Monday, 31 January 2011

Statins—should we adjust the risk:benefit ratio?

reposted from:
crabsallover highlightskey pointscomments / links.
The prevailing opinion that statins are an elixir for long life was challenged with the recent publication of the Cochrane reviewStatins for the primary prevention of cardiovascular disease. After analysing 16 trial arms with 34 272 participants, the authors found no evidence of harm, and mortality, composite cardiovascular endpoints, and revascularisations were reduced. But they concluded: “caution should be taken in prescribing statins for primary prevention among people at low cardiovascular risk.”
The conclusion seems at odds with the findings. However, the authors found the evidence of insufficient quality to allow them to conclude differently; many trials included patients with a previous cardiovascular event, and the authors state that poor reporting of adverse events and selective reporting of outcomes contributed to their failure to draw a positive conclusion. They state that the evidence is “impossible to disentangle without individual patient data”.
The authors' conclusion is also at odds with the recent Cholesterol Treatment Trialists' (CTT) Collaboration meta-analysis, published in The Lancet. Individual patient data from around 70 000 patients with no previous cardiovascular disease were analysed, and showed that statins significantly reduced the relative risk of a cardiovascular event by 0·75 per 1 mmol fall in LDL cholesterol.
Unfortunately, the media are quick to forget, and have reported the Cochrane's headline-grabbing details with scant regard for the preceding evidence. This approach will have left many patients at best bewildered. The media have also largely ignored the Cochrane authors' conclusion that the results support guidelines from the UK's National Institute of Health and Clinical Excellence, which recommends statins are considered for primary prevention in patients with an annual incidence of cardiovascular events of over 2%.
So what should general practitioners (GPs), who are faced with increasing numbers of low-risk patients worried about mildly raised cholesterol, do? The Cochrane review has muddied the water, but the available evidence shows that statins are safe, and evidence from the CTT Collaboration also shows that reductions in cholesterol per se can produce benefits. So, the simple answer is that GPs should do what they always have done—clearly explain the risks and benefits to patients so that the patient is able to choose the strategy that is best for them.

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