Work

Interpreting EORTC CAT Core short-form scores in metastatic breast cancer: EQ-VAS-associated cut-points and comparison with published thresholds for clinical importance

Year: 2026

Type: article

Abstract: Background Published thresholds for clinical importance (TCIs) for the European Organisation for Research and Treatment of Cancer CAT Core were derived using domain-specific relevance anchors, which are not routinely collected. We estimated EQ-VAS-associated cut-points for EORTC CAT Core short-form scores in patients with metastatic breast cancer, compared them with published TCIs, and examined patient-reported Eastern Cooperative Oncology Group (ECOG) performance status as a secondary reference classification. Methods This post hoc cross-sectional analysis used data from the PRO B trial. EQ-VAS ≤ 70 was used to define lower global health status, with EQ-VAS ≤ 65 examined in sensitivity analysis; patient-reported ECOG ≥ 2 defined impaired performance status in secondary analysis. Receiver operating characteristic (ROC) analyses based on continuous CAT Core T-scores identified Youden-optimal cut-points with 5,000 bootstrap replications for estimating confidence intervals and optimism-corrected performance. Results Among 855 patients with CAT Core data available for the baseline analysis (mean age 51 years, SD 11), 841 had EQ-VAS and 854 had ECOG data. Using EQ-VAS ≤ 70, AUCs ranged from 0.57 to 0.82; eight of 14 domains had AUC ≥ 0.70, five had AUC 0.60–0.69, and diarrhea had AUC 0.57. Four domains did not meet the criterion used for interpretation of |ρ| ≥0.30 and were therefore interpreted as exploratory. Published TCIs showed different sensitivity-specificity profiles when evaluating against the EQ-VAS reference classification, illustrating the dependence of cut-point performance on the reference construct. Conclusions This study identified EQ-VAS-associated cut-points for EORTC CAT Core short-form scores in metastatic breast cancer. Their performance varied by domain, and they should be interpreted as context-specific reference values rather than replacements for published relevance-based TCIs.

Source: Journal of Patient-Reported Outcomes

DOI: 10.1186/s41687-026-01254-3