The development and validation of the King's Brief Interstitial Lung Disease (K-BILD) health status questionnaire

Amit Patel, Richard Siegert, Katherine Brignall, Patrick Gordon, Sophia Steer, Sujal R. Desai, Toby M. Maher, Elisabetta A. Renzoni, Athol U. Wells, Irene J. Higginson, Surinder Birring

Research output: Contribution to journalArticlepeer-review

174 Citations (Scopus)

Abstract

Rationale: Health status is impaired in patients with interstitial lung disease (ILD). There is a paucity of tools that assess health status in ILD. The objective of this study was to develop and validate the King's Brief Interstitial Lung Disease questionnaire (K-BILD), a new health status measure for patients with ILD.

Methods: Patients with ILD were recruited from outpatient clinics. The development of the questionnaire consisted of three phases: item generation; item reduction, allocation to domains by factor analysis, Rasch analysis to create unidimensional scales and validation; and repeatability testing.

Results: 173 patients with ILD (49 with idiopathic pulmonary fibrosis) completed a preliminary 71-item questionnaire. 56 items were removed due to redundancy, low factor loadings or poor fit to the Rasch model. The final version of the K-BILD questionnaire consisted of 15 items and three domains (breathlessness and activities, chest symptoms and psychological). Internal consistency assessed with Cronbach's a coefficient was 0.94 for the K-BILD total score. Concurrent validity of the K-BILD questionnaire was high compared with St George's Respiratory Questionnaire (r=0.90) and moderate with lung function (vital capacity, r=0.50). The K-BILD questionnaire was repeatable over 2 weeks (n=44), with intraclass correlation coefficients for domains and total score 0.86-0.94. The K-BILD construct validity for patients with idiopathic pulmonary fibrosis was similar to that of other ILDs.

Conclusion: The K-BILD questionnaire is a brief, valid, self-completed health status measure for ILD. It could be used in the clinic to assess ILD from the patients' perspective.

Original languageEnglish
Pages (from-to)804-810
Number of pages7
JournalThorax
Volume67
Issue number9
DOIs
Publication statusPublished - Sept 2012

Fingerprint

Dive into the research topics of 'The development and validation of the King's Brief Interstitial Lung Disease (K-BILD) health status questionnaire'. Together they form a unique fingerprint.

Cite this