Title : The double whammy of cardiac SSI under-reporting: Correcting incidence and inflation to unlock capacity and eradicate AMR debt
Abstract:
Surgical Site Infection (SSI) surveillance in cardiac surgery is distorted by a double whammy: systematic under-reporting of true infection rates and reliance on outdated, non inflation adjusted cost data. Enhanced recovery protocols have shortened inpatient stays, but national registries still track mainly in-hospital infections. This creates an in patient illusion where official SSI incidence appears to be only 1–2%, while WHO aligned surveillance capturing post discharge infections consistently finds rates nearer 5–6%. This gap falsely positions SSI prevention as a marginal priority undermining investment.
To quantify the impact of this distortion, a health economic model was developed for 1,000 UK cardiac surgeries. Two scenarios were evaluated: a Registry Scenario using the reported 1.5% incidence and historical costs (£10,000 per SSI), and a Corrected Reality Scenario applying a 5.0% incidence, inflation adjusted costs (£17,150 per SSI), and an additional 12 day excess length of stay per infection. The model incorporated lost Opportunity Revenue from the crowding out effect, whereby SSI related bed occupancy displaces new elective admissions.
Registry based assumptions identify only 15 SSIs, implying modest clinical and financial risk. Corrected modelling reveals 50 SSIs, consuming 600 excess bed days and £857,500 in direct costs, effectively an “infection tax” of £857.50 per surgery. Each infection also represents a biological debt of avoidable antibiotic exposure, directly undermining antimicrobial stewardship (AMS) goals. A resistance proof, non antibiotic prevention strategy achieving a 50% SSI reduction would prevent 25 infections, save £428,750 in direct costs, free capacity for 50 additional elective cases, and generate £750,000 in opportunity revenue (at £15,000 revenue per new surgery). The combined net economic value exceeds £1.17 million per 1,000, alongside reduced antibiotic use and AMR risk. This is a gain of £1,179 per surgical patient, or 7.9% of the average cost per surgery.
These findings demonstrate that current reporting practices suppress the apparent value of prevention and entrench a false economy that delays investment in innovative AMS solutions. Accurate post discharge SSI surveillance and inflation adjusted costing are prerequisites for robust business cases that align clinical governance, capacity planning, and AMS. In cardiac surgery and other high risk specialties, correcting the SSI double whammy can unlock capacity, eliminate hidden AMR debt, and reposition non antibiotic, resistance proof interventions as strategic assets for both patient safety and hospital performance.
