Real-life evaluation of the effectiveness of biologics for chronic rhinosinusitis with nasal polyps in Europe: A Delphi study to define key variables for the INVENT registry

Vibeke Backer^1*Eugenio De Corso²Geoffrey Mortuaire³Emmanuel Prokopakis⁴Anette Drøhse Kjeldsen^5,6Philippe Gevaert⁷Adam M Chaker⁸Luisa Azevedo^10,9Christian Von Buchwald¹¹Emilie Bequignon^12,13Eliza Brozek-Madry¹⁴Jannis Constantinidis¹⁵Marjolein Cornet¹⁶Wytske J Fokkens¹⁷Peter G Gibson^18,19,20Aleksander Grande Hansen²¹JOAQUIM MULLOL²²Sietze Reitsma¹⁷Sanna Katriina Toppila-Salmi^23,24,25Michael B Soyka²⁶Martin Wagenmann²⁷Peter W Hellings^28,29

• ¹Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
• ²A Gemelli University Hospital Foundation IRCCS, Rome, Italy
• ³Institute for Translational Research in Inflammation, Lille, France
• ⁴University of Crete School of Medicine, Heraklion, Crete, Greece
• ⁵Odense Universitetshospital, Odense, Denmark
• ⁶Syddansk Universitet, Odense, Denmark
• ⁷Universiteit Gent, Ghent, Belgium
• ⁸Technische Universitat Munchen, Munich, Germany
• ⁹Unidade Local de Saude da Regiao de Aveiro, Ovar, Portugal
• ¹⁰Egas Moniz Health Alliance Academic Clinical Center, Aveiro, Portugal
• ¹¹Kobenhavns Universitet, Copenhagen, Denmark
• ¹²Centre Hospitalier Intercommunal de Creteil, Créteil, France
• ¹³Universite Paris-Est Creteil Val de Marne, Créteil, France
• ¹⁴National Institute of the Ministry of the Interior and Administration, Warsaw, Poland
• ¹⁵Aristotle University of Thessaloniki, AHEPA Hospital, Thessalonkiki, Greece
• ¹⁶Alrijne Ziekenhuis Leiden, Leiden, Netherlands
• ¹⁷Amsterdam Universitair Medische Centra, Amsterdam, Netherlands
• ¹⁸University of Newcastle, New Lambton Heights, Australia
• ¹⁹John Hunter Hospital, New Lambton Heights, Australia
• ²⁰The University of Newcastle Hunter Medical Research Institute, New Lambton, Australia
• ²¹Lovisenberg Diakonale Hogskole, Oslo, Norway
• ²²Hospital Clinic de Barcelona, Barcelona, Spain
• ²³Ita-Suomen yliopisto, Joensuu, Finland
• ²⁴Wellbeing Services County of Pohjois-Savo, Kuopio, Finland
• ²⁵Helsinki University, Helsinki, Finland
• ²⁶UniversitatsSpital Zurich, Zürich, Switzerland
• ²⁷Universitatsklinikum Dusseldorf, Düsseldorf, Germany
• ²⁸University of Ghent, Leuven, Belgium
• ²⁹Katholieke Universiteit Leuven, Leuven, Belgium

Background Chronic rhinosinusitis with nasal polyps (CRSwNP) is a persistent inflammatory condition often associated with type 2 inflammation. While biologics are a promising treatment for patients with uncontrolled CRSwNP, real-world evidence is needed to optimize their use. The InternatioNal seVerE CRSwNP (INVENT) registry aims to consolidate data on biologic use in CRSwNP from local and national registries. This study describes the identification of mandatory and optional variables for inclusion in the INVENT registry using a modified Delphi process. Methods A narrative literature review was performed to identify variables reported in real-world studies of biologic treatment for CRSwNP. A modified Delphi study was conducted between December 2024 and March 2025 involving 23 experts from Europe and Australia. Experts rated the clinical relevance of candidate variables in two online survey rounds using 9-point Likert scales. A positive response was defined as ≥70% of respondents rating a variable 7–9 and ≤15% rating it 1–3. Final agreement on mandatory and optional variables was reached through panel discussion. A validation survey was then conducted across registry centers to assess the feasibility of collecting the selected variables. Results The Delphi process resulted in consensus on a core set of mandatory and optional variables across nine domains: demographics, medical history, previous and current biologic therapy, biomarkers, comorbidities, asthma, CRSwNP-specific outcomes, and follow-up variables. The validation survey confirmed that most mandatory variables were available or obtainable across participating centers, supporting the feasibility of data collection. Conclusions This international Delphi study identified a consensus-based set of clinically-relevant and feasible variables for inclusion in the INVENT registry. The selected variables reflect current best practices in the management of CRSwNP and will enable robust comparisons of biologic effectiveness in real-world settings. The INVENT registry is well-positioned to inform treatment decisions, optimize use of biologics, and support a personalized approach to CRSwNP care.