Measuring Sex Partner Concurrency: It’s What’s Missing That ... : Sexually Transmitted Diseases (original) (raw)

Article

Nelson, Sara J. MPH*; Manhart, Lisa E. PhD*; Gorbach, Pamina M. MHS, DrPH‡; Martin, David H. MD§; Stoner, Bradley P. MD, PhD∥; Aral, Sevgi O. PhD¶; Holmes, King K. MD, PhD*†**

From the Departments of *Epidemiology, †Medicine, and **Global Health, University of Washington, Seattle, Washington; ‡Department of Epidemiology, University of California, Los Angeles, California; §Louisiana State University Health Sciences Center, New Orleans, Louisiana; ∥Departments of Anthropology and Medicine, Washington University, St. Louis, Missouri; and the ¶US Centers for Disease Control and Prevention

The authors thank all the Young Adults and Partnership Study participants as well as Anthony Archie, Masuma Bahora, Anne Buffardi, Ethel Green, Patrick Marshall, Anita Mehta, Tracy Peto, Lisa Ramachandra, and Khendi White for conducting the interviews. Additional thanks to Jennifer Wroblewski and Sabina Astete for performing the M. genitalium PCR assays, Fred Koch for compiling the Seattle STD clinic data, and Martina Morris for her helpful comments. Finally, the authors thank the clinicians and staff at the Public Health Seattle-King County, St. Louis County, and New Orleans Delgado Sexually Transmitted Diseases Clinics.

Supported by the University of Washington Sexually Transmitted Infections—Topical Microbicides Cooperative Research Center (STI-TM CRC) (NIH/NIAID A131448).

Correspondence: Lisa E. Manhart, PhD, UW Center for AIDS and STD, 325 9th Avenue, Box 359931, Seattle, WA 98104-2499. E-mail: [email protected].

Portions of these data were presented at the 16th Biennial Meeting of the International Society for Sexually Transmitted Diseases Research (ISSTDR), July 10–13, 2005, Amsterdam, The Netherlands (MP-160).

Received for publication November 2, 2007, and accepted March 26, 2007.

Background:

Sex partner concurrency is an important determinant of STI transmission dynamics, yet its measurement is not standardized.

Goal:

We assessed the agreement, compared correlates, and investigated data quality and completeness between 2 common concurrency measures.

Study Design:

Young adults (ages 18–26) attending public STD clinics between 2001 and 2004 in Seattle, St. Louis, and New Orleans, provided data on 2 or more sex partners in a computer-administered survey interview (N = 680). Concurrency with last partner was measured in 2 ways: (a) a direct question about other sexual contacts during the most recent sexual relationship and (b) overlapping start and end dates of the 2 most recent relationships.

Results:

Although 56% reported concurrency by direct questioning and 54% by overlapping dates, the κ statistic for agreement between measures was only fair (0.395). Indeed, 29% of those reporting concurrent partners by the direct question did not do so by overlapping dates and 26% of participants concurrent by overlapping dates were not concurrent by the direct question. Each of the measures had dissimilar correlates, and concurrency data were missing or uninterpretable more often for the overlapping dates measure (21.3%) than the direct question (1.8%).

Conclusions:

Concurrency was common by both measures but the measures were not interchangeable. Although the overlapping dates measure provided information about partnership duration, it is subject to missing or uninterpretable data. The direct question substantially minimized the amount of missing data and may be more appropriate for use with computer-administered survey interview.