Trends in Opioid Prescribing and Associated Resource Utilisation in Wales (TOPAS)

Exploring the overall use of opioids in the Welsh population and examining the impact of existing opioid prescribing patterns and the potential benefits of change.

Mrs Emma Davies, University of Swansea

Pain is generally defined as ‘an unpleasant sensory and emotional experience, associated with actual or potential tissue damage, or is described in such terms’. Chronic pain (CP) is accepted to be pain that has persisted for longer than three months and can be more accurately described as chronic, non-malignant pain (CNMP) or chronic non-cancer pain (CNCP), which helps to further differentiate it from pain associated with end-of-life morbidities, tumours or chemotherapy.

People living with CP will commonly have comorbidities such as sleep disturbance, anxiety and depression in addition to physical debilitation. Severe CP also adversely affects employment, relationships and people’s general health, for example daily back pain is associated with a higher incidence of coronary events. The complex interplay of bio-psychosocial factors results in CP causing a reduction in the quality of life of sufferers more than almost any other condition.  The high economic burden of CP in addition to poor quality of life has resulted in increasing attention being paid to its treatment over the last 10 years.  In Wales as in the rest of the UK, it is estimated that moderate to severe chronic pain likely affects around 13% of the population.

The use of opioids to treat pain has been established for hundreds of years and commonly accepted for the treatment of cancer and acute pain e.g. pain associated with trauma or surgery. Over more recent times, the use of opioids in the treatment of CP has increased. It is thought that opioids are likely to have less effect over time periods longer than 12 weeks and beyond certain doses the harms of continuation outweigh any therapeutic benefits. Concerns over the risk of dependence, tolerance and addiction have also been raised.

Despite this, over the last 10 to 15 year period, Wales has seen an increase in analgesic prescribing, which fits with general trends in the UK, Europe and the United States. In the UK, a doubling of opioid prescriptions was seen in the five-year period to 2011. Although the exact reasons for this trend have still to be fully elucidated more recent studies have demonstrated the increase to be associated with use in CP.

Patients’ adherence to opioids, the incidence of adverse-effects, risks of dependence and addiction and the impact on patients’ general health are not clearly defined in a Welsh or UK-wide population.

The current study attempts to begin to address the overall use of opioids in the Welsh population. The effectiveness and safety of long-term opioid use in the management of chronic pain will be explored as well as any association with differences in other health care utilisation or clinical morbidity in those receiving opioids for CP compared to those who do not.

The research will utilise datasets from the Secured Anonymised Information Linkage (SAIL) databank. SAIL is a Wales-wide research resource, which, links data from a large number of sources including; the Office of National Statistics, General Practice, Hospital outpatient and inpatient interactions and national screening programmes.  The databank provides data from over 70% of General Practices in Wales, which enables the data of over 2 million Welsh residents to be scrutinised as part of this research.

The second part of this study will be to develop an economic evaluation (cost of illness) to examine the impact of existing opioid prescribing patterns and potential benefits of change.

This project was awarded funding in 2016 and is due to run from January 2017 to March 2018.