1. Substance Abuse and Mental Health Services Administration: Results from the 2019 National Survey on Drug Use and Health: Detailed tables. Rockville, MD: Center for Behavioral Health Statistics and Quality, Substance Abuse and Mental Health Services Administration; 2020.
2. Mattson CL, Tanz LJ, Quinn K, Kariisa M, Patel P, Davis NL: Trends and Geographic Patterns in Drug and Synthetic Opioid Overdose Deaths - United States, 2013-2019. MMWR Morb Mortal Wkly Rep 2021, 70:202-207.
3. Al-Tayyib A, Koester S, Langegger S, Raville L: Heroin and Methamphetamine Injection: An Emerging Drug Use Pattern. Subst Use Misuse 2017, 52:1051-1058.
4. Chan B, Freeman M, Ayers C, Korthuis PT, Paynter R, Kondo K, Kansagara D: A systematic review and meta-analysis of medications for stimulant use disorders in patients with co-occurring opioid use disorders. Drug Alcohol Depend 2020, 216:108193.
5. Ellis MS, Kasper ZA, Cicero TJ: Twin epidemics: The surging rise of methamphetamine use in chronic opioid users. Drug Alcohol Depend 2018, 193:14-20.
6. Ciccarone D, Mars S, Rosenblum D, Unick J: Of speedballs and goofballs: Stimulants and the 4th wave of the opioid crisis 2019.
7. Zibbell JE, Asher AK, Patel RC, Kupronis B, Iqbal K, Ward JW, Holtzman D: Increases in Acute Hepatitis C Virus Infection Related to a Growing Opioid Epidemic and Associated Injection Drug Use, United States, 2004 to 2014. Am J Public Health 2018, 108:175-181.
8. Schranz AJ, Barrett J, Hurt CB, Malvestutto C, Miller WC: Challenges Facing a Rural Opioid Epidemic: Treatment and Prevention of HIV and Hepatitis C. Curr HIV/AIDS Rep 2018, 15:245-254.
9. Rajbhandari-Thapa J, Zhang D, Padilla HM, Chung SR: Opioid-Related Hospitalization and Its Association With Chronic Diseases: Findings From the National Inpatient Sample, 2011-2015. Prev Chronic Dis 2019, 16:E157.
10. Westergaard RP, Stockman LJ, Hyland HA, Guilfoyle SM, Fangman JJ, Vergeront JM: Provider Workforce Assessment in a Rural Hepatitis C Epidemic: Implications for Scale-up of Antiviral Therapy. J Prim Care Community Health 2015, 6:215-217.
11. Schafer KR, Albrecht H, Dillingham R, Hogg RS, Jaworsky D, Kasper K, Loutfy M, MacKenzie LJ, McManus KA, Oursler KA, et al: The Continuum of HIV Care in Rural Communities in the United States and Canada: What Is Known and Future Research Directions. J Acquir Immune Defic Syndr 2017, 75:35-44.
12. Pellowski JA: Barriers to care for rural people living with HIV: a review of domestic research and health care models. J Assoc Nurses AIDS Care 2013, 24:422-437.
13. Feyman Y, Provenzano F, David FS: Disparities in Clinical Trial Access Across US Urban Areas. JAMA Netw Open 2020, 3:e200172.
14. Carroll KM, Ball SA, Jackson R, Martino S, Petry NM, Stitzer ML, Wells EA, Weiss RD: Ten take home lessons from the first 10 years of the CTN and 10 recommendations for the future. Am J Drug Alcohol Abuse 2011, 37:275-282.
15. Steinman L, Hammerback K, Snowden M: It Could Be a Pearl to You: Exploring Recruitment and Retention of the Program to Encourage Active, Rewarding Lives (PEARLS) With Hard-to-Reach Populations. Gerontologist 2015, 55:667-676.
16. Strong D, Del Grosso P, Bhatt J, Phillips S, Scheppke K: Rural Research Needs and Data Sources for Selected Human Services Topics. Volume 2: Data Sources. 2005.
17. Wakim PG, Rosa C, Kothari P, Michel ME: Relation of study design to recruitment and retention in CTN trials. Am J Drug Alcohol Abuse 2011, 37:426-433.
