Disproportionality analysis of drug-associated progressive multifocal leukoencephalopathy using spontaneous reports: A 20-year signal detection study based on the FAERS database

This analysis identified 72 drugs with consistent PML reporting signals. However, these findings represent statistical associations in spontaneous reports, not causal relationships or true incidence rates. Inherent limitations-including underreporting, incomplete medication histories, and lack of exposure denominators-require cautious interpretation. Prospective validation studies are essential to establish causality and quantify absolute risks.