Impact of Removing Nonprescription Codeine in Australia: Protocol for a Prospective Cohort Study

Abstract

Background On February 1, 2018, Australia rescheduled codeine to a prescription-only medication. Many concerns were associated with this change, including increased financial costs, reduced service accessibility, the potential for poorer pain management, and a decline in physical and mental health if codeine could not be accessed. In the research literature, there is limited knowledge about the long-term consequences of rescheduling pharmaceutical opioids and, as Australia has followed many countries in implementing a restriction on codeine, further study of these consequences is critical. Objective The goal of this study was to examine the impact of rescheduling codeine from an over-the-counter (OTC) product to a prescription-only medicine on the primary measures of codeine use and dependence in a prospective cohort of people who are frequent consumers of OTC codeine. Secondary measures included pain and self-efficacy, health service use, and mental health. Methods The Codeine Cohort study aimed to recruit 300 participants in Australia who regularly (at least a few times per week for the past 6 months) used OTC codeine. Using an online survey, participants were followed up at three time points (February 2018, June 2018, and February 2019) after codeine was rescheduled. Results All four waves of data collection are complete, with the final round of data collection finalized in August 2019. Data analyses are yet to be completed. Information on demographics, codeine use and dependence, physical and mental health, medication use, and health service use will be analyzed using mixed models. Conclusions Results of this study will provide insight into the effectiveness of regulatory restriction in curtailing nonmedical use of and harms associated with codeine. Additionally, results will explore positive and negative outcomes of codeine rescheduling for individual patients, which informs health professionals who support patients who use codeine and further community education. International Registered Report Identifier (IRRID) DERR1-10.2196/15540