Concurrent Sexual Partnerships among Youth in Urban Kenya: Prevalence and Partnership Effects

Published in the September 2010 edition of the journal Population Studies, this 22-page research paper shares findings of a study to examine the prevalence of multiple concurrent partnerships (MCP) among youth in Kisumu, Kenya. Using life history calendars as a tool for gathering information, the study estimated that prevalence is relatively low with 13.2% of females and 20% of males aged 18-24 having experienced concurrency in the last ten years. The research found that characteristics of initial partnerships are important factors affecting entry into a second (concurrent) relationship. Among females, marriage decreases and geographic separation from an initial partner increases the risk of concurrency. Among males and females, casual relationships and having initial partners who have other sexual partners increase the risk, suggesting that concurrency expands one's egocentric sexual network and bridges additional networks involving partners’ other partners.

The paper explains that data collected using life history calendars could be particularly beneficial for estimating the prevalence and correlates of concurrency. The calendar method aids respondents to accurately recall the occurrence, sequence, and timing of past events. They say that the resulting descriptive statistics provide insight into detailed aspects of concurrency and how they vary by sex. Second, the researchers employed survival analysis to examine the risk of entering concurrency as a function of the characteristics of individuals and their initial sexual partnerships at the time of concurrency. The data used for the analyses come from the Urban Life among Youth in Kisumu Project conducted in 2007.

The study found that the mean age at first concurrency for females is 18.1 years (median 18.3 years) and 18.5 years (median 18.3 years) for males. Despite early ages at first concurrency, over 80% of both males and females had only one episode in the last ten years. Of the remainder, all but one of the females and approximately 10% of males had two episodes, and another 10% of males had three or four episodes. Overall, approximately 90% of young women's episodes and approximately 80% of young men's episodes involved two ongoing sexual partnerships simultaneously. The percentage of episodes involving three sexual partnerships is lower for females than for males (6.4% versus 16.8% of episodes in the last ten years, respectively), and one episode among young males involved four partnerships.

The duration of concurrency episodes is highly variable: 34% of women's and 55.8% of men's episodes in the last ten years lasted one month, while 19.1% of women's and 12.6% of men's episodes lasted over one year. On average, men's episodes (5.2 months) are shorter than women's (7.0 months). The pattern of longer concurrency episodes for females holds for the results in last year and last five years as well.

The authors say that these results suggest that the prevalence of concurrency may not be the main driver of high rates of HIV infection in general and much higher rates among young females in particular within this population. Other dimensions of concurrency, such as the duration, type, and number of partners, or patterns of condom use and coitus within concurrent partnerships may be important determinants of HIV infection. For example, while the study found that casual initial partnerships increase the risk of concurrency, they may also be characterised by less condom use, which could facilitate the spread of infection across overlapping partnerships. Overall, the low levels of concurrency and important variation in concurrency attributes by gender underscore the need for further investigation into the types and dimensions of concurrency that are associated with increasing or decreasing the spread of HIV/AIDS.

The authors explain that the survival analysis found several differences between young men and women in their risk factors of entering concurrency, with older ages at sexual debut increasing the risk for young women, and age and recent migration increasing the risk for young men. Findings suggest that incidents of concurrency often catalyse more concurrent partnerships, bridging additional networks involving partners' other partners. The report states that this pattern of concurrency could be a key factor in the spread of HIV in this population and should be explored in future research.

They also found that geographic distance from an initial partner increased the risk of concurrency (for females only); however, infrequent sexual intercourse did not. Many partnerships continue despite separation, and new relationships are formed in the interim, thereby expanding sexual networks further across space. Overall, results support the view that research and interventions should focus beyond the individual-level determinants of concurrency and HIV infection and take partnership dynamics into account.

Finally, the study highlights the need for continued efforts to collect accurate and complete data on partnership histories in survey research. The Relationship History Calendar was specially designed to tackle the well-documented problems with reliability and validity of reporting on sexual behaviour, and future research should refine and implement the method in multiple settings and age groups.