COMPARISON OF THE BISAP SCORE WITH THE CONTRAST ENHANCED CT SEVERITY INDEX IN PREDICTING SEVERE ACUTE PANCREATITIS: A RETROSPECTIVE OBSERVATIONAL STUDY

Abstract

Background: Acute pancreatitis has a highly variable clinical course, ranging from mild self-limiting disease to severe pancreatitis complicated by organ failure and death. Early identification of patients likely to develop severe disease is essential to guide triage, resource allocation, and timely escalation of care. The Bedside Index for Severity in Acute Pancreatitis (BISAP) is a simple bedside clinical score, while the Contrast-Enhanced CT Severity Index (CTSI) is a radiological score based on pancreatic inflammation and necrosis. This study compared the diagnostic performance of BISAP and CTSI in predicting severe acute pancreatitis, using the Revised Atlanta Classification as the reference standard. Methods: This retrospective observational study was conducted at Saveetha Medical College and Hospital over a one year period. Records of 60 patients admitted with acute pancreatitis, aged 18-55 years (male:female ratio 3:1), were reviewed. Disease severity was classified using the Revised Atlanta Classification, and BISAP (cut-off >=3) and CTSI (cut-off >=7) scores were retrospectively calculated for each patient from admission clinical/laboratory data and contrast enhanced CT findings, respectively. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated for both scores against the Revised Atlanta Classification. Results: Of the 60 patients, 35 (58.3%) had severe acute pancreatitis and 25 (41.7%) had non-severe (mild/moderate) disease by Revised Atlanta Classification. BISAP demonstrated a sensitivity of 71.4%, specificity of 84.0%, PPV of 86.2%, NPV of 67.7%, and diagnostic accuracy of 76.7%. CTSI demonstrated a sensitivity of 82.9%, specificity of 88.0%, PPV of 90.6%, NPV of 78.6%, and diagnostic accuracy of 85.0%. CTSI numerically outperformed BISAP on every diagnostic parameter, although the difference in overall accuracy did not reach statistical significance in this cohort (chi square with Yates' correction = 0.86, p = 0.35). Conclusion: In this retrospective cohort, CTSI showed numerically higher sensitivity, specificity, and diagnostic accuracy than BISAP for predicting severe acute pancreatitis. However, BISAP is calculable at admission using only clinical and laboratory parameters, without the delay, cost, and radiation/contrast exposure associated with CT, and therefore retains practical value for early bedside risk stratification. Larger prospective studies are needed to confirm these findings and clarify the comparative and complementary roles of BISAP and CTSI.