title: The Zelnorm epidemiologic study (ZEST): a cohort study evaluating incidence of abdominal and pelvic surgery related to tegaserod treatment.
abstract: BACKGROUND
  Pre-marketing clinical studies of tegaserod suggested an increased risk of abdominal surgery, particularly cholecystectomy. We sought to quantify the association between tegaserod use and the occurrence of abdominal or pelvic surgery, including cholecystectomy.
  
  
  METHODS
  This cohort study was conducted within an insured population. Tegaserod initiators and similar persons who did not initiate tegaserod were followed for up to six months for the occurrence of abdominal or pelvic surgery. Surgical procedures were identified from health insurance claims validated by review of medical records. The incidence of confirmed outcomes was compared using both as-matched and as-treated analyses.
  
  
  RESULTS
  Among 2,762 tegaserod initiators, there were 94 abdominal or pelvic surgeries (36 gallbladder): among 2,762 comparators there were 134 abdominal or pelvic surgeries (37 gallbladder) (hazard ratio HR] = 0.70, 95% confidence interval [C.I.] = 0.54-0.91 overall, HR = 0.98, 95% C.I. = 0.62-1.55 for gallbladder). Current tegaserod exposure compared to nonexposure was associated with a rate ratio [RR] of 0.68 (95% C.I. = 0.48-0.95) overall, while the RR was 0.99 (95% C.I. = 0.56-1.77) for gallbladder surgery.
  
  
  CONCLUSIONS
  In this study, tegaserod use was not found to increase the risk of abdominal or pelvic surgery nor the specific subset of gallbladder surgery.
authors.affiliation: Brigham & Women's Hospital and Harvard Medical School, Boston, MA, USA. jdseeger@partners.org.
authors.forename: John D
authors.initials: JD
authors.lastname: Seeger
authors.forename: Sherry
authors.initials: S
authors.lastname: Quinn
authors.forename: David L
authors.initials: DL
authors.lastname: Earnest
authors.forename: Anthony
authors.initials: A
authors.lastname: Lembo
authors.forename: Braden
authors.initials: B
authors.lastname: Kuo
authors.forename: Elena
authors.initials: E
authors.lastname: Rivero
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Walker
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002763:Cholecystectomy / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007211:Indoles / Q000009:adverse effects*; D007223:Infant; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000601:surgery*; D057216:Propensity Score; D017366:Serotonin Receptor Agonists / Q000009:adverse effects*; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D007211:Indoles; D017366:Serotonin Receptor Agonists; C105050:tegaserod