Some Seniors Readmitted with the Same Infections They Took Home

As many as 5% of patients leaving the hospital with an infection have a 30-day readmission for that preexisting infection.

A disproportionately high number of seniors return to the hospital within 30 days of discharge for pre-existing infections that were presumably treated during the first hospital stay, according to a study from Michigan Medicine.

"We found that as many as 5% of patients leaving the hospital with an infection have a readmission for that preexisting infection—that's bad," said study lead author Geoffrey Hoffman, assistant professor in the U-M School of Nursing. 

Hoffman and his colleagues looked Medicare records for more than 318,000 hospital discharges for patients 65 and older and found that 2.5% of them return because of linked infections.  

The study appears online in the Journal of The American Geriatrics Society.

The most common infection was Clostridioides difficile (roughly 5% readmission), followed by urinary tract infections (2.4% readmission). 

The 2.5% readmission rate looks small, Hoffman said, but he stressed that hospitals know how to treat these infections, and know patient has the infection upon discharge.  

"Presumably they've been treated for the infection since the hospital has already billed Medicare," Hoffman said. "Readmissions shouldn't be zero, but they should be much closer to zero." 

The number of patients with the same diagnosis at readmission and discharge is very narrow, Hoffman said, so the number will by default be much smaller than overall hospital readmissions.  

For instance, he said, heart failure and chronic obstructive pulmonary disease, or COPD, have about 10% and 8% linked readmission rates, respectively. Unlike infections, however, those complex conditions aren't entirely curable, so complications are more frequent. 

Surprisingly, patients discharged home or to home care were 38% more likely to return with a linked infection than those discharged to skilled nursing facilities, Hoffman said. 

"I was very surprised," he said. "This is somewhat conflated with the conventional wisdom, which is that skilled nursing facilities are warehouses for infection transmission."

"The fact that patients discharged to skilled nursing had lower readmission rates for Clostridioides difficile infections than people discharged home is pretty amazing, given that those patients by definition are sicker and would more likely to be readmitted than those discharged home," he said.  

Hoffman said the findings show that infections spread at higher rates in SNFs, but they're also good at treating them.

"There are probably some gaps in self-care for patients going home with an infection from the hospital," he said. "This suggests home health care agencies aren't up to snuff with infection control and patients going home without home health care probably need better training, as do their caregivers." 

The research was funded by the Agency for Healthcare Research and Quality, U-M Older Americans Independence Center Research Education Core and the U-M Pepper Center pilot.