Reliability and Validity of the Korean Version of the Lymphedema Quality of Life Questionnaire in Breast Cancer-Related Lymphedema Patients.

Background: This study aimed to demonstrate the reliability and validity of the Korean version of the Lymphedema Quality of Life (LYMQOL) questionnaire. Methods and Results: This study was a multicentered cross-sectional survey of patients with breast cancer-related lymphedema. The LYMQOL-arm questionnaire was translated from English to Korean. This 28-item instrument contains the overall quality of life (QOL) and is categorized into four domains: function, appearance, symptoms, and mood. In addition, the demographics and characteristics of lymphedema were assessed by reviewing the medical records. The LYMQOL-arm, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30), and Breast Cancer Module 23 (EORTC QLQ-BR23) were administered. The internal consistency of the LYMQOL-arm was analyzed using Cronbach's α , and test-retest reliability was examined using the intraclass correlation coefficient (ICC). Concurrent validity was evaluated using Pearson's correlation test between the LYMQOL-arm and the EORTC QLQ instruments. A total of 62 participants were enrolled in the study. All domains of the LYMQOL-arm showed high internal consistency, and the ICC of each domain and overall QOL ranged from 0.836 to 0.956 ( p  < 0.001). All domains and overall QOL scores of the LYMQOL-arm significantly correlated with most of the EORTC QLQ-C30 and EORTC QLQ-BR23 scales. Furthermore, it revealed a significant association with the degree of perceived edema. Conclusions: The Korean version of the LYMQOL-arm questionnaire has proven its reliability and validity in assessing QOL in patients with breast cancer-related lymphedema.