Cross-Atlantic modification and validation of the A Tool to assess quality of life in idiopathic pulmonary fibrosis (ATAQ-IPF-cA)

Yorke, J; Spencer, LG; Duck, A; Ratcliffe, SM; Kwong, GN; Longshaw, MS; Belkin, A; Swigris, JJ

Abstract

Rationale: The A Tool to Assess Quality of Life in Idiopathic Pulmonary Fibrosis (ATAQ-IPF) was developed in the USA to assess health-related quality of life in patients with IPF. It is likely that some of the original ATAQ-IPF items perform differently when applied in different countries. This paper reports results of a study conducted to identify the need to refine the content of the ATAQ-IPF to minimise cross-country bias between the USA and the UK.

Methods: The ATAQ-IPF and other study measures were completed by patients attending specialist IPF clinics in the USA and UK. Rasch analysis was used to determine which items performed differently across countries (USA vs UK) and refine the original ATAQ-IPF to an instrument without cross-country bias (ATAQ-IPF-cA). Preliminary validation of the modified instrument was examined by assessing correlations between ATAQ-IPF-cA scores and scores from dyspnoea-specific patient-reported outcome (PRO) measures.

Results: 139 patients with IPF (USA=74; UK=65) participated in the study. A total of 41 items and 4 domains were removed from the original, 86-item instrument to yield the 43 items and 10 domains of the ATAQ-IPF-cA. Each domain had good fit to the Rasch model, internal consistency was comparable to the corresponding domains for the original ATAQ-IPF, and validity was supported by significant correlations between its scores and scores from dyspnoea-specific PROs.

Conclusions: The reliability and validity of the substantially shortened ATAQ-IPF-cA are acceptable and comparable to the original instrument. We recommend use of the ATAQ-IPF-cA in IPF studies in which participants are enrolled from the USA and UK.

Citation

Yorke, J., Spencer, L., Duck, A., Ratcliffe, S., Kwong, G., Longshaw, M., …Swigris, J. (2014). Cross-Atlantic modification and validation of the A Tool to assess quality of life in idiopathic pulmonary fibrosis (ATAQ-IPF-cA). BMJ Open Respiratory Research, 1, e000024-e000024. https://doi.org/10.1136/bmjresp-2014-000024

• Journal Article Type: Article
• Acceptance Date: Apr 16, 2014
• Online Publication Date: May 14, 2014
• Publication Date: May 14, 2014
• Deposit Date: Jun 12, 2015
• Publicly Available Date: Apr 5, 2016
• Journal: BMJ Open Respiratory Research
• Electronic ISSN: 2052-4439
• Publisher: BMJ Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 1
• Pages: e000024-e000024
• DOI: https://doi.org/10.1136/bmjresp-2014-000024
• Publisher URL: http://dx.doi.org/10.1136/bmjresp-2014-000024
• Related Public URLs: http://bmjopenrespres.bmj.com/
• Additional Information: Grant Number: BLF (TC08/6); Grant Number: K23 HL092227