Barbieri Cristiane, Cecatti Jose G, Souza Carla E, Marussi Emilio F, Costa Jose V
Department of Obstetrics and Gynecology, University of Campinas, Brazil.
Reprod Health. 2008 Oct 15;5:5. doi: 10.1186/1742-4755-5-5.
The purpose of the study was to evaluate inter- and intra-observer variability in sonographic measurements of the cross-sectional area of the umbilical cord and the diameters of its vessels in low-risk pregnancies of 12 to 40 weeks of gestation.
A prospective cross sectional study was performed in 221 pregnant women at different gestational ages. Measurements were carried out also by a second observer to evaluate inter-observer variability and repeated once again by the first observer to assess intra-observer variability. The linear correlation between the measurements (Spearman's coefficient of correlation) and their reliability through the intraclass correlation coefficient (ICC), the Cronbach's alpha coefficient and the limits of agreement proposed by Bland and Altman were evaluated.
The results showed that inter-observer and intra-observer variability did not show any significant difference between examiners. A good linear correlation between the measurements and reliability was obtained, with values of R, ICC and Cronbach's alpha all above the standard limits.
It is possible to conclude that inter- and intra-observer variability in the measurements of the umbilical cord and its vessels was small; their reliability and agreement were good.
本研究的目的是评估妊娠12至40周低风险孕妇脐带横截面积及其血管直径超声测量的观察者间和观察者内变异性。
对221名不同孕周的孕妇进行了一项前瞻性横断面研究。由第二名观察者进行测量以评估观察者间变异性，第一名观察者再次测量以评估观察者内变异性。通过组内相关系数（ICC）、克朗巴赫α系数以及布兰德和奥特曼提出的一致性界限来评估测量值之间的线性相关性（斯皮尔曼相关系数）及其可靠性。
结果表明，观察者间和观察者内变异性在检查者之间未显示出任何显著差异。测量值与可靠性之间获得了良好的线性相关性，R、ICC和克朗巴赫α值均高于标准界限。
可以得出结论，脐带及其血管测量的观察者间和观察者内变异性较小；其可靠性和一致性良好。
