Assessing exertional dyspnea in patients with idiopathic pulmonary fibrosis.

Published

Journal Article

BACKGROUND: Dyspnea is a hallmark symptom of idiopathic pulmonary fibrosis (IPF), and dyspnea induced physical activity limitation is a prominent driver of quality of life impairment among IPF patients. METHODS: We examined response data for the 21 physical activity items (the first 21 of 24) from the University of California San Diego Shortness of Breath Questionnaire (UCSD) collected at baseline in a recently conducted IPF trial. We used Rasch analysis and hypothesis testing with conventional statistical methodology to achieve three objectives: 1) to examine the items to identify the one characteristic that distinguishes one from another; 2) to asses these items for their ability to measure dyspnea severity in IPF; 3) to use the items to develop a dyspnea ruler. RESULTS: The sample comprised 178 subjects. The 21 items fit the Rasch model. There was very strong correlation between Rasch item severity and their metabolic equivalents (METS) values (r = -0.86, p < 0.0001). With the sample stratified on scores from the 21 items, there were significant between group differences in FVC%, DLCO% and distance walked during the six-minute walk test. The dyspnea ruler can be used to put dyspnea levels in a more easily understood clinical context. CONCLUSIONS: The first 21 items from the UCSD compose a unidimensional dyspnea-with-activity scale and are both sensibly ordered and distinguished from each other by their METS values. These 21 items can be used confidently to formulate clinically-relevant inferences about IPF patients and should be considered for use as a meaningful endpoint in IPF research.

Full Text

Duke Authors

Cited Authors

  • Swigris, JJ; Streiner, DL; Brown, KK; Belkin, A; Green, KE; Wamboldt, FS; IPFnet Investigators,

Published Date

  • January 2014

Published In

Volume / Issue

  • 108 / 1

Start / End Page

  • 181 - 188

PubMed ID

  • 24388667

Pubmed Central ID

  • 24388667

Electronic International Standard Serial Number (EISSN)

  • 1532-3064

Digital Object Identifier (DOI)

  • 10.1016/j.rmed.2013.12.009

Language

  • eng

Conference Location

  • England