Research conducted by the Royal College of Surgeons in Ireland and Nuffield has revealed substantially different patterns in pain medication dispensing between Ireland and England over an eight-year period. The study analysed prescribing data from 2014 to 2022 and found that analgesia prescribing rates in Ireland were generally higher and increasing, whilst rates in England were lower and declining.

Understanding the Data Sources

The study examined monthly data on medicines prescribed and dispensed in primary care across both countries. For Ireland, the analysis focused on medicines prescribed through the General Medical Services (GMS) scheme, which covers approximately 32% of the population. The GMS scheme is means-tested, with higher eligibility thresholds for individuals aged 66 and over, meaning eligible persons tend to be older and from more socioeconomically disadvantaged backgrounds than the general population.

For England, data encompassed medicines prescribed through all general practices in the NHS, covering all individuals attending a GP practice. This fundamental difference in population coverage is crucial for understanding the study’s findings.

Diverging Patterns in Analgesia Prescribing

Between 2014 and 2022, the rate of analgesia prescribing in Ireland increased from 3388.6 to 4316.0 dispensings per 1000 GMS population. In contrast, England saw a decrease from 1824.0 to 1516.5 dispensings per 1000 NHS population.

Opioid Dispensing: The most striking differences emerged in opioid analgesia prescribing. In Ireland, opioid dispensings increased by 25%, rising from 978.7 to 1220.2 per 1000 population. England experienced the opposite trend, with opioid dispensings decreasing by 19%, from 720.5 to 584.6 per 1000 population.

Paracetamol: Paracetamol dispensing, including combination products, increased by 41% in Ireland (from 1295 to 1824 per 1000 population) but decreased by 34% in England (from 734 to 484 per 1000 population).

Systemic NSAIDs: Both countries saw reductions in systemic NSAID dispensing, though the magnitude differed considerably. Ireland experienced a 6% decrease (from 781 to 734 per 1000 population), whilst England saw a 35% decline (from 259 to 167 per 1000 population).

Specific Opioid Medications Show Varied Trends

The study examined individual opioid medications, revealing notable patterns in analgesia prescribing practices:

Codeine: Codeine remained the most commonly dispensed opioid in both countries, accounting for 50% of all opioid dispensing in Ireland by 2022 (up from 45% in 2014) and 48% in England. In Ireland, codeine dispensings increased from 439.05 to 613.83 per 1000 population, whilst in England they decreased from 347.13 to 299.95 per 1000 population.

Tapentadol: Tapentadol showed the largest relative increases in both countries. In Ireland, dispensing increased by 389% (from 13.99 to 68.45 per 1000 population), whilst in England it increased by 130% (from 1.14 to 2.63 per 1000 population). By 2022, the dispensing rate of tapentadol in Ireland was 26 times higher than in England.

Tramadol: Tramadol dispensing decreased in both countries, falling by 5% in Ireland (from 271.3 to 256.7 per 1000 population) and by 40% in England (from 139.54 to 83.90 per 1000 population). As a percentage of total opioid dispensing, tramadol decreased from 28% to 21% in Ireland and from 19% to 14% in England.

Morphine: Morphine dispensing increased by 28% in Ireland (from 29.01 to 37.27 per 1000 population) but showed minimal change in England, increasing by just 6% (from 71.30 to 75.33 per 1000 population).

Fentanyl: Fentanyl dispensing remained relatively stable in Ireland but decreased by 43% in England (from 21.26 to 12.08 per 1000 population).

Medications for Neuropathic Pain

Both countries experienced increases in analgesia prescribing for medications commonly used to treat neuropathic pain:

Pregabalin: In Ireland, pregabalin dispensing increased by 28% (from 309.31 to 395.62 per 1000 population). In England, dispensing increased by 78% (from 71.30 to 126.67 per 1000 population). Pregabalin was reclassified as a controlled drug in England in 2019, after which dispensing plateaued.

Gabapentin: Gabapentin dispensing nearly doubled in Ireland, increasing by 97% (from 54.58 to 107.71 per 1000 population). In England, dispensing increased by 26% (from 87.01 to 109.48 per 1000 population). Following reclassification as a controlled drug in 2019, gabapentin dispensing in England peaked in 2018 before decreasing and plateauing.

Low-dose Amitriptyline: Low-dose amitriptyline (10mg), typically prescribed for chronic pain rather than depression, showed substantial increases. In Ireland, dispensing increased by 194% (from 42.67 to 125.67 per 1000 population). In England, dispensing increased by 34% (from 123.53 to 166.00 per 1000 population).

