower score a worse quality of life?

The EORTC QLQ-C30 comprises 30 items (i.e. single questions), 24 of which are aggregated into nine multi-item scales, that is, five functioning scales (physical, role, cognitive, emotional and social), three symptom scales (fatigue, pain and nausea/vomiting) and one global health status scale. The remaining six single-item (dyspnoea, appetite loss, sleep disturbance, constipation, diarrhoea and the financial impact) scales assess symptoms. No item occurs in more than one scale.


Scoring of the QLQ-C30 is performed according to QLQ-C30 Scoring manual, which is available to download via our website on the manuals page. All of the scales and single-item measures range in score from 0 to 100. Higher score for the functioning scales and global health status denote a better level of functioning (i.e. a better state of the patient), while higher scores on the symptom and single-item scales indicate a higher level of symptoms (i.e. a worse state of the patient).


Note: Some authors may reverse the symptom scores to follow the functioning scales interpretation (and vice versa). The reason for this is usually for consistency in signs of the change scores across the various scales. Care should be taken when interpreting the change scores in such scenarios.

I do not want to include all items. Can I use single items of a module?

Yes, you can use single items/scales from different modules. With the EORTC Item Library, you can make an item list that can be used in conjunction with the QLQ-C30 and an existing validated module, to cover missing issues that you want to assess.

Can we change the order of the items?

The order of the items in a validated questionnaire cannot be changed. The questionnaire has been developed and validated in this format, and changing the order of the items might affect the psychometric properties of the questionnaire.

Can I add some items? (e.g. I need some questions related to coping)

Yes, with the EORTC Item Library you can make an item list, adding items to an existing questionnaire if you think that important domains or symptoms might be missing.

Can I modify questions or alter the time scale?

No, it is not possible to modify the wording of questions or to alter the time scale, if you want to use a validated questionnaire and preserve its psychometric qualities. When creating an item list using the Item Library, you can select which time scale you’d like to use for the items in question, but the wording of the item can never be altered.

Is there a short version of the QLQ-C30?

A short version of the questionnaire is not available. However, the EORTC is considering this presently and may, in the future, develop a shorter version focused on the functional scales. In addition, a short form for use in palliative care, the QLQ-C15-PAL is available as a validated measure, based on items from the QLQ-C30. Please see our questionnaires page.

Can I use the module without the core questionnaire (QLQ-C30)?

The module has been designed to be used in conjunction with the core questionnaire, and the content validity is based upon this combination. The core questionnaire covers important generic cancer symptoms and side effects which could be missed if only the module alone is used. As such, we strongly recommend using the module in conjunction with the core questionnaire.

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