The updated QLG strategy: core +/- module +/- Item Library

Development and validation of a quality of life measure takes a long time. Thorough testing ensures validity and reliability, but requires resources and time. In order to answer the needs of clinical research and build on what the Quality of Life Group has already developed and tested, the Item Library was created, offering researchers new possibilities.

In the past, the standard model of use was the core + module, which involved use of the QLQ-C30 supplemented with a disease-, site-, or population-specific module from the EORTC’s portfolio. However, as cancer therapies evolved, it became evident that a given module might not include problems and symptoms of novel treatments that were not common when the questionnaire was initially being developed. Moreover, for some populations (e.g., rare disease groups) there was not always a corresponding module and the need to be flexible and pragmatic (e.g., considering issues like patient burden) was also acknowledged.

With the updated strategy, these missing symptoms or problems can be measured using an item list created with the help of the Item Library. This means that the current model is based on the core +/- module +/- item list, which includes items (questions) from the Item Library. This new strategy offers users much more flexibility by allowing them to capture a wider range of symptoms and events, which in turn makes it easier for patients to describe their experiences more fully.

What is it?

The Item Library was originally created as a database of all the EORTC quality of life items and their translations, so that QLG members could easily consult the existing items and see how they were worded, when working on new questionnaires. This was intended to reduce some of the burden associated with questionnaire construction and also ensure a high degree of consistency across different measures. After it became clear that static questionnaires might not always be sufficient to meet the demands of quickly evolving treatment modalities, the database – then, the Item Bank – began to shift into its new role as the Item Library, an integrated and dynamic tool which is accessible to users from academia and industry.

In its current form, the Item Library is an online platform comprised of more than 1,000 individual items from over 70 EORTC measures (Phase 3 completed, following the EORTC QLG Module Development Guidelines), some of which have been translated into over 120 languages. Detailed information about items and instruments (including phase, translations, scales, publications, and similar items) is provided to facilitate usability and help users during different stages of their research. Items are also classified using different systems, including a general EORTC taxonomy along with the CTCAE framework, to help users find items using more general terms and a common clinical language.

How does it work?

Once you have obtained access to the Item Library (after requesting it here), you will be able to browse through existing measures (both official EORTC instruments and other custom-made item lists) and use a variety of keywords to search for items. Search results can then be filtered to allow you to narrow them down to what you need. Additional information provided for each item, for example on available translations and recommended wording, can also be used to help build the custom-made lists. Items can also be searched for using the different classification systems.

By making the custom-made item lists available to all registered users, the Item Library promotes accessibility and collaboration across the research community, with the goal of creating tools that support the advancement of patient reported outcomes measures in oncology.

How is it used?

In addition to creating item lists, the Item Library can also assist with the following:

  • Storing information about the development of module items, including the wording and translations of the various items and subscales
  • Searching for items based on common clinical frameworks (e.g., the CTCAE)
  • Comparing items and scales in new modules and item lists with those that are already approved
  • Promoting collaboration between users with similar research interests
  • Highlighting areas for new item/questionnaire development

Key references*

  • The Item Library within the updated QLG measurement strategy
    • Kuliś D, Bottomley A, Whittaker C, van de Poll-France LV, Darlington A, Holzner, B, Koller M, Reijneveld JC, Tomaszewski K, & Grønvold M. The Use of the EORTC Item Library to Supplement EORTC Quality of Life Instruments. Value in Health, 2017, 20.9: PA775. https://doi.org/10.1016/j.jval.2017.08.2236
  • Guidelines for using the Item Library
    • Kuliś D, Piccinin C, Bottomley A, & Grønvold M. on behalf of the EORTC Quality of Life Group. EORTC Quality of Life Group Item Library: Technical Guidelines. 1st ed. Brussels: EORTC; 2018. Available from: https://qol.eortc.org/manuals/
    • Piccinin C, Kuliś D, Bottomley A, Bjordal K, Coens C, Darlington AS, Johnson C, Velikova G, & Groenvold M. on behalf of the EORTC Quality of Life Group. EORTC Quality of Life Group Item Library User Guidelines. 1st ed. Brussels: EORTC; 2022. Available from: https://qol.eortc.org/manuals/
    • Piccinin C, Basch E, Bhatnagar V, Calvert M, Campbell A, Cella D, Cleeland CS, Coens C, Darlington A-S, Dueck AC, Groenvold M, Herold R, King-Kallimanis BL, Kluetz PG, Kuliś D, O’Connor D, Oliver K, Pe M, Reeve BB, Reijneveld JC, Wang XS, & Bottomley A. Recommendations on the use of item libraries for patient-reported outcome measurement in oncology trials: Findings from an international, multidisciplinary working group. The Lancet Oncology, 2023, 24.2: e86-e95. https://doi.org/10.1016/s1470-2045(22)00654-4
  • Classification of Item Library content
    • Gilbert A*, Piccinin C*, Velikova G, Groenvold M, Kuliś D, Blazeby J, Bottomley A. Linking the European Organisation for Research and Treatment of Cancer (EORTC) Item Library to the Common Terminology Criteria for Adverse Events (CTCAE). Journal of Clinical Oncology, 2022, 40.32: 3770-3780. https://doi.org/10.1200/jco.21.02017

* When referring to the Item Library’s online platform, kindly also include the URL in your citations.

Questions about Item Library use and access can be sent here.