眼科临床研究中双眼数据的处理

Analysis of Correlated Two Eyes Data for Ophthalmic Cfinical Research

目的：描述如何选择合适的统计方法来分析眼科研究中的两眼数据。方法：针对在眼科研究中常用的两眼设计与配对设计中所产生的两眼数据，我们介绍了可用来分析两眼数据的各种统计方法，包括比较均值，比较两组中位数，两组率及两组生存率。并以不适合的和适合的统计分析方法比较了〈60岁与≥60岁患者的双眼眼压作为例子。结果：一只眼睛数据的分析只会导致偏差或降低比较效率。没有考虑两眼相关性的统计方法所得的P值（P=0．02）比考虑两眼相关性的统计方法的P值（P=0．098）小。结论：当两只眼睛的数据均适合用来分析时，应使用适当的统计分析方法来调整双眼间的相关性。只用单眼数据或者忽略双间眼相关分析可能会导致不正确的结论。

Objective： To describe the proper statistical approach in ophthalmic research for analyzing correlated data for contralateral eyes of the same subjects. Methods： For data from a paired design and a design for two eyes that are commonly used in ophthalmic research, we described the appropriate statistical approaches for analyzing the correlated data for both eyes of the same subjects. As an example, we compared the intraocular pressure between patients 〈 60 vs. 〉t 60 years of age, using the inappropriate and appropriate statistical analysis approaches. Results： The inappropriate analysis of data for one eye leaded only to a biased or inefficient estimate of the difference between two groups. The analysis of data for both eyes of the same subjects without accounting for inter-eye correlation had a smaller p-value （P=0.02） than the analysis that accounted for inter-eye correlation （P=0.098）. Conclusions： Appropriate statistical analytical approaches should be used to account for the inter-eye correlation. The statistical analysis using data for only one eye or ignoring the inter-eye correlation can lead to an incorrect conclusion.