Regional Anesthesia and Acute Pain ManagementRegional Anesthesia and Acute Pain Management1993-65082687-1394Eco-Vector3626010.17816/RA36260Research ArticlePlanning clinical research. Question #2: Choosing of endpointsTikhovaGalina P.gala@critical.ruFSBI “Karelian Research Center of Russian Academy of Science"1512201484677021072020Copyright © 2014, Eco-Vector2014The paper is devoted to the questions of correct choosing of endpoints that correspond the goal of the study as well as estimating of potential inaccuracy and bias of sample data due to particularities of different kind of endpoints. The author presents endpoints classification and considers various techniques to solve the problems arising from the endpoint nature.protocol of clinical studyendpoint of clinical studyпротокол клинического исследованияконечная точка исследования[Adams-Huet B., Ahn C. Bridging clinical investigators and statisticians: writing the statistical methodology for a research proposal. J Investig Med. 2009; 57(8): 818-824.][Prentice R.L. Surrogate endpoints in clinical trials: definition and operational criteria. Stat Med. 1989; 8(4): 431-440.]