title: Comparing cost-effectiveness between endoscopic ultrasound and endoscopic retrograde cholangiopancreatography in diagnosis of common bile duct stone in patients with predefined risks: A study from a developing country.
abstract: OBJECTIVE
  Endoscopic ultrasound (EUS) achieves results comparable to endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of common bile duct (CBD) stone, but studies from the western have shown EUS to be less expensive in patients with intermediate risk for CBD stones. The aim of this study was to compare the costs of EUS and ERCP in the diagnosis of CBD stones in a developing country.
  
  
  METHODS
  A prospective study was done with 141 patients with suspected CBD stones, categorized as having high or intermediate risk for CBD stone. All underwent EUS, and the high-risk patients had ERCP after the EUS. For intermediate-risk patients, an ERCP was done at the discretion of the attending physician. The CBD stone was confirmed by ERCP in patients who underwent both EUS and ERCP. Patients who received EUS only were followed up every 3 months for 1 year. The false negative rate in patients with EUS and ERCP was estimated in the clinical follow-up.
  
  
  RESULTS
  One hundred and forty-one patients (141: 83 females, 58 males) with a mean age ± standard deviation (SD) of 55.71 ±18.68 years were recruited. Ninety-four (94) patients underwent both EUS and ERCP. ERCP confirmed the diagnosis in 83 of 85 patients (97.6%) with CBD stone detected by EUS. Forty-seven (47) patients with a negative EUS and no ERCP done were symptom-free during the follow-up. The overall sensitivity, specificity, positive predictive value, and negative predictive value of EUS were 97.6%, 80%, 97.6%, and 80% respectively. An EUS-based strategy for high-risk patients was 15% more expensive than an ERCP-based strategy, but the EUS-based strategy reduced the cost to 37.78% less than the ERCP-based strategy in intermediate-risk patients. The EUS-based strategy was cost-saving when the CBD stone prevalence was less than 52.5%.
  
  
  CONCLUSIONS
  EUS is safer and less costly than ERCP for CBD stone diagnosis in patients with intermediate risk.
authors.affiliation: NKC Institute of Gastroenterology and Hepatology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkla, Thailand.
authors.forename: Nisa
authors.initials: N
authors.lastname: Netinatsunton
authors.affiliation: NKC Institute of Gastroenterology and Hepatology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkla, Thailand.
authors.forename: Siriboon
authors.initials: S
authors.lastname: Attasaranya
authors.affiliation: NKC Institute of Gastroenterology and Hepatology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkla, Thailand.
authors.forename: Jaksin
authors.initials: J
authors.lastname: Sottisuporn
authors.affiliation: NKC Institute of Gastroenterology and Hepatology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkla, Thailand.
authors.forename: Teepawit
authors.initials: T
authors.lastname: Witeerungrot
authors.affiliation: Divison of Gastroenterology, Department of Medicine, International Hospital, Bangmot, Chom Thon, Bangkok, Thailand.
authors.forename: Theeratus
authors.initials: T
authors.lastname: Jongboonyanuparp
authors.affiliation: NKC Institute of Gastroenterology and Hepatology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkla, Thailand.
authors.forename: Teerha
authors.initials: T
authors.lastname: Piratvisuth
authors.affiliation: NKC Institute of Gastroenterology and Hepatology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkla, Thailand.
authors.forename: Bancha
authors.initials: B
authors.lastname: Ovartlarnporn
keywords: Common bile duct (CBD) stone; cost; effectiveness; endoscopic retrograde cholangiopancreatography (ERCP)-based strategy; endoscopic ultrasound (EUS)-based strategy