Reliability, validity, and responsiveness of the Japanese version of the EORTC QLQ-ELD14 in evaluating the health-related quality of life of elderly patients with cancer

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 alpha 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.