Reproducibility of color Doppler imaging
Reproducibility of color Doppler imaging
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DOI：
10.1007/s00417-009-1178-3
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发表时间：
2009-11-01
影响因子：
2.7
通讯作者：
Harris, Alon
中科院分区：
文献类型：
--
作者：
Stalmans, Ingeborg;Siesky, Brent;Harris, Alon
本研究的目的是：（1）确定眼球后血管的彩色多普勒成像（CDI）测量和读数的受试者内和观察者间变异性，（2）比较非青光眼对照与青光眼患者中CDI参数变异性的差异，（3）为将来CDI研究提供最小样本量的计算。正常眼压性青光眼患者（n = 28），原发性开角型青光眼（n = 19）和年龄相当的非青光眼对照组（n = 22）接受了两次CDI，间隔1个月。使用（受试者内）变异系数量化CDI参数的变异性。基于这种变异性，最小样本量的计算，以指导设计未来的研究比较CDI组间和组内。一般来说，在受试者内的变异系数的测量1个月的间隔是可比的，以前报道的短期变化。青光眼患者的变异性高于非青光眼对照组。昏迷研究人群所需的最小样本量大于非昏迷对照人群。与使用舒张末期速度相比，使用收缩期峰值血流速度检测变化所需的患者组较少。使用交叉设计的研究需要较小的样本量比研究前后或特别平行design.This研究提供了广泛的信息，长期内的CDI测量的非青光眼控制以及青光眼患者的变异性。此外，使用三种不同的常用研究设计，为涉及青光眼患者以及非青光眼个体的研究提供了样本量计算。
The aims of this study were: (1) to determine the intra-subject and inter-observer variability of color Doppler imaging (CDI) measurements and readings of the retrobulbar blood vessels, (2) to compare the difference in variability of CDI parameters in non-glaucomatous controls versus glaucoma patients, and (3) to provide calculations of minimum sample sizes for future CDI studies.Patients with normal tension glaucoma (n = 28), primary open-angle glaucoma (n = 19) and non-glaucomatous controls of comparable age (n = 22) underwent CDI on two occasions 1 month apart. Variability in CDI parameters was quantified using (within-subject) coefficients of variation. Based on this variability, minimum sample sizes were calculated to guide the design of future studies comparing CDI between and within groups.In general, within-subject coefficients of variation for measurements 1 month apart were comparable to previously reported short-term variations. Variability was higher in glaucoma patients than in non-glaucomatous controls. The minimum sample size required for glaucomatous study populations is larger than for non-glaucomatous controls. Smaller patient groups are required to detect change using the peak systolic blood flow velocities than using end diastolic velocities. Studies using a cross-over design require smaller sample sizes than studies with a pre-post or particularly parallel design.This study provides extensive information on long-term intra-subject variability of CDI measurements in non-glaucomatous controls as well as glaucoma patients. Moreover, sample size calculations are provided for studies involving glaucoma patients as well as non-glaucomatous individuals, using three different commonly used study designs.