In public health efforts, knowledge about risk-groups is important for creating societal conditions to ensure good health on equal terms.
To investigate differences in lifestyle and perceived health among 15-year-old teenagers with experience of sexual intercourse (self-defined) and same-aged teenagers without experience of sexual intercourse.
A two-cluster questionnaire study among 15-year-old Swedish students (n = 2170) in 2009/10. Chi-squared test was used to identify differences between three groups: teenagers who had not had sexual intercourse; teenagers who had had sexual intercourse at age of 14 or younger; and teenagers who had had intercourse at an age of 15.
Thirty-two per cent (n = 334) of girls and 31% (n = 324) of boys had had sexual intercourse. Teenagers with experience of sexual intercourse at 15 years or younger used more tobacco, alcohol and illicit drugs than same-aged teenagers without intercourse experience did. Furthermore, teenagers with experience of intercourse, especially those with a debut at 14 year or younger, had less positive school experiences, more involvement in injuries and physical violence, were less (girls) and more (boys) physically active, and perceived a poorer health than teenagers without intercourse experience.
Sexual intercourse at the age of 15 or younger is an indicator for a hazardous lifestyle and problematic life situation.