Relationships between sexual violence and chronic disease: a cross-sectional study

Sexual assault is a traumatic event with potentially devastating lifelong effects on physical and mental health. According to the Centers for Disease Control and Prevention (CDC), one in four women and one in seven men in the U.S. have reported experiencing sexual violence in their lifetime [1, 2]. Sexual violence is defined as any sex act that is perpetrated against someone’s will. It can be classified into four types: a completed sexual act such as rape, 2), an attempted (but not completed) sex act, abusive sexual contact such as intentional touching without consent), and non-contact sexual abuse such as voyeurism, unwanted exposure to exhibitionism, unwanted exposure to pornography, sexual harassment, and threats of sexual violence) [3]. All types of sexual violence involve victims who do not consent, or who are unable to consent or refuse to allow the act. Although similar to intimate partner violence (IPV), sexual violence may involve a perpetrator who is unknown to the victim and pertains specifically to forcible sex acts [4]. While the economic burden of sexual violence is difficult to quantify due to limited data, the existing research indicates that the costs are substantial. With a total estimated cost of $127 billion a year (excluding the cost of child sexual abuse) [5], rape is the most costly of all violent crimes.

Despite the high prevalence and economic burden of sexual assault, few studies have investigated the associations between sexual violence and chronic health conditions, which are major causes of morbidity and mortality. Seventy percent of U.S. deaths each year are attributed to chronic diseases, with heart disease, cancer, and stroke accounting for more than 50 percent of all deaths [6]. Research has demonstrated that individuals who experience sexual assault during childhood are more likely to engage in risky behaviors later in life, such as smoking, alcohol and drug abuse [7], and disordered eating habits [8], which may increase the risk of developing a chronic disease. Such maladaptive behaviors in this population have been attributed to poor self-esteem, stress, mental illness such as post-traumatic stress disorder [9–11], depression [11, 12]), and sleep disorder [13]. A growing body of research suggests that a child’s development and adult functioning can be profoundly impacted by sexual violence. Nearly half of sexually victimized females were raped before the age of 18, and more than 25 percent of sexually victimized males were raped before the age of 10 [14]. A longitudinal study of sexually victimized girls found that sexual abuse was associated with disruptions in the hypothalamic-pituitary-adrenal axis, which is proposed to result in increased susceptibility to stress later in life [15]. A 2010 meta-analysis supports the hypothesis that childhood sexual abuse is related to higher rates of physical health symptoms, including poor general health, gynecologic pain, cardiopulmonary symptoms, and obesity [16]. Similar pathways linking sexual violence that occurs in adulthood to chronic disease may exist. As part of a large public health survey, Smith & Breiding [17] used data from 25 states/territories that administered the Behavioral Risk Factor Surveillance Survey (BRFSS) sexual violence module in 2005 [17]. The BRFSS is a state-level surveillance system of health-related risk behaviors, chronic health conditions, and use of preventive services among adults 18 years and older. Smith & Breiding reported that non-consensual sex among women and men was associated with smoking, excessive alcohol use, Human Immunodeficiency Virus (HIV) risk factors such as use of intravenous drugs, treated for sexually transmitted infection, prostitution, engaged in anal sex without a condom in the past year, arthritis, asthma, activity limitations, high cholesterol, stroke, and heart disease. Women with a history of sexual violence were more likely to experience a heart attack than women without such a history. Similarly, Black et al. [14] found that sexually victimized women were more likely to have asthma, irritable bowel syndrome, and diabetes, and were more likely to experience chronic pain, frequent headaches, and difficulty sleeping. Another study found that women with a history of sexual assault were more likely to smoke, have high cholesterol and hypertension, and to be obese [8].

The aim of this study was to identify the relationship of sexual violence and chronic disease using current Kansas state-level BRFSS data which includes mental health and additional behavioral risk behaviors that have not been examined previously. The results of this study could support the establishment of public health strategies that implement primary, secondary, and tertiary prevention for chronic disease and sexual violence. In addition, the findings may suggest future avenues of research that will further elucidate this relationship.

The prevalence of sexual violence among women in Kansas was nearly nine percent, which was lower than the 18.5 percent prevalence reported in a multistate survey [17]. This difference may be explained by the fact that the multi-state survey measured both attempted and completed sexual violence, while this study only measured completed sexual assault. The current study demonstrated that a history of sexual violence was more common among certain demographic groups, including women who were divorced or separated, women with an income less than $15,000, women who were unable to work, women younger than 65 years of age, and women who lived in a semi-urban area. This is consistent with data from the Bureau of Justice Statistics that found that women who were younger, divorced or separated, and lived in low-income households were most likely to experience sexual assault [18]. The authors found no significant differences in history of sexual assault by education level, health insurance status, or race/ethnicity.

