Department of Urology, Section of Pediatric Urology, Yale University, New Haven, Connecticut.
Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
Neurourol Urodyn. 2018 Aug;37(6):1913-1924. doi: 10.1002/nau.23585. Epub 2018 Apr 17.
Our hypothesis was to confirm whether an idealized voider flow equation (IVFE) that we created is more accurate than trying to rely on estimated flow rates in the same patient in two consecutive voids. We also looked to confirm whether flow index (FI) can be a proxy for voiding efficiency and to identify which FI was best; those based off our own IVFE equations or those derived from the commonly used power equations.
We used data from a previous study and calculated flow rates using our IVFE and the power equations. Descriptive statistics and non-parametric tests were performed along with error analysis using Bland Altman (BA) and accuracy analysis (AA).
Bland Altman (BA) analysis revealed that flows obtained from normal voiders voiding between 100 and 200 cc as well as from 50 cc to 115% of EBC are comparable and tend to be reproducible in subsequent voids. FI derived from the IVFE exhibit less bias than Qmax making it a better way to compare these voids. A comparison of Qmax and flow index for different combinations of volumes and PVR's was done utilizing BA and accuracy measures both indicating that FI was more reproducible.
The data support both of our hypothesis that flow index is a good measure of voiding efficiency. We have also shown that IVFE is a better and more accurate measure of calculating a flow index than the power equations regardless of the volume and PVR scenarios that are presented.
我们的假设是验证我们创建的理想化排空流方程（IVFE）是否比尝试在两次连续排空中依赖于同一患者的估计流速更准确。我们还试图确认流量指数（FI）是否可以作为排空效率的替代指标，并确定哪种 FI 更好；那些基于我们自己的 IVFE 方程的 FI，还是那些源自常用功率方程的 FI。
我们使用了先前研究的数据，并使用我们的 IVFE 和功率方程计算了流量。进行了描述性统计和非参数检验，并使用 Bland Altman（BA）和准确性分析（AA）进行了误差分析。
Bland Altman（BA）分析表明，从排空 100 至 200cc 以及排空 50 至 115% EBC 的正常排空者获得的流量是可比的，并且在随后的排空中具有可重复性。与 Qmax 相比，IVFE 衍生的 FI 偏差较小，因此是比较这些排空的更好方法。使用 BA 和准确性度量对不同体积和 PVR 组合的 Qmax 和流量指数进行了比较，均表明 FI 更具可重复性。
数据支持我们的两个假设，即流量指数是排空效率的良好衡量指标。我们还表明，无论呈现的体积和 PVR 情况如何，IVFE 都是计算流量指数的更好、更准确的方法，优于功率方程。
