PROJECT SUMMARY/ABSTRACT Over the past 15 years, the United States has seen the emergence of an opioid epidemic with drug overdose ranking as the most common cause for accidental death. The rise in drug overdose deaths mirrors the rise in legal opioid prescribing. Unfortunately, most persons using opioids for non-medical purposes obtain them from a family member or friend who was legitimately prescribed opioids. While significant attention has been devoted to prescribing recommendations for individuals with chronic pain and for acute post-surgical pain, much less attention has been given to post-surgical opioid prescribing after hospital discharge. As the most common abdominal surgery in the United States, cesarean birth is the ideal setting to examine methods to reduce unused prescribed opioids. My preliminary work demonstrates that most women have unused opioids after cesarean birth, however a significant proportion of women use all opioids and have unmet pain needs. In addition, current opioid prescribing practices appear to be largely based on prescriber habits rather than patient need. This body of work endeavors to 1) characterize post-discharge opioid use patterns and identify demographic and obstetric variables associated with differential use 2) create and validate a clinical decision support tool that predicts customized post-discharge opioid need and 3) conduct a pilot randomized clinical trial comparing prescribing guided by the CDS tool to standard care to test whether this tool reduces unused opioids without increasing unmet pain after cesarean birth. The overarching objective of this mentored career development experience is to emerge as an independent clinical investigator leading a multidisciplinary research program to improve opioid prescribing after hospital discharge. To accomplish this goal, I will augment my prior research training with advanced coursework and skills development in predictive modeling and conducting clinical trials as well as leadership training focused on opioid prescribing and maternal and infant public health systems. Throughout the award period, the I will work closely with a multidisciplinary team of mentors and advisors—including experts in obstetrics and gynecology, biostatistics, anesthesiology, public health, and epidemiology—to carry out my stated career objectives and specific aims.