Study findings indicate that sexual violence is linked to several adverse health behaviors, chronic health conditions and mental health conditions, even after adjusting for demographic characteristics. These findings support previous reports linking sexual victimization, risk behaviors, and long-term health conditions [7–9, 16, 17]. Unlike one previous study, the association between HIV risk factors and sexual assault history was not significant after adjusting for demographic characteristics [17].

Given the limitations of the cross-sectional study design, there was no way to establish causal or temporal relationships between sexual violence, demographic characteristics, and health behaviors and conditions. For example, men and women with physical and mental disabilities are three to four times more likely to be sexually assaulted than individuals without a disability [19, 20]. The relationship between alcohol use and sexual assault is also complex; excessive drinking has been found to be a significant cause and consequence of sexual assault [7, 21, 22]. While the association between excessive drinking and sexual assault is well known, alcohol can be a contributing factor in all types of interpersonal violence (i.e., intimate partner violence, assault, homicide) [23, 24].

While the mechanism by which sexual violence, demographic characteristics, and health behaviors and conditions are related remains to be elucidated, it is important to note that sexual violence is overwhelmingly experienced by younger women (80 percent of victims reported that they were raped before 25 years of age [14]) while chronic health problems typically arise later in life. Therefore, sexual victimization likely preceded health conditions for most respondents. One possible explanation for the relationship is that sexual violence causes serious psychological distress, such as post-traumatic stress disorder (PTSD) and depression, which is linked to high-risk behaviors. For example, a 2008 study of college-aged women found that PTSD symptoms mediated the relationship between sexual assault and adverse health events [10]. A history of childhood sexual abuse has been associated with persistent, chronic major depression [25].

Another potential explanation for the relationship between sexual assault and chronic disease is that trauma negatively impacts the body’s regulatory and immune functioning. Black et al. [14] reported that women who were sexually victimized were more likely to experience stress and difficulty sleeping. Insufficient sleep has been linked to numerous chronic conditions, including diabetes [26] and obesity [27]. It has been proposed that insufficient sleep adversely affects the function of the hypothalamus, which regulates appetite and the expenditure of energy [27].

This study is not without limitations. This study has no direct comparisons to other studies because the authors used an abbreviated form of the sexual violence module of BRFSS. Due to the limitations of survey questions, the authors could not evaluate specific details (e.g., co-occurring abuse, at what age a victim had experienced the sexual assault, the nature of the sexual assault, whether or not a victim experienced multiple incidents of sexual assault) that might influence the long-term health outcomes of sexual violence.

Another limitation of the study is that the variables were assessed via self-report and were not verified by medical records, which may lead to underreporting. However, sexual assault is likely also underreported in the medical record, since many incidents of sexual violence go unreported and unrecognized [28]. In addition, the 2011 BRFSS was a telephone survey of only residential households, therefore people with a cell phone or without a landline telephone were excluded from state-added sexual violence module arm of the study. Individuals who only have cell phones are more likely to be younger, have lower incomes, and report binge drinking [29]. These demographic factors are associated with increased prevalence of sexual violence [1, 14, 17]. Because cell phone respondents were not included in the sample, this study likely underreports the prevalence of sexual violence among women in Kansas.

This is the first study to describe the health behaviors and conditions of women in Kansas who have ever experienced sexual violence. It is essential to include questions about sexual violence on future iterations of the BRFSS in order to track changes in the prevalence of sexual violence over time and associations with health behaviors and conditions. Due to the cross-sectional study design in the current study, future longitudinal studies are needed to demonstrate temporality between these factors.

The detrimental effects of sexual violence on victims and society cannot be overstated. Many sexually victimized individuals experience lifelong psychological and physical hardships. Therefore, the findings from this study have important implications for policies and practices related to primary, secondary, and tertiary prevention, and provides further evidence that it is critical to change the social paradigm that supports sexual violence. While more research is needed to determine the cost-benefit of universal screening for sexual assault, it is crucial that healthcare providers are trained in sexual violence and sexual violence management and that they are made aware of the associated health risk behaviors and conditions among victims of sexual assault so that they can take proactive, preventive measures. As recommended by the World Health Organization’s report on Responding to Intimate Partner Violence and Sexual Violence Against Women [30] healthcare providers can listen to survivors of sexual assault without pressure for a response to disclose information, offering comfort to help alleviate or reduce anxiety, and provide written information on coping strategies for dealing with severe stress.

Associations between sexual assault and chronic disease in Kansas emphasize the need to focus not only on the physical and psychological health consequences related to victimization, but also on potential chronic disease consequences and the overall impact of sexual violence on the health care system. In addition, results from this study provide rationale for collaborations between sexual violence, chronic disease, and health risk behaviors programs to develop prevention and intervention strategies that address this important public health problem.