Age- and Gender-Specific Estimates of Partnership Formation and Dissolution Rates in the Seattle Sex Survey

Nelson, Sara J.; Hughes, James P.; Foxman, Betsy; Aral, Sevgi O.; Holmes, King K.; White, Peter J.; Golden, Matthew R.

doi:10.1016/j.annepidem.2009.11.003

« Previous Next »Annals of Epidemiology
Volume 20, Issue 4 , Pages 308-317, April 2010

Age- and Gender-Specific Estimates of Partnership Formation and Dissolution Rates in the Seattle Sex Survey

Sara J. Nelson, MPH
- Department of Epidemiology, University of Washington, Seattle
- Address correspondence to: Sara J. Nelson, MPH, University of Washington, Center for AIDS and STD, Harborview Medical Center, 325 9th Ave., Box 359931, Seattle, WA 98104. Tel: (206) 744-8055. Fax: (206) 744-3693.
James P. Hughes, PhD
- Department of Biostatistics, University of Washington, Seattle
Betsy Foxman, PhD
- Department of Epidemiology, University of Michigan, Ann Arbor, MI
Sevgi O. Aral, PhD
- U.S. Centers for Disease Control and Prevention, Atlanta, GA
King K. Holmes, MD, PhD
- Department of Medicine, University of Washington, Seattle
- Department of Global Health, University of Washington, Seattle
Peter J. White, PhD
- Modelling and Economics Unit, Health Protection Agency Centre for Infections, London, UK
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
Matthew R. Golden, MD, MPH
- Department of Epidemiology, University of Washington, Seattle
- Department of Medicine, University of Washington, Seattle

Received 29 May 2009; accepted 25 November 2009. published online 13 January 2010.

Purpose

Partnership formation and dissolution rates are primary determinants of sexually transmitted infection (STI) transmission dynamics.

Methods

The authors used data on persons' lifetime sexual experiences from a 2003–2004 random digit dialing survey of Seattle residents aged 18–39 years (N=1,194) to estimate age- and gender-specific partnership formation and dissolution rates. Partnership start and end dates were used to estimate participants' ages at the start of each partnership and partnership durations, and partnerships not enumerated in the survey were imputed.

Results

Partnership formation peaked at age 19 at 0.9 (95% confidence interval [CI]: 0.76–1.04) partnerships per year and decreased to 0.1 to 0.2 after age 30 for women and peaked at age 20 at 1.4 (95% CI: 1.08–1.64) and declined to 0.5 after age 30 for men. Nearly one fourth (23.7%) of partnerships ended within 1 week and more than one half (51.2%) ended within 12 weeks. Most (63.5%) individuals 30 to 39 years of age had not formed a new sexual partnership in the past 3 years.

Conclusion

A large proportion of the heterosexual population is no longer at substantial STI risk by their early 30s, but similar analyses among high-risk populations may give insight into reasons for the profound disparities in STI rates across populations.

Key Words: Heterosexual, Partnerships, Mathematical Modeling, Random Digit Dialing Survey, Sexually Transmitted Diseases, Epidemiology

Selected Abbreviations and Acronyms: STI, sexually transmitted infection, RDD, random digit dialing, CI, confidence interval