PT - JOURNAL ARTICLE AU - Hyland, Michael E AU - Jones, Rupert C AU - Lanario, Joseph W AU - Masoli, Matthew TI - The construction and validation of the Severe Asthma Questionnaire (SAQ) AID - 10.1183/13993003.00618-2018 DP - 2018 Jan 01 TA - European Respiratory Journal PG - 1800618 4099 - https://publications.ersnet.org//content/early/2018/05/17/13993003.00618-2018.short 4100 - https://publications.ersnet.org//content/early/2018/05/17/13993003.00618-2018.full AB - Background The USA's Food and Drug Administration's procedure for scale validation requires a documented stepwise process of qualitative and quantitative data. The aim of this paper is to provide the final quantitative validating data.Methods The severe asthma questionnaire (SAQ), asthma control test (ACT), MiniAQLQ, and EQ-5D-5L were completed by 160 patients attending a severe asthma clinic; 51 patients completed the SAQ on two occasions for test-retest reliability analysis. The SAQ produces two scores, an SAQ score based on the average of 16 items and a SAQ-global score from a single 100-point global quality of life scale.Results Construct validity was demonstrated through factor analysis of the 16 items, convergent validity by correlations of > 0.6 between the SAQ, SAQ-global and other questionnaires, and discriminant validity by the ability of the SAQ and SAQ-global to distinguish between different treatment levels. Test-retest reliability (intra-class correlation) was 0.93 for the SAQ and 0.93 for the SAQ-global, and the alpha coefficient for the SAQ was 0.93.Conclusions The SAQ was developed using recommended qualitative and quantitative procedures for scale development, and can be used to gain insight into patients’ perceptions of the impact of severe asthma and its treatment on their lives.This paper describes the validation process for a new severe asthma specific quality of life questionnaire, the SAQFootnotesThis manuscript has recently been accepted for publication in the European Respiratory Journal. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article.Conflict of interest: Dr. Hyland reports grants from Novartis, grants from AstraZenca, during the conduct of the study; personal fees from Novartis, personal fees from GSK, outside the submitted work.Conflict of interest: Dr. Jones reports grants from Novartis, grants from AstraZeneca, during the conduct of the study; personal fees from GlaxoSmithKline, personal fees from AstraZeneca, personal fees from Boehringer-Ingelheim, personal fees from Chiesi, personal fees from Cipla, personal fees from Novartis , personal fees from Pfizer, outside the submitted work.Conflict of interest: Dr. Lanario reports grants from Novartis, grants from AstraZeneca, during the conduct of the study; personal fees from Novartis, outside the submitted work.Conflict of interest: Dr. Masoli reports unrestricted non-promotional grants from Novartis and Astra Zenenca which have supported the initial study of patient interviews and questionnaire development. The SAQ validation study has been supported through Plymouth hospitals NHS Trust research fund. During the conduct of the study Dr Masoli has received personal fees from Novartis and Astra Zeneca, outside the submitted work; .