Determining the Impact of Opioid Policy on Substance Use and Mental Health–Related Harms: Protocol for a Data Linkage Study (Preprint)

Abstract

UNSTRUCTURED Introduction Increasing harms related to prescription opioids over the past decade has led to the introduction of a range of key national and state policy initiatives across Australia. However, similar opioid policies internationally have had mixed outcomes, including unintended adverse consequences. There is little real-world evidence on how these policy levers work in Australia. Using a linked dataset, this project aims to examine if changes to opioid prescribing policies have impacted prescription opioid-related harms. Method and analyses 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. Ethics and dissemination Ethics approval was obtained from the Monash University Human Research Ethics Committee (ID 76744), Monash Health (RES-22-0000-026A), Peninsula Health (SSA/76744/PH-2022), and Eastern Health (S22-032-76744). Dissemination will occur by engaging stakeholders through reference groups and steering committees, as well as the production of research translation resources in parallel with peer-reviewed publications and conference presentations. Protocol registration details EU PAS Register (EUPAS104005)