Study Examines Costs Associated with Surgical Site Infections
Surgical site infections (SSIs) are associated with excess morbidity and mortality. SSIs can be superficial infections, involving the skin or subcutaneous tissue only, or they can be more serious infections involving tissue under the skin, organs, or implanted devices or material, which are classified as deep infections. Recently, the costs of SSIs have been under scrutiny since the Centers for Medicare and Medicaid Services have stopped paying for the increased costs associated with some SSIs, citing that they are potentially preventable. This retrospective cohort study sought to determine the excess costs associated with both superficial and deep SSIs among all VA operations performed in FY10, including five high-volume surgical specialties – neurosurgery, orthopedic, general surgery, peripheral vascular, and urology. The main outcome measure was defined as total costs associated with the index hospital admission and readmissions within 30 days of discharge. Using VA data, investigators also estimated potential savings by reducing SSIs in hospitals with the highest risk-adjusted SSI rates to the median hospital rate. Other variables measured in this study included patient demographics, comorbid conditions, and wound classification (i.e., clean, contaminated, dirty/infected).
- Surgical site infections were associated with a significant increase in attributable post-surgical costs, even after adjusting for patient-level, surgical-level, and facility-level factors. Patients with deep SSIs had costs 1.93 times higher than patients without site infections. Moreover, if VA hospitals in the highest 10th percentile (e.g., worst) reduced their SSI rates to the rates found in the 50th percentile, the VA healthcare system could save about $6.7 million per year.
- The greatest mean cost attributable to SSI was among neurosurgery patients ($23,755), followed by orthopedic surgery, general surgery, peripheral vascular surgery, and urology.
- Among 54,233 Veterans who underwent surgery in FY10, 1,756 (3%) experienced an SSI. Overall, 0.8% of the cohort had a deep SSI and 2.4% had a superficial SSI. Veterans who experienced an SSI were more likely to have pre-operative comorbid conditions (e.g., diabetes, chronic obstructive pulmonary disease) and were more likely to drink more than two drinks per day in the two weeks before the operation. They also were more likely to have a more severe wound classification – and to undergo emergent surgery.
- Study data only included Veterans followed for 30 days post-operatively, even though CDC guidelines suggest patients who receive a surgical implant should be followed for a year. Thus, results may underestimate the costs associated with SSIs, particularly for orthopedic operations.
- Costs and burden of superficial SSIs are usually incurred in the outpatient setting and would not be captured in this cost analysis. Therefore, the costs of all SSIs may be underestimated.
NOTE: Investigators are currently implementing a bundle of interventions to reduce SSI in 10 VA facilities.
Dr. Schweizer was supported by an HSR&D Career Development Award. Drs. Schweizer, Perencevich, and Vaughan Sarrazin are part of HSR&D's Center for Comprehensive Access & Delivery Research and Evaluation (CADRE) in Iowa City, IA.
Schweizer M, Cullen J, Perencevich E, and Vaughan Sarrazin M. Costs Associated with Surgical Site Infections in VA Hospitals. JAMA Surgery May 21, 2014;e-pub ahead of print.