A breakeven analysis showed use of local vancomycin powder was cost-effective as prophylaxis against shoulder arthroplasty infection, according to study results presented at the American Shoulder and Elbow Surgeons Annual Meeting.
“[This study] shows that the use of vancomycin powder placed intraoperatively at the end of a shoulder arthroplasty is a highly cost effective intervention to diminish the risk of infection,” Laurence D. Higgins, MD, MBA, chief of Sports Medicine and Shoulder Service at Brigham and Women’s Hospital in Boston, told Orthopedics Today.
Cost for prophylactic use
To determine how effective vancomycin powder would need to be at reducing the baseline infection rate to make it cost-effective, Higgins and his colleagues developed a breakeven equation using an average cost of treating an infection across the stages of care in shoulder arthroplasty of $47,260, a cost of vancomycin powder of $17.15 per 1,000 mg vial and a literature-based baseline infection rate of 4%.
“What we showed through this kind of breakeven analysis was it only had to decrease the risk of infection by 0.04% using the current cost of vancomycin in our hospital system,” Higgins said.
Assuming a cost to treat infection of $47,260 and a vancomycin cost of $2.50 per 1,000 mg, the decrease in infection rate would need to be 0.0053% for the use of vancomycin powder to be cost-effective. Researchers noted a decrease in infection rate of 0.09% for the use of vancomycin powder to be cost-effective with a cost of vancomycin powder of $44 per 1,000 mg and a cost to treat infection of $47,260.
“We had all of these models, and what we showed was, within the bounds of reality, this intervention is highly cost-effective and is an appropriate intervention to make on behalf of the patient,” Higgins said.
Since orthopedic surgeons would want a prospective study showing the use of vancomycin powder as a worthwhile intervention, Higgins and colleagues performed a power analysis and found they would need to enroll 209 million patients to demonstrate the study was effective, reproducible and valid.
“The adult population of the United States would have to all get a shoulder replacement and be randomized into whether they had vancomycin or not, even if they did not need a shoulder replacement,” Higgins said.
He added, even if the price of vancomycin was at the highest expense and the infection rate was dropped as low as possible, the study would need 668,000 patients enrolled.
“Despite the fact that physicians traditionally require hard core data to inform their medical practice, there are situations, like the use of vancomycin powder, where that type of data is not applicable or even possible to obtain, where we would do a power analysis and determine how many patients we need to enroll in order to show that something is effective at treating a problem — infection in this case — and show that the treatment is cost-effective,” Higgins said. “In the spirit of practicality and given the economic reality of what we do, this is an elegant way to determine and show that interventions like vancomycin powder are highly cost-effective, even though we do not have rigorous level 1 or level 2 data to support its use.” – by Casey Tingle
- Hatch MD, et al. Paper #5. Presented at: American Shoulder and Elbow Surgeons Annual Meeting; Oct. 7-9, 2016; Boston.
- For more information:
- Laurence D. Higgins, MD, MBA, can be reached at Brigham & Women’s Hospital, 75 Francis St., Boston, MA 02115; email: firstname.lastname@example.org.
Disclosure: Higgins reports no relevant financial disclosures.