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Rationale: A visual analog scale (VAS) is a simple and easily administered tool for measuring the impact of disease; however, little is known about the use of a dyspnea VAS in interstitial lung disease (ILD). Objectives: To validate the use of a dyspnea VAS in a large and heterogeneous cohort of patients with fibrotic ILD, including its minimal clinically important difference (MCID), responsiveness to change, and prognostic significance. Methods: Patients with fibrotic ILD were identified from a large prospective registry. The validity of a 100-mm dyspnea VAS was assessed by testing its correlation in change score with other measures of ILD severity, including the University of California San Diego Shortness of Breath Questionnaire, the King's Brief Interstitial Lung Disease quality of life questionnaire Breathlessness and Activities Domain, the European Quality of Life VAS, forced vital capacity, and diffusing capacity of the lung for carbon monoxide. The responsiveness of the dyspnea VAS was qualitatively confirmed on the basis of there being an observable difference in the change in dyspnea VAS across tertiles of change in anchor variables. The MCID in dyspnea VAS was calculated using both anchor (linear regression) and distribution (one-half standard deviation) approaches, with anchors including the above variables that had a correlation with dyspnea VAS (|r| ≥ 0.30). The association of dyspnea VAS with time to death or transplant was determined. Results: The cohort included 826 patients with fibrotic ILD, including 127 patients with follow-up measurements at 6 months. The mean baseline dyspnea VAS was 53 ± 24 mm. Dyspnea VAS change scores were moderately correlated with the University of California San Diego Shortness of Breath Questionnaire (|r| = 0.55) and the King's Brief Interstitial Lung Disease quality of life questionnaire Breathlessness and Activities Domain (|r| = 0.44) and weakly correlated with the European Quality of Life VAS (|r| = 0.19), forced vital capacity percent predicted (|r| = 0.21), and diffusing capacity of the lung for carbon monoxide percent predicted (|r| = 0.05). The MCID was 2.7 to 4.5 using the more reliable anchor-based methods and 12.0 based on distribution-based methods. Dyspnea VAS was associated with time to death or transplant in unadjusted models and after adjustment for age and sex (hazard ratios, 1.16 and 1.15, respectively; P < 0.05 for both). Conclusions: This study provides support for the use of the dyspnea VAS in patients with fibrotic ILD, with an estimated anchor-based MCID of 5 mm. [ABSTRACT FROM AUTHOR]

Rationale: Multimorbidity is common and leads to substantial concomitant medication burden in patients with interstitial lung disease (ILD), which may affect tolerability of ILD-targeted medications and health outcomes. Objectives: To determine the associations of concomitant medication burden with tolerability of ILD-targeted medications and survival in patients with idiopathic pulmonary fibrosis (IPF) and non-IPF ILD. Methods: Patients with IPF receiving nintedanib or pirfenidone and patients with non-IPF ILD receiving azathioprine or mycophenolate were identified from two Australian and Canadian registries. Baseline concomitant medication burden was evaluated using three measures: medication count, polypharmacy (⩾5 medications), and the medication regimen complexity index (MRCI). Medication intolerance and discontinuation were evaluated at 6 months and 1 year after initiation of ILD-targeted medications, respectively. Cox regression models and likelihood ratio tests were used to determine the prognostic significance of medication burden on transplant-free survival. Results: In 645 treated patients with IPF, 43% experienced adverse reactions leading to intolerance (defined as dose reduction, temporary dose interruption, or permanent drug discontinuation) of antifibrotic medications within 6 months of initiation, with high baseline concomitant medication burden being consistently associated with intolerance (medication count: P = 0.005; polypharmacy: P = 0.006; MRCI: P = 0.004). This association was not observed for immunosuppressive medications in 1,255 treated patients with non-IPF ILD, who also had a lower intolerance (18%). Baseline concomitant medication burden was not independently associated with permanent discontinuation of antifibrotic (29%) and immunosuppressive medications (20%) at 1 year. The MRCI was the only measure of concomitant medication burden associated with transplant-free survival in both cohorts (P < 0.01 for both), which improved prognostication beyond common clinical factors and the ILD-GAP index (P < 0.001 for both). Conclusions: Concomitant medication burden is associated with intolerance of antifibrotic medications in patients with IPF. Medication regimen complexity is superior to simpler evaluation of concomitant medication burden for predicting prognosis in ILD. [ABSTRACT FROM AUTHOR]