The pain divide

Chronic pain is a serious and growing worldwide problem, and the burden it places on our society is increasing.

To manage the symptoms associated with chronic pain there is heavy reliance on the use of opioid analgesics, although there are limited studies to support their long-term effectiveness. In addition, prolonged use of opioids can also have serious and sometimes life-threatening adverse consequences, such as constipation and respiratory failure.

Despite these well-acknowledged negative effects, the prescribing of opioid analgesics continues to increase at a significant and worrying rate. Indeed, figures from the UK show that in 2014 there was around 23 million prescriptions written for opioid analgesics, at a cost of around £322 million. Given this increased use (and the well-established problems associated with efficacy, tolerance, dependence and adverse effects) the inappropriate prescribing – and misuse – of opioid analgesics is becoming a significant public health concern. This problem is mirrored in other countries, such as the US, where the death rate from opioid mis-use has, in the last 15 years, quadrupled – giving rise to the so-called ‘opioid epidemic’.

Are we in the UK heading the same way? Based on discussions within our Durham University Pain Special Interest Group and a public discussion forum held in 2017 in the North East, funded by a British Pharmacological Society Ambassador grant, the issues of local opioid prescriptions and pain management were highlighted and this study was initiated.

There is significant geographical variation in opioid prescribing in the UK– with more people in the North of England prescribed opioids – at a greater cost – compared to the rest of England. For example, the North of England accounts for approximately 33% of the total costs of analgesics, compared to London, which accounts for around 8%. It was not clear before our study, however, if this variation was related to inappropriate prescribing or the varying health need of the population (i.e. more people in the North of England have pain, hence the prescribing of opioids is higher).

It is well documented, though, that mortality and morbidity rates are higher in the North of England, particularly in the North East region compared to the rest of England: an observation coined the North-South health divide. Given the public health concerns associated with the inappropriate and long-term use of opioid analgesics, it was vitally important then to explore whether the prescribing of opioid analgesics across England reflects inequalities in the health needs of the population or if there an issue related to inappropriate prescribing or utilisation.

Chronic pain is defined as pain that extends beyond the expected period of healing, usually 3-6 months since onset. We are the first to examine the geographical inequalities in chronic pain prevalence, pain intensity, and opioid utilisation in England. As well as this, we were the first to examine the association between chronic pain prevalence and pain intensity and opioid utilisation. We have identified two key findings that will be of importance to healthcare practitioners and policy makers:

1. There are geographical variations in chronic pain prevalence, pain intensity, and opioid utilisation across the English regions – with evidence of a ‘pain-divide’ with people in the North East of England more likely to have chronic pain.
2. Opioid utilisation was significantly, and positively, associated with pain intensity.

Our paper is timely, and shows that, in England, the prescribing of opioid analgesics is largely driven by health need (ie pain); thus, to develop strategies going forward, and to avoid a potential ‘opioid epidemic’, it is important that consideration is given to other ways of managing chronic pain, without the use of opioid analgesics. Given our findings, more needs to be done – at a national level – to support prescribers to manage people who have chronic pain, without the need to initiate opioid analgesics, perhaps using more non-pharmacological pain management strategies.

Another important consideration highlighted by our study is the growing use of gabapentin in the UK. Gabapentin is widely considered to be a non-addictive alternative to opioids for chronic pain prescribed to all age groups. However, it is not only prescribed for pain relief but also offered to treat other conditions such as sleep and affective disorders. As a result, some people are taking opioids for pain relief and gabapentin for other medical conditions.

Furthermore, the abuse potential of gabapentin is well documented, as an agent highly sought after for use in potentiating the effects of opioids. Reclassification of gabapentin as a controlled substance and the need for more care in prescribing both gabapentin and opioids together also needs careful consideration going forward.

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