Introduction

Sexually transmitted infections (STIs) continue to be a common morbidity in the United States (US). While incidence rates of HIV are declining because of biomedical treatment and prevention [1], the number of new infections of common bacterial STIs—such as chlamydia and gonorrhea—remains stagnantly high with indications of increasing prevalence [2]. Moreover, disparities in STI diagnoses by race/ethnicity are unwavering; Black and African Americans remain at five to ten times higher risk of common bacterial STIs compared to their White counterparts [2]. Black men and women are also 3.0 and 1.6 times more likely to experience repeat infection compared to non-Black patients, respectively [3]. Further efforts are needed to mitigate the current trends in bacterial STIs among US-based populations, particularly among those disproportionately affected.

Partner notification services are paramount to reducing STI transmission. Patient-delivered partner therapy (PDPT)—wherein a patient diagnosed with a bacterial STI is given extra medication to deliver to their sexual partners—is one promising mechanism to increase rates of partner treatment, reduce the risk of repeat infections among index patients, and decrease community prevalence [4, 5]. However, the 8% average repeat infection rate among patients provided PDPT in randomized controlled trials [4] indicates further efforts are needed to better prepare patients to give PDPT to their partners and reduce repeat infection risk. Researchers previously identified potential factors that—when aggregated across samples and context [6–15]—fit within constructs of the Information-Motivation-Behavioral skills model [16–19], a framework for understanding sexual health-related behaviors previously validated among STI clinic patients [20–23] and commonly used among many different populations for HIV and STI prevention [24–48]. Specifically, the Information-Motivation-Behavioral skills model posits that individuals must be highly informed, motivated, and behaviorally skilled to initiate HIV/STI prevention behaviors [16–19]. The Information-Motivation-Behavioral skills model serves as an appropriate starting point, but further examination was needed to determine whether the model needed to be adapted to better understand barriers and facilitators of potential PDPT use among STI clinic patients. In this mixed-method study, we sought to: 1) determine barriers and facilitators to PDPT use, 2) develop measurement tools with good construct validity and reliability, and 3) test a theoretical framework on intentions to use PDPT to support the development of a behavioral intervention.

Methods

Results

Phase 3 survey data were screened for obvious satisficing [60] and partial participation, which resulted in the exclusion of 3 survey respondents’ data. The final analytic sample included 197 survey responses and 25 qualitative interviews from patients presenting for HIV/STI counseling and testing at a Midwestern STI clinic. Of the 197 survey respondents, 61% were male. Most (91%) were Black or African American and 93% reported non-Hispanic/Latinx ethnicity. Mean age of the sample was 31.3 years (S.D. = 11.5; range: 18–62), and 41% of the sample had some college education or more. Nearly half (47%) were unemployed, 11% were uninsured, and 54% reported Medicaid/Medicare insurance coverage. Among those who participated in the qualitative components of the study, average patient age was 35.6 years. Most (84%) were Black or African American, and 14 men and 11 women were interviewed.

Triangulation of qualitative and quantitative data resulted in the identification of key themes and a conceptual model explaining intentions to use PDPT. The conceptual model for understanding potential PDPT use, which we’ve titled the Interpersonal-Behavior (I-B) model, is illustrated in Fig 1. Descriptive statistics and scale reliabilities (i.e., Cronbach’s alpha) are presented in Table 1. Variances, covariances, and correlations of standardized indicator variables of the model are presented in Table 2. When a structural equation model was tested (Fig 2), the I-B model had good model fit [χ² (36) = 95.56, p < 0.001; RMSEA = 0.09 (0.07–0.11 90% C.I.); CFI = 0.94; SRMR = 0.05] and explained 49.7% of the variance in PDPT intentions.

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Fig 1. The Interpersonal-Behavior (I-B) model.

https://doi.org/10.1371/journal.pone.0233348.g001

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Fig 2. The structural equation model results testing the Interpersonal-Behavior model on intentions to use PDPT among STI clinic patients.

