Abstract
Introduction and aim: The K-BILD is a validated 15-item questionnaire assessing health status in patients with Interstitial Lung Disease (ILD) that is increasingly used in trials and clinical practice as it is disease specific and short. Because responsiveness data of the K-BILD are limited, we studied the changes over time of the K-BILD compared to other health status measures.
Methods: Consecutive outpatients with ILD at the Erasmus MC, were asked to complete K-BILD, Saint George's Respiratory Questionnaire (SGRQ), generic EQ5D and Punum Ladders at baseline and 6 months. We analyzed the change in K-BILD total score over time and compared this to the other measures. The minimally important difference (MID) for the K-BILD total score is 8 units. This MID was used to identify subgroups with minimally important improvement or decline. Correlations were assessed using Pearson's correlations coefficients.
Background: Eighty-one patients were included; 41 females (51%), mean (range) age 63 (36-83) years, with a baseline K-BILD total score of 58 (14-99). The correlations between change in K-BILD total score and other measures were respectively r=-0.63 for the SGRQ total score, r=0.44 for the EQ5D VAS and r=-0.31 for the Punum Ladder. At 6 months, 43 patients had a change > than MID (8 units).
For subgroups based on K-BILD's MID score, the mean change was consistent with the direction and magnitude of the mean change in SGRQ total score and direction of the other outcome measures.
Conclusion: K-BILD showed high agreement in changes in health status with SGRQ but less with generic health status measurements.
- Copyright ©the authors 2016
