Living systematic review: 1. Introduction-the why, what, when, and how

- Elliott, Julian H.; Synnot, Anneliese; Tovey, David; Shemilt, Ian; Thomas, James; Living Systematic Review Network,; Agoritsas, Thomas; Hilton, John; Perron, Caroline; Akl, Elie; Hodder, Rebecca; Pestridge, Charlotte; Turner, Tari; Wolfenden, Luke; Simmonds, Mark; Akl, Elie A.; McDonald, Steve; Salanti, Georgia; Meerpohl, Joerg; MacLehose, Harriet; Hilton, John