Development of a Tool to Measure the Clinical Response to Biologic Therapy in Uncontrolled Severe Asthma: The FEV₁, Exacerbations, Oral Corticosteroids, Symptoms Score

Background: There is a lack of tools to quantify the response to monoclonal antibodies (mAbs) holistically in severe uncontrolled asthma patients. Objective: To develop a valid score to assist specialists in this clinical context. Methods: The score was developed in four 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 using the Potentially All Pairwise RanKings of All Possible Alternatives methodology using the 1000minds software; and (4) face validity assessment of the obtained score. Results: Four core items, with different levels of response for each, were selected: severe exacerbations, oral corticosteroid use, symptoms (evaluated by Asthma Control Test), and bronchial obstruction (assessed by FEV₁ percent predicted). 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 a better response and the range of responses runs from 0 (worsening) to 100 (best possible response). Face validity was high (intraclass correlation coefficient of 0.86). Conclusions: The FEV₁, exacerbations, oral corticosteroids, symptoms score allows clinicians to quantify response in severe uncontrolled asthma patients who are being treated with mAbs.