Notes: * p < 0.05. Non-significant pathways are not shown for interpretability but can be found in the Results section.

https://doi.org/10.1371/journal.pone.0233348.g002

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Table 1. Descriptive statistics and reliabilities of model indicators.

https://doi.org/10.1371/journal.pone.0233348.t001

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Table 2. Variances, covariances, and correlations of indicator variables.

https://doi.org/10.1371/journal.pone.0233348.t002

The hypothesized associations between information, motivation, and social support in the conceptual model could best be described from a 48-year-old Black man: “I've got a lot of support friends. All I have to do is call them and tell them what I'm going through and, information will be flying my way. ‘Hey, you'll get over it. Maybe you should try this, or -.’ … You can always go to your guys and talk to them about sexual issues and stuff.” This quote provides rationale for how social support members could have a role in motivating someone to engage in PDPT use, while also being a source of knowledge and advice. Similarly, patients described the need for more information about STIs, medications, and steps to resuming sexual activity. A 24-year-old Black woman described it here: “You have to have the knowledge about the STD and the medication itself so that you’re ready answer to any questions that [your partners] may have for you.” This woman’s quote provides specific informational needs of patients using PDPT.

Motivation was hypothesized to be associated with PDPT intentions and mediated by behavioral skills. This hypothesis was based on a breadth of discussion with patients about motivating factors that could influence PDPT use. A 29-year-old Black man described how he cared for the health of others: “I [wouldn’t want] the partner having sexual intercourse with somebody else and giving them something too.” Protection beliefs for others was balanced with individual protection beliefs, as mentioned by a 24-year-old Black woman: “We want to get rid of [the STI] and be able to be comfortable and safe and know that OK, well, if we're both clean then if we do decide to have unprotected sex we don't have to have this problem pop up [again] or anything like that.” Additionally, potential PDPT use was influenced by patients’ opinions about what their provider and partner would want them to do. As a 21-year-old Black man stated: “I think that [providers] would feel like this, [PDPT is] a good thing to do. … They got a good opinion on it, so it [would] influence mine in a positive way.”

Social support was hypothesized to be associated with behavioral skills, with behavioral skills mediating the relationship between social support and PDPT intentions. A 21-year-old Black woman described how social support affects one’s confidence (i.e., self-efficacy): “If they had a lot of people in their ear, ‘like you need to tell them,’ then that would kind of like boost their confidence about it.” Although confidence could be influenced by social support members, specific skill needs were apparent. A 25-year-old Black man described the need for communication skills and the ability to answer questions about the infection and medication: “Basic communication skills. Know how to talk to them and know how to say the right things… Knowledge of the situation, the medicine, knowing what you’re gonna say. Not only what you’re gonna say, but how you’re gonna say it.” These objective skill needs were complimented by the need to increase the confidence of the patient through skills-based trainings. Specifically, a 59-year-old White man made the following statement: “[You need to] build up the confidence of the person delivering the med. … So you've got to educate them, kind of train them on how to go about it.” Collectively, these quotes provide context to our modeling results described next.

Structural equation model results are illustrated in Fig 2. Information was significantly associated with both motivation (β = 0.37, p < 0.001) and social support (β = 0.23, p = 0.002) but not behavioral skills (β = 0.04, p = 0.577) or PDPT intentions (β = 0.05, p = 0.391). Motivation was associated with social support (β = 0.64, p < 0.001) and behavioral skills (β = 0.40, p < 0.001), and social support was associated with behavioral skills (β = 0.23, p = 0.025). Behavioral skills were associated with higher PDPT intentions (β = 0.31, p < 0.001), partially mediated the association of motivation with intentions (β_direct = 0.53, p < 0.001; β_indirect = 0.12, 95% CI: 0.03–0.30), and fully mediated the association of social support with intentions (β_direct = -0.11, p = 0.253; β_indirect = 0.07, 95% CI: 0.00–0.21).

Discussion

In this study, STI clinic patients discussed the influence of information, motivational factors, social support, and behavioral skills on hypothetical PDPT use. This qualitative data was then supported by structural equation modeling of the I-B model. Our work suggests an expansion of prior theories to incorporate both social support and interpersonal motivations as the best basis for future interventions targeting PDPT uptake.

We illustrate our proposed model, which we conceptualized based on an adaptation of the Informational-Motivation-Behavioral skills model [16–19] and other theories [61–64], in Fig 1. Although the study of the Information-Motivation-Behavioral skills model is robust and used to explain various HIV/STI prevention behaviors [20–48], research aimed at understanding intentions to use PDPT has been rather limited. Previous study of PDPT [6] was based on the Theory of Planned Behavior [61], incorporating attitudes, subjective norms, and perceived control. We expand on these prior findings to incorporate knowledge and self-efficacy, which were constructs similarly added to the Informational-Motivation-Behavioral skills [16–19] and Integrated Behavioral models [63]. Self-efficacy extends beyond perceived control in a mechanistic role for facilitating engagement in behavior when considered within volitional control. Further, we added social support based on participants’ reflections about the need for additional encouragement, knowledge, and advice. Uniquely, the I-B model combines these factors into a single model useful for understanding interpersonal sexual health related behaviors—the first known theoretical framework of its kind.

