Amit Garg, Andrew Strunk, Bria Midgette, Kelly Frasier, Erica Cohn, Pim Aarts, Afsáneh Alavi, Raed Alhusayen, Bitte Falk G. Bechara, Vincenzo Bettoli, Alain Brassard, Debra Brown, Nisha Suyien Chandran, Siew Eng Choon, Steven R. Cohen, Steven Daveluy, V. del Mármol, Robert P. Dellavalle, Lennart Emtestam, Farida Benhadou, Pablo Fernández‐Peñas, Richard Flowers, John W. Frew, Kurt Gebauer, Evangelos J. Giamarellos‐Bourboulis, Noah Goldfarb, Barbara Horváth, Jennifer L. Hsiao, Gregor B. E. Jemec, Michelle A. Lowes, Angelo Valerio Marzano, Łukasz Matusiak, Robert G. Micheletti, Hazel H. Oon, Lauren A.V. Orenstein, Alex G. Ortega‐Loayza, So Yeon Paek, J.C. Pascual, Vincent Piguet, Barry I. Resnik, David Rosmarin, Gretchen M. Roth, Christopher J. Sayed, Dimitri Luz Felipe da Silva, Linnea Thorlacius, Thrasyvoulos Tzellos, Hessel H. van der Zee, Kelsey van Straalen, John R. Ingram
Importance: Accurate classification and reliability in assessment for lesions of hidradenitis suppurativa (HS) by investigators is critical to the determination of responder status and to overall data quality in clinical trials. Objective: To establish consensus-based morphological definitions of HS lesions and guidance statements that standardize investigator lesion assessments for implementation in clinical trials. Evidence Review: Health professionals (primarily dermatologists) with expertise in the measurement of HS disease activity as well as novice raters completed a preliminary questionnaire in which participants were asked to assess images of HS lesions and provide qualitative feedback on their decision making. Based on this feedback, detailed morphologic definitions for lesions and guidance statements that standardize lesion assessments were formulated and presented for consensus voting in 2 electronic Delphi surveys. A virtual group discussion after round 1 supported participants in round 2 voting. Findings: Response rates were 84.7% (50 of 59), 86.0% (43 of 50), and 90.9% (40 of 44) in the preliminary, electronic Delphi round 1, and electronic Delphi round 2 surveys, respectively. Morphological definitions for 11 lesion types achieved the prespecified 70% consensus threshold, with 9 definitions reaching at least 90% agreement. After 2 electronic Delphi rounds, 16 of 18 guidance statements achieved the prespecified consensus threshold, with 13 statements receiving endorsement from more than 80% of participants. Two guidance statements related to assessment of tunneled plaques with multiple openings and assessment of scalp lesions failed to reach consensus. Conclusions and Relevance: Common morphologic definitions and guidance that standardize assessment of HS lesions can be implemented in clinical trial protocols and investigator trainings with the goals of improving accuracy and reliability of investigator ratings.