Opioid Use After Injury

S Goyal*, Dr R Griffiths**
*Lead Pharmaceutical Advisor
**Senior Medical Advisor
Corporate Clinical Advice, Clinical Services Directorate, Accident Compensation Corporation, New Zealand

Introduction: Internationally, workers’ compensation agencies have identified a correlation between the increased prescribing of opioids and an increase in resultant harms; notably addiction, falls, mental health issues, abnormal pain responses and death by overdose. Whilst pharmaceutical review of ACC client files demonstrated extensive use of opioids for pain relief, the prevalence and impact of this on rehabilitation and function was unclear.

Aim: To better understand patterns of opioid use by ACC clients after injury and identify factors that might increase the likelihood of opioid use.

Methodology: Data captured through the Ministry of Health’s Pharm Data Warehouse was matched with ACC claims data over the period 2009 to 2013. Patient identifiers were removed and the data was analysed to look at patterns of opioid use, demographic influencers, association with rehabilitation entitlements and probability of continued use, post-injury.

Results: Between 2009 and 2013, the prescribing of opioids increased by 42%. The subsidising of Tramadol in 2010 is thought to have been a factor in this.  Gender, age, ethnicity and need for entitlements determined prevalence of use; whereas co-morbidities, injury type, age and circumstances of injury (i.e. treatment injury or motor vehicle accidents) influenced the type and duration of opioid use.

Whilst 78% of claims involved the prescribing of weak opioids, the elderly (≥75yrs) were more likely to use strong opioids for a prolonged period (>12 weeks). This was usually related to the management of fractures and soft tissue injuries.

Conclusion: The data highlights a need for further research into opioid prescribing patterns in the elderly population; and whether the use of strong opioids demonstrably increases the risk of harm for this age group. This could be explored as part of the Falls Prevention and Health of the Older Persons Strategies.