DS02 The first 3 years of national data from the British Society for Dermatological Surgery Mohs micrographic surgery logbook
Authors: Bray Adam 
Published: June 2024

Abstract
A secure online electronic logbook for UK Mohs surgeons was launched in February 2021. We present the first 3 years of data. The purpose is to facilitate all units to record the British Society for Dermatological Surgery (BSDS) Mohs surgery minimum dataset, to use for training, professional development, quality assurance, and improving outcomes for patients. Anonymized data were aggregated using the logbook reporting functions, and raw data in Excel. In total, 8693 cases were logged from 2021 to 2024, with a mean of 580 per active unit (range 1–1526); 23 units are registered, with 15 logging regularly. Seventy-six surgeons logged cases, with an average of 113 cases per surgeon (median 63; range 1–795). The mean patient age was 69 years (range 15–99; 2.3% ≥ 90 years old), and the male-to-female ratio was 0.99. The mean number of resection stages (Mohs layers) was 1.5 (range 1–8). The mean maximum tumour/defect diameters were 14 mm preoperatively and 20 mm postoperatively. Overall, 80% were reconstructed on the same day; 32% were by linear or partial closure, 30% local flap, 16% graft, and 9% secondary intention. In total, 90% were reconstructed by dermatology. Overall, 43% of cases had a preoperative histology diagnosis entered: 2734 basal cell carcinoma (93%), 133 squamous cell carcinoma (5%), 12 sebaceous carcinoma, 10 dermatofibrosarcoma protuberans, 9 microcystic adnexal carcinoma, 3 unspecified follicular tumours, 1 atypical fibroxanthoma, 1 Merkel cell carcinoma, and 36 others not specified. Most (99.6%) were on the head or neck, with 39% on the nose or paranasal. Each unit completed on average 81% of the mandatory logbook items (range 0–100%). The commonest missing data were related to postoperative outcomes collected after 3 months, for example the final histology diagnosis (28% completed), complications (6%), aesthetic outcomes reported by patient and doctor (5–6%), and functional outcome (5%). Of those with postoperative complications completed, 84% had no complications, while 8.1% reported dehiscence or necrosis, 5.0% wound infection, and 2.9% bleeding or haematoma. Therefore, approximately 1 in 6 patients with data experienced one of these complications. Functional deficit was captured separately, with 84% of those reported as having no functional deficit, 7.5% numbness, 3.8% ectropion or epiphora, 2.4% nasal breathing difficulty, 2.2% pain or discomfort, and 0.8% localized paresis. Overall, 95% of those with complications required no additional treatment, with 3.2% needing a scar revision, 0.64% an unplanned readmission to hospital, and 0.32% an unplanned return to theatre. Of those with aesthetic outcome data, 68% of patients answered ‘not at all’ to the question ‘How much does your scar appearance bother you?’, while 26% reported ‘a little’, 5.2% ‘a lot’ and 0.3% ‘worst possible’. Use of the logbook is now standard practice for many UK Mohs surgeons, and most major training centres. Challenges remain for engaging others, and in gathering postoperative outcomes.