Thompson S G, Pocock S J
Department of Epidemiology and Population Sciences, London School of Hygiene and Tropical Medicine, U.K.
J Clin Epidemiol. 1990;43(8):783-9. doi: 10.1016/0895-4356(90)90238-k.
The reliability of screening for high serum total cholesterol is adversely affected by the variability of cholesterol levels over time. This problem is investigated using data on repeated cholesterol measurements for 14,600 men and women in the MRC Mild Hypertension Trial. For measurements 1 year apart, the within-person coefficient of variation (CV) is 7%, which is substantial compared with the between-person CV of 15%. In a screening programme, this within-person variability may lead to the misclassification of individuals and inappropriate intervention. For example, 28% of middle-aged British men with a single cholesterol measurement above 6.9 mmol/l have a long-term average cholesterol below that value even without intervention. Using averages of several cholesterol measurements reduces, but does not eliminate, these problems. Furthermore, monitoring the effect of interventions in individuals by sequential cholesterol measurement may be unhelpful or even misleading. These problems cast serious doubt on the value of general population screening for high cholesterol levels.
血清总胆固醇水平随时间的变化会对高血清总胆固醇筛查的可靠性产生不利影响。利用医学研究委员会轻度高血压试验中14600名男性和女性的重复胆固醇测量数据对这一问题进行了调查。对于间隔1年的测量，个体内变异系数（CV）为7%，与个体间15%的变异系数相比相当大。在筛查项目中，这种个体内变异性可能导致个体的错误分类和不适当的干预。例如，单次胆固醇测量高于6.9 mmol/l的中年英国男性中，即使不进行干预，也有28%的人长期平均胆固醇水平低于该值。使用多次胆固醇测量的平均值可以减少但不能消除这些问题。此外，通过连续胆固醇测量来监测个体干预效果可能毫无帮助甚至会产生误导。这些问题严重质疑了对普通人群进行高胆固醇水平筛查的价值。
