title: The influence of duration of follow-up on the association between alcohol and cause-specific mortality in a prospective cohort study.
abstract: OBJECTIVE
  To investigate whether duration of follow-up influences the association between alcohol and cause-specific mortality in a prospective cohort study with only baseline assessment of alcohol intake.
  
  
  METHODS
  In a cohort of 14,223 men and women participating in the first investigation of the Copenhagen City Heart Study between 1976 and 1978 and followed until 2001, we assessed whether the association between alcohol and mortality was modified by duration of follow-up. The 24 years of follow-up were divided into four intervals, and Cox survival analyses were conducted separately for these four succeeding 6-year periods of follow-up.
  
  
  RESULTS
  The authors found differences in the predictive values of alcohol and beverage-specific types of alcohol depending on duration of follow-up both in terms of all-cause mortality and death from coronary heart disease and cancer. The apparent protective effect of a moderate alcohol consumption on coronary heart disease attenuated during prolonged follow-up, whereas high alcohol consumption became associated with higher risk of death from cancer with longer follow-up.
  
  
  CONCLUSIONS
  This study accentuates the importance of taking duration of follow-up into consideration when interpreting risk estimates from prospective studies on the association between alcohol and mortality.
authors.affiliation: Centre for Alcohol Research, National Institute of Public Health, Copenhagen, Denmark. nrn@niph.dk
authors.forename: Naja Rod
authors.initials: NR
authors.lastname: Nielsen
authors.forename: Lau Caspar
authors.initials: LC
authors.lastname: Thygesen
authors.forename: Ditte
authors.initials: D
authors.lastname: Johansen
authors.forename: Gorm
authors.initials: G
authors.lastname: Jensen
authors.forename: Morten
authors.initials: M
authors.lastname: Grønbaek
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000453:epidemiology*; D001515:Beer; D015897:Comorbidity; D003327:Coronary Disease / Q000453:epidemiology* / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000401:mortality*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D013997:Time Factors; D014920:Wine