In this study, we first conducted bivariate analyses comparing the mean ages of initiation of drinking, age of onset of alcohol dependence, and the mean time in years from drinking initiation to development of alcohol dependence using a Wald test. Next, we examined the risk of alcohol initiation, alcohol dependence and the transition from initiation of alcohol use to onset of alcohol dependence separately using discrete time survival analyses. For the estimation of the cumulative probability of dependence upon alcohol, we set two time perspectives. According to the first perspective, time is measured chronologically in years since birth. In the second perspective, the time-scale is set as years since first alcohol use. In the survival models, the 3,455 alcohol abstainers were censored at their age at the time of the interview. Additionally there were 270 individuals who had consumed alcohol but had an unknown or missing age of onset and 37 individuals who met criteria for alcohol dependence but had an unknown or missing age of dependence. Their missing ages excluded them from the survival models.
