[The statistical literacy of "my" patient].

The fundamental questions asked by the patient to the doctor are: "What is the best cure for my disease?"; "How likely am I to benefit from the intervention you propose?". To answer on a scientific basis, the doctor can use seven parameters: 1) the relative reduction of the risk; 2) its absolute reduction; 3) the necessary number of patients to be treated to obtain a benefit; 4) the number of patients to be treated to avoid an adverse event; 5) average life time gained; 6) average life time gained in good health; 7) the residual risk.The doctor, not a statistician or scientist, must explain to the patient the reason for his proposals, to pass from consent to sharing; this requires strong commitment and cultural growth of both the patient and the doctor. To avoid purely declamatory positions, it is necessary to adopt some tools such as the scientific method and risk management but above all statistics. If medicine has been defined as "the science of uncertainty and the art of probability", statistics is the science of probability and the art of uncertainty, that physicians and patients cannot do without to share their important decisions in the field of health.