Cobb法测量先天性脊柱侧凸角度的可信度研究

Reliability analysis of the Cobb angle for patients with congenital scoliosis

目的评价Cobb法测量先天性脊柱侧凸角度的可靠性和可重复性。方法选取第四军医大学西京医院脊柱外科2010年1月—2013年12月收治的78例先天性脊柱侧凸患者的标准前后位全脊柱X线片。由5名医生利用Digimizer软件对全脊柱X线片测量Cobb角度，每人测量2次，2次测量间隔3周。记录测量的Cobb角度以及两次测量的差值。应用组内相关系数（ICC）判定可靠性和可重复性。结果Cobb法测量先天性脊柱侧凸角度的可信度范围为0．84—0．98，5名测量者两次测量间最大差值的范围为20°-57°，其中差值〉10°的例数范围为13～46例，同一测量者两次测量间的误差约8．5°；测量者之间的可信度为0．947，5名测量者在81°～110°组和〉110°组之间的ICC为0．623和0．822。结论Cobb法测量先天性脊柱侧凸可以获得较好的可靠性和可重复性，但是测量者内部以及测量者之间仍然出现较多且较大的误差，尤其在侧凸角度较大时，Cobb法测量先天性脊柱侧凸的准确性缺乏稳定性。

Objective To analyze the reliability of measurement of Cobb angle of the patients with congenital scoliosis. Methods Seventy-eight standard standing posteroanterior whole-spine radiographs of the patients with congenital scoliosis treated in Xijing hospital of Fourth Military Medical University from January 2010 to December 2013 were reviewed. Five doctors measured the Cobb angle twice by Digimizer software, with an interval of at least three weeks between the two measurements. The results of the Cobb angle and deviations between the two measurements were recorded. Both intraobserver and interobserver agreements were assessed with the intraclass correlation coefficient （ICC）. Results All ICC values representing intraobserver variability of observers ranged from 0. 84 to 0. 98. The biggest intraobserver indifference ranged from 20° to 57°, and there were 13 to 46 curves of which intraobserver indifference was more than 10° between five observers. The intraobserver variance was 8.5°. The ICC values representing intrerobserver variability of observers was 0. 947. Interobserver ICC values in 81 ° - 110° and 〉 110° groups were 0. 623 and 0. 822, respectively. Conclusions Applying Cobb method as a measurement tool to evaluate the congenital scoliosis is reliable in term of intra-and interobserver variability. But there still exists big difference between intra-and interobserver, especially for severe scoliosis, the accuracy of Cobb method deserves questionable.