Determinants of long-term quality of life in nasopharyngeal carcinoma survivors: the roles of household income and performance status.

Survivors of nasopharyngeal carcinoma (NPC) frequently suffer from a prolonged reduction in quality of life (QoL) following successful treatment. This study investigates the determinants of QoL among NPC survivors, with a focus on the temporal evolution post-treatment and the influence of socioeconomic and clinical factors. In this cross-sectional study, NPC patients who received treatment in the last 10 years and underwent follow-up at our institute from 2021 to 2023 were enrolled. They completed the EuroQol five-dimension (EQ-5D), World Health Organization Quality of Life-Brief (WHOQOL-BREF), Sinonasal Outcome Test 22 (SNOT-22), Eustachian Tube Dysfunction Questionnaire-7 (ETDQ-7), and Eating Assessment Tool-10 (EAT-10). Kernel smoothing techniques were applied to delineate the trends in QoL scores, and linear mixed models were utilized for evaluating the unadjusted and adjusted influences of household income and other predictors on QoL. Out of 248 participants, 355 QoL evaluations were performed. Kernel-smoothed trajectories revealed that higher household income correlated with superior QoL scores throughout the majority of the post-treatment timeline. Although initial analyses showed that both higher household income and Karnofsky Performance Scale (KPS) scores were predictive of better generic and condition-specific QoL, the effect of income was attenuated upon adjusting for KPS in the multivariate analysis. Mediation analysis indicated that the association between income and QoL was partly mediated by the patients' performance status. Performance status is a pivotal mediator in the interplay between socioeconomic status and QoL outcomes in NPC survivors. These insights underscore the need for prospective studies to confirm these relationships.