Evaluation of stool collections to measure efficacy of PERT in subjects with exocrine pancreatic insufficiency

J Pediatr Gastroenterol Nutr. 2011 Dec;53(6):634-40. doi: 10.1097/MPG.0b013e3182281c38.


Objective: The standard measure of pancreatic enzyme replacement therapy (PERT) efficacy in treating exocrine pancreatic insufficiency (EPI) is the coefficient of fat absorption (CFA). CFA measurement involves 72-hour stool collection, which presents a logistical challenge because, although the test may be performed on an outpatient basis in clinical practice, hospitalization is needed if assurance of complete collection and 100% compliance is required, for example, in controlled situations such as clinical trials. Our aim was to investigate sparse stool sample collection as an alternative to complete 72-hour collection for measurement of stool fat in subjects with EPI.

Subjects and methods: Prospective data analysis from a previously published, double-blind, randomized, placebo-controlled, 2-period crossover trial in subjects ages 7 to 11 years with EPI caused by cystic fibrosis. Percentage fat (PF) data from sparse stool samples were compared with 72-hour CFA values as a dichotomous variable (<80%, ≥80%), with evaluation of sensitivity, specificity, and positive predictive value. Area under the curve values were obtained from receiver operating characteristic plots of sensitivity versus 1-specificity.

Results: Twelve subjects provided samples for this analysis. Multiple-sample PF values ≤30% were greatly predictive for CFA values ≥80%, as shown by positive predictive value, sensitivity, and specificity values ≥0.89, with high accuracy (AUCs ≥0.93).

Conclusions: Sparse stool sampling for PF analysis appears to be a valid, practical alternative to 72-hour CFA determination and has potential as a screening tool in clinical practice to identify both suboptimal dosing in subjects with EPI receiving PERT and substantial fat malabsorption in subjects not receiving PERT.

Trial registration: ClinicalTrials.gov NCT00690820.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child
  • Cross-Over Studies
  • Cystic Fibrosis / complications
  • Cystic Fibrosis / physiopathology
  • Double-Blind Method
  • Enzyme Replacement Therapy / methods*
  • Exocrine Pancreatic Insufficiency / diagnosis*
  • Exocrine Pancreatic Insufficiency / etiology
  • Fats / analysis
  • Feces*
  • Female
  • Humans
  • Intestinal Absorption / drug effects
  • Male
  • Pancreas / drug effects
  • Pancreas / physiopathology*
  • Pancrelipase / administration & dosage
  • Predictive Value of Tests
  • Prospective Studies
  • Randomized Controlled Trials as Topic
  • Sensitivity and Specificity


  • Fats
  • Pancrelipase

Associated data

  • ClinicalTrials.gov/NCT00690820