RT Journal Article SR Electronic T1 Is being able to walk to the letterbox life-changing? A qualitative assessment of measures of improvement in persistent breathlessness JF ERJ Open Research JO erjor FD European Respiratory Society SP 00530-2022 DO 10.1183/23120541.00530-2022 VO 9 IS 2 A1 Diana H. Ferreira A1 Magnus Ekström A1 Cornelia Verberkt A1 Daisy J.A. Janssen A1 David C. Currow YR 2023 UL http://openres.ersjournals.com/content/9/2/00530-2022.abstract AB