Summary
Aim
The objective of this research was to develop a statistical methodology for identifying areas with aberrantly high supply levels of 80mg oxycodone controlled-release (CR) tablets, a prescription medicine that is currently a target for illicit diversion in Australia. The intention in developing this methodology was to provide assistance to the Pharmaceutical Services unit of the New South Wales Department of Health in monitoring supply and prescribing of high-strength prescription opioids.
Method
Statistical analysis focused on modelling variations across New South Wales (from 2006 to 2009) in wholesale supply rates of 80mg oxycodone CR tablets while controlling for relevant demographic and public health characteristics of each area.
Results
This analysis identified a number of Local Government Areas with supply levels of 80mg oxycodone CR tablets that were significantly higher than that predicted by the statistical model. In contrast to analysis of raw unadjusted supply counts of this medicine, which were highest in areas with large populations, statistical modelling identified mainly regional areas as those with unexpectedly high supply rates of 80mg oxycodone CR tablets.
Conclusion
The current findings highlight the importance of controlling for relevant population level characteristics related to indications for opioid prescribing when evaluating trends in supply of these medicines.