Comparative Analysis of the Modified Atlanta Classification and CT Severity Index in Assessing Acute Gallstone Pancreatitis: A Study at PIMS Hospital, Islamabad

Background: Acute gallstone pancreatitis (AGP) is a significant gastrointestinal emergency with variable degrees of severity. Exact classification is important for guiding clinical management and predicting patient outcomes. The Modified Atlanta Classification (MAC) and the Computed Tomography Severity Index (CTSI) are widely used for severity assessment, but their comparative effectiveness remains a subject of debate.Aim: Our Current research intended to assess the efficiency of the Modified Atlanta Classification and the Computed Tomography Severity Index in assessing disease severity and predicting clinical outcomes in patients with acute gallstone pancreatitis.Methods: A cross-sectional study was led at the Pakistan Institute of Medical Sciences (PIMS), Islamabad, from August 2024 to January 2025. A total of 130 patients diagnosed with acute gallstone pancreatitis were included. Severity classification was performed using both the Modified Atlanta Classification and the Computed Tomography Severity Index. Clinical outcomes, including length of hospital stay, need for intensive care unit (ICU) admission, complications, and mortality, were analyzed and compared between the two classification methods. Statistical analysis was conducted using SPSS, with p-values <0.05 considered significant.Results: The study included 130 patients diagnosed with AGP at PIMS Islamabad. The Modified Atlanta Classification categorized 42% of cases as mild, 36% as moderately severe, and 22% as severe, while the CTSI classified 38% as mild, 40% as moderate, and 22% as severe. The MAC showed a stronger correlation with ICU admissions (p < 0.05) and organ failure, whereas the CTSI was more predictive of local complications. The length of hospital stay was significantly longer in patients classified as severe by either system (p < 0.001). Both classification methods demonstrated high predictive accuracy, but the CTSI was slightly more effective in identifying patients requiring intensive care.Conclusion: Both the Modified Atlanta Classification and the Computed Tomography Severity Index were effective in assessing acute gallstone pancreatitis severity. The Modified Atlanta Classification showed superior predictive value for ICU admission and mortality, whereas the Computed Tomography Severity Index was more closely associated with local pancreatic complications. A combined approach may enhance the accuracy of severity assessment and patient management in acute gallstone pancreatitis.