P073 Where are we with developing diagnostic criteria for skin diseases? A 2024 update

Abstract A map of diagnostic criteria aims to provide clinicians with a repository of tools to assist diagnosis, guiding them to available criteria. We initially published a table exploring the scope of dermatological diagnostic criteria in 2021. The Centre of Evidence Based Dermatology resource, established in 2022, provides 163 different diagnostic criteria covering 95 skin diseases (https://www.nottingham.ac.uk/research/groups/cebd/resources/diagnostic-criteria-map.aspx). Our original report was intentioned to inaugurate surveillance of diagnostic criteria as a living map. An update with the newest published diagnostic criteria enables health professionals and therefore patients to benefit from the latest dermatological research in this field. We are also able to identify trends, and acknowledge activity or deficit of criteria, so that new research is initiated. A PubMed search was conducted in October 2024, using the same search strategy and exclusion criteria from our previous search in 2021, with the aim to review activity from then to the current time. Studies with a primary research aim to develop, validate or critically appraise diagnostic criteria for a skin disease were included. There were no restrictions on stage of diagnostic criteria development, study type or publication status. Papers underwent single-reviewer citation screening, full-text eligibility review and data extraction. Queries were discussed with a second reviewer. The skin diseases were sorted into groups based on similarities in pathology. The search identified 120 results: 54 full-text papers were reviewed, and of these 28 papers covering 24 skin diseases were included in data extraction. Studies were conducted most frequently in the USA. The largest disease category was ‘rare disorders and genetic syndromes’. The mean number of study participants was 492. The sample size range was 8–4664. Cross-sectional studies accounted for 57%, while 21% were case series and 11% were consensus studies. Most (96%) proposed predominantly clinical diagnostic criteria. Around one-half (57%) included validation studies, while 39% of studies provided diagnostic accuracy data such as sensitivity, specificity, positive predictive value or negative predictive value. Compared with the preceding 30 years, there has been over 100% increase in studies that are validating. Cross-sectional studies increased by 33%, which has contributed to a 5% increase in diagnostic accuracy data. Overall in this 2-year window, it appears we are moving towards more evidence-based diagnostic criteria proposals with studies focused on validating and testing the accuracy of criteria.