fig1

Figure 1. Flowchart of Literature Screening. This PRISMA flowchart outlines the systematic selection process of relevant literature. A total of 1,155 studies were identified through initial database searches, with 427 duplicates removed. After screening titles and abstracts, 728 records were reviewed, and 119 full-text articles were assessed for eligibility. Thirty-eight studies met the inclusion criteria for the meta-analysis, focusing on PEP risk factors in the Chinese population. Excluded studies were those with non-relevant outcomes, non-Chinese cohorts, or insufficient data.