Female Age at First Sexual Intercourse by Rural-Urban Residence and Birth Cohort.

Background: Previous studies have examined timing of sexual initiation in the United States, but little is known about rural-urban differences in age at first sex.
Methods: We used female respondent data from the National Survey of Family Growth (n = 29,133; 2006-2010 and 2011-2017) to examine age at first vaginal sex with a male partner. We used the Kaplan-Meier estimator and Cox proportional hazard analyses to assess differences in age at first sex by rural-urban residence, overall and stratified by 5-year birth cohorts (1968-1997). Models were adjusted for respondent characteristics and accounted for complex survey design.
Results: Overall, rural women experienced first sex earlier compared with urban women (hazard ratio [HR], 1.20; 95% confidence interval [CI], 1.12-1.29). By age 18, 62% of rural women had experienced first sex, compared with 54% of urban women. After adjustment for respondent characteristics, HRs were attenuated, but rural women were still more likely to have experienced first sex compared with urban women (HR, 1.07; 95% CI, 1.01-1.13). In unadjusted models, rural women were more likely to have experienced first sex compared with urban women for most birth cohorts (HRs ranged from 1.14 to 1.32); for only one cohort (1988-1992) was this association found in the adjusted analysis (HR, 1.23; 95% CI, 1.09-1.39).
Conclusions: Women living in rural areas were generally more likely to report first sex at an earlier age compared with urban women, suggesting that delivery of sexual education and reproductive health services for women in the United States may need to take into account rural-urban residence.
(Copyright © 2019 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.)