To test the hypothesis that variables within the self system and the familial system significantly predicted sexual debut, all variables were entered into the equation simultaneously in the Cox Regression analysis. Exploratory analyses were conducted to assess the proportional hazards assumption. In addition to theoretical reasons for selecting 16 as the cutoff age for sexual debut (Rosenthal et al., 2001), it was determined that the proportional hazard model fit the data well for age of sexual debut occurring up to age 16. After this age, as it became increasingly common for a participant to have experienced first sexual intercourse, the relationship of the predictor variables to the hazard ratio was reduced. Earlier threshold ages of sexual debut were also explored; however, fewer participants had experienced sexual debut at younger ages thereby resulting in a loss of statistical power.
