Pancreatic function testing: serum PABA measurement is a reliable and accurate measurement of exocrine function.

A comparison between the NBT-PABA/14C-PABA test (NBT-PABA, n-benzoyl-tyrosyl para-aminobenzoic acid) using the PABA excretion index (PEI) and serum PABA estimation at 90 minutes has been made in 42 consecutive subjects attending for investigation of possible pancreatic disease to a District General Hospital (DGH). The PEI was unobtainable or incorrect on 38% of occasions compared with 9% for the serum test. Sensitivity, specificity, and efficiency for the PEI (n = 33 valid results) were 71%, 88%, and 79% respectively and for the serum PABA (n = 41 valid results), 95%, 90%, and 93% respectively. These results confirm that measurement of serum PABA is a simpler, more reliable, and a more accurate method of assessing pancreatic function.