Meta-analysis was performed using RevMan 5.4 software. 
RevMan 5.4
We searched the Cochrane Library, PubMed, Web of Science, and Embase databases for all randomized controlled trials (RCTs) and observational studies (cohort or case-control studies) that compare PCVP to PVP/KP for OVCFs. 
Cochrane Library
We searched the Cochrane Library, PubMed, Web of Science, and Embase databases for all randomized controlled trials (RCTs) and observational studies (cohort or case-control studies) that compare PCVP to PVP/KP for OVCFs. 
PubMed
We searched the Cochrane Library, PubMed, Web of Science, and Embase databases for all randomized controlled trials (RCTs) and observational studies (cohort or case-control studies) that compare PCVP to PVP/KP for OVCFs. 
Web of Science
We searched the Cochrane Library, PubMed, Web of Science, and Embase databases for all randomized controlled trials (RCTs) and observational studies (cohort or case-control studies) that compare PCVP to PVP/KP for OVCFs. 
Embase databases