A rapid research needs appraisal methodology to identify evidence gaps to inform clinical research priorities in response to outbreaks-results from the Lassa fever pilot. - Sigfrid, Louise; Moore, Catrin; Salam, Alex P.; Maayan, Nicola; Hamel, Candyce; Garritty, Chantelle; Lutje, Vittoria; Buckley, Brian; Soares-Weiser, Karla; Marshall, Rachel; Clarke, Mike; Horby, Peter (BMC Medicine, 2019)