[Scientific evidence in clinical practice: cost-effective and guaranteed quality of care].

According to the literature quality improvement methods were implemented successfully under various circumstances in many countries, through almost countless ways in order to achieve diverse quality improvement goals. Evidence suggests that quality improvement can be achieved through appropriate implementation of various methods. Literature on the effects of quality assurance on cost is relatively limited in number, however, the relation between the cost and quality is an issue of universal interest. Without any public consensus about what is meant by either quality or cost containment, it is difficult to evaluate their relation to each other fairly. However, there is sufficient support for the hypothesis that it is not too much quality, but rather too low quality that creates costs.