Determining the impact of opioid policy on intended and unintended harms: a data linkage study

Study type

• Study type:
  Non-interventional study
• Scope of the study:
  Disease epidemiology

  Drug utilisation

Non-interventional study

• Non-interventional study design:
  Cohort

  Other
• Non-interventional study design, other:
  Case-crossover

Population studied

• Age groups:
  • Adolescents (12 to < 18 years)
  • Adults (18 to < 46 years)
  • Adults (46 to < 65 years)
  • Adults (65 to < 75 years)
  • Adults (75 to < 85 years)
  • Adults (85 years and over)
• Estimated number of subjects:
  60000

Study design details

• Main study objective:
  Using a linked dataset, this project aims to examine if changes to opioid prescribing policies have impacted prescription opioid-related harms.
• Outcomes:
  The main outcomes of interest are ED presentations and hospital admissions attributed to substance use (both opioid and non-opioid) or mental ill-health (e.g. suicide, self-harm, anxiety, depression). We focus on these outcomes as opioid and non-opioid-related substance use, mental health crises and suicide have all been demonstrated to be key outcomes related to changes in opioid prescribing.
• Data analysis plan:
  This is a population linked data study using data from general practice health records obtained from the Population Level Analysis and Reporting (POLAR) platform and linked with person-level data from three large hospital networks in Victoria, Australia. Interrupted time series (ITS) will be used to examine the impact of opioid policies on a range of harms including the incidence of presentations related to substance use (opioid and non-opioid), and mental ill-health among the primary care cohort. Group-based trajectory modelling and a case-crossover design will be used to further explore the impact of changes in opioid dosage and other covariates on opioid and non-opioid poisonings, and mental ill-health related presentations at the patient-level.