Classification of a Cohort of Acute Pancreatitis Patients
Objectives Atlanta classification (Atlanta 1992) of acute pancreatitis (AP) has several limitations. Two new classification systems were recently proposed: the Atlanta reclassification (Atlanta 2012) and the determinant-based classification (DBC). The aim of our study was to: (i) determine the association between different severity categories and clinical outcomes and (ii) perform a head-to-head comparison between Atlanta 1992, Atlanta 2012, and DBC in predicting these clinical outcomes.
Methods A total of 256 prospectively enrolled patients were assigned a severity category for all three classifications. Five clinical outcomes were evaluated: mortality, intensive care unit (ICU) admission and length of stay (LOS), need for interventions, and hospital LOS. Pairwise testing between severity grades within a classification system was performed using Fisher's exact and Kruskal–Wallis tests. Predictive accuracies were evaluated using area under the ROC curve (AUC) and Somer's D co-efficient.
Resulst Overall, higher grades of severity were associated with worse clinical outcomes for all three classification systems. Atlanta 2012 and DBC performed better than Atlanta 1992 and were comparable in predicting mortality (AUC 0.89 for both vs. 0.76, P<0.001), ICU admission (AUC 0.91 for both vs. 0.80, P<0.001), and ICU LOS (Somer's D 0.21 and 0.28 vs. 0.07, P<0.05). DBC performed better in predicting need for interventions (AUC 0.93 vs. 0.85, P<0.001), whereas Atlanta 2012 performed better in predicting hospital LOS (Somer's D 0.43 vs. 0.37, P=0.04).
Conclusions Atlanta 2012 and DBC severity categories accurately reflected clinical outcomes in our cohort and were superior to Atlanta 1992. These novel classification systems can guide the selection of homogeneous patient populations for clinical research and provide an accurate spectrum of disease severity categories in the clinical setting.
Acute pancreatitis (AP) is an inflammatory disease with a highly variable clinical course. This disease is currently the leading cause of gastrointestinal-related hospital admissions in the United States and continues to rise in incidence. Most patients (approximately 80%) with AP develop a mild course that results in a short, uncomplicated hospitalization. The remaining 20% develop a complicated clinical course that requires prolonged hospitalization, intensive care, invasive interventions, and results in significant mortality.
The most widely accepted classification system for severity in AP, the Atlanta classification, was reported in 1992. Atlanta 1992 divides AP into two groups: mild and severe. Severe disease is defined by the presence of organ failure (OF), local pancreatic complications on imaging (acute fluid collection, pancreatic necrosis (PNec), pseudocyst and pancreatic abscess), and/or poor prognostic scores (Ranson's ≥3 and/or APACHE-II≥8). Atlanta 1992 has offered a universally applicable classification system that successfully served clinical studies and aided in the comparison of data from different centers for over 20 years.
Based on advancements in the understanding of the pathophysiology and natural history of AP and improvements in diagnostic and prognostic tools, most pancreatologists recognize the necessity for revising the above classification system. More specifically, recent studies have highlighted that the presence of persistent OF lasting for ≥48 h, infected pancreatic necrosis (Inf PNec), and the combination of OF and Inf Pnec result in worse outcomes and higher mortality in patients within the "severe" category. Recently, two new classification systems for AP severity have been proposed. Both systems were led by international groups of experts that utilized a web-based consensus-building approach.
The revision of the Atlanta classification (Atlanta 2012) divides AP severity into three groups: mild, moderate, and severe. The newly introduced moderate category includes a mixed population of patients: those with transient OF (OF lasting <48 h), patients with deterioration in pre-existing comorbidities, as well as patients with local complications on imaging including acute peripancreatic fluid collections, pseudocysts, acute necrotic collections, and walled-off necrosis. The determinant-based classification (DBC) of AP severity introduces four groups of disease severity: mild, moderate, severe, and critical. Severity stratification is based on OF (transient vs. persistent) and PNec or peripancreatic necrosis (peri)PNec) (sterile vs. infected). The moderate DBC category is characterized by the presence of transient OF and/or sterile (peri)PNec. The newly introduced critical group includes patients with persistent OF and Inf (peri)PNec (Table 1).
These two novel classification systems and their categories were mainly derived from retrospective studies and expert opinion. The aim of this study is to apply the above severity classification systems on a prospectively enrolled, thoroughly phenotyped, cohort of patients with AP to: (i) determine the association of these novel classification systems with important clinical outcomes and (ii) perform a head-to-head comparison between Atlanta 1992, Atlanta 2012, and DBC with respect to these clinical outcomes.
