Early hospital readmission among hemodialysis patients in the United States is associated with subsequent mortality.

Dialysis providers in the United States may soon be held accountable for their patients' 30-day hospital readmissions. However, few studies have evaluated the timing of readmissions, which determines the window in which dialysis providers could act to prevent readmission. We therefore examined the timing of readmissions of hemodialysis patients in the United States and its association with mortality among 285,795 prevalent adult Medicare-primary hemodialysis patients from a national registry. Patients had at least one hospitalization in 2010-2013 (first index) and survived for 30 days or more. Readmission timing was defined as 0-7, 8-14, or 15-30 days after the index discharge. Multivariable Cox proportional hazards models were used to estimate the association between readmission timing (referent no readmission) and mortality, censored at one year. Overall, 23.1% of patients had readmissions within 30 days of the index discharge, of which over one-third (35.9%) were within the first week. Regardless of timing, patients with readmissions had a higher risk of death within one year, compared to those with no readmissions, with hazard ratios of 2.04 (95% confidence interval 2.00-2.09) for being readmitted within 15-30 days; 1.98 (1.93-2.04) for being readmitted within 8-14 days; and 1.76 (1.71-1.80) for being readmitted within 0-7 days. Thus, opportunities for dialysis providers to intervene and prevent early readmission may be limited. Regardless of the timing, readmission appears independently associated with a substantially increased risk of mortality in this population.