Predictors of Need for First and Recurrent Emergency Medical Service Transport to Emergency Department after Dialysis Initiation

Background: Dialysis patients are frequently transported to the emergency department (ED) by Emergency Medical Services (EMS) due to acute and severe illness. However, little is known about predictors of first and recurrent transport to the ED (EMS-ED), based on characteristics at the time of dialysis initiation. Methods: We analyzed a cohort of adult (≥18 years) patients affiliated with a large quaternary care center who initiated chronic dialysis from 2009 to 2013 (last follow-up: 2015). Data on patient characteristics at the time of dialysis initiation were linked to regional EMS data. Candidate predictors of first and recurrent EMS-ED transport included comorbid conditions, dialysis characteristics and frailty severity (using the first version of the clinical frailty scale score; CFS). Time to first EMS-ED was analyzed using a multivariable sub-hazards regression model accounting for competing events (transplantation or death). Time to recurrent EMS-ED was analyzed using the Anderson-Gill counting approach, accounting for competing risks. Results: A total of 455 patients were included in the study, 243 (53%) had 1+ EMS-ED events, 90 (20%) never required an EMS-ED at last follow-up, and 69 (15%) and 53 (12%) experienced transplant or death as their first event, respectively. The mean age of the cohort was 62 ± 15 years, 89% were Caucasian, and 35% were female sex. Patients were highly comorbid and 97/381 (25.5%) with available data on frailty severity had a CFS score of ≥5, inclusive of CFS scores ranging from mildly to severely frail. After adjustment, a CFS score of ≥5 (relative to 1–2) was associated with a > 2-fold increase in the risk of first EMS-ED (subdistribution relative hazard; SHR 2.28, 95% confidence interval; CI 1.30–3.98). A history of peripheral vascular disease (SHR 1.43, 95% CI 1.00–2.03) and rheumatologic disease (SHR 1.84, 95% CI 1.00–3.38) was also associated with first EMS-ED. Frailty severity was the only factor associated with recurrent EMS-ED. Conclusion: Patients are at a high risk of EMS-ED after dialysis initiation. Frailty severity (at the time of dialysis initiation) is a strong predictor of first and recurrent EMS-ED and this may be important to guide informed decision making and resource planning for dialysis patients who require EMS.