"Use of Hospital-Based Acute Care Among Patients Recently Discharged From the Hospital"
JAMA Jan 23/30 2013
http://jama.jamanetwork.com/article.aspx?articleid=1558277#qundefined
"Conclusions and Relevance 
After discharge from acute care hospitals in 3 states, ED visits within 30 days were common among adults and accounted for 39.8% of postdischarge hospital-based acute care visits. Improving care transitions should focus not only on decreasing readmissions but also on ED visits."