title: Betel quid use and mortality in Bangladesh: a cohort study.
abstract: OBJECTIVE
  To evaluate the potential effects of betel quid chewing on mortality. (A quid consists of betel nut, wrapped in betel leaves; tobacco is added to the quid by some users).
  
  
  METHODS
  Prospective data were available on 20 033 individuals aged 18-75 years, living in Araihazar, Bangladesh. Demographic and exposure data were collected at baseline using a standardized questionnaire. Cause of death was defined by verbal autopsy questionnaires administered to next of kin. We estimated hazard ratios (HR) and their 95% confidence intervals (CI) for associations between betel use and mortality from all causes and from specific causes, using Cox proportional hazards models. We adjusted for age, sex, body mass index, educational attainment and tobacco smoking history.
  
  
  RESULTS
  There were 1072 deaths during an average of 10 years of follow-up. Participants who had ever used betel were significantly more likely to die from all causes (HR: 1.26; 95% CI: 1.09-1.44) and cancer (HR: 1.55; 95% CI: 1.09-2.22); but not cardiovascular disease (HR: 1.16; 95% CI: 0.93-1.43). These findings were robust to adjustment for potential confounders. There was a dose-response relationship between mortality from all causes and both the duration and the intensity of betel use. The population attributable fraction for betel use was 14.1% for deaths from all causes and 24.2% for cancer.
  
  
  CONCLUSIONS
  Betel quid use was associated with mortality from all causes and from cancer in this cohort.
authors.affiliation: Department of Population Health, New York University School of Medicine, 650 First Avenue, New York, NY 10016, United States of America (USA).
authors.forename: Fen
authors.initials: F
authors.lastname: Wu
authors.affiliation: Department of Environmental Health Sciences, Columbia University, New York, USA .
authors.forename: Faruque
authors.initials: F
authors.lastname: Parvez
authors.affiliation: U-Chicago Research Bangladesh Ltd., Dhaka, Bangladesh .
authors.forename: Tariqul
authors.initials: T
authors.lastname: Islam
authors.affiliation: U-Chicago Research Bangladesh Ltd., Dhaka, Bangladesh .
authors.forename: Alauddin
authors.initials: A
authors.lastname: Ahmed
authors.affiliation: U-Chicago Research Bangladesh Ltd., Dhaka, Bangladesh .
authors.forename: Muhammad
authors.initials: M
authors.lastname: Rakibuz-Zaman
authors.affiliation: U-Chicago Research Bangladesh Ltd., Dhaka, Bangladesh .
authors.forename: Rabiul
authors.initials: R
authors.lastname: Hasan
authors.affiliation: Department of Health Studies, University of Chicago, Chicago, USA .
authors.forename: Maria
authors.initials: M
authors.lastname: Argos
authors.affiliation: Department of Environmental Health Sciences, Columbia University, New York, USA .
authors.forename: Diane
authors.initials: D
authors.lastname: Levy
authors.affiliation: U-Chicago Research Bangladesh Ltd., Dhaka, Bangladesh .
authors.forename: Golam
authors.initials: G
authors.lastname: Sarwar
authors.affiliation: Department of Health Studies, University of Chicago, Chicago, USA .
authors.forename: Habibul
authors.initials: H
authors.lastname: Ahsan
authors.affiliation: Department of Population Health, New York University School of Medicine, 650 First Avenue, New York, NY 10016, United States of America (USA).
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen