Evaluating Legit.Health Plus Support for Improving Diagnosis of Generalized Pustular Psoriasis and Other Skin Conditions Among Primary Care Physicians and Dermatologists

This investigation is structured as a multi-reader multi-case (MRMC) study. A cohort of 15 healthcare professionals, including 11 primary care physicians and 4 dermatologists, acted as the "readers". These readers evaluated a "case" set of 100 clinical images to assess diagnostic performance both with and without the assistance of the AI device.

Study Design and Technical Methodology The research was conducted as a prospective observational and cross-sectional study. It utilized a "physician-as-their-own-control" design to measure the impact of Artificial Intelligence (AI) on diagnostic performance.

• Intervention Workflow: Participants accessed a dedicated web platform where they were presented with 100 clinical cases.
• Evaluation Steps: For each case, practitioners first evaluated a clinical image alongside anamnesis data (e.g., allergies, systemic symptoms) to provide an initial diagnosis.
• AI Support: Subsequently, they were presented with the AI's top 5 suggested diagnoses and associated confidence levels before making a final assessment.
• Image Sourcing: Cases consisted of high-quality images of Generalized Pustular Psoriasis (GPP), Hidradenitis Suppurativa (HS), and various differential "look-alike" conditions such as subcorneal pustular dermatosis and palmoplantar pustulosis.
• Data Sources: These images were curated from public dermatology atlases and internal research databases from the sponsor.

Quality Assurance and Data Management

To ensure the scientific integrity and reliability of the findings, several quality control measures were implemented:

• Data Validation: A validation process of the clinical data was carried out by running computer filters based on validation rules.
• Error Detection: These filters automatically identify missing values or inconsistencies. This was supplemented by manual editing and exploratory statistical techniques to detect logical errors and inconsistencies.
• Monitoring Plan: The investigation was overseen by a designated clinical monitor appointed by the sponsor.
• Remote Supervision: Monitoring activities included remote meetings every three months to review study progress and ensure ongoing compliance.
• Bias Minimization: Random selection of healthcare professionals (HCPs) was used to ensure that outcomes were not influenced by pre-existing participant characteristics.
• Standardization: The use of standardized procedures ensured that all participants were evaluated in the same way.

Statistical Analysis Plan

The primary goal of the analysis was to quantify Top-1 accuracy, sensitivity, and specificity for both general practitioners and dermatologists.

• Comparative Metrics: The analysis focused on the absolute metric values compared against the state of the art, as well as the percentage of variation attributable specifically to the use of the device.
• Subgroup Analysis: A dedicated analysis was performed for rare diseases, including GPP, Acne Conglobata, and Pemphigus Vulgaris, to assess the device's utility in high-complexity, low-incidence conditions.

Ethical and Confidentiality Framework The study adhered to UNE-EN ISO 14155:2021, the Declaration of Helsinki, and the General Data Protection Regulation (GDPR).

• Anonymization: No data enabling the personal identification of participants or patients was collected.
• Encryption: All information was managed securely in an encrypted format.
• End of Study: All information stored in the device will be totally and permanently deleted at the end of the study.