Patient-reported outcomes to assess dyspnoea in interstitial lung disease and pulmonary hypertension: a systematic literature review of measurement properties

OBJECTIVE: This COnsensus-based Standards for the selection of health measurement INstruments (COSMIN)-based systematic review aims to identify and summarise the quality of measurement properties of dyspnoea-specific patient-reported outcome measures (PROMs) for patients with interstitial lung disease (ILD), pulmonary hypertension (PH) or connective tissue diseases (CTDs). METHODS AND RESULTS: Relevant articles in PubMed and Embase were screened. Based on COSMIN analysis and the Grading of Recommendations, Assessment, Development and Evaluation approach, overall rating and level of evidence were assessed to formulate recommendations. We identified 26 publications on 10 PROMs. For patients with ILD, including CTD-associated ILD, nine PROMs were evaluated, of which the Dyspnea-12 (D12), EXACT-Respiratory Symptoms Idiopathic Pulmonary Fibrosis Breathlessness subscale (ERS-IPF-B), King's Brief Interstitial Lung Disease Health Status Questionnaire breathlessness and activities subscale (KBILD-B) and the University of California San Diego Shortness of Breath Questionnaire (UCSD-SOBQ) had high-quality evidence for sufficient internal consistency, without high-quality evidence of insufficient measurement properties. We reached this same conclusion regarding the D12 for use in patients with PH, including CTD-associated PH. Most PROMs in this systematic review have moderate- or low-quality evidence on construct validity and responsiveness. CONCLUSION: Four dyspnoea-specific PROMs, D12, ERS-IPF-B, KBILD-B and UCSD-SOBQ, can be recommended for use in patients with ILD, including CTD-associated ILD. Of these four, the D12, despite the limited evidence and the lack of evidence on several important domains, is also suitable for use in patients with PH, including CTD-associated PH.