Natural History Following the First Attack of Acute Pancreatitis

Abstract

OBJECTIVES: Data on natural history following a sentinel attack of acute pancreatitis (AP) are limited. The objective of this study was to determine the risk of recurrent AP (RAP) and subsequent chronic pancreatitis (CP) diagnosis after the first attack of AP. METHODS: Using the Pennsylvania Health Care Cost Containment Council (PHC4) data set, we identified all unique White and Black Allegheny County residents who received a first-time primary inpatient discharge diagnosis of AP from 1996 through 2005. AP etiology was determined using associated diagnoses codes. We also checked whether any of these patients were readmitted for AP and/or received inpatient CP diagnosis until third quarter of 2007. RESULTS: In all, 7,456 unique residents (mean age 58±20 years, 45% male, 80% White) with incident AP admission were identified. Common etiologies included biliary (28%), alcohol (19%), and idiopathic (36%). Compared with other causes, alcoholic AP patients were significantly younger and more likely to be male and Black. Among survivors (98.1%) and those without pancreatic cancer, follow-up (median 40 months, interquartile range 18, 69) was available for 84% of patients. Readmission for primary or any AP was recorded for 22 and 29%; subsequent primary or any CP diagnosis was assigned to 6 and 12.8%, respectively. Significant independent predictors for RAP were alcohol etiology and tobacco abuse and for CP were RAP and tobacco abuse. RAP risk in biliary AP increased with the duration between AP and cholecystectomy. CONCLUSIONS: Readmissions following a sentinel attack of AP are common. Progression to CP is infrequent and usually occurs in the setting of RAP, alcohol, and smoking. Cholectstectomy should be considered as soon as feasible after an attack of biliary AP. Natural history of CP may be altered through early behavioral intervention.