According to a recent study, 3.3% of Medicare beneficiaries ...

... had 4 or more emergency department visits (were frequent ED users) in 2009. Of these, in the following year:

• 34.3% were frequent emergency department users in 2010
• 19.4% did not visit an emergency department in 2010
• 39.0% were infrequent emergency department users in 2010
• 7.4% died in 2010

Source: "Risk Factors for Persistent Frequent Emergency Department Use in Medicare Beneficiaries," Annals of Emergency Medicine, March 3, 2016, http://www.annemergmed.com/article/S0196-0644(16)00084-6/abstract