Development and validation of the Quality of Dying Index for adults aged 80 and older at the end of life

With population aging accelerating, ensuring high-quality end-of-life care for older adults is urgent. This study developed and validated the Quality of Dying Index (QODI) for adults aged 80-105 using data from 2,705 decedents in the 2022 Chinese Longitudinal Healthy Longevity Survey. The 23-item QODI includes three subdomains: activities of daily living, cognitive functioning, and hospitalizations. Internal consistency was high (Cronbach's α ≥ 0.90), and convergent and divergent validity were supported by significant correlations with related constructs. Known-group validity was confirmed, and concurrent validity was demonstrated with AUC ≥ 0.70 across subdomains. Findings were consistent across age and sex subgroups. The QODI is a reliable, multidimensional tool for assessing the quality of dying in advanced old age, offering insights to inform hospice planning and end-of-life services. Developed and initially validated in a Chinese cohort, the index has uncertain external validity to other countries and cultural groups, and cross-national validation is warranted.