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NEWS: Susan Mayor Researchers claim clinical trials are reported with misleading statistics BMJ 2002; 324: 1353a [Full text]

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The big power

Rosanna Velleca Lima   (9 June 2002)

Chance of surviving with and without treatment

Uffe Ravnskov   (18 June 2002)

Re: Chance of surviving with and without treatment

David Kerr   (20 June 2002)

The big power 9 June 2002
Rosanna Velleca Lima, Researchers claim clinical rilas are rported with misleading statisitics BC, Vancouver, V9G H7P Send response to journal: Re: The big power	I have always thought that doctors are continually subjected to pressure from the pharmaceutical industry and what a pressure. I used to be a researcher and depending how your data are shown you can show whatever you intend to. So caution and chicken soup is always clever whenever dealing with an endless number of new wonder drugs. Statistical background is fundamental when analysing any medical article and unfortunately not everybody has it to the proper extent. So I cannot feel free of a feeling of being trapped in the pharmaceutical net.
Chance of surviving with and without treatment 18 June 2002
Uffe Ravnskov Magle Stora Kyrkogata 9, S-22350 Lund, Sweden Send response to journal: Re: Chance of surviving with and without treatment	Prevention is better than cure, but the effect of most preventive measures is trivial.  The relative risk reduction is therefore highly misleading, as pointed out by Nuovo et al. (1), but even the absolute risk reduction, or number needed to treat, means almost nothing to most patients.. For this group it is much more ‘honest’ and effective to provide the figures that represent their chances of surviving with and without treatment.      To give an impression of the small improvement that is achieved by commonly used preventive measures I have calculated the chance of surviving with and without treatment of hypertension, and with and without treatment of hypercholesterolaemia (table).   For hypertension I have used the figures from a meta-analysis of seventeen controlled, randomised trials (2). For hypercholesterolaemia I have used the data from the 4S (3) , as it demonstrated the most favourable outcomes in patients with established cardiovascular disease, and the data from the WOSCOPS trial (4) as this trial demonstrated the most favourable outcome in healthy individuals with high cholesterol. In both trials I have chosen the figures for total mortality, because I assume that this is the most relevant figure for most patients, and because no bias is associated with that outcome. For the hypertension trials total cardiovascular mortality is the measurement used, because a meta-analytic calculation of total mortality was not performed.                                                                                             Table. Benefits from treatment of high blood pressure and of high cholesterol BP lowering 4S WOSCOPS Relative risk reduction; %  -20 -29 -21 Absolute risk reduction; % -0.8 -3.3 -0.9 Chance of surviving without treatment; % 96 88.5 90.6 Chance of surviving with treatment; % 96.8 91.8 91.4 As mentioned, these figures are the most optimistic available. For instance, in many of the studies that were included in the meta-analysis on hypertension, total mortality was not reduced significantly. Further, the results from the most recent secondary preventive statin trial HPS were only half as good as those from 4S (5); and total mortality in the first primary preventive statin trial EXCEL was increased in the treatment group (6). If patients were given these odds, and then clearly informed about possible side effects from treatment, I guess that most of them might choose to spend their money on horse racing.   Nuovo J, Melnikow J, Chang D. Reporting Number Needed to Treat and Absolute Risk Reduction in Randomized Controlled Trials. JAMA 2002;287:2813-4 Hebert PR, Moser, M, Mayer J, Hennekens CH. Recent evidence on drug therapy of mild to moderate hypertension an decreased risk of coronary heart disease. Arch Int Med 1993;153:578-81. Randomised trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian Simvastatin Survival Study (4S) Lancet 1994;344:1383-9. Shepherd J, Cobbe SM, Ford I, Isles CG, Lorimer AR, Macfarlane PW, McKillop JH, Packard CJ, for the West of Scotland Coronary Prevention Study Group. Prevention of coronary heart disease with pravastatine in men with hypercholesterolemia. N Engl J Med 1987;333:1301-7. Ravnskov U. Statins as the new Aspirin. Conclusions from the heart protection study were premature. BMJ 2002;324:789. Bradford RH, Shear CL, Chremos AN, Dujovne C, Downton M, Franklin FA, Gould AL, Hesney M, Higgins J, Hurley DP, et al. Expanded Clinical Evaluation of Lovastatin (EXCEL) study results. I. Efficacy in modifying plasma lipoproteins and adverse event profile in 8245 patients with moderate hypercholesterolemia. Arch Intern Med 1991;151:43-9.
Re: Chance of surviving with and without treatment 20 June 2002
David Kerr, Consultant Physician Bournemouth Diabetes and Endocrine Centre Send response to journal: Re: Re: Chance of surviving with and without treatment	I guess it would be even more "honest" if time is involved in discussions with patients. Will the pill delay death and for how long? Survival is a relative term within the human condition.