[Evidence-based health services research--a short review and implications]

Health services research aims to generate knowledge about care processes of people with illnesses who access health-care services. In addition, the consequences of those processes in the care routine concerning the involved persons and the health system are analyzed. CONCEPT OF THE THEORETICAL WORK: In the first part of the manuscript, an overview concerning the current definitions and subsumptions of the concept of health services research is given. The second part of the manuscript focuses on demonstrating how evidence-based health services research can be used to enable optimization of the care system. The concept is called the "circle of care optimization". In the first step the current care situation concerning its deficits and their reasons is analyzed. In the second step a relevant care goal is defined. In the third step an improvement of an existing care process is developed to achieve the defined care goal. In the fourth step, a comparative empirical study with a high-quality study design is carried out, to assess whether the improved care process is superior to the current care as usual. A health economic evaluation will be performed if applicable. If the results show no or only small advantages, the "circle" starts again with step 3. However, if the results show a significant effect in favour of the new care process and are relevant for the delivery of care and efficient in the context of health economics, a fifth step will be performed which involves developing and testing strategies for implementation. Where relevant, the consequences of implementation are investigated in a sixth step. A "best-practice" practical example is demonstrated to illustrate the "circle of care optimization".

conclusions are derived by illustrating future challenges for health services research.