Effects of hospitalization before hemodialysis on mortality in dialysis patients

Background: In older adults, hospitalization often leads to increased frailty, which can result in higher rates of subsequent hospitalization and mortality. This study investigated whether a history of hospitalization before initiating dialysis affected mortality rates in dialysis patients. Methods: We analyzed 2,765 patients who visited hemodialysis clinics at 17 teaching hospitals. The study examined the association between mortality and various factors, including demographics, comorbidities, laboratory findings, and medication use. Hazard ratios (HR) were calculated using survival analysis to determine whether prior hospitalization increased mortality risk in dialysis patients. Results: Of the subjects, 8.0% (n = 222) had been hospitalized for 1 month or longer within the year before starting dialysis. There was no significant difference in gender between the two groups; however, the hospitalized group was older, and many patients in this group began dialysis using a catheter. This group also had a higher prevalence of conditions such as cerebrovascular accidents (CVA), hypertension, dementia, heart failure, and atrial fibrillation. Laboratory findings revealed higher platelet counts and blood urea nitrogen (BUN) levels, but lower levels of intact parathyroid hormone, creatinine, albumin, alkaline phosphatase, and cholesterol. Additionally, this group used fewer medications, including renin-angiotensin-aldosterone system blockers, calcium channel blockers, and antiplatelet agents. In multivariate analysis, controlling for factors such as age, sex, dialysis access, comorbidities (e.g., dementia, malignancy, ischemic heart disease, CVA, heart failure, atrial fibrillation, liver cirrhosis, fractures), ejection fraction, and laboratory markers (e.g., lymphocytes, platelets, BUN, creatinine, albumin, phosphorus, total cholesterol), the HR for mortality in the group with a history of hospitalization was 1.686 (95% CI, 1.162–2.447). Conclusions: Patients hospitalized for more than 1 month before starting dialysis had significantly higher overall mortality rates. These findings highlight the need for comprehensive care and targeted interventions for this high-risk population. Clinical trial number: Not applicable.