Beyond guideline deviation: understanding surgical antibiotic prophylaxis nonadherence in Iranian surgical practice using the theoretical domains framework

Surgical antibiotic prophylaxis (SAP) is essential for preventing surgical site infections, yet inappropriate perioperative antibiotic use remains a persistent stewardship challenge. Although SAP non-adherence is well documented, the behavioral and organizational mechanisms sustaining it remain poorly understood in Iranian surgical settings. This study assessed SAP adherence and explored factors shaping perioperative antibiotic prescribing and implementation. This explanatory mixed-methods study included a three-month retrospective assessment of SAP adherence followed by qualitative interviews. Adult patients undergoing elective colorectal and urologic surgeries in a tertiary university-affiliated hospital were included. SAP adherence was assessed using routinely collected hospital data based on indication, antibiotic selection, dose appropriateness, and duration. Antibiotic exposure was measured using length of therapy (LOT), days of therapy (DOT), and defined daily dose (DDD). Semi-structured interviews were then conducted with healthcare professionals to explore factors underlying the observed patterns of SAP non-adherence. Interview data were analyzed using directed content analysis guided by the Theoretical Domains Framework (TDF). Among 109 patients, only 10 (9.2%) met all SAP adherence criteria. Although indication was appropriate in all patients and dosing was appropriate in 105 patients (96.3%), non-adherence was mainly driven by inappropriate antibiotic selection and prolonged postoperative continuation. Antibiotics were continued beyond 24 h in 93 patients (85.3%), beyond 48 h in 82 (75.2%), and prescribed at discharge in 66 (60.6%). Antibiotic exposure was substantial, with median LOT, DOT, and total DDD of 4.0, 6.0, and 6.3, respectively. Fifteen interviews were conducted to explain these adherence patterns, identifying perceived infection risk, broad-spectrum prescribing norms, unclear responsibilities, workflow disruptions, professional responsibility concerns, patient expectations, and lack of structured antibiotic review as key drivers of persistent non-adherence. SAP non-adherence was common and extended beyond the decision to prescribe prophylaxis. Improving SAP practice requires stewardship interventions that address prescribing culture, perioperative workflow, and structured postoperative antibiotic discontinuation.