title: Gender differences in remission of esophageal intestinal metaplasia after radiofrequency ablation.
abstract: OBJECTIVE
  Few studies have assessed the effect of gender on remission rates after radiofrequency ablation (RFA) of Barrett's esophagus (BE). We aim to assess the effect of gender on the time to achieve complete remission of intestinal metaplasia (CRIM) among patients with BE, who underwent RFA.
  
  
  METHODS
  This was a retrospective, observational study using a large RFA database in a tertiary referral center. The primary outcome was time to CRIM compared between males and females. Covariates included age, race, smoking history, use of endoscopic mucosal resection (EMR), histology before RFA, and the number of RFA sessions. Time to CRIM (in months) was calculated using the Kaplan-Meier method and compared using the log-rank test. Multivariable Cox-proportional hazard models were used to assess for any association between time to CRIM and gender.
  
  
  RESULTS
  Two hundred and fifty-seven patients, 11% (n=23) female, underwent RFA for BE between May 2005 and June 2012. Males and females were similar in mean age, race, smoking history, median BE length, history of EMR, and baseline histology. Median time to CRIM for females was longer than males (24 months (95% confidence interval (CI): 10.3-60.2) vs. 11.7 months (95% CI: 10-15), P=0.03). Using Cox-regression analysis, controlling for age, use of EMR, BE segment length, and the number of RFA sessions, female gender was associated with a 55% decrease in the rate of CRIM compared with that in males (hazard ratio=0.45 (95% CI: 0.25-0.82), P=0.009).
  
  
  CONCLUSIONS
  Females take longer time to achieve CRIM when treated with RFA when compared with males of similar age and BE length.
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Jacksonville, Florida, USA.
authors.forename: Bashar
authors.initials: B
authors.lastname: Qumseya
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Jacksonville, Florida, USA.
authors.forename: Waseem
authors.initials: W
authors.lastname: David
authors.affiliation: Harvard School of Public Health and the Center for Surgery and Public Health (Brigham and Women's Hospital), Boston, Massachusetts, USA.
authors.forename: Marta
authors.initials: M
authors.lastname: McCrum
authors.affiliation: Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts,USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Jacksonville, Florida, USA.
authors.forename: Massimo
authors.initials: M
authors.lastname: Raimondo
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Jacksonville, Florida, USA.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Woodward
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Jacksonville, Florida, USA.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Wallace
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Jacksonville, Florida, USA.
authors.forename: Herbert C
authors.initials: HC
authors.lastname: Wolfsen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001471:Barrett Esophagus / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D004947:Esophagus / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D016016:Proportional Hazards Models; D012074:Remission Induction; D012189:Retrospective Studies; D012737:Sex Factors; D016019:Survival Analysis; D016896:Treatment Outcome