Statin drugs have been used on a wide scale since
the early 1990s, following the success of clinical trials initiated a decade
earlier. In the primary prevention of deaths from coronary heart disease (CHD)
the subjects do not have clinically obvious disease - no angina, no previous
myocardial infarction (MI, "heart attack"). The definitive study was
in the West of Scotland, men aged 55–65 with serum cholesterol >6.5, the
subjects having the world's highest incidence of CHD deaths at 840 per 100,000
per year.
This corresponds to a mortality rate of 4.2% in the
untreated subjects after the five-year duration of the study. In the subjects
randomly assigned to pravastatin the mortality rate was 3.1%. This was an
absolute reduction of 1.1% (not very impressive) and a proportionate reduction
of 25% (this spin is used in publicity, much more impressive!). What it means in
practice is that for every 100 such men taking pravastatin for five years one
will not die, 4.2-3.1 (this is sometimes called the NNT, number needed to treat to
achieve one endpoint).
Since then, during a period of about 30 years since
the onset of the West of Scotland study (called WOSCOPS) several other studies
appeared and overall the proportionate mortality reduction was about 20%. But
also during this time the death rate from CHD has dropped enormously, and it
must be acknowledged for reasons that are not clear.
Currently in the UK and western Europe in general,
the death rate from CHD is about and probably now less than 20 per 100,000 per
year. This is 0.02% per year or 0.1% at five years, very different from the
time of the West of Scotland study. The proportionate reduction would be the
same, 20–25% but now we see the absolute reduction being from 0.1% to 0.08%.
This means that we must now give a statin to about 4,000 men aged 55–65 for
five years to prevent one death. Strictly speaking this applies to men in the
West of Scotland. With a lower disease incidence in the south-east of England,
we would need to give statins to about 8,000 men to prevent the one death..
The UK price of generic statins is about £0.1 per
day, which is a total of £1.46M per year to delay one death every five years in
the West of Scotland. Is this good value for money? The propriety price is
about £1 per day, ten times greater.
The UK price of generic statins is about £0.1 per
day, which is a total of £1.46M per year to delay one death very five years. Is
this good value for money? The propriety price is about £1 per day, ten times
greater.
In the west of Scotland at the time of the study
the death rate from CHD of men aged 35–44 was one tenth that of the older men
studied. This means that today we would need to give statins to about 40,000
younger men to prevent one death every five years (annual cost = £14.6M), and
for women more than twice this.
The general advice from NICE in the UK is that about £20,000–30,000 would be an appropriate expenditure to achieve one year of good quality life. At this return we would expect the young man whose life is prolonged to live for another 500 active years. NICE has not made an up-to-date judgment on statin
therapy.
The era of statin therapy must now draw to an end,
just as the epidemic of CHD has almost come to an end.
It is unlikely that this information will officially enter the public domain.
It is unlikely that this information will officially enter the public domain.
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