Clinical usefulness of scoring systems to predict severe acute pancreatitis: A systematic review and meta‐analysis with pre and post‐test probability assessment

BACKGROUND: Scoring systems for severe acute pancreatitis (SAP) prediction should be used in conjunction with pre‐test probability to establish post‐test probability of SAP, but data of this kind are lacking. OBJECTIVE: To investigate the predictive value of commonly employed scoring systems and their usefulness in modifying the pre‐test probability of SAP. METHODS: Following PRISMA statement and MOOSE checklists after PROSPERO registration, PubMed was searched from inception until September 2022. Retrospective, prospective, cross‐sectional studies or clinical trials on patients with acute pancreatitis defined as Revised Atlanta Criteria, reporting rate of SAP and using at least one score among Bedside Index for Severity in Acute Pancreatitis (BISAP), Acute Physiology and Chronic Health Examination (APACHE)‐II, RANSON, and Systemic Inflammatory Response Syndrome (SIRS) with their sensitivity and specificity were included. Random effects model meta‐analyses were performed. Pre‐test probability and likelihood ratio (LR) were combined to estimate post‐test probability on Fagan nomograms. Pooled severity rate was used as pre‐test probability of SAP and pooled sensitivity and specificity to calculate LR and generate post‐test probability. A priori hypotheses for heterogeneity were developed and sensitivity analyses planned. RESULTS: 43 studies yielding 14,116 acute pancreatitis patients were included: 42 with BISAP, 30 with APACHE‐II, 27 with Ranson, 8 with SIRS. Pooled pre‐test probability of SAP ranged 16.6%–25.3%. The post‐test probability of SAP with positive/negative score was 47%/6% for BISAP, 43%/5% for APACHE‐II, 48%/5% for Ranson, 40%/12% for SIRS. In 18 studies comparing BISAP, APACHE‐II, and Ranson in 6740 patients with pooled pre‐test probability of SAP of 18.7%, post‐test probability when scores were positive was 48% for BISAP, 46% for APACHE‐II, 50% for Ranson. When scores were negative, post‐test probability dropped to 7% for BISAP, 6% for Ranson, 5% for APACHE‐II. Quality, design, and country of origin of the studies did not explain the observed high heterogeneity. CONCLUSIONS: The most commonly used scoring systems to predict SAP perform poorly and do not aid in decision‐making.