Barber, C, Azim, A, Newell, C, Kyyaly, A, Rupani, H, Haitchi, H M, Howarth, P & Kurukulaaratchy, R J 2022, ' Validation and further insight into the International Severe Asthma Registry (ISAR) eosinophil gradient algorithm in the Wessex AsThma CoHort of difficult asthma (WATCH) using historical blood eosinophil counts and induced sputum ', Clinical and Experimental Allergy, vol. 52, no. 6, pp. 792-796 . https://doi.org/10.1111/cea.14109