Developing an evidence-based intervention for surgical antibiotic prophylaxis use in women undergoing Caesarean delivery in Antigua and Barbuda

Thesis

Antibiotic misuse in hospitals drives antimicrobial resistance (AMR) and threatens global health. An effective response requires locally generated evidence to inform the design of context-specific, evidence-based interventions. However, limited research on antibiotics in the Caribbean Community States constrains the region’s efforts to address AMR.

The aim of this thesis was to develop an evidence-based intervention for standardising surgical antibiotic prophylaxis in women undergoing Caesarean deliveries (C-sections) in Antigua and Barbuda. A multi-phased approach comprising several study designs was guided by the Medical Research Council Framework for Complex Interventions. Three evidence syntheses defined the evidence base for antibiotic prescribing and use in CARICOM states, antimicrobial stewardship interventions targeting hospital workers across geographical locations, and global clinical practice recommendations for surgical antibiotic prophylaxis in C-sections. It was concluded that evidence on antibiotic use in CARICOM States is limited to two countries; AMS intervention components are poorly described and infrequently evaluated in low-income settings; and the quality of and recommendations for surgical antibiotic prophylaxis vary across countries. To understand antibiotic use in Antigua and Barbuda, a cross-sectional study on systemic antibiotic prescribing, a retrospective analysis of prophylactic antibiotic use in C-sections, and a COM-B informed qualitative study exploring factors influencing decision-making around surgical antibiotic prophylaxis in Csections were conducted. The cross-sectional study showed that 37% (n=10,377) of all systemic antibiotic prescriptions were cephalosporins, while 24% (n=6709) were metronidazole. However, no clinical information was available, limiting interpretation of the prescribing data. In the retrospective analysis, multivariable regression demonstrated significant temporal and consultant-based variation in the use of single-regimen preoperative surgical antibiotic prophylaxis and in the duration of postoperative prophylaxis (p<0.001). These findings were further supported by the qualitative investigation, which identified consultant preference as a key determinant of surgical antibiotic prophylaxis prescribing and insufficient physical resources and social opportunities as influences on prescribing behaviour.

Findings informed a Delphi study to establish formulary content consensus for surgical antibiotic prophylaxis. Expert consensus agreement was reached on 13 items to be included in a formulary. Using the Behaviour Change Wheel, cumulative findings from all investigations informed a context-specific intervention strategy to standardise surgical antibiotic prophylaxis during C-sections in Antigua and Barbuda.

Authors: Wade, TMAP

• DOI: 10.5287/ora-mjr8qorrn
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: Behaviour Change Wheel; implementation; Caribbean; Antigua and Barbuda; evidence-based healthcare; Medical Research Council; surgical antibiotic prophylaxis; antimicrobial stewardship; caesarean section
• Subjects: Evidence-based healthcare; Antimicrobial stewardship