Association of preserved ratio impaired spirometry with mortality: a systematic review and meta-analysis.

"Conflict of interest: All authors have nothing to disclose."

"Support statement: The work described in this paper was substantially supported by a grant (identifier 171799592) from the Pneumoconiosis Compensation Fund Board (PCFB) of Hong Kong and the Faculty Postdoctoral Fellowship Scheme (identifier FPFS/21-22/08) by Faculty of Medicine, The Chinese University of Hong Kong. The funding sources had no role in the study design, data collection, statistical analyses, result interpretation and manuscript preparation. Funding information for this article has been deposited with the Crossref Funder Registry."

"The protocol of this study is registered at www.crd.york.ac.uk/prospero (registration number CRD42023408252). The present study is reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis reporting guideline []."