Computed tomography scan imaging in diagnosing acute uncomplicated pancreatitis: Usefulness vs cost

Abstract

Background: Literature has suggested that imaging is over-utilized in the diagnosis of pancreatitis. If the diagnosis of acute pancreatitis (AP) is established with abdominal pain and increased serum amylase or lipase activity without systemic signs of severe disease, computed tomography (CT) imaging may not be necessary. We hypothesize that among patients with uncomplicated acute pancreatitis (AUP), there is a significant number of unwarranted CT imaging studies. This imposes increased expenditure and cost in our healthcare system and does not improve hospital stay or management of AUP.

Aim: To assess the overutilization and associated cost of CT imaging among patients meeting diagnostic criteria for AUP.

Methods: In this Institutional Review Board-approved retrospective, single-center study, we identified all adult patients admitted with AP from January 1, 2012 through October 1, 2017. Patients were identified via International Classification of Diseases (ICD-9) code for AP (577.0) and ICD-10 codes for different etiological AP (K85.9 unspecified, K85.0 idiopathic, K85.1 biliary, K85.2 alcohol-induced, K85.3 drug-induced, and K85.8 other). Diagnosis was confirmed by chart review using established non-imaging diagnostic criteria (presence of typical abdominal pain and elevated lipase or amylase greater than 3 times upper limit of normal). Ranson criteria and BISAP scores on presentation were calculated and patients that met scores less than or equal to 2 for both were included to suggest AUP. The utilization and cost of imaging in these patients were recorded.

Results: Between January 2012 and October 2017, 1305 patients presented to the emergency department with AP, and 405 patients (31%) met our inclusion criteria for AUP (201 males, 204 females; mean age 49 years, range 18-98). Of those, 210 patients (51.85%) underwent CT imaging. One patient (0.47%) had evidence of pancreatic necrosis, one patient had cyst formation (0.47%), and the remaining 208 patients (99.05%) had either normal CT scan imaging or findings consistent with mild AP without necrosis. The average cost of CT scan imaging was $4510 with a total cost of $947056. Median length of hospitalization stay was 3 d among both groups. Combining Ranson's Criteria and BISAP score identified AUP in our patient population with an accuracy of 99.5%.

Conclusion: CT imaging is unnecessary when AUP is diagnosed clinically and biochemically. Reducing overuse of diagnostic CT scans will decrease healthcare expenditure and radiation exposure to patients.

Keywords: Acute pancreatitis; Computed tomography imaging utilization; Diagnostic criteria; Emergency department; Healthcare expenditure; Quality improvement.