Fecal immunochemical tests (FITs) measure the globin portion of human hemoglobin and have been validated for the use of colorectal cancer screening. FIT testing is associated with many false positive (type I errors) due to GI inflammation, certain medications and even some foods. Furthermore, studies show that FIT testing often has little to no impact on clinical decision making in the hospital setting. Many argue the test adds cost and risk without providing meaningful clinical value in the inpatient setting.
The Slicer-Dicer tool of the EPIC electronic medical record system was used to identify patients hospitalized at UC San Diego affiliated hospitals between January and July 2018 who had a FIT test ordered. The primary outcome was proportion of patients with positive FIT testing receiving endoscopy. Secondary outcomes included reason for ordering FIT testing, proportion of patients referred for endoscopy at discharge, proportion of patients completing endoscopy after outpatient referral, and proportion of patients diagnosed with colon cancer on outpatient colonoscopy. Patient excluded were those who died during admission.
During the 6 month study period, 140 inpatient FIT tests were ordered and 76 (54.3%) were positive. The majority of tests were ordered by the internal medicine service (Figure 1). Anemia was the leading indication for ordering the test (60% of all cases). 21% of the tests were ordered despite documented melena/hematochezia, and 70% of these tests were positive. Among the 76 patients with positive tests, 27 (36%) underwent inpatient EGD, 21 (28%) underwent inpatient colonoscopy, and 14 (18%) had both. Most patients with positive FIT testing did not receive an inpatient colonoscopy (72%, n = 55), and 42 (55.3%) did not receive any endoscopic testing. Of those 55 patients with positive FIT testing that did not receive inpatient colonoscopy, 26 (47%) did receive an outpatient GI referral, but only 8 (15%) received a colonoscopy within 6 months of discharge. No colon cancer was diagnosed in this small cohort. Among the 76 patients with positive inpatient FIT tests, 29 (38%) had neither GI referral nor endoscopy performed.
Inappropriate use of FIT testing was prevalent at our institution, with inadequate documented follow up of abnormal testing in over one third of patients. Inadequate follow up can potentially lead to missed diagnoses of colon cancer.