METHODS: This retrospective study included adult CP patients evaluated with both 24-h fecal-fat and FE tests within a 3-month period. The objective was to evaluate the diagnostic performance of FE to diagnose steatorrhea and to evaluate the FE progression over 9-month period.
RESULTS: Among the 147 included patients, the frequency of steatorrhea (fecal fat >7 g/day) was 34%. The sensitivity, specificity, and negative likelihood ratio (LR) of FE was 90%, 28.9% and 0.35 at cut-off of <100 μg/g stool to diagnose steatorrhea; and 96%, 11.3% and 0.35 at cut-off of <200 μg/g stool, respectively. The optimal cut-off of FE was <20 on receiver operating characteristic curve (sensitivity 66%; specificity 69%; positive LR 2.14). There was no statistically significant variation in FE levels over 9 months interval among a hundred patients.
CONCLUSIONS: Compared to FE ≥ 200 μg/g stool, FE ≥ 100 can used to exclude steatorrhea (better specificity and negative LR). FE < 20 alone cannot replace fecal fat estimation to confirm steatorrhea but to be interpreted with clinical features. Repeat FE testing for exocrine insufficiency progression can be done at least a year later.