Monday, May 2, 2011

Statin Statistics: Lies and Deception

In an independent meta-analysis (when a number of studies are put together to achieve more statistical power) of randomized controlled trials in patients without CVD, statin therapy decreased the incidence of major coronary and cerebrovascular events and revascularizations but not coronary heart disease or overall mortality.(1) Taking statins for a number of years will not reduce mortality: “Primary prevention with statins provides only small and clinically hardly relevant improvement of cardiovascular morbidity/mortality.”(2) “Hardly relevant” means there is virtually no clinical benefit; as the authors of these particular studies are independent, they gain nothing by stating this. Another review found that “current clinical evidence does not demonstrate that titrating lipid therapy (trying to lower cholesterol with statins) to achieve proposed low LDL cholesterol levels is beneficial or safe.”(3) In other words, lowering lipids has no real benefit and has the potential for adverse effects. Following up on this, in a major independent review of studies funded by the Ministry of Health of British Columbia (Canada) on statins and primary prevention, researchers reported that “statins have not been shown to provide an overall health benefit in primary prevention trials.”(4) This is a government report carried out by an independent university yet its findings are still ignored.

The problem really comes down to vested interests and the abuse of statistics. To overcome the limitations of small studies, vested parties combine many studies into a meta-analysis. The researchers themselves select the studies used in the meta-analysis. A fundamental problem is that researchers with direct links to drug companies have the authority to select the most positive studies and ignore the rest—including independent studies not funded by pharmaceutical companies. Despite this, they have still not been able to show any clinically significant findings.

As readers of the scientific journals, we should not be confused between statistical significance and clinical significance. For an outcome to be “statistically significant” means that the outcome was likely result of the treatment—whether the result was 100% effective or less than 0.1% effective. That is, if you treat 1,000 people to save one life (0.1%) it may be statistically significant but it is not clinically significant. “Clinical significance” means 20% to 30% or more. The drug companies’ most positive studies on statins for prevention of CVD report statistical significance, mostly 1% or less, and none have found any clinical significance.
Busy medical professionals don’t have time to review the statistics; few of them may be aware of the different ways the statistics are manipulated. So if the experienced professionals don’t understand the results of these studies, how do we expect the media or public to understand?

(1) Thavendiranathan, P., A. Bagai, et al. (2006). "Primary prevention of cardiovascular diseases with statin therapy: A meta-analysis of randomized controlled trials." Archives of Internal Medicine 166: 2307-2313.

(2) Vrecer, M., S. Turk, et al. (2003). "Use of statins in primary and secondary prevention of coronary heart disease and ischemic stroke. Meta-analysis of randomized trials." International Journal of Clinical Pharmacology and Therapeutics 41(12): 567-577.

(3) Hayward, R.A., T.P. Hofer, et al. (2006). "Narrative review: Lack of evidence for recommended low-density lipoprotein treatment targets: A solvable problem." Annals of Internal Medicine 145(7): 520-530.

(4) University of British Columbia (2003). "Do statins have a role in primary prevention? A review by the Therapeutics Initiative of the Department of Pharmacology & Therapeutics of the University of British Columbia." Therapeutics Letter (48).

1 comment:

  1. Of particular interest to me is Statins. I was prescribed them in 2009 due to high Cholesterol levels. After 3 months of being on them I stopped due to terrible side affects. I did not want to go on them because I had done some research on them after my mother died in 1999 from a massive heart attack while on statins. She had been on them for 6 years. She had kept a daily diary prior to her death. Each day she was saying she had headaches, muscle pain, sweats, muscle weakness.

    My Dr has just run a battery of test on me because my Cholesterol is 6.9 Much to her annoyance I will not be going on the statins. I eat healthy, am within normal weight range for my height.