The Prognostic Value of Red Blood Cell Distribution Width-to-Albumin Ratio (RAR) in Predicting Mortality and Severity in Acute Pancreatitis: A Systematic Review and Meta-Analysis.

Acute pancreatitis is a potentially life-threatening inflammatory condition with variable clinical presentations. Early risk stratification remains challenging despite existing scoring systems. The red blood cell distribution width-to-albumin ratio (RAR) has emerged as a potential prognostic biomarker in inflammatory conditions. This systematic review and meta-analysis aimed to evaluate the association between admission RAR and outcomes in acute pancreatitis. We conducted a comprehensive literature search and identified five retrospective studies meeting the inclusion criteria. Meta-analysis was performed to assess the relationship between RAR and mortality as well as disease severity in acute pancreatitis patients. Pooled analysis demonstrated that elevated RAR was significantly associated with increased mortality risk (risk ratio (RR): 2.11, 95% confidence interval (95% CI): 1.35-3.30) with moderate heterogeneity (I²: 46%). When comparing disease severity, mean RAR values were significantly lower in mild acute pancreatitis compared to severe cases (mean difference (MD): -1.78, 95% CI: -2.09 to -1.46), also with moderate heterogeneity (I²: 44%). This meta-analysis suggests that RAR, a simple and cost-effective biomarker available from routine blood tests, may serve as a valuable prognostic indicator for mortality and severity in acute pancreatitis. Despite having comparatively lower discriminative ability than conventional scoring systems, RAR offers advantages in terms of rapid assessment and cost efficiency. However, limitations include the small number of included studies, their retrospective nature, and heterogeneity in study settings. Further prospective studies are warranted to validate these findings.