Main Findings
The aim of this overview was to summarise the evidence and critically assess the quality of SRs that are relevant to the ten priorities of the Levy consensus (Levy et al., 2021) and the ten priorities of the Forget consensus (Forget et al., 2022). This overview has identified a total of 12 SRs, which related to only six out of the ten priorities of the Levy consensus (Levy et al., 2021) and two of the ten priorities of the Forget consensus (Forget et al., 2022). This means that a total of 12 priorities from both consensuses do not have evidence that could be identified through the methods of this overview that either supports or opposes them. Thus, we have identified a gap in research that requires further attention and efforts to fill to enhance stewardship of opioid prescribing for acute postoperative pain.
The SRs that were identified were generally of low quality according to the AMSTAR 2 checklist (seven were critically low, two were low, one was high and two could not be fully appraised). Hence, further research is required to produce evidence of a higher quality to support the consensuses and pave the way for future safer opioid prescribing. The AMSTAR 2 tool was developed in 2017 as an upgraded version of the original AMSTAR tool. It is a well-used valid and reliable appraisal tool (Lorenz et al., 2019).
Implications of Findings Within Current Literature
The prescribing of opioids for acute postoperative pain remains a highly controversial topic. The two consensus statements provide very promising progress for the development of national protocols for the safe prescribing and stewardship of postoperative opioids. With regards to these consensus statements,
With regards to priority 1 of the Levy consensus (“all patients undergoing surgery should be assumed to be at risk of developing persistent postoperative opioid use and opioid-induced ventilatory impairment and may need interventions to mitigate those risks”), the SR by Lawal et al. (2020) provided evidence to support this statement. They concluded that strategies, such as proactively screening for at-risk individuals, should be priorities to reduce the substantial burden that persistent opioid use after surgery elicits on public health. Lawal et al. reported that preoperative use of opioids and cocaine and the presence of comorbid pain conditions before surgery were found to have the strongest associations with persistent opioid use after surgery. These modifiable risk factors could be included in a comprehensive approach to identify patients at higher risk of persistent opioid use and opioid-induced ventilatory impairment. However, it should be noted that this evidence was of critically low quality according to the AMSTAR 2 checklist.
Priority 2 of the Levy consensus (“Consider optimising management of pre-operative pain and psychological risk-factors before surgery, including weaning of opioids where possible. Ensure realistic expectations of postoperative pain control, both in hospital and after discharge”) has three included SRs that provide evidence to support it. First of all, the SR by Horn et al. (2020) concluded that addressing the psychological needs of patients through preoperative education can decrease acute postoperative pain, and therefore decrease the need for opioid consumption. Additionally, the SR by Powell et al. (2016) found evidence that suggested preoperative psychological preparation may be beneficial for various outcomes, such as postoperative pain, behavioural recovery, negative affect and length of stay in hospital. However, the strength of evidence they found was insufficient, thus they recommended that further research is required to support this. Finally, the SR by Sobol-Kwapinska et al. (2016) analysed the relations between presurgical psychological factors and acute postoperative pain. They identified numerous psychological variables that could be considered for optimising preoperative psychological risk factors before surgery, as recommended by Levy et al. (2020). The quality of evidence according to the AMSTAR 2 checklist was noted to be critically low for the SRs by Horn et al. (2020) and Sobol-Kwapinska et al. (2016), but was high for the Powell et al. (2016) SR.
Baamer et al. (2022) provided evidence for priority 3 of the Levy consensus (“provision of opioid analgesia should be guided by functional outcomes, rather than unidimensional pain scores alone”) by challenging the validity and reliability of unidimensional tools to quantify acute postoperative pain. They also discovered that studies on functional outcomes assessment tools were scarce, and therefore proposed more research is necessary to assess the validity and reliability of such tools. The quality of this SR was low, according to the AMSTAR 2 tool. Thus, future research of a higher quality could be beneficial to further support priority 3 of the Levy consensus.
Priority 4 of the Levy consensus (“multimodal analgesia should be optimised and patients educated about the use of non-pharmacological and non-opioid analgesia to reduce the amount and duration of opioids required to restore function”) was supported through evidence from the SR by Martinez et al. (2017). This paper concluded that a multimodal regimen of non-opioid analgesics was superior to solitary use of a single non-opioid analgesia in reducing acute postoperative pain and morphine consumption. The supplementary material of this SR was unavailable, resulting in full quality appraisal being unachievable. More research could be done to further assess multimodal analgesic regimens to increase the validity of this recommendation from Levy et al. (2020).
There are two SRs found through the methodology of this overview that provide evidence for the 6th priority of the Levy consensus (“a patient-centred approach should be used to limit the number of tablets and the duration of usual discharge opioid prescriptions, typically to less than a week”). Arwi and Schug (2020) suggest that the current opioid prescribing practices could be improved. The studies they analysed showed that discharge opioids contribute to prolonged opioid use. However, more high-quality research with comparable outcomes is needed. Additionally, the SR by Feinberg et al. (2018) reported that surgical patients are using substantially less opioid than prescribed, leading to excess opioids that may be used inappropriately by patients or others. The authors agreed that strategies and clinical practice guidelines are needed to better educate prescribers and help standardise postoperative opioid prescriptions. It should be noted that both these SRs were of critically low quality according to the AMSTAR 2 tool. It would be beneficial for research of a higher quality be carried out to further support the Levy consensus.
