Minimum important difference of the EQ-5D-5L and EQ-VAS in fibrotic interstitial lung disease Journal Articles uri icon

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  • RationaleThe European Quality of Life 5-Dimensions 5-Levels questionnaire (EQ-5D-5L) is a multidimensional patient-reported questionnaire that supports calculation of quality-adjusted life-years. Our objectives were to demonstrate feasibility of use and to calculate the minimum important difference (MID) of the EQ-5D-5L and its associated visual analogue scale (EQ-VAS) in patients with fibrotic interstitial lung disease (ILD).MethodsPatients who completed the EQ-5D-5L were identified from the prospective multicentre CAnadian REgistry for Pulmonary Fibrosis. Validity, internal consistency and responsiveness of the EQ-5D-5L were assessed, followed by calculation of the MID for the EQ-5D-5L and EQ-VAS. Anchor-based methods used an unadjusted linear regression against pulmonary function tests (PFTs) and dyspnoea and other quality of life questionnaires. Distribution-based method used one-half SD and SE measurement (SEM) calculations.Results1816 patients were analysed, including 472 (26%) with idiopathic pulmonary fibrosis. EQ-5D-5L scores were strongly correlated with the dyspnoea and other quality of life questionnaires and weakly associated with PFTs. The estimated MID for EQ-5D-5L ranged from 0.0050 to 0.054 and from 0.078 to 0.095 for the anchor-based and distribution-based methods, respectively. The MID for EQ-VAS ranged from 0.5 to 5.0 and from 8.0 to 9.7 for the anchor-based and distribution-based methods. Findings were similar across ILD subtypes, sex and age.ConclusionWe used a large and diverse cohort of patients with a variety of fibrotic ILD subtypes to suggest validity and MID of both the EQ-5D-5L and EQ-VAS. These findings will assist in designing future clinical trials and supporting cost-effectiveness analyses of potential treatments for patients with fibrotic ILD.


  • Tsai, Amy Po Yu
  • Hur, Seo Am
  • Wong, Alyson
  • Safavi, Mohsen
  • Assayag, Deborah
  • Johannson, Kerri A
  • Morisset, Julie
  • Fell, Charlene
  • Fisher, Jolene H
  • Manganas, Hélène
  • Shapera, Shane
  • Cox, Gerard
  • Gershon, Andrea S
  • Hambly, Nathan
  • Khalil, Nasreen
  • To, Teresa
  • Wilcox, Pearce George
  • Halayko, Andrew
  • Kolb, Martin Rainer
  • Ryerson, Christopher J

publication date

  • January 2021

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