LFT Ordering Behavior PayamParvinchiha DSR 2
Guidelines • No guidelines for ordering of LFT • Should not be a screening test for liver disease • population-based survey in the United States conducted between 1999 and 2002 estimated that an abnormal ALT was present in 8.9 percent of respondents • ALT level correlates with body mass index (BMI) and waist circumference, and the BMI of Americans has increased significantly over time • Am J Gastroenterol. 2006;101(1):76.
Abnormal serum aminotransferase levels (ALT >2.25 SD above normal; >55 int. unit/L) were detected in 99 of 19,877 (0.5 percent) Air Force recruits beginning basic training . Of these, a cause was found in only 12 (including chronic hepatitis B and C, autoimmune hepatitis, and cholelithiasis). No specific diagnosis was established in the remaining 87 patients. • Dig Dis Sci. 1993;38(12):2145.
Most likely Dx • Another study focused on 81 of 1124 patients who were referred for abnormal serum aminotransferase levels in whom a diagnosis could not be inferred noninvasively . A liver biopsy revealed steatosis or steatohepatitis in the majority of patients (84 percent); six patients had fibrosis or cirrhosis, and eight had normal histologic findings. • Am J Gastroenterol. 1999;94(10):3010.
Fluctuations • Individual patients can have baseline fluctuation in serum aminotransferase levels. In a large, cross-sectional population-based study, more than 30 percent of adults with abnormal LFTS were reclassified as being normal upon retesting . • Ann Intern Med. 2008;148(5):348.
False positive • Normal reference values-arbitrarily determined to be 2 SD above the mean • 5 percent of healthy individuals who have a single screening test will have an abnormal result (2.5 percent will have an abnormally high result). As more tests are ordered, the likelihood of a false positive test increases; a screening panel containing 20 independent tests in a patient with no disease will yield at least one abnormal result 64 percent of the time
Cost of LFT • $25-$35 • Hepatitis Panel: $125 • RUQ Ultrasound: $125
Cross sectional Analysis • All patients on Ward Teams A/B on 3/25 • Admission Days, LFT on admission, # of LFT total, Hx of Liver Dx, Indication for LFT charted, New Abnormalities found, further w/u ordered
23 Patients • Avg LOS: 6.5 days • #LFT/Admission: 4.7 • #LFT/Day of admission: .8 • LFT on admission: 18/23 • Hx Liver Dx: 4/23 • Indications: 5/23 • New Abn: 14/23 • Further w/u: 6
If $25 / LFT then $20 spent / patient/day on LFT given this sample • $120 per admission on LFT’s • Most patient’s w/o indication for LFT’s • Minimal further w/u done in this population of ts