Automated identification of postoperative complications within an electronic medical record using natural language processing - Murff, HJ; FitzHenry, F; Matheny, ME; Gentry, N; Kotter, KL; Crimin, K; Dittus, RS; Rosen, AK; Elkin, PL; Brown, SH; Speroff, T (Jama, 2011)