PSYCHOMETRIC VALIDATION OF THE EQ-5D-5L BREATHING BOLT-ON IN A US-BASED LONGITUDINAL COHORT WITH ASTHMA AND COPD
Author(s)
Aaron N. Winn, MPP, PhD1, Annika Louise Pickard, MS2, Esther Pacheco, MS3, Min Joo, MS MS3, A Simon Pickard, PhD4.
1Associate Professor, University of Illinois at Chicago, Chicago, IL, USA, 2UIC College of Pharmacy, Chicago, IL, USA, 3University of Illinois at Chicago, Chicago, IL, USA, 4University of Illinois, Chicago, Chicago, IL, USA.
1Associate Professor, University of Illinois at Chicago, Chicago, IL, USA, 2UIC College of Pharmacy, Chicago, IL, USA, 3University of Illinois at Chicago, Chicago, IL, USA, 4University of Illinois, Chicago, Chicago, IL, USA.
OBJECTIVES: The EQ-5D-5L Breathing bolt-on (EQ-5D-5L+BR) was developed to capture respiratory-specific HRQoL, but evidence on its psychometric performance, particularly longitudinally, remains limited. We evaluated its psychometric properties in a prospective cohort of adults with asthma and/or COPD.
METHODS: We conducted a secondary analysis of the REDEFINE cluster-randomized trial (N=402), following adults with clinician-diagnosed asthma and/or COPD across five waves over 12 months. The EQ-5D-5L and Breathing bolt-on were self-administered at each wave. Analyses assessed convergent validity (Spearman correlations with the COPD Assessment Test [CAT] and mMRC dyspnea scale; incremental R² predicting EQ-VAS), known-groups validity (ordinal regression and Cliff's delta by prior hospitalization), structural validity (confirmatory factor analysis, WLSMV), informativity (unique health-state counts for five- vs six-dimension systems), and responsiveness (using mMRC change, steroid use, and a respiratory symptom item as anchors).
RESULTS: Participants’ mean age was 58.8 years (33% women; 50% non-white). The bolt-on showed strong convergent validity (r=0.554 with CAT) and known-groups validity for prior lung-related hospitalization (Cliff's δ=-0.318; 95% CI -0.455 to -0.167). Confirmatory factor analysis confirmed meaningful loading on the general HRQoL factor (λ=0.63, p<0.001); a modest fit decline when adding the bolt-on (ΔCFI=-0.013) indicated partial distinctiveness from core dimensions. The bolt-on increased unique health states by 43% (161 to 230), with largest gains in the more severe FEV₁ group. Responsiveness was limited in this stable sample: only one significant anchor-based correlation (mMRC change at 6 months; r=0.143, p=0.006), non-significant Kruskal-Wallis tests (p=0.108-0.664), and steroid-related fluctuations below the 0.50 half-SD threshold.
CONCLUSIONS: The EQ-5D-5L Breathing bolt-on shows strong convergent and known-groups validity in a racially diverse, community-based respiratory cohort and meaningfully improves the EQ-5D's descriptive richness. Structural analyses suggest a partially distinct respiratory dimension. Limited responsiveness in this stable outpatient setting highlights the importance of sample selection and anchor choice, a methodological insight relevant to the EuroQol Bolt-On Toolbox initiative.
METHODS: We conducted a secondary analysis of the REDEFINE cluster-randomized trial (N=402), following adults with clinician-diagnosed asthma and/or COPD across five waves over 12 months. The EQ-5D-5L and Breathing bolt-on were self-administered at each wave. Analyses assessed convergent validity (Spearman correlations with the COPD Assessment Test [CAT] and mMRC dyspnea scale; incremental R² predicting EQ-VAS), known-groups validity (ordinal regression and Cliff's delta by prior hospitalization), structural validity (confirmatory factor analysis, WLSMV), informativity (unique health-state counts for five- vs six-dimension systems), and responsiveness (using mMRC change, steroid use, and a respiratory symptom item as anchors).
RESULTS: Participants’ mean age was 58.8 years (33% women; 50% non-white). The bolt-on showed strong convergent validity (r=0.554 with CAT) and known-groups validity for prior lung-related hospitalization (Cliff's δ=-0.318; 95% CI -0.455 to -0.167). Confirmatory factor analysis confirmed meaningful loading on the general HRQoL factor (λ=0.63, p<0.001); a modest fit decline when adding the bolt-on (ΔCFI=-0.013) indicated partial distinctiveness from core dimensions. The bolt-on increased unique health states by 43% (161 to 230), with largest gains in the more severe FEV₁ group. Responsiveness was limited in this stable sample: only one significant anchor-based correlation (mMRC change at 6 months; r=0.143, p=0.006), non-significant Kruskal-Wallis tests (p=0.108-0.664), and steroid-related fluctuations below the 0.50 half-SD threshold.
CONCLUSIONS: The EQ-5D-5L Breathing bolt-on shows strong convergent and known-groups validity in a racially diverse, community-based respiratory cohort and meaningfully improves the EQ-5D's descriptive richness. Structural analyses suggest a partially distinct respiratory dimension. Limited responsiveness in this stable outpatient setting highlights the importance of sample selection and anchor choice, a methodological insight relevant to the EuroQol Bolt-On Toolbox initiative.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
PCR198
Topic
Methodological & Statistical Research, Patient-Centered Research
Topic Subcategory
Instrument Development, Validation, & Translation, Patient-reported Outcomes & Quality of Life Outcomes
Disease
Respiratory-Related Disorders (Allergy, Asthma, Smoking, Other Respiratory)