Re: NICE, drug-eluting stents and the limits of trial data

Mark de Belder, ,
November 07, 2008

Dear Sir

Dr Mohindra raises interesting points.

As regards clinical effectiveness, we must not confuse effectiveness in reducing restenosis and the need for repeat treatment (about which there is no doubt) and the potential for a reduction in later morbidity and mortality (about which there is continuing debate). The point is that we cannot exclude the latter possibility and this raises the issue of sensitivity analyses in cost-effectiveness analyses. The NICE models of cost-effectiveness usually result in a black-and-white view of the world, when there are many criteria that influence treatment decisions in individual patients. There is considerable uncertainty in these economic models, which should be recognised.

Dr Mohindra writes that any balance to be struck is between value and cost, not between clinical and cost-effectiveness, with value being seen both in terms of effectiveness and how the patient perceives this. Many others have discussed the limitation of relying wholly on an assessment of cost per QALYs in this regard and so there is nothing new here. NICE itself has stated that it does not have a threshold at which cost- effectiveness becomes unacceptable, although greater reliance on other factors is required for costs per QALY of more than £20,000.(1) He is right to point out though that I did not highlight this distinction in my editorial.

As regards the cost of stents, he is right in pointing out that this is something that currently depends on market forces; because of this, the cost can vary across the country. I am informed that the NICE committee had some difficulty dealing with this issue and ultimately decided to use an “average” cost of a bare metal stent, although for some reason they were provided with costs that were significantly lower than the costs identified by other means.

The value of a treatment as perceived by the patient is clearly very important. Take a “low risk” scenario where a patient treated with a bare metal stent has a 10% risk of angiographic restenosis and a clinical restenosis rate of 5% (i.e. a 1 in 20 chance of requiring a second treatment). For the same patient a drug eluting stent might offer a 5-6% chance of angiographic restenosis with a 2-3% chance of clinical restenosis (i.e. a 1 in 50 chance of requiring a second treatment). I don’t think many patients would find this choice very difficult but, depending on the relative costs of the stents, the NHS might find the 2-3% absolute difference unacceptable. One would have to be extremely sure of the reliability of cost-effectiveness analyses before denying this benefit to patients.

Because value is more difficult to establish than effectiveness, the current NICE methodology puts great pressure on clinicians to deny patients a superior treatment. In calling for this difference between effectiveness and value to be considered, Dr Mohindra calls for greater involvement of politicians in the process and yet NICE claims to be an “independent body”. He has not outlined what sort of involvement he would find helpful. There is a possibility that greater political involvement might lead to a reduction in the range of cost per QALYs that is deemed acceptable and so greater political involvement might make matters worse rather than better. Politicians in committee will always ask for a line to be drawn somewhere (although they sometimes react differently when confronted with a specific constituent’s medical problems), whereas patient groups and clinicians will always want what is “best”, regardless of cost. Some system is needed if only to avoid “the tragedy of commons”, whereby the individual demand by every patient for the currently best treatment regardless of cost leads to a level of healthcare spending that cannot be provided.(2) Introducing an ethicist into the process might help, if only to outline the dilemmas when cost-effectiveness analyses fall into the zone when additional justification is required to support the use of a new treatment.

Dr Mohindra has written elsewhere about the “affordability gap”, i.e. the gap between evidence-based treatments and NICE-approved treatments.(3) This is currently under great scrutiny, especially in the world of cancer treatment, where we might see that the value of a few additional weeks of life outweighs the results of cost-effectiveness analyses. In a recent presentation to the British Cardiovascular Society, I suggested that NICE does affect the clinician’s role as the patient’s advocate, but its system of appraisal, however imperfect, does at least provide a societal framework that both doctors and clinicians can live with as long as it is fair, consistent, intellectually robust and transparent. Many feel that the NICE review of drug-eluting stents has been anything but.

The debate about how to value a treatment will continue.

Yours sincerely

Mark de Belder

1. Raftery J. Review of NICE’s recommendations, 1999-2005. Br.Med.J. 2006;332:1266-8

2. Ferner RE, McDowell SE. How NICE may be outflanked. Br.Med.J. 2006;332:1268-71

3. Mohindra RK, Hall JA. Desmond’s non-NICE choice: dilemmas from drug-eluting stents in the affordability gap. Clinical Ethics 2006;192:105 -8

Conflict of Interest

None declared