Sadray Sima, Rezaee Saeed, Rezakhah Saeid
Laboratory of Pharmacokinetics and Biopharmaceutics, Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. Box 14155/6451, Tehran, Iran.
J Chromatogr B Analyt Technol Biomed Life Sci. 2003 Apr 25;787(2):293-302. doi: 10.1016/s1570-0232(02)00952-2.
Generalized least squares regression with variance function estimation was used to derive the calibration function for measurement of methotrexate plasma concentration and its results were compared with weighted least squares regression by usual weight factors and also with that of ordinary least squares method. In the calibration curve range of 0.05 to 100 microM, both heteroscedasticity and non-linearity were present therefore ordinary least squares linear regression methods could result in large errors in the calculation of methotrexate concentration. Generalized least squares regression with variance function estimation worked better than both the weighted regression with the usual weight factors and ordinary least squares regression and gave better estimates for methotrexate concentration.
采用具有方差函数估计的广义最小二乘回归来推导甲氨蝶呤血浆浓度测量的校准函数，并将其结果与采用常规权重因子的加权最小二乘回归以及普通最小二乘法的结果进行比较。在校准曲线范围为0.05至100微摩尔时，同时存在异方差性和非线性，因此普通最小二乘线性回归方法在计算甲氨蝶呤浓度时可能会导致较大误差。具有方差函数估计的广义最小二乘回归比采用常规权重因子的加权回归和普通最小二乘回归效果更好，并且对甲氨蝶呤浓度给出了更好的估计。
