title: Evaluation of stool collections to measure efficacy of PERT in subjects with exocrine pancreatic insufficiency.
abstract: 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.
  
  
  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.
authors.affiliation: Abbott Products Inc, Marietta, GA, USA.
authors.forename: Steve
authors.initials: S
authors.lastname: Caras
authors.forename: David
authors.initials: D
authors.lastname: Boyd
authors.forename: Lisa
authors.initials: L
authors.lastname: Zipfel
authors.forename: Suntje
authors.initials: S
authors.lastname: Sander-Struckmeier
mesh_terms: D002648:Child; D018592:Cross-Over Studies; D003550:Cystic Fibrosis / Q000150:complications / Q000503:physiopathology; D004311:Double-Blind Method; D056947:Enzyme Replacement Therapy / Q000379:methods*; D010188:Exocrine Pancreatic Insufficiency / Q000175:diagnosis* / Q000209:etiology; D005223:Fats / Q000032:analysis; D005243:Feces; D005260:Female; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects; D008297:Male; D010179:Pancreas / Q000187:drug effects / Q000503:physiopathology*; D020799:Pancrelipase / Q000008:administration & dosage; D011237:Predictive Value of Tests; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D012680:Sensitivity and Specificity
chemical_list: D005223:Fats; D020799:Pancrelipase