Is a 15-minute collection of duodenal secretions after secretin stimulation sufficient to diagnose chronic pancreatitis?

Background: Standard hormonal stimulation tests of pancreatic function use a 60- to 90-minute collection of pancreatic secretions. A shorter 15-minute collection time has been proposed to increase the feasibility of the secretin stimulation test. The accuracy of this brief collection period for the diagnosis of chronic pancreatitis has not been well defined. Methods: We retrospectively evaluated the accuracy of a 15-minute collection period by comparing the results of 633 complete standard secretin tests (60 minutes) to the result using only the first 15-minute collection of the same test. The gold standard used for the diagnosis of chronic pancreatitis was the final result of the complete 60- minute secretin stimulation test. Results: The specificity of the first 15-minute collection was 34.6% (95% CI, 30.03%-39.21%). The positive predictive value was 44.9% (95% CI, 40.5%-49.3%). The accuracy was 57.3% (95% CI, 53.01% 59.34%). Conclusions: Using only the first 15-minute collection period in a standard 60- minute secretin test is inaccurate in the diagnosis of chronic pancreatitis.