ABSTRACT
PURPOSE: This study evaluated the reliability, validity, and responsiveness of the Japanese version of the European Organization for Research and Treatment of Cancer (EORTC) QLQ-ELD14 and measured the health-related quality of life (HRQOL) of elderly Japanese patients with cancer aged ≥ 60 and ≥ 70 years. METHODS: The study recruited elderly Japanese patients with cancer aged ≥ 60 (≥ 70) years (n = 1803 [n = 1236]). The EORTC QLQ-ELD14 was evaluated for reliability, validity, responsiveness, and correlations of changes in score between the EORTC QLQ-ELD14 and the EORTC QLQ-C30 before and after the commencement of the COVID-19 pandemic. RESULTS: In both age groups, the proportion of missing items was low (< 3%). Cronbach's α was good at ≥ 0.70, except for two of the seven items. All the intraclass coefficient constants were good at ≥ 0.70. The concurrent validity was good but correlation with the EORTC QLQ-C30 was not strong, except for the hypothesis items. Regarding the assessment of responsiveness, only one item ("maintaining purpose") of the EORTC QLQ-ELD14 worsened (- 6.14 ± 29.20, standard response of mean > 0.2) after the commencement of the COVID-19 pandemic. The changes in score between the EORTC QLQ-ELD14 and the "global health status/QOL" and "summary score" of the EORTC QLQ-C30 had moderate-to-high negative correlations for all items, except two. Hypotheses to evaluate construct validity were accepted at 90%, while responsiveness was accepted at 80%. CONCLUSION: The Japanese version of the EORTC QLQ-ELD14 questionnaire appears to have acceptable reliability, validity, and responsiveness to evaluate HRQOL in elderly Japanese people with cancer.