Understanding the Disparities in Analgesia Prescribing

The researchers identified several factors that may explain the substantial differences between the two countries:

Population Characteristics: The GMS population in Ireland is older and more socioeconomically disadvantaged than the general population. Previous research has identified higher prevalence of pain among older adults and individuals from disadvantaged backgrounds. During the study period, the GMS population in Ireland decreased from 1,768,700 in 2014 to 1,568,379 in 2022, potentially indicating that the GMS population became comparatively more deprived.

To account for differences in deprivation, researchers analysed data from the most deprived third of clinical commissioning groups (CCGs) in England. This analysis found higher dispensing rates compared to the overall NHS population (2083.26 vs 1824.02 per 1000 in 2014 and 1934.72 vs 1516.54 in 2022), bringing them closer to Irish rates but still substantially lower.

Healthcare System Differences: England offers universal access to health services, including pain clinics and non-pharmacological interventions for pain management. NICE guidelines recommend exercise programmes, psychological therapy, acupuncture and electrical physical modalities as primary interventions for chronic pain. However, access to these treatments for GMS patients in Ireland is often limited.

Waiting Times: Waiting times in Ireland for GMS patients are considerable, particularly for orthopaedics. As of March 2024, over 63,000 individuals were awaiting orthopaedic outpatient appointments. Patients with severe degenerative-related chronic pain may wait several years for joint replacement surgery, potentially requiring strong analgesics during this period.

Prescribing Guidelines: Guidelines on analgesia prescribing vary between the two health systems. In November 2017, NHS England issued guidance on items which should not routinely be prescribed in primary care, specifically addressing oxycodone/naloxene combination products, paracetamol/tramadol combination products, immediate-release fentanyl and lidocaine plasters. Similar guidelines do not exist in Ireland.

The Clinical Context of Analgesia Prescribing

The study examined standard doses and oral morphine equivalents (OMEs) to account for differences in medication strength and quantity:

Daily Doses: In Ireland, the rate of defined daily doses (DDDs) of analgesics per 1000 GMS population per day increased from 116 in 2014 to 147.6 in 2022. Opioid DDDs increased from 33 to 40.3 per 1000 population per day. In England, DDDs per 1000 per day decreased from 97 to 80.6, with opioids decreasing from 39.1 to 31.9.

Oral Morphine Equivalents: In Ireland, the rate of OMEs dispensed per 1000 GMS population per day increased from 1409.8 to 1737.8. In England, the OME rate decreased from 1262.8 to 911.6. By 2022, the rate of OMEs was 1.91 times higher in Ireland than in England.

Cost Implications

After adjusting for exchange rate and purchasing power parity, cost rates for analgesia prescribing remained substantially higher in Ireland compared to England. In Ireland, the cost rate per 1000 population decreased by 19% during the study period, whilst in England it decreased by 49%. The adjusted rate ratio for costs in Ireland versus England was 3.98 in 2014, increasing to 6.52 in 2022.

This discrepancy is potentially driven by generally higher medication costs in Ireland and higher utilisation of branded drugs compared to England. Recent measures introduced in Ireland to reduce medication costs include generic substitution and the Preferred Drug Initiative, though neither specifically focus on analgesic medications.

Public Health Considerations

The study highlights the importance of understanding analgesia prescribing patterns in the context of pain management and public health:

Opioid-Related Harms: In England and Wales, opioid-related deaths increased from 8.4 per million people in 1993 to 43.8 in 2023, including steady increases in deaths related to tramadol and codeine. Opioid-related hospitalisations in England increased by 49% from 2008 to 2018. In Ireland, harms associated with prescription opioid misuse appeared to have remained relatively stable between 2010 and 2020.

Over-the-Counter Availability: Low-dose codeine products are sold over-the-counter in both countries. An analysis of over-the-counter codeine sales in 31 countries found that Ireland and England had the second and fourth highest rates of sales, respectively. However, the study only captured prescribed medications, meaning total codeine consumption may be underestimated.

Implications for Healthcare Policy

The research underscores the need for enhanced availability of non-pharmacological services and interventions to address pain, particularly in Ireland. The substantially higher rates of analgesia prescribing in Ireland compared to England appear too large to be fully explained by population differences alone.

The findings suggest several areas requiring attention:

• Improved access to non-pharmacological pain management interventions
• Reduced waiting times for procedures such as joint replacement surgery
• Enhanced guidelines for appropriate analgesia prescribing
• Better understanding of the drivers behind high-volume analgesic use
• Greater availability of pain clinics and specialist services

The study’s authors emphasise that whilst differences in the populations studied partially explain the disparities, further research using individual-level data is needed to analyse specific prescribing patterns, including long-term use, switching behaviours, and clinical indications for analgesic prescribing.

Source: dbrecoveryresources