Background: The paper discusses the non-invasive (tubeless) pancreatic function tests used to diagnose exocrine pancreatic insufficiency (EI). Studies evaluating the diagnostic validity of these tests are integrated into a meta-analysis, provided that they comply with the following criteria: The sensitivity (Ss) of a test has to be calculated by comparing it with an invasive function test which is accepted as the gold standard of pancreatic function diagnostics. Furthermore, the test must differentiate between slight (sl), moderate (md) and severe (sv) EI. For assessment of the specificity (Sp), the control group should not contain healthy persons but rather patients with other gastrointestinal diseases and a normal pancreatic function. In the statistical evaluation, each study was weighted according to the number of persons included.
Results: Tests (n = sum of persons included in all analysed studies): Fecal chymotrypsin: Ss (n = 169) 54 % (sl EI), 53 % (md EI), 89 % (sv EI), Sp (n = 202) 74 %. NBT-PABA test: Ss (n = 394) 49 % (sl EI), 64 % (md EI), 72 % (sv EI), Sp (n = 218) 83 %. Pancreolauryl test: Ss (n = 320) 63 % (sl EI), 76 % (md EI), 94 % (sv EI), Sp (n = 171) 85 %. Fecal elastase-1: Ss (n = 307) 54 % (sl EI), 75 % (md EI), 95 % (sv EI), Sp (n = 347) 79 %. Additional tests discussed but not included in the meta-analysis were fecal fat, (13)C breath tests, amino acid consumption test, serum tests.
Conclusion: None of the non-invasive pancreatic function tests is sensitive enough to diagnose reliably a slight to moderate exocrine pancreatic insufficiency.