Escalation of pharmaceutical opioid use and harm in North America is well-documented, with similar issues emerging in Australia. One response is the development of tamper-resistant formulations of opioids. A potentially tamper-resistant formulation of controlled-release oxycodone was introduced in Australia in April, 2014, rapidly replacing the non-tamper-resistant formulation. Our study is the most systematic and comprehensive examination of the impact of a new opioid formulation to date, assessing the effect of tamper-resistant formulation of controlled-release oxycodone on population-level opioid use and opioid-related harm (ie, overdose, help-seeking, and treatment-seeking); and opioid use, tampering, and preference for the tamper-resistant formulation of controlled-release oxycodone compared with other drugs or formulations among sentinel populations likely to tamper with pharmaceutical opioids.. Please contact the library to request a copy of this article - http://bit.ly/1Xyazai