Pharmaceutical opioids utilisation by dose, formulation, and socioeconomic status in Queensland, Australia: a population study over 22 years.

Background Prescription opioids are a central aspect of pain management and as the prevalence of pain is increasing so is the rate of use of prescription opioids. Increased opioid prescriptions increases the risk of deaths and morbidity. Objective To (a) describe the 22-year trend of prescription opioid dispensing in Queensland, (b) examine the effect of opioid dose, formulation and socioeconomic status on the number of prescriptions dispensed. Design/setting Retrospective analysis of data from the Monitoring of Drugs of Dependence system of the Monitored Medicines Unit of Queensland Health, Australia. Participants Queensland residents (3.3 million) from 18 years old dispensed 18.8 million opioid prescriptions from January 1997 to December 2018. Results Opioid prescriptions dispensed annually increased to over two million in 2018 from about 150,000 prescriptions in 1997. The number of prescriptions for modified-release formulations dispensed annually was three times higher compared to the immediate-release formulations. Oxycodone accounted for over 60% of prescriptions for pharmaceutical opioids since 2013. There was an increase in the number of prescriptions dispensed as socioeconomic status decreased and modified-release opioid formulations positively affects the pattern of dispensing. The highest increase in number of prescriptions dispensed (for all opioids) was observed among the high socioeconomic status (IRR = 1.25, 95% CI 1.25, 1.26). The disparities in the annual number of prescriptions across dose categories are wider in the modified-release than the immediate-release formulations. Conclusion The dispensing of opioids increased significantly in Queensland. There was a positive relationship between the increased dispensing of opioids and locations of lower socioeconomic status.