The King's brief interstitial lung disease (K-BILD) questionnaire; an updated minimal important difference - Sinha, A; Patel, AS; Siegert, R; Bajwah, S; Keir, G; Gordon, P; Steer, S; Maher, TM; Renzoni, EA; Wells, AU; Higginson, IJ; Birring, SS (EUROPEAN RESPIRATORY SOC JOURNALS LTD, 2016)