Georg Ivanovas From Autism to Humanism - systems theory in medicine

2.5 The limits of evidence based medicine

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f) surrogate parameter

RCTs investigate parameters. These parameters might be irrelevant for the expected outcome or for overall health, although obviousness based on reductionist research suggests something different (Ledford 2008). A classical example is sodium fluoride which raises bone density but makes it more brittle (Riggs et al 1990) (chap. 4.6).

This is why large studies regularly give rise to surprises turning away from widespread treatments which were induced on the basis of small studies. The CAST study (Echt et al 1991) proved more deaths through antiarrhythmics as through placebo. The WHI study (Chlebowski et al 2003) showed more breast cancers, more strokes, more thrombosis through hormone replacement therapy with oestrogen and progesterone in postmenopausal women, the standard therapy for many years. It also is correlated to a higher incidence of newly diagnosed asthma (Barr et al 2004). Similar risks are also true for monotherapy with oestrogen (Women's Health Initiative Steering Committee 2004). A year before the WHI study was published an editorial of New England Journal of Medicine stated under the header “Good news about oral contraceptives”: “The development of oral contraceptives stands as a major advance in women's health in the past century” (New England Journal of Medicine editorial 2002), as a study (CASH study) did not show any increase of breast cancers through HRT. But already then there had been trials showing the severe side effects of hormone replacement therapy, although some of them had not been published (McPherson 2004, McPherson/Hemminki 2004). Today’s scientific knowledge is: “Postmenopausal therapy with estrogen and progestin results in increased risks of disease, does not make asymptomatic women feel better, and does not improve cognition. There is no role for hormone therapy in the treatment of women without menopausal symptoms” (Grady 2003). This is quite a contrast to the knowledge of a few years before.

Presumably there are other harming drugs in use, widely described by physicians where a beneficial effect is proved by the means of EBM..


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