Cohort profile: POPPY II - a population-based cohort examining the patterns and outcomes of prescription opioid use in New South Wales, Australia.

The POPPY II cohort will be updated periodically, both extending the follow-up duration of the existing cohort, and including new individuals initiating opioids. The POPPY II cohort will allow a range of aspects of opioid utilisation to be studied, including long-term trajectories of opioid use, development of a data-informed method to assess time-varying opioid exposure, and a range of outcomes including mortality, transition to opioid dependence, suicide and falls. The duration of the study period will allow examination of population-level impacts of changes to opioid monitoring and access, while the size of the cohort will also allow examination of important subpopulations such as people with cancer, musculoskeletal conditions or opioid use disorder.