Although knowledge was an important construct identified in qualitative analyses, our quantitative modeling only found knowledge associated with motivation and social support. Information was retained as a construct of the I-B model because of the importance of knowledge facilitating motivation; lack of knowledge—such as the lack awareness for the potential of repeat infection without partner treatment, among other items included in the PT-KQ-4 scale measure—was associated with decreased motivation in our model. Moreover, lack of knowledge could be overcome by informational support from social network members, indicating the synergistic role of these constructs. Including the information construct was also supported by prior research, which found many STI clinic patients lacked an understanding of treatment, symptoms, and transmission concepts about bacteria and infections [7]. Thus, knowledge remains an important component of reducing repeat infection risk through partner treatment.

Motivational factors were critical, in line with prior research. Previous research indicated the importance of partner treatment verification as a facilitator to PDPT use [11, 15], and decreasing reinfection risk was perceived as important in research with patient-delivered STI screening kits [8]. Nonetheless, other studies with STI clinic patients found that patients do not always prioritize PDPT as a mechanism to reduce repeat infection; patients declined PDPT because of beliefs that treatment is unnecessary with condom use [14], further indicating the importance of knowledge and its connection to motivation in our analysis. As such, individual protection beliefs need to be supported with protection beliefs for others to ensure PDPT use. Some patients also indicated negative opinions about the partner believed to be responsible for the STI in our study, which decreased their motivation for providing them treatment as similarly identified previously [14]. Patients’ beliefs were also altruistic in our sample; patients had a desire to protect their partner’s health as similarly supported by prior research [7, 8, 11, 14]. Positive partner protection beliefs were identified as potential barriers to PDPT use; a desire for partners to receive face-to-face contact and counseling from a healthcare provider were identified as large barriers to PDPT use in prior research [13, 15]. Therefore, it is necessary to account for multiple forms of protection beliefs in the counseling of patients who receive PDPT.

Facilitating motivations for PDPT use were perceived normative beliefs about PDPT and partner notification. Patients discussed the importance of their and their partners’ health, but the appraisal of their partner’s opinion influenced their own about using PDPT, consistent with normative influences identified in prior research [14]. Motivation-to-comply with the normative influences of healthcare providers were also important; patients generally respected the opinions of their clinicians and support prior claims indicating the positive implications of healthcare providers’ support for PDPT on patient willingness to use it [6].

Social support offered an application to buffer negative life events and stressors. In prior research, individuals reported using social support members to facilitate partner notification and PDPT use [11, 14], indicating the potential instrumental support social network members may have in addition to the informational support identified by our participants. Social support is important because of the complexity to navigating partner notification and treatment delivery.

Behavioral skills fully mediated the relationship between social support and PDPT intentions, indicating social support might not be enough to influence PDPT use without supplemental, skill-based trainings. Patients stressed the need for communication skills training in another STI clinic sample [15], similar to our findings, and the need for more coaching with potential transcripts for how to discuss STIs with their partners as requested by patients previously [14]. Patients in our sample discussed the importance of developing a sense of confidence (i.e., self-efficacy) prior to partner notification and PDPT use, which was previously identified in the partner notification literature [12, 65]. However, no known behavioral interventions have rigorously developed and tested a skills-based training intervention to support PDPT use. Further research is needed to develop and test a comprehensive, supporting intervention for PDPT, incorporating the components of behavioral skills and the other I-B model constructs.

Conclusions

PDPT is an evidence-based method of partner treatment that would benefit from an accompanying behavioral intervention. STI clinic patients attending a Midwestern, public STI clinic discussed themes of information, motivation, social support, and behavioral skills as barriers and facilitators to PDPT use, which supported the development of a conceptual framework. Structural equation modeling of the Interpersonal-Behavioral (I-B) model to explain PDPT intentions had good model fit, supporting the hypothesized theoretical framework. Future intervention work should target I-B model constructs.

Acknowledgments

The authors would like to acknowledge Katie Mosack and Ron Cisler for their contributions during earlier stages of this research. We would also like to thank the Undergraduate Research Assistants who helped with recruiting study participants and data collection, including Katelyn Dallman, Amie Emrys, Ratka Galijot, and Steven Lovejoy, in alphabetical order. Finally, we thank the staff of the City of Milwaukee Health Department, especially Paul Hunter, Irmine Reitl, and Otilio Oyervides, and all the patients who participated in this study.