Sexual activity and weekly contraceptive use among young adult women in Michigan

Abstract

Past studies on the influence of sexual activity on contraceptive behaviours are inconclusive, relying heavily on cross-sectional data. We used a population-based longitudinal sample of young women in Michigan to evaluate weekly associations between sexual activity and contraceptive use at three levels of measurement: comparing between women, among individual women’s partnerships, and from week to week within partnerships. We used multinomial logistic regression accounting for correlations within partnerships and women. Relative to use of least effective methods, weekly sexual activity was significantly associated with increased use of condoms, pills, and highly effective methods. For pills and highly effective methods, partnership-, woman-, and week-level effects were similar. For condoms, there was no significant woman-level effect. Evidence of immediate effects of sexual activity on contraceptive use highlights the importance of longitudinal data. These dynamics may be diluted or missed altogether when relying on cross-sectional data approaches that compare groups of individuals.

Keywords:

• contraceptive use
• sexual activity
• sexual partners
• young adults
• longitudinal studies

Notes

1 Please direct all correspondence to Susannah E. Gibbs, 2631 SW Campus Way, Corvallis, OR 97331, USA; or by E-mail: [email protected]

2 Susannah E. Gibbs is currently at the College of Public Health and Human Sciences, Oregon State University; when this paper was written she was in the Department of Population, Family and Reproductive Health, Johns Hopkins Bloomberg School of Public Health. Yasamin Kusunoki is at the School of Nursing, Department of Systems, Populations and Leadership, Institute for Social Research, Population Studies Center and Survey Research Center, University of Michigan. Elizabeth Colantuoni is in the Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health. Caroline Moreau is in the Department of Population, Family and Reproductive Health, Johns Hopkins Bloomberg School of Public Health. The Relationship Dynamics and Social Life study was funded by two grants from the National Institute of Child Health and Human Development [R01 HD050329, R01 HD050329-S1, PI Barber].