Data on each patient, which were collected by means of a review of endoscopy records, patient charts, and pathology reports, included age, sex, race, location at the time of endoscopy (inpatient vs outpatient), presence of comorbid illness, history of peptic ulcer disease, history of upper or lower gastrointestinal hemorrhage, presence of anemia, and use of alcohol, aspirin, NSAIDs, anticoagulants, or tobacco. Comorbid illness was defined as the presence of any of the following: cardiovascular disease (congestive heart failure, recurrent angina, or endocarditis), pulmonary disease (pneumonia, pulmonary embolus, or chronic obstructive pulmonary disease), liver disease (acute hepatitis, chronic hepatitis, or cirrhosis), renal disease (creatinine level >177 µmol/L [>2 mg/dL]), neurologic disease (meningitis or central nervous system disease with loss of independence), metastatic cancer, or the presence of a systemic bacterial or fungal infection. Anemia was defined as a hemoglobin level of less than 140 g/L in men or less than 120 g/L in women. Fecal occult blood testing was performed by testing 2 samples from each of 3 SPS or 1 specimen obtained during DRE using commercially available test kits (Hemoccult II; SmithKline Diagnostics Inc, San Jose, Calif) without rehydration. The presence of occult blood was identified when a positive test result was noted on at least 1 slide.