Seventy-two-hour returns may not be a good indicator of safety in the emergency department: a national study.

OBJECTIVES: The objective was to measure the association between returns to an emergency department (ED) within 72 hours and resource utilization, severity of illness, mortality, and admission rate.
METHODS: This was a retrospective, cross-sectional analysis of ED visits using data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 1998 to 2006. Cohorts were patients who had been seen in the ED within the past 72 hours versus those without the prior visit. A multivariate model was created to predict adjusted-resource utilization and mortality or admission rate.
RESULTS: During the study period, there were 218,179 ED patient visits and a 3.2% 72-hour return rate. Patients with Medicare (3.5%) and without insurance (3.5%) were more likely to return within 72 hours. Visits associated with alcohol (4.1%), low triage acuity (4.0%), or dermatologic conditions (5.9%) were more likely to return. Seventy-two-hour return visits used fewer resources (5.0 [±0.1] vs. 5.5 [±0.1] tests, medications, procedures), were less likely to be Level I triage acuity (17% vs. 20%), and had a similar admission rate (13% vs. 13%) as those not seen within 72 hours. The sample size was too small to evaluate mortality.
CONCLUSIONS: Patients who return to the ED within 72 hours do not use more resources, are not more severely ill, and do not have a higher hospital admission rate than those who had not been previously seen. These findings do not support the use of 72-hour returns as a quality or safety indicator. A more refined variation such as 72-hour returns resulting in admission may have more value.