Association of opioid prescribing practices with chronic pain and benzodiazepine co-prescription: a primary care data linkage study

Background: Opioid prescribing is increasing worldwide with associated increases in misuse and other harms. We studied variations in national opioid prescription rates, indicators of prescribing quality, co-prescribing of benzodiazepines and relationship with pain severity in Scotland. Methods: Electronic linkages of opioid prescribing in Scotland were determined from: (i) national data from Information Services Division, NHS Scotland (2003-2012); and (ii) individual data from Generation Scotland: Scottish Family Health Study. Descriptive analyses were conducted on national data, multilevel modelling to examine factors associated with variations in prescribing rates. chi(2) tests examined associations between individual pain severity and opioid prescriptions. Results: The number of strong opioid prescriptions more than doubled from 474 385 in 2003 to 1 036 446 in 2012, and weak opioid prescribing increased from 3 261 547 to 4 852 583. In Scotland, 938 674 individuals were prescribed an opioid in 2012 (18% of the population). Patients in the most deprived areas were 3.5 times more likely to receive a strong opioid than patients in the least deprived. There was significant variation in prescribing rates between geographical areas, with much of this explained by deprivation. Of women aged 25-40 yr prescribed a strong opioid, 40% were also prescribed a benzodiazepine. There was significant association between pain severity and receipt of opioid prescription. Over 50% of people reporting severe pain were not prescribed an opioid analgesic. Conclusions: We found opioid prescribing in primary care to be common and increasing in Scotland, particularly for severe pain. Co-prescribing of opioids and benzodiazepines was common.