Coverage of symptomatic toxicities from the common terminology criteria for adverse events (CTCAE) framework within the european organization for research and treatment of cancer (EORTC) item library.
Authors: Piccinin Claire , Bottomley Andrew , Velikova Galina , Groenvold Mogens , Kuliś Dagmara , Blazeby Jane M. , Gilbert Alexandra 
Published: June 2021

e24117

Background: The EORTC Item Library is an online, interactive platform comprised of 950 distinct questions (items) from 67 different EORTC patient-reported outcome (PRO) questionnaires, covering a range of symptomatic toxicities, types of functioning, and impact on quality of life. These PROs provide a patient-centred perspective, complementing clinician adverse event (AE) reporting using classifications like the CTCAE. In order to summarize the coverage of symptomatic toxicities and facilitate the identification of items through use of a standardized framework, a mapping study was carried out, aimed at creating a coding system to classify EORTC items according to the CTCAE and link them to corresponding AEs. Methods: All items were searched for within the CTCAE (v5.0) using a deductive approach. Items were coded as linked if they were described within an AE’s title, description, or grading. Items not suitable for CTCAE coding were inductively assigned a descriptive classification. Descriptive classifications were also applied along with CTCAE codes when they provided additional information. Symptoms described in EORTC items but not located in the CTCAE were coded as missing and additional codes were assigned to highlight EORTC items capturing multiple underlying issues and diagnosis only CTCAE codes. Two raters independently coded 249 items and agreement was calculated. The remaining 701 items were coded by one rater and verified by the second, with a third introduced to discuss any discrepancies until a consensus was reached. Results: Agreement for raters following independent coding was 77.9% for at least one AE per item. In total, 625 (65.8%) items were linked to 208 different AEs. Fatigue was the most commonly linked AE, representing 4.9% of linked AEs. The majority of linked items were associated with one (65.6%) or two (23.5%) AEs, with some linked to three or more (10.9%). Multiple linkage resulted from different symptoms relating to the same issue/diagnosis or one symptom relating to multiple diagnoses. Two symptoms captured by six EORTC items but not found in the CTCAE were identified: bowel urgency and tenesmus. Seven descriptive non-CTCAE classifications emerged, with most of these covering the emotional impact of symptom, diagnosis, or treatment (33.6%) and information/satisfaction with care (31.7%). Nineteen items (2%) were linked to multiple underlying issues, and 43 (4.5%) to diagnosis only CTCAE codes. Conclusions: The EORTC Item Library provides extensive coverage of CTCAE symptomatic toxicities, along with other issues that are important to cancer patients, including emotional well-being and satisfaction with care services. Classifying symptomatic PRO items following the CTCAE clinical framework may facilitate future PRO selection and use in clinical trials and routine care.