College of Medical Laboratory, Dalian Medical University, Dalian 116044, China.
Biomed Res Int. 2019 Aug 5;2019:8693719. doi: 10.1155/2019/8693719. eCollection 2019.
The purpose of this study was to describe variations of different cardinal frequency by using angle compared index (ACI).
The basic principle of the analysis model is to comprehensively consider changes in both the ratio and absolute value as follows: ACI = arctan {Pd⁎(1-Pc) / [Pc⁎(1-Pd)]} + arctan (Pd - Pc) - 45, where Pd represent percentage of disease occurrence in disease group and Pc represent that in control group. The range of ACI was (0~90). Thus, ACIs from different cardinal frequency are comparable.
When biomarkers with similar ratio value, absolute value, or ACI but different positive frequencies were combined, although three indexes (ratio value, absolute value, or ACI) increased after two single biomarkers were combined, only ACI increased with similar amplitudes after two single biomarkers with the same ACI at different positive frequencies were combined.
The ACI provides a better understanding power of biomarker and may be a relatively good index for evaluating the complex events represented by different cardinal frequency from new systems.
本研究旨在使用角度比较指数（ACI）描述不同基数频率的变化。
分析模型的基本原理是全面考虑比值和绝对值的变化，如下所示：ACI=arctan[Pd*(1-Pc)/[Pc*(1-Pd)]]+arctan(Pd-Pc)-45，其中 Pd 表示疾病组中疾病发生的百分比，Pc 表示对照组中的百分比。ACI 的范围是（0~90）。因此，来自不同基数频率的 ACIs 是可比较的。
当具有相似比值、绝对值或 ACI 但阳性频率不同的生物标志物组合时，尽管在两种单一生物标志物组合后，三个指标（比值、绝对值或 ACI）都增加了，但只有在两种具有相同 ACI 但阳性频率不同的单一生物标志物组合后，ACI 才以相似的幅度增加。
ACI 提供了对生物标志物更好的理解能力，并且可能是评估新系统中代表不同基数频率的复杂事件的相对较好的指标。
