Abstract
BACKGROUND: Performance status is a useful prognostic index in palliative care. The objectives of this study were to investigate the prognosis of near-end-of-life patients with advanced lung cancer admitted due to deteriorated performance status, evaluate the utility of performance status measurement in predicting life expectancy, and identify prognostic factors using Bayesian proportional hazards models. METHODS: This prospective observational cohort study measured at admission, the Performance status, Palliative Performance Scale, Karnofsky Performance Status (KPS), Palliative Prognostic Index scores, and clinical biochemistry parameters of the included patients. Ninety-two patients with advanced lung cancer and deteriorated performance status admitted to our department at the NHO Yonago Medical Center between January 2016 and December 2018 were analyzed. Bayesian proportional hazards models were employed to classify remaining life prognoses. The Watanabe-Akaike information criteria (WAIC) with the lowest score was used to choose the final model. RESULTS: The median survival time was 25 (range, 1-107) days. The final prognostic model for the dying trajectory of patients was selected as an M-spline proportional hazards model according to the least WAIC. Independent prognostic factors for shorter remaining life were hypercalcinemia [hazard ratio (HR) 5.37, 95% confidence interval (CI) 2.11-12.9] and low KPS (HR 1.77, 95%CI 1.30-2.46). CONCLUSION: Assessing hypercalcinemia and KPS can be advantageous for predicting near-end-of-life prognosis in terminally ill patients with advanced lung cancer.