INDIANAPOLIS — Female adolescents at high risk for acquiring sexually transmitted infections may not respond well to counseling and prevention efforts that focus on the fear of becoming infected, according to a study by researchers at Indiana University in Indianapolis.
Instead, programs and physicians may need to tailor their pregnancy and sexually transmitted infection (STI) counseling to recent patterns of sexual behavior, said Dr. Mary A. Ott of the university's section of adolescent medicine.
“Physicians and other counselors should be aware that fear related to being infected influences sexual behavior only in the short term, and therefore should focus on interpersonal and relationship factors to influence long-term decisions about sex and abstinence,” Dr. Ott said at the annual meeting of the Midwest Society for Pediatric Research.
This urban study of 378 high-risk females aged 14–18 years indicated that the decision to have sex after a period of abstinence was strongly influenced by the relationship between the girl and the male she was involved with, as well as by sexual interest and mood, Dr. Ott explained. This challenges the notion that adolescent sex is largely casual and lacking in personal commitment and caring.
The cohort completed quarterly face-to-face interviews and two 3-month daily diary collections per year, and were followed up for a maximum of 4.5 years.
Periods of abstinence were defined as consecutive days of no vaginal sex as recorded in the daily diary. At the time of the study, 9% of the girls had an active STI, either Chlamydia trachomatis, Neisseria gonorrhea, or Trichomonas vaginalis.
Frailty models were used to estimate the effects of intrapersonal and interpersonal factors, as well as the effect of STI diagnosis, on the time to ending a period of abstinence. A frailty model is an adaptation of a proportional hazards model that controls for multiple observations from a single participant.
The study cohort had more than 6,000 periods of abstinence, of which 55% ended in sex. The median length of abstinence was 10 days, and the mean length was 39 days. “Each year increase in a participant's age increased the hazard of ending an abstinence period with sex by 22%,” Dr. Ott said.
“For interpersonal influences, each unit increase in positive mood increased the hazard by 2%, each unit increase in negative mood decreased the hazard by 1%, and each unit increase in sexual interest raised the hazard by 22%,” she said.
As for interpersonal influences, each unit increase in partner support hiked the hazard of having sex by 25%; each unit increase in relationship quality raised the hazard by 5%, while a recent STI decreased the hazard of having sex and stopping a period of abstinence by 17%.
However, although mood and the influence of a previous STI lowered the risk of ending short periods of abstinence, they had little effect on ending longer periods of abstinence.
The longer that young women at high risk for STIs went without having sex, the more likely they were to remain abstinent, Dr. Ott said.