Appropriateness of surgical antibiotic prophylaxis in Spanish hospitals: a national multicentre cross-sectional study

While surgical antibiotic prophylaxis (SAP) is a cornerstone of preventing surgical site infections, adherence to clinical guidelines determines its effectiveness. In Spain, nationwide data on SAP appropriateness are scarce. This study evaluated prescribing practices across Spanish hospitals to assess alignment with national standards and identify factors associated with inappropriate antibiotic use.

We conducted a multicentre, cross-sectional, point-prevalence survey (PPS) in hospitals nationwide in Spain. Adult and paediatric patients undergoing elective or urgent surgery in 11 surgical areas were included. SAP appropriateness was assessed based on the SEIMC/AEC national consensus and local clinical guidelines, if available. The primary outcome was overall appropriateness, which was defined as adherence to the recommended indication, antimicrobial agent, dose, route of administration, infusion duration, timing of administration and total duration of SAP. Agreement between guidelines was assessed using Gwet's AC1 coefficient. A mixed-effects logistic regression model was used to identify factors associated with SAP inappropriateness, accounting for institutional clustering and ensuring robust variable selection.

Among 2198 patients from 91 hospitals, overall SAP appropriateness was 31·8% (n = 699) according to national consensus, increasing to 41·3% (n = 764) when compared with local protocols. According to the national consensus, the primary cause of inappropriateness was SAP duration. Agreement between national and local guidelines was moderate (Gwet's AC1 0·68), with notable discrepancies in cardiac and thoracic surgery. Independent risk factors identified by the mixed-effects logistic regression model included the number of antimicrobial agents prescribed (OR 25·44, 95% CI 17·05-37·27; p < 0·001), and the use of amoxicillin-clavulanic acid (OR 2·64, 1·77-3·90; p < 0·001), or antibiotics classified as "other" (OR 15·03, 4·95-45·60; p < 0·001).

SAP appropriateness in Spanish hospitals is suboptimal, with a significant gap between national evidence-based guidelines and clinical practice. These findings underscore opportunities for targeted antimicrobial stewardship interventions.

This study was funded by the Spanish Foundation of Hospital Pharmacy (FEFH).