Quality of life instruments in idiopathic pulmonary fibrosis: a COSMIN-based systematic review

This systematic review aims to systematically evaluate the methodological quality and measurement properties of existing quality-of-life assessment tools for patients with idiopathic pulmonary fibrosis, and to provide evidence-based recommendations for instrument selection in clinical research and practice.

A comprehensive computer search was conducted in PubMed, Embase, Web of Science, CINAHL, CNKI, Wanfang, VIP, and the Chinese Biomedical Literature Database from January 1, 2010 to December 28, 2025. Studies evaluating the measurement properties of IPF-specific quality of life tools published in Chinese or English were included. Two researchers independently screened the literature and extracted data, while four researchers assessed the methodological quality and measurement properties of the included studies according to the Consensus-Based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines.The modified Grading of Recommendations Assessment Development and Evaluation (GRADE) method was employed to grade the certainty of evidence, and based on this grading along with team consensus, recommendations were formulated.

A preliminary search identified 1923 records (6 Chinese, 1917 English). After removing duplicates, 910 records remained; 840 were excluded by title and abstract screening, and the remaining 70 full texts were assessed. Ultimately, 11 documents were included, encompassing 9 assessment tools. The evaluation of methodological quality revealed that most tools had methodological shortcomings, particularly in content validity, cross‑cultural validity, measurement error, and criterion validity. Following the evidence grading, none of the nine tools met the standards for Category A recommendations; all were classified as Category B recommendations. Notably, the IPF-PRO scale demonstrated higher evidence quality in terms of internal consistency, structural validity, hypothesis testing, and other measurement attributes, leading to its provisional recommendation for use.

The IPF-PRO scale demonstrates high methodological quality in its validation study for structural validity and internal consistency, with the evidence for these properties graded as "High" by the modified GRADE approach. However, its structural validity results were rated as "indeterminate" by COSMIN criteria, indicating that the statistical findings did not fully meet the criteria for "sufficient" evidence. Content validity was graded as "Moderate" and criterion validity as "Low". Therefore, while the IPF-PRO scale shows promise and is provisionally recommended for use in Chinese clinical settings with appropriate caveats, further validation is needed to confirm its structural validity and to evaluate its measurement error and responsiveness.