RT Journal Article SR Electronic T1 Development of a tool to measure the clinical response to biologic therapy in uncontrolled severe asthma: the FEOS score JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA1098 DO 10.1183/13993003.congress-2021.PA1098 VO 58 IS suppl 65 A1 Veiga Teijeiro, Iria A1 Guzmán Peralta, Indhira A1 Pérez De Llano, Luis A1 Martín Robles, Irene A1 Blanco Cid, Nagore A1 Dacal Rivas, David A1 Davila, Ignacio A1 Martínez-Moragón, Eva A1 Domínguez Ortega, Javier A1 Almonacid, Carlos A1 Colás, Carlos A1 García-Rivero, Juan Luis A1 Carmona, Loreto A1 García De Yébenes, María Jesús A1 García-Cosío, Borja YR 2021 UL http://erj.ersjournals.com/content/58/suppl_65/PA1098.abstract AB Background: There is a lack of tools to holistically quantify the response to monoclonal antibodies (mAbs) in severe uncontrolled asthma (SUA) patients. The aim of this study was to develop a valid score to assist specialists in this clinical context.Methods: The score was developed in 4 subsequent phases: (1) elaboration of the theoretical model of the construct intended to be measured (response to mAbs); (2) definition and selection of items and measurement instruments by Delphi survey; (3) weight assignment of the selected items by multicriteria decision analysis (MCDA) using the Potentially All Pairwise RanKings of all possible Alternatives (PAPRIKA) methodology via the 1000Minds software; and (4) face validity assessment of the obtained score.Results: Four core items, with different levels of response for each of them, were selected: “severe exacerbations”, “oral corticosteroid use”, “symptoms” (evaluated by Asthma Control Test: ACT) and “bronchial obstruction” (assessed by FEV1% theoretical). “Severe exacerbations” and “oral corticosteroid maintenance dose” were weighted most heavily (38% each), followed by “symptoms” (13%) and “FEV1” (11%). Higher scores in the weighted system indicate better response and the range of responses runs from 0 (worsening) to 100 (best possible response). Face validity was high (intraclass correlation coefficient: 0.86).Conclusions: The FEOS score (FEV1, Exacerbations, Oral corticosteroids, Symptoms) allows clinicians to quantify response in SUA patients who are being treated with mAbs.FootnotesCite this article as: European Respiratory Journal 2021; 58: Suppl. 65, PA1098.This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).