Some personal reflections on AAA guideline development with NICE

The development of the NICE guidance on the management Abdominal Aortic Aneurysm [AAA] has been a long, drawn out and difficult process. Publication of the final guidance (in Spring 2020) was overshadowed by the immediate (and ongoing) crisis created by the COVID pandemic which meant the revised recommendations did not get the scrutiny they deserved. While editorial comment was made about the surprising nature of NICE’s U-turn, the opportunity for wider debate and discussion has necessarily been lost.

My colleagues on the NICE AAA Guideline Development Committee [GDC] have recently published our (rejected) final recommendations on the repair of unruptured AAA. These were revised from the draft guideline after taking into account stakeholder feedback and NICE’s view on implementation but they were unacceptable to NICE. The basis for this was not made clear and the process by which NICE derived the recommendations it eventually published remains remarkably opaque.

The purpose of this blog post is to provide a personal perspective on my involvement in the guidance development process and to offer some suggestions for a way forward.

Since I was appointed to the AAA GDC, and particularly since the publication of the draft guidance in 2018, my involvement with NICE has been a significant professional and personal challenge. By and large (and with a couple of notable exceptions) I have not been subjected to the opprobrium that some of my colleagues on the committee have had to deal with but the behaviour of NICE’s senior management has left me with a deep sense of frustration, even anger at work taken for granted or ignored and for opportunities missed.

The gulf between the evidence base for the elective repair of unruptured AAA and current UK (and international) practice created a problem for NICE which was always going to result in difficult guideline implementation and professional acceptance. The complete proscription of standard EVAR in the draft guidance was a substantial shock to the vascular surgery and vascular radiology community and resulted in much tension and professional anxiety. This was evident in the stakeholder feedback received, which prompted a thoroughgoing review of the draft recommendations.

The health economic argument against EVAR for people fit for open repair is undeniable and I was (and remain) entirely content with the recommendation that EVAR not be offered to this group (whether you agree depends largely on whether you think cost-effectiveness is a reasonable basis for limiting access to an intervention). However, for patients unfit for open repair, my personal view was that there were cogent arguments for changes to the draft. In particular I had concerns about the generalisability of the randomised data to the whole of an almost certainly heterogenous population, and the difficulty applying population data to individuals in whom the alternative was no-repair. However, actually formulating revised recommendations incorporating these arguments was extremely difficult and I was unable to persuade anyone else in the GDC that my clumsy suggestions for rewording were an improvement. Ultimately, my GDC colleagues convinced me that minor revisions to the draft we made were reasonable and I was happy to accept cabinet responsibility for them. 

However, NICE were unwilling to publish the revised recommendations on repair of unruptured AAA, and an impasse was reached in spring 2019. To resolve this, over the summer of 2019, the GDC made considerable further efforts to revise them into a format acceptable to NICE’s senior management, and incorporating the themes raised by stakeholders and NICE’s implementation concerns. These are the recommendations the GDC has recently published and I think they are excellent. They have the unanimous support of the whole GDC, with no dissenting voices. 

During this time however (summer 2019 onwards), NICE abandoned and then (apparently deliberately) sidelined its GDC. One can argue the extent to which this behaviour failed the public in producing suboptimal recommendations on elective AAA repair. But NICE certainly failed in its duty of care to the committee members who received no support and only cursory communication and explanation. NICE simply asserted its right to editorial control over the recommendations it publishes – it has never previously exercised this right. It is astonishing NICE did not make more effort to engage with its GDC over 2019 to find a mutually acceptable set of recommendations. I am left with the sense that I, and the other GDC members, were deemed irresponsible and uncompromising absolutists when nothing could be further from the truth: despite NICE’s disengagement, we made huge efforts to create recommendations that were consistent with the evidence base, stakeholder comment and the published philosophical and ethical frameworks within which NICE requires its guidance to be developed.

I am also left with a sense that there has been a missed opportunity to influence repair strategies for unruptured AAA. The final guidance NICE published on this is bland and anodyne to the point of being meaningless. The cynic in me thinks this is deliberate: recommendations that don’t recommend anything allow practice to continue without amendment or cultural shift. Perhaps this is a convenient outcome for those to whom NICE seems to have turned, once it abandoned its GDC.

For example, NICE’s final (published) recommendation about repair for people unfit for open surgery: 

1.5.5 Consider EVAR or conservative management for people with unruptured AAAs meeting the criteria in recommendation 1.5.1 who have anaesthetic risks and/or medical comorbidities that would contraindicate open surgical repair.

