Twenty percent of Medicare inpatients rehospitalized within 30 days

Unplanned rehospitalizations of Medicare beneficiaries within 30 days leaving the hospital cost the program $17.4 billion in 2004, according to a study published April 2 on the web site of the New England Journal of Medicine. This equals about 17 percent of all hospital payments from Medicare in 2004. Almost one-fifth (19.6 percent) of beneficiaries discharged from a hospital that year were rehospitalized within 30 days. Only about 10 percent of these rehospitalizations were planned.

The NEJM study noted that "there is extensive literature on rehospitalization attributed to particular conditions, especially heart failure, there is very limited research addressing the broader issues involving the multitude of diseases and processes that contribute to rehospitalization."

Most rehospitalizations are related to medical diagnoses. The 100 most frequent rehospitalization DRGs accounted for 73.2 percent of all rehospitalizations. The study concludes that "[r]ehospitalization is a frequent, costly, and sometimes life-threatening event that is associated with gaps in follow-up care."