Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài:Bench-to-bedside review: The importance of the precision of the reference technique in method comparison studies – with specific reference to the measurement of cardiac output. | Available online http content 13 1 201 Review Bench-to-bedside review The importance of the precision of the reference technique in method comparison studies - with specific reference to the measurement of cardiac output Maurizio Cecconi1 2 Andrew Rhodes2 Jan Poloniecki3 Giorgio Della Rocca1 and R Michael Grounds2 1 Department of Anesthesia and Intensive Care Azienda Ospedaliero Universitaria Udine Piazzale Santa Maria della Misericordia 33100 Udine Italy 2Department of Intensive Care Medicine St George s Hospital London SW17 0QT UK 3Community Health Sciences St George s University of London SW17 0RE UK Corresponding author Maurizio Cecconi mauriziocecconi@ Published 13 January 2009 Critical Care 2009 13 201 doi cc7129 This article is online at http content 13 1 201 2009 BioMed Central Ltd Abstract Bland-Altman analysis is used for assessing agreement between two measurements of the same clinical variable. In the field of cardiac output monitoring its results in terms of bias and limits of agreement are often difficult to interpret leading clinicians to use a cutoff of 30 in the percentage error in order to decide whether a new technique may be considered a good alternative. This percentage error of 30 arises from the assumption that the commonly used reference technique intermittent thermodilution has a precision of 20 or less. The combination of two precisions of 20 equates to a total error of which is commonly rounded up to 30 . Thus finding a percentage error of less than 30 should equate to the new tested technique having an error similar to the reference which therefore should be acceptable. In a worked example in this paper we discuss the limitations of this approach in particular in regard to the situation in which the reference technique may be either more or less precise than would normally be expected. This can lead to inappropriate conclusions being drawn from data acquired in validation studies of new .
