Twisk J W, Kemper H C, Mellenbergh G J, van Mechelen W
Institute of Extramural Medicine, Vrije Universiteit, Amsterdam, The Netherlands.
Eur J Epidemiol. 1997 Apr;13(3):293-300. doi: 10.1023/a:1007373705865.
Because 'traditional' tracking analyses have some drawbacks, this paper presents a new method, which is based on generalized estimating equations (GEE). The new method is illustrated with data from the Amsterdam Growth and Health Study. In this observational longitudinal study six repeated measurements were carried out on 181 subjects (initial age 13 years) over a period of 15 years. Tracking was assessed for total cholesterol (TC), high density lipoprotein (HDL) and the TC/HDL ratio by calculating the odds ratio (OR) for subjects at risk at the age of 13 years regarding the development of their risk status over a 15 year period. These ORs can be interpreted as tracking coefficients. Three methods were compared: percentage of subjects who maintain their position in a certain risk group (i.e. univariate logistic regression), multivariate logistic regression and GEE. The three methods differ in the possibility of using all available data in the analysis and in the possibility of adjusting for certain covariates. Based on this, the GEE-approach seemed to be the most appropriate to calculate tracking coefficients for subjects at risk. When the risk groups were defined according to objective (absolute) risk values, for TC the GEE-OR was 10.1 (95% confidence interval (CI) 5.0-21.9), for HDL 14.4 (95% CI 7.2-28.7) and for the TC/HDL ratio 25.5 (95% CI 11.5-56.8). It can be concluded that the GEE-approach is very suitable to assess tracking for subjects at risk.
由于“传统”追踪分析存在一些缺点，本文提出了一种基于广义估计方程（GEE）的新方法。通过来自阿姆斯特丹生长与健康研究的数据对该新方法进行了说明。在这项观察性纵向研究中，对181名受试者（初始年龄13岁）在15年的时间里进行了6次重复测量。通过计算13岁有风险的受试者在15年期间其风险状态发展的优势比（OR），对总胆固醇（TC）、高密度脂蛋白（HDL）和TC/HDL比值的追踪情况进行了评估。这些OR可解释为追踪系数。比较了三种方法：在特定风险组中保持其位置的受试者百分比（即单变量逻辑回归）、多变量逻辑回归和GEE。这三种方法在分析中使用所有可用数据的可能性以及调整某些协变量的可能性方面存在差异。基于此，GEE方法似乎最适合计算有风险受试者的追踪系数。当根据客观（绝对）风险值定义风险组时，对于TC，GEE-OR为10.1（95%置信区间（CI）5.0 - 21.9），对于HDL为14.4（95%CI 7.2 - 28.7），对于TC/HDL比值为25.5（95%CI 11.5 - 56.8）。可以得出结论，GEE方法非常适合评估有风险受试者的追踪情况。
