Comparison of EORTC QLQ-C30 and PRO-CTCAE™ Questionnaires on Six Symptom Items

Clinical studies have over the past decade paid increasing attention to health-related quality of life data. Multiple questionnaires are often administered resulting in overlapping questions increasing patient burden.

To examine the correlations between the commonly used European Organization for Research and Treatment of Cancer Quality of Life Questionnnaire-C30 (QLQ-C30) and the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE™) on six coinciding items to determine consistency between overlapping items.

Data were prospectively collected from patients attending two cancer centers in the U.K. Participants completed the QLQ-C30 version 3.0 every four weeks and the PRO-CTCAE at least once a week for 12 weeks. Data were collected via the Internet or an interactive voice response. For the six coinciding items in QLQ-C30 and PRO-CTCAE: pain, nausea, vomiting, constipation, diarrhea, and fatigue, comparisons were made between all possible related responses by aligning the four responses in the QLQ-C30 with two condensed versions of the five responses in the PRO-CTCAE. Consistency and reliability was determined with the intraclass correlation coefficient (ICC) and Cronbach's α.

About 247 patients completed 785 QLQ-C30 and 2501 PRO-CTCAE questionnaires. Moderate (ICC >0.5) to good (ICC >0.75) reliability and Cronbach's α >0.7 were found on all coinciding questions except for questions concerning the severity of nausea and vomiting as a result of relatively few patients responding to these questions. Items on frequency showed better correlations than the severity and interference items.

The good reliability and consistency between the QLQ-C30 and PRO-CTCAE support future attempts to minimize patient burden by shortening health-related quality of life questionnaires.