Distributions of the incidences of suicidal ideation and suicide attempts varied by gender; therefore, data obtained from males and females were analyzed separately in all analyses. Chi-square tests were used to examine the differences between males and females in the lifetime prevalence of alcohol drinking, cigarette smoking, and sexual intercourse (Table 1). Distribution of all variables was also presented by gender (Table 2). Descriptive analyses were performed using a chi-square test and univariate logistic regression analysis to investigate the associations between early initiation of problem behaviors and suicidal behaviors (Table 3). To avoid any possible confounding effects among our primary variables, multivariate logistic regression analyses were conducted and included all covariates (Table 4). Multivariate analyses were also performed to determine the effect of concurrent participation in these problem behaviors on each outcome (Table 5). The significance level was set at p < 0.05. All analyses were performed using SAS statistical software (version 9.1).
