TY - STAND AU - C. Crooks AU - J. West AU - T. Card BT - Gastroenterology DO - 10.1053/j.gastro.2013.02.040 M1 - 7 PY - 2013 SP - 1384 EP - 93 T2 - Gastroenterology TI - Comorbidities affect risk of nonvariceal upper gastrointestinal bleeding VL - 144 SN - 0016-5085 ER -