Healthcare use by people who use illicit opioids (HUPIO): development of a cohort based on electronic primary care records in England (extended data)

This dataset includes:1. Search terms used to identify codes that may represent a history of illicit opioid use 2. Codelist for identifying people with a history of illicit opioid use 3. Age- and sex-distribution of patients by product and clinical codes 4. Number of patients currently in the cohort5. Age of patients at cohort entry6. Internal validation based on hospital admissions for opioid dependence