Bar-On E, Meyer S, Harari G, Porat S
Schneider Children's and Rabin Medical Center, Petah Tikva, Israel.
J Bone Joint Surg Br. 1998 Mar;80(2):321-4. doi: 10.1302/0301-620x.80b2.8381.
Ultrasonography of the hip was performed sequentially by two different examiners in 75 infants. The ultrasound strips were reviewed twice by three paediatric orthopaedic surgeons and classified by the Graf method. The intraobserver and interobserver agreement between the interpretations was analysed using simple and weighted kappa coefficients calculated for agreement on the Graf classification and for grouping as normal (types 1A to 2A), and abnormal requiring treatment (types 2B to 4). When examining the same ultrasound strip, intraobserver agreement for the Graf classification was substantial (mean kappa 0.61), but interobserver agreement was only moderate (kappa 0.50). For the grouping into normal and abnormal, the mean kappa value for intraobserver agreement was 0.67 and for interobserver agreement 0.57. Because of the significant differences in agreement between normal and abnormal hips, we analysed a subgroup of those with at least one abnormal interpretation. Intraobserver agreement within this subgroup showed moderate reliability (kappa 0.41), but interobserver agreement was only fair (kappa 0.28). Interpretations of two different strips performed sequentially showed significantly lower agreement with an intraobserver kappa value of 0.29 and an interobserver value of 0.28. In the subgroup with at least one abnormal reading, the intraobserver kappa was 0.09 and the interobserver 0.1. Our findings suggest that both the technique of performing ultrasonography and the interpretation of the image may influence the result.
75名婴儿的髋关节超声检查由两名不同的检查人员依次进行。超声图像条由三名小儿骨科医生复查两次，并采用Graf方法进行分类。使用为Graf分类一致性以及分为正常（1A至2A型）和需要治疗的异常（2B至4型）分组计算的简单和加权kappa系数，分析解释之间的观察者内和观察者间一致性。在检查相同的超声图像条时，观察者内对Graf分类的一致性较高（平均kappa值为0.61），但观察者间一致性仅为中等（kappa值为0.50）。对于分为正常和异常的分组，观察者内一致性的平均kappa值为0.67，观察者间一致性为0.57。由于正常和异常髋关节之间的一致性存在显著差异，我们分析了至少有一次异常解读的亚组。该亚组内的观察者内一致性显示可靠性中等（kappa值为0.41），但观察者间一致性仅为一般（kappa值为0.28）。依次进行的两次不同图像条的解读显示一致性显著降低，观察者内kappa值为0.29，观察者间值为0.28。在至少有一次异常读数的亚组中，观察者内kappa值为0.09，观察者间为0.1。我们的研究结果表明，进行超声检查的技术和图像解读都可能影响结果。
