SSI caused by MRSA pushes bill to $60,000

Duke study tracks staggering costs of infections

Surgical-site infections (SSI) significantly increase the chance of hospital readmission and can cost as much as $60,000 per patient, according to Duke University Medical Center researchers who conducted the largest study of its kind to date.

Deverick J. AndersonIn particular, SSIs caused by methicillin-resistant Staphylococcus aureus (MRSA) can set off a spiral of charges to patients and unreimbursed costs to hospitals, says Deverick J. Anderson, MD, MPH, an infectious diseases specialist at Duke University Medical Center and lead author of the study.

"A lot of the estimates on the costs associated with various surgical-site infections kind of 'take on all comers,"' he tells Hospital Infection Control & Prevention. "They were not specifically related to MRSA, but there are cost estimates that quote anywhere from $3,000 to $30,000 in general and vary by type of procedure. I think what this [study] adds is there is also a [cost] variation based on the bug that causes SSIs as well."

While the $60,000 figure could include patient charges — as opposed to strictly hospital costs — even focusing solely on the latter yields a cost estimate in the $45,000 range per SSI caused by MRSA, Anderson says.

"These [MRSA] patients also required more than three weeks of additional hospitalization," he says. "We found that patients with surgical-site infections due to MRSA were 35 times more likely to be readmitted and seven times more likely to die within 90 days compared to uninfected surgical patients."

The Duke study provides the first cost impact data tied to post-surgical MRSA infection in a large group of hospitals. The estimates provide some perspective to the costs associated with SSI prevention, including efforts such as cleansing the surgical skin site and patient nasal decolonization. The Duke study evaluated deep-incision and organ/space infections, so the cost figures primarily pertain to SSIs beyond superficial infections at the site of incision.

"But now we are able to say from the hospital administration side, how much investment can we make in these sorts of strategies and what kind of exact payoff are we going to need in order to say that this was cost-effective for our institution?" Anderson says. "Say a hospital puts in an intervention that prevents one [MRSA-SSI] infection each year. If that intervention costs less than $45,000 to $60,000, then I think you could say it's a good intervention. Even though it only decreased one infection it still would have been cost-effective."

A $19 million price tag

Anderson's team looked at the 90-day postoperative period for patients over a five-year period in one tertiary care center and six community hospitals in the Duke Infection Control Outreach Network.1 They compared hospital readmission, mortality, length of hospital stay, and hospital charges for patients in three groups. Some had surgical-site infections due to MRSA, some were infected with methicillin-susceptible Staphylococcus aureus (MSSA), and some were uninfected.

In total, 150 patients with SSI due to MRSA were compared to 231 uninfected controls and 128 patients with SSI due to MSSA. An SSI due to MRSA was independently predictive of readmission within 90 days; death within 90 days; and led to 23 days of additional hospitalization and $61,681 of additional charges compared with uninfected controls.

"For the seven hospitals we looked at, the total estimated cost resulting from surgical-site infections due to MRSA was more than $19 million," Anderson says. "That's a staggering amount, which demonstrates an area of cost-saving potential for these institutions and other community hospitals."

The researchers found most of the outcomes for MRSA compared to MSSA were worse, as anticipated; however, one finding was surprising, according to Anderson. "Our findings show that methicillin-resistance contributed to longer hospital stays and increased hospital charges but did not increase the risk of mortality," he says.

The data show that patients with surgical-site infections due to MRSA compared to MSSA on average required six more days of hospitalization and incurred $24,000 in additional charges. However, the study adds to the conflicting data on whether MRSA entails higher mortality to surgical patients than MSSA, he says, adding there have now been four studies and the score is "2-2." The bottom line for costs, mortality, and any other measure is it's better not having acquired an SSI.

"Without doubt, when you look at MRSA infections vs. uninfected patients across the board everything is worse — mortality, costs, readmissions," Anderson says.

Reference

  1. Anderson DJ, Kaye KS, Chen LF, et al. Clinical and financial outcomes due to methicillin-resistant Staphylococcus aureus surgical-site infection: A multi-center matched outcomes study. PLoS ONE 2009; 4(12): Available at: http://www.plosone.org.