Abstract
Introduction: The K-BILD is a validated HRQOL questionnaire. We previously reported the MID is 8 units. Item responses are now transformed to logits rather than using raw responses, as this is potentially a more linear scale (Patel A, JCE 2015;68;1019). The aim of this study was to re-evaluate the K-BILD MID using the logit scale.
Methods: 57 patients with ILD (17-IPF) completed the K-BILD on 2 occasions. At the second visit patients also completed a Global rating of change of health status questionnaire (GRCQ). The MID was calculated as the mean of 4 different methods (anchors): GRCQ, 7-12% change in FVC, 1 SEM and effect size (ES) of 0.3.
Results: The mean(SD) K-BILD Total score for all patients was 55.3(15.6). 36 patients reported a change in their condition on the GRCQ. There was a significant change in K-BILD score in patients reporting a change in GRCQ; mean(SD) 57.0(13.6) vs. 50.0(9.7); mean diff 7.0; 95% CI 3.0 to 11.0; p<0.01. The change in K-BILD score correlated with the GRCQ; r=-0.49, p<0.01. The mean(range) K-BILD total score MID was 5(4-7).
| MID Anchor | Mean MID | ||||
| GRCQ | FVC 7-12% | 1 SEM | ES 0.3 | ||
| K-BILD Psychological | 5.3 (17.8) | 7.4 (5.6) | 5.8 | 5.8 | 6 |
| K-BILD Breathlessness and Activities | 8.3 (18.3) | 6.9 (12.0) | 6.9 | 6.1 | 7 |
| K-BILD Chest | 11.2 (19.4) | 13.7 (21.5) | 12.3 | 7.1 | 11 |
| K-BILD Total | 6.7 (13.2) | 6.1 (7.0) | 3.8 | 4.7 | 5 |
Conclusion: In conclusion K-BILD is a responsive tool for longitudinal assessment of HRQOL in patients with ILD. The MID of the K-BILD Total score is a 5 unit change.
- Copyright ©the authors 2016
