Background:
Studies have demonstrated a relationship between age mixing and reproductive health risk behaviors such as early sex initiation, inconsistent condom use, unplanned pregnancy, and risk of HIV and other STIs. Most of these studies use information reported by women collected during the 1990s. Little is known about trends in these relationships and whether they exist among men.

Objective:
To assess the extent and correlates of age mixing among men and women and examine trends in age mixing patterns among women.

Method:
We use the National Survey of Family Growth (NSFG), nationally representative samples of reproductive-age women (1995) and both men and women (2002) to assess the level of age mixing. Descriptive statistics compare mean (median) age differences across sociodemographic groups. Multivariate analyses examine correlates of age mixing.

Result:
Almost 40% of the 9,272 women in 1995 report male partners at least three years older. The mean (median) age difference is significantly higher for women ages 18-39 than for the youngest women (15-17; p<.001) and oldest women (40-44; p<.001). The mean age difference reported by non-Hispanic blacks is significantly higher than for non-Hispanic whites (p<.02) and other racial/ethnic groups (p<.05). Less educated women and women living in rural areas tend to report significantly older partners than those of more educated women (p<.01) and women living in urban areas (p<.02).

Conclusion:
A substantial amount of age mixing is reported by groups traditionally at high-risk of HIV and other STIs. Age mixing information may be helpful for screening initiatives aimed at decreasing STI rates, their sequelae, and STI transmission.


Implications:
It may be important to ask about age of current/most recent sex partner(s) in order to assess risk for individuals. Age mixing patterns may also help target interventions such as testing, enrollment of high-risk women in empowerment sessions and education sessions for men with younger partners.