Morbid obesity but not obesity is associated with increased mortality in patients undergoing endoscopic retrograde cholangiopancreatography: A national cohort study

BACKGROUND: The relationship between body weight and outcomes of endoscopic retrograde cholangiopancreatography (ERCP) is unclear. OBJECTIVES: This study aimed to investigate the impact of obesity and morbid obesity on mortality and ERCP‐related complications in patients who underwent ERCP. METHODS: We conducted a US population‐based retrospective cohort study using the Nationwide Readmissions Databases (2013–2014). A total of 159,264 eligible patients who underwent ERCP were identified, of which 137,158 (86.12%) were normal weight, 12,522 (7.86%) were obese, and 9584 (6.02%) were morbidly obese. The primary outcome was in‐hospital mortality. The secondary outcomes were the length of stay, total cost, and ERCP‐related complications. Multivariate analysis and propensity score (PS) matching analysis were performed. The analysis was repeated in a restricted cohort to eliminate confounders. RESULTS: Patients with morbid obesity, as compared to normal‐weight patients, were associated with a significantly higher in‐hospital mortality (hazard ratio [HR]: 5.54; 95% confidence interval [CI]: 1.23–25.04). Obese patients were not associated with significantly different mortality comparing to normal weight (HR: 1.00; 95% CI: 0.14–7.12). Patients with morbid obesity were also found to have an increased length of hospital stay and total cost. The rate of ERCP‐related complications was comparable among the three groups except for a higher cholecystitis rate after ERCP in obese patients. CONCLUSIONS: Morbid obesity but not obesity was associated with increased mortality, length of stay, and total cost in patients undergoing ERCP.