Systematic review of patient-reported outcome item libraries in cancer research: an EORTC Quality of Life Group study

Background Patient-reported outcome (PRO) item libraries support flexible PRO assessment in cancer research by facilitating the development of customized item lists. However, little is known about the use of item lists in clinical research. This systematic review addresses this by assessing utilization of PRO item libraries and lists in oncology research.

Methods A systematic review of MEDLINE, Embase, and CINAHL identified cancer studies using PRO item libraries to develop item lists, regardless of study design, published between October 2021 and September 2025. Key features of item library usage were extracted and analyzed descriptively.

Results A total of 78 studies were included (25 trials and feasibility, 53 observational). The Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events system was frequently used (49 of 78), and symptom assessment was the most common application (63 of 78). Item lists were implemented across different settings including novel treatments (19 of 78) and rare cancers (15 of 78). Most item lists were derived from a single PRO item library (72 of 78). In some studies, there was additional customization such as item wording changes (5 of 78) or addition of items adapted from the item library (9 of 78). Item selection methods included literature (32 of 78), patient involvement (8 of 78) and consultation with health-care professionals (11 of 78). Many studies (40 of 78) did not report methods used.

Conclusions PRO item libraries are increasingly used to create customized item lists in oncology research, primarily for symptom assessment. However, reporting practices for methods used are inconsistent, highlighting the need for standardized guidelines for reporting PRO item lists in clinical trials and routine care to improve transparency, reproducibility, and quality.