Design and implementation of a web-based patient portal linked to an electronic health record designed to improve medication safety: the Patient Gateway medications module - Schnipper, JL; Gandhi, TK; Wald, JS; Grant, RW; Poon, EG; Volk, LA; Businger, A; Siteman, E; Buckel, L; Middleton, B (Inform Prim Care, 2008)