Clinical studies with captopril treatment of hypertensive patients

The leading principles of biometrical design, evaluation and decision making in biomedicine can be summarized as follows: (1) formulation of the problem to be solved and of the specific question(s) to be answered; (2) definition of the population in study, ways of sampling and manoeuvres (treatments); (3) determining the kind and number of variables (time intervals of measurement, investigated biomedical parameters); (4) performing the pilot study if necessary (to arrange randomized blocks, to form hypotheses); (5) formulation of zero (alternative) hypothesis, setting the values of alpha(beta) risk; (6) ordering the sample sizes; (7) testing the type of statistical distribution and the homoscedasticity of the obtained data; (8) calculation of the point and interval (confidence, tolerance) estimates; (9) performing the chosen tests, e.g. on the significance of differences or correlations; and (10) the conclusions for science and practice, with eventual return to point (1) on a higher level of knowledge.