LAUSR

Background Studies of prescribing of opioid medication for chronic pain in the UK population show that it has increased sharply over the past 25 years. Although overall rates may have begun to decline recently, longer-term use and prescribing of ‘strong’ opioids continue to rise. Whilst analysis of data at a population level can tell us much about the use of these medications, an analysis at an individual level is needed to understand which patients, and how many, are at greatest risk from these potentially harmful drugs. Harms associated with these drugs are related to dose and length of use. The aim of this study was to develop a method to identify patients prescribed long-term, high doses of these drugs in the community and to assess the prevalence of such use. Methods Details of all opioid prescriptions issued over a four-month period were collected from two demographically dissimilar GP practices. A total of 22,841 patients were registered at the practices, 1488 (6.5%) of whom were prescribed opioids in the study period. Exhaustive examination of prescription data identified all patients who were prescribed oral morphine equivalent (ME) doses of 120 mg/day or more in the census period. An examination of the prescription histories of these patients indicated those who had been prescribed opioids at this level for a year or more. Results Every patient who met our criterion of ≥120 mg/day ME for a year or more was being prescribed that level as a single drug of morphine, oxycodone or fentanyl, irrespective of opioid polypharmacy. Across the two practices, 1.71/1000 patients were identified as long-term, high-dose users of opioid medication for chronic non-cancer pain. Prevalence was similar in the two practices. Unadjusted extrapolation suggests that there are over 100,000 similar patients in the UK. Conclusion This study provides a simple, reliable and practical means of identifying patients prescribed long-term high-dose opioid medication for chronic pain. These regimens are unlikely to provide additional pain relief but increase the risk of harm to patients. They have marked negative effects on day-to-day functioning and quality of life. Patients of interest can be identified simply through their use of three drugs as threshold doses and above. This can help in the further investigation of dysfunctional medication use; in establishing national and local prevalence; in monitoring service provision; and in identifying associated factors, such as social deprivation and regional variation.