NICE, drug-eluting stents and the limits of trial data
SIR, Dr M De Belder asks the question how to determine the worth of drug-eluting stent? (1) The answer to this question does not lie in the trial data. The function of the trial data is to establish the extent of clinical-effectiveness to a given degree of certainty. In this context, whilst a trend may be hypothesis generating it does not establish clinical -effectiveness.
There is no balance between clinical and cost-effectiveness. Clinical effectiveness necessarily precedes cost-effectiveness. If there is a balance to be struck it lies between value and cost. The cost is set by the market and by negotiation between the respective parties. Once this is settled the remaining key variable left to be determined is the value placed upon the degree of benefit demonstrated by the clinical trial evidence.
The value of the intervention to the patient as perceived by the NHS has to be balanced against its cost to the NHS as payer. It is this combination of clinical-effectiveness, cost and value (2) that presently falls to be considered by NICE.
Importantly, observe that the value to the patient of the treatment is judged not by the patient but by the payer. Because of this critical point the process should possess a stronger political component than it presently does. This is because it is the politicians and not NICE who are directly accountable to the key stakeholders i.e. the public whose dual guise as patients and tax payers drives this dilemma. (3)
Questions of clinical effectiveness can yield to randomised controlled clinical trials. However it is clear, from the principle of fact-value distinction first expressed by David Hume (4), that the value of an intervention cannot be determined from the trial data because trial data only ever returns a factual conclusion. Questions of value do yield to the principles of ethics. Questions of cost yield to principles of economics.
As the present situation with drug-eluting stents demonstrates there seems to be a need for doctors who can wield the full spectrum of such principles to be engaged with the aim of better protecting the interests of patients.
(1) Mark A de Belder NICE Guidelines for the use of drug-eluting stents: how do we establish worth? Published Online First: 26 August 2008. doi:10.1136/hrt.2008.144055
(2) Rawlins M., Culyer AJ. National Institute for Clinical Excellence and its value judgments. BMJ 2004;329:224-227
(3) Burke K. NICE needs sweeping changes to maintain credibility, say MPs. BMJ 2002;325:5
(4) Hume D. Treatise on Human Nature.1738. Book III part 1