**5. Conclusions**

In summary, this research elucidated the complexities of engaging PLWH-SU in treatment. It identified distinct healthcare barrier profiles among PLWH-SU enrolled in CTN-0049, each with different responses to PN interventions. These results help to inform the use of PN programs and provide a more efficient target for PN resources by more narrowly defining the patient population for which PN is effective.

**Supplementary Materials:** The following supporting information can be downloaded at: https:// www.mdpi.com/article/10.3390/jcm12010114/s1, Figure S1: Differences in 3-Class Latent Profile Analysis model by gender. Figure S2: Differences in 3-Class Latent Profile Analysis model by race. Figure S3: Differences in 3-Class Latent Profile Analysis model by southern/non-southern residence.

**Author Contributions:** Conceptualization, S.M.T., L.R.M. and D.J.F.; formal analysis, S.M.T. and D.J.F.; methodology, S.M.T., A.W.C. and D.J.F.; project administration, L.R.M. and D.J.F.; supervision, A.W.C., V.E.H., L.R.M. and D.J.F.; writing—original draft, S.M.T.; writing—review and editing, R.D.S., L.K.G., T.M., L.H., A.R., M.M., P.J., R.M., C.D.R., A.W.C., V.E.H., L.R.M. and D.J.F. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was supported by the National Institutes on Drug Abuse [U10DA013720 and UG1DA013720], the Miami CFAR [P30AI073961], the Emory Center for AIDS Research [P30AI050409] and the Center for HIV and Research in Mental Health [P30MH116867].

**Institutional Review Board Statement:** The parent study received approval from the respective Institutional Review Boards for each study site. However, the current study only used de-identified data and, therefore, was exempt from ethical review.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** CTN 0049 trial data are publicly available on NIDA Data Share: https:// datashare.nida.nih.gov/ (accessed on 7 September 2018).

**Conflicts of Interest:** The authors declare no conflict of interest.

**Disclaimer:** The authors are solely responsible for the content of this article, which does not necessarily represent the official views of the National Institute on Drug Abuse. Dr. Raul Mandler, an employee of the National Institute on Drug Abuse, is an author; he reviewed and approved the manuscript as a part of his authorship role as a Scientific Official.
