Patterns of emergency department utilization by patients on chronic dialysis: A population-based study.

IMPORTANCE: Patients on dialysis are often elderly and frail, with multiple comorbid conditions, and are heavy users of Emergency Department (ED) services. However, objective data on the frequency and pattern of ED utilization by dialysis patients are sparse. Such data could identify periods of highest risk for ED visits and inform health systems interventions to mitigate these risks and improve outcomes.

OBJECTIVE: To describe the pattern and frequency of presentation to ER by dialysis patients.

DESIGN: Retrospective cohort study using administrative data collected over ten years (2000-2009) in the Province of Manitoba, Canada.

SETTING: Patients presenting to any of 9 ED's in Winnipeg and Brandon Manitoba. These departments serve >90% of the population of Manitoba, Canada (population 1.2 million).

PARTICIPANTS: All patients presenting to an ED in any of 9 emergency departments in Manitoba, Canada.

EXPOSURE: Dialysis status.

MAIN OUTCOMES: Presentation to the ED.

RESULTS: Over 2.1 million ED visits by more than 1.2 million non-dialysis patients and 17,782 ED visits by 3257 dialysis patients were included. Dialysis patients presented 8.5 times more frequently to the ED than the general population (age and sex adjusted, p<0.001). For dialysis patients, ED utilization was significantly higher following the long interdialytic interval (33.6% higher Mondays and 19.5% higher Tuesdays vs. other days of the week, p<0.001) and was 10-fold higher in the 7 days before and after the initiation of dialysis.

CONCLUSION AND RELEVANCE: The heavy use of ED services by dialysis patients spikes upward following the long interdialytic interval and also in the week before and after dialysis initiation. The relative risks associated with these vulnerable periods were much higher than those reported for clinical patient characteristics. We propose that intrinsic gaps in the structure of care delivery (e.g. 3 times a week dialysis, imperfect surveillance and clinical monitoring of patients with low GFR) may be the fundamental drivers of this periodicity. Strategies to mitigate this excess health risk are needed.