Study design: the fairest possible test
We assembled 5,000 clinical photographs from consenting patients at 8 Indian dermatology clinics (Delhi, Mumbai, Bengaluru, Hyderabad, Chennai, Kolkata, Pune, Lucknow). Each photograph was independently evaluated by: (1) the AI system, (2) three randomly assigned dermatologists from a panel of 12. Neither AI nor dermatologists had access to patient history, only the photograph. Each evaluator assessed: primary skin conditions present (from a standardised list of 23 conditions), severity grade (mild/moderate/severe), affected facial zones (12 zones), and recommended first-line treatment approach. Agreement was measured as: exact match (identical condition identified), partial match (correct condition family, different subtype), and miss (condition not identified). A "ground truth" diagnosis was established by consensus of all 12 dermatologists reviewing full patient records.