Urinary Trypsinogen-2 Dipstick for Diagnosis of Post-ERCP Pancreatitis: A Cost-Benefit Analysis

Abstract

Purpose: Incidence of pancreatitis occurs in 1 to 10% of patients undergoing endoscopic retrograde cholangio-pancreatogaphy (ERCP). The diagnosis of post-ERCP pancreatitis is generally delayed due to lack of accurate tests; leading to unnecessary hospital stay and imaging studies. A few trials have demonstrated efficacy of Urinary Trypsinogen-2 Dipstick (UTP-2) in detection of pancreatitis as early as 4 hours post-ERCP. We used a cost-benefit approach to demonstrate its utility in detection of post-ERCP pancreatitis. Methods: Two separate meta-analyses of eight prospective trials using UTP-2 and serum amylase to diagnose post-ERCP pancreatitis was performed. Then a deterministic Monte Carlo decision model was constructed in the Treeage Software to simulate the progression of a hypothetical cohort of patients suffering from abdominal pain after ERCP. The cost was obtained from average estimated cost of treatment of mild pancreatitis in a hospitalized setting. The pretest probability for post-ERCP pancreatitis was assumed to be 7%. Cost benefit and sensitivity analysis was then conducted.Figure: [246]Results: Three trials were identified which used the UTP-2 for diagnosis of post-ERCP pancreatitis. All 3 were small single-center trials with sufficient heterogeneity and included 30 episodes of post-ERCP pancreatitis with total samples size of 287. Overall the pooled sensitivity, and specificity of the studies were 85% (95% CI: 0.673-0.953) and 94.4% (95% CI: 90.8%-96.8%). Similarly the pooled sensitivity, specificity of the studies for serum amylase was 79.3% (95% CI 72.4%-85.1%) and 86.2% (95% CI 85%-87.4%). Rolling back the decision tree revealed that the cost associated with UTP-2 strategy was lower than the amylase strategy due to improved accuracy of the test. Sensitivity analysis revealed that the optimal cost of urinary trypsinogen-2 dipstick test (<$270) should be less than four times the cost of serum amylase test to be the less costly strategy. The conclusions stayed robust on Monte Carlo simulation trials. Conclusion: There is a paucity of data regarding use of UTP-2 test in early diagnosis of post-ERCP pancreatitis. However, analysis of the available data clearly demonstrated that the using urinary trypsinogen-2 dipstick is less costly than using amylase for early diagnosis of post-ERCP pancreatitis.