## 5 Conclusions and Policy Implications  
These results support current PrEP policy in the United States. The results offer insights into additional assessment of how aggressively PrEP usage should be encouraged compared to the current prescribing trend. This study emphasizes the importance of information about PrEP protocol adherence and analysis of HIV infections that occur while using PrEP. As these data are currently not part of the CDC Atlas case surveillance database, we suggest their future inclusion. Additionally, these models can be applied at a state or local level, instead of nationally, with proper modifications allowing for a comparison at all levels for HIV mitigation and adherence to the current DHAP strategic plan. If modified and applied to smaller groups, these models may be utilized in social sciences to detect disparities between such smaller groups in order to better inform policy.  
As discussed above, the average number of sexual partners per year for the target population may have great importance. These data are not currently provided by the CDC and perhaps are not collected. As our calculations indicate that both proper PrEP usage and reducing the number of partners are important, this could be an important policy thrust. Some subgroups have a disproportionately high risk of becoming infected with HIV and may benefit greatly from PrEP. One such group is the young black MSM group mentioned earlier. The higher HIV rates associated with this group suggest an emphasis should be placed on bridging this disparity by insuring an increase in PrEP awareness and access [19; 24].  
One possible means to address the importance regarding the average number of sexual partners per year while on PrEP but not using condoms would be qualitative studies. These studies could probe PrEP participant understanding, attitudes, and knowledge about medication effectiveness with populations with a larger number of sexual partners, repeated exposures, opportunistic infections, or coinfections (e.g., do patients taking PrEP understand that other STIs may enhance their susceptibility to HIV?) [25; 26; 27]. Another suggestion might be a possible protocol adjustment which includes a questionnaire at follow-up patient visits and interviews to emphasize patient understanding of medication effectiveness when individuals have a larger number of sexual partners.  
**Author Contributions:** Conceptualization, J.L. and R.E.C.; Methodology, J.L. and R.E.C.; Programming, J.L.; Validation, J.L. and R.E.C.; Formal analysis, J.L. and R.E.C.; Investigation, J.L. and R.E.C.; Data curation, J.L.; Writing--original draft preparation, J.L.; Writing--review and editing, J.L. and R.E.C.; Supervision, R.E.C. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
**Institutional Review Board Statement:** Ethics approval was not applicable as the study is computational/mathematical and utilizes anonymous publicly available data with no human or animal subjects.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The data produced and used are provided and code will be made available by request.  
**Conflicts of Interest:** The authors declare no conflict of interest.