Abstract
OBJECTIVES: To evaluate the impact of restrictive prophylactic antibiotic guidelines on the incidence of surgical site infections (SSIs) following elective spinal surgery using nationwide quality assessment data from South Korea. DESIGN: Nationwide retrospective cohort study comparing SSI rates between unrestricted (seventh and eighth quality assessment waves) and restricted (ninth wave) prophylactic antibiotic guideline periods using multivariable logistic regression. SETTING: All healthcare institutions performing elective spinal surgery and participating in the Health Insurance Review and Assessment Service (HIRA) quality assessment programme in South Korea. PARTICIPANTS: A total of 58 829 adult patients who underwent elective spinal surgery during the seventh (2015), eighth (2017) and ninth (2020) HIRA quality assessment waves were included. INTERVENTIONS: None. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the incidence of post-operative SSIs. Secondary outcomes included non-surgical site infections and factors associated with SSI occurrence. RESULTS: The overall post-operative infection rate was 5.79%. The incidence of SSIs was significantly higher in the restricted antibiotic group than in the unrestricted group (2.41% vs 0.84%). In multivariable logistic regression analysis, restrictive prophylactic antibiotic use was independently associated with an increased risk of SSIs (adjusted OR, 2.48; 95% CI 2.13 to 2.89; p<0.001). When stratified by hospital type, patients treated in tertiary hospitals had the highest SSI risk (adjusted OR, 4.47; 95% CI 3.65 to 5.47), followed by those treated in general hospitals (adjusted OR, 3.03; 95% CI 2.55 to 3.60) (all p<0.001). Non-surgical site infections were also more frequent in the restricted group. CONCLUSIONS: Restrictive prophylactic antibiotic guidelines were associated with a higher incidence of post-operative infections following elective spinal surgery. These findings suggest that prophylactic antibiotic strategies may need to consider patient risk profiles and surgical complexity rather than applying a uniform approach.