Abstract and Introduction
Abstract
Objectives Atlanta classification (Atlanta 1992) of acute pancreatitis (AP) has several limitations. Two new classification systems were recently proposed: the Atlanta reclassification (Atlanta 2012) and the determinant-based classification (DBC). The aim of our study was to: (i) determine the association between different severity categories and clinical outcomes and (ii) perform a head-to-head comparison between Atlanta 1992, Atlanta 2012, and DBC in predicting these clinical outcomes.
Methods A total of 256 prospectively enrolled patients were assigned a severity category for all three classifications. Five clinical outcomes were evaluated: mortality, intensive care unit (ICU) admission and length of stay (LOS), need for interventions, and hospital LOS. Pairwise testing between severity grades within a classification system was performed using Fisher's exact and Kruskal–Wallis tests. Predictive accuracies were evaluated using area under the ROC curve (AUC) and Somer's D co-efficient.
Resulst Overall, higher grades of severity were associated with worse clinical outcomes for all three classification systems. Atlanta 2012 and DBC performed better than Atlanta 1992 and were comparable in predicting mortality (AUC 0.89 for both vs. 0.76, P<0.001), ICU admission (AUC 0.91 for both vs. 0.80, P<0.001), and ICU LOS (Somer's D 0.21 and 0.28 vs. 0.07, P<0.05). DBC performed better in predicting need for interventions (AUC 0.93 vs. 0.85, P<0.001), whereas Atlanta 2012 performed better in predicting hospital LOS (Somer's D 0.43 vs. 0.37, P=0.04).
Conclusions Atlanta 2012 and DBC severity categories accurately reflected clinical outcomes in our cohort and were superior to Atlanta 1992. These novel classification systems can guide the selection of homogeneous patient populations for clinical research and provide an accurate spectrum of disease severity categories in the clinical setting.
Introduction
Acute pancreatitis (AP) is an inflammatory disease with a highly variable clinical course. This disease is currently the leading cause of gastrointestinal-related hospital admissions in the United States and continues to rise in incidence. Most patients (approximately 80%) with AP develop a mild course that results in a short, uncomplicated hospitalization. The remaining 20% develop a complicated clinical course that requires prolonged hospitalization, intensive care, invasive interventions, and results in significant mortality.
The most widely accepted classification system for severity in AP, the Atlanta classification, was reported in 1992. Atlanta 1992 divides AP into two groups: mild and severe. Severe disease is defined by the presence of organ failure (OF), local pancreatic complications on imaging (acute fluid collection, pancreatic necrosis (PNec), pseudocyst and pancreatic abscess), and/or poor prognostic scores (Ranson's ≥3 and/or APACHE-II≥8). Atlanta 1992 has offered a universally applicable classification system that successfully served clinical studies and aided in the comparison of data from different centers for over 20 years.
Based on advancements in the understanding of the pathophysiology and natural history of AP and improvements in diagnostic and prognostic tools, most pancreatologists recognize the necessity for revising the above classification system. More specifically, recent studies have highlighted that the presence of persistent OF lasting for ≥48 h, infected pancreatic necrosis (Inf PNec), and the combination of OF and Inf Pnec result in worse outcomes and higher mortality in patients within the "severe" category. Recently, two new classification systems for AP severity have been proposed. Both systems were led by international groups of experts that utilized a web-based consensus-building approach.
The revision of the Atlanta classification (Atlanta 2012) divides AP severity into three groups: mild, moderate, and severe. The newly introduced moderate category includes a mixed population of patients: those with transient OF (OF lasting <48 h), patients with deterioration in pre-existing comorbidities, as well as patients with local complications on imaging including acute peripancreatic fluid collections, pseudocysts, acute necrotic collections, and walled-off necrosis. The determinant-based classification (DBC) of AP severity introduces four groups of disease severity: mild, moderate, severe, and critical. Severity stratification is based on OF (transient vs. persistent) and PNec or peripancreatic necrosis (peri)PNec) (sterile vs. infected). The moderate DBC category is characterized by the presence of transient OF and/or sterile (peri)PNec. The newly introduced critical group includes patients with persistent OF and Inf (peri)PNec (Table 1).
These two novel classification systems and their categories were mainly derived from retrospective studies and expert opinion. The aim of this study is to apply the above severity classification systems on a prospectively enrolled, thoroughly phenotyped, cohort of patients with AP to: (i) determine the association of these novel classification systems with important clinical outcomes and (ii) perform a head-to-head comparison between Atlanta 1992, Atlanta 2012, and DBC with respect to these clinical outcomes.
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