Increased rates of incarceration may mean more sexual partners and STDs Interview with:

Andrea K. Knittel, MD, PhD PGY-3, Department of Obstetrics, Gynecology, and Reproductive Sciences University of California, San Francisco

Dr. Andrea Knittel

Andrea K. Knittel, MD, PhD
PGY-3, Department of Obstetrics, Gynecology, and Reproductive Sciences
University of California, San Francisco

Medical Research: What is the background for this study?

Dr. Knittel: The United States has the highest rate of incarceration in the world, and many studies have shown that involvement in the criminal justice system may be a risk factor for HIV/AIDS or other STDs. For example, some studies have found that in areas with high rates of incarceration, rates of STDs are higher, and others have shown that incarcerated individuals are more likely to have higher rates of concurrent sexual partnerships and a greater number of sexual partners. This may happen because of increased rates of partnership dissolution due to physical and emotional distance, as well as a desire on the part of formerly incarcerated men for an increased number of sexual partners to “make up for lost time,” which some studies have suggested. In addition, the female partners of incarcerated men may rely on other relationships, including new sexual partners, for emotional and financial support while their partners are incarcerated, whether their relationships end permanently or temporarily or they maintain their relationships through visits and calls.

Very few studies have been able to look at community level effects of incarceration, however, because it is difficult to gather data at this level. This study uses an agent-based model, a computational approach that provide a closed system in which to test hypotheses. An agent-based model is a computer simulation that creates a small community (250 “agents” or simulated people) in which the agents can date and have sexual relationships. The model used in this paper has been shown previously to be similar to young people in the US. The experiment in this study was to run the model without incarceration and see how many partners men and women in the community had, and then add incarceration into the model and see what happened. Based on data from other studies, when men in the model were incarcerated they had a slightly higher risk of ending a relationship and became slightly less desirable as partners.

Medical Research: What are the main findings?

Dr. Knittel: The model shows that even without change preferences about sexual relationships and sexual partners that simply removing men and returning them to the community frequently can increase the number of sexual partners that both men and women have in the community.

Medical Research: What should clinicians and patients take away from your report?

Dr. Knittel: The results we describe in this study, and the work that led up to it suggests that asking patients about recent involvement in the criminal justice system or a partner’s incarceration or arrest may provide important information about sexual risk. In addition, the study demonstrates that individuals who have been involved in the criminal justice system do NOT need to have different preferences or desires to have different patterns of sexual partnership as a result of incarceration; this means that they should not be viewed as sexually deviant or abnormal, or be blamed individually for the sexual networks that are a result of this significant social force.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Knittel: Future work should include collection of community- and sexual network-level data that can document whether the sorts of changes in network structure that were seen in the computational model are observed in social groups that include incarcerated individuals, and their impact on disease spread. 

Medical Research: Is there anything else you would like to add?

Dr. Knittel: Computational models offer a digital petri dish in which experiments that would be impossible in the real world are absolutely doable. The results from computational models can never be applied thoughtlessly to the real world, but are thought-provoking and demonstrate what is possible. It will be interesting to continue to work to demonstrate that these “in silico” experiments are applicable to these potentially at risk communities.


Modeling the community-level effects of male incarceration on the sexual partnerships of men and women

Modeling the community-level effects of male incarceration on the sexual partnerships of men and women” by Andrea K. Knittel, Rachel C. Snow, Rick L. Riolo, Derek M. Griffith and Jeffrey Morenoff (doi: doi:10.1016/j.socscimed.2015.11.005). Social Science & Medicine, Volume 147 (December 2015),

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Andrea K. Knittel, MD, PhD (2016). Release From Incarceration May Mean More Sexual Partners and STDS

Last Updated on February 16, 2016 by Marie Benz MD FAAD