The Japanese version of the national cancer institute’s patient-reported outcomes version of the common terminology criteria for adverse events (Pro-CTCAE): Psychometric validation and discordance between clinician and patient assessments of adverse events

Background: The Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) was developed by the National Cancer Institute as an adverse event assessment system to evaluate patients’ symptoms, which tend to be underestimated in cancer clinical trials. The aim of this study was to assess the psychometric properties of the Japanese version of the PRO-CTCAE and the degree of adverse event assessment discordance between clinicians and patients. Methods: A total of 187 cancer patients receiving systemic therapy were enrolled. Reproducibility, criterion validity, and responsiveness of the Japanese version of PROCTCAE were assessed. The EORTC QLQ-C30 was used as an external anchor. Discordance of assessment of adverse events between clinician and patients were also assessed using the CTCAE and PRO-CTCAE. Results: A total of 187 participants (187 for criterion validity, 80 for reproducibility, and 100 for responsiveness), were analyzed (Mage = 62.4 years). All patients responded to at least one symptom item (M = 16). The mean (SD) intra-class correlation coefficients of overall reproducibility for the Japanese PRO-CTCAE was 0.63 (0.02). The correlation coefficient for the corresponding items in the EORTC QLQ-C30 and the Japanese PRO-CTCAE was high (Pearson r =0.56–0.76). The analysis of responsiveness revealed significant dose-response trends (Jonckheere-Terpstra test, ps < 0.001). Depending on the adverse events, a discrepancy was observed in evaluation between the clinician and patient. Conclusions: These results revealed that there is underestimation in the assessment of adverse events in Japan, and that the Japanese version of the PRO-CTCAE had acceptable reliability and validity for common and clinically important symptoms.