title: The role of antibiotic prophylaxis in routine endoscopic retrograde cholangiopancreatography investigations as assessed prospectively in a nationwide study cohort.
abstract: OBJECTIVE
  Risk factors for complications after endoscopic retrograde cholangiopancreatography (ERCP) with emphasis on the potential advantage of the use of prophylactic antibiotics were studied in a national population-based study cohort.
  
  
  METHODS
  All ERCP procedures registered in the Swedish Registry of Gallstone Surgery and ERCP (GallRiks) between May 2005 and June 2013 were analyzed. Patients with ongoing antibiotic treatment, incomplete registration or those who had not undergone an index ERCP were excluded. Risk factors for adverse events were analyzed.
  
  
  RESULTS
  Data from 47,950 ERCPs were collected, but after applying the exclusion criteria, 31,188 examinations were analyzed. In the group receiving prophylactic antibiotics, the postoperative adverse event rate was 11.6% compared with 14.2% in the group without antibiotics. The odds ratio (OR) for the risk of postoperative adverse events in patients receiving prophylactic antibiotics was 0.74 (95% confidence interval [CI]: 0.69-0.79). When analyzing a subgroup of 21,893 ERCPs for the three most common indications (common bile duct stones, malignancy, and obstructive jaundice), the beneficial effect of prophylactic antibiotics on adverse events remained (OR = 0.76; 95% CI: 0.70-0.82). Further, in the subgroup of patients with obstructive jaundice, the administration of prophylactic antibiotics had a beneficial effect on septic complications (OR = 0.76; 95% CI: 0.58-0.97).
  
  
  CONCLUSIONS
  The risk of adverse events after ERCP is reduced 26% if antibiotics are given prophylactically during ERCP investigations, as suggested by data gained from this national population-based study. However, in absolute terms, the reduction in adverse events by prophylactic antibiotics is modest (2.6%).
authors.affiliation: Department of Clinical Sciences, Intervention and Technology, CLINTEC, Karolinska Institutet , Stockholm , Sweden.
authors.forename: Greger
authors.initials: G
authors.lastname: Olsson
authors.forename: Urban
authors.initials: U
authors.lastname: Arnelo
authors.forename: Lars
authors.initials: L
authors.lastname: Lundell
authors.forename: Gunnar
authors.initials: G
authors.lastname: Persson
authors.forename: Björn
authors.initials: B
authors.lastname: Törnqvist
authors.forename: Lars
authors.initials: L
authors.lastname: Enochsson
mesh_terms: D000368:Aged; D019072:Antibiotic Prophylaxis / Q000706:statistics & numerical data*; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000009:adverse effects* / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D061646:Operative Time; D011183:Postoperative Complications / Q000517:prevention & control*; D012307:Risk Factors; D013548:Sweden
keywords: cholangitis; endoscopic retrograde cholangiopancreatography; postoperative adverse events; prophylactic antibiotics