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The opioids domain of the Atlas of Healthcare Variation gives an overview on the use of opioids, by district health board (DHB), to identify areas of wide variation. 

Update with 2014 and 2015 data

(Updated August 2016)

Key messages:

  • Strong opioid use continues to increase.
  • The level of variation between DHBs in strong opioid use has decreased from three-fold to two-fold.
  • Rates of strong and weak opioid dispensing are statistically higher in people of European/Other ethnicity, women and people aged 80 and over.
  • Almost half of those dispensed a strong opioid had a ‘trigger event’ in a public hospital in the week prior, suggesting these prescriptions are generated in hospital.
  • Oxycodone use continues to decrease, which is a positive finding, given the risks associated with this medicine.
  • Rates of fentanyl use are low, but are increasing and there is wide variation in use (more than 12-fold).

Key findings

The number of people dispensed a strong opioid continues to increase
  • A ‘strong’ opioid is one classed as step three of the World Health Organization (WHO) analgesic ladder. In New Zealand the following strong opioids are subsidised: fentanyl, methadone, morphine, oxycodone and pethidine.
  • Excluding people receiving methadone for opioid substitution treatment, in 2015, an average of 16.4/1000 people in New Zealand received a strong opioid. There was a two-fold variation between DHBs.
  • People identifying as European/Other ethnicity were dispensed a strong opioid 2–5 times more than other ethnic groups.
  • Use increased significantly with each age group; on average, 1 in 9 people aged 80+ received a strong opioid in 2015.
  • Women were dispensed significantly more strong opioids than men.
  • Thirteen percent of people receiving a strong opioid took the opioid for six or more weeks. Rates have remained steady since 2012.
Rates per 1000 of dispensing of strong opioid medicines, by age and ethnicity
Age (years) Māori Pacific peoples Asian European/Other
0–24 1.4 1.3 0.6 2.7
25–64 15.7 10.6 3.8 15.9
65–79 43.7 39.3 17.9 41.3
80+ 83.1 71.2 53.9 113.7
Total 10.1 7.9 3.9 20.5
Weak opioid use increases with age 
  • A ‘weak’ opioid is classed as step two of the WHO analgesic ladder. In New Zealand the following weak opioids are subsidised: tramadol, codeine and dihydrocodeine. Paracetamol with codeine was excluded as it contains a comparatively low dose of codeine.
  • In 2015, an average of 66/1000 people in New Zealand received a weak opioid. Use varied two-fold between DHBs.
  • People identifying as European/Other ethnicity received significantly more weak opioids, while Asian peoples received significantly fewer.
  • Use increased significantly with age; on average 1 in 7 people aged 80+ received a weak opioid in 2015.
  • As with strong opioids, women were dispensed significantly more weak opioids than men.
Morphine use has increased since 2011
  • In 2015, an average of 11/1000 people received morphine. Use varied two-fold between DHBs.
  • Of those dispensed a strong opioid in 2015, most received morphine.
  • The number of people dispensed morphine has significantly increased by 17,600 people since 2011, from 7.5 to 11 per 1000 people.
  • Of every 10 people given morphine, 1.2 took it for six or more weeks. 
Oxycodone use has significantly reduced since 2011
  • In 2015, an average of 5.4/1000 people received oxycodone. Compared with 2011 rates, this is a significant reduction of 7800 fewer people.
  • Use varied more than three-fold between DHBs.
  • Of every 10 people given oxycodone, 1.2 took it for six or more weeks. This rate has decreased significantly since 2012.
Rates of fentanyl use is increasing but varies widely
  • In 2015, an average of 1.7/1000 people received fentanyl. This was a significant increase from 2011 (0.8/1000). Use varied over 12-fold between DHBs.
  • Of those given fentanyl, 24 percent took it for six or more weeks.
Use of medication by site of residence | 65 and over (2014)

Further analysis was done comparing dispensing rates of three strong opioids according to where people live. Two groups were created – those aged 65 and over living in the community and those aged 65 and over living in a rest home. People in a rest home receiving a higher level of care, such as rest-home hospital, dementia or psycho-geriatric, were excluded from this analysis to make the groups more comparable.

As the figure below shows, fentanyl and morphine use are increasing faster in those living in a rest home than in those living in the community. Oxycodone use is reducing at a similar rate in both rest homes and the community.

Graph showing dispensing of strong opioids comparing site of residence

Almost half of those dispensed a strong opioid had a public hospital ‘trigger event’
  • Of every 10 people dispensed a strong opioid, 4.7 attended a public hospital as an inpatient or outpatient in the week prior.
  • Younger people were more likely to have a public hospital event (7/10) compared with older – 3.7/10 of those aged 80+. Several factors are likely to have contributed to this. 


The Institute for Healthcare Improvement (IHI) classes opioids as one of four groups of medicines (along with anticoagulants, insulin and sedatives) that can cause harm to patients, even when used as intended.

Opioid analgesia is the primary intervention for managing pain in hospital patients. Opioids are also considered effective treatment for severe pain in palliative care[1]. In the non-specialist setting, the National Institute for Health and Care Excellence (NICE)[2] recommends opioids should not be used for neuropathic pain without specialist assessment. A recent review noted increases in both opioid use for back pain and other chronic musculoskeletal pain conditions, and in prescription opioid addiction and fatal overdose[3].

