PROJECT SUMMARY This Diversity Supplement is designed to support and enhance the diversity of the health-related research workforce through the training of Sarah Clingan, PhD., a Latinx/Native American Addiction Researcher. The supplement is complementary to the parent grant, an R01 on overdose and opioid use disorder in Los Angeles County, funded under the National Institutes of Health's Helping End Addiction Long-Term Initiative. Dr. Clingan has a strong research background in addiction sciences that will continue to develop under the mentorship of Dr. Chelsea Shover (primary mentor, epidemiologist, and MPI of parent grant), Dr. Steve Shoptaw (senior co-mentor) a licensed psychologist and Director of the Center for Behavioral and Addiction Medicine at UCLA, and Dr. David Goodman-Meza (co-mentor, physician-scientist, and MPI of parent grant). These three mentors have a strong record of collaboration and a track record of mentoring underrepresented scholars. Through this supplement, Dr. Clingan will obtain training and mentorship across three training objectives. The first will focus on gaining skills and experience using natural language processing (NLP) and machine learning approaches. She will additionally gain skills in designing research projects using real-world data to study polysubstance use. Her third and final training objective is professional development activities that will culminate in her writing a K01 career development award, using the findings generated by the Diversity Supplement as pilot data. The research component of the Diversity Supplement will use electronic health record (EHR) data collected via the parent grant to identify people with polysubstance use and create models of healthcare utilization among those who co-use opioids and stimulants. Specifically, the aims of the Diversity Supplement research plan are to: 1) develop an algorithm to identify people with polysubstance use (opioids and stimulants) in EHR data; 2) Characterize healthcare utilization among those who co-use opioids and stimulants using NLP-based approaches. These results will improve our understanding of polysubstance use in a county with a very high burden of overdose involving fentanyl and stimulants, and contribute to our understanding of the gaps in healthcare services for this population in Los Angeles County. The Diversity Supplement findings will also provide preliminary data for Dr. Clingan's planned K01 application. This award will provide Dr. Clingan with the support, mentorship, and protected time that will enhance her training at UCLA and facilitate her transition to become an independent researcher.

PROJECT NARRATIVE This Diversity Supplement will provide important training for Sarah Clingan, PhD., a Latinx/Native American Addiction Researcher, and will directly contribute to promoting the diversity of researchers in NIDA's portfolio. Through secondary data analysis of data collected from the parent grant, this supplement will develop an algorithm to identify people with polysubstance use in EHR records and will identify healthcare utilization among those who co-use opioids and stimulants using NLP-based approaches. The long-term goal of this supplement is to identify the treatment needs of disadvantaged communities through accurate records and equip Dr. Clingan to become an independent investigator.