The reporting of observational studies of drug effectiveness and safety: recommendations to extend existing guidelines

Cragg JJ, Azoulay L, Collins G, Vera MD, Etminan M, Lalji F, Gershon A, Guyatt G, Harrison M, Jutzeler C, Kassam R, Kendzerska T, Lynd L, Mansournia MA, Sadatsafavi M, Tong B, Warner F, Tremlett H