How should a clinician consider this? What evidence and perspective should they bear in mind when making a decision with the patient? What information should the patient be offered? Does this recommendation contain anything that will help vascular specialists amend their practice to mitigate the marked regional variation in the management of unruptured AAA in the UK (variation that surely cannot be explained by case-mix)? While there is some evidence that the draft guidance has resulted in a small increase in the proportion of AAAs repaired with open surgery, whether this endures remains to be seen and there is nothing in the guideline to lock it in.

These concerns were not just mine. Ultimately the whole GDC was in agreement (again, with no dissenting voices) that NICE’s published recommendations about repair of unruptured AAAs neither reflect the evidence nor (even) NICE’s own narrative accompanying the recommendations. Given the GDC’s professional and lay diversity, this unanimity is striking. We all agonised over the decisions we made, but all independently reached the same conclusion. This was not some kind of bunkered groupthink.

Despite all this, there are some significant positives to be taken from my experience with NICE. even if I remain dissatisfied with the process and aspects of the eventual outcome. I enjoyed meeting colleagues I would otherwise not have met, and in particular I enjoyed the careful and academic consideration of the evidence base and the challenging of some of my preconceptions. NICE’s technical teams and information specialists are impressive and the clarity and precision they brought to committee discussions was very enlightening. Obviously I now have a valuable understanding of how NICE develops guidance and some of the compromises involved.

My experience also prompted a hitherto unknown interest in health economics and in particular the ethics associated with using this in decision making about health and healthcare interventions. What do we mean by need? How do we balance choice, affordability, cost effectiveness and equity? When demand in healthcare is substantially supplier driven, how do we prevent market failure? What value judgements do we make or need to make when allocating resource? These are big questions and set against them, and the huge challenges of the COVID pandemic, a spat about elective repair of unruptured AAA seems insignificant. But the themes raised when thinking about provision of AAA repair are an illustrative worked example in microcosm. Recovery from the pandemic urgently requires that, across the entire NHS, we allocate resource where it is most effective, rather than on the basis of special pleading or the misguided notion that doing nothing represents a medical or moral failure. I’m aware this is not everyones cup of tea!

Where do we go from here?

I think we need to consider carefully the language we use about AAAs and their repair: language has a powerful effect on thinking and constructs meaning. Elective AAA repair is predominantly an exercise in risk factor management in a multimorbid population, not a life saving intervention. While there has been a (thankful) move away from ‘ticking time bomb’, words like ‘threshold’ and ‘turndown’ imply a necessity for repair that is unsupported by the evidence base. They create a psychological momentum toward intervention that takes conscious effort to halt. ‘Likely (or unlikely) to benefit from repair’ seems more appropriate, though it does not trip off the tongue.

More importantly, we need to understand more about AAA as a disease, not just about EVAR or open repair as ways of treating it. This is an essential shift in emphasis. Until we know more about the contemporary prognosis of people with AAA we will be unable to make decisions with them about whether repair is worthwhile (by whatever criteria we choose: clinical effectiveness, cost effectiveness, patient satisfaction or something else). Focussing solely on research into the outcomes after repair (with any technique) will always fail to provide an answer to the first question that we should ask: will this person benefit from having their AAA repaired? The paradox is that it is impossible to investigate the natural history of AAA if we continue to repair nearly all of them. And it is also possible that once we know the prognosis for people with AAA, fewer procedures will be undertaken: a professional problem for vascular specialists who enjoy the technical challenge of AAA repair or have built a career on it, and a financial one for the medical technology industry. Will we like what we find?

The future of AAA repair is in our hands. We can choose to focus on AAA repair technique or on the AAA and the person with it. So next time you go to a conference, or attend a seminar, a webinar or a course ask yourself what is being addressed: technique or disease? When key opinion leaders speak at tentpole events like CIRSE, LINC, Cx, SIR and BSIR ask them: “Who should not get repair and who should?”, “Does cost effectiveness matter?”. Do their answers convince you? Are these questions they are interested in? Only by challenging can we shift the frame of reference.

As for NICE, I still believe it is of immense value as an organisation. But if you do get involved (and despite everything I would probably recommend it) be prepared to have some of your idealism and enthusiasm tarnished by political expediency. I wonder whether the medical profession and wider society are ready for some of the conclusions that flow inevitably from a consistent implementation of NICE’s principles.

Further reading:

A response to Balancing evidence in guidelines – an essay (BMJ)

NICE’s AAA guideline – an unexplained U-turn (BMJ opinion)

Two responses (from NICE and from the VSGBI) to the BJS editorial referenced in the first paragraph