Delirium is independently associated with early mortality in elderly patients starting hemodialysis

Background Delirium is an independent predictor of death in patients undergoing dialysis for end-stage renal disease (ESRD). However, it is unknown whether delirium during hospitalization at the start of hemodialysis (HD) in elderly populations is associated with early mortality. Methods We conducted a retrospective cohort study to investigate the association between delirium and early mortality in the elderly after starting HD. The cohort consisted of patients >= 75 years who started dialysis for ESRD at the National Center for Global Health and Medicine from 2010 to 2017 and at Yokosuka Kyosai Hospital from 2007 to 2011. Delirium was defined as patients who showed new symptoms of transient confused thinking and reduced awareness of their environment and were prescribed antipsychotic medications. The primary outcome was death within 1 year. Data were analyzed using Cox proportional hazard models with adjustments for baseline characteristics. A multinomial logistic regression was used to identify the determinants of patients developing delirium. Results We enrolled 259 patients (males, 60%); 33 patients were diagnosed with delirium. The primary outcome was observed in 19 patients with delirium (58%) and 24 patients without delirium (11%) (p < 0.01). Delirium was independently associated with all-cause mortality within 1 year after starting HD (hazard ratio 7.82, 95% confidence interval 4.26-14.3; adjusted hazard ratio 7.16, 95% confidence interval 3.49-14.7). Delirium was positively correlated with "cognitive impairment" as well as "the use of steroids." Conclusion Delirium is independently associated with early mortality in the elderly after starting HD.