Positive predictive value of acute and chronic pancreatitis diagnoses in the Danish National Patient Registry: A validation study.

Aims: To examine the validity of the diagnoses of acute and chronic pancreatitis registered in the Danish National Patient Registry.
Methods: We identified all patients in the Danish National Patient Registry admitted to two Danish hospitals with acute or chronic pancreatitis from 1996 to 2013. From this population, we randomly sampled 100 patients with acute pancreatitis and 100 patients with chronic pancreatitis. For each cohort, we computed the positive predictive values and associated 95% confidence intervals (CIs) for the discharge diagnosis of acute or chronic pancreatitis using medical records as the gold standard.
Results: We identified 2617 patients with acute pancreatitis and 1284 patients with chronic pancreatitis discharged from either of the two hospitals during the study period. Of these, 776 (19.9%) had a diagnosis of both acute and chronic pancreatitis and are thus present in both cohorts. From the 200 sampled patients, a total of 138 (69.0%) medical records were available for review. The positive predictive value for a diagnosis of acute pancreatitis in the Danish National Patient Registry was 97.3% (95% CI 90.5-99.2%) and for chronic pancreatitis 83.1% (95% CI 72.2-90.3%). Conclusions: The validity of diagnoses of acute and chronic pancreatitis registered in the Danish National Patient Registry since 1996 is generally high.