Psychometric Properties and Prognostic Value of the UCSD Shortness of Breath Questionnaire in Hypersensitivity Pneumonitis: A Prospective Cohort Study

RationaleDyspnea is a prominent symptom of hypersensitivity pneumonitis (HP), limiting patients activity and impairing their quality of life. The University of California San Diego Shortness of Breath questionnaire (UCSD) is a 24-item instrument used to assess dyspnea severity in patients with various respiratory conditions. ObjectiveTo examine the psychometric properties of the UCSD and assess the validity of its scores as measures of dyspnea severity and prognostic value in a prospective cohort with HP. MethodsWe evaluated the reliability, validity, and responsiveness of UCSD scores and assessed the association between score change and survival in a cohort of patients with HP who completed the UCSD and other HP severity metrics at baseline, 6 and 12 months. We introduce the reliable change index (RCI) and the likely change index (LCI) as ways to assess the statistical significance of within-individual change in UCSD scores and conducted analyses to provide context. ResultsAt baseline, internal consistency (Cronbachs coefficient alpha) was 0.97; there were significant, moderately strong correlations between UCSD scores and percent predicted forced vital capacity (FVC%) r = -0.39, percent predicted diffusing capacity of the lung for carbon monoxide (DLCO%) r = -0.33), and Borg dyspnea scores (0.55). UCSD scores were significantly different between the lowest and highest FVC%, 64.9 {+/-} 18.9 vs. 36.2 {+/-} 22.9. A 10- point worsening in the UCSD score was associated with a nearly 15-fold increase in time-to-death over the follow-up period. ConclusionThe UCSD has acceptable psychometric properties for assessing dyspnea severity in patients with HP. Worsening dyspnea is associated with shortened survival.