DS27 Establishing clinician and patient perspectives on a proposed trial investigating antibiotics in skin surgery

Abstract Surgical site infection (SSI) following excision of ulcerated skin cancers is a well-recognized complication; however, the exact risk is unknown and there is no consensus on antibiotic prescribing in this setting. The EXCISE trial (EXamining antibiotics for ulCerated skIn cancer Surgical Excision) aims to address this evidence gap. An online survey was distributed to the UK Dermatology Clinical Trials Network (UKDCTN), British Society for Dermatological Surgery and plastic surgery, ear, nose and throat (ENT) and maxillofacial surgery networks (December 2022). The survey aimed to establish clinicians’ views about the proposed EXCISE trial. A focus group with patient representatives with lived experience of skin cancer surgery was also conducted (n = 5). Ninety questionnaire responses were received: six plastic surgeons (7%), 19 oral and maxillofacial surgeons (21%), four ENT surgeons (4%) and 61 dermatologists (68%). Sixty-five per cent of responders were consultants, and 34% were registrars. Seventy-one (79%) were willing to recruit to the EXCISE trial. Forty-eight (53%) agreed to randomize patients to 0 (no antibiotics), 1, 2, 3, 5 or 7 days of postoperative flucloxacillin. Thirty-seven (41%) agreed a 6–10% absolute increase in risk of SSI would justify a shorter course of antibiotics (1–3 days) with fewer side-effects. Thirty-three (37%) felt a 0–5% absolute risk increase would be acceptable, 17 (19%) felt an absolute risk increase of 11% or greater was acceptable, and three (3%) did not respond. Eighty-one (90%) agreed that if the EXCISE trial demonstrated a reduction in SSI, they would prescribe antibiotics, 61 (68%) would prescribe longer courses (5–7 days) and 17 (19%) would prescribe shorter courses (1–3 days). Patients reported a preference for shorter antibiotic courses (1–3 days) vs. longer (5–7 days) if there were fewer side-effects and no increased risk of infection. All patients agreed, in principle, to randomization to the proposed groups and highlighted the need to recruit from diverse socioeconomic backgrounds. They also suggested highlighting zero days of postoperative antibiotics often reflects usual practice to encourage participation. All participants agreed with the proposed 10% noninferiority margin. In summary, our data demonstrate acceptability of the proposed EXCISE trial among both clinicians and patients. An absolute noninferiority margin of 10% between SSIs occurring in the context of longer courses of antibiotics vs. shorter courses of antibiotics is acceptable to patients when associated with fewer side-effects. Clinicians showed mixed responses, suggesting that further work is required to explore the barriers and facilitators to prescribing and for future implementation. Acknowledgments: The study was developed with support from the UK Dermatology Clinical Trials Network (UK DCTN). The UKDCTN is grateful to the British Association of Dermatologists and the University of Nottingham for financial support of the network.