Methods

Steering committee and expert meeting attendees

A steering committee (SC) was formed that comprised seven experts from across the Nordic region who were invited by Sanofi Genzyme based on their expertise in their respective fields related to the treatment of patients with type 2 inflammatory diseases. The SC members included one allergist and clinical immunologist from Iceland, two dermatologists from Denmark, one ENT specialist from Finland, one paediatrician from Finland and two pulmonologists from Sweden and Denmark, respectively. In addition to the SC, 23 experts (dermatologists [n = 10], pulmonologists [n = 7], ENT specialists [n = 3], internal medicine specialists/clinical immunologists/allergists [n = 2] and a paediatrician) from across the Nordic region (Sweden [n = 8], Finland [n = 6], Denmark [n = 5], Norway [n = 3] and Estonia [n = 1]) were invited to participate. All were considered widely recognised experts in their fields at least at a regional level.

Scope

The SC determined the scope of this initiative, which investigated the extent of overlap between diseases that may be driven by type 2 inflammation (asthma, atopic dermatitis, CRSwNP, eosinophilic esophagitis and chronic rhinitis). There are other relevant conditions, such as food allergy and chronic urticaria, that were not included.

Literature search

To improve the knowledge base for the discussion, a non-systematic literature search was performed using the PubMed database to identify published work related to the objectives of this study and to identify needs for consensus. The literature search was conducted between January and June 2020 and included multiple combinations of the following search terms: ‘atopic dermatitis’, ‘atopic eczema’, ‘childhood eczema’, ‘paediatric eczema’, ‘asthma’, ‘rhinitis’, ‘eosinophilic esophagitis’, ‘chronic rhinosinusitis’ and ‘polyps’, with ‘morbidities’ added as a qualifier. Searches for ‘atopic march’ and ‘allergic rhinitis and its impact on asthma (ARIA)’ were also conducted. Publications were only considered if they were written in English, had a human/clinical focus and were published after 1 January 2005.
The most relevant papers were identified based on review of abstracts; relevant data regarding the prevalence of overlap between type 2 inflammatory conditions were extracted and tabulated according to primary diagnosis. Reference lists of key papers and papers of interest provided by the SC were also reviewed.

Modified Delphi process

The Delphi process is a recognised facilitation technique used to obtain consensus between specialists in a particular field where expert opinion is important for clinical guidance, especially if limited evidence is available.48 This approach provides experts with the opportunity to alter their response based on their peers’ opinions, thus increasing the likelihood for opinions to converge. The modified Delphi process used in this initiative is outlined in Figure 2.