Adherence to surgical antibiotic prophylaxis guidelines in New South Wales, Australia : identifying deficiencies and regression analysis of contributing factors

Background: Surgical antibiotic prophylaxis is frequently reported in the literature to be suboptimal, a finding having both clinical and public health implications. This study aimed to calculate rates and patterns of adherence to guidelines at two sites and identify extrinsic contributing factors. Methods: A retrospective analysis was conducted over two 12-mo periods during 2013–2014 at the metropolitan Blacktown Hospital and regional Lismore Base Hospital, New South Wales, Australia. A group of 400 patients undergoing abdominal general surgery was selected via simple random sampling (n = 200 per site). Medical records were reviewed, and prophylactic antibiotic regimens were compared with the Australian guideline, Therapeutic Guidelines: Antibiotic (v. 14) with respect to drug choice, dosage, timing of administration, and duration of administration. Results: The overall rate of adherence to the guidelines was 16.5% at Blacktown Hospital and 19.5% at Lismore Base Hospital. At each site, prophylaxis was administered to more than 95% of patients and was inappropriately withheld in 4%. Drug choice was the most frequent error type, specifically involving inappropriate omission of metronidazole and use of newer-generation cephalosporins. Errors in the timing of administration also were frequent, with prophylaxis typically occurring excessively early. Logistic regression identified emergency surgery as independently associated with prophylactic errors in both the Blacktown Hospital (p < 0.001) and the Lismore Base Hospital cohorts (p = 0.020). Conclusions: Adherence to antibiotic prophylactic guidelines was poor at both the metropolitan and regional sites. Choice of antibiotic and timing of administration were identified as major error types. Consideration should be given to multidisciplinary involvement of anesthetists, implementation of focused interventions with an emphasis on emergency settings, and further research correlating antibiotic use with clinical significance.