18. Clinical Trials [https://www.nih.gov/research-training/clinical-trials]
19. Volkow N: How People with Substance Use Disorders (SUDs) Can Lend a Needed Hand in Addiction Research. In Nora's Blog (Volkow N ed. Bethesda, MD: National Institute on Drug Abuse; 2019.
20. Batista P, Deren S, Banfield A, Silva E, Cruz M, Garnes P, Cleland CM, Mehandru S, LaMar M, Markowitz M: Challenges in Recruiting People Who Use Drugs for HIV-Related Biomedical Research: Perspectives from the Field. AIDS Patient Care STDS 2016, 30:379-384.
21. Kim SH, Tanner A, Friedman DB, Foster C, Bergeron CD: Barriers to clinical trial participation: a comparison of rural and urban communities in South Carolina. J Community Health 2014, 39:562-571.
22. Jones JM, Nyhof-Young J, Moric J, Friedman A, Wells W, Catton P: Identifying motivations and barriers to patient participation in clinical trials. J Cancer Educ 2006, 21:237-242.
23. Ickovics JR, Meisler AW: Adherence in AIDS clinical trials: a framework for clinical research and clinical care. J Clin Epidemiol 1997, 50:385-391.
24. Young AM, Stephens DB, Khaleel HA, Havens JR: Hepatitis C vaccine clinical trials among people who use drugs: potential for participation and involvement in recruitment. Contemp Clin Trials 2015, 41:9-16.
25. Levy V, Evans JL, Stein ES, Davidson PJ, Lum PJ, Hahn JA, Page K: Are young injection drug users ready and willing to participate in preventive HCV vaccine trials? Vaccine 2010, 28:5947-5951.
26. Feldman S, Ammar W, Lo K, Trepman E, van Zuylen M, Etzioni O: Quantifying Sex Bias in Clinical Studies at Scale With Automated Data Extraction. JAMA Network Open 2019, 2:e196700-e196700.
27. Lancaster KE, Cooper HLF, Browning CR, Malvestutto CD, Bridges JFP, Young AM: Syringe Service Program Utilization, Barriers, and Preferences for Design in Rural Appalachia: Differences between Men and Women Who Inject Drugs. Subst Use Misuse 2020:1-10.
28. Jones AA, Gicas KM, Seyedin S, Willi TS, Leonova O, Vila-Rodriguez F, Procyshyn RM, Smith GN, Schmitt TA, Vertinsky AT, et al: Associations of substance use, psychosis, and mortality among people living in precarious housing or homelessness: A longitudinal, community-based study in Vancouver, Canada. PLoS Med 2020, 17:e1003172.
29. Witte TH, Wright A, Stinson EA: Factors Influencing Stigma Toward Individuals Who Have Substance Use Disorders. Subst Use Misuse 2019, 54:1115-1124.
30. Brown SA: Stigma towards Marijuana Users and Heroin Users. J Psychoactive Drugs 2015, 47:213-220.
31. Smith LR, Earnshaw VA, Copenhaver MM, Cunningham CO: Substance use stigma: Reliability and validity of a theory-based scale for substance-using populations. Drug Alcohol Depend 2016, 162:34-43.
32. National Rural Opioid Initiative: HIV, HCV and Related Comorbidities in Rural Communities Affected by Opioid Injection Drug Epidemics in the United States: Building Systems for Prevention, Treatment and Control (UG3/UH3). NIDA; 2018.
33. About the Appalchian Region [https://www.arc.gov/about-the-appalachian-region/]
34. U.S. Census Bureau: 2014-2018 American Community Survey 5-Year Data Profile. (U.S. Census Bureau ed.; 2020.
35. Van Handel MM, Rose CE, Hallisey EJ, Kolling JL, Zibbell JE, Lewis B, Bohm MK, Jones CM, Flanagan BE, Siddiqi AE, et al: County-Level Vulnerability Assessment for Rapid Dissemination of HIV or HCV Infections Among Persons Who Inject Drugs, United States. J Acquir Immune Defic Syndr 2016, 73:323-331.
36. Wilson N, Kariisa M, Seth P, Smith Ht, Davis NL: Drug and Opioid-Involved Overdose Deaths - United States, 2017-2018. MMWR Morb Mortal Wkly Rep 2020, 69:290-297.
