Developing a data infrastructure for a learning health system: the PORTAL network.
McGlynn EA, Lieu TA, Durham ML, Bauck A, Laws R, Go AS, Chen J, Feigelson HS, Corley DA, Young DR, Nelson AF, Davidson AJ, Morales LS, Kahn MG. Developing a data infrastructure for a learning health system: the PORTAL network. J Am Med Inform Assoc. 2014 Jul-Aug; 21(4):596-601.