Despite the increasing use of chronic opioid therapy, there is limited evidence that opioids are effective for treating chronic non-cancer pain in the long term. A 2013 Cochrane review concluded that long-term use of opioids should be undertaken with extreme caution and should consider the potential for serious adverse effects and complications[4]. Harms associated with opioid therapy include opioid tolerance, opioid-induced hyperalgesia[5], iatrogenic addiction and dependency, drug diversion and aberrant drug-related behaviours[6]. In addition, a strong relationship between severe dependence on opioids and other substance use and mental health disorders has been observed[7].

It is recommended that health practitioners considering prescribing opioids for chronic non-malignant pain carefully undertake a benefit-to-harm evaluation to ensure that opioid therapy is the best option. The evaluation should include taking a history, undertaking a physical examination and performing a full diagnosis before starting opioid therapy and evaluation should be ongoing for the duration of the therapy[8]

Data sources and method

Data for this Atlas domain was drawn from the Pharmaceutical Collection, which contains claim and payment information from community pharmacists for subsidised dispensing. This collection does not allow for analysis of patients’ condition or the effectiveness of dose provided. This means it was not possible to assess the appropriateness or otherwise of prescribing. Unsubsidised dispensing is not included in this analysis; nor does it indicate if people took the medicine.

The methodology is provided here.

Note this analysis focuses on the number of people dispensed opioids, not on the number of prescriptions of these medicines. We have used this approach because interpreting what the number of dispensed prescriptions might mean is complicated by differences in prescribing frequency, formulation and dose, and if the medicine is to be taken ‘as needed’ or at regular times. We recommend further local analysis on the people receiving these medicines that accounts for these factors and the person’s clinical condition.

What questions might these data prompt?
  • Why do some DHBs have consistently lower or higher rates than the national mean?
  • How do DHBs with similar populations compare?
  • What is your DHB’s trends for opioid prescribing in ARC?
  • What is driving the prescribing of morphine and fentanyl in the elderly?
  • What is the effect of a DHB’s access to specialist pain services on the use of opioids?
  • What is the effect of access to palliative care services?
  • What impact might access to non-pharmacologic pain management have on these rates?
  • What tools and skills do primary care providers to have to manage chronic non-cancer pain?
  • Why are there marked ethnic differences in the use of opioids? Is this the result of higher use in older people or might it reflect other differences such as different cultural expressions of pain and different ways of coping with pain?
  • What other combinations of medicines are people receiving strong opioids for six or more weeks also receiving? Additional analysis showed almost half of those on strong opioids (4.6/10) received a benzodiazepine in the same period. 
  • What is the extent of polypharmacy in older patients who are using opioids?
  • What is the falls rate of older people in your DHB who are using opioids compared to those who are not?
  • What are the regular pain management medicines used for older people who have had a fall?

Find My Patients query and clinical audit template

Find My Patients allows you to run three different queries using your patient management system (PMS) to identify patients who received a strong opioid:

  1. for at least a month and
  2. have diagnosed chronic obstructive pulmonary disease (COPD) (strong opioids are either contraindicated or have a caution) and
  3. have no co-prescribed stimulant laxative to deal with the common side effect of constipation.

You can also use the query as part of a clinical audit. GPs who complete the audit are entitled to Maintenance of Professional Standards (MOPS) credits from the Royal New Zealand College of General Practitioners (RNZCGP). Download information and instructions for using the opioids query and clinical audit.

Further information

A summary of new chronic pain indicator suites for New Zealand clinicians, by Dr R Perera and Dr H Moriarty, is available here. The full report is here.

Recommended reading


  1. BPAC. 2012. Strong opioids for pain management in adults in palliative care. Best Practice Journal 49. URL: www.bpac.org.nz/bpj/2012/december/docs/bpj_49_opioids_pages_8-17.pdf.
  2. NICE. 2013. Do not use morphine to treat neuropathic pain in non-specialist settings, unless advised by a specialist to do so. URL: www.nice.org.uk/donotdo/do-not-use-morphine-to-treat-neuropathic-pain-in-nonspecialist-settingsunless-advised-by-a-specialist-to-do-so (accessed 20 June 2016).
  3. Korff M. 2013. Long-term Use of Opioids for Complex Chronic Pain. Best Pract Res Clin Rheumatol 27(5): 663–72.
  4. Chaparro LE, Furlan AD, Deshpande A, Mailis-Gagnon A, Atlas S, Turk DC. Opioids compared to placebo or other treatments for chronic low-back pain. Cochrane Database of Systematic Reviews 2013, Issue 8. Art. No: CD004959. DOI: 10.1002/14651858.CD004959.pub4.
  5. Chen L, Vo T, Seefeld L et al. Lack of correlation between opioid dose adjustment and pain score change in a group of chronic pain patients. 2013. J Pain. Apr;14(4):384-92. 
  6. Sullivan MD, Von Korff M, Banta-Green C et al. 2010. Problems and concerns of patients receiving chronic opioid therapy for chronic non-cancer pain. J Pain. May;149(2):345-53.
  7. The Royal Australasian College of Physicians, Prescription Opioid Policy: Improving management of chronic non-malignant pain and prevention of problems associated with prescription opioid use, Sydney 2009.
  8. Chou R, Fanciullo GJ, Fine PG et al; American Pain Society-American Academy of Pain Medicine Opioids Guidelines Panel. Clinical guidelines for the use of chronic opioid therapy in chronic noncancer pain.

Last updated 17/10/2016