The 10th priority of the Levy consensus (“patients should be advised on safe storage and disposal of unused opioids and directed to avoid opioid diversion to other individuals (e.g. sharing with friends and family)”) was also supported by the Arwi and Schug (2020) SR. This paper reported that a lack of patient education regarding safe storage and disposal of opioids contributes to the increasing rate of opioid misuse, diversion and unintended persistent opioid use. However, the authors recommend that more high-quality research is needed on this topic. The SR by Bicket et al. (2017) provides further evidence for the 10th priority. This paper concluded that postoperative opioid prescriptions often go unused, unlocked and undisposed, leading to a reservoir of opioids that contribute to the non-medical use of these products. Although both these SRs are of critically low quality according to the AMSTAR 2 checklist, they still provide important evidence that supports the 10th priority of the Levy consensus.
The SR by Lamplot et al. (2021) provides further evidence for priority 10 of the Levy consensus. They found that opioids are overprescribed for acute postoperative pain, and baseline rates of surplus opioid disposal are low. Furthermore, their results showed that drug disposal kits or bags help to significantly increase these rates. Due to the supplementary material being unavailable, we could not fully assess the quality of this SR. However, it provides valuable evidence for future strategies to increase the safe disposal of unused opioids.
With regards to the Forget consensus, the 1st priority (“the presence of a Pain Management, Analgesia or Opioid Stewardship Steering Committee, with multidisciplinary representation from Key Stakeholders is a priority in the context of acute pain, especially in the hospital”) has one included SR that provides supporting evidence (Wetzel et al., 2018). Their results showed evidence that clinician-mediated and organisation-level interventions are effective at reducing postoperative opioid prescribing. The quality of this SR was critically low. However, it provides useful evidence to aid the development of an evidence-based clinical practice guidelines.
Finally, Albrecht et al. (2019) found that there is overall low certainty of evidence that high-dose intraoperative opioids in patients under general anaesthesia increases pain scores and contributes to hyperalgesia in the postoperative period when compared to low-dose regimen. However, they proposed that additional robust methodology trials could better define the impact of each opioid regime on hospital and health-system recourses. This agrees with priority 4 of the Forget consensus (“policies should be developed providing guidelines on maximum doses and duration of treatment for high-risk medications such as opioids and high-risk combinations”) by suggesting more trials should be undertaken in order to help develop such policies. The quality of the Albrecht et al. (2019) SR was low according to the AMSTAR 2 checklist.
Implications of Findings for Future Research
The number of drug-related deaths has vastly risen over the past few decades in the UK. According to the National Drug-Related Deaths Database (NDRDD) for Scotland, there were 1,209 deaths in 2018 that were drug related in Scotland. Opioids were implicated in 77% of these deaths (Public Health Scotland, 2022). This is a significant increase from 2017, when there were 867 drug-related deaths in Scotland. In England and Wales, there were 3,756 drug-related deaths in 2018, a 16% increase from 2017 (Office for National Statistics, 2021). The rise in drug-related deaths is thought to be due to the increased availability and misuse of prescription and illicit opioids due to irrational prescribing, amongst other factors. There are concerns that the UK is closely following the trends of the devastating opioid epidemic seen in the USA. A solution to the contributing factor of liberal opioid prescribing for acute postoperative pain could be the implementation of national guidance and protocols.
The Levy and Forget consensuses provide a strong framework for such protocols (Levy et al., 2020; Forget et al., 2022). They are predominantly expert opinion based. Historically, medicine was based on the consensus of experts and their opinions on best practices. Though expert opinion is a highly regarded and useful method of gathering information, it is more valid when used concomitant with evidence-based literature for the creation of healthcare policies and protocols (Tonelli, 1999). Further research is required to provide evidence of a higher quality to support these consensus statements.
Strengths & Limitations
This overview included SRs of varying settings that covered a range of topics regarding rational opioid prescribing, enabling the concise evaluation and summarisation of literature related to the ten priorities of the Levy consensus (Levy et al. 2021) and the ten priorities of the Forget consensus (Forget et al., 2022). It therefore offers valuable insight into the evidence behind the two consensuses that are predominantly based on expert opinion. Furthermore, this overview was conducted in accordance with the Cochrane Handbook for the Systematic Review of Interventions (Pollock et al., 2022), which is well-known and well-used guidance, thus increasing reliability.
There are several limitations of this overview. Firstly, there was one SR that could not be accessed for full-text analysis which may have offered valuable evidence (Zorrilla-Vaca et al., 2022). Additionally, the supplementary material of three included SRs was not available, despite requesting access from the authors, resulting in full quality appraisals being incomplete (Lamplot et al., 2021; Martinez et al., 2017; Wetzel et al., 2018).
There was significant heterogeneity amongst the SRs regarding interventions, outcome measures, and quality evaluation method, with only four out of the 12 included SRs including meta-analysis. This meant that the SRs were not comparable. However, they provided valuable evidence for the aim of this overview.
Finally, another limitation of this overview is that the included papers were from a wide range of countries. Though this may provide useful information that could shape future rational opioid prescribing protocols, it may not be applicable to UK guidance.