The Opioid Cohort Consortium (OPICO) was established in 2021 by the International Agency for Research on Cancer (IARC), in collaboration with 20 research institutes worldwide. The overarching aim of OPICO is to develop the largest and most comprehensive international resource for investigating opioid use and its long‑term health effects.

OPICO harmonizes data from 30 sources, including prospective cohort studies, cancer registries, medication dispensing or prescription records, and electronic health records across the North America, Europe, and Australia. In total, OPICO includes nearly 1.2 million individuals, with detailed data on opioid use at baseline and over time, as well as chronic health conditions and key confounders, followed up for a median of 10 years.

Through this coordinated international effort, OPICO is enabling rigorous, globally comparable research to strengthen public health evidence and support the development of informed opioid prescribing guidelines and prevention strategies.