Risk factors and impact of preoperative antibiotic prophylaxis on surgical site infection: A prospective study

Abstract

Background: Surgical site infections (SSI) are common postoperative complications, especially in resource-limited settings. Adherence to evidence-based preoperative antibiotic prophylaxis — correct agent, dose, and timing — is a cornerstone of SSI prevention. Methods: In this prospective observational study of 100 surgical patients at Department of Surgery, Patuakhali Medical College Hospital, Patuakhali, Bangladesh from 10th May 2025 to 10th August 2025, we recorded preoperative antibiotic practices, patient risk factors, and SSI incidence (CDC definitions) over 30 days postoperatively. Adherence was defined as administration of an appropriate antibiotic (per institutional protocol) within 30-60 minutes before incision at the correct dose. Associations with SSI were evaluated using univariate and multivariable logistic regression. Results: SSI occurred in 9% of patients, predominantly superficial (77.8%). On univariate analysis, higher BMI was significantly associated with SSI (OR 1.16; 95% CI 1.01-1.34), while drain use, contaminated wounds, prolonged operative duration, and blood loss >500 mL showed non-significant positive associations. In adjusted analysis, contaminated wounds and drain use remained positively associated, whereas optimal antibiotic timing showed a non-significant protective trend (aOR 0.38; 95% CI 0.08-1.75). SSI incidence was lower among adherent patients (6.9%) than non-adherent patients (11.9%) (RR for non-adherence = 1.73). Conclusion: The observed SSI incidence was within international benchmarks. Trends highlight the influence of wound classification, procedural factors, and timely antibiotic administration on SSI risk. Strengthening adherence to prophylaxis protocols and implementing bundled SSI prevention strategies could further reduce infection rates in similar settings.