Fredriks D A, Coleman R W
School of Pharmacy, University of the Pacific, Stockton, CA.
Clin Pharm. 1991 Dec;10(12):923-7.
The predictive performance of a nomogram for dosing warfarin was compared with that of a computer program. The nomogram and the computer program were developed from the log-linear model describing warfarin pharmacodynamics at steady state. The nomogram's dose-response curves were generated by using previously reported pharmacodynamic and pharmacokinetic values for an outpatient population receiving warfarin. The series of dose-response curves were plotted by altering the pharmacodynamic values over a range of 3 standard deviations. The ability of the nomogram to predict the steady-state prothrombin time ratio (PTR) after an adjustment in the dosage of warfarin was evaluated, and the results were compared with those of a commercially available program involving Bayesian regression. Data for 65 outpatients were evaluated. The mean +/- S.D. nomogram-predicted, computer-predicted, and measured PTRs were 1.63 +/- 0.27, 1.64 +/- 0.24, and 1.66 +/- 0.23, respectively. The mean prediction errors for the nomogram and the computer program were -0.037 and -0.026, respectively, and the mean percent absolute prediction errors were 11.6% and 11.0%, respectively. Neither method was biased, and differences between the results for the two methods were not significant. The predictive performance of the warfarin dosing nomogram was comparable to that of the computer program.
将华法林剂量计算列线图的预测性能与计算机程序的预测性能进行了比较。该列线图和计算机程序是根据描述华法林稳态药效学的对数线性模型开发的。列线图的剂量反应曲线是通过使用先前报道的接受华法林治疗的门诊患者群体的药效学和药代动力学值生成的。通过在3个标准差范围内改变药效学值绘制了一系列剂量反应曲线。评估了列线图预测华法林剂量调整后稳态凝血酶原时间比值（PTR）的能力，并将结果与涉及贝叶斯回归的市售程序的结果进行了比较。对65名门诊患者的数据进行了评估。列线图预测、计算机预测和测量的PTR的平均值±标准差分别为1.63±0.27、1.64±0.24和1.66±0.23。列线图和计算机程序的平均预测误差分别为-0.037和-0.026，平均绝对预测误差分别为11.6%和11.0%。两种方法均无偏差，两种方法结果之间的差异不显著。华法林剂量计算列线图的预测性能与计算机程序相当。
