Norwegian Quality Improvement of Primary Care Laboratories-NOKLUS, Haraldsplass Hospital, Bergen, Norway.
Clin Chem. 2012 Sep;58(9):1306-13. doi: 10.1373/clinchem.2012.187781. Epub 2012 Jul 3.
Reliable estimates of within-person biological variation and reference change value are of great importance when interpreting test results, monitoring patients, and setting quality specifications. Little information has been published regarding what experimental design is optimal to achieve the best estimates of within-person biological variation.
Expected CIs were calculated for different balanced designs for a 2-level nested variance analysis model with varying analytical imprecision. We also simulated data sets based on the model to calculate the power of different study designs for detection of within-person biological variation.
The reliability of an estimate for biological variation and a study's power is very much influenced by the study design and by the ratio between analytical imprecision and within-person biological variation. For a fixed number of measurements, it is preferable to have a high number of samples from each individual. Shortcomings in analytical imprecision can be controlled by increasing the number of replicates.
The design of an experiment to estimate biological variation should take into account the analytical imprecision of the method and focus on obtaining the highest possible reliability. Estimates of biological variation should always be reported with CIs.
在解释检测结果、监测患者和制定质量规范时，可靠的个体内生物学变异和参考变化值估计非常重要。关于为了获得最佳个体内生物学变异估计值，哪种实验设计是最优的，相关信息发表的很少。
对于具有不同分析不精密度的 2 级嵌套方差分析模型，为不同平衡设计计算了预期置信区间。我们还基于该模型模拟了数据集，以计算不同研究设计检测个体内生物学变异的能力。
个体内变异的估计值的可靠性和研究的能力在很大程度上受到研究设计和分析不精密度与个体内生物学变异之间的比值的影响。对于固定数量的测量，最好从每个个体获得大量样本。通过增加重复次数可以控制分析不精密度的不足。
为估计生物学变异而设计的实验应考虑方法的分析不精密度，并侧重于获得尽可能高的可靠性。应始终报告生物学变异的估计值及其置信区间。