37. Rosenblatt RA, Andrilla CH, Catlin M, Larson EH: Geographic and specialty distribution of US physicians trained to treat opioid use disorder. Ann Fam Med 2015, 13:23-26.
38. P. Todd Korthuis, Young A: The Peer-Based Retention of People Who Use Drugs in Rural Research (PROUD-R2). Oregon Health and Science University; 2019.
39. Harris PA, Taylor R, Thielke R, Payne J, Gonzalez N, Conde JG: Research electronic data capture (REDCap)--a metadata-driven methodology and workflow process for providing translational research informatics support. J Biomed Inform 2009, 42:377-381.
40. Clayton JA, Tannenbaum C: Reporting Sex, Gender, or Both in Clinical Research? JAMA 2016, 316:1863-1864.
41. Robbins NB, Heiberger RM: Plotting Likert and Other Rating Scales. In Proceedings of the Joint Statistical Meetings; Arlington, VA. Edited by Association AS. 2012
42. Concato J, Peduzzi P, Holford TR, Feinstein AR: Importance of events per independent variable in proportional hazards analysis. I. Background, goals, and general strategy. J Clin Epidemiol 1995, 48:1495-1501.
43. Peduzzi P, Concato J, Feinstein AR, Holford TR: Importance of events per independent variable in proportional hazards regression analysis. II. Accuracy and precision of regression estimates. J Clin Epidemiol 1995, 48:1503-1510.
44. Peduzzi P, Concato J, Kemper E, Holford TR, Feinstein AR: A simulation study of the number of events per variable in logistic regression analysis. J Clin Epidemiol 1996, 49:1373-1379.
45. R Core Team: R: A Language and Environment for Statistical Computing. Vienna, Austria: R Foundation for Statistical Computing; 2020.
46. Heiberger RM: HH: Statistical Analysis and Data Display: Heiberger and Holland.; 2020.
47. Rhodes T: Risk environments and drug harms: A social science for harm reduction approach. International Journal of Drug Policy 2009, 20:193-201.
48. Pullen E, Oser C: Barriers to substance abuse treatment in rural and urban communities: counselor perspectives. Subst Use Misuse 2014, 49:891-901.
49. Long C, DeBeck K, Feng C, Montaner J, Wood E, Kerr T: Income level and drug related harm among people who use injection drugs in a Canadian setting. Int J Drug Policy 2014, 25:458-464.
50. Fry C, Dwyer R: For love or money? An exploratory study of why injecting drug users participate in research. Addiction 2001, 96:1319-1325.
51. Wells EA, Saxon AJ, Calsyn DA, Jackson TR, Donovan DM: Study results from the Clinical Trials Network's first 10 years: where do they lead? J Subst Abuse Treat 2010, 38 Suppl 1:S14-30.
52. Thompson RG, Jr., Wall MM, Greenstein E, Grant BF, Hasin DS: Substance-use disorders and poverty as prospective predictors of first-time homelessness in the United States. Am J Public Health 2013, 103 Suppl 2:S282-288.
53. Korte JE, Rosa CL, Wakim PG, Perl HI: Addiction treatment trials: how gender, race/ethnicity, and age relate to ongoing participation and retention in clinical trials. Subst Abuse Rehabil 2011, 2:205-218.
54. Virani S, Burke L, Remick SC, Abraham J: Barriers to recruitment of rural patients in cancer clinical trials. J Oncol Pract 2011, 7:172-177.
55. Stack E, Leichtling G, Larsen JE, Gray M, Pope J, Leahy JM, Gelberg L, Seaman A, Korthuis PT: The Impacts of COVID-19 on Mental Health, Substance Use, and Overdose Concerns of People Who Use Drugs in Rural Communities. J Addict Med 2020.
56. Baker R, Leichtling G, Hildebran C, Pinela C, Waddell EN, Sidlow C, Leahy JM, Korthuis PT: "Like Yin and Yang": Perceptions of Methamphetamine Benefits and Consequences Among People Who Use Opioids in Rural Communities. J Addict Med 2020.
57. Friedman DB, Bergeron CD, Foster C, Tanner A, Kim SH: What do people really know and think about clinical trials? A comparison of rural and urban communities in the South. J Community Health 2013, 38:642-651.