Q. On the PRISMA diagram it lists Registers, what are Registers?

A register in PRISMA refers to a database or other source that contains records of ongoing or completed studies that have not yet been published. These registers can include trial registries, conference proceedings, and grey literature sources, among others. The inclusion of register searching is recommended in systematic reviews to identify relevant studies that may not have been published yet, reducing the risk of publication bias. (Rayyan, 2022)

For more information, go to https://apu.libguides.com/clinicaltrials