Berry JG, Ryan P, Braunack-Mayer AJ, Duszynski KM, Xafis V, Gold MS; Vaccine Assessment Using Linked Data (VALiD) Working Group. A randomised controlled trial to compare opt-in and opt-out parental consent for childhood vaccine safety surveillance using data linkage: study protocol. Trials. 2011 Jan 04;12():1. PMID: 21199584; PMCID: PMC3022742.
A randomised controlled trial to compare opt-in and opt-out parental consent for childhood vaccine safety surveillance using data linkage: study protocol