Method against a principle

The basic answer to this question was given in the late thirties by the English statistican Bredford Hill who has offered 60 pills 10 free viagra a technique "randomed controllable tests". To receive convincing proofs of effectiveness of this or that intervention, it is necessary to part the patients participating in tests, on two groups — skilled and control. And to what of them the concrete patient will get 60 pills 10 free viagra, the case (in English "casual" — random should solve; from here and the name "randoming"). The control group should be exposed to all same influences, as the basic, except the most investigated intervention: we will tell, if studied substance enter syringe also the patient of control group do nyxes — the same volume and with the same frequency, but not containing a preparation. Thus ideal it is considered a so-called double blind method when neither patients, nor the doctor conducting test do not know, what group skilled, and what — control. The condition of patients in both groups should be expressed certain quantity indicators the difference between which is estimated by methods of mathematical statistics.

The reasons underlying this approach, are clear enough. Separation of patients into skilled and control groups allows to smooth specific features of a clinical course and to tap result of applied treatment. But all history of experimental medicine shows: 60 pills 10 free viagra if to leave this separation into the discretion of the doctor it can meaningly or unconsciously select in skilled group of patients with the best forecast, more "correct", typical clinical course, without the additional diseases strongly complicating a picture, at last, simply more disciplined and obligatory. So to work, of course, it is much easier, but if indicators of skilled group are better, than at control, nobody will tell, whether it is bound to studied influence or with initial dissimilarity of groups. Casual distribution allows to make both groups more homogeneous for all indicators — as studied in research, and that which influences nobody can expect. The same purpose — to exclude all other explanations of a difference in results, except influence of a new agent, — pursue also a double blind method (releasing results of tests from influence of enthusiasm of patients or the doctor-researcher), and the statistical data processing, allowing to be convinced that they cannot be explained accident influence.

Techniques of surgical operations too pass clinical tests. But demands to them others — the surgeon cannot operate blindfold
However clinic — not laboratory where actions of the researcher are limited only by demands of methodological cleanliness. One of corner stones of modern medicine — a principle of "the informed consent": any actions concerning the patient are possible only from its permission and approval (in special cases — for example, a long loss of consciousness or a serious mental disease — from a permission and approval of relatives). And before to ask the consent of the patient, the doctor is obliged to explain it sense of spent treatment and the restrictions bound to 60 pills 10 free viagra it and risks. And if different strategy of treatment (for example, operation or a medicamental course) the patient should tell about merits and demerits of each of them are possible and to leave a definitive choice on its discretion. It is clear that this approach will badly be compounded with a situation 60 pills 10 free viagra when not only sick, but also the doctor does not know what exactly it treat and whether treat in general. Without speaking about how from the point of view of a Hippocratic Oath the idea of control group — i.e. groups of the patients who absolutely not are not receiving special treatment looks.

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Actually in real researches platsebo-control (i.e. use as control of imitating influences — for example, injections of a normal saline solution or the tablets entirely consisting of a neutral excipient) is applied it is limited enough. Besides basic it has also purely practical bases: the new agent should help not simply from the given disease, but to help better, than already existing. Or, without conceding it in efficiency, to surpass in something the friend: to cheapness, safety, simplicity and convenience of application, absence of by-effects and etc. — differently its commercial prospects will be rather doubtful. And consequently on solving, the third, a phase of clinical tests a new agent 60 pills 10 free viagra compare usually not to zero, and with "the gold standard" — the best known treatment of the given illness. And platsebo-control, as a rule, use on the second phase (when as it was told above, it it is necessary to be convinced of basic effectiveness of an agent